Merge pull request #36 from JetBrains/codeviewer

Code Viewer Example

examples/codeviewer/.gitignore

@@ -0,0 +1,15 @@
+*.iml
+.gradle
+/local.properties
+/.idea
+/.idea/caches
+/.idea/libraries
+/.idea/modules.xml
+/.idea/workspace.xml
+/.idea/navEditor.xml
+/.idea/assetWizardSettings.xml
+.DS_Store
+build/
+/captures
+.externalNativeBuild
+.cxx

examples/codeviewer/.run/desktop.run.xml

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+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="desktop" type="GradleRunConfiguration" factoryName="Gradle">
+    <ExternalSystemSettings>
+      <option name="executionName" />
+      <option name="externalProjectPath" value="$PROJECT_DIR$/desktop" />
+      <option name="externalSystemIdString" value="GRADLE" />
+      <option name="scriptParameters" value="" />
+      <option name="taskDescriptions">
+        <list />
+      </option>
+      <option name="taskNames">
+        <list>
+          <option value="run" />
+        </list>
+      </option>
+      <option name="vmOptions" value="" />
+    </ExternalSystemSettings>
+    <GradleScriptDebugEnabled>true</GradleScriptDebugEnabled>
+    <method v="2" />
+  </configuration>
+</component>

examples/codeviewer/README.md

@@ -0,0 +1,7 @@
+MPP Code Viewer example for desktop/android written in Multiplatform Compose library.
+
+To run desktop application execute in a terminal:
+`./gradlew desktop:run`
+
+To install android application on device/emulator:
+'./gradlew installDebug'

examples/codeviewer/android/build.gradle.kts

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+plugins {
+    id("com.android.application")
+    kotlin("android")
+    id("org.jetbrains.compose")
+}
+
+android {
+    compileSdkVersion(30)
+
+    defaultConfig {
+        minSdkVersion(26)
+        targetSdkVersion(30)
+        versionCode = 1
+        versionName = "1.0"
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_1_8
+        targetCompatibility = JavaVersion.VERSION_1_8
+    }
+}
+
+dependencies {
+    implementation(project(":common"))
+}

examples/codeviewer/android/src/main/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="org.jetbrains.codeviewer">
+
+    <application
+        android:allowBackup="true"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/Theme.AppCompat.Light.NoActionBar">
+        <activity
+            android:name="MainActivity"
+            android:label="@string/app_name">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>

examples/codeviewer/android/src/main/assets/data/EditorView.kt

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+/**
+ * This file is an example (we can open it in android application)
+ */
+
+package org.jetbrains.codeviewer.ui.editor
+
+import androidx.compose.foundation.AmbientContentColor
+import androidx.compose.foundation.Text
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.material.CircularProgressIndicator
+import androidx.compose.material.Surface
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.drawOpacity
+import androidx.compose.ui.platform.DensityAmbient
+import androidx.compose.ui.text.AnnotatedString
+import androidx.compose.ui.text.SpanStyle
+import androidx.compose.ui.text.annotatedString
+import androidx.compose.ui.text.withStyle
+import androidx.compose.ui.unit.dp
+import org.jetbrains.codeviewer.platform.SelectionContainer
+import org.jetbrains.codeviewer.platform.VerticalScrollbar
+import org.jetbrains.codeviewer.platform.WithoutSelection
+import org.jetbrains.codeviewer.ui.common.AppTheme
+import org.jetbrains.codeviewer.ui.common.Fonts
+import org.jetbrains.codeviewer.ui.common.Settings
+import org.jetbrains.codeviewer.util.LazyColumnFor
+import org.jetbrains.codeviewer.util.loadable
+import org.jetbrains.codeviewer.util.loadableScoped
+import org.jetbrains.codeviewer.util.withoutWidthConstraints
+import kotlin.text.Regex.Companion.fromLiteral
+
+@Composable
+fun EditorView(model: Editor, settings: Settings) = key(model) {
+    with (DensityAmbient.current) {
+        SelectionContainer {
+            Surface(
+                Modifier.fillMaxSize(),
+                color = AppTheme.colors.backgroundDark,
+            ) {
+                val lines by loadableScoped(model.lines)
+
+                if (lines != null) {
+                    Box {
+                        Lines(lines!!, settings)
+                        Box(
+                            Modifier
+                                .offset(
+                                    x = settings.fontSize.toDp() * 0.5f * settings.maxLineSymbols
+                                )
+                                .width(1.dp)
+                                .fillMaxHeight()
+                                .background(AppTheme.colors.backgroundLight)
+                        )
+                    }
+                } else {
+                    CircularProgressIndicator(
+                        modifier = Modifier
+                            .size(36.dp)
+                            .padding(4.dp)
+                    )
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun Lines(lines: Editor.Lines, settings: Settings) = with(DensityAmbient.current) {
+    val maxNumber = remember(lines.lineNumberDigitCount) {
+        (1..lines.lineNumberDigitCount).joinToString(separator = "") { "9" }
+    }
+
+    Box(Modifier.fillMaxSize()) {
+        val scrollState = rememberLazyListState()
+        val lineHeight = settings.fontSize.toDp() * 1.6f
+
+        LazyColumnFor(
+            lines.size,
+            modifier = Modifier.fillMaxSize(),
+            state = scrollState,
+            itemContent = { index ->
+                val line: Editor.Line? by loadable { lines.get(index) }
+                Box(Modifier.height(lineHeight)) {
+                    if (line != null) {
+                        Line(Modifier.align(Alignment.CenterStart), maxNumber, line!!, settings)
+                    }
+                }
+            }
+        )
+
+        VerticalScrollbar(
+            Modifier.align(Alignment.CenterEnd),
+            scrollState,
+            lines.size,
+            lineHeight
+        )
+    }
+}
+
+// Поддержка русского языка
+// دعم اللغة العربية
+// 中文支持
+@Composable
+private fun Line(modifier: Modifier, maxNumber: String, line: Editor.Line, settings: Settings) {
+    Row(modifier = modifier) {
+        WithoutSelection {
+            Box {
+                LineNumber(maxNumber, Modifier.drawOpacity(0f), settings)
+                LineNumber(line.number.toString(), Modifier.align(Alignment.CenterEnd), settings)
+            }
+        }
+        LineContent(
+            line.content,
+            modifier = Modifier
+                .weight(1f)
+                .withoutWidthConstraints()
+                .padding(start = 28.dp, end = 12.dp),
+            settings = settings
+        )
+    }
+}
+
+@Composable
+private fun LineNumber(number: String, modifier: Modifier, settings: Settings) = Text(
+    text = number,
+    fontSize = settings.fontSize,
+    fontFamily = Fonts.jetbrainsMono(),
+    color = AmbientContentColor.current.copy(alpha = 0.30f),
+    modifier = modifier.padding(start = 12.dp)
+)
+
+@Composable
+private fun LineContent(content: Editor.Content, modifier: Modifier, settings: Settings) = Text(
+    text = if (content.isCode) {
+        codeString(content.value.value)
+    } else {
+        AnnotatedString(content.value.value)
+    },
+    fontSize = settings.fontSize,
+    fontFamily = Fonts.jetbrainsMono(),
+    modifier = modifier,
+    softWrap = false
+)
+
+private fun codeString(str: String) = annotatedString {
+    withStyle(AppTheme.code.simple) {
+        append(str.replace("\t", "    "))
+        addStyle(AppTheme.code.punctuation, ":")
+        addStyle(AppTheme.code.punctuation, "=")
+        addStyle(AppTheme.code.punctuation, "\"")
+        addStyle(AppTheme.code.punctuation, "[")
+        addStyle(AppTheme.code.punctuation, "]")
+        addStyle(AppTheme.code.punctuation, "{")
+        addStyle(AppTheme.code.punctuation, "}")
+        addStyle(AppTheme.code.punctuation, "(")
+        addStyle(AppTheme.code.punctuation, ")")
+        addStyle(AppTheme.code.punctuation, ",")
+        addStyle(AppTheme.code.keyword, "fun ")
+        addStyle(AppTheme.code.keyword, "val ")
+        addStyle(AppTheme.code.keyword, "var ")
+        addStyle(AppTheme.code.keyword, "private ")
+        addStyle(AppTheme.code.keyword, "internal ")
+        addStyle(AppTheme.code.keyword, "for ")
+        addStyle(AppTheme.code.keyword, "expect ")
+        addStyle(AppTheme.code.keyword, "actual ")
+        addStyle(AppTheme.code.keyword, "import ")
+        addStyle(AppTheme.code.keyword, "package ")
+        addStyle(AppTheme.code.value, "true")
+        addStyle(AppTheme.code.value, "false")
+        addStyle(AppTheme.code.value, Regex("[0-9]*"))
+        addStyle(AppTheme.code.annotation, Regex("^@[a-zA-Z_]*"))
+        addStyle(AppTheme.code.comment, Regex("^\\s*//.*"))
+    }
+}
+
+private fun AnnotatedString.Builder.addStyle(style: SpanStyle, regexp: String) {
+    addStyle(style, fromLiteral(regexp))
+}
+
+private fun AnnotatedString.Builder.addStyle(style: SpanStyle, regexp: Regex) {
+    for (result in regexp.findAll(toString())) {
+        addStyle(style, result.range.first, result.range.last + 1)
+    }
+}

examples/codeviewer/android/src/main/java/org/jetbrains/codeviewer/MainActivity.kt

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+package org.jetbrains.codeviewer
+
+import android.os.Bundle
+import androidx.appcompat.app.AppCompatActivity
+import androidx.compose.ui.platform.setContent
+import org.jetbrains.codeviewer.platform._HomeFolder
+import org.jetbrains.codeviewer.ui.MainView
+import java.io.File
+import java.io.FileOutputStream
+
+class MainActivity : AppCompatActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        copyAssets()
+        _HomeFolder = filesDir
+
+        setContent {
+            MainView()
+        }
+    }
+
+    private fun copyAssets() {
+        for (filename in assets.list("data")!!) {
+            assets.open("data/$filename").use { assetStream ->
+                val file = File(filesDir, filename)
+                FileOutputStream(file).use { fileStream ->
+                    assetStream.copyTo(fileStream)
+                }
+            }
+        }
+    }
+}

examples/codeviewer/android/src/main/res/drawable/ic_launcher_foreground.xml

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+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108"
+    android:tint="#FFFFFF">
+  <group android:scaleX="2.61"
+      android:scaleY="2.61"
+      android:translateX="22.68"
+      android:translateY="22.68">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M9.4,16.6L4.8,12l4.6,-4.6L8,6l-6,6 6,6 1.4,-1.4zM14.6,16.6l4.6,-4.6 -4.6,-4.6L16,6l6,6 -6,6 -1.4,-1.4z"/>
+  </group>
+</vector>

examples/codeviewer/android/src/main/res/mipmap-anydpi-v26/ic_launcher.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@color/ic_launcher_background"/>
+    <foreground android:drawable="@drawable/ic_launcher_foreground"/>
+</adaptive-icon>

examples/codeviewer/android/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@color/ic_launcher_background"/>
+    <foreground android:drawable="@drawable/ic_launcher_foreground"/>
+</adaptive-icon>

examples/codeviewer/android/src/main/res/values/ic_launcher_background.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <color name="ic_launcher_background">#3C3F41</color>
+</resources>

examples/codeviewer/android/src/main/res/values/strings.xml

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+<resources>
+    <string name="app_name">Code Viewer</string>
+</resources>

examples/codeviewer/build.gradle.kts

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+buildscript {
+    repositories {
+        google()
+        jcenter()
+        maven("https://maven.pkg.jetbrains.space/public/p/compose/dev")
+    }
+
+    dependencies {
+        // TODO/migrateToMaster 0.1.0-dev104 is built from "unmerged" branch,
+        //  replace it by version from androidx-master-dev when scrollbars will be merged
+        classpath("org.jetbrains.compose:compose-gradle-plugin:0.1.0-dev104")
+        classpath("com.android.tools.build:gradle:4.0.1")
+        classpath(kotlin("gradle-plugin", version = "1.4.0"))
+    }
+}
+
+allprojects {
+    repositories {
+        google()
+        jcenter()
+        maven("https://maven.pkg.jetbrains.space/public/p/compose/dev")
+    }
+}

examples/codeviewer/common/build.gradle.kts

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+import org.jetbrains.compose.compose
+
+plugins {
+    id("com.android.library")
+    kotlin("multiplatform")
+    id("org.jetbrains.compose")
+}
+
+kotlin {
+    android()
+    jvm("desktop")
+
+    sourceSets {
+        named("commonMain") {
+            dependencies {
+                api(compose.runtime)
+                api(compose.foundation)
+                api(compose.material)
+                api(compose.materialIconsExtended)
+            }
+        }
+        named("androidMain") {
+            kotlin.srcDirs("src/jvmMain/kotlin")
+            dependencies {
+                api("androidx.appcompat:appcompat:1.1.0")
+                api("androidx.core:core-ktx:1.3.1")
+            }
+        }
+        named("desktopMain") {
+            kotlin.srcDirs("src/jvmMain/kotlin")
+            resources.srcDirs("src/commonMain/resources")
+            dependencies {
+                api(compose.desktop.common)
+            }
+        }
+    }
+}
+
+project.extensions.findByType<com.android.build.gradle.LibraryExtension>()!!.apply {
+    sourceSets.findByName("main")?.apply {
+        res.srcDirs("src/commonMain/resources")
+    }
+}
+
+android {
+    compileSdkVersion(30)
+
+    defaultConfig {
+        minSdkVersion(21)
+        targetSdkVersion(30)
+        versionCode = 1
+        versionName = "1.0"
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_1_8
+        targetCompatibility = JavaVersion.VERSION_1_8
+    }
+
+    sourceSets {
+        named("main") {
+            manifest.srcFile("src/androidMain/AndroidManifest.xml")
+            res.srcDirs("src/androidMain/res")
+        }
+    }
+}

examples/codeviewer/common/src/androidMain/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<manifest package="org.jetbrains.codeviewer.common"/>

examples/codeviewer/common/src/androidMain/kotlin/org/jetbrains/codeviewer/platform/File.kt

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+package org.jetbrains.codeviewer.platform
+
+lateinit var _HomeFolder: java.io.File
+actual val HomeFolder: File get() = _HomeFolder.toProjectFile()

examples/codeviewer/common/src/androidMain/kotlin/org/jetbrains/codeviewer/platform/Mouse.kt

@@ -0,0 +1,12 @@
+package org.jetbrains.codeviewer.platform
+
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Offset
+
+actual fun Modifier.pointerMoveFilter(
+    onEnter: () -> Boolean,
+    onExit: () -> Boolean,
+    onMove: (Offset) -> Boolean
+): Modifier = this
+
+actual fun Modifier.cursorForHorizontalResize() = this

examples/codeviewer/common/src/androidMain/kotlin/org/jetbrains/codeviewer/platform/Resources.kt

@@ -0,0 +1,31 @@
+package org.jetbrains.codeviewer.platform
+
+import android.graphics.BitmapFactory
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.graphics.ImageAsset
+import androidx.compose.ui.graphics.asImageAsset
+import androidx.compose.ui.platform.ContextAmbient
+import androidx.compose.ui.text.font.Font
+import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.text.font.FontWeight
+import java.io.InputStream
+import java.net.URL
+
+@Composable
+actual fun imageResource(res: String): ImageAsset {
+    val context = ContextAmbient.current
+    val id = context.resources.getIdentifier(res, "drawable", context.packageName)
+    return androidx.compose.ui.res.imageResource(id)
+}
+
+actual suspend fun imageFromUrl(url: String): ImageAsset {
+    val bytes = URL(url).openStream().buffered().use(InputStream::readBytes)
+    return BitmapFactory.decodeByteArray(bytes, 0, bytes.size).asImageAsset()
+}
+
+@Composable
+actual fun font(name: String, res: String, weight: FontWeight, style: FontStyle): Font {
+    val context = ContextAmbient.current
+    val id = context.resources.getIdentifier(res, "font", context.packageName)
+    return androidx.compose.ui.text.font.font(id, weight, style)
+}

examples/codeviewer/common/src/androidMain/kotlin/org/jetbrains/codeviewer/platform/Scrollbar.kt

@@ -0,0 +1,21 @@
+package org.jetbrains.codeviewer.platform
+
+import androidx.compose.foundation.ScrollState
+import androidx.compose.foundation.lazy.LazyListState
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.Dp
+
+@Composable
+actual fun VerticalScrollbar(
+    modifier: Modifier,
+    scrollState: ScrollState
+) = Unit
+
+@Composable
+actual fun VerticalScrollbar(
+    modifier: Modifier,
+    scrollState: LazyListState,
+    itemCount: Int,
+    averageItemSize: Dp
+) = Unit

examples/codeviewer/common/src/androidMain/kotlin/org/jetbrains/codeviewer/platform/Selection.kt

@@ -0,0 +1,26 @@
+package org.jetbrains.codeviewer.platform
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.selection.Selection
+import androidx.compose.ui.selection.SelectionContainer
+
+@Composable
+actual fun SelectionContainer(children: @Composable () -> Unit) {
+    val selection = remember { mutableStateOf<Selection?>(null) }
+    SelectionContainer(
+        selection = selection.value,
+        onSelectionChange = { selection.value = it },
+        children = children
+    )
+}
+
+@Composable
+actual fun WithoutSelection(children: @Composable () -> Unit) {
+    SelectionContainer(
+        selection = null,
+        onSelectionChange = {},
+        children = children
+    )
+}

examples/codeviewer/common/src/androidMain/kotlin/org/jetbrains/codeviewer/platform/Theme.kt

@@ -0,0 +1,6 @@
+package org.jetbrains.codeviewer.platform
+
+import androidx.compose.runtime.Composable
+
+@Composable
+actual fun PlatformTheme(content: @Composable () -> Unit) = content()

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/platform/File.kt

@@ -0,0 +1,15 @@
+package org.jetbrains.codeviewer.platform
+
+import kotlinx.coroutines.CoroutineScope
+import org.jetbrains.codeviewer.util.TextLines
+
+expect val HomeFolder: File
+
+interface File {
+    val name: String
+    val isDirectory: Boolean
+    val children: List<File>
+    val hasChildren: Boolean
+
+    suspend fun readLines(backgroundScope: CoroutineScope): TextLines
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/platform/Mouse.kt

@@ -0,0 +1,12 @@
+package org.jetbrains.codeviewer.platform
+
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.geometry.Offset
+
+expect fun Modifier.pointerMoveFilter(
+    onEnter: () -> Boolean = { true },
+    onExit: () -> Boolean = { true },
+    onMove: (Offset) -> Boolean = { true }
+): Modifier
+
+expect fun Modifier.cursorForHorizontalResize(): Modifier

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/platform/Resources.kt

@@ -0,0 +1,15 @@
+package org.jetbrains.codeviewer.platform
+
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.graphics.ImageAsset
+import androidx.compose.ui.text.font.Font
+import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.text.font.FontWeight
+
+@Composable
+expect fun imageResource(res: String): ImageAsset
+
+expect suspend fun imageFromUrl(url: String): ImageAsset
+
+@Composable
+expect fun font(name: String, res: String, weight: FontWeight, style: FontStyle): Font

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/platform/Scrollbar.kt

@@ -0,0 +1,21 @@
+package org.jetbrains.codeviewer.platform
+
+import androidx.compose.foundation.ScrollState
+import androidx.compose.foundation.lazy.LazyListState
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.Dp
+
+@Composable
+expect fun VerticalScrollbar(
+    modifier: Modifier,
+    scrollState: ScrollState
+)
+
+@Composable
+expect fun VerticalScrollbar(
+    modifier: Modifier,
+    scrollState: LazyListState,
+    itemCount: Int,
+    averageItemSize: Dp
+)

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/platform/Selection.kt

@@ -0,0 +1,9 @@
+package org.jetbrains.codeviewer.platform
+
+import androidx.compose.runtime.Composable
+
+@Composable
+expect fun SelectionContainer(children: @Composable () -> Unit)
+
+@Composable
+expect fun WithoutSelection(children: @Composable () -> Unit)

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/platform/Theme.kt

@@ -0,0 +1,6 @@
+package org.jetbrains.codeviewer.platform
+
+import androidx.compose.runtime.Composable
+
+@Composable
+expect fun PlatformTheme(content: @Composable () -> Unit)

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/ui/CodeViewer.kt

@@ -0,0 +1,11 @@
+package org.jetbrains.codeviewer.ui
+
+import org.jetbrains.codeviewer.ui.common.Settings
+import org.jetbrains.codeviewer.ui.editor.Editors
+import org.jetbrains.codeviewer.ui.filetree.FileTree
+
+class CodeViewer(
+    val editors: Editors,
+    val fileTree: FileTree,
+    val settings: Settings
+)

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/ui/CodeViewerView.kt

@@ -0,0 +1,105 @@
+package org.jetbrains.codeviewer.ui
+
+import androidx.compose.animation.animate
+import androidx.compose.animation.core.Spring.StiffnessLow
+import androidx.compose.animation.core.SpringSpec
+import androidx.compose.foundation.AmbientContentColor
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.*
+import androidx.compose.material.Icon
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material.icons.filled.ArrowForward
+import androidx.compose.runtime.*
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.drawLayer
+import androidx.compose.ui.unit.dp
+import org.jetbrains.codeviewer.ui.editor.EditorEmptyView
+import org.jetbrains.codeviewer.ui.editor.EditorTabsView
+import org.jetbrains.codeviewer.ui.editor.EditorView
+import org.jetbrains.codeviewer.ui.filetree.FileTreeView
+import org.jetbrains.codeviewer.ui.filetree.FileTreeViewTabView
+import org.jetbrains.codeviewer.ui.statusbar.StatusBar
+import org.jetbrains.codeviewer.util.SplitterState
+import org.jetbrains.codeviewer.util.VerticalSplittable
+
+@Composable
+fun CodeViewerView(model: CodeViewer) {
+    val panelState = remember { PanelState() }
+
+    val animatedSize = if (panelState.splitter.isResizing) {
+        if (panelState.isExpanded) panelState.expandedSize else panelState.collapsedSize
+    } else {
+        animate(
+            if (panelState.isExpanded) panelState.expandedSize else panelState.collapsedSize,
+            SpringSpec(stiffness = StiffnessLow)
+        )
+    }
+
+    VerticalSplittable(
+        Modifier.fillMaxSize(),
+        panelState.splitter,
+        onResize = {
+            panelState.expandedSize =
+                (panelState.expandedSize + it).coerceAtLeast(panelState.expandedSizeMin)
+        }
+    ) {
+        ResizablePanel(Modifier.width(animatedSize).fillMaxHeight(), panelState) {
+            Column {
+                FileTreeViewTabView()
+                FileTreeView(model.fileTree)
+            }
+        }
+
+        Box {
+            if (model.editors.active != null) {
+                Column(Modifier.fillMaxSize()) {
+                    EditorTabsView(model.editors)
+                    Box(Modifier.weight(1f)) {
+                        EditorView(model.editors.active!!, model.settings)
+                    }
+                    StatusBar(model.settings)
+                }
+            } else {
+                EditorEmptyView()
+            }
+        }
+    }
+}
+
+private class PanelState {
+    val collapsedSize = 24.dp
+    var expandedSize by mutableStateOf(300.dp)
+    val expandedSizeMin = 90.dp
+    var isExpanded by mutableStateOf(true)
+    val splitter = SplitterState()
+}
+
+@Composable
+private fun ResizablePanel(
+    modifier: Modifier,
+    state: PanelState,
+    content: @Composable () -> Unit,
+) {
+    val alpha = animate(if (state.isExpanded) 1f else 0f, SpringSpec(stiffness = StiffnessLow))
+
+    Box(modifier) {
+        Box(Modifier.fillMaxSize().drawLayer(alpha = alpha)) {
+            content()
+        }
+
+        Icon(
+            if (state.isExpanded) Icons.Default.ArrowBack else Icons.Default.ArrowForward,
+            tint = AmbientContentColor.current,
+            modifier = Modifier
+                .padding(top = 4.dp)
+                .width(24.dp)
+                .clickable {
+                    state.isExpanded = !state.isExpanded
+                }
+                .padding(4.dp)
+                .align(Alignment.TopEnd)
+        )
+    }
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/ui/MainView.kt

@@ -0,0 +1,38 @@
+package org.jetbrains.codeviewer.ui
+
+import androidx.compose.material.MaterialTheme
+import androidx.compose.material.Surface
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import org.jetbrains.codeviewer.platform.HomeFolder
+import org.jetbrains.codeviewer.platform.PlatformTheme
+import org.jetbrains.codeviewer.platform.WithoutSelection
+import org.jetbrains.codeviewer.ui.common.AppTheme
+import org.jetbrains.codeviewer.ui.common.Settings
+import org.jetbrains.codeviewer.ui.editor.Editors
+import org.jetbrains.codeviewer.ui.filetree.FileTree
+
+@Composable
+fun MainView() {
+    val codeViewer = remember {
+        val editors = Editors()
+
+        CodeViewer(
+            editors = editors,
+            fileTree = FileTree(HomeFolder, editors),
+            settings = Settings()
+        )
+    }
+
+    WithoutSelection {
+        MaterialTheme(
+            colors = AppTheme.colors.material
+        ) {
+            PlatformTheme {
+                Surface {
+                    CodeViewerView(codeViewer)
+                }
+            }
+        }
+    }
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/ui/common/Fonts.kt

@@ -0,0 +1,64 @@
+package org.jetbrains.codeviewer.ui.common
+
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.font.fontFamily
+import org.jetbrains.codeviewer.platform.font
+
+object Fonts {
+    @Composable
+    fun jetbrainsMono() = fontFamily(
+        font(
+            "JetBrains Mono",
+            "jetbrainsmono_regular",
+            FontWeight.Normal,
+            FontStyle.Normal
+        ),
+        font(
+            "JetBrains Mono",
+            "jetbrainsmono_italic",
+            FontWeight.Normal,
+            FontStyle.Italic
+        ),
+
+        font(
+            "JetBrains Mono",
+            "jetbrainsmono_bold",
+            FontWeight.Bold,
+            FontStyle.Normal
+        ),
+        font(
+            "JetBrains Mono",
+            "jetbrainsmono_bold_italic",
+            FontWeight.Bold,
+            FontStyle.Italic
+        ),
+
+        font(
+            "JetBrains Mono",
+            "jetbrainsmono_extrabold",
+            FontWeight.ExtraBold,
+            FontStyle.Normal
+        ),
+        font(
+            "JetBrains Mono",
+            "jetbrainsmono_extrabold_italic",
+            FontWeight.ExtraBold,
+            FontStyle.Italic
+        ),
+
+        font(
+            "JetBrains Mono",
+            "jetbrainsmono_medium",
+            FontWeight.Medium,
+            FontStyle.Normal
+        ),
+        font(
+            "JetBrains Mono",
+            "jetbrainsmono_medium_italic",
+            FontWeight.Medium,
+            FontStyle.Italic
+        )
+    )
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/ui/common/Settings.kt

@@ -0,0 +1,11 @@
+package org.jetbrains.codeviewer.ui.common
+
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.unit.sp
+
+class Settings {
+    var fontSize by mutableStateOf(13.sp)
+    val maxLineSymbols = 120
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/ui/common/Theme.kt

@@ -0,0 +1,32 @@
+package org.jetbrains.codeviewer.ui.common
+
+import androidx.compose.material.darkColors
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.SpanStyle
+
+object AppTheme {
+    val colors: Colors = Colors()
+
+    val code: Code = Code()
+
+    class Colors(
+        val backgroundDark: Color = Color(0xFF2B2B2B),
+        val backgroundMedium: Color = Color(0xFF3C3F41),
+        val backgroundLight: Color = Color(0xFF4E5254),
+
+        val material: androidx.compose.material.Colors = darkColors(
+            background = backgroundDark,
+            surface = backgroundMedium,
+            primary = Color.White
+        ),
+    )
+
+    class Code(
+        val simple: SpanStyle = SpanStyle(Color(0xFFA9B7C6)),
+        val value: SpanStyle = SpanStyle(Color(0xFF6897BB)),
+        val keyword: SpanStyle = SpanStyle(Color(0xFFCC7832)),
+        val punctuation: SpanStyle = SpanStyle(Color(0xFFA1C17E)),
+        val annotation: SpanStyle = SpanStyle(Color(0xFFBBB529)),
+        val comment: SpanStyle = SpanStyle(Color(0xFF808080))
+    )
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/ui/editor/Editor.kt

@@ -0,0 +1,58 @@
+package org.jetbrains.codeviewer.ui.editor
+
+import androidx.compose.runtime.State
+import androidx.compose.runtime.mutableStateOf
+import kotlinx.coroutines.CoroutineScope
+import org.jetbrains.codeviewer.platform.File
+import org.jetbrains.codeviewer.util.SingleSelection
+import org.jetbrains.codeviewer.util.afterSet
+
+class Editor(
+    val fileName: String,
+    val lines: suspend (backgroundScope: CoroutineScope) -> Lines,
+) {
+    var close: (() -> Unit)? = null
+    lateinit var selection: SingleSelection
+
+    val isActive: Boolean
+        get() = selection.selected === this
+
+    fun activate() {
+        selection.selected = this
+    }
+
+    class Line(val number: Int, val content: Content)
+
+    interface Lines {
+        val lineNumberDigitCount: Int get() = size.toString().length
+        val size: Int
+        suspend fun get(index: Int): Line
+    }
+
+    class Content(val value: State<String>, val isCode: Boolean)
+}
+
+fun Editor(file: File) = Editor(
+    fileName = file.name
+) { backgroundScope ->
+    val textLines = file.readLines(backgroundScope)
+    val indexToEditedText = mutableMapOf<Int, String>()
+    val isCode = file.name.endsWith(".kt", ignoreCase = true)
+
+    suspend fun content(index: Int): Editor.Content {
+        val text = indexToEditedText[index] ?: textLines.get(index)
+        val state = mutableStateOf(text).afterSet {
+            indexToEditedText[index] = it
+        }
+        return Editor.Content(state, isCode)
+    }
+
+    object : Editor.Lines {
+        override val size get() = textLines.size
+
+        override suspend fun get(index: Int) = Editor.Line(
+            number = index + 1,
+            content = content(index)
+        )
+    }
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/ui/editor/EditorEmptyView.kt

@@ -0,0 +1,34 @@
+package org.jetbrains.codeviewer.ui.editor
+
+import androidx.compose.foundation.AmbientContentColor
+import androidx.compose.foundation.Text
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material.Icon
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Code
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+
+@Composable
+fun EditorEmptyView() = Box(Modifier.fillMaxSize()) {
+    Column(Modifier.align(Alignment.Center)) {
+        Icon(
+            Icons.Default.Code.copy(defaultWidth = 48.dp, defaultHeight = 48.dp),
+            tint = AmbientContentColor.current.copy(alpha = 0.60f),
+            modifier = Modifier.align(Alignment.CenterHorizontally)
+        )
+
+        Text(
+            "To view file open it from the file tree",
+            color = AmbientContentColor.current.copy(alpha = 0.60f),
+            fontSize = 20.sp,
+            modifier = Modifier.align(Alignment.CenterHorizontally).padding(16.dp)
+        )
+    }
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/ui/editor/EditorTabsView.kt

@@ -0,0 +1,72 @@
+package org.jetbrains.codeviewer.ui.editor
+
+import androidx.compose.animation.animate
+import androidx.compose.foundation.AmbientContentColor
+import androidx.compose.foundation.ScrollableRow
+import androidx.compose.foundation.Text
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.material.Icon
+import androidx.compose.material.Surface
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Close
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import org.jetbrains.codeviewer.ui.common.AppTheme
+
+@Composable
+fun EditorTabsView(model: Editors) = ScrollableRow {
+    for (editor in model.editors) {
+        EditorTabView(editor)
+    }
+}
+
+@Composable
+fun EditorTabView(model: Editor) = Surface(
+    color = animate(if (model.isActive) {
+        AppTheme.colors.backgroundDark
+    } else {
+        Color.Transparent
+    })
+) {
+    Row(
+        Modifier
+            .clickable {
+                model.activate()
+            }
+            .padding(4.dp),
+        verticalAlignment = Alignment.CenterVertically
+    ) {
+        Text(
+            model.fileName,
+            color = AmbientContentColor.current,
+            fontSize = 12.sp,
+            modifier = Modifier.padding(horizontal = 4.dp)
+        )
+
+        val close = model.close
+
+        if (close != null) {
+            Icon(
+                Icons.Default.Close, tint = AmbientContentColor.current, modifier = Modifier
+                .size(24.dp)
+                .padding(4.dp)
+                .clickable {
+                    close()
+                })
+        } else {
+            Box(
+                modifier = Modifier
+                    .size(24.dp, 24.dp)
+                    .padding(4.dp)
+            )
+        }
+    }
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/ui/editor/EditorView.kt

@@ -0,0 +1,191 @@
+package org.jetbrains.codeviewer.ui.editor
+
+import androidx.compose.foundation.AmbientContentColor
+import androidx.compose.foundation.Text
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.material.CircularProgressIndicator
+import androidx.compose.material.Surface
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.drawOpacity
+import androidx.compose.ui.platform.DensityAmbient
+import androidx.compose.ui.text.AnnotatedString
+import androidx.compose.ui.text.SpanStyle
+import androidx.compose.ui.text.annotatedString
+import androidx.compose.ui.text.withStyle
+import androidx.compose.ui.unit.dp
+import org.jetbrains.codeviewer.platform.SelectionContainer
+import org.jetbrains.codeviewer.platform.VerticalScrollbar
+import org.jetbrains.codeviewer.platform.WithoutSelection
+import org.jetbrains.codeviewer.ui.common.AppTheme
+import org.jetbrains.codeviewer.ui.common.Fonts
+import org.jetbrains.codeviewer.ui.common.Settings
+import org.jetbrains.codeviewer.util.LazyColumnFor
+import org.jetbrains.codeviewer.util.loadable
+import org.jetbrains.codeviewer.util.loadableScoped
+import org.jetbrains.codeviewer.util.withoutWidthConstraints
+import kotlin.text.Regex.Companion.fromLiteral
+
+@Composable
+fun EditorView(model: Editor, settings: Settings) = key(model) {
+    with (DensityAmbient.current) {
+        SelectionContainer {
+            Surface(
+                Modifier.fillMaxSize(),
+                color = AppTheme.colors.backgroundDark,
+            ) {
+                val lines by loadableScoped(model.lines)
+
+                if (lines != null) {
+                    Box {
+                        Lines(lines!!, settings)
+                        Box(
+                            Modifier
+                                .offset(
+                                    x = settings.fontSize.toDp() * 0.5f * settings.maxLineSymbols
+                                )
+                                .width(1.dp)
+                                .fillMaxHeight()
+                                .background(AppTheme.colors.backgroundLight)
+                        )
+                    }
+                } else {
+                    CircularProgressIndicator(
+                        modifier = Modifier
+                            .size(36.dp)
+                            .padding(4.dp)
+                    )
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun Lines(lines: Editor.Lines, settings: Settings) = with(DensityAmbient.current) {
+    val maxNum = remember(lines.lineNumberDigitCount) {
+        (1..lines.lineNumberDigitCount).joinToString(separator = "") { "9" }
+    }
+
+    Box(Modifier.fillMaxSize()) {
+        val scrollState = rememberLazyListState()
+        val lineHeight = settings.fontSize.toDp() * 1.6f
+
+        LazyColumnFor(
+            lines.size,
+            modifier = Modifier.fillMaxSize(),
+            state = scrollState,
+            itemContent = { index ->
+                val line: Editor.Line? by loadable { lines.get(index) }
+                Box(Modifier.height(lineHeight)) {
+                    if (line != null) {
+                        Line(Modifier.align(Alignment.CenterStart), maxNum, line!!, settings)
+                    }
+                }
+            }
+        )
+
+        VerticalScrollbar(
+            Modifier.align(Alignment.CenterEnd),
+            scrollState,
+            lines.size,
+            lineHeight
+        )
+    }
+}
+
+// Поддержка русского языка
+// دعم اللغة العربية
+// 中文支持
+@Composable
+private fun Line(modifier: Modifier, maxNum: String, line: Editor.Line, settings: Settings) {
+    Row(modifier = modifier) {
+        WithoutSelection {
+            Box {
+                LineNumber(maxNum, Modifier.drawOpacity(0f), settings)
+                LineNumber(line.number.toString(), Modifier.align(Alignment.CenterEnd), settings)
+            }
+        }
+        LineContent(
+            line.content,
+            modifier = Modifier
+                .weight(1f)
+                .withoutWidthConstraints()
+                .padding(start = 28.dp, end = 12.dp),
+            settings = settings
+        )
+    }
+}
+
+@Composable
+private fun LineNumber(number: String, modifier: Modifier, settings: Settings) = Text(
+    text = number,
+    fontSize = settings.fontSize,
+    fontFamily = Fonts.jetbrainsMono(),
+    color = AmbientContentColor.current.copy(alpha = 0.30f),
+    modifier = modifier.padding(start = 12.dp)
+)
+
+@Composable
+private fun LineContent(content: Editor.Content, modifier: Modifier, settings: Settings) = Text(
+    text = if (content.isCode) {
+        codeString(content.value.value)
+    } else {
+        annotatedString {
+            withStyle(AppTheme.code.simple) {
+                append(content.value.value)
+            }
+        }
+    },
+    fontSize = settings.fontSize,
+    fontFamily = Fonts.jetbrainsMono(),
+    modifier = modifier,
+    softWrap = false
+)
+
+private fun codeString(str: String) = annotatedString {
+    withStyle(AppTheme.code.simple) {
+        append(str.replace("\t", "    "))
+        addStyle(AppTheme.code.punctuation, ":")
+        addStyle(AppTheme.code.punctuation, "=")
+        addStyle(AppTheme.code.punctuation, "\"")
+        addStyle(AppTheme.code.punctuation, "[")
+        addStyle(AppTheme.code.punctuation, "]")
+        addStyle(AppTheme.code.punctuation, "{")
+        addStyle(AppTheme.code.punctuation, "}")
+        addStyle(AppTheme.code.punctuation, "(")
+        addStyle(AppTheme.code.punctuation, ")")
+        addStyle(AppTheme.code.punctuation, ",")
+        addStyle(AppTheme.code.keyword, "fun ")
+        addStyle(AppTheme.code.keyword, "val ")
+        addStyle(AppTheme.code.keyword, "var ")
+        addStyle(AppTheme.code.keyword, "private ")
+        addStyle(AppTheme.code.keyword, "internal ")
+        addStyle(AppTheme.code.keyword, "for ")
+        addStyle(AppTheme.code.keyword, "expect ")
+        addStyle(AppTheme.code.keyword, "actual ")
+        addStyle(AppTheme.code.keyword, "import ")
+        addStyle(AppTheme.code.keyword, "package ")
+        addStyle(AppTheme.code.value, "true")
+        addStyle(AppTheme.code.value, "false")
+        addStyle(AppTheme.code.value, Regex("[0-9]*"))
+        addStyle(AppTheme.code.annotation, Regex("^@[a-zA-Z_]*"))
+        addStyle(AppTheme.code.comment, Regex("^\\s*//.*"))
+    }
+}
+
+private fun AnnotatedString.Builder.addStyle(style: SpanStyle, regexp: String) {
+    addStyle(style, fromLiteral(regexp))
+}
+
+private fun AnnotatedString.Builder.addStyle(style: SpanStyle, regexp: Regex) {
+    for (result in regexp.findAll(toString())) {
+        addStyle(style, result.range.first, result.range.last + 1)
+    }
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/ui/editor/Editors.kt

@@ -0,0 +1,32 @@
+package org.jetbrains.codeviewer.ui.editor
+
+import androidx.compose.runtime.mutableStateListOf
+import org.jetbrains.codeviewer.platform.File
+import org.jetbrains.codeviewer.util.SingleSelection
+
+class Editors {
+    private val selection = SingleSelection()
+
+    var editors = mutableStateListOf<Editor>()
+        private set
+
+    val active: Editor? get() = selection.selected as Editor?
+
+    fun open(file: File) {
+        val editor = Editor(file)
+        editor.selection = selection
+        editor.close = {
+            close(editor)
+        }
+        editors.add(editor)
+        editor.activate()
+    }
+
+    private fun close(editor: Editor) {
+        val index = editors.indexOf(editor)
+        editors.remove(editor)
+        if (editor.isActive) {
+            selection.selected = editors.getOrNull(index.coerceAtMost(editors.lastIndex))
+        }
+    }
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/ui/filetree/FileTree.kt

@@ -0,0 +1,72 @@
+package org.jetbrains.codeviewer.ui.filetree
+
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import org.jetbrains.codeviewer.platform.File
+import org.jetbrains.codeviewer.ui.editor.Editors
+
+class ExpandableFile(
+    val file: File,
+    val level: Int,
+) {
+    var children: List<ExpandableFile> by mutableStateOf(emptyList())
+    val canExpand: Boolean get() = file.hasChildren
+
+    fun toggleExpanded() {
+        children = if (children.isEmpty()) {
+            file.children
+                .map { ExpandableFile(it, level + 1) }
+                .sortedWith(compareBy({ it.file.isDirectory }, { it.file.name }))
+                .sortedBy { !it.file.isDirectory }
+        } else {
+            emptyList()
+        }
+    }
+}
+
+class FileTree(root: File, private val editors: Editors) {
+    private val expandableRoot = ExpandableFile(root, 0).apply {
+        toggleExpanded()
+    }
+
+    val items: List<Item> get() = expandableRoot.toItems()
+
+    inner class Item constructor(
+        private val file: ExpandableFile
+    ) {
+        val name: String get() = file.file.name
+
+        val level: Int get() = file.level
+
+        val type: ItemType
+            get() = if (file.file.isDirectory) {
+                ItemType.Folder(isExpanded = file.children.isNotEmpty(), canExpand = file.canExpand)
+            } else {
+                ItemType.File(ext = file.file.name.substringAfterLast(".").toLowerCase())
+            }
+
+        fun open() = when (type) {
+            is ItemType.Folder -> file.toggleExpanded()
+            is ItemType.File -> editors.open(file.file)
+        }
+    }
+
+    sealed class ItemType {
+        class Folder(val isExpanded: Boolean, val canExpand: Boolean) : ItemType()
+        class File(val ext: String) : ItemType()
+    }
+
+    private fun ExpandableFile.toItems(): List<Item> {
+        fun ExpandableFile.addTo(list: MutableList<Item>) {
+            list.add(Item(this))
+            for (child in children) {
+                child.addTo(list)
+            }
+        }
+
+        val list = mutableListOf<Item>()
+        addTo(list)
+        return list
+    }
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/ui/filetree/FileTreeView.kt

@@ -0,0 +1,128 @@
+package org.jetbrains.codeviewer.ui.filetree
+
+import androidx.compose.foundation.AmbientContentColor
+import androidx.compose.foundation.Text
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.lazy.LazyColumnFor
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.material.Icon
+import androidx.compose.material.Surface
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.*
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clipToBounds
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.DensityAmbient
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.TextUnit
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import org.jetbrains.codeviewer.platform.VerticalScrollbar
+import org.jetbrains.codeviewer.platform.pointerMoveFilter
+import org.jetbrains.codeviewer.util.withoutWidthConstraints
+
+@Composable
+fun FileTreeViewTabView() = Surface {
+    Row(
+        Modifier.padding(8.dp),
+        verticalAlignment = Alignment.CenterVertically
+    ) {
+        Text(
+            "Files",
+            color = AmbientContentColor.current.copy(alpha = 0.60f),
+            fontSize = 12.sp,
+            modifier = Modifier.padding(horizontal = 4.dp)
+        )
+    }
+}
+
+@Composable
+fun FileTreeView(model: FileTree) = Surface(
+    modifier = Modifier.fillMaxSize()
+) {
+    with(DensityAmbient.current) {
+        Box {
+            val scrollState = rememberLazyListState()
+            val fontSize = 14.sp
+            val lineHeight = fontSize.toDp() * 1.5f
+
+            LazyColumnFor(
+                model.items,
+                modifier = Modifier.fillMaxSize().withoutWidthConstraints(),
+                state = scrollState,
+                itemContent = { FileTreeItemView(fontSize, lineHeight, it) }
+            )
+
+            VerticalScrollbar(
+                Modifier.align(Alignment.CenterEnd),
+                scrollState,
+                model.items.size,
+                lineHeight
+            )
+        }
+    }
+}
+
+@Composable
+private fun FileTreeItemView(fontSize: TextUnit, height: Dp, model: FileTree.Item) = Row(
+    modifier = Modifier
+        .wrapContentHeight()
+        .clickable { model.open() }
+        .padding(start = 24.dp * model.level)
+        .height(height)
+        .fillMaxWidth()
+) {
+    val active = remember { mutableStateOf(false) }
+
+    FileItemIcon(Modifier.align(Alignment.CenterVertically), model)
+    Text(
+        text = model.name,
+        color = if (active.value) AmbientContentColor.current.copy(alpha = 0.60f) else AmbientContentColor.current,
+        modifier = Modifier
+            .align(Alignment.CenterVertically)
+            .clipToBounds()
+            .pointerMoveFilter(
+                onEnter = {
+                    active.value = true
+                    true
+                },
+                onExit = {
+                    active.value = false
+                    true
+                }
+            ),
+        softWrap = true,
+        fontSize = fontSize,
+        overflow = TextOverflow.Ellipsis,
+        maxLines = 1
+    )
+}
+
+@Composable
+private fun FileItemIcon(modifier: Modifier, model: FileTree.Item) = Box(modifier.size(24.dp).padding(4.dp)) {
+    when (val type = model.type) {
+        is FileTree.ItemType.Folder -> when {
+            !type.canExpand -> Unit
+            type.isExpanded -> Icon(Icons.Default.KeyboardArrowDown, tint = AmbientContentColor.current)
+            else -> Icon(Icons.Default.KeyboardArrowRight, tint = AmbientContentColor.current)
+        }
+        is FileTree.ItemType.File -> when (type.ext) {
+            "kt" -> Icon(Icons.Default.Code, tint = Color(0xFF3E86A0))
+            "xml" -> Icon(Icons.Default.Code, tint = Color(0xFFC19C5F))
+            "txt" -> Icon(Icons.Default.Description, tint = Color(0xFF87939A))
+            "md" -> Icon(Icons.Default.Description, tint = Color(0xFF87939A))
+            "gitignore" -> Icon(Icons.Default.BrokenImage, tint = Color(0xFF87939A))
+            "gradle" -> Icon(Icons.Default.Build, tint = Color(0xFF87939A))
+            "kts" -> Icon(Icons.Default.Build, tint = Color(0xFF3E86A0))
+            "properties" -> Icon(Icons.Default.Settings, tint = Color(0xFF62B543))
+            "bat" -> Icon(Icons.Default.Launch, tint = Color(0xFF87939A))
+            else -> Icon(Icons.Default.TextSnippet, tint = Color(0xFF87939A))
+        }
+    }
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/ui/statusbar/StatusBar.kt

@@ -0,0 +1,48 @@
+package org.jetbrains.codeviewer.ui.statusbar
+
+import androidx.compose.foundation.AmbientContentColor
+import androidx.compose.foundation.Text
+import androidx.compose.foundation.layout.*
+import androidx.compose.material.Slider
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Providers
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.DensityAmbient
+import androidx.compose.ui.unit.Density
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.lerp
+import androidx.compose.ui.unit.sp
+import org.jetbrains.codeviewer.ui.common.Settings
+
+private val MinFontSize = 6.sp
+private val MaxFontSize = 40.sp
+
+@Composable
+fun StatusBar(settings: Settings) = Box(
+    Modifier
+        .height(32.dp)
+        .fillMaxWidth()
+        .padding(4.dp)
+) {
+    Row(Modifier.fillMaxHeight().align(Alignment.CenterEnd)) {
+        Text(
+            text = "Text size",
+            modifier = Modifier.align(Alignment.CenterVertically),
+            color = AmbientContentColor.current.copy(alpha = 0.60f),
+            fontSize = 12.sp
+        )
+
+        Spacer(Modifier.width(8.dp))
+
+        Providers(DensityAmbient provides DensityAmbient.current.scale(0.5f)) {
+            Slider(
+                (settings.fontSize - MinFontSize) / (MaxFontSize - MinFontSize),
+                onValueChange = { settings.fontSize = lerp(MinFontSize, MaxFontSize, it) },
+                modifier = Modifier.width(240.dp).align(Alignment.CenterVertically)
+            )
+        }
+    }
+}
+
+private fun Density.scale(scale: Float) = Density(density * scale, fontScale * scale)

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/util/LayoutModifiers.kt

@@ -0,0 +1,11 @@
+package org.jetbrains.codeviewer.util
+
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.layout
+
+fun Modifier.withoutWidthConstraints() = layout { measurable, constraints ->
+    val placeable = measurable.measure(constraints.copy(maxWidth = Int.MAX_VALUE))
+    layout(constraints.maxWidth, placeable.height) {
+        placeable.place(0, 0)
+    }
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/util/LazyColumnFor.kt

@@ -0,0 +1,33 @@
+package org.jetbrains.codeviewer.util
+
+import androidx.compose.foundation.layout.PaddingValues
+import androidx.compose.foundation.lazy.LazyColumnForIndexed
+import androidx.compose.foundation.lazy.LazyItemScope
+import androidx.compose.foundation.lazy.LazyListState
+import androidx.compose.foundation.lazy.rememberLazyListState
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+
+@Composable
+fun LazyColumnFor(
+    size: Int,
+    modifier: Modifier = Modifier,
+    state: LazyListState = rememberLazyListState(),
+    contentPadding: PaddingValues = PaddingValues(0.dp),
+    horizontalGravity: Alignment.Horizontal = Alignment.Start,
+    itemContent: @Composable LazyItemScope.(index: Int) -> Unit
+) = LazyColumnForIndexed(
+    UnitList(size),
+    modifier,
+    state,
+    contentPadding,
+    horizontalGravity,
+) { index, _ ->
+    itemContent(index)
+}
+
+private class UnitList(override val size: Int) : AbstractList<Unit>() {
+    override fun get(index: Int) = Unit
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/util/Loadable.kt

@@ -0,0 +1,25 @@
+package org.jetbrains.codeviewer.util
+
+import androidx.compose.runtime.*
+import kotlinx.coroutines.CancellationException
+import kotlinx.coroutines.CoroutineScope
+
+@Composable
+fun <T : Any> loadable(load: suspend () -> T): MutableState<T?> {
+    return loadableScoped { load() }
+}
+
+@Composable
+fun <T : Any> loadableScoped(load: suspend CoroutineScope.() -> T): MutableState<T?> {
+    val state: MutableState<T?> = remember { mutableStateOf(null) }
+    LaunchedTask {
+        try {
+            state.value = load()
+        } catch (e: CancellationException) {
+            // ignore
+        } catch (e: Exception) {
+            e.printStackTrace()
+        }
+    }
+    return state
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/util/SingleSelection.kt

@@ -0,0 +1,9 @@
+package org.jetbrains.codeviewer.util
+
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+
+class SingleSelection {
+    var selected: Any? by mutableStateOf(null)
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/util/State.kt

@@ -0,0 +1,14 @@
+package org.jetbrains.codeviewer.util
+
+import androidx.compose.runtime.MutableState
+
+fun <T> MutableState<T>.afterSet(
+    action: (T) -> Unit
+) = object : MutableState<T> by this {
+    override var value: T
+        get() = this@afterSet.value
+        set(value) {
+            this@afterSet.value = value
+            action(value)
+        }
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/util/TextLines.kt

@@ -0,0 +1,6 @@
+package org.jetbrains.codeviewer.util
+
+interface TextLines {
+    val size: Int
+    suspend fun get(index: Int): String
+}

examples/codeviewer/common/src/commonMain/kotlin/org/jetbrains/codeviewer/util/VerticalSplittable.kt

@@ -0,0 +1,91 @@
+package org.jetbrains.codeviewer.util
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.gestures.draggable
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.layout.width
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Layout
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.gesture.scrollorientationlocking.Orientation
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.Constraints
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import org.jetbrains.codeviewer.platform.cursorForHorizontalResize
+import org.jetbrains.codeviewer.ui.common.AppTheme
+
+@Composable
+fun VerticalSplittable(
+    modifier: Modifier,
+    splitterState: SplitterState,
+    onResize: (delta: Dp) -> Unit,
+    children: @Composable () -> Unit
+) = Layout({
+    children()
+    VerticalSplitter(splitterState, onResize)
+}, modifier, measureBlock = { measurables, constraints ->
+    require(measurables.size == 3)
+
+    val firstPlaceable = measurables[0].measure(constraints.copy(minWidth = 0))
+    val secondWidth = constraints.maxWidth - firstPlaceable.width
+    val secondPlaceable = measurables[1].measure(
+        Constraints(
+            minWidth = secondWidth,
+            maxWidth = secondWidth,
+            minHeight = constraints.maxHeight,
+            maxHeight = constraints.maxHeight
+        )
+    )
+    val splitterPlaceable = measurables[2].measure(constraints)
+    layout(constraints.maxWidth, constraints.maxHeight) {
+        firstPlaceable.place(0, 0)
+        secondPlaceable.place(firstPlaceable.width, 0)
+        splitterPlaceable.place(firstPlaceable.width, 0)
+    }
+})
+
+class SplitterState {
+    var isResizing by mutableStateOf(false)
+    var isResizeEnabled by mutableStateOf(true)
+}
+
+@Composable
+fun VerticalSplitter(
+    splitterState: SplitterState,
+    onResize: (delta: Dp) -> Unit,
+    color: Color = AppTheme.colors.backgroundDark
+) = Box {
+    Box(
+        Modifier
+            .width(8.dp)
+            .fillMaxHeight()
+            .run {
+                if (splitterState.isResizeEnabled) {
+                    this.
+                        draggable(
+                            Orientation.Horizontal,
+                            startDragImmediately = true,
+                            onDragStarted = { splitterState.isResizing = true },
+                            onDragStopped = { splitterState.isResizing = false }
+                        ) {
+                            onResize(it.toDp())
+                        }
+                        .cursorForHorizontalResize()
+                } else {
+                    this
+                }
+            }
+    )
+
+    Box(
+        Modifier
+            .width(1.dp)
+            .fillMaxHeight()
+            .background(color)
+    )
+}

examples/codeviewer/common/src/desktopMain/kotlin/org/jetbrains/codeviewer/platform/File.kt

@@ -0,0 +1,5 @@
+@file:Suppress("NewApi")
+
+package org.jetbrains.codeviewer.platform
+
+actual val HomeFolder: File get() = java.io.File(System.getProperty("user.home")).toProjectFile()

examples/codeviewer/common/src/desktopMain/kotlin/org/jetbrains/codeviewer/platform/Mouse.kt

@@ -0,0 +1,33 @@
+package org.jetbrains.codeviewer.platform
+
+import androidx.compose.desktop.AppWindowAmbient
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.composed
+import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.input.pointer.pointerMoveFilter
+import java.awt.Cursor
+
+actual fun Modifier.pointerMoveFilter(
+    onEnter: () -> Boolean,
+    onExit: () -> Boolean,
+    onMove: (Offset) -> Boolean
+): Modifier = this.pointerMoveFilter(onEnter = onEnter, onExit = onExit, onMove = onMove)
+
+actual fun Modifier.cursorForHorizontalResize(): Modifier = composed {
+    var isHover by remember { mutableStateOf(false) }
+
+    if (isHover) {
+        AppWindowAmbient.current!!.window.cursor = Cursor(Cursor.E_RESIZE_CURSOR)
+    } else {
+        AppWindowAmbient.current!!.window.cursor = Cursor.getDefaultCursor()
+    }
+
+    pointerMoveFilter(
+        onEnter = { isHover = true; true },
+        onExit = { isHover = false; true }
+    )
+}

examples/codeviewer/common/src/desktopMain/kotlin/org/jetbrains/codeviewer/platform/Resources.kt

@@ -0,0 +1,25 @@
+package org.jetbrains.codeviewer.platform
+
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.graphics.ImageAsset
+import androidx.compose.ui.graphics.asImageAsset
+import androidx.compose.ui.text.font.Font
+import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.text.font.FontWeight
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import org.jetbrains.skija.Image
+import java.io.InputStream
+import java.net.URL
+
+@Composable
+actual fun imageResource(res: String) = androidx.compose.ui.res.imageResource("drawable/$res.png")
+
+actual suspend fun imageFromUrl(url: String): ImageAsset = withContext(Dispatchers.IO) {
+    val bytes = URL(url).openStream().buffered().use(InputStream::readBytes)
+    Image.makeFromEncoded(bytes).asImageAsset()
+}
+
+@Composable
+actual fun font(name: String, res: String, weight: FontWeight, style: FontStyle): Font =
+       androidx.compose.ui.text.platform.font(name, "font/$res.ttf", weight, style)

examples/codeviewer/common/src/desktopMain/kotlin/org/jetbrains/codeviewer/platform/Scrollbar.kt

@@ -0,0 +1,48 @@
+package org.jetbrains.codeviewer.platform
+
+import androidx.compose.foundation.ExperimentalFoundationApi
+import androidx.compose.foundation.LazyScrollbarAdapter
+import androidx.compose.foundation.ScrollState
+import androidx.compose.foundation.lazy.LazyListState
+import androidx.compose.foundation.rememberScrollbarAdapter
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.DensityAmbient
+import androidx.compose.ui.unit.Dp
+
+@Composable
+actual fun VerticalScrollbar(
+    modifier: Modifier,
+    scrollState: ScrollState
+) = androidx.compose.foundation.VerticalScrollbar(
+    modifier,
+    adapter = rememberScrollbarAdapter(scrollState)
+)
+
+@OptIn(ExperimentalFoundationApi::class)
+@Composable
+actual fun VerticalScrollbar(
+    modifier: Modifier,
+    scrollState: LazyListState,
+    itemCount: Int,
+    averageItemSize: Dp
+) = androidx.compose.foundation.VerticalScrollbar(
+    modifier,
+    adapter = rememberScrollbarAdapterFixed(scrollState, itemCount, averageItemSize)
+)
+
+// TODO/migrateToMaster should be fixed in androidx-master-dev
+@Composable
+fun rememberScrollbarAdapterFixed(
+    scrollState: LazyListState,
+    itemCount: Int,
+    averageItemSize: Dp
+): LazyScrollbarAdapter {
+    val density = DensityAmbient.current
+    return remember(density, scrollState, itemCount, averageItemSize) {
+        with(density) {
+            LazyScrollbarAdapter(scrollState, itemCount, averageItemSize.toPx())
+        }
+    }
+}

examples/codeviewer/common/src/desktopMain/kotlin/org/jetbrains/codeviewer/platform/Selection.kt

@@ -0,0 +1,26 @@
+package org.jetbrains.codeviewer.platform
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.platform.DesktopSelectionContainer
+import androidx.compose.ui.selection.Selection
+
+@Composable
+actual fun SelectionContainer(children: @Composable () -> Unit) {
+    val selection = remember { mutableStateOf<Selection?>(null) }
+    DesktopSelectionContainer(
+        selection = selection.value,
+        onSelectionChange = { selection.value = it },
+        children = children
+    )
+}
+
+@Composable
+actual fun WithoutSelection(children: @Composable () -> Unit) {
+    androidx.compose.ui.selection.SelectionContainer(
+        selection = null,
+        onSelectionChange = {},
+        children = children
+    )
+}

examples/codeviewer/common/src/desktopMain/kotlin/org/jetbrains/codeviewer/platform/Theme.kt

@@ -0,0 +1,7 @@
+package org.jetbrains.codeviewer.platform
+
+import androidx.compose.desktop.DesktopTheme
+import androidx.compose.runtime.Composable
+
+@Composable
+actual fun PlatformTheme(content: @Composable () -> Unit) = DesktopTheme(content = content)

examples/codeviewer/common/src/jvmMain/kotlin/org/jetbrains/codeviewer/platform/JvmFile.kt

@@ -0,0 +1,145 @@
+package org.jetbrains.codeviewer.platform
+
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.setValue
+import kotlinx.coroutines.*
+import org.jetbrains.codeviewer.util.TextLines
+import java.io.FileInputStream
+import java.io.IOException
+import java.io.RandomAccessFile
+import java.nio.channels.FileChannel
+
+fun java.io.File.toProjectFile(): File = object : File {
+    override val name: String get() = this@toProjectFile.name
+
+    override val isDirectory: Boolean get() = this@toProjectFile.isDirectory
+
+    override val children: List<File>
+        get() = this@toProjectFile
+            .listFiles()
+            .orEmpty()
+            .map { it.toProjectFile() }
+
+    override val hasChildren: Boolean
+        get() = isDirectory && listFiles()?.size ?: 0 > 0
+
+    override suspend fun readLines(backgroundScope: CoroutineScope): TextLines {
+        // linePositions can be very big, so we are using IntList instead of List<Long>
+        val linePositions = IntList()
+        var size by mutableStateOf(0)
+
+        val refreshJob = backgroundScope.launch {
+            delay(100)
+            size = linePositions.size
+            while (true) {
+                delay(1000)
+                size = linePositions.size
+            }
+        }
+
+        backgroundScope.launch {
+            readLinePositions(linePositions)
+            refreshJob.cancel()
+            size = linePositions.size
+        }
+
+        return object : TextLines {
+            override val size get() = size
+
+            override suspend fun get(index: Int): String {
+                return withContext(Dispatchers.IO) {
+                    val position = linePositions[index]
+                    try {
+                        RandomAccessFile(this@toProjectFile, "rws").use {
+                            it.seek(position.toLong())
+                            // NOTE: it isn't efficient, but simple
+                            String(
+                                it.readLine()
+                                    .toCharArray()
+                                    .map(Char::toByte)
+                                    .toByteArray(),
+                                Charsets.UTF_8
+                            )
+                        }
+                    } catch (e: IOException) {
+                        e.printStackTrace()
+                        "<Error on opening the file>"
+                    }
+                }
+            }
+        }
+    }
+}
+
+@Suppress("BlockingMethodInNonBlockingContext")
+private suspend fun java.io.File.readLinePositions(list: IntList) = withContext(Dispatchers.IO) {
+    require(length() <= Int.MAX_VALUE) {
+        "Files with size over ${Int.MAX_VALUE} aren't supported"
+    }
+
+    val averageLineLength = 200
+    list.clear(length().toInt() / averageLineLength)
+
+    var isBeginOfLine = true
+    var position = 0L
+
+    try {
+        FileInputStream(this@readLinePositions).use {
+            val channel = it.channel
+            val ib = channel.map(
+                FileChannel.MapMode.READ_ONLY, 0, channel.size()
+            )
+            while (ib.hasRemaining()) {
+                val byte = ib.get()
+                if (isBeginOfLine) {
+                    list.add(position.toInt())
+                }
+                isBeginOfLine = byte.toChar() == '\n'
+                position++
+            }
+        }
+    } catch (e: IOException) {
+        e.printStackTrace()
+        list.clear(1)
+        list.add(0)
+    }
+
+    list.compact()
+}
+
+/**
+ * Compact version of List<Int> (without unboxing Int and using IntArray under the hood)
+ */
+private class IntList(initialCapacity: Int = 16) {
+    @Volatile
+    private var array = IntArray(initialCapacity)
+
+    @Volatile
+    var size: Int = 0
+        private set
+
+    fun clear(capacity: Int) {
+        array = IntArray(capacity)
+        size = 0
+    }
+
+    fun add(value: Int) {
+        if (size == array.size) {
+            doubleCapacity()
+        }
+        array[size++] = value
+    }
+
+    operator fun get(index: Int) = array[index]
+
+    private fun doubleCapacity() {
+        val newArray = IntArray(array.size * 2 + 1)
+        System.arraycopy(array, 0, newArray, 0, size)
+        array = newArray
+    }
+
+    fun compact() {
+        array = array.copyOfRange(0, size)
+    }
+}

examples/codeviewer/desktop/build.gradle.kts

@@ -0,0 +1,27 @@
+import org.jetbrains.compose.compose
+
+plugins {
+    kotlin("multiplatform") // kotlin("jvm") doesn't work well in IDEA/AndroidStudio (https://github.com/JetBrains/compose-jb/issues/22)
+    id("org.jetbrains.compose")
+    java
+    application
+}
+
+kotlin {
+    jvm {
+        withJava()
+    }
+
+    sourceSets {
+        named("jvmMain") {
+            dependencies {
+                implementation(compose.desktop.all)
+                implementation(project(":common"))
+            }
+        }
+    }
+}
+
+application {
+    mainClassName = "org.jetbrains.codeviewer.MainKt"
+}

examples/codeviewer/desktop/src/jvmMain/kotlin/org/jetbrains/codeviewer/main.kt

@@ -0,0 +1,24 @@
+package org.jetbrains.codeviewer
+
+import androidx.compose.desktop.Window
+import androidx.compose.foundation.layout.ExperimentalLayout
+import androidx.compose.ui.unit.IntSize
+import org.jetbrains.codeviewer.ui.MainView
+import java.awt.image.BufferedImage
+import javax.imageio.ImageIO
+
+@OptIn(ExperimentalLayout::class)
+fun main() = Window(
+    title = "Code Viewer",
+    size = IntSize(1280, 768),
+    icon = loadImageResource("ic_launcher.png")
+) {
+    MainView()
+}
+
+@Suppress("SameParameterValue")
+private fun loadImageResource(path: String): BufferedImage {
+    val resource = Thread.currentThread().contextClassLoader.getResource(path)
+    requireNotNull(resource) { "Resource $path not found" }
+    return resource.openStream().use(ImageIO::read)
+}

examples/codeviewer/gradle.properties

@@ -0,0 +1,21 @@
+# Project-wide Gradle settings.
+# IDE (e.g. Android Studio) users:
+# Gradle settings configured through the IDE *will override*
+# any settings specified in this file.
+# For more details on how to configure your build environment visit
+# http://www.gradle.org/docs/current/userguide/build_environment.html
+# Specifies the JVM arguments used for the daemon process.
+# The setting is particularly useful for tweaking memory settings.
+org.gradle.jvmargs=-Xmx2048m
+# When configured, Gradle will run in incubating parallel mode.
+# This option should only be used with decoupled projects. More details, visit
+# http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects
+# org.gradle.parallel=true
+# AndroidX package structure to make it clearer which packages are bundled with the
+# Android operating system, and which are packaged with your app"s APK
+# https://developer.android.com/topic/libraries/support-library/androidx-rn
+android.useAndroidX=true
+# Automatically convert third-party libraries to use AndroidX
+android.enableJetifier=true
+# Kotlin code style for this project: "official" or "obsolete":
+kotlin.code.style=official

examples/codeviewer/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.5.1-all.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

examples/codeviewer/gradlew

@@ -0,0 +1,183 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=`expr $i + 1`
+    done
+    case $i in
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=`save "$@"`
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+exec "$JAVACMD" "$@"

examples/codeviewer/gradlew.bat

@@ -0,0 +1,100 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

examples/codeviewer/settings.gradle.kts

@@ -0,0 +1 @@
+include(":common", ":android", ":desktop")