Split pane. Refactoring (#408)

components/.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

components/SplitPane/common/build.gradle.kts

@@ -1,4 +1,5 @@
 import org.jetbrains.compose.compose
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 plugins {
     kotlin("multiplatform")
@@ -19,3 +20,8 @@ kotlin {
         named("desktopMain") {}
     }
 }
+
+// TODO it seems that argument isn't applied to the common sourceSet. Figure out why
+tasks.withType<KotlinCompile>().configureEach {
+    kotlinOptions.freeCompilerArgs += "-Xopt-in=kotlin.RequiresOptIn"
+}

components/SplitPane/common/src/commonMain/kotlin/org/jetbrains/compose/splitpane/ExperimentalSplitPaneApi.kt

@@ -0,0 +1,6 @@
+package org.jetbrains.compose.splitpane
+
+@MustBeDocumented
+@Retention(value = AnnotationRetention.BINARY)
+@RequiresOptIn(level = RequiresOptIn.Level.WARNING)
+annotation class ExperimentalSplitPaneApi

components/SplitPane/common/src/commonMain/kotlin/org/jetbrains/compose/splitpane/SplitPane.kt

@@ -20,6 +20,7 @@ internal data class MinimalSizes(
  * @param content a block which describes the content. Inside this block you can use methods like
  * [SplitPaneScope.first], [SplitPaneScope.second], to describe parts of split pane.
  */
+@ExperimentalSplitPaneApi
 @Composable
 fun VerticalSplitPane(
     modifier: Modifier = Modifier,
@@ -54,6 +55,7 @@ fun VerticalSplitPane(
  * @param content a block which describes the content. Inside this block you can use methods like
  * [SplitPaneScope.first], [SplitPaneScope.second], to describe parts of split pane.
  */
+@ExperimentalSplitPaneApi
 @Composable
 fun HorizontalSplitPane(
     modifier: Modifier = Modifier,
@@ -85,6 +87,7 @@ fun HorizontalSplitPane(
  * @param isHorizontal describes is it horizontal or vertical split pane
  * @param splitPaneState the state object to be used to control or observe the split pane state
  */
+@OptIn(ExperimentalSplitPaneApi::class)
 internal expect fun defaultSplitter(
     isHorizontal: Boolean,
     splitPaneState: SplitPaneState

components/SplitPane/common/src/commonMain/kotlin/org/jetbrains/compose/splitpane/SplitPaneDSL.kt

@@ -11,6 +11,7 @@ import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
 
 /** Receiver scope which is used by [HorizontalSplitPane] and [VerticalSplitPane] */
+@ExperimentalSplitPaneApi
 interface SplitPaneScope {
 
     /**
@@ -44,12 +45,14 @@ interface SplitPaneScope {
 }
 
 /** Receiver scope which is used by [SplitterScope] */
+@ExperimentalSplitPaneApi
 interface HandleScope {
     /** allow mark composable as movable handle */
     fun Modifier.markAsHandle(): Modifier
 }
 
 /** Receiver scope which is used by [SplitPaneScope] */
+@ExperimentalSplitPaneApi
 interface SplitterScope {
     /**
      * Set up visible part of splitter. This part will be measured and placed between split pane
@@ -65,7 +68,7 @@ interface SplitterScope {
      *
      * @param alignment alignment of handle according to [visiblePart] could be:
      * * [SplitterHandleAlign.BEFORE] if you place handle before [visiblePart],
-     * * [SplitterHandleAlign.ABOVE] if you place handle above [visiblePart] (will be centred)
+     * * [SplitterHandleAlign.ABOVE] if you place handle above [visiblePart] (will be centered)
      * * and [SplitterHandleAlign.AFTER] if you place handle after [visiblePart].
      *
      * @param content composable item content provider. Uses [HandleScope] to allow mark any provided composable part
@@ -74,10 +77,11 @@ interface SplitterScope {
      */
     fun handle(
         alignment: SplitterHandleAlign = SplitterHandleAlign.ABOVE,
-        content: HandleScope.() -> @Composable () -> Unit
+        content: @Composable HandleScope.() -> Unit
     )
 }
 
+@OptIn(ExperimentalSplitPaneApi::class)
 internal class HandleScopeImpl(
     private val containerScope: SplitPaneScopeImpl
 ) : HandleScope {
@@ -91,6 +95,7 @@ internal class HandleScopeImpl(
     }
 }
 
+@OptIn(ExperimentalSplitPaneApi::class)
 internal class SplitterScopeImpl(
     private val containerScope: SplitPaneScopeImpl
 ) : SplitterScope {
@@ -101,15 +106,16 @@ internal class SplitterScopeImpl(
 
     override fun handle(
         alignment: SplitterHandleAlign,
-        content: HandleScope.() -> @Composable () -> Unit
+        content: @Composable HandleScope.() -> Unit
     ) {
-        containerScope.handle = HandleScopeImpl(containerScope).content()
+        containerScope.handle = { HandleScopeImpl(containerScope).content() }
         containerScope.alignment = alignment
     }
 }
 
 private typealias ComposableSlot = @Composable () -> Unit
 
+@OptIn(ExperimentalSplitPaneApi::class)
 internal class SplitPaneScopeImpl(
     internal val isHorizontal: Boolean,
     internal val splitPaneState: SplitPaneState
@@ -168,6 +174,7 @@ internal class SplitPaneScopeImpl(
  * @param moveEnabled the initial value for [SplitPaneState.moveEnabled]
  * @param interactionState the initial value for [SplitPaneState.interactionState]
  * */
+@ExperimentalSplitPaneApi
 @Composable
 fun rememberSplitPaneState(
     initialPositionPercentage: Float = 0f,

components/SplitPane/common/src/commonMain/kotlin/org/jetbrains/compose/splitpane/SplitPaneState.kt

@@ -2,31 +2,22 @@ package org.jetbrains.compose.splitpane
 
 import androidx.compose.foundation.Interaction
 import androidx.compose.foundation.InteractionState
+import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.structuralEqualityPolicy
-
+import androidx.compose.runtime.setValue
 
+@ExperimentalSplitPaneApi
 class SplitPaneState(
     initialPositionPercentage: Float,
     moveEnabled: Boolean,
     private val interactionState: InteractionState
 ) {
 
-    private var _moveEnabled = mutableStateOf(moveEnabled, structuralEqualityPolicy())
-
-    var moveEnabled: Boolean
-        get() = _moveEnabled.value
-        set(newValue) {
-            _moveEnabled.value = newValue
-        }
+    var moveEnabled by mutableStateOf(moveEnabled)
+        internal set
 
-    private val _positionPercentage = mutableStateOf(initialPositionPercentage, structuralEqualityPolicy())
-
-    var positionPercentage: Float
-        get() = _positionPercentage.value
-        internal set(newPosition) {
-            _positionPercentage.value = newPosition
-        }
+    var positionPercentage by mutableStateOf(initialPositionPercentage)
+        internal set
 
     internal var minPosition: Float = 0f
 

components/SplitPane/common/src/commonMain/kotlin/org/jetbrains/compose/splitpane/Splitter.kt

@@ -2,12 +2,14 @@ package org.jetbrains.compose.splitpane
 
 import androidx.compose.runtime.Composable
 
+@ExperimentalSplitPaneApi
 enum class SplitterHandleAlign {
     BEFORE,
     ABOVE,
     AFTER
 }
 
+@OptIn(ExperimentalSplitPaneApi::class)
 internal data class Splitter(
     val measuredPart: @Composable () -> Unit,
     val handlePart: @Composable () -> Unit = measuredPart,

components/SplitPane/common/src/desktopMain/kotlin/org/jetbrains/compose/splitpane/DesktopSplitPane.kt

@@ -11,6 +11,7 @@ private fun Constraints.maxByDirection(isHorizontal: Boolean): Int = if (isHoriz
 private fun Constraints.minByDirection(isHorizontal: Boolean): Int = if (isHorizontal) minWidth else minHeight
 private fun Placeable.valueByDirection(isHorizontal: Boolean): Int = if (isHorizontal) width else height
 
+@OptIn(ExperimentalSplitPaneApi::class)
 @Composable
 internal actual fun SplitPane(
     modifier: Modifier,
@@ -50,10 +51,7 @@ internal actual fun SplitPane(
 
                 if (maxPosition != constrainedMax) {
                     maxPosition =
-                        if ((firstPlaceableMinimalSize + secondPlaceableMinimalSize).value < constraints.maxByDirection(
-                                isHorizontal
-                            )
-                        ) {
+                        if ((firstPlaceableMinimalSize + secondPlaceableMinimalSize).value < constraints.maxByDirection(isHorizontal)) {
                             constrainedMax
                         } else {
                             minPosition
@@ -85,7 +83,8 @@ internal actual fun SplitPane(
                 )
 
                 val splitterPlaceable = measurables[1].measure(constraints)
-                val secondPlaceablePosition = constrainedPosition + splitterPlaceable.valueByDirection(isHorizontal)
+                val splitterSize = splitterPlaceable.valueByDirection(isHorizontal)
+                val secondPlaceablePosition = constrainedPosition + splitterSize
 
                 val secondPlaceableSize =
                     (constraints.maxByDirection(isHorizontal) - secondPlaceablePosition).coerceIn(
@@ -112,10 +111,12 @@ internal actual fun SplitPane(
                 )
 
                 val handlePlaceable = measurables[3].measure(constraints)
+                val handleSize = handlePlaceable.valueByDirection(isHorizontal)
+                // TODO support RTL
                 val handlePosition = when (splitter.align) {
-                    SplitterHandleAlign.BEFORE -> constrainedPosition - handlePlaceable.valueByDirection(isHorizontal)
-                    SplitterHandleAlign.ABOVE -> constrainedPosition - (handlePlaceable.valueByDirection(isHorizontal) / 2)
-                    SplitterHandleAlign.AFTER -> constrainedPosition + handlePlaceable.valueByDirection(isHorizontal)
+                    SplitterHandleAlign.BEFORE -> constrainedPosition - handleSize
+                    SplitterHandleAlign.ABOVE -> constrainedPosition + (splitterSize - handleSize) / 2
+                    SplitterHandleAlign.AFTER -> constrainedPosition + splitterSize + handleSize
                 }
 
                 layout(constraints.maxWidth, constraints.maxHeight) {

components/SplitPane/common/src/desktopMain/kotlin/org/jetbrains/compose/splitpane/DesktopSplitter.kt

@@ -59,8 +59,9 @@ private fun DesktopSplitPaneSeparator(
         .background(color)
 )
 
+@OptIn(ExperimentalSplitPaneApi::class)
 @Composable
-private fun DesctopHandle(
+private fun DesktopHandle(
     isHorizontal: Boolean,
     splitPaneState: SplitPaneState
 ) = Box(
@@ -85,6 +86,7 @@ private fun DesctopHandle(
         }
 )
 
+@OptIn(ExperimentalSplitPaneApi::class)
 internal actual fun defaultSplitter(
     isHorizontal: Boolean,
     splitPaneState: SplitPaneState
@@ -93,7 +95,7 @@ internal actual fun defaultSplitter(
         DesktopSplitPaneSeparator(isHorizontal)
     },
     handlePart = {
-        DesctopHandle(isHorizontal, splitPaneState)
+        DesktopHandle(isHorizontal, splitPaneState)
     }
 )
 

components/SplitPane/desktop/build.gradle.kts

@@ -1,4 +1,5 @@
 import org.jetbrains.compose.compose
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 plugins {
     kotlin("multiplatform")
@@ -22,3 +23,7 @@ compose.desktop {
         mainClass = "org.jetbrains.compose.splitpane.demo.MainKt"
     }
 }
+
+tasks.withType<KotlinCompile>().configureEach {
+    kotlinOptions.freeCompilerArgs += "-Xopt-in=kotlin.RequiresOptIn"
+}

components/SplitPane/desktop/src/jvmMain/kotlin/org/jetbrains/compose/splitpane/demo/Main.kt

@@ -9,8 +9,6 @@ import androidx.compose.foundation.layout.fillMaxHeight
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.width
 import androidx.compose.material.MaterialTheme
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -20,9 +18,8 @@ import androidx.compose.ui.composed
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.SolidColor
 import androidx.compose.ui.input.pointer.pointerMoveFilter
-import androidx.compose.ui.platform.LocalViewConfiguration
-import androidx.compose.ui.platform.ViewConfiguration
 import androidx.compose.ui.unit.dp
+import org.jetbrains.compose.splitpane.ExperimentalSplitPaneApi
 import org.jetbrains.compose.splitpane.HorizontalSplitPane
 import org.jetbrains.compose.splitpane.VerticalSplitPane
 import org.jetbrains.compose.splitpane.rememberSplitPaneState
@@ -44,6 +41,7 @@ private fun Modifier.cursorForHorizontalResize(
     )
 }
 
+@OptIn(ExperimentalSplitPaneApi::class)
 fun main() = Window(
     "SplitPane demo"
 ) {
@@ -77,16 +75,14 @@ fun main() = Window(
                         )
                     }
                     handle {
-                        {
-                            Box(
-                                Modifier
-                                    .markAsHandle()
-                                    .cursorForHorizontalResize()
-                                    .background(SolidColor(Color.Gray), alpha = 0.50f)
-                                    .width(8.dp)
-                                    .fillMaxHeight()
-                            )
-                        }
+                        Box(
+                            Modifier
+                                .markAsHandle()
+                                .cursorForHorizontalResize()
+                                .background(SolidColor(Color.Gray), alpha = 0.50f)
+                                .width(9.dp)
+                                .fillMaxHeight()
+                        )
                     }
                 }
             }