Added tutorial on Swing integration.

tutorials/Swing_Integration/README.md

@@ -0,0 +1,152 @@
+# Integration Compose for Desktop into Swing-based aplication
+
+## What is covered
+
+In this tutorial, we will show you how to use ComposePanel in your Swing application.
+
+## Using ComposePanel
+
+ComposePanel lets you create a UI using Compose for Desktop in a Swing-based UI. To achieve that you need to create instance of ComposePanel, add it to your Swing layout and describe composition inside `setContent`. Also you may need to crear the CFD application events via `AppManager.setEvents`.
+
+```kotlin
+import androidx.compose.desktop.AppManager
+import androidx.compose.desktop.ComposePanel
+import androidx.compose.desktop.setContent
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.Text
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.Button
+import androidx.compose.material.Surface
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.MutableState
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import java.awt.BorderLayout
+import java.awt.Dimension
+import java.awt.event.ActionEvent
+import java.awt.event.ActionListener
+import javax.swing.JFrame
+import javax.swing.JButton
+import javax.swing.SwingUtilities
+import javax.swing.WindowConstants
+
+val northClicks = mutableStateOf(0)
+val westClicks = mutableStateOf(0)
+val eastClicks = mutableStateOf(0)
+
+fun main() {
+    // explicitly clear the application events
+    AppManager.setEvents(
+        onAppStart = null,
+        onAppExit = null,
+        onWindowsEmpty = null
+    )
+    SwingComposeWindow()
+}
+
+fun SwingComposeWindow() {
+    val window = JFrame()
+
+    // creating ComposePanel
+    val composePanel = ComposePanel()
+    window.defaultCloseOperation = WindowConstants.EXIT_ON_CLOSE
+    window.title = "SwingComposeWindow"
+
+
+    window.contentPane.add(actionButton("NORTH", { northClicks.value++ }), BorderLayout.NORTH)
+    window.contentPane.add(actionButton("WEST", { westClicks.value++ }), BorderLayout.WEST)
+    window.contentPane.add(actionButton("EAST", { eastClicks.value++ }), BorderLayout.EAST)
+    window.contentPane.add(
+        actionButton(
+            text = "SOUTH/REMOVE COMPOSE",
+            action = {
+                window.contentPane.remove(composePanel)
+            }
+        ),
+        BorderLayout.SOUTH
+    )
+
+    // addind ComposePanel on JFrame
+    window.contentPane.add(composePanel, BorderLayout.CENTER)
+
+    // setting the content
+    composePanel.setContent {
+        ComposeContent()
+    }
+
+    window.setSize(800, 600)
+    window.setVisible(true)
+}
+
+fun actionButton(text: String, action: (() -> Unit)? = null): JButton {
+    val button = JButton(text)
+    button.setToolTipText("Tooltip for $text button.")
+    button.setPreferredSize(Dimension(100, 100))
+    button.addActionListener(object : ActionListener {
+        public override fun actionPerformed(e: ActionEvent) {
+            action?.invoke()
+        }
+    })
+
+    return button
+}
+
+@Composable
+fun ComposeContent() {
+    Box(
+        modifier = Modifier.fillMaxSize(),
+        alignment = Alignment.Center
+    ) {
+        Row {
+            Counter("West", westClicks)
+            Spacer(modifier = Modifier.width(25.dp))
+            Counter("North", northClicks)
+            Spacer(modifier = Modifier.width(25.dp))
+            Counter("East", eastClicks)
+        }
+    }
+}
+
+@Composable
+fun Counter(text: String, counter: MutableState<Int>) {
+    Surface(
+        modifier = Modifier.size(130.dp, 130.dp),
+        color = Color(180, 180, 180),
+        shape = RoundedCornerShape(4.dp)
+    ) {
+        Column {
+            Box(
+                modifier = Modifier.height(30.dp).fillMaxWidth(),
+                alignment = Alignment.Center
+            ) {
+                Text(text = "${text}Clicks: ${counter.value}")
+            }
+            Spacer(modifier = Modifier.height(25.dp))
+            Box(
+                modifier = Modifier.fillMaxSize(),
+                alignment = Alignment.Center
+            ) {
+                Button(onClick = { counter.value++ }) {
+                    Text(text = text, color = Color.White)
+                }
+            }
+        }
+    }
+}
+```
+
+![IntegrationWithSwing](screenshot.png)
+
+### Note. Adding a Swing component to CFD composition is not currently supported.