init

window-styler/src/jvmMain/kotlin/com/mayakapps/compose/windowstyler/TransparencyUtils.kt

@@ -0,0 +1,66 @@
+package com.mayakapps.compose.windowstyler
+
+import androidx.compose.ui.awt.ComposeWindow
+import org.jetbrains.skiko.SkiaLayer
+import java.awt.*
+import javax.swing.JComponent
+import javax.swing.JDialog
+import javax.swing.JWindow
+
+internal fun ComposeWindow.setComposeLayerTransparency(isTransparent: Boolean) {
+    skiaLayer.transparency = isTransparent
+}
+
+internal fun Window.hackContentPane() {
+    val oldContentPane = contentPane ?: return
+
+    // Create hacked content pane the same way of AWT
+    val newContentPane: JComponent = HackedContentPane()
+    newContentPane.name = "$name.contentPane"
+    newContentPane.layout = object : BorderLayout() {
+        override fun addLayoutComponent(comp: Component, constraints: Any?) {
+            super.addLayoutComponent(comp, constraints ?: CENTER)
+        }
+    }
+
+    newContentPane.background = Color(0, 0, 0, 0)
+
+    oldContentPane.components.forEach { newContentPane.add(it) }
+
+    contentPane = newContentPane
+}
+
+
+internal val ComposeWindow.skiaLayer: SkiaLayer
+    get() {
+        val delegate = delegateField.get(this)
+        val layer = getLayerMethod.invoke(delegate)
+        return getComponentMethod.invoke(layer) as SkiaLayer
+    }
+
+internal val Window.isTransparent
+    get() = when (this) {
+        is ComposeWindow -> skiaLayer.transparency
+        else -> background.alpha != 255
+    }
+
+internal val Window.isUndecorated
+    get() = when (this) {
+        is Frame -> isUndecorated
+        is JDialog -> isUndecorated
+        is JWindow -> true
+        else -> false
+    }
+
+
+private val delegateField by lazy {
+    ComposeWindow::class.java.getDeclaredField("delegate").apply { isAccessible = true }
+}
+
+private val getLayerMethod by lazy {
+    delegateField.type.getDeclaredMethod("getLayer").apply { isAccessible = true }
+}
+
+private val getComponentMethod by lazy {
+    getLayerMethod.returnType.getDeclaredMethod("getComponent")
+}