fix issue with iOS boundsInWindow incorrect size (#1093)

https://youtrack.jetbrains.com/issue/COMPOSE-902/iOS-scene-size-after-sending-the-app-to-background-or-changing-orientation-with-open-modal

compose/ui/ui/src/skikoMain/kotlin/androidx/compose/ui/scene/ComposeScene.skiko.kt

@@ -93,6 +93,8 @@ interface ComposeScene {
      * The size is used to impose constraints on the content. If the size is undefined, it can be
      * set to `null`. In such a case, the content will be laid out without any restrictions and
      * the window size will be utilized to bounds verification.
+     *
+     * TODO split boundsInWindow and size https://youtrack.jetbrains.com/issue/COMPOSE-964
      */
     var boundsInWindow: IntRect?
 

compose/ui/ui/src/uikitMain/kotlin/androidx/compose/ui/platform/PlatformWindowContext.uikit.kt

@@ -17,11 +17,13 @@
 package androidx.compose.ui.platform
 
 import androidx.compose.ui.input.pointer.PointerKeyboardModifiers
+import androidx.compose.ui.toDpOffset
 import androidx.compose.ui.uikit.systemDensity
-import androidx.compose.ui.toDpRect
-import androidx.compose.ui.unit.IntRect
+import androidx.compose.ui.unit.IntOffset
 import androidx.compose.ui.unit.IntSize
-import androidx.compose.ui.unit.roundToIntRect
+import androidx.compose.ui.unit.round
+import androidx.compose.ui.unit.toOffset
+import kotlinx.cinterop.cValue
 import kotlinx.cinterop.useContents
 import platform.UIKit.UIView
 
@@ -57,25 +59,23 @@ internal class PlatformWindowContext {
     }
 
     /**
-     * Calculates the bounds of the given [container] within the window.
+     * Calculates the offset of the given [container] within the window.
      * It uses [_windowContainer] as a reference for window coordinate space.
      *
-     * @param container The container component whose bounds need to be calculated.
-     * @return The bounds of the container within the window as an [IntRect] object.
+     * @param container The container component whose offset needs to be calculated.
+     * @return The offset of the container within the window as an [IntOffset] object.
      */
-    fun boundsInWindow(container: UIView): IntRect {
+    fun offsetInWindow(container: UIView): IntOffset {
         val density = container.systemDensity
         return if (_windowContainer != null && _windowContainer != container) {
-            container.convertRect(
-                rect = container.bounds,
+            container.convertPoint(
+                point = cValue { container.bounds.useContents { origin } },
                 toView = _windowContainer,
             )
         } else {
-            container.bounds
+            cValue { container.bounds.useContents { origin } }
         }.useContents {
-            with(density) {
-                toDpRect().toRect().roundToIntRect()
-            }
+            toDpOffset().toOffset(density).round()
         }
     }
 }

compose/ui/ui/src/uikitMain/kotlin/androidx/compose/ui/scene/ComposeSceneMediator.uikit.kt

@@ -51,6 +51,7 @@ import androidx.compose.ui.uikit.LocalKeyboardOverlapHeight
 import androidx.compose.ui.unit.DpOffset
 import androidx.compose.ui.unit.DpRect
 import androidx.compose.ui.unit.IntRect
+import androidx.compose.ui.unit.IntSize
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.round
 import androidx.compose.ui.unit.roundToIntRect
@@ -107,7 +108,7 @@ private class SemanticsOwnerListenerImpl(
     private val container: UIView,
     private val coroutineContext: CoroutineContext,
     private val getAccessibilitySyncOptions: () -> AccessibilitySyncOptions
-): PlatformContext.SemanticsOwnerListener {
+) : PlatformContext.SemanticsOwnerListener {
     var current: Pair<SemanticsOwner, AccessibilityMediator>? = null
 
     override fun onSemanticsOwnerAppended(semanticsOwner: SemanticsOwner) {
@@ -143,7 +144,7 @@ private class RenderingUIViewDelegateImpl(
     private val interopContext: UIKitInteropContext,
     private val getBoundsInPx: () -> IntRect,
     private val scene: ComposeScene
-): RenderingUIView.Delegate {
+) : RenderingUIView.Delegate {
     override fun retrieveInteropTransaction(): UIKitInteropTransaction =
         interopContext.retrieve()
 
@@ -158,7 +159,7 @@ private class RenderingUIViewDelegateImpl(
 
 private class NativeKeyboardVisibilityListener(
     private val keyboardVisibilityListener: KeyboardVisibilityListenerImpl
-): NSObject() {
+) : NSObject() {
     @Suppress("unused")
     @ObjCAction
     fun keyboardWillShow(arg: NSNotification) {
@@ -172,7 +173,7 @@ private class NativeKeyboardVisibilityListener(
     }
 }
 
-private class ComposeSceneMediatorRootUIView: UIView(CGRectZero.readValue()) {
+private class ComposeSceneMediatorRootUIView : UIView(CGRectZero.readValue()) {
     override fun hitTest(point: CValue<CGPoint>, withEvent: UIEvent?): UIView? {
         // forwards touches forward to the children, is never a target for a touch
         val result = super.hitTest(point, withEvent)
@@ -498,8 +499,21 @@ internal class ComposeSceneMediator(
         //TODO: Current code updates layout based on rootViewController size.
         // Maybe we need to rewrite it for SingleLayerComposeScene.
 
-        val boundsInWindow = windowContext.boundsInWindow(container)
+        val offsetInWindow = windowContext.offsetInWindow(container)
+        val size = container.bounds.useContents {
+            with(density) {
+                toDpRect().toRect().roundToIntRect()
+            }
+        }
+        val boundsInWindow = IntRect(
+            offset = offsetInWindow,
+            size = IntSize(
+                width = size.width,
+                height = size.height,
+            )
+        )
         scene.density = density // TODO: Maybe it is wrong to set density to scene here?
+        // TODO: it should be updated on any container bounds change: resize or move itself or any parent
         scene.boundsInWindow = boundsInWindow
         onComposeSceneInvalidate()
     }