iOS: orientation-validate canvas size on iPad foreground (#4767) (#4853)

The previous attempt (a09b916) silenced viewWillTransitionToSize: during
background but then called updateCanvas: synchronously inside
cn1ApplicationWillEnterForeground. On iPad with UIScene, view.bounds can
still be in the snapshot orientation at that moment, so updateCanvas
republished the swapped dimensions through screenSizeChanged -- the same
behavior the issue reports as a transient wrong size between stop and
start.

This change combines two safeguards: it restores the next-runloop
deferral around the foreground updateCanvas call so UIKit has a tick to
settle the bounds, and it cross-checks the sampled size against the
windowScene's interfaceOrientation, swapping the dimensions when they
contradict it. The orientation is authoritative for what the user
actually sees, so this catches the failure even when the deferred call
still fires before UIKit has fully restored bounds.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: shai-almog

Ports/iOSPort/nativeSources/CodenameOne_GLAppDelegate.m

@@ -248,7 +248,16 @@ - (void)cn1ApplicationWillEnterForeground
     com_codename1_impl_ios_IOSImplementation_applicationWillEnterForeground__(CN1_THREAD_GET_STATE_PASS_SINGLE_ARG);
     CodenameOne_GLViewController* vc = [CodenameOne_GLViewController instance];
     if (vc != nil) {
-        [vc updateCanvas:YES];
+        // Defer to the next runloop so UIKit can settle the view bounds
+        // after the snapshot rotation. updateCanvas itself also
+        // orientation-validates the bounds for an extra safety net under
+        // UIScene on iPad (issue #4767).
+        dispatch_async(dispatch_get_main_queue(), ^{
+            CodenameOne_GLViewController* deferredVc = [CodenameOne_GLViewController instance];
+            if (deferredVc != nil) {
+                [deferredVc updateCanvas:YES];
+            }
+        });
     }
 }
 

Ports/iOSPort/nativeSources/CodenameOne_GLViewController.m

@@ -167,6 +167,33 @@ static void updateDisplayMetricsFromView(UIView *view) {
     displayWidth = (int)(view.bounds.size.width * scaleValue);
     displayHeight = (int)(view.bounds.size.height * scaleValue);
 }
+
+// On iPad with UIScene, view.bounds (and even window.bounds) can transiently
+// be in the snapshot orientation between sceneDidEnterBackground and the
+// first post-foreground layout pass. Cross-check against the windowScene's
+// interfaceOrientation -- which reflects what the user actually sees -- and
+// swap the dimensions if they contradict it. Without this, sampling bounds
+// during the foreground transition publishes a swapped-dimension
+// screenSizeChanged event between stop and start (issue #4767).
+static CGSize cn1OrientationCorrectSize(UIView *view) {
+    CGSize size = view.bounds.size;
+#if __IPHONE_OS_VERSION_MAX_ALLOWED >= 130000
+    if (@available(iOS 13.0, *)) {
+        UIWindowScene *scene = view.window.windowScene;
+        if (scene != nil) {
+            UIInterfaceOrientation o = scene.interfaceOrientation;
+            if (o != UIInterfaceOrientationUnknown) {
+                BOOL shouldBePortrait = UIInterfaceOrientationIsPortrait(o);
+                BOOL isPortrait = size.height >= size.width;
+                if (shouldBePortrait != isPortrait) {
+                    return CGSizeMake(size.height, size.width);
+                }
+            }
+        }
+    }
+#endif
+    return size;
+}
 BOOL forceSlideUpField;
 static UIScrollView *cn1StatusBarTapProxy = nil;
 
@@ -2020,22 +2047,22 @@ -(void)updateCanvas:(BOOL)animated {
     if(touchesArray != nil) {
         [touchesArray removeAllObjects];
     }
-    int currentWidth = (int)self.view.bounds.size.width * scaleValue;
+    CGSize size = cn1OrientationCorrectSize(self.view);
     //if(currentWidth != displayWidth) {
     // Note:  While it may be tempting to only update the frame buffer if the size has changed,
-    // doing that causes a bug whereby the app may paint with the wrong dimensions 
+    // doing that causes a bug whereby the app may paint with the wrong dimensions
     // when opening from the background on iPad with multitasking enabled.
     // https://github.com/codenameone/CodenameOne/issues/2819
     // This may be caused by the fact the getDisplayWidthImpl() and getDisplayHeightImpl() update
     // the display width/height each time to match the view, without performing other resizing
     // details, so it is possible that the size change event still needs to be sent
     // even if the display width already matches the value we're given here.
-    [[self eaglView] updateFrameBufferSize:(int)self.view.bounds.size.width h:(int)self.view.bounds.size.height];
-    updateDisplayMetricsFromView(self.view);
-    displayWidth = currentWidth;
+    [[self eaglView] updateFrameBufferSize:(int)size.width h:(int)size.height];
+    displayWidth = (int)size.width * scaleValue;
+    displayHeight = (int)size.height * scaleValue;
     screenSizeChanged(displayWidth, displayHeight);
     //}
-    
+
 }
 
 - (BOOL)canBecomeFirstResponder {