Changeset 274941 in webkit

Timestamp:

Mar 24, 2021, 9:45:11 AM (4 years ago)

Author:

commit-queue@webkit.org

Message:

Ignore middle commits during animated resize
​https://bugs.webkit.org/show_bug.cgi?id=223530

Patch by Sihui Liu <​sihui_liu@appe.com> on 2021-03-24
Reviewed by Tim Horton.

For animated resize, UI process sets layer transform to fit new size until web process picks up size change and
paints. It is possible that UI process receives a commit during animated resize and the commit is not for the
animated resize (web process commits before animated resize). In this case, our current implementation is: if
SPI client species there will be no other update (!_waitingForEndAnimatedResize), we change layer transform to
reflect change of the middle commit.

However, that commit does not mean web process issues new paint, so the adjustment can be wrong. We find the
handling of middle commits causes issues in SPI client's use case (rdar://47623140). Also by manual testing,
it's not clear how the code can benefit current SPI clients. It seems to cause the same trouble sometimes. So
let's just remove it.

• UIProcess/API/ios/WKWebViewIOS.mm:

(-[WKWebView _didCommitLayerTreeDuringAnimatedResize:]):

Location:

trunk/Source/WebKit

Files:

• ChangeLog (modified) (1 diff)
• UIProcess/API/ios/WKWebViewIOS.mm (modified) (1 diff)

trunk/Source/WebKit/ChangeLog

@@ +1 @@
+2021-03-24  Sihui Liu  <sihui_liu@appe.com>
+
+        Ignore middle commits during animated resize
+        https://bugs.webkit.org/show_bug.cgi?id=223530
+
+        Reviewed by Tim Horton.
+
+        For animated resize, UI process sets layer transform to fit new size until web process picks up size change and 
+        paints. It is possible that UI process receives a commit during animated resize and the commit is not for the 
+        animated resize (web process commits before animated resize). In this case, our current implementation is: if 
+        SPI client species there will be no other update (!_waitingForEndAnimatedResize), we change layer transform to
+        reflect change of the middle commit. 
+
+        However, that commit does not mean web process issues new paint, so the adjustment can be wrong. We find the 
+        handling of middle commits causes issues in SPI client's use case  (rdar://47623140). Also by manual testing, 
+        it's not clear how the code can benefit current SPI clients. It seems to cause the same trouble sometimes. So 
+        let's just remove it.
+
+        * UIProcess/API/ios/WKWebViewIOS.mm:
+        (-[WKWebView _didCommitLayerTreeDuringAnimatedResize:]):
+
 2021-03-24  Per Arne  <pvollan@apple.com>
 

trunk/Source/WebKit/UIProcess/API/ios/WKWebViewIOS.mm

@@ -756 +756 @@
 {
     auto updateID = layerTreeTransaction.dynamicViewportSizeUpdateID();
-    if (updateID && *updateID == _currentDynamicViewportSizeUpdateID) {
-        double pageScale = layerTreeTransaction.pageScaleFactor();
-        WebCore::IntPoint scrollPosition = layerTreeTransaction.scrollPosition();
-
-        CGFloat animatingScaleTarget = [[_resizeAnimationView layer] transform].m11;
-        double currentTargetScale = animatingScaleTarget * [[_contentView layer] transform].m11;
-        double scale = pageScale / currentTargetScale;
-        _resizeAnimationTransformAdjustments = CATransform3DMakeScale(scale, scale, 1);
-
-        CGPoint newContentOffset = [self _contentOffsetAdjustedForObscuredInset:CGPointMake(scrollPosition.x() * pageScale, scrollPosition.y() * pageScale)];
-        CGPoint currentContentOffset = [_scrollView contentOffset];
-
-        _resizeAnimationTransformAdjustments.m41 = (currentContentOffset.x - newContentOffset.x) / animatingScaleTarget;
-        _resizeAnimationTransformAdjustments.m42 = (currentContentOffset.y - newContentOffset.y) / animatingScaleTarget;
-
-        [_resizeAnimationView layer].sublayerTransform = _resizeAnimationTransformAdjustments;
-
-        // If we've already passed endAnimatedResize, immediately complete
-        // the resize when we have an up-to-date layer tree. Otherwise,
-        // we will defer completion until endAnimatedResize.
-        _waitingForCommitAfterAnimatedResize = NO;
-        if (!_waitingForEndAnimatedResize)
-            [self _didCompleteAnimatedResize];
-
-        return;
-    }
-
-    // If a commit arrives during the live part of a resize but before the
-    // layer tree takes the current resize into account, it could change the
-    // WKContentView's size. Update the resizeAnimationView's scale to ensure
-    // we continue to fill the width of the resize target.
-
-    if (_waitingForEndAnimatedResize)
-        return;
-
-    auto newViewLayoutSize = [self activeViewLayoutSize:self.bounds];
-    CGFloat resizeAnimationViewScale = _animatedResizeOriginalContentWidth / newViewLayoutSize.width();
-    [[_resizeAnimationView layer] setSublayerTransform:CATransform3DMakeScale(resizeAnimationViewScale, resizeAnimationViewScale, 1)];
+    if (updateID != _currentDynamicViewportSizeUpdateID)
+        return;
+
+    double pageScale = layerTreeTransaction.pageScaleFactor();
+    WebCore::IntPoint scrollPosition = layerTreeTransaction.scrollPosition();
+
+    CGFloat animatingScaleTarget = [[_resizeAnimationView layer] transform].m11;
+    double currentTargetScale = animatingScaleTarget * [[_contentView layer] transform].m11;
+    double scale = pageScale / currentTargetScale;
+    _resizeAnimationTransformAdjustments = CATransform3DMakeScale(scale, scale, 1);
+
+    CGPoint newContentOffset = [self _contentOffsetAdjustedForObscuredInset:CGPointMake(scrollPosition.x() * pageScale, scrollPosition.y() * pageScale)];
+    CGPoint currentContentOffset = [_scrollView contentOffset];
+
+    _resizeAnimationTransformAdjustments.m41 = (currentContentOffset.x - newContentOffset.x) / animatingScaleTarget;
+    _resizeAnimationTransformAdjustments.m42 = (currentContentOffset.y - newContentOffset.y) / animatingScaleTarget;
+
+    [_resizeAnimationView layer].sublayerTransform = _resizeAnimationTransformAdjustments;
+
+    // If we've already passed endAnimatedResize, immediately complete
+    // the resize when we have an up-to-date layer tree. Otherwise,
+    // we will defer completion until endAnimatedResize.
+    _waitingForCommitAfterAnimatedResize = NO;
+    if (!_waitingForEndAnimatedResize)
+        [self _didCompleteAnimatedResize];
 }