Changeset 248977 in webkit

Timestamp:

Aug 21, 2019, 5:06:38 PM (7 years ago)

Author:

Megan Gardner

Message:

Do not adjust viewport if editing selection is already visible
​https://bugs.webkit.org/show_bug.cgi?id=200907
<rdar://problem/53903417>

Reviewed by Simon Fraser.

Source/WebCore:

Test: fast/scrolling/ios/autoscroll-input-when-very-zoomed.html

Currently due to scrolling being mostly handled by integers, we are getting
issues with rounding errors when trying to adjust the viewport while
editing text when we are significantly zoomed in. The real fix would be to
start dealing with scrolling with floats/doubles, but until such time,
we should early out of adjusting selections that we are certain are currently
visible.

• rendering/RenderLayer.cpp:

(WebCore::RenderLayer::scrollRectToVisible):

LayoutTests:

• fast/scrolling/ios/autoscroll-input-when-very-zoomed-expected.txt: Added.
• fast/scrolling/ios/autoscroll-input-when-very-zoomed.html: Added.
• resources/ui-helper.js:

(window.UIHelper.immediateZoomToScale):

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/scrolling/ios/autoscroll-input-when-very-zoomed-expected.txt (added)
• LayoutTests/fast/scrolling/ios/autoscroll-input-when-very-zoomed.html (added)
• LayoutTests/resources/ui-helper.js (modified) (1 diff)
• Source/WebCore/ChangeLog (modified) (1 diff)
• Source/WebCore/rendering/RenderLayer.cpp (modified) (1 diff)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2019-08-21  Megan Gardner  <megan_gardner@apple.com>
+
+        Do not adjust viewport if editing selection is already visible
+        https://bugs.webkit.org/show_bug.cgi?id=200907
+        <rdar://problem/53903417>
+
+        Reviewed by Simon Fraser.
+
+        * fast/scrolling/ios/autoscroll-input-when-very-zoomed-expected.txt: Added.
+        * fast/scrolling/ios/autoscroll-input-when-very-zoomed.html: Added.
+        * resources/ui-helper.js:
+        (window.UIHelper.immediateZoomToScale):
+
 2019-08-21  Tim Horton  <timothy_horton@apple.com>
 

trunk/LayoutTests/resources/ui-helper.js

@@ -709 +709 @@
     }
 
+    static immediateZoomToScale(scale)
+    {
+        const uiScript = `uiController.immediateZoomToScale(${scale})`;
+        return new Promise(resolve => testRunner.runUIScript(uiScript, resolve));
+    }
+
     static typeCharacter(characterString)
     {

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-08-21  Megan Gardner  <megan_gardner@apple.com>
+
+        Do not adjust viewport if editing selection is already visible
+        https://bugs.webkit.org/show_bug.cgi?id=200907
+        <rdar://problem/53903417>
+
+        Reviewed by Simon Fraser.
+
+        Test: fast/scrolling/ios/autoscroll-input-when-very-zoomed.html
+
+        Currently due to scrolling being mostly handled by integers, we are getting
+        issues with rounding errors when trying to adjust the viewport while
+        editing text when we are significantly zoomed in. The real fix would be to 
+        start dealing with scrolling with floats/doubles, but until such time,
+        we should early out of adjusting selections that we are certain are currently
+        visible.
+
+        * rendering/RenderLayer.cpp:
+        (WebCore::RenderLayer::scrollRectToVisible):
+
 2019-08-21  Tim Horton  <timothy_horton@apple.com>
 

trunk/Source/WebCore/rendering/RenderLayer.cpp

@@ -2702 +2702 @@
 
             LayoutRect revealRect = getRectToExpose(viewRect, targetRect, insideFixed, options.alignX, options.alignY);
-            ScrollOffset clampedScrollPosition = roundedIntPoint(revealRect.location()).constrainedBetween(minScrollPosition, maxScrollPosition);
-            frameView.setScrollPosition(clampedScrollPosition);
+            // Avoid scrolling to the rounded value of revealRect.location() if we don't actually need to scroll
+            if (revealRect != viewRect) {
+                ScrollOffset clampedScrollPosition = roundedIntPoint(revealRect.location()).constrainedBetween(minScrollPosition, maxScrollPosition);
+                frameView.setScrollPosition(clampedScrollPosition);
+            }
 
             // This is the outermost view of a web page, so after scrolling this view we