Changeset 255827 in webkit

Timestamp:

Feb 5, 2020 10:22:02 AM (4 years ago)

Author:

Wenson Hsieh

Message:

[macCatalyst] IBeam cursor doesn't show up when hovering over text form controls prior to editing
​https://bugs.webkit.org/show_bug.cgi?id=207268
<rdar://problem/59188152>

Reviewed by Tim Horton.

On macCatalyst, when hovering over textareas and input fields that have not been edited yet, the cursor fails to
change to an IBeam and instead falls back to the default style. Even though EventHandler::selectCursor()
returns IBeam, we end up not actually using an IBeam because the position information's lineCaretExtent is
an empty rect, which means the caret height is 0 and, more importantly, the line rect will not contain the
request point.

The line rect is empty in text fields that have not been edited yet because the form control's inner plaintext
contenteditable div (embedded in the shadow root) does not contain any child renderers with a non-zero height.
Even if it did, however, the element may still be much taller than the combined height of the inner div's
children, so the line rect may still not contain the position information request point (this is most easily
noticeable when focusing a textarea, typing a few letters, and then moving the cursor to near the bottom of the
textarea element).

To fix this, add a fallback path for the scenario where we want to show an IBeam, but fail to find line rects
that contain the request point. Instead, we still show an IBeam, but simply fake the lineCaretExtent to be an
element-wide rect that is the height of the caret, and is also vertically centered about the request point.

• WebProcess/WebPage/ios/WebPageIOS.mm:

(WebKit::populateCaretContext):

Location:

trunk/Source/WebKit

Files:

• ChangeLog (modified) (1 diff)
• WebProcess/WebPage/ios/WebPageIOS.mm (modified) (1 diff)

trunk/Source/WebKit/ChangeLog

@@ +1 @@
+2020-02-05  Wenson Hsieh  <wenson_hsieh@apple.com>
+
+        [macCatalyst] IBeam cursor doesn't show up when hovering over text form controls prior to editing
+        https://bugs.webkit.org/show_bug.cgi?id=207268
+        <rdar://problem/59188152>
+
+        Reviewed by Tim Horton.
+
+        On macCatalyst, when hovering over textareas and input fields that have not been edited yet, the cursor fails to
+        change to an IBeam and instead falls back to the default style. Even though `EventHandler::selectCursor()`
+        returns `IBeam`, we end up not actually using an IBeam because the position information's `lineCaretExtent` is
+        an empty rect, which means the caret height is 0 and, more importantly, the line rect will not contain the
+        request point.
+
+        The line rect is empty in text fields that have not been edited yet because the form control's inner plaintext
+        contenteditable div (embedded in the shadow root) does not contain any child renderers with a non-zero height.
+        Even if it did, however, the element may still be much taller than the combined height of the inner div's
+        children, so the line rect may still not contain the position information request point (this is most easily
+        noticeable when focusing a textarea, typing a few letters, and then moving the cursor to near the bottom of the
+        textarea element).
+
+        To fix this, add a fallback path for the scenario where we want to show an IBeam, but fail to find line rects
+        that contain the request point. Instead, we still show an IBeam, but simply fake the lineCaretExtent to be an
+        element-wide rect that is the height of the caret, and is also vertically centered about the request point.
+
+        * WebProcess/WebPage/ios/WebPageIOS.mm:
+        (WebKit::populateCaretContext):
+
 2020-02-05  Commit Queue  <commit-queue@webkit.org>
 

trunk/Source/WebKit/WebProcess/WebPage/ios/WebPageIOS.mm

@@ -2818 +2818 @@
     info.caretHeight = info.lineCaretExtent.height();
 
+    bool lineContainsRequestPoint = info.lineCaretExtent.contains(request.point);
     // Force an I-beam cursor if the page didn't request a hand, and we're inside the bounds of the line.
-    if (info.lineCaretExtent.contains(request.point) && info.cursor->type() != Cursor::Hand && canForceCaretForPosition(position))
+    if (lineContainsRequestPoint && info.cursor->type() != Cursor::Hand && canForceCaretForPosition(position))
         info.cursor = Cursor::fromType(Cursor::IBeam);
+
+    if (!lineContainsRequestPoint && info.cursor->type() == Cursor::IBeam) {
+        auto approximateLineRectInContentCoordinates = renderer->absoluteBoundingBoxRect();
+        approximateLineRectInContentCoordinates.setHeight(position.absoluteCaretBounds().height());
+        info.lineCaretExtent = view->contentsToRootView(approximateLineRectInContentCoordinates);
+        info.lineCaretExtent.setY(request.point.y() - info.lineCaretExtent.height() / 2);
+        info.caretHeight = info.lineCaretExtent.height();
+    }
 }