Fix AXBoundsForRange in OS X accessibility

When returning a rect for AXBoundsForRange, we always incorporated one
more character. Along with this one more character being often either a
newline or the first character of new softline, visual bounds often got
wrongly and unnecessarily multiline when in fact only single line was
correct.

Also noticeable when moving character by character (VO-Shift-arrow
left/right) - now only one character is being shown (as opposed to two
before). Still due to VoiceOver bug, for bounds of width less than 8
points, it will draw bounds width with of 8 points (reported as
<rdar://problem/19370707>).  But still this is an improvement for cases
with bounds of width more or equal to 8 points.

[ChangeLog][QtGui][Accessibility][OS X] Visual bounds returned by
QTextEdit were singificantly improved, this enables VoiceOver to draw
properly positioned VoiceOver cursor.

Change-Id: Idc50310f8016fbcc01b061d27b655c72922a4807
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@theqtcompany.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm b/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm
index 8a6c27605b..1cb51a37bc 100644
--- a/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm
+++ b/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm
@@ -402,8 +402,17 @@ static void convertLineOffset(QAccessibleTextInterface *text, int &line, int &of
     if ([attribute isEqualToString: NSAccessibilityBoundsForRangeParameterizedAttribute]) {
         NSRange range = [parameter rangeValue];
         QRect firstRect = iface->textInterface()->characterRect(range.location);
-        QRect lastRect = iface->textInterface()->characterRect(range.location + range.length);
-        QRect rect = firstRect.united(lastRect); // This is off quite often, but at least a rough approximation
+        QRect rect;
+        if (range.length > 0) {
+            NSUInteger position = range.location + range.length - 1;
+            if (position > range.location && iface->textInterface()->text(position, position + 1) == QStringLiteral("\n"))
+                --position;
+            QRect lastRect = iface->textInterface()->characterRect(position);
+            rect = firstRect.united(lastRect);
+        } else {
+            rect = firstRect;
+            rect.setWidth(1);
+        }
         return [NSValue valueWithRect: NSMakeRect((CGFloat) rect.x(),(CGFloat) qt_mac_flipYCoordinate(rect.y() + rect.height()), rect.width(), rect.height())];
     }
     if ([attribute isEqualToString: NSAccessibilityAttributedStringForRangeParameterizedAttribute]) {