483733 - Caret is invisible at far left position in RTL text input boxes

Status: NEW

(Core :: DOM: Editor, defect, P5)

Description

[Chris Pearce [:cpearce (Not reading bugmail)]]

This bug was discovered in bug 483564. In the testcase (see URL) on Windows, when you select the RTL div and move the caret (with arrow keys or home key) to the far left, the caret disappears. This regressed between 2006-11-01-04 and 2006-11-02-04.

Comment 1

[Karl Tomlinson (:karlt)]

nsCaret::UpdateCaretRects clamps the rect to the scroll frame and then adjusts the rect based on the clamping.  The adjustment should probably happen before clamping, but the clamping is only at the right hand end anyway.

  // Clamp our position to be within our scroll frame. If we don't, then it
  // clips us, and we don't appear at all. See bug 335560.
  nsIFrame *scrollFrame =
    nsLayoutUtils::GetClosestFrameOfType(aFrame, nsGkAtoms::scrollFrame);
  if (scrollFrame)
  {
    // First, use the scrollFrame to get at the scrollable view that we're in.
    nsIScrollableFrame *scrollable = do_QueryFrame(scrollFrame);
    nsIScrollableView *scrollView = scrollable->GetScrollableView();
    nsIView *view;
    scrollView->GetScrolledView(view);

    // Compute the caret's coordinates in the enclosing view's coordinate
    // space. To do so, we need to correct for both the original frame's
    // offset from the scrollframe, and the scrollable view's offset from the
    // scrolled frame's view.
    nsPoint toScroll = aFrame->GetOffsetTo(scrollFrame) -
      view->GetOffsetTo(scrollFrame->GetView());
    nsRect caretInScroll = mCaretRect + toScroll;

    // Now see if thet caret extends beyond the view's bounds. If it does,
    // then snap it back, put it as close to the edge as it can.
    nscoord overflow = caretInScroll.XMost() - view->GetBounds().width;
    if (overflow > 0)
      mCaretRect.x -= overflow;
  }

  // on RTL frames the right edge of mCaretRect must be equal to framePos
  const nsStyleVisibility* vis = aFrame->GetStyleVisibility();
  if (NS_STYLE_DIRECTION_RTL == vis->mDirection)
    mCaretRect.x -= mCaretRect.width;

Comment 2

[Jens Stutte [:jstutte]]

Bulk-downgrade of unassigned, untouched DOM/Storage bug's priority.

If you have reason to believe, this is wrong, please write a comment and ni :jstutte.