[webkit-reviews] review denied: [Bug 172019] elementFromPoint() should consider x and y to be in client (layout viewport) coordinates : [Attachment 314850] Patch

[bugzilla-daemon at webkit.org]

Simon Fraser (smfr) <simon.fraser at apple.com> has denied Ali Juma
<ajuma at chromium.org>'s request for review:
Bug 172019: elementFromPoint() should consider x and y to be in client (layout
viewport) coordinates
https://bugs.webkit.org/show_bug.cgi?id=172019

Attachment 314850: Patch

https://bugs.webkit.org/attachment.cgi?id=314850&action=review




--- Comment #11 from Simon Fraser (smfr) <simon.fraser at apple.com> ---
Comment on attachment 314850
  --> https://bugs.webkit.org/attachment.cgi?id=314850
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=314850&action=review

See the "Coordinate systems:" comment in FrameView.h, and enhance it to add
"layoutViewport" coordinates.

> Source/WebCore/page/FrameView.cpp:4930
> +    ASSERT(frame().settings().visualViewportEnabled());
> +    rect.scale(frame().frameScaleFactor());
> +    return rect;

This seems wrong. layoutViewport -> absolute should be accounting for both the
layout viewport origin, and the frame scale.

> Source/WebCore/page/FrameView.cpp:4936
> +    p.scale(frame().frameScaleFactor());

Ditto.

> Source/WebCore/page/FrameView.cpp:4944
> +    ASSERT(frame().settings().visualViewportEnabled());
> +    p.scale(frame().pageZoomFactor());
> +    p.moveBy(layoutViewportRect().location());

client to layout viewport should just be about pageZoom.

> Source/WebCore/page/FrameView.h:480
> +    FloatRect layoutViewportToAbsoluteRect(FloatRect) const;
> +    FloatPoint layoutViewportToAbsolutePoint(FloatPoint) const;
> +
> +    FloatPoint clientToLayoutViewportPoint(FloatPoint) const;

Please add a comment saying that "layoutViewport" coordinate differ from client
coordinates because of page zoom.