Bug 84181 – DevTools highlights elements in frames at un-scaled positions

• Component: Web Inspector (Deprecated)
• Status: RESOLVED FIXED

[Xianzhu Wang]

Reproduced on chromium-android (with page scaling).

1. On device, open www.gmail.com and login and switch to desktop version
2. start DevTools on the host to inspect the gmail page
3. In DevTools Elements pane, hover any element in the "canvas_frame" iframe.

Observed behavior:
The highlighted position is not the actual position of the hovered element, but the un-scaled position

Expected Behavior:
Should highlight the correct position of the element

Will upload a patch soon.

[Xianzhu Wang]

Created attachment 137600 [details]
patch

[Pavel Feldman]

Comment on attachment 137600 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=137600&action=review

> Source/WebCore/ChangeLog:8
> +        Test: inspector/elements/highlight-node-scaled.html

Please explain what changed and why in the ChangeLog. I can't reproduce it on ToT Chromium. Also, I am not sure what you expect to "scale" in a given test case.

[Xianzhu Wang]

Created attachment 137715 [details]
patch v2 (added comments in ChangeLog)

(In reply to comment #2)
> Please explain what changed and why in the ChangeLog. I can't reproduce it on ToT Chromium. Also, I am not sure what you expect to "scale" in a given test case.

Sorry for not being clear in the last patch. Added comments in ChangeLog in this patch.

The scaling feature is used on some mobile platforms, e.g. chromium-android. However, the issue can be reproduced on all platforms with the new test case which forces scaling with window.internals.settings.setPageScale(2, 0, 0). The change uses FrameView::contentsToRootView() to map the coordinates of a node in a frame to the coordinates in the main view, instead of calculating by only the offsets.

[Pavel Feldman]

Comment on attachment 137715 [details]
patch v2 (added comments in ChangeLog)

View in context: https://bugs.webkit.org/attachment.cgi?id=137715&action=review

> LayoutTests/inspector/elements/highlight-node-scaled.html:39
> +    window.internals.settings.setPageScaleFactor(2, 0, 0);

This should be:
if (window.internals)
    window.internals.settings.setPageScaleFactor(2, 0, 0);

So that the test could be loaded outside DRT.

[Xianzhu Wang]

Comment on attachment 137715 [details]
patch v2 (added comments in ChangeLog)

View in context: https://bugs.webkit.org/attachment.cgi?id=137715&action=review

>> LayoutTests/inspector/elements/highlight-node-scaled.html:39
>> +    window.internals.settings.setPageScaleFactor(2, 0, 0);
> 
> This should be:
> if (window.internals)
>     window.internals.settings.setPageScaleFactor(2, 0, 0);
> 
> So that the test could be loaded outside DRT.

Done. Thanks!

[Xianzhu Wang]

Created attachment 137913 [details]
patch for landing

[Pavel Feldman]

Comment on attachment 137913 [details]
patch for landing

Thanks.

[WebKit Review Bot]

Comment on attachment 137913 [details]
patch for landing

Clearing flags on attachment: 137913

Committed r114659: <http://trac.webkit.org/changeset/114659>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.

[Jer Noble]

This changeset is causing a crash in inspector/elements/elements-panel-selection-on-refresh.html.

Filed https://bugs.webkit.org/show_bug.cgi?id=84492 to track the new crash.