Bug 76244 – REGRESSION(r100111): A 'change' event does not fire when a mouse drag occurs to switch elements in a listbox

• Status: RESOLVED
• Resolution: FIXED
• Component: Forms

[Kent Tamura]

Reported at http://code.google.com/p/chromium/issues/detail?id=110068.


<select id="sel1" size="4" onchange="alert('event fired: ' + document.getElementById('sel1').value);">
<option>RED</option>
<option>GREEN</option>
<option>BLUE</option>
<option>YELLOW</option>
</select>

If you select an option by mouse dragging (not clicking), 'change' event doesn't fire. This problem was made by r99667 or r100111.

[Kent Tamura]

The root cause is that the mousedown handling in listBoxDefaultEventHandler() updates m_lastOnChangeSelection. If the listbox is scrollable, mousemove events are not dispatched.

[Kent Tamura]

Created attachment 122874 [details]
Patch

[Hajime Morrita]

Comment on attachment 122874 [details]
Patch

The test shows the evidence.

[Kent Tamura]

(In reply to comment #1)
> The root cause is that the mousedown handling in listBoxDefaultEventHandler() updates m_lastOnChangeSelection. If the listbox is scrollable, mousemove events are not dispatched.

Correction: mousedown -> mousemove

BTW, HTMLSelectElement has multiple functions to update option selection, and they are confusing. We had better refactor/rename/document them.

[WebKit Review Bot]

Comment on attachment 122874 [details]
Patch

Attachment 122874 [details] did not pass chromium-ews (chromium-xvfb):
Output: http://queues.webkit.org/results/11282082

New failing tests:
fast/forms/select-multiple-elements-with-mouse-drag-with-options-less-than-size.html

[Kent Tamura]

(In reply to comment #5)
> (From update of attachment 122874 [details])
> Attachment 122874 [details] did not pass chromium-ews (chromium-xvfb):
> Output: http://queues.webkit.org/results/11282082
> 
> New failing tests:
> fast/forms/select-multiple-elements-with-mouse-drag-with-options-less-than-size.html

The test didn't fail on Apple Mac and Chromium Mac with the patch.

[Kent Tamura]

Created attachment 123050 [details]
Patch for landing

[WebKit Review Bot]

Comment on attachment 123050 [details]
Patch for landing

Clearing flags on attachment: 123050

Committed r105386: <http://trac.webkit.org/changeset/105386>

[WebKit Review Bot]

All reviewed patches have been landed.  Closing bug.