1842276 - Run helper_scrollbartrack_click_overshoot.html on Linux

Status: RESOLVED FIXED

(Core :: Layout: Scrolling and Overflow, task, P3)

Description

[Botond Ballo [:botond]]

Our scrollbar track click-and-hold behavior varies between platforms:

• Windows/Mac: thumb moves towards mouse position and stops there
• Linux: thumb continues past mouse position until reaching the opposite end of the track
  • (This is with the GTK setting gtk-primary-button-warps-slider disabled. If that setting is enabled, the thumb jumps immediately under the mouse cursor when you click, and there is no additional behaviour associated with the "hold".)

The choice between these two behaviours is currently baked in at compile time using an #ifdef.

In bug 1331390, we fixed a bug affecting the Windows/Mac behaviour. The fact that the behaviour is controlled with an #ifdef has been an impediment to development and testing (e.g. to reproduce the bug on Linux, we had manually tweak the #ifdef).

I'd like to propose controlling the behaviour with a pref instead. This will have the benefit of allowing the test we added in bug 1331390 to run on Linux, and also provides mroe flexibility in case some users prefer the behaviour that's not the default for their platform.

Comment 1

[Botond Ballo [:botond]]

Attachment: Bug 1842276 - Allow dynamically choosing whether scrollbar track click-and-hold has the 'Linux behavior' or the 'Windows/Mac behavior'. r=rzvncj

Comment 2

[Botond Ballo [:botond]]

Attachment: Bug 1842276 - Enable helper_scrollbartrack_click_overshoot.html on Linux. r=rzvncj

Depends on D183038

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/493bee101781
Allow dynamically choosing whether scrollbar track click-and-hold has the 'Linux behavior' or the 'Windows/Mac behavior'. r=rzvncj
https://hg.mozilla.org/integration/autoland/rev/93861bb274d4
Enable helper_scrollbartrack_click_overshoot.html on Linux. r=rzvncj

Comment 4

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/493bee101781
https://hg.mozilla.org/mozilla-central/rev/93861bb274d4