836456 - [10.7] Trigger page to bounce with momentum scroll events

Status: RESOLVED DUPLICATE of bug 1124108

(Core :: Widget: Cocoa, defect, P4)

Description

[Stephen A Pohl [:spohl]]

Momentum scroll events past the top or bottom of a page should trigger the page to bounce similar to what is being implemented for bug 673875.

Because NSEvent's trackSwipeEventWithOptions method throws Objective-C exceptions if called with momentum scroll events, this bug does not fall in the context of bug 673875.

Momentum scroll events (in the context of this bug) are events that return YES to nsCocoaUtils::IsMomentumScrollEvent:

 BOOL nsCocoaUtils::IsMomentumScrollEvent(NSEvent* aEvent)
 {
   if ([aEvent type] != NSScrollWheel)
     return NO;
     
   if ([aEvent respondsToSelector:@selector(momentumPhase)])
     return ([aEvent momentumPhase] & NSEventPhaseChanged) != 0;
     
   if ([aEvent respondsToSelector:@selector(_scrollPhase)])
     return [aEvent _scrollPhase] != 0;
     
   return NO;
 }

Comment 3

[Stephen A Pohl [:spohl]]

I'm unlikely to get to this in the next two weeks, so unassigning myself.

Comment 4

[Mike de Boer [:mikedeboer]]

I'm trying to see if we can find a way to move forward with issues that can benefit from APZ awesomeness.

Right now, when I flip the 'apz.overscroll.enabled' pref, I get a smooth stretch animation that I remember from FirefoxOS. Only thing is that it doesn't stretch back when I release my fingers from the trackpad; I have to scroll back a bit to get the page back un-stretched.
On desktop we don't need to worry about patent issues, so we can use the OSX-style bounce animation if we'd like.

Is there some kind of API that the frontend team can use to wire things up, or do we need support from platform?

Comment 5

[Markus Stange [:mstange]]

I have wip patches that implement this with APZ. I'll finish them up once the APZ ship blockers are fixed.

Comment 6

[Markus Stange [:mstange]]

This was implemented in bug 1124108.