<AWT Dev> [9] Review request for 8166591 [macos 10.12] Trackpad scrolling of text on OS X 10.12 Sierra is very fast (Trackpad, Retina only)

[Alexander Scherbatiy]

Hello,

Could you review the updated fix:
   http://cr.openjdk.java.net/~alexsch/8166591/webrev.04

The fix uses the proposed changes below and sets a wheel rotation to +1 
or -1 when the scroll phase is ended and the accumulates delta value is 
small than the threshold.

Thanks,
Alexandr.

On 29/09/16 22:56, Sergey Malenkov wrote:
>> - The SCROLL_MASK_PHASE_CANCELLED  and SCROLL_MASK_PHASE_ENDED scroll masks
>> are added.
> Now we use the scrollMask value and the following constants:
>
> static final int SCROLL_MASK_WHEEL = 1;
> static final int SCROLL_MASK_TRACKPAD = 1 << 1;
> static final int SCROLL_MASK_PHASE_BEGAN = 1 << 2;
> static final int SCROLL_MASK_PHASE_CANCELLED = 1 << 3;
> static final int SCROLL_MASK_PHASE_ENDED = 1 << 4;
>
> All these masks cannot be used together.
> So I suggest to replace it with the scrollPhase value:
>
> static final int SCROLL_PHASE_UNSUPPORTED = 0; // for mouse events
> static final int SCROLL_PHASE_BEGAN = 1;
> static final int SCROLL_PHASE_CONTINUED = 2;
> static final int SCROLL_PHASE_CANCELLED = 3;
> static final int SCROLL_PHASE_ENDED = 4;
>
> It simplifies if-statements:
> - if ((scrollMask & NSEvent.SCROLL_MASK_PHASE_BEGAN) != 0) {
> + if (scrollPhase == NSEvent.SCROLL_PHASE_BEGAN) {
>
> and the following method:
>
> + (jint) scrollTypeToMask: (NSEventPhase) phase {
>      if (phase) return SCROLL_PHASE_UNSUPPORTED;
>      switch (phase) {
>          case NSEventPhaseBegan:    return SCROLL_MASK_PHASE_BEGAN;
>          case NSEventPhaseCancelled:    return SCROLL_MASK_PHASE_CANCELLED;
>          case NSEventPhaseEnded:    return SCROLL_MASK_PHASE_ENDED;
>      }
>      return SCROLL_PHASE_CONTINUED;
> }
>
> What do you think?
>