events: Clean up dispatching code for touch-events.

events: Clean up dispatching code for touch-events.

Unlike all other events, touch-events can be processed asynchronously, and
this complicates using the same code-path used for other events for touch
events. This change adds a generic EventResult::ER_ASYNC for these cases,
and updates the code in events, aura and gesture recognizer to use EventResult
instead of TouchStatus.

The code in views still uses TouchStatus. But it will be cleaned up.

BUG=none

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=159059

[Ben Goodger (Google), 2012-09-26 19:42:48]

http://codereview.chromium.org/10964051/diff/1038/ui/aura/gestures/gesture_re...
File ui/aura/gestures/gesture_recognizer_unittest.cc (right):

http://codereview.chromium.org/10964051/diff/1038/ui/aura/gestures/gesture_re...
ui/aura/gestures/gesture_recognizer_unittest.cc:293: return ui::ER_ASYNC;
you can use a ternary here, it should fit on one line

return queue_events_ ? ui::ER_ASYNC : ui::ER_UNHANDLED;

http://codereview.chromium.org/10964051/diff/1038/ui/base/events/event_consta...
File ui/base/events/event_constants.h (right):

http://codereview.chromium.org/10964051/diff/1038/ui/base/events/event_consta...
ui/base/events/event_constants.h:107: ER_ASYNC     = 1 << 2,  // The event will
be processed asynchronously. The
Can you tell me how 'asynchronously' works and what this return code would be
interpreted by the caller?

http://codereview.chromium.org/10964051/diff/1038/ui/views/widget/desktop_nat...
File ui/views/widget/desktop_native_widget_aura.cc (right):

http://codereview.chromium.org/10964051/diff/1038/ui/views/widget/desktop_nat...
ui/views/widget/desktop_native_widget_aura.cc:442: case
ui::TOUCH_STATUS_UNKNOWN:
should you have a function in ui/base/events that has this switch statement?
i've seen it a couple of times in this cl.

[sadrul, 2012-09-26 21:26:05]

http://codereview.chromium.org/10964051/diff/1038/ui/aura/gestures/gesture_re...
File ui/aura/gestures/gesture_recognizer_unittest.cc (right):

http://codereview.chromium.org/10964051/diff/1038/ui/aura/gestures/gesture_re...
ui/aura/gestures/gesture_recognizer_unittest.cc:293: return ui::ER_ASYNC;
On 2012/09/26 19:42:48, Ben Goodger (Google) wrote:
> you can use a ternary here, it should fit on one line
> 
> return queue_events_ ? ui::ER_ASYNC : ui::ER_UNHANDLED;

Done.

http://codereview.chromium.org/10964051/diff/1038/ui/base/events/event_consta...
File ui/base/events/event_constants.h (right):

http://codereview.chromium.org/10964051/diff/1038/ui/base/events/event_consta...
ui/base/events/event_constants.h:107: ER_ASYNC     = 1 << 2,  // The event will
be processed asynchronously. The
On 2012/09/26 19:42:48, Ben Goodger (Google) wrote:
> Can you tell me how 'asynchronously' works and what this return code would be
> interpreted by the caller?

Right now, ASYNC is only used for touch-events, and this is returned only by
RenderWidgetHostViewAura. (I don't think there will be any other places that
will do this in the future)

For each touch-event that is processed as ASYNC, the RootWindow adds it in a
queue in the GestureRecognizer. For each such ASYNC touch event, the RWHVA calls
RootWindow::AdvanceQueuedTouchEvent asynchronously (after it receives an ACK
from renderer/WebKit). At this point, the GR removes the event from the queue
and processes it (and may generate gesture events, which are then dispatched by
the RootWindow).

There is plan to move the touch-event queue out of the GR and into content/,
since that will allow other platforms (e.g. android) to use the same queueing
code: crbug.com/138153. Once that happens, this ER_SYNC will no longer be
necessary.

http://codereview.chromium.org/10964051/diff/1038/ui/views/widget/desktop_nat...
File ui/views/widget/desktop_native_widget_aura.cc (right):

http://codereview.chromium.org/10964051/diff/1038/ui/views/widget/desktop_nat...
ui/views/widget/desktop_native_widget_aura.cc:442: case
ui::TOUCH_STATUS_UNKNOWN:
On 2012/09/26 19:42:48, Ben Goodger (Google) wrote:
> should you have a function in ui/base/events that has this switch statement?
> i've seen it a couple of times in this cl.

Done.

[Ben Goodger (Google), 2012-09-27 15:53:46]

lgtm


On Wed, Sep 26, 2012 at 2:26 PM, <sadrul@chromium.org> wrote:

>
> http://codereview.chromium.**org/10964051/diff/1038/ui/**
>
aura/gestures/gesture_**recognizer_unittest.cc<http://codereview.chromium.org/10964051/diff/1038/ui/aura/gestures/gesture_recognizer_unittest.cc>
> File ui/aura/gestures/gesture_**recognizer_unittest.cc (right):
>
> http://codereview.chromium.**org/10964051/diff/1038/ui/**
>
aura/gestures/gesture_**recognizer_unittest.cc#**newcode293<http://codereview.chromium.org/10964051/diff/1038/ui/aura/gestures/gesture_recognizer_unittest.cc#newcode293>
> ui/aura/gestures/gesture_**recognizer_unittest.cc:293: return
> ui::ER_ASYNC;
> On 2012/09/26 19:42:48, Ben Goodger (Google) wrote:
>
>> you can use a ternary here, it should fit on one line
>>
>
>  return queue_events_ ? ui::ER_ASYNC : ui::ER_UNHANDLED;
>>
>
> Done.
>
>
> http://codereview.chromium.**org/10964051/diff/1038/ui/**
>
base/events/event_constants.h<http://codereview.chromium.org/10964051/diff/1038/ui/base/events/event_constants.h>
> File ui/base/events/event_**constants.h (right):
>
> http://codereview.chromium.**org/10964051/diff/1038/ui/**
>
base/events/event_constants.h#**newcode107<http://codereview.chromium.org/10964051/diff/1038/ui/base/events/event_constants.h#newcode107>
> ui/base/events/event_**constants.h:107: ER_ASYNC     = 1 << 2,  // The
> event will be processed asynchronously. The
> On 2012/09/26 19:42:48, Ben Goodger (Google) wrote:
>
>> Can you tell me how 'asynchronously' works and what this return code
>>
> would be
>
>> interpreted by the caller?
>>
>
> Right now, ASYNC is only used for touch-events, and this is returned
> only by RenderWidgetHostViewAura. (I don't think there will be any other
> places that will do this in the future)
>
> For each touch-event that is processed as ASYNC, the RootWindow adds it
> in a queue in the GestureRecognizer. For each such ASYNC touch event,
> the RWHVA calls RootWindow::**AdvanceQueuedTouchEvent asynchronously
> (after it receives an ACK from renderer/WebKit). At this point, the GR
> removes the event from the queue and processes it (and may generate
> gesture events, which are then dispatched by the RootWindow).
>
> There is plan to move the touch-event queue out of the GR and into
> content/, since that will allow other platforms (e.g. android) to use
> the same queueing code: crbug.com/138153. Once that happens, this
> ER_SYNC will no longer be necessary.
>
>
> http://codereview.chromium.**org/10964051/diff/1038/ui/**
>
views/widget/desktop_native_**widget_aura.cc<http://codereview.chromium.org/10964051/diff/1038/ui/views/widget/desktop_native_widget_aura.cc>
> File ui/views/widget/desktop_**native_widget_aura.cc (right):
>
> http://codereview.chromium.**org/10964051/diff/1038/ui/**
>
views/widget/desktop_native_**widget_aura.cc#newcode442<http://codereview.chromium.org/10964051/diff/1038/ui/views/widget/desktop_native_widget_aura.cc#newcode442>
> ui/views/widget/desktop_**native_widget_aura.cc:442: case
> ui::TOUCH_STATUS_UNKNOWN:
> On 2012/09/26 19:42:48, Ben Goodger (Google) wrote:
>
>> should you have a function in ui/base/events that has this switch
>>
> statement?
>
>> i've seen it a couple of times in this cl.
>>
>
> Done.
>
>
http://codereview.chromium.**org/10964051/<http://codereview.chromium.org/109...
>