aura: Start converting event-filters into event-handlers.

aura: Start converting event-filters into event-handlers.

As a first step, add pre-target and post-target event handlers in aura::Env. The
EventFilters added in the CompoundEventFilter will be eventually converted to
EventHandlers, and installed on the Env as pre- or post-target handlers. The
RootWindow makes sure that the correct event-handlers from the env gets added to
the appropriate handlers list. This will let us get rid of the event-dispatching
logic in CompoundEventFilter.

BUG=none

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=158037

[Ben Goodger (Google), 2012-09-20 21:29:48]

http://codereview.chromium.org/10960015/diff/5002/ui/aura/env.h
File ui/aura/env.h (right):

http://codereview.chromium.org/10960015/diff/5002/ui/aura/env.h#newcode85
ui/aura/env.h:85: void AddPreTargetEventHandler(ui::EventHandler* handler);
qq: could Env be an EventTarget with a NULL target_handler_?

[sadrul, 2012-09-20 22:33:30]

http://codereview.chromium.org/10960015/diff/5002/ui/aura/env.h
File ui/aura/env.h (right):

http://codereview.chromium.org/10960015/diff/5002/ui/aura/env.h#newcode85
ui/aura/env.h:85: void AddPreTargetEventHandler(ui::EventHandler* handler);
On 2012/09/20 21:29:48, Ben Goodger (Google) wrote:
> qq: could Env be an EventTarget with a NULL target_handler_?

Oh, very interesting. I made this change (RootWindow::GetParentTarget returns
Env, and the rest of the things are auto-taken care of). Thanks for the idea!

[sadrul, 2012-09-21 17:05:11]

ping!

[Ben Goodger (Google), 2012-09-21 18:09:18]

lgtm

http://codereview.chromium.org/10960015/diff/9001/ui/aura/root_window.cc
File ui/aura/root_window.cc (right):

http://codereview.chromium.org/10960015/diff/9001/ui/aura/root_window.cc#newc...
ui/aura/root_window.cc:815: void
RootWindow::ProcessPostTargetList(ui::EventHandlerList* list) {
seems like you could also nix this api now, since this was all it was used for.

[sadrul, 2012-09-21 19:05:36]

http://codereview.chromium.org/10960015/diff/9001/ui/aura/root_window.cc
File ui/aura/root_window.cc (right):

http://codereview.chromium.org/10960015/diff/9001/ui/aura/root_window.cc#newc...
ui/aura/root_window.cc:815: void
RootWindow::ProcessPostTargetList(ui::EventHandlerList* list) {
On 2012/09/21 18:09:18, Ben Goodger (Google) wrote:
> seems like you could also nix this api now, since this was all it was used
for.

Good point. But I am going to keep this for now since there is a test that uses
this API to make sure the handlers receive events in the correct phase. The test
can probably be made to work without this, though. I will clean up in a follow
up CL.