Prevent a user from hiding the shelf via a gesture when there are no visible windows

- Prevent a user from hiding the shelf via a gesture when there are no visible windows
- Ignore the mouse position if mouse events are disabled (this is the case when the user is interacting with the device via touch)

BUG=268209
TEST=ShelfLayoutManagerTest.GestureDrag

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=216879

[pkotwicz, 2013-08-04 23:38:00]

sadrul@, PTAL

[sadrul, 2013-08-06 18:46:43]

The more desired behaviour would be to drag the shelf with the gesture, but at
the end of the drag, animate the shelf back up if there is no window.

[pkotwicz, 2013-08-08 23:51:36]

Thank you for your comments.
The good news, I now have the behavior you outlined. The bad news, I am
spreading it out over two CLs.

I will be posting the second CL shortly. The second CL makes
ShelfLayoutManager::CompleteGestureDrag() and
ShelfLayoutManager::CancelGestureDrag(). That involves making
ShelfLayoutManager::SetState() and ShelfLayoutManager::LayoutShelf() share code.

[pkotwicz, 2013-08-09 00:04:34]

https://codereview.chromium.org/22121002/diff/12001/ash/shelf/shelf_layout_ma...
File ash/shelf/shelf_layout_manager.cc (left):

https://codereview.chromium.org/22121002/diff/12001/ash/shelf/shelf_layout_ma...
ash/shelf/shelf_layout_manager.cc:574: // It's possible for SetState() when a
window becomes maximized but the state
This comment is outdated. State::window_state now exists

https://codereview.chromium.org/22121002/diff/12001/ash/shelf/shelf_layout_ma...
ash/shelf/shelf_layout_manager.cc:639: if (state.visibility_state ==
SHELF_AUTO_HIDE &&
To the extent of my understanding this is dead code (and always has been).
ShelfLayoutManager::GetShelfBackgroundType() does not take the auto hide state
into account.

I beleive that the intention of this code is to delay the shelf background
change when in maximized mode and transitioning from a visible shelf to an auto
hidden shelf. (Making that occur is not trivial so I am leaving that bug fix for
another time but am still removing the dead code).

https://codereview.chromium.org/22121002/diff/12001/ash/shelf/shelf_layout_ma...
File ash/shelf/shelf_layout_manager.cc (right):

https://codereview.chromium.org/22121002/diff/12001/ash/shelf/shelf_layout_ma...
ash/shelf/shelf_layout_manager.cc:645: } else {
Some house cleaning.

[sadrul, 2013-08-09 05:30:13]

https://codereview.chromium.org/22121002/diff/12001/ash/shelf/shelf_layout_ma...
File ash/shelf/shelf_layout_manager.cc (left):

https://codereview.chromium.org/22121002/diff/12001/ash/shelf/shelf_layout_ma...
ash/shelf/shelf_layout_manager.cc:670: UpdateShelfBackground(change_type);
This change, the change between newlines 645-652, oldlines 634-645 and 574-579
are not related to fixing this bug, right? This code is sufficiently brittle and
source of a lot of subtle bugs that this kind of clean-up is best done in a
separate CL, even if it looks innocuous.

[pkotwicz, 2013-08-09 06:33:04]

sadrul@, can you please take another look? I split out the miscellaneous parts
of this CL to https://codereview.chromium.org/22348004/

[pkotwicz, 2013-08-09 06:33:04]

sadrul@, can you please take another look? I split out the miscellaneous parts
of this CL to https://codereview.chromium.org/22348004/

[sadrul, 2013-08-09 06:42:49]

LGTM. Thanks!

[commit-bot: I haz the power, 2013-08-09 06:50:54]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pkotwicz@chromium.org/22121002/19001

[pkotwicz, 2013-08-09 06:51:58]

jamescook@ for OWNERS

[James Cook, 2013-08-09 16:54:34]

lgtm

[commit-bot: I haz the power, 2013-08-09 23:05:37]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pkotwicz@chromium.org/22121002/19001

[commit-bot: I haz the power, 2013-08-10 06:59:59]

Retried try job too often on win_rel for step(s) browser_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[commit-bot: I haz the power, 2013-08-10 15:23:40]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pkotwicz@chromium.org/22121002/19001

[commit-bot: I haz the power, 2013-08-10 17:14:45]

Change committed as 216879