aura: Draw drop shadows under browsers and menus.

aura: Draw drop shadows under browsers and menus.

This is largely a port of the existing X window manager's
code for drawing shadows around windows.  It adds an
ImageGrid class for drawing a scaled 3x3 grid of gfx::Images
and a Shadow class (managed by aura_shell::ShadowController)
that uses ImageGrid to draw a shadow.  Shadows can be
disabled via --aura-no-shadows.

BUG=101977
TEST=added unit tests; also manually checked that shadows get drawn

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=111009

[Daniel Erat, 2011-11-15 01:05:04]

http://codereview.chromium.org/8555025/diff/1/chrome/browser/ui/views/frame/b...
File chrome/browser/ui/views/frame/browser_frame_aura.cc (right):

http://codereview.chromium.org/8555025/diff/1/chrome/browser/ui/views/frame/b...
chrome/browser/ui/views/frame/browser_frame_aura.cc:174:
GetNativeWindow()->SetShadowVisible(true);
Oshima recommended setting a new property for this, but as it's currently only
getting consumed by aura::Window, I figured that it's a bit cleaner to just add
a SetShadowVisible() method.

http://codereview.chromium.org/8555025/diff/1/views/widget/native_widget_aura.cc
File views/widget/native_widget_aura.cc (right):

http://codereview.chromium.org/8555025/diff/1/views/widget/native_widget_aura...
views/widget/native_widget_aura.cc:161: window_->SetShadowVisible(true);
Doing this from Views seems a bit gross to me.  Opinions about this?

[sky, 2011-11-15 04:49:13]

We've generally gone with very little features in aura itself, just the bare
minimum, and have the shell provide this level of functionality.
Ben might have some input here too.

  -Scott

http://codereview.chromium.org/8555025/diff/1/ui/aura/shadow.h
File ui/aura/shadow.h (right):

http://codereview.chromium.org/8555025/diff/1/ui/aura/shadow.h#newcode14
ui/aura/shadow.h:14: class Layer;
nit: don't indent this sort of thing.

http://codereview.chromium.org/8555025/diff/1/ui/aura/window.h
File ui/aura/window.h (right):

http://codereview.chromium.org/8555025/diff/1/ui/aura/window.h#newcode365
ui/aura/window.h:365: scoped_ptr<internal::Shadow> shadow_;
Would it work to make the shadow a transient child that is stacked below rather
than above the window?

http://codereview.chromium.org/8555025/diff/1/views/widget/native_widget_aura.cc
File views/widget/native_widget_aura.cc (right):

http://codereview.chromium.org/8555025/diff/1/views/widget/native_widget_aura...
views/widget/native_widget_aura.cc:161: window_->SetShadowVisible(true);
On 2011/11/15 01:05:04, Daniel Erat wrote:
> Doing this from Views seems a bit gross to me.  Opinions about this?

Why? This seems like the right place to me. The other option is to have a type
in window (or in a property on window), which doesn't feel right either.

[sky, 2011-11-15 04:50:40]

http://codereview.chromium.org/8555025/diff/1/views/widget/native_widget_aura.cc
File views/widget/native_widget_aura.cc (right):

http://codereview.chromium.org/8555025/diff/1/views/widget/native_widget_aura...
views/widget/native_widget_aura.cc:162: }
One more comment here. Are we really going to only have the shadow on menus?
Seems like we would want it normal windows too. That said, I'm sure going that
route would have serious performance implications. Maybe add the ability to turn
it on via a flag?

[Ben Goodger (Google), 2011-11-15 04:53:41]

Indeed. We do all our image-drawing and layout in views. e.g.
NonClientFrameView.

[Daniel Erat, 2011-11-15 15:54:34]

On 2011/11/15 04:53:41, Ben Goodger (Google) wrote:
> Indeed. We do all our image-drawing and layout in views. e.g.
> NonClientFrameView.

I didn't draw this as part of the frame since I don't think that we want a
view's shadow to be scaled when the view itself is scaled.

[Ben Goodger (Google), 2011-11-15 17:05:31]

I agree scaling the shadow in some situations may be undesirable, but it's
not clear what situations we're going to be scaling in yet.

The other gotcha is that the shadow is somewhat bound to the shape of the
window, and the shape of the window is defined by the frame graphics.
Consider the top rounded corners of the chrome window, the variable bubble
shape, etc.

-Ben

On Tue, Nov 15, 2011 at 7:54 AM, <[email protected]> wrote:

> On 2011/11/15 04:53:41, Ben Goodger (Google) wrote:
>
>> Indeed. We do all our image-drawing and layout in views. e.g.
>> NonClientFrameView.
>>
>
> I didn't draw this as part of the frame since I don't think that we want a
> view's shadow to be scaled when the view itself is scaled.
>
>
http://codereview.chromium.**org/8555025/<http://codereview.chromium.org/8555...
>

[Daniel Erat, 2011-11-15 17:52:58]

I'm looking into expanding WindowObserver's methods so this can happen in the
shell instead.

http://codereview.chromium.org/8555025/diff/1/ui/aura/shadow.h
File ui/aura/shadow.h (right):

http://codereview.chromium.org/8555025/diff/1/ui/aura/shadow.h#newcode14
ui/aura/shadow.h:14: class Layer;
On 2011/11/15 04:49:13, sky wrote:
> nit: don't indent this sort of thing.

Done.

http://codereview.chromium.org/8555025/diff/1/views/widget/native_widget_aura.cc
File views/widget/native_widget_aura.cc (right):

http://codereview.chromium.org/8555025/diff/1/views/widget/native_widget_aura...
views/widget/native_widget_aura.cc:162: }
On 2011/11/15 04:50:40, sky wrote:
> One more comment here. Are we really going to only have the shadow on menus?
> Seems like we would want it normal windows too. That said, I'm sure going that
> route would have serious performance implications. Maybe add the ability to
turn
> it on via a flag?

Yes, they're getting enabled in browser_frame_aura.cc.

[Daniel Erat, 2011-11-21 18:26:54]

Another look?  I've moved this into the shell.

[Ben Goodger (Google), 2011-11-21 18:53:14]

Nice! LGTM.