Use SkLerpXfermode to blend LabelButton images.

Use SkLerpXfermode to blend LabelButton images.

Use SkLerpXfermode in LabelButtonBorder::Paint.
This does linear interpolation between normal/hover images.
Re-enable animation for BlueButton instances.

BUG=239121
TEST=Button state animations on hover/unhover look right.
R=reed@google.com,sadrul@chromium.org
TBR=sky@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=217629

[msw, 2013-08-13 21:51:43]

Hey Mike, please take a look; thanks!
Sadrul, can you do a Views OWNERS review here?

[sadrul, 2013-08-14 10:59:46]

LGTM, assuming the canvas related changes in label_button_border.cc looks good
to reed

[reed1, 2013-08-14 13:33:56]

https://codereview.chromium.org/23058003/diff/2001/ui/views/controls/button/l...
File ui/views/controls/button/label_button_border.cc (right):

https://codereview.chromium.org/23058003/diff/2001/ui/views/controls/button/l...
ui/views/controls/button/label_button_border.cc:125:
canvas->sk_canvas()->saveLayer(NULL, NULL);
Not specific to this CL, but..

Skia definitely takes advantage of the optional rect parameter in saveLayer. If
you pass it, it will limit the size of the offscreen, which saves time both for
initialization and during the restore (when we 'compose' the layer).

Do we have this rect (or a conservative version of it?)

https://codereview.chromium.org/23058003/diff/2001/ui/views/controls/button/l...
ui/views/controls/button/label_button_border.cc:130:
paint.setXfermode(SkLerpXfermode::Create(animation->GetCurrentValue()));
Create returns an object of reference-count 1
setXfermode will increment that reference-count (to 2)
the paint's destructor will decrement it back to 1 .... LEAK

The fix is to call unref somehow on the xfermode itself.

either

paint.setXfermode(Create(...))->unref()

or

SkAutoTUnref<SkXfermode> mode(Create(...));
paint.setXfermode(mode);

will do the trick

https://codereview.chromium.org/23058003/diff/2001/ui/views/controls/button/l...
ui/views/controls/button/label_button_border.cc:131:
canvas->sk_canvas()->saveLayer(NULL, &paint);
Same comment here about the value of passing in a bounds-rect to saveLayer

[msw, 2013-08-14 16:17:10]

Thanks for the comments; please take another look!

https://codereview.chromium.org/23058003/diff/2001/ui/views/controls/button/l...
File ui/views/controls/button/label_button_border.cc (right):

https://codereview.chromium.org/23058003/diff/2001/ui/views/controls/button/l...
ui/views/controls/button/label_button_border.cc:125:
canvas->sk_canvas()->saveLayer(NULL, NULL);
On 2013/08/14 13:33:56, reed1 wrote:
> Not specific to this CL, but..
> 
> Skia definitely takes advantage of the optional rect parameter in saveLayer.
If
> you pass it, it will limit the size of the offscreen, which saves time both
for
> initialization and during the restore (when we 'compose' the layer).
> 
> Do we have this rect (or a conservative version of it?)

Done.

https://codereview.chromium.org/23058003/diff/2001/ui/views/controls/button/l...
ui/views/controls/button/label_button_border.cc:130:
paint.setXfermode(SkLerpXfermode::Create(animation->GetCurrentValue()));
On 2013/08/14 13:33:56, reed1 wrote:
> Create returns an object of reference-count 1
> setXfermode will increment that reference-count (to 2)
> the paint's destructor will decrement it back to 1 .... LEAK
> 
> The fix is to call unref somehow on the xfermode itself.
> 
> either
> 
> paint.setXfermode(Create(...))->unref()
> 
> or
> 
> SkAutoTUnref<SkXfermode> mode(Create(...));
> paint.setXfermode(mode);
> 
> will do the trick

Done. I too easily forgot how tricky using skia in chrome can be.

https://codereview.chromium.org/23058003/diff/2001/ui/views/controls/button/l...
ui/views/controls/button/label_button_border.cc:131:
canvas->sk_canvas()->saveLayer(NULL, &paint);
On 2013/08/14 13:33:56, reed1 wrote:
> Same comment here about the value of passing in a bounds-rect to saveLayer

Done.

[reed1, 2013-08-14 16:26:12]

lgtm

[commit-bot: I haz the power, 2013-08-14 17:03:00]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/msw@chromium.org/23058003/28001

[commit-bot: I haz the power, 2013-08-14 20:32:41]

Change committed as 217629