[Android WebView] Clamp Bitmap size to max. dimensions when drawing into a Canvas

[Android WebView] Clamp Bitmap size when it will be drawn into a Canvas.
    
    While the WebView GL path is still under development, we fall back
    to the SW path which uses a renders into a View-sized bitmap if a
    HW draw is requested. When drawing into a Canvas, there are
    maximum dimensions imposed on bitmaps that can be drawn into it,
    and when using a HW Canvas the limits are quite small (based on
    maximum GL texture size)
    
    This patch adds a size check on the bitmap we create if we intend
    it to be drawn into a Canvas. This means content may be cropped,
    but for testing some content is better than no content.

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=207747

[benm (inactive), 2013-06-20 10:17:32]

ptal!

[joth, 2013-06-20 17:26:08]

Thanks for fixing this up! Some suggestions to simplify the java class

https://codereview.chromium.org/17274013/diff/1/android_webview/java/src/org/...
File
android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java
(right):

https://codereview.chromium.org/17274013/diff/1/android_webview/java/src/org/...
android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java:26:
* Provides a Bitmap object with a given width and height used for auxiliary
rasterization.
// |canvas| is optional, and if supplied indicates the canvas this bitmap is
intended to draw onto. (But this method will not modify/draw to canvas at all)

https://codereview.chromium.org/17274013/diff/1/android_webview/java/src/org/...
android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java:30:
if (canvas != null && canvas.isHardwareAccelerated()) {
is the HW accelerated check needed here? We may as well have this check for all
canvases. (assuming SW canvas returns something sensible. The docs don't mention
any contract for 'no limit' so I guess they'll just return MAX_INT)

https://codereview.chromium.org/17274013/diff/1/android_webview/java/src/org/...
android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java:35:
// TODO(benm): Remove this code when HW work is ready.
...if we do leave this for all canvases, you can generalize the comment and
remove the TODO

https://codereview.chromium.org/17274013/diff/1/android_webview/java/src/org/...
android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java:40:
sMaximumBitmapHeight = canvas.getMaximumBitmapHeight();
nit: I think the statics are unnecessary - the perf gain will be negligible
compared to the cost of the createBitmap call below, and it just risks more
bleed over from one call to the next.

I'd just do
  width  = Math.min(width, canvas.getMaximumBitmapWidth())...

[benm (inactive), 2013-06-20 18:03:20]

thanks joth!

https://codereview.chromium.org/17274013/diff/1/android_webview/java/src/org/...
File
android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java
(right):

https://codereview.chromium.org/17274013/diff/1/android_webview/java/src/org/...
android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java:26:
* Provides a Bitmap object with a given width and height used for auxiliary
rasterization.
On 2013/06/20 17:26:08, joth wrote:
> // |canvas| is optional, and if supplied indicates the canvas this bitmap is
> intended to draw onto. (But this method will not modify/draw to canvas at all)

Done.

https://codereview.chromium.org/17274013/diff/1/android_webview/java/src/org/...
android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java:30:
if (canvas != null && canvas.isHardwareAccelerated()) {
On 2013/06/20 17:26:08, joth wrote:
> is the HW accelerated check needed here? We may as well have this check for
all
> canvases. (assuming SW canvas returns something sensible. The docs don't
mention
> any contract for 'no limit' so I guess they'll just return MAX_INT)

Looks like it will be 32766 in both dimensions for a SW canvas. Fair enough,
will generalise it.

https://codereview.chromium.org/17274013/diff/1/android_webview/java/src/org/...
android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java:35:
// TODO(benm): Remove this code when HW work is ready.
On 2013/06/20 17:26:08, joth wrote:
> ...if we do leave this for all canvases, you can generalize the comment and
> remove the TODO

Done.

https://codereview.chromium.org/17274013/diff/1/android_webview/java/src/org/...
android_webview/java/src/org/chromium/android_webview/JavaBrowserViewRendererHelper.java:40:
sMaximumBitmapHeight = canvas.getMaximumBitmapHeight();
Will do

[joth, 2013-06-20 18:42:25]

lgtm

[commit-bot: I haz the power, 2013-06-20 18:58:30]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/benm@chromium.org/17274013/8001

[commit-bot: I haz the power, 2013-06-21 07:20:55]

Change committed as 207747