Create a factory to decode an SkBitmap from an SkData.

Create a factory to decode an SkBitmap from an SkData.

Add a test and a GM for the factory, and a PNG file for it to decode.
The PNG file is copyright-free, obtained from
http://openclipart.org/detail/29213/paper-plane-by-ddoo

In cmykjpeg, do not attempt to decode in the constructor, since it
currently crashes on Mac (if you provide the correct resource path).
Even when we fix this crash there is no need to do it in the
constructor, since we create all of the gms in order to
get their names (to determine whether to run them).

Committed: https://code.google.com/p/skia/source/detail?r=6618

[reed1, 2012-11-29 14:27:31]

At some point I anticipate wanting this to be a function-ptr or base-class, so
we can separate clients of decoders from implementations of decoders.

e.g.

typedef bool (*SkBitmapDecoderProc)(const SkData*, ...);

Maybe premature for this, but lets have some sketch of the larger picture of how
this will fit into pixelrefs and caches.

https://codereview.appspot.com/6847122/diff/1/include/images/SkBitmapFactory.h
File include/images/SkBitmapFactory.h (right):

https://codereview.appspot.com/6847122/diff/1/include/images/SkBitmapFactory....
include/images/SkBitmapFactory.h:20: */
Since the caller may already have a bitmap somewhere, can we take a
var-parameter for the output-bitmap?

bool (or error_code) DecodeBitmap(const SkData*, bool bounds, SkBitmap* output);

[Leon, 2012-11-29 17:53:06]

> At some point I anticipate wanting this to be a function-ptr or base-class, so
> we can separate clients of decoders from implementations of decoders.
> 
> e.g.
> 
> typedef bool (*SkBitmapDecoderProc)(const SkData*, ...);
> 
> Maybe premature for this, but lets have some sketch of the larger picture of
how
> this will fit into pixelrefs and caches.

I have added a comment to the header file.

https://codereview.appspot.com/6847122/diff/1/include/images/SkBitmapFactory.h
File include/images/SkBitmapFactory.h (right):

https://codereview.appspot.com/6847122/diff/1/include/images/SkBitmapFactory....
include/images/SkBitmapFactory.h:20: */
On 2012/11/29 14:27:32, reed1 wrote:
> Since the caller may already have a bitmap somewhere, can we take a
> var-parameter for the output-bitmap?
> 
> bool (or error_code) DecodeBitmap(const SkData*, bool bounds, SkBitmap*
output);

Done.

https://codereview.appspot.com/6847122/diff/5001/include/images/SkBitmapFacto...
File include/images/SkBitmapFactory.h (right):

https://codereview.appspot.com/6847122/diff/5001/include/images/SkBitmapFacto...
include/images/SkBitmapFactory.h:30: static bool DecodeBitmap(const SkData*,
SkBitmap*, bool boundsOnly = false);
Instead of passing a bool, should I just use SkImageDecoder::Mode?

[reed1, 2012-11-29 18:55:23]

parameter nit, but good start. lgtm

https://codereview.appspot.com/6847122/diff/5001/include/images/SkBitmapFacto...
File include/images/SkBitmapFactory.h (right):

https://codereview.appspot.com/6847122/diff/5001/include/images/SkBitmapFacto...
include/images/SkBitmapFactory.h:30: static bool DecodeBitmap(const SkData*,
SkBitmap*, bool boundsOnly = false);
On 2012/11/29 17:53:06, scroggo-work wrote:
> Instead of passing a bool, should I just use SkImageDecoder::Mode?

An enum is preferable to a bool, true. I wouldn't bring in SkImageDecoder.h for
that tho, lets just makeup a new one.

Small nit to put the bitmap* first or last, so that all of the input parameters
are on one side or the other.

[Leon, 2012-11-29 19:16:01]

https://codereview.appspot.com/6847122/diff/5001/include/images/SkBitmapFacto...
File include/images/SkBitmapFactory.h (right):

https://codereview.appspot.com/6847122/diff/5001/include/images/SkBitmapFacto...
include/images/SkBitmapFactory.h:30: static bool DecodeBitmap(const SkData*,
SkBitmap*, bool boundsOnly = false);
On 2012/11/29 18:55:23, reed1 wrote:
> On 2012/11/29 17:53:06, scroggo-work wrote:
> > Instead of passing a bool, should I just use SkImageDecoder::Mode?
> 
> An enum is preferable to a bool, true. I wouldn't bring in SkImageDecoder.h
for
> that tho, lets just makeup a new one.

Done.

> Small nit to put the bitmap* first or last, so that all of the input
parameters
> are on one side or the other.

Moved the bitmap first, so we can keep the optional parameter.