Add TransferMode to dart:sky, and use it instead of passing ints around.

Add TransferMode to dart:sky, and use it instead of passing ints around.

Also use Point in place of passing 2 ints to the DrawLooper API.

R=eseidel@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/c2ace8a3e256e2f78e2ec1f7e1001ef47e2f5983

[Matt Perry, 2015-06-01 21:45:26]

mpcomplete@chromium.org changed reviewers:
+ eseidel@chromium.org

[eseidel, 2015-06-02 00:22:18]

lgtm

This is gorgeous.  Excepting the ugly fake-enum.

https://codereview.chromium.org/1158883004/diff/60001/sky/engine/core/paintin...
File sky/engine/core/painting/TransferMode.dart (right):

https://codereview.chromium.org/1158883004/diff/60001/sky/engine/core/paintin...
sky/engine/core/painting/TransferMode.dart:15: static const TransferMode
clearMode = const TransferMode(0);
Oh man.  We are gonna want some autogeneration or DSL-style assistance for these
blocks in the future.  Dart doesn't have a more concise way to write enums?

https://codereview.chromium.org/1158883004/diff/60001/sky/engine/core/paintin...
File sky/engine/core/painting/TransferMode.h (right):

https://codereview.chromium.org/1158883004/diff/60001/sky/engine/core/paintin...
sky/engine/core/painting/TransferMode.h:16: class TransferMode {
A bit strange that we can't just typedef this.  More bindings generation tricks
for a later time I guess. :)

[abarth-chromium, 2015-06-02 00:24:40]

abarth@chromium.org changed reviewers:
+ abarth@chromium.org

[abarth-chromium, 2015-06-02 00:24:41]

https://codereview.chromium.org/1158883004/diff/60001/sky/engine/core/paintin...
File sky/engine/core/painting/TransferMode.dart (right):

https://codereview.chromium.org/1158883004/diff/60001/sky/engine/core/paintin...
sky/engine/core/painting/TransferMode.dart:15: static const TransferMode
clearMode = const TransferMode(0);
On 2015/06/02 at 00:22:17, eseidel wrote:
> Oh man.  We are gonna want some autogeneration or DSL-style assistance for
these blocks in the future.  Dart doesn't have a more concise way to write
enums?

Dart has support for enums.  Maybe we just need a good way to access them via
the DarVM API?

[Matt Perry, 2015-06-02 18:28:54]

https://codereview.chromium.org/1158883004/diff/60001/sky/engine/core/paintin...
File sky/engine/core/painting/TransferMode.dart (right):

https://codereview.chromium.org/1158883004/diff/60001/sky/engine/core/paintin...
sky/engine/core/painting/TransferMode.dart:15: static const TransferMode
clearMode = const TransferMode(0);
On 2015/06/02 00:24:40, abarth wrote:
> On 2015/06/02 at 00:22:17, eseidel wrote:
> > Oh man.  We are gonna want some autogeneration or DSL-style assistance for
> these blocks in the future.  Dart doesn't have a more concise way to write
> enums?
> 
> Dart has support for enums.  Maybe we just need a good way to access them via
> the DarVM API?

I could use enums for this. They have 2 disadvantages:

1. You can't specify the enum values. They always start from 0 and increment by
1.
2. I can't figure out how to create an enum in C++ given an integer.

Neither are relevant here. #1 is fine because these values happen to follow that
pattern anyway. #2 is fine because we don't return a TransferMode from C++ to
Dart anywhere.

I can change to enums if you think it's better. I went with this way because it
seemed more flexible.

https://codereview.chromium.org/1158883004/diff/60001/sky/engine/core/paintin...
File sky/engine/core/painting/TransferMode.h (right):

https://codereview.chromium.org/1158883004/diff/60001/sky/engine/core/paintin...
sky/engine/core/painting/TransferMode.h:16: class TransferMode {
On 2015/06/02 00:22:18, eseidel wrote:
> A bit strange that we can't just typedef this.  More bindings generation
tricks
> for a later time I guess. :)

We can't because C++ doesn't have strong typedefs - it'd be a typedef to an
enum, so the compiler would just use the int32-version of DartConverter.

[eseidel, 2015-06-02 18:31:13]

ok, lgtm.  Perhaps we need to file a Dart improvement request or whatever it's
called about having enums which don't start at 0.

[Matt Perry, 2015-06-02 19:03:47]

Committed patchset #5 (id:80001) manually as
c2ace8a3e256e2f78e2ec1f7e1001ef47e2f5983 (presubmit successful).