Support engine specific hotkey.

Support engine specific hotkey.

BUG=http://crosbug.com/2543
TEST=none

With this CL, each engine can specify one or more special activation hotkeys. This CL doesn't support customizing global hotkeys per engine.
I'd still prefer to customize the global hotkeys based on current locale rather than input method engine.




Add hotkeys property to IBusEngineDesc, so that each engine can specify their own special hotkeys. This is useful for input methods that have dedicated hotkeys, such as Japanese input methods, which has a dedicated hotkey key: Kana.

[Yusuke Sato, 2010-05-11 15:30:45]

(sorry for the terrible delay! Now all Tokyo members are back to work.)
Thanks for the patch! LGTM++

I'm fine with the current code, but let me ask two detailed questions:

1) I understood that with this patch we could support かな (Kana) and 英数 (Eisu)
keys, by adding Kana key to mozc and Eisu key to xkb:us::eng. But I'm still not
sure if this patch is sufficient to support Ctrl+space, which is common IME
toggle key among Chinese IME users. Can you let me know how we can support
Ctrl+space? Just add the hot-key to pinyin AND xkb:us::eng to simulate toggle?

2) Is it possible to upstream this change? This patch is backward-compatible and
does not break existing engines, right?

--Yusuke

[James Su, 2010-05-11 17:02:15]

在 2010年5月11日 上午8:30， <yusukes@chromium.org>写道：

> (sorry for the terrible delay! Now all Tokyo members are back to work.)
> Thanks for the patch! LGTM++
>
> I'm fine with the current code, but let me ask two detailed questions:
>
> 1) I understood that with this patch we could support かな (Kana) and 英数
> (Eisu)
> keys, by adding Kana key to mozc and Eisu key to xkb:us::eng. But I'm still
> not
> sure if this patch is sufficient to support Ctrl+space, which is common IME
> toggle key among Chinese IME users. Can you let me know how we can support
> Ctrl+space? Just add the hot-key to pinyin AND xkb:us::eng to simulate
> toggle?
>
I still don't have a good idea on how to support ctrl+space. Adding such
thing into engine may make things much more complicated. For now, I'd prefer
to have different sets of predefined global hotkeys for different locales,
but not sure if it's supported by current preferences architecture.


>
> 2) Is it possible to upstream this change? This patch is
> backward-compatible and
> does not break existing engines, right?
>
This patch adds a member to EngineDisc, so I not sure if it can maintain
backward-compatibility for all engines. I talked to Huang Peng, he would
like to consider this patch later.


>
> --Yusuke
>
>
> http://codereview.chromium.org/1702015/show
>