Provide an override for Webview drop effect....

Provide an override for Webview drop effect.

Used for gears file drag & drop in chrome, provide a setter api to override the
default webview drop effect.  If gears overrides the drop_effect, then either a
"copy" or "none" cursor is shown to the user.  Otherwise, the drop effect shown
is the default for the webview (controlled by WebKit).

Also remove a TODO: during drag and drop, remember the drop accept state of the
webview (in drag enter, drag over).  Use that to prevent drops on webviews that
can't accept the drop data.

BUG=7995

[tony, 2009-04-20 17:30:08]

http://codereview.chromium.org/67297/diff/1/2
File webkit/glue/webview.h (right):

http://codereview.chromium.org/67297/diff/1/2#newcode211
Line 211: virtual bool SetDropEffect(bool accept) = 0;
Nit: Can you add a comment describing how you use this method?

http://codereview.chromium.org/67297/diff/1/4
File webkit/glue/webview_impl.cc (right):

http://codereview.chromium.org/67297/diff/1/4#newcode1703
Line 1703: if (!drop_accept_)  // IPC RACE CONDITION: do not allow this drop.
Can you elaborate on this comment more?  It would be nice to describe the race
condition here.

http://codereview.chromium.org/67297/diff/1/4#newcode1730
Line 1730: drop_effect_ = accept ? 1 : -1;
I'm confused what values drop_effect_ can have and what they mean.  You
initialize to 0, then you assign it 1 or -1.  Can this be an enum?

[noel.gordon_gmail.com, 2009-04-21 18:20:12]

new snapshot uploaded.

http://codereview.chromium.org/67297/diff/1/2
File webkit/glue/webview.h (right):

http://codereview.chromium.org/67297/diff/1/2#newcode211
Line 211: virtual bool SetDropEffect(bool accept) = 0;
done.  comments added for both these drag target helper methods.

http://codereview.chromium.org/67297/diff/1/4
File webkit/glue/webview_impl.cc (right):

http://codereview.chromium.org/67297/diff/1/4#newcode1703
Line 1703: if (!drop_accept_)  // IPC RACE CONDITION: do not allow this drop.
Done.

http://codereview.chromium.org/67297/diff/1/4#newcode1730
Line 1730: drop_effect_ = accept ? 1 : -1;
On 2009/04/20 17:30:08, tony wrote:
Fair call, made it an enum.

[tony, 2009-04-21 18:26:28]

LGTM.  I will commit this and fix the nit while I'm committing it.  Thanks!

http://codereview.chromium.org/67297/diff/3001/3003
File webkit/glue/webview_impl.h (right):

http://codereview.chromium.org/67297/diff/3001/3003#newcode331
Line 331: DROP_EFFECT_DEFAULT = 0, DROP_EFFECT_COPY, DROP_EFFECT_NONE
Nit: one value per line (that's what we do everywhere else we have an enum).

[noel.gordon_gmail.com, 2009-04-21 18:37:37]

On 2009/04/21 18:26:28, tony wrote:
> LGTM.  I will commit this and fix the nit while I'm committing it.  Thanks!
> 
> http://codereview.chromium.org/67297/diff/3001/3003
> File webkit/glue/webview_impl.h (right):
> 
> http://codereview.chromium.org/67297/diff/3001/3003#newcode331
> Line 331: DROP_EFFECT_DEFAULT = 0, DROP_EFFECT_COPY, DROP_EFFECT_NONE
> Nit: one value per line (that's what we do everywhere else we have an enum).
OK thanks tony.

[tony, 2009-04-22 00:13:00]

Committed in r14162.