145350 - New methods in nsDragAndDrop.js

Status: RESOLVED FIXED

(Core :: DOM: Copy & Paste and Drag & Drop, defect)

Description

[Pierre Chanial]

Since bug 139471 has grown too much, I think it is a good idea to split it, so
that it receives enough exposure.
I need these APIs (still backward compatible) for my patch.
What's new?
1) dragEnter method that calls DNDobserver.onDragEnter(). Defined the same way
as dragExit.
2) It's now possible to specify a DNDobserver.canDrop() method that tells
whether or not the drop can occur. Mouse cursor changes are therefore
automatically handled.
Motivations:
- same observer structure as the tree one.
- dragSession.canDrop is now reliably available in the user observer. I don't
have time for the moment to investigate it further, but, yes, it is necessary to
check canDrop for the Drop, dragover, dragenter and dragexit methods.
- heavy simplification of the observer code.
3) corrected some pasted and missing headers

There may be some issue to discuss: if canDrop == false, I don't call drop. I
think it makes sense, but I wanted to draw your attention on it, since it is the
only non-backward compatible thing.

Patch will follow.
Pink, Ben,  could you review this patch, please?

Comment 1

[Pierre Chanial]

Attachment: Patch v1.0 (-wbu for review)

Comment 2

[Pierre Chanial]

Attachment: Patch v1.0

Comment 3

[Pierre Chanial]

Attachment: Patch v1.1

r=timeless with the following change in checkCanDrop:
bail earlier if this.mDragService.getCurrentSession() is not defined in order
to save an indentation.

Comment 4

[Ben Goodger (use ben at mozilla dot org for email)]

Comment on attachment 84926 [details] [diff] [review]
Patch v1.1

sr=[e-mail]

Comment 5

[Pierre Chanial]

fixed

Comment 6

[Pierre Chanial]

really fixed

Comment 7

[HJ]

Peirre, I'm not sure if this is the right bug but we can no longer drop on the
tabstrip. Is this caused by this patch or the one for bug
http://bugzilla.mozilla.org/show_bug.cgi?id=139471

Comment 8

[Pierre Chanial]

wfm linux build 2002 08 08. 
please file a new bug explaining what the problem is and assign it to me.