194459 - Can't drag links

Status: RESOLVED DUPLICATE of bug 200745

(Core :: DOM: Copy & Paste and Drag & Drop, defect, P2)

Description

[Koike Kazuhiko]

Drag of links sometimes fails.

If you move the mouse to drop the link somewhere, the linked text
should be highlighted, but sometimes it isn't. The mouse pointer
doesn't change.

Build: 2003022108-trunk/WinXP, 2003021905-trunk/Linux

Comment 1

[Koike Kazuhiko]

I think the fix of bug 103055 caused this bug.

Comment 2

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

Adding Cc: John Keiser.
John:
We think, this problem is another regression of bug 103055.
see this case.
http://bugzilla.mozilla.gr.jp/attachment.cgi?id=1506&action=view

you try this, you will be not able to drag.
1. Down a mouse button on yellow dot.
2. Drag to Outside the image.

but, drag to another side, you will be able to drag.

Comment 3

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

By a habit, this problem may be serious.
If you always down a button of mouse at a lower half of a line 
and you always drag to downward, you are not able to drag a link.

Comment 4

[John Keiser (jkeiser)]

OK, this regressed between the 14th and the 15th (which is when I checked in my
target fix), but backing out the retargeting does not fix this.  It's still
probably mine.

Comment 5

[Anthony Foiani]

I noticed that this got much worse between 1.3beta and 1.3 final,
on both Mac OSX and Linux x86.  CC'ing self and, by request,
timeless.

The particular patterns that I notice is that dragging a link
straight up usually doesn't work; if I click, drag to the side
a little bit, then move it up to the top (e.g. to a bookmark
folder on personal tool bar, or onto a tab) then it works.

Best guess is that it's timing/distance related (need to be
dragging on top of a link for a certain time or distance before
it's picked up for drag-and-drop).

Comment 6

[Jesse Ruderman]

*** Bug 199716 has been marked as a duplicate of this bug. ***

Comment 7

[Jeff Cooper]

I can't drag links from the URL locator bar to the "links" bar.  Try dragging
the little dinosaur... no luck.  Running XP, latest version of Mozilla, had this
happen on several computers.

Comment 8

[Jafe Mourner]

I think that this behavior occurs when the drag starts at the extreme edges of
the clickable area. For instance, on a text link, dragging from the bottom few
pixels down (on the underline of the link) will not result in grabbing the link.
Same with the top few pixels up, right few pixels right, and left few pixels left.

Comment 9

[Steve K]

I agree with comment #8; at least now, after reading this bug, I can see how to
work around it a bit.

I've noticed that ever since 1.3 final, I have about 50% success dragging links
under Linux, and about 25% success under MacOSX, with whatever my "normal"
procedure is.

Based on comment #8, I can reproduce this 100% by starting my drag near the edge
of the clickable region, and make it work 100% by starting towards the middle.

My uneducated guess is that the drag is being initiated by a mousemove event
with the mouse button down, and not by the initial mousedown event.  

So, if you drag starting near the edge, towards the edge, the first mousemove
event (with the mouse button down) mozilla sees is outside the clickable region,
even though the initial mousedown event is _inside_ the clickable region.  

This explanation also jibes with comment #5, since moving sideways is more
likely to get you a MouseMove event within the clickable region [ on the Mac, I
can't drag at all unless I have about a 25 pixel "runway" to initiate the drag
-- i.e. dragging up or down is impossible, unless I go very slow!]

And, probably the reason why it's so much worse for me under the Mac, may just
be the frequency in which that platform is getting mousemove events.

I've got to say that this is my #1 problem with Moz1.3 -- it's frustrating as
heck! and I'm sorry I didn't look into this more before 1.4a came out..

So, I can confirm this bug on 2 platforms: Linux/Xft RPM build, and MacOSX mach0
build of 1.3 final.

Comment 10

[John Keiser (jkeiser)]

I suspect this is fixed by bug 200745.  And only drivers can set blocking1.4b+.

Comment 11

[Simon Fraser [no longer active]]

Bug 200745 has more info and a patch. Duping.

*** This bug has been marked as a duplicate of 200745 ***