766920 - Mouse cursor flicker when the dialog is shown from the third-party DLL

Status: RESOLVED INCOMPLETE

(Core :: General, defect)

Description

[Evgeny]

I use JS CTypes to launch a dialog from the third-party DLL.

When the dialog appears, I can see the mouse cursor flicker in the text edit areas

(I did some tests with the XPCOM binary and got the same problems with the mouse flicker)

The mouse cursor should have a "text-caret" shape and this shape should not change to the default pointer style.

This problem always happen to my webpage with the Facebook "Like" plugin installed. I created a lightweight XPI demo and a short movie demonstrating that problem.

This problem exists on Firefox 5 and Firefox 14. I did not perform any tests for the other versions.

Comment 1

[Evgeny]

I tested it with Firefox 12 and Firefox 13 and had the same problem.

Comment 2

[Evgeny]

Attachment: This archive contains the lightwieight XPI extension used to re-create this problem

Comment 3

[Evgeny]

This is a movie demonstrating the problem: http://screenshot-program.com/dloads/cursor_flicker_bug.wmv

Comment 4

[Evgeny]

I tested different DLLs and dialogs on 3 my PCs and this bug exists everywhere

Comment 5

[Jorge Villalobos [:jorgev] (he/him)]

So, the dialog is opened from a library that is run using JS ctypes, and it only shows the cursor flickering when the current tab has a Facebook widget loaded in it? That's really bizarre...

Kris, can you confirm that this bug happens on Windows?

Comment 6

[Kris Maglione [:kmag]]

I can't test this, at the moment. I'd need to convince VirtualBox that I have a USB or floppy drive, which is proving a challenge. If you have an example which does not require this, let me know and I'll try it.

As for the behavior, I don't find it particularly odd given that you're opening a native window unknown to Firefox in the same process. It might be best to just launch it via rundll.

Comment 7

[Evgeny]

Jorge, cursor flickering can be also seen when the DLL form is executed at the moment of the page loading.

There's no cursor flicker if I add "alert('launching dll code now')".

Kris, do you need me to create another version of the extension with custom DLL so you don't need to convince VirtualBox? You can try installing FireShot and launching FireShot editor to see this bug. This is the extension in which I detected the bug first.

Comment 8

[Evgeny]

Just to make clear: there's no cursor flicker if I add "alert('launching dll code now')" prior to launching the form. Looks like this dialog does something that changes currently focused control, so it cannot modify the mouse cursor anymore.

Comment 9

[Kris Maglione [:kmag]]

Ok. I can confirm this with Fireshot. I think this belongs in Core > General rather than Firefox > Extension Compat.

Comment 10

[Jorge Villalobos [:jorgev] (he/him)]

Moving to Core > General.

Comment 11

[Eric Promislow]

Wondering if this is the same bug as 
Komodo http://bugs.activestate.com/show_bug.cgi?id=97604
Windows only -- in the save-as window, sometimes the cursor sometimes
blinks about 10-20 pixels to the right of the last character on
the file name field.

Comment 12

[Wayne Mery (:wsmwk)]

Reporter is gone.
OS no longer supported.

Comment 13

[Andrew McCreight [:mccr8]]

I think we can just close this. The specific scenario they were having trouble with is rather odd.