2029052 - Cannot drag window by title bar when "Add Tab to Taskbar" is enabled

Status: RESOLVED DUPLICATE of bug 2016994

(Firefox :: Shell Integration, defect)

Description

[EBo]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:149.0) Gecko/20100101 Firefox/149.0

Steps to reproduce:

1. Enable the "Add Tab to Taskbar" feature (e.g., via browser.tabs.inTaskbar or the specific extension you are using).

2. Ensure the Firefox window is not maximized (restored down).

3. Click and hold the mouse on the empty space in the middle of the title bar.

4. Try to drag the window.

Actual results:

The window does not move. The drag action seems to be ignored or blocked, even though the cursor might change to a drag icon. I cannot reposition the window using the title bar.

Expected results:

The Firefox window should move and follow the mouse cursor, just like standard Windows behavior for dragging a window by its title bar.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Firefox::Tabbed Browser' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Duncan McIntosh [:dmcintosh]]

Attachment: example.png

Thanks for the report!

I'm curious what your web app window looks like. I've attached a screenshot of one of my web apps—is the place you were dragging inside the red area (if that even exists for you), or the blueish areas?

If you're using the builtin browser.taskbarTabs.enabled, can you also confirm whether clicking and dragging on the icon, or the empty space around the icon, works?

(If you're using something other than the builtin browser.taskbarTabs.enabled, does all empty space not work, or just the part in the middle?)

Comment 3

[[:anutrix]]

Facing same issue on latest Firefox 149.0.2 on Windows 11.

I'm curious what your web app window looks like. I've attached a screenshot of one of my web apps—is the place you were dragging inside the red area (if that even exists for you), or the blueish areas?

Yes. Drag works in blue area but does not work in red area. It does not work in any part for red area in taskbar tab windows.

If you're using the builtin browser.taskbarTabs.enabled, can you also confirm whether clicking and dragging on the icon, or the empty space around the icon, works?

browser.taskbarTabs.enabled is enabled. Dragging icon or around it works fine. Only the middle part is the issue.

Comment 4

[Duncan McIntosh [:dmcintosh]]

(In reply to [:anutrix] from comment #3)

Facing same issue on latest Firefox 149.0.2 on Windows 11.

I'm curious what your web app window looks like. I've attached a screenshot of one of my web apps—is the place you were dragging inside the red area (if that even exists for you), or the blueish areas?

Yes. Drag works in blue area but does not work in red area. It does not work in any part for red area in taskbar tab windows.

Right, that's what I'd expect. You're (definitely, given what you filed in bug 2030814) seeing a consequence of bug 2016994, where the visual size of the address bar is wrong but the area isn't draggable. (i.e., you're actually dragging on space reserved for the address bar!) I need to take another look at that soon.

I'll leave this bug open until :Ebo responds in case their issue is different.

Comment 5

[Dão Gottwald [:dao]]

Let's track this in bug 2016994.