Feature: Detach window

[lukas-w]

Allows detaching a window from LMMS's main window, making things like working on multiple screens easier.

Closes #1259

Quick demonstration:

Edit: This uses some Qt5-only features, so it's best to wait with merging this until we've switched (#2611).

[BaraMGB]

Wow! That's really awesome!

[karmux]

Very useful functionality especially when using multi-monitor setup! 👍

I played a little bit with it and found some bugs:

1. When detached instruments are maximized then all instruments stay maximized inside LMMS until LMMS runs. I think there shouldn't be maximize button and functionality for instrument windows at all.
2. Mixer, project notes and controller rack can't be closed once detached. Clicking on X-button does nothing.
3. Trying to close instrument when detached crashes LMMS every time.
4. Detaching any window and then clicking minimize freezes this window inside LMMS main window and the subwindow border icons/labels don't look correct. Expected functionality is to minimize detached window same way like main window.
5. Detaching any window and then clicking maximize maximizes it inside LMMS main window and scrolling main window too much to the right. Expected functionality is to maximize detached window same way like main window.

LMMS 1.2.0-rc2.153
(Linux x86_64, Qt 5.7.1, GCC 6.3.0 20170406)

[lukas-w]

@karmux Thanks for testing! I'll have a look at the issues you pointed out as soon as I find the time. I already noticed number 2 (X-button doesn't work), but couldn't find the cause.

[aerobinsonIV]

This is super useful!!

I can't seem to make a windows build of it though. The build seems to go without a hitch, but when I open the app, it doesn't have the detach button. This might be my own error, but maybe someone else should look into it.

I can confirm all the issues that @karmux pointed out. Also, getting the detached window back into lmms is a little unwieldy. I basically need to re-open the window (for exmaple, clicking the FX-Mixer button to re-attach the FX-Mixer). Not exactly a bug, but it would be useful if the minimize button reattached the window, or if there was another button entirely.

Good job, looking forward to be able to use this for major producing :)

[NickAcPT]

Sorry for the bump.
@Jousboxx I agree with you when you gave the idea to make the minimize button reattach the window into LMMS.
But, if they were going to add a button inside the window to attach it back, they would need to adjust the window's content to account for the button.
Also, if you were talking about adding a button to the title bar, that would be a bit complicated and hard to maintain.

PS: Sorry to bother...

[aerobinsonIV]

@NickAcPT Yeah, my idea is that since the minimize button reattaches, they wouldn't have to add another button. The minimize button on the main LMMS window should probably shrink all child windows so there is a way to minimize them.

[PhysSong]

This uses some Qt5-only features, so it's best to wait with merging this until we've switched

Now we've, so I think we can continue working on this.

When detached instruments are maximized then all instruments stay maximized inside LMMS until LMMS runs. I think there shouldn't be maximize button and functionality for instrument windows at all.

It's already fixed.

Mixer, project notes and controller rack can't be closed once detached. Clicking on X-button does nothing.

Trying to close instrument when detached crashes LMMS every time.

vstSubWin, ControllerDialog, EffectControlDialog, FxMixerView, SongEditor(this is fine because SongEditorWindow doesn't), ControllerRackView, ProjectNotes and IntrumentTrackWindow class overrides closeEvent and ignores close event. See #1495 (comment) for why we have such workarounds.

Detaching any window and then clicking minimize freezes this window inside LMMS main window and the subwindow border icons/labels don't look correct. Expected functionality is to minimize detached window same way like main window.

Detaching any window and then clicking maximize maximizes it inside LMMS main window and scrolling main window too much to the right. Expected functionality is to maximize detached window same way like main window.

I guess the event is propagated to SubWindow in some way. Installing an event filter which blocks propagation seems to fix it.

[PhysSong]

Found some more issues:

• Window size is not preserved when using some window manager on X11(compiz on Ubuntu 18.04, unity session in my case). There's a known issue with frameGeometry on X11 so I'm not sure if we can work around this when attaching. It's from the difference between widget's size and subwindow's size.
• When switching instrument, detached windows get attached automatically.

[PhysSong]

if the minimize button reattached the window, or if there was another button entirely.

If the minimize button is used for attaching, wouldn't it be confusing? Also, I can't find platform-independent way to add such a button to the title bar unless we create a custom window class which would be quite difficult. There's an easier workaround, wrapping window content and window controls in a layout. It might be a little bit ugly, but it's easy.

@lukas-w may I continue this work?

[lukas-w]

@lukas-w may I continue this work?

Go for it. 👍

[PhysSong]

Fixed almost all bugs reported by @karmux. As a side effects, minimize button doesn't re-attach windows anymore. I can restore the behavior, but I think that might be confusing.
Bugs in #3532 (comment) still needs to be fixed.

[karmux]

@PhysSong thank you! During a quick test I couldn't reproduce any of my previously reported bugs.
While testing I discovered now that I can't close sample track instrument in detached mode. Maybe happens because I have #3866 merged.

[PhysSong]

Maybe happens because I have #3866 merged.

I think that's correct. IIRC I copied some code from instrument track and it had some issue(fixed in this PR).
When/If that one is merged, I will add a fix.

[lukas-w]

As a side effects, minimize button doesn't re-attach windows anymore.

It never did. This was just suggested by @Jousboxx in #3532 (comment).

[pwepwe973]

hello,
how to enable this option please?
thank you

[PhysSong]

@pwepwe973 This feature is in development and not a part of released versions. Sorry.

[pwepwe973]

thank you

@pwepwe973 This feature is in development and not a part of released versions. Sorry.

thank you for your message

[winniehell]

@PhysSong Can you please summarize the current state of this? Is it ready to be merged?

I'm willing to help get this finished if possible.

[PhysSong]

@PhysSong Can you please summarize the current state of this?

I unintentionally abandoned this one, but I can restart working on this.

Is it ready to be merged?

Not yet, mainly due to #3532 (comment).

[pwepwe973]

hello,

why not integrate this option in the new versions ?? for people with 2 screens

[Rossmaxx]

What's the status as of now? How about a rebase and bugfixes.

[pwepwe973]

I have never changed version since I kept this version with the detachment of the windows because I use the others on 2 screens, even if there are new things but I am not interested in WHAT INTERESTS ME IS TO BE ABLE TO WORK in a practical way with the 2 screens

[luzpaz]

What's blocking the rebase ?

[Rossmaxx]

merge conflicts maybe, and the fact that the author hasn't been here in a long time.

[messmerd]

@PhysSong Are you still working on this? If not, I can try getting it to a state where it's ready to merge.

[PhysSong]

@PhysSong Are you still working on this? If not, I can try getting it to a state where it's ready to merge.

@messmerd No, please feel free to take over.

[messmerd]

I fixed the bug that prevented detached editor windows (Song Editor, Piano Roll, etc.) from closing when "X" is clicked.

These are the known bugs that still remain:

• Detached microtuner config window doesn't close when "X" is clicked
• When switching instruments, detached windows get attached automatically
• The LMMS taskbar icon changes to the icon for the most recently detached window
• Some detached windows look really bad when maximized, so they should be prevented from maximizing if possible
• The "Add" button in the Controller Rack is not visible at first when attached