CLAP plugins don't receive keyboard input

[saberking]

I have noticed that CLAP plugins don't receive keyboard input at all. This happens on both Windows (Reaper and FL Studio) and Linux (Reaper).

The VST3s are working perfectly so I guess this is a bug in DPF's CLAP implementation. I will try to see if I can figure out how to fix it.

[dromer]

I can receive keyboard input in Cardinal.clap (running in carla-single) so this is not completely accurate, but I understand that there could still be issues in other hosts.

[saberking]

Just tried it out and I can confirm that CLAP keyboard input does indeed work in Carla.

[saberking]

OK, I have more information. I have tested this with both the DPF ImGui Template Plugin and with my own plugins based on that template.

Reaper+Linux, floating window:

• keyboard input doesn't work at all for ImGui plugins
• Cardinal works fine

Reaper+Linux, embedded window:

• ImGui plugin keyboard input works until I close the UI. On subsequent opens it doesn't work. But if I press 'A' then Reaper pops up the "Add Plugin" window and if I close that and then click once more in the box where I am trying to type then it works again. This process must be repeated each time I open the plugin UI.
• Cardinal works fine

Carla+Linux:

• All working fine

Reaper + Windows plugin or FL Studio + Windows plugin (both running in WINE):

• keyboard input doesn't work at all
• can't test Cardinal because it crashes instantly

From this I am guessing that Cardinal has some special workaround for making sure it always received keyboard input when required, but this workaround is not present in the ImGui Template Plugin.

EDIT: In Linux Reaper, clicking somewhere else in the Reaper window then clicking on the plugin UI again gets the keyboard focus back. But this doesn't help for WINE versions.

EDIT 2: It doesn't look like Cardinal does anything special to get keyboard input so I'm thinking now it is not a problem with DPF but with the ImGui widget.

EDIT 3: Even when I get the keyboard focused into the ImGui plugin, if I hover the mouse outside its window the keystrokes go to Reaper instead. As soon as I move the mouse back into the plugin window the keystrokes go to the plugin again. Cardinal does not have this problem.

[saberking]

OK well it seems to have fixed itself (mostly). As I was testing and adding logging statements throughout DPF to try to find out what was going on, the behaviour kept changing, seemingly randomly. There seems to be a large random element to this problem, maybe some weird caching in my build process or a bug in my OS? I have no idea. I am using QT Creator to build it, it has been working great until now, I don't know if this is anything to do with the problem I was experiencing.

Anyway, today the problem is different and much more understandable, and I have deleted all the build folders and rebuilt a few times and it no longer changes each time:

LINUX DAWS:

• Ardour/Carla: everything works fine.
• Reaper: Keyboard focus is not given to the plugin, whether VST2, VST3 or CLAP. To get the focus into the plugin it is necessary to do one of the following:
  -- call getWindow().focus(), which is what Cardinal does;
  -- or click outside the plugin window then inside it again.

WINDOWS DAWS with WINE:

• Reaper and FL Studio: VST3 works perfectly. CLAP never gets keyboard focus even if I click outside the plugin window and then inside it again. To make CLAP work, it is necessary to call getWindow().focus().

CONCLUSION:
If one wants one's plugin to work in Linux Reaper or wants Windows CLAP to work anywhere, it is necessary to call getWindow().focus(). Without this, the behaviour is different depending on host, OS and plugin format, which is not good.