When pasting clipboard content from Godot to other applications,
multiple SelectionRequest events are sent to Godot in order to access
the data. It could take a long time before the data is ready for the
other app because events were processed one by one on the main thread,
especially when Godot is unfocused and runs at low frequency.
With this change, SelectionRequest events are directly handled on the
separate event polling thread to minimize this delay.
This change also replaces clipboard_get() calls in SelectionRequest with
a direct access to internal_clipboard, since in this case we know Godot
is the owner of the clipboard content and it's not necessary to query
the x server for it.
This change makes keyboard inputs more responsive on Linux, especially
when the FPS is lower on slower configurations.
Polling events from the x server is done on a separate thread to avoid a
frame delay with inputs, due to first sending the event to the input
manager with XFilterEvent then processing the new event only on the next
frame.
Calls to Input Manager functions like XSetICFocus, XUnsetICFocus and
XSetICValues use a mutex, because they are polling events internally and
would otherwise interfere with our own thread process for polling events
which can cause a deadlock in some cases.
XUnsetICFocus is called instead of XSetICFocus on FocusOut events,
so the input manager can be properly notified of focus changes.
clipboard_get now uses a blocking call to poll for a specific event type
when waiting for a SelectionNotify event, instead of polling all events
and filtering them afterwards.
The engine now expects to emscripten FS to be setup and sync-ed before
main is called. This is exposed via `Module["initFS"]` which also allows
to setup multiple persistence paths (internal use only for now).
Additionally, FS syncing is done **once** for every loop if at least one
file in a persistent path was open for writing and closed, and if the FS
is not syncing already.
This should potentially fix issues reported by users where "autosave"
would not work on the web (never calling `syncfs` because of too many
writes).
Should fix#27009 where the DefaultProjectIcon was scaling
with the EDSCALE. Now it checks if the icon name is equal
to "DefaultProjectIcon" and sets the scale to 1.0 instead of
EDSCALE.
In order to allow selecting items by either holding left click, or click
to open and click again to select, mouse button release was invalidated
based on the amount of mouse motion.
This was causing issues in some scenarios where an item could be
selected while opening the menu if the mouse moved enough between button
press and release.
This case could happen in the language selection of the project manager,
especially on linux, because of the order and timing of the mouse
events on x11.
This change invalidates mouse release based on a timing condition rather
than moved distance to handle any case from the display server properly.
