Unless the corresponding mouse down event was on our surface, we should
not be receiving the mouse up.
This is always the case on Wayland. On some other platforms,
SDL_CaptureMouse can be used to obtain input that happens outside the
Looking Glass surface, but Looking Glass does not make use of that
function.
We may want to process a mouse up if the corresponding mouse down
initiated a drag (e.g., of a window) that was released slightly outside
of the Looking Glass surface. Previously, Looking Glass would ignore the
mouse up, and the guest would be confused into thinking the button had
never been released, not ending the drag.
zwp_relative_pointer_manager_v1 and zwp_pointer_constraints_v1 are
supported by GNOME/KDE/sway (and most other compositors), but they are
not a required part of the protocol.
Some users also run software in one-off nested compositors like cage[0]
for an extra layer of isolation; cage, at least, does not support
pointer captures.
This commit makes Looking Glass warn when an optional protocol is
unsupported, and fail if a required one is missing. Pointer grab paths
have a new guard against the aforementioned protocols being missing.
[0]: https://github.com/Hjdskes/cage
We are actually getting mouse events directly from Wayland instead of going
through SDL, so we call app_updateCursorPos in pointer motion handlers and
swallow the SDL event.
Also removed parameters for app_handleMouseBasic as it relies exclusively on
absolute positions provided by app_updateCursorPos. Wayland does not give
you relative movements at all unless grabbed and passing absolute movements
is semantically incorrect.
Note that when the cursor is grabbed, movements are handled entirely through
relativePointerMotionHandler in wayland.c and does not go through
app_handleMouseBasic at all.
If the guest cursor state & position is unknown we can not rely on the
information to detect edge crossings. As such only allow cursor input if
LG is operating in capture mode.
Platforms such as Wayland have no abillity to warp the cursor, as such
can not operate in an always relative mode. This property allows
platforms to report the lack of warp support and prevent LG from
grabbing the pointer.
Some platforms such as Wayland need to set environment vairables before
SDL is initialized, as such this change detects the display server
before SDL has started and calls the new `earlyInit` method providing
the implementation an opportunity to set things up.
When capture mode is set if the cursor is not already in the view area
we need to force it to the state it would be if it were in view as
capture mode overrides all.
The pointer may not yet be in the view area so we should defer drawing
it until the mouse move handler determines that it's inside the view
area and turn it on itself.
As LG always operates in relitive mode, the actual pointer grab/ungrab
is managed by the move handler, as such setGrabQuiet should not alter
the grab/ungrab state of the local pointer.
The prototype for abs is int abs (int n), which implicitly casts floating
point values to integers. The correct function is fabs.
This commit allows the client to compile under clang.
gcc -Wimplicit-fallthrough only detects comments if they are immediately
preceded before the next label. Braces stops it from recognizing the
fallthrough comment.
-Wno-sign-compare is used to suppress warnings related to comparing signed
values with unsigned ones. It's too pedantic.
-Wunused-parameter is also too pedantic, especially since all parameters
have to be named in C.
Otherwise, -Wextra lets us catch bugs, such as x < 0 for unsigned x.
On gcc, we pass -Wimplicit-fallthrough=2 so it will recognize our fall
through comment.
This makes it a compile-time error to call a function that semantically
takes no parameters with a nonzero number of arguments.
Previously, such code would still compile, but risk blowing up the stack
if a compiler chose to use something other than caller-cleanup calling
conventions.
