offer right-ctrl as a grab option

Add support for -ctrl-grab to use the right-ctrl button to grab/release
the mouse in SDL.

The multi-button ctrl-alt and ctrl-alt-shift grab buttons present an
accessibility problem to users who cannot press more than one button
at a time.

https://bugs.edge.launchpad.net/ubuntu/+source/qemu-kvm/+bug/237635

Signed-off-by: Dustin Kirkland <kirkland@canonical.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 11 insertions, 7 deletions

diff --git a/sdl.c b/sdl.c
index 42b6f37..034440f 100644
--- a/sdl.c
+++ b/sdl.c
@@ -414,10 +414,12 @@ static void sdl_update_caption(void)
     if (!vm_running)
         status = " [Stopped]";
     else if (gui_grab) {
-        if (!alt_grab)
-            status = " - Press Ctrl-Alt to exit grab";
-        else
+        if (alt_grab)
             status = " - Press Ctrl-Alt-Shift to exit grab";
+        else if (ctrl_grab)
+            status = " - Press Right-Ctrl to exit grab";
+        else
+            status = " - Press Ctrl-Alt to exit grab";
     }
 
     if (qemu_name) {
@@ -557,12 +559,14 @@ static void sdl_refresh(DisplayState *ds)
         case SDL_KEYDOWN:
         case SDL_KEYUP:
             if (ev->type == SDL_KEYDOWN) {
-                if (!alt_grab) {
-                    mod_state = (SDL_GetModState() & gui_grab_code) ==
-                                gui_grab_code;
-                } else {
+                if (alt_grab) {
                     mod_state = (SDL_GetModState() & (gui_grab_code | KMOD_LSHIFT)) ==
                                 (gui_grab_code | KMOD_LSHIFT);
+                } else if (ctrl_grab) {
+                    mod_state = (SDL_GetModState() & KMOD_RCTRL) == KMOD_RCTRL;
+                } else {
+                    mod_state = (SDL_GetModState() & gui_grab_code) ==
+                                gui_grab_code;
                 }
                 gui_key_modifier_pressed = mod_state;
                 if (gui_key_modifier_pressed) {