shell.c: Prevent moving a window from more than one source

It was possible to start a move or resize with a pointer and then
start another move for the same surface with touch or a pointer from
another seat, which would make the window flicker around.  With this
commit, we now reject any attempts to move or resize a surface that is
currently grabbed.

diff --git a/src/shell.c b/src/shell.c
index 3d81e15..a5e653e 100644 (file)
--- a/src/shell.c
+++ b/src/shell.c
@@ -207,7 +207,7 @@ struct shell_surface {
        int32_t saved_x, saved_y;
        bool saved_position_valid;
        bool saved_rotation_valid;
-       int unresponsive;
+       int unresponsive, grabbed;
 
        struct {
                struct weston_transform transform;
@@ -375,6 +375,7 @@ shell_grab_start(struct shell_grab *grab,
        wl_signal_add(&shsurf->destroy_signal,
                      &grab->shsurf_destroy_listener);
 
+       shsurf->grabbed = 1;
        weston_pointer_start_grab(pointer, &grab->grab);
        if (shell->child.desktop_shell) {
                desktop_shell_send_grab_cursor(shell->child.desktop_shell,
@@ -389,8 +390,10 @@ shell_grab_start(struct shell_grab *grab,
 static void
 shell_grab_end(struct shell_grab *grab)
 {
-       if (grab->shsurf)
+       if (grab->shsurf) {
                wl_list_remove(&grab->shsurf_destroy_listener.link);
+               grab->shsurf->grabbed = 0;
+       }
 
        weston_pointer_end_grab(grab->grab.pointer);
 }
@@ -410,6 +413,7 @@ shell_touch_grab_start(struct shell_touch_grab *grab,
                      &grab->shsurf_destroy_listener);
 
        grab->touch = touch;
+       shsurf->grabbed = 1;
 
        weston_touch_start_grab(touch, &grab->grab);
        if (shell->child.desktop_shell)
@@ -420,8 +424,10 @@ shell_touch_grab_start(struct shell_touch_grab *grab,
 static void
 shell_touch_grab_end(struct shell_touch_grab *grab)
 {
-       if (grab->shsurf)
+       if (grab->shsurf) {
                wl_list_remove(&grab->shsurf_destroy_listener.link);
+               grab->shsurf->grabbed = 0;
+       }
 
        weston_touch_end_grab(grab->touch);
 }
@@ -1170,6 +1176,8 @@ surface_touch_move(struct shell_surface *shsurf, struct weston_seat *seat)
 
        if (shsurf->type == SHELL_SURFACE_FULLSCREEN)
                return 0;
+       if (shsurf->grabbed)
+               return 0;
 
        move = malloc(sizeof *move);
        if (!move)
@@ -1240,6 +1248,8 @@ surface_move(struct shell_surface *shsurf, struct weston_seat *seat)
        if (!shsurf)
                return -1;
 
+       if (shsurf->grabbed)
+               return 0;
        if (shsurf->type == SHELL_SURFACE_FULLSCREEN)
                return 0;