compositor-x11: Generalize handling of event pairs

We need to look at the focus_in and keymap notify pair to correctly determine
the set of held down keys at focus in time, so generalize the handling
of event pairs in preparation for that.

diff --git a/compositor/compositor-x11.c b/compositor/compositor-x11.c
index 04eca07..fcf4fe1 100644 (file)
--- a/compositor/compositor-x11.c
+++ b/compositor/compositor-x11.c
@@ -381,11 +381,11 @@ x11_compositor_handle_event(int fd, uint32_t mask, void *data)
 {
        struct x11_compositor *c = data;
        struct x11_output *output;
-        xcb_generic_event_t *event;
+       xcb_generic_event_t *event, *prev;
        xcb_client_message_event_t *client_message;
        xcb_motion_notify_event_t *motion_notify;
        xcb_enter_notify_event_t *enter_notify;
-       xcb_key_press_event_t *key_press, *prev_release;
+       xcb_key_press_event_t *key_press, *key_release;
        xcb_button_press_event_t *button_press;
        xcb_keymap_notify_event_t *keymap_notify;
        xcb_focus_in_event_t *focus_in;
@@ -393,25 +393,36 @@ x11_compositor_handle_event(int fd, uint32_t mask, void *data)
        uint32_t *k;
        int i, set;
 
-       prev_release = NULL;
-        while (event = xcb_poll_for_event (c->conn), event != NULL) {
-               key_press = (xcb_key_press_event_t *) event;
-               if (prev_release &&
-                   (event->response_type & ~0x80) == XCB_KEY_PRESS &&
-                   prev_release->time == key_press->time) {
-                       free(prev_release);
-                       free(event);
-                       prev_release = NULL;
-                       continue;
-               } else if (prev_release) {
-                       notify_key(c->base.input_device,
-                                  prev_release->time,
-                                  prev_release->detail - 8, 0);
-                       free(prev_release);
-                       prev_release = NULL;
+       prev = NULL;
+       while (event = xcb_poll_for_event (c->conn), event != NULL) {
+               switch (prev ? prev->response_type & ~0x80 : 0x80) {
+               case XCB_KEY_RELEASE:
+                       key_release = (xcb_key_press_event_t *) prev;
+                       key_press = (xcb_key_press_event_t *) event;
+                       if ((event->response_type & ~0x80) == XCB_KEY_PRESS &&
+                           key_release->time == key_press->time) {
+                               /* Don't deliver the held key release
+                                * event or the new key press event. */
+                               free(event);
+                               free(prev);
+                               prev = NULL;
+                               continue;
+                       } else {
+                               /* Deliver the held key release now
+                                * and fall through and handle the new
+                                * key press below. */
+                               notify_key(c->base.input_device,
+                                          key_release->time,
+                                          key_release->detail - 8, 0);
+                               free(prev);
+                               prev = NULL;
+                               break;
+                       }
+               default:
+                       /* No previous event held */
+                       break;
                }
 
-
                switch (event->response_type & ~0x80) {
 
                case XCB_KEY_PRESS:
@@ -420,7 +431,7 @@ x11_compositor_handle_event(int fd, uint32_t mask, void *data)
                                   key_press->time, key_press->detail - 8, 1);
                        break;
                case XCB_KEY_RELEASE:
-                       prev_release = (xcb_key_press_event_t *) event;
+                       prev = event;
                        break;
                case XCB_BUTTON_PRESS:
                        button_press = (xcb_button_press_event_t *) event;
@@ -515,16 +526,20 @@ x11_compositor_handle_event(int fd, uint32_t mask, void *data)
                        break;
                }
 
-               if ((xcb_generic_event_t *) prev_release != event)
+               if (prev != event)
                        free (event);
        }
 
-       if (prev_release) {
-               key_press = (xcb_key_press_event_t *) prev_release;
+       switch (prev ? prev->response_type & ~0x80 : 0x80) {
+       case XCB_KEY_RELEASE:
+               key_release = (xcb_key_press_event_t *) prev;
                notify_key(c->base.input_device,
-                          prev_release->time, prev_release->detail - 8, 0);
-               free(prev_release);
-               prev_release = NULL;
+                          key_release->time, key_release->detail - 8, 0);
+               free(prev);
+               prev = NULL;
+               break;
+       default:
+               break;
        }
 }