[mutter] ui: Use XI2 to fake GDK events

[Jasper St. Pierre <jstpierre src gnome org>]

commit c1ac9d1dff0d851f2b35983a7789b22e17a05904
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Tue Nov 20 20:57:13 2012 -0500

    ui: Use XI2 to fake GDK events
    
    This removes our final dependency on Core Events, meaning
    we can remove support code for them soon.
    
    This commit is a bit ugly as it requires ui having a dependency on
    core, but this is already a hack, so this is thus a hack inside a
    hack, and two hacks make a right or however that goes.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=688779

 src/ui/ui.c |   94 +++++++++++++++++++++++++++++++++++-----------------------
 1 files changed, 57 insertions(+), 37 deletions(-)
---
diff --git a/src/ui/ui.c b/src/ui/ui.c
index 097b204..e161d26 100644
--- a/src/ui/ui.c
+++ b/src/ui/ui.c
@@ -78,6 +78,18 @@ meta_ui_get_screen_number (void)
   return gdk_screen_get_number (gdk_screen_get_default ());
 }
 
+/* For XInput2 */
+#include "display-private.h"
+
+static gboolean
+is_input_event (XEvent *event)
+{
+  MetaDisplay *display = meta_get_display ();
+
+  return (event->type == GenericEvent &&
+          event->xcookie.extension == display->xinput_opcode);
+}
+
 /* We do some of our event handling in frames.c, which expects
  * GDK events delivered by GTK+.  However, since the transition to
  * client side windows, we can't let GDK see button events, since the
@@ -103,25 +115,33 @@ maybe_redirect_mouse_event (XEvent *xevent)
   GdkEvent *gevent;
   GdkWindow *gdk_window;
   Window window;
+  XIEvent *xev;
+  XIDeviceEvent *xev_d;
+  XIEnterEvent *xev_e;
+
+  if (!is_input_event (xevent))
+    return FALSE;
 
-  switch (xevent->type)
+  xev = (XIEvent *) xevent->xcookie.data;
+
+  switch (xev->evtype)
     {
-    case ButtonPress:
-    case ButtonRelease:
-      window = xevent->xbutton.window;
-      break;
-    case MotionNotify:
-      window = xevent->xmotion.window;
+    case XI_ButtonPress:
+    case XI_ButtonRelease:
+    case XI_Motion:
+      xev_d = (XIDeviceEvent *) xev;
+      window = xev_d->event;
       break;
-    case EnterNotify:
-    case LeaveNotify:
-      window = xevent->xcrossing.window;
+    case XI_Enter:
+    case XI_Leave:
+      xev_e = (XIEnterEvent *) xev;
+      window = xev_e->event;
       break;
     default:
       return FALSE;
     }
 
-  gdisplay = gdk_x11_lookup_xdisplay (xevent->xany.display);
+  gdisplay = gdk_x11_lookup_xdisplay (xev->display);
   ui = g_object_get_data (G_OBJECT (gdisplay), "meta-ui");
   if (!ui)
     return FALSE;
@@ -140,11 +160,11 @@ maybe_redirect_mouse_event (XEvent *xevent)
   if (gdk_display_device_is_grabbed (gdisplay, gdevice))
     return FALSE;
 
-  switch (xevent->type)
+  switch (xev->evtype)
     {
-    case ButtonPress:
-    case ButtonRelease:
-      if (xevent->type == ButtonPress)
+    case XI_ButtonPress:
+    case XI_ButtonRelease:
+      if (xev_d->evtype == XI_ButtonPress)
         {
           GtkSettings *settings = gtk_settings_get_default ();
           int double_click_time;
@@ -155,11 +175,11 @@ maybe_redirect_mouse_event (XEvent *xevent)
                         "gtk-double-click-distance", &double_click_distance,
                         NULL);
 
-          if (xevent->xbutton.button == ui->button_click_number &&
-              xevent->xbutton.window == ui->button_click_window &&
-              xevent->xbutton.time < ui->button_click_time + double_click_time &&
-              ABS (xevent->xbutton.x - ui->button_click_x) <= double_click_distance &&
-              ABS (xevent->xbutton.y - ui->button_click_y) <= double_click_distance)
+          if (xev_d->detail == ui->button_click_number &&
+              xev_d->event == ui->button_click_window &&
+              xev_d->time < ui->button_click_time + double_click_time &&
+              ABS (xev_d->event_x - ui->button_click_x) <= double_click_distance &&
+              ABS (xev_d->event_y - ui->button_click_y) <= double_click_distance)
             {
               gevent = gdk_event_new (GDK_2BUTTON_PRESS);
 
@@ -168,11 +188,11 @@ maybe_redirect_mouse_event (XEvent *xevent)
           else
             {
               gevent = gdk_event_new (GDK_BUTTON_PRESS);
-              ui->button_click_number = xevent->xbutton.button;
-              ui->button_click_window = xevent->xbutton.window;
-              ui->button_click_time = xevent->xbutton.time;
-              ui->button_click_x = xevent->xbutton.x;
-              ui->button_click_y = xevent->xbutton.y;
+              ui->button_click_number = xev_d->detail;
+              ui->button_click_window = xev_d->event;
+              ui->button_click_time = xev_d->time;
+              ui->button_click_x = xev_d->event_x;
+              ui->button_click_y = xev_d->event_y;
             }
         }
       else
@@ -181,25 +201,25 @@ maybe_redirect_mouse_event (XEvent *xevent)
         }
 
       gevent->button.window = g_object_ref (gdk_window);
-      gevent->button.button = xevent->xbutton.button;
-      gevent->button.time = xevent->xbutton.time;
-      gevent->button.x = xevent->xbutton.x;
-      gevent->button.y = xevent->xbutton.y;
-      gevent->button.x_root = xevent->xbutton.x_root;
-      gevent->button.y_root = xevent->xbutton.y_root;
+      gevent->button.button = xev_d->detail;
+      gevent->button.time = xev_d->time;
+      gevent->button.x = xev_d->event_x;
+      gevent->button.y = xev_d->event_y;
+      gevent->button.x_root = xev_d->root_x;
+      gevent->button.y_root = xev_d->root_y;
 
       break;
-    case MotionNotify:
+    case XI_Motion:
       gevent = gdk_event_new (GDK_MOTION_NOTIFY);
       gevent->motion.type = GDK_MOTION_NOTIFY;
       gevent->motion.window = g_object_ref (gdk_window);
       break;
-    case EnterNotify:
-    case LeaveNotify:
-      gevent = gdk_event_new (xevent->type == EnterNotify ? GDK_ENTER_NOTIFY : GDK_LEAVE_NOTIFY);
+    case XI_Enter:
+    case XI_Leave:
+      gevent = gdk_event_new (xev_e->evtype == XI_Enter ? GDK_ENTER_NOTIFY : GDK_LEAVE_NOTIFY);
       gevent->crossing.window = g_object_ref (gdk_window);
-      gevent->crossing.x = xevent->xcrossing.x;
-      gevent->crossing.y = xevent->xcrossing.y;
+      gevent->crossing.x = xev_e->event_x;
+      gevent->crossing.y = xev_e->event_y;
       break;
     default:
       g_assert_not_reached ();