From afc46d8f3ba54c0a3b536d1ce05b3f8b4743cf17 Mon Sep 17 00:00:00 2001

From: "Daniel P. Berrange" <berrange@redhat.com>

Date: Fri, 13 Sep 2013 14:22:17 +0100

Subject: [PATCH] Only trigger grab sequence upon release

For

  https://bugzilla.redhat.com/show_bug.cgi?id=1007877

GTK-VNC uses the keyboard shortcut ctrl+alt to toggle inside/outside

the VM (aka release pointer). Now Gnome uses ctrl+alt+arrow_key to

switch virtual desktops. So these two shortcuts collide and gtk-vnc

will grab the key presses as soon as ctrl+alt is pressed and toogle

inside/outside the VM, which makes switching desktops impossible.

The solution is to only trigger the grab sequence when the user

releases the key. So if they press Ctrl+alt and then release it,

we trigger, but if they press Ctrl+alt+left-arrow we don't trigger

https://bugzilla.gnome.org/show_bug.cgi?id=685257

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

(cherry picked from commit af4fc65182f8a51d81fab2d7e46bc4a11a9da452)

---

 src/vncdisplay.c | 50 +++++++++++++++++++++++++++++++++++++++++---------

 1 file changed, 41 insertions(+), 9 deletions(-)

diff --git a/src/vncdisplay.c b/src/vncdisplay.c

index 37de008..51a6b0f 100644

--- a/src/vncdisplay.c

+++ b/src/vncdisplay.c

@@ -80,6 +80,7 @@ struct _VncDisplayPrivate

     size_t keycode_maplen;

     const guint16 *keycode_map;

+    gboolean vncgrabpending; /* Key sequence detected, waiting for release */

     VncGrabSequence *vncgrabseq; /* the configured key sequence */

     gboolean *vncactiveseq; /* the currently pressed keys */

 };

@@ -784,6 +785,17 @@ static gboolean motion_event(GtkWidget *widget, GdkEventMotion *motion)

 }

+/*

+ * Lets say the grab sequence of Ctrl_L + Alt_L

+ *

+ * We first need to detect when both Ctrl_L and Alt_L are pressed.

+ * When this happens we are "primed" to tigger.

+ *

+ * If any further key is pressed though, we unprime ourselves

+ *

+ * If any key is released while we are primed, then we

+ * trigger.

+ */ 

 static gboolean check_for_grab_key(GtkWidget *widget, int type, int keyval)

 {

     VncDisplayPrivate *priv = VNC_DISPLAY(widget)->priv;

@@ -793,23 +805,42 @@ static gboolean check_for_grab_key(GtkWidget *widget, int type, int keyval)

         return FALSE;

     if (type == GDK_KEY_RELEASE) {

+        gboolean active = priv->vncgrabpending;

         /* Any key release resets the whole grab sequence */

         memset(priv->vncactiveseq, 0,

                sizeof(gboolean)*priv->vncgrabseq->nkeysyms);

-

-        return FALSE;

+        priv->vncgrabpending = FALSE;

+        return active;

     } else {

+        gboolean setone = FALSE;

+

         /* Record the new key press */

-        for (i = 0 ; i < priv->vncgrabseq->nkeysyms ; i++)

-            if (priv->vncgrabseq->keysyms[i] == keyval)

+        for (i = 0 ; i < priv->vncgrabseq->nkeysyms ; i++) {

+            if (priv->vncgrabseq->keysyms[i] == keyval) {

                 priv->vncactiveseq[i] = TRUE;

+                setone = TRUE;

+            }

+        }

-        /* Return if any key is not pressed */

-        for (i = 0 ; i < priv->vncgrabseq->nkeysyms ; i++)

-            if (priv->vncactiveseq[i] == FALSE)

-                return FALSE;

+        if (setone) {

+            /* Return if any key is not pressed */

+            for (i = 0 ; i < priv->vncgrabseq->nkeysyms ; i++)

+                if (priv->vncactiveseq[i] == FALSE)

+                    return FALSE;

-        return TRUE;

+            /* All keys in grab seq are pressed, so prime

+             * to trigger on release

+             */

+            priv->vncgrabpending = TRUE;

+        } else {

+            /* Key not in grab seq, so must reset any pending

+             * grab keys we have */

+            memset(priv->vncactiveseq, 0,

+                   sizeof(gboolean)*priv->vncgrabseq->nkeysyms);

+            priv->vncgrabpending = FALSE;

+        }

+

+        return FALSE;

     }

 }

@@ -2238,6 +2269,7 @@ void vnc_display_set_pointer_grab(VncDisplay *obj, gboolean enable)

  */

 void vnc_display_set_grab_keys(VncDisplay *obj, VncGrabSequence *seq)

 {

+    obj->priv->vncgrabpending = FALSE;

     if (obj->priv->vncgrabseq) {

         vnc_grab_sequence_free(obj->priv->vncgrabseq);

         g_free(obj->priv->vncactiveseq);