[Spice-devel] [spice-gtk v3] Handle pause key correctly

[Frediano Ziglio]

Windows does not like Pause key sent with same scancodes as Break.
Although is the same physical key the two functions send two completely
different set of codes. On key press a E1 1D 45 sequence is generated
while on key release a E1 9D C5 is generated. Also some hardware
keyboards send press+release at the same time on key press (nothing on
release).
Tested with Linux and Windows clients.
Tested with Linux, Windows and DOS guests.
On Windows guest VK_PAUSE was not arriving correctly.

An additional send_pause function was added to avoid to change the
normal flow too much. This as the keymap table (generated from
src/keymaps.csv) can hold only one scancode while this key generate two
scancodes (ie E1-1D and 45) for each event.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 src/spice-widget.c | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

Changes from v2:
- add comment for GTK bug;
- extend commit message.

diff --git a/src/spice-widget.c b/src/spice-widget.c
index c7dd553..9020b07 100644
--- a/src/spice-widget.c
+++ b/src/spice-widget.c
@@ -1286,6 +1286,25 @@ static gboolean key_press_delayed(gpointer data)
     return FALSE;
 }
 
+static bool send_pause(SpiceDisplay *display, GdkEventType type)
+{
+    SpiceInputsChannel *inputs = display->priv->inputs;
+
+    /* Send proper scancodes. This will send same scancodes
+     * as hardware.
+     * The 0x21d is a sort of Third-Ctrl while
+     * 0x45 is the NumLock.
+     */
+    if (type == GDK_KEY_PRESS) {
+        spice_inputs_key_press(inputs, 0x21d);
+        spice_inputs_key_press(inputs, 0x45);
+    } else {
+        spice_inputs_key_release(inputs, 0x21d);
+        spice_inputs_key_release(inputs, 0x45);
+    }
+    return true;
+}
+
 static void send_key(SpiceDisplay *display, int scancode, SendKeyType type, gboolean press_delayed)
 {
     SpiceDisplayPrivate *d = display->priv;
@@ -1479,6 +1498,16 @@ static gboolean key_event(GtkWidget *widget, GdkEventKey *key)
     if (!d->inputs)
         return true;
 
+    if (key->keyval == GDK_KEY_Pause
+#ifdef G_OS_WIN32
+        /* for some reason GDK does not fill keyval for VK_PAUSE 
+         * See https://bugzilla.gnome.org/show_bug.cgi?id=769214
+         */
+        || key->hardware_keycode == VK_PAUSE
+#endif
+        ) {
+        return send_pause(display, key->type);
+    }
     if (!scancode)
         scancode = vnc_display_keymap_gdk2xtkbd(d->keycode_map, d->keycode_maplen,
                                                 key->hardware_keycode);
-- 
2.7.4