[PATCH 2/2] ui/gtk: a new array param monitor to specify the target displays

[Dongwon Kim <dongwon.kim@intel.com>]

New integer array parameter, 'monitor' is for specifying the target
displays where individual QEMU windows are placed upon launching.

The array contains a series of numbers representing the monitor where
QEMU windows are placed.

Numbers in the array are mapped to QEMU windows like,

[1st detached window, 2nd detached window,.... Main window]

Usage example: -display gtk,monitor.0=0,monitor.1=1.....

Cc: Daniel P. Berrangé <berrange@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>
Signed-off-by: Dongwon Kim <dongwon.kim@intel.com>
---
 qapi/ui.json    |  7 ++++++-
 qemu-options.hx |  2 +-
 ui/gtk.c        | 32 +++++++++++++++++++++++++++++++-
 3 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/qapi/ui.json b/qapi/ui.json
index 11a827d10f..94546cfe84 100644
--- a/qapi/ui.json
+++ b/qapi/ui.json
@@ -1195,12 +1195,17 @@
 #               assuming the guest will resize the display to match
 #               the window size then.  Otherwise it defaults to "off".
 #               Since 3.1
+# @monitor:     Array of numbers, each of which represents physical
+#               monitor where individual QEMU window is placed in case
+#               there are multiple of them
+#               since 7.1
 #
 # Since: 2.12
 ##
 { 'struct'  : 'DisplayGTK',
   'data'    : { '*grab-on-hover' : 'bool',
-                '*zoom-to-fit'   : 'bool'  } }
+                '*zoom-to-fit'   : 'bool',
+                '*monitor'       : ['uint16']  } }
 
 ##
 # @DisplayEGLHeadless:
diff --git a/qemu-options.hx b/qemu-options.hx
index a664baaa18..c2523ae0da 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1943,7 +1943,7 @@ DEF("display", HAS_ARG, QEMU_OPTION_display,
 #endif
 #if defined(CONFIG_GTK)
     "-display gtk[,full-screen=on|off][,gl=on|off][,grab-on-hover=on|off]\n"
-    "            [,show-cursor=on|off][,window-close=on|off]\n"
+    "            [,monitor.<order>=<value>][,show-cursor=on|off][,window-close=on|off]\n"
 #endif
 #if defined(CONFIG_VNC)
     "-display vnc=<display>[,<optargs>]\n"
diff --git a/ui/gtk.c b/ui/gtk.c
index abfcf48547..fcd0e08c16 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -2304,6 +2304,10 @@ static void gtk_display_init(DisplayState *ds, DisplayOptions *opts)
     GtkDisplayState *s = g_malloc0(sizeof(*s));
     GdkDisplay *window_display;
     GtkIconTheme *theme;
+    GtkWidget *win;
+    GdkRectangle dest;
+    uint16List *mon;
+    int n_mon;
     int n_gfx_vcs = 0;
     int i;
     char *dir;
@@ -2384,7 +2388,33 @@ static void gtk_display_init(DisplayState *ds, DisplayOptions *opts)
             n_gfx_vcs++;
         }
     }
-    if (opts->has_full_screen &&
+    if (opts->u.gtk.has_monitor) {
+        i = 0;
+        n_mon = gdk_display_get_n_monitors(window_display);
+        for (mon = opts->u.gtk.monitor; mon; mon = mon->next) {
+            if (mon->value < n_mon) {
+                for (; i < s->nb_vcs; i++) {
+                    win = s->vc[i].window ? s->vc[i].window : s->window;
+                    if (opts->has_full_screen && opts->full_screen) {
+                        gtk_window_fullscreen_on_monitor(
+                            GTK_WINDOW(win),
+                            gdk_display_get_default_screen(window_display),
+                            mon->value);
+                    } else {
+                        gdk_monitor_get_geometry(
+                            gdk_display_get_monitor(window_display, mon->value),
+                            &dest);
+                        gtk_window_move(GTK_WINDOW(win),
+                                        dest.x, dest.y);
+                    }
+                    i++;
+                    break;
+                }
+            }
+        }
+    }
+    if (!opts->u.gtk.has_monitor &&
+        opts->has_full_screen &&
         opts->full_screen) {
         gtk_menu_item_activate(GTK_MENU_ITEM(s->full_screen_item));
     }
-- 
2.30.2