ui/gtk: Add keep-aspect-ratio option

When aspect ratio of host window and that of guest display are not
aligned, we can either zoom the guest content to fill the whole host
window or add padding to respect aspect ratio of the guest. Add an
option keep-aspect-ratio to allow users to select their preferred
behavior in this case.

Suggested-by: BALATON Zoltan <balaton@eik.bme.hu>
Suggested-by: Kim, Dongwon <dongwon.kim@intel.com>
Signed-off-by: Weifeng Liu <weifeng.liu.z@gmail.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20250601045245.36778-2-weifeng.liu.z@gmail.com>

diff --git a/include/ui/gtk.h b/include/ui/gtk.h
index d3944046dbb1ba7ac87819fce0512678f271f5ec..b7cfbf218e83dba7b6eebda892e0def8f726d96a 100644 (file)
--- a/include/ui/gtk.h
+++ b/include/ui/gtk.h
@@ -140,6 +140,7 @@ struct GtkDisplayState {
     GdkCursor *null_cursor;
     Notifier mouse_mode_notifier;
     gboolean free_scale;
+    gboolean keep_aspect_ratio;
 
     bool external_pause_update;
 

diff --git a/qapi/ui.json b/qapi/ui.json
index 514fa159b1058cfe5e7e095894b4740e9cc088dc..9e496b4835e788f0c08f7f278b50a3ea11d0a83e 100644 (file)
--- a/qapi/ui.json
+++ b/qapi/ui.json
@@ -1335,13 +1335,17 @@
 # @show-menubar: Display the main window menubar.  Defaults to "on".
 #     (Since 8.0)
 #
+# @keep-aspect-ratio: Keep width/height aspect ratio of guest content when
+#     resizing host window.  Defaults to "on". (Since 10.1)
+#
 # Since: 2.12
 ##
 { 'struct'  : 'DisplayGTK',
-  'data'    : { '*grab-on-hover' : 'bool',
-                '*zoom-to-fit'   : 'bool',
-                '*show-tabs'     : 'bool',
-                '*show-menubar'  : 'bool'  } }
+  'data'    : { '*grab-on-hover'     : 'bool',
+                '*zoom-to-fit'       : 'bool',
+                '*show-tabs'         : 'bool',
+                '*show-menubar'      : 'bool',
+                '*keep-aspect-ratio' : 'bool'  } }
 
 ##
 # @DisplayEGLHeadless:

diff --git a/ui/gtk.c b/ui/gtk.c
index 8c4a94c8f6b390078d2f57f6a960a78fa38c9ff1..9104509ee151c6177d329dea20fc7fca45778867 100644 (file)
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -828,8 +828,12 @@ void gd_update_scale(VirtualConsole *vc, int ww, int wh, int fbw, int fbh)
 
         sx = (double)ww / fbw;
         sy = (double)wh / fbh;
-
-        vc->gfx.scale_x = vc->gfx.scale_y = MIN(sx, sy);
+        if (vc->s->keep_aspect_ratio) {
+            vc->gfx.scale_x = vc->gfx.scale_y = MIN(sx, sy);
+        } else {
+            vc->gfx.scale_x = sx;
+            vc->gfx.scale_y = sy;
+        }
     }
 }
 /**
@@ -2328,6 +2332,10 @@ static GSList *gd_vc_gfx_init(GtkDisplayState *s, VirtualConsole *vc,
         s->free_scale = true;
     }
 
+    s->keep_aspect_ratio = true;
+    if (s->opts->u.gtk.has_keep_aspect_ratio)
+        s->keep_aspect_ratio = s->opts->u.gtk.keep_aspect_ratio;
+
     for (i = 0; i < INPUT_EVENT_SLOTS_MAX; i++) {
         struct touch_slot *slot = &touch_slots[i];
         slot->tracking_id = -1;