[RFC PATCH 3/9] ui/gtk: reset visible flag when window is minimized

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

Add a callback for window-state-event that resets vc->gfx.visible when
associated window is minimized or restored.

In case of virtio-gpu blob scanout, if the window is minimized before
the rendering event for the last guest scanout frame is finished, it cancels
the draw submission and unblocks the pipeline to prevent a permanent lockup.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Daniel P. Berrangé <berrange@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Philippe Mathieu-Daudé <philmd@linaro.org>
Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>
Signed-off-by: Dongwon Kim <dongwon.kim@intel.com>
---
 ui/gtk.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/ui/gtk.c b/ui/gtk.c
index ff4a5c58ea..f9096aea14 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -1419,6 +1419,35 @@ static gboolean gd_tab_window_close(GtkWidget *widget, GdkEvent *event,
     return TRUE;
 }
 
+static gboolean gd_window_state_event(GtkWidget *widget, GdkEvent *event,
+                                      void *opaque)
+{
+    VirtualConsole *vc = opaque;
+
+    if (!vc) {
+        return TRUE;
+    }
+
+    if (event->window_state.new_window_state & GDK_WINDOW_STATE_ICONIFIED) {
+        vc->gfx.visible = false;
+        gd_set_ui_size(vc, 0, 0);
+        if (vc->gfx.guest_fb.dmabuf &&
+            vc->gfx.guest_fb.dmabuf->draw_submitted) {
+            vc->gfx.guest_fb.dmabuf->draw_submitted = false;
+            graphic_hw_gl_block(vc->gfx.dcl.con, false);
+        }
+    } else {
+        GdkWindow *window;
+        window = gtk_widget_get_window(vc->gfx.drawing_area);
+        gd_set_ui_size(vc, gdk_window_get_width(window),
+                       gdk_window_get_height(window));
+
+        vc->gfx.visible = true;
+    }
+
+    return TRUE;
+}
+
 static gboolean gd_win_grab(void *opaque)
 {
     VirtualConsole *vc = opaque;
@@ -1460,6 +1489,9 @@ static void gd_menu_untabify(GtkMenuItem *item, void *opaque)
 
         g_signal_connect(vc->window, "delete-event",
                          G_CALLBACK(gd_tab_window_close), vc);
+        g_signal_connect(vc->window, "window-state-event",
+                         G_CALLBACK(gd_window_state_event), vc);
+
         gtk_widget_show_all(vc->window);
 
         if (qemu_console_is_graphic(vc->gfx.dcl.con)) {
@@ -2498,6 +2530,11 @@ static void gtk_display_init(DisplayState *ds, DisplayOptions *opts)
     }
 
     vc = gd_vc_find_current(s);
+
+    g_signal_connect(s->window, "window-state-event",
+                     G_CALLBACK(gd_window_state_event),
+                     vc);
+
     gtk_widget_set_sensitive(s->view_menu, vc != NULL);
 #ifdef CONFIG_VTE
     gtk_widget_set_sensitive(s->copy_item,
-- 
2.34.1