Scale monitor geometries down to device pixels to support multiple monitors in HiDPI

Author: vkareh

mate-panel/panel-multiscreen.c

@@ -88,11 +88,14 @@ panel_multiscreen_get_randr_monitors_for_screen (GdkScreen     *screen,
 						 GdkRectangle **geometries_ret)
 {
 #ifdef HAVE_RANDR
+	GdkDisplay         *display;
+	GdkMonitor         *monitor;
 	Display            *xdisplay;
 	Window              xroot;
 	XRRScreenResources *resources;
 	RROutput            primary;
 	GArray             *geometries;
+	int                 scale;
 	int                 i;
 
 	if (!have_randr)
@@ -138,6 +141,11 @@ panel_multiscreen_get_randr_monitors_for_screen (GdkScreen     *screen,
 		return FALSE;
 
 	primary = XRRGetOutputPrimary (xdisplay, xroot);
+	display = gdk_screen_get_display (screen);
+	monitor = gdk_display_get_primary_monitor (display);
+
+	/* Use scale factor to bring geometries down to device pixels to support HiDPI displays */
+	scale = gdk_monitor_get_scale_factor (monitor);
 
 	geometries = g_array_sized_new (FALSE, FALSE,
 					sizeof (GdkRectangle),
@@ -157,10 +165,10 @@ panel_multiscreen_get_randr_monitors_for_screen (GdkScreen     *screen,
 			crtc = XRRGetCrtcInfo (xdisplay, resources,
 					       output->crtc);
 
-			rect.x	    = crtc->x;
-			rect.y	    = crtc->y;
-			rect.width  = crtc->width;
-			rect.height = crtc->height;
+			rect.x      = crtc->x / scale;
+			rect.y      = crtc->y / scale;
+			rect.width  = crtc->width / scale;
+			rect.height = crtc->height / scale;
 
 			XRRFreeCrtcInfo (crtc);
 
@@ -211,8 +219,21 @@ panel_multiscreen_get_gdk_monitors_for_screen (GdkScreen     *screen,
 	num_monitors = gdk_display_get_n_monitors (display);
 	geometries = g_new (GdkRectangle, num_monitors);
 
-	for (i = 0; i < num_monitors; i++)
-		gdk_monitor_get_geometry (gdk_display_get_monitor (display, i), &(geometries[i]));
+	for (i = 0; i < num_monitors; i++) {
+		GdkMonitor *monitor;
+		int         scale;
+
+		monitor = gdk_display_get_monitor (display, i);
+		scale = gdk_monitor_get_scale_factor (monitor);
+
+		gdk_monitor_get_geometry (monitor, &(geometries[i]));
+
+		/* Scale geometries down to device pixels to support HiDPI displays */
+		geometries[i].x /= scale;
+		geometries[i].y /= scale;
+		geometries[i].width /= scale;
+		geometries[i].height /= scale;
+	}
 
 	*monitors_ret = num_monitors;
 	*geometries_ret = geometries;

mate-panel/panel-run-dialog.c

@@ -1708,7 +1708,6 @@ panel_run_dialog_setup_entry (PanelRunDialog *dialog,
 	GdkScreen             *screen;
 	int                    width_request;
 	GtkWidget             *entry;
-	gint                   scale;
 
 	dialog->combobox = PANEL_GTK_BUILDER_GET (gui, "comboboxentry");
 
@@ -1721,10 +1720,9 @@ panel_run_dialog_setup_entry (PanelRunDialog *dialog,
 		(GTK_COMBO_BOX (dialog->combobox), 0);
 
 	screen = gtk_window_get_screen (GTK_WINDOW (dialog->run_dialog));
-	scale = gtk_widget_get_scale_factor (GTK_WIDGET (dialog->run_dialog));
 
         /* 1/4 the width of the first monitor should be a good value */
-	width_request = panel_multiscreen_width (screen, 0) / (4 * scale);
+	width_request = panel_multiscreen_width (screen, 0) / 4;
 	g_object_set (G_OBJECT (dialog->combobox),
 		      "width_request", width_request,
 		      NULL);

mate-panel/panel-struts.c

@@ -75,10 +75,17 @@ panel_struts_get_monitor_geometry (GdkScreen *screen,
 				   int       *width,
 				   int       *height)
 {
-        *x      = panel_multiscreen_x      (screen, monitor);
-        *y      = panel_multiscreen_y      (screen, monitor);
-        *width  = panel_multiscreen_width  (screen, monitor);
-        *height = panel_multiscreen_height (screen, monitor);
+        GdkDisplay *display;
+        int scale;
+
+        /* Use scale factor to bring strut dimensions up to application pixels to support HiDPI displays */
+        display = gdk_screen_get_display (screen);
+        scale = gdk_monitor_get_scale_factor (gdk_display_get_monitor (display, monitor));
+
+        *x      = panel_multiscreen_x      (screen, monitor) * scale;
+        *y      = panel_multiscreen_y      (screen, monitor) * scale;
+        *width  = panel_multiscreen_width  (screen, monitor) * scale;
+        *height = panel_multiscreen_height (screen, monitor) * scale;
 }
 
 static PanelStrut *

mate-panel/panel-toplevel.c

@@ -290,8 +290,7 @@ static GdkScreen* panel_toplevel_get_screen_geometry(PanelToplevel* toplevel, in
 	 * sorts of awful misalignments and pretend it's all good. Or we can just
 	 * make this thing think that the screen is scaled down, and because GTK+
 	 * already scaled everything up without the panel knowing about it, the whole
-	 * thing somehow works well... sigh.
-	 * @see panel_toplevel_get_monitor_geometry() */
+	 * thing somehow works well... sigh. */
 	*width  = WidthOfScreen (gdk_x11_screen_get_xscreen (screen)) / toplevel->priv->scale;
 	*height = HeightOfScreen (gdk_x11_screen_get_xscreen (screen)) / toplevel->priv->scale;
 
@@ -307,24 +306,17 @@ static GdkScreen* panel_toplevel_get_monitor_geometry(PanelToplevel* toplevel, i
 
 	screen = gtk_window_get_screen(GTK_WINDOW(toplevel));
 
-	if (x) *x = panel_multiscreen_x(screen, toplevel->priv->monitor) / toplevel->priv->scale;
-	if (y) *y = panel_multiscreen_y(screen, toplevel->priv->monitor) / toplevel->priv->scale;
+	if (x) *x = panel_multiscreen_x(screen, toplevel->priv->monitor);
+	if (y) *y = panel_multiscreen_y(screen, toplevel->priv->monitor);
 
-	/* To scale the panels up for HiDPI displays, we can either multiply a lot of
-	 * toplevel geometry attributes by the scale factor, then correct for all
-	 * sorts of awful misalignments and pretend it's all good. Or we can just
-	 * make this thing think that the screen is scaled down, and because GTK+
-	 * already scaled everything up without the panel knowing about it, the whole
-	 * thing somehow works well... sigh.
-	 * @see panel_toplevel_get_screen_geometry() */
 	if (width)
 	{
-		*width  = panel_multiscreen_width(screen, toplevel->priv->monitor) / toplevel->priv->scale;
+		*width  = panel_multiscreen_width(screen, toplevel->priv->monitor);
 	}
 
 	if (height)
 	{
-		*height = panel_multiscreen_height(screen, toplevel->priv->monitor) / toplevel->priv->scale;
+		*height = panel_multiscreen_height(screen, toplevel->priv->monitor);
 	}
 
 	return screen;