ssd: allow hiding titlebar on maximization

<core disableMaximizedServerDecor="yes"> hides the titlebar when a window
is maximized.

Co-authored-by: @CosmicFusion

docs/labwc-config.5.scd

@@ -171,6 +171,7 @@ this is for compatibility with Openbox.
 ```
 <core>
   <decoration>server</decoration>
+  <maximizedDecoration>titlebar</maximizedDecoration>
   <gap>0</gap>
   <adaptiveSync>no</adaptiveSync>
   <allowTearing>no</allowTearing>
@@ -186,6 +187,11 @@ this is for compatibility with Openbox.
 	that it is not always possible to turn off client side decorations.
 	Default is server.
 
+*<core><maximizedDecoration>* [titlebar|none]
+	Specify how server side decorations are shown for maximized windows.
+	*titlebar* shows titlebar above a maximized window. *none* shows no server
+	side decorations around a maximized window. Default is titlebar.
+
 *<core><gap>*
 	The distance in pixels between windows and output edges when using
 	movement actions, for example MoveToEdge. Default is 0.

docs/rc.xml.all

@@ -11,6 +11,7 @@
 
   <core>
     <decoration>server</decoration>
+    <maximizedDecoration>titlebar</maximizedDecoration>
     <gap>0</gap>
     <adaptiveSync>no</adaptiveSync>
     <allowTearing>no</allowTearing>

include/config/rcxml.h

@@ -66,6 +66,7 @@ struct rcxml {
 
 	/* core */
 	bool xdg_shell_server_side_deco;
+	bool hide_maximized_window_titlebar;
 	int gap;
 	enum adaptive_sync_mode adaptive_sync;
 	enum tearing_mode allow_tearing;

src/config/rcxml.c

@@ -1094,6 +1094,12 @@ entry(xmlNode *node, char *nodename, char *content)
 		} else {
 			rc.xdg_shell_server_side_deco = true;
 		}
+	} else if (!strcasecmp(nodename, "maximizedDecoration.core")) {
+		if (!strcasecmp(content, "titlebar")) {
+			rc.hide_maximized_window_titlebar = false;
+		} else if (!strcasecmp(content, "none")) {
+			rc.hide_maximized_window_titlebar = true;
+		}
 	} else if (!strcmp(nodename, "gap.core")) {
 		rc.gap = atoi(content);
 	} else if (!strcasecmp(nodename, "adaptiveSync.core")) {
@@ -1370,6 +1376,7 @@ rcxml_init(void)
 	rc.placement_cascade_offset_y = 0;
 
 	rc.xdg_shell_server_side_deco = true;
+	rc.hide_maximized_window_titlebar = false;
 	rc.show_title = true;
 	rc.title_layout_loaded = false;
 	rc.ssd_keep_border = true;

src/ssd/ssd.c

@@ -312,6 +312,12 @@ ssd_update_geometry(struct ssd *ssd)
 		|| ssd->state.was_squared != squared
 		|| ssd->state.was_omnipresent != view->visible_on_all_workspaces;
 
+	/*
+	 * (Un)maximization updates titlebar visibility with
+	 * maximizedDecoration=none
+	 */
+	ssd_set_titlebar(ssd, view_titlebar_visible(view));
+
 	if (update_extents) {
 		ssd_extents_update(ssd);
 	}

src/view.c

@@ -1660,6 +1660,10 @@ undecorate(struct view *view)
 bool
 view_titlebar_visible(struct view *view)
 {
+	if (view->maximized == VIEW_AXIS_BOTH
+			&& rc.hide_maximized_window_titlebar) {
+		return false;
+	}
 	return view->ssd_mode == LAB_SSD_MODE_FULL;
 }