src/menu: add support for scalable menu icons

docs/labwc-menu.5.scd

@@ -15,29 +15,37 @@ The menu file must be entirely enclosed within <openbox_menu> and
 </openbox_menu> tags.  Inside these tags, menus are specified as follows:
 
 ```
+<!-- A toplevel menu -->
+<menu id="external_menu_settings" label="External Settings" icon="preferences-other">
+  <item label="Display setting">
+    <action name="Execute" command="wdisplays" />
+  </item>
+</menu>
+
+<!-- Another toplevel menu -->
 <menu id="">
 
   <!-- A menu entry with an action, for example to execute an application -->
-  <item label="">
+  <item label="" icon="">
     <action></action>
   </item>
 
-  <!-- A submenu defined elsewhere -->
+  <!-- A submenu defined elsewhere, uses external label and icon attributes -->
-  <menu id="" />
+  <menu id="external_menu_settings" />
 
   <!-- Horizontal line -->
   <separator />
 
   <!-- An inline submenu -->
-  <menu id="" label="">
+  <menu id="" label="" icon="">
     ...some content...
   </menu>
 
   <!-- Title -->
-  <separator label=""/>
+  <separator label="" />
 
   <!-- Pipemenu -->
-  <menu id="" label="" execute="COMMAND"/>
+  <menu id="" label="" icon="" execute="COMMAND" />
 
 </menu>
 ```
@@ -56,15 +64,28 @@ The menu file must be entirely enclosed within <openbox_menu> and
 		  view to that workspace when selected.
 
 *menu.id* (when nested under other *<menu>* element)
-	Link to a submenu defined elsewhere (by a *<menu id="">* at toplevel)
+	Link to a submenu defined elsewhere (by a *<menu id="">* at toplevel).
 
 *menu.label*
 	The title of the menu, shown in its parent. A label must be given when
 	defining a menu.
 
+*menu.icon*
+	An icon to be rendered, shown in its parent. This argument is optional.
+	See *menu.item.icon* for further details.
+
 *menu.item.label*
 	The visible name of the menu item.
 
+*menu.item.icon*
+	The name of an icon to be rendered in front of the menu entry. This
+	attribute is optional. The name follows naming conventions of "Icon="
+	entries in .desktop files. If used, it is recommended to use the name of
+	the icon only rather than a full path. This ensures that the icon will
+	be looked up in the scale of the output where the menu is rendered. E.g.
+	use of icon="vlc" is suggested over using
+	icon="/usr/share/icons/hicolor/16x16/apps/vlc.png".
+
 *menu.item.action*
 	See labwc-actions(5). Note: XML CDATA is supported for this node in
 	order to maintain compatibility with obmenu-generator.

include/menu/menu.h

@@ -23,6 +23,7 @@ struct menuitem {
 	char *execute;
 	char *id; /* needed for pipemenus */
 	char *text;
+	char *icon_name;
 	const char *arrow;
 	struct menu *parent;
 	struct menu *submenu;
@@ -41,6 +42,7 @@ struct menuitem {
 struct menu {
 	char *id;
 	char *label;
+	char *icon_name;
 	struct menu *parent;
 	struct menu_pipe_context *pipe_ctx;
 
@@ -57,6 +59,7 @@ struct menu {
 	struct wlr_scene_tree *scene_tree;
 	bool is_pipemenu;
 	bool align_left;
+	bool has_icons;
 
 	/* Used to match a window-menu to the view that triggered it. */
 	struct view *triggered_by_view;  /* may be NULL */

src/menu/menu.c

@@ -20,6 +20,7 @@
 #include "common/mem.h"
 #include "common/nodename.h"
 #include "common/scaled-font-buffer.h"
+#include "common/scaled-icon-buffer.h"
 #include "common/scaled-rect-buffer.h"
 #include "common/scene-helpers.h"
 #include "common/spawn.h"
@@ -34,6 +35,8 @@
 #define PIPEMENU_MAX_BUF_SIZE 1048576  /* 1 MiB */
 #define PIPEMENU_TIMEOUT_IN_MS 4000    /* 4 seconds */
 
+#define ICON_SIZE (rc.theme->menu_item_height - 2 * rc.theme->menu_items_padding_y)
+
 /* state-machine variables for processing <item></item> */
 static bool in_item;
 static struct menuitem *current_item;
@@ -163,6 +166,12 @@ item_create_scene_for_state(struct menuitem *item, float *text_color,
 	/* Tree to hold background and label buffers */
 	struct wlr_scene_tree *tree = wlr_scene_tree_create(item->tree);
 
+	int icon_width = 0;
+	int icon_size = ICON_SIZE;
+	if (item->parent->has_icons) {
+		icon_width = theme->menu_items_padding_x + icon_size;
+	}
+
 	/* Create background */
 	int bg_width = menu->size.width
 		- 2 * theme->menu_border_width;
@@ -170,7 +179,16 @@ item_create_scene_for_state(struct menuitem *item, float *text_color,
 
 	int arrow_width = item->arrow ?
 		font_width(&rc.font_menuitem, item->arrow) : 0;
-	int label_max_width = bg_width - 2 * theme->menu_items_padding_x - arrow_width;
+	int label_max_width = bg_width - 2 * theme->menu_items_padding_x - arrow_width - icon_width;
+
+	/* Create icon */
+	if (item->icon_name) {
+		struct scaled_icon_buffer *icon_buffer = scaled_icon_buffer_create(
+			tree, menu->server, icon_size, icon_size);
+		scaled_icon_buffer_set_icon_name(icon_buffer, item->icon_name);
+		wlr_scene_node_set_position(&icon_buffer->scene_buffer->node,
+			theme->menu_items_padding_x, theme->menu_items_padding_y);
+	}
 
 	/* Create label */
 	struct scaled_font_buffer *label_buffer = scaled_font_buffer_create(tree);
@@ -178,7 +196,7 @@ item_create_scene_for_state(struct menuitem *item, float *text_color,
 	scaled_font_buffer_update(label_buffer, item->text, label_max_width,
 		&rc.font_menuitem, text_color, bg_color);
 	/* Vertically center and left-align label */
-	int x = theme->menu_items_padding_x;
+	int x = theme->menu_items_padding_x + icon_width;
 	int y = (theme->menu_item_height - label_buffer->height) / 2;
 	wlr_scene_node_set_position(&label_buffer->scene_buffer->node, x, y);
 
@@ -363,6 +381,10 @@ menu_update_scene(struct menu *menu)
 			+ 2 * theme->menu_border_width;
 		menu->size.width = MAX(menu->size.width, width);
 	}
+
+	if (menu->has_icons) {
+		menu->size.width += theme->menu_items_padding_x + ICON_SIZE;
+	}
 	menu->size.width = MAX(menu->size.width, theme->menu_min_width);
 	menu->size.width = MIN(menu->size.width, theme->menu_max_width);
 
@@ -436,10 +458,13 @@ fill_item(char *nodename, char *content)
 		wlr_log(WLR_ERROR, "expect <item label=\"\"> element first. "
 			"nodename: '%s' content: '%s'", nodename, content);
 	} else if (!strcmp(nodename, "icon")) {
-		/*
+#if HAVE_LIBSFDO
-		 * Do nothing as we don't support menu icons - just avoid
+		// TODO: add some rc.menu_icons bool
-		 * logging errors if a menu.xml file contains icon="" entries.
+		if (true && !string_null_or_empty(content)) {
-		 */
+			xstrdup_replace(current_item->icon_name, content);
+			current_menu->has_icons = true;
+		}
+#endif
 	} else if (!strcmp(nodename, "name.action")) {
 		current_item_action = action_create(content);
 		if (current_item_action) {
@@ -468,6 +493,7 @@ item_destroy(struct menuitem *item)
 	free(item->execute);
 	free(item->id);
 	free(item->text);
+	free(item->icon_name);
 	free(item);
 }
 
@@ -647,6 +673,7 @@ static void
 handle_menu_element(xmlNode *n, struct server *server)
 {
 	char *label = (char *)xmlGetProp(n, (const xmlChar *)"label");
+	char *icon_name = (char *)xmlGetProp(n, (const xmlChar *)"icon");
 	char *execute = (char *)xmlGetProp(n, (const xmlChar *)"execute");
 	char *id = (char *)xmlGetProp(n, (const xmlChar *)"id");
 
@@ -666,6 +693,7 @@ handle_menu_element(xmlNode *n, struct server *server)
 		} else {
 			current_item = item_create(current_menu, label,
 				/* arrow */ true);
+			fill_item("icon", icon_name);
 			current_item_action = NULL;
 			current_item->execute = xstrdup(execute);
 			current_item->id = xstrdup(id);
@@ -695,6 +723,7 @@ handle_menu_element(xmlNode *n, struct server *server)
 			 */
 			current_item = item_create(current_menu, label, true);
 			if (current_item) {
+				fill_item("icon", icon_name);
 				submenu = &current_item->submenu;
 			} else {
 				submenu = NULL;
@@ -702,6 +731,9 @@ handle_menu_element(xmlNode *n, struct server *server)
 		}
 		++menu_level;
 		current_menu = menu_create(server, id, label);
+		if (icon_name) {
+			current_menu->icon_name = xstrdup(icon_name);
+		}
 		if (submenu) {
 			*submenu = current_menu;
 		}
@@ -739,6 +771,7 @@ handle_menu_element(xmlNode *n, struct server *server)
 		if (menu) {
 			current_item = item_create(current_menu, menu->label, true);
 			if (current_item) {
+				fill_item("icon", menu->icon_name);
 				current_item->submenu = menu;
 			}
 		} else {
@@ -747,6 +780,7 @@ handle_menu_element(xmlNode *n, struct server *server)
 	}
 error:
 	free(label);
+	free(icon_name);
 	free(execute);
 	free(id);
 }
@@ -1209,6 +1243,7 @@ menu_free(struct menu *menu)
 	wl_list_remove(&menu->link);
 	zfree(menu->id);
 	zfree(menu->label);
+	zfree(menu->icon_name);
 	zfree(menu);
 }