Add FocusOutput action

Fixes #806

Suggested-by: @EysseW
Tested-by: @EysseW

docs/labwc-actions.5.scd

@@ -80,6 +80,11 @@ Actions are used in menus and keyboard/mouse bindings.
 	to Virtual Machines, VNC clients or nested compositors.
 	A second call will restore all original keybinds.
 
+*<action name="FocusOutput" output="HDMI-A-1" />*
+	Give focus to topmost window on given output and warp the cursor
+	to the center of the window. If the given output does not contain
+	any windows, the cursor is centered on the given output.
+
 *<action name="GoToDesktop" to="value" />*
 	Switch to workspace. Supported values are "last", "left", "right" or the
 	full name of a workspace or its index (starting at 1) as configured in

include/labwc.h

@@ -372,6 +372,7 @@ void desktop_move_to_front(struct view *view);
 void desktop_move_to_back(struct view *view);
 void desktop_focus_and_activate_view(struct seat *seat, struct view *view);
 void desktop_arrange_all_views(struct server *server);
+void desktop_focus_output(struct output *output);
 
 enum lab_cycle_dir {
 	LAB_CYCLE_DIR_NONE,
@@ -418,6 +419,7 @@ void output_init(struct server *server);
 void output_manager_init(struct server *server);
 struct output *output_from_wlr_output(struct server *server,
 	struct wlr_output *wlr_output);
+struct output *output_from_name(struct server *server, const char *name);
 struct output *output_nearest_to(struct server *server, int lx, int ly);
 struct output *output_nearest_to_cursor(struct server *server);
 bool output_is_usable(struct output *output);

src/action.c

@@ -61,6 +61,7 @@ enum action_type {
 	ACTION_TYPE_SEND_TO_DESKTOP,
 	ACTION_TYPE_SNAP_TO_REGION,
 	ACTION_TYPE_TOGGLE_KEYBINDS,
+	ACTION_TYPE_FOCUS_OUTPUT,
 };
 
 const char *action_names[] = {
@@ -90,6 +91,7 @@ const char *action_names[] = {
 	"SendToDesktop",
 	"SnapToRegion",
 	"ToggleKeybinds",
+	"FocusOutput",
 	NULL
 };
 
@@ -119,6 +121,9 @@ action_arg_from_xml_node(struct action *action, char *nodename, char *content)
 	} else if (!strcmp(nodename, "region.action")) {
 		/* SnapToRegion */
 		action_arg_add_str(action, NULL, content);
+	} else if (!strcmp(nodename, "output.action")) {
+		/* FocusOutput */
+		action_arg_add_str(action, NULL, content);
 	}
 }
 
@@ -470,6 +475,14 @@ actions_run(struct view *activator, struct server *server,
 			wlr_log(WLR_DEBUG, "%s keybinds",
 				server->seat.inhibit_keybinds ? "Disabled" : "Enabled");
 			break;
+		case ACTION_TYPE_FOCUS_OUTPUT:
+			if (!arg) {
+				wlr_log(WLR_ERROR, "Missing argument for FocusOutput");
+				break;
+			}
+			const char *output_name = action_str_from_arg(arg);
+			desktop_focus_output(output_from_name(server, output_name));
+			break;
 		case ACTION_TYPE_INVALID:
 			wlr_log(WLR_ERROR, "Not executing unknown action");
 			break;

src/desktop.c

@@ -268,6 +268,46 @@ desktop_focus_topmost_mapped_view(struct server *server)
 	desktop_move_to_front(view);
 }
 
+void
+desktop_focus_output(struct output *output)
+{
+	if (!output_is_usable(output) || output->server->input_mode
+			!= LAB_INPUT_STATE_PASSTHROUGH) {
+		return;
+	}
+	struct view *view;
+	struct wlr_scene_node *node;
+	struct wlr_output_layout *layout = output->server->output_layout;
+	struct wl_list *list_head =
+		&output->server->workspace_current->tree->children;
+	wl_list_for_each_reverse(node, list_head, link) {
+		if (!node->data) {
+			continue;
+		}
+		view = node_view_from_node(node);
+		if (!isfocusable(view)) {
+			continue;
+		}
+		if (wlr_output_layout_intersects(layout,
+				output->wlr_output, &view->current)) {
+			desktop_focus_and_activate_view(&output->server->seat, view);
+			wlr_cursor_warp(output->server->seat.cursor, NULL,
+				view->current.x + view->current.width / 2,
+				view->current.y + view->current.height / 2);
+			cursor_update_focus(output->server);
+			return;
+		}
+	}
+	/* No view found on desired output */
+	struct wlr_box layout_box;
+	wlr_output_layout_get_box(output->server->output_layout,
+		output->wlr_output, &layout_box);
+	wlr_cursor_warp(output->server->seat.cursor, NULL,
+		layout_box.x + output->usable_area.x + output->usable_area.width / 2,
+		layout_box.y + output->usable_area.y + output->usable_area.height / 2);
+	cursor_update_focus(output->server);
+}
+
 static struct wlr_surface *
 get_surface_from_layer_node(struct wlr_scene_node *node)
 {

src/output.c

@@ -8,6 +8,7 @@
 
 #define _POSIX_C_SOURCE 200809L
 #include <assert.h>
+#include <strings.h>
 #include <wlr/types/wlr_buffer.h>
 #include <wlr/types/wlr_drm_lease_v1.h>
 #include <wlr/types/wlr_output.h>
@@ -458,6 +459,21 @@ output_from_wlr_output(struct server *server, struct wlr_output *wlr_output)
 	return NULL;
 }
 
+struct output *
+output_from_name(struct server *server, const char *name)
+{
+	struct output *output;
+	wl_list_for_each(output, &server->outputs, link) {
+		if (!output_is_usable(output) || !output->wlr_output->name) {
+			continue;
+		}
+		if (!strcasecmp(name, output->wlr_output->name)) {
+			return output;
+		}
+	}
+	return NULL;
+}
+
 struct output *
 output_nearest_to(struct server *server, int lx, int ly)
 {