Add action ToggleShowDesktop

docs/labwc-actions.5.scd

@@ -424,6 +424,13 @@ Actions are used in menus and keyboard/mouse bindings.
 	Toggle the screen magnifier on or off at the last magnification level
 	used.
 
+*<action name="ToggleShowDesktop" />*
+	Minimize all windows in the current workspace so that the desktop becomes
+	visible. On calling the action again the hidden windows are unminimized,
+	provided that - since the initial `ShowDesktop` - (a) no windows have been
+	unminimized; (b) workspaces have not been switched; and (c) no new
+	applications have been started.
+
 *<action name="ZoomIn">*++
 *<action name="ZoomOut">*
 	Increase or decrease the magnification level for the screen magnifier.

include/show-desktop.h

@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef LABWC_SHOW_DESKTOP_H
+#define LABWC_SHOW_DESKTOP_H
+
+void show_desktop_toggle(void);
+void show_desktop_reset(void);
+
+#endif /* LABWC_SHOW_DESKTOP_H */

include/view.h

@@ -184,6 +184,7 @@ struct view {
 	enum ssd_preference ssd_preference;
 	bool shaded;
 	bool minimized;
+	bool was_minimized_by_show_desktop_action;
 	enum view_axis maximized;
 	bool fullscreen;
 	bool tearing_hint;

src/action.c

@@ -28,6 +28,7 @@
 #include "output.h"
 #include "output-virtual.h"
 #include "regions.h"
+#include "show-desktop.h"
 #include "ssd.h"
 #include "theme.h"
 #include "translate.h"
@@ -133,6 +134,7 @@ struct action_arg_list {
 	X(TOGGLE_MAGNIFY, "ToggleMagnify") \
 	X(ZOOM_IN, "ZoomIn") \
 	X(ZOOM_OUT, "ZoomOut") \
+	X(TOGGLE_SHOW_DESKTOP, "ToggleShowDesktop") \
 	X(WARP_CURSOR, "WarpCursor") \
 	X(HIDE_CURSOR, "HideCursor") \
 	X(DEBUG_TOGGLE_KEY_STATE_INDICATOR, "DebugToggleKeyStateIndicator")
@@ -1562,6 +1564,9 @@ run_action(struct view *view, struct action *action,
 	case ACTION_TYPE_ZOOM_OUT:
 		magnifier_set_scale(MAGNIFY_DECREASE);
 		break;
+	case ACTION_TYPE_TOGGLE_SHOW_DESKTOP:
+		show_desktop_toggle();
+		break;
 	case ACTION_TYPE_WARP_CURSOR: {
 		const char *to = action_get_str(action, "to", "output");
 		const char *x = action_get_str(action, "x", "center");

src/desktop.c

@@ -14,6 +14,7 @@
 #include "layers.h"
 #include "node.h"
 #include "output.h"
+#include "show-desktop.h"
 #include "ssd.h"
 #include "view.h"
 #include "workspaces.h"
@@ -113,6 +114,8 @@ desktop_focus_view(struct view *view, bool raise)
 	 */
 	struct view *dialog = view_get_modal_dialog(view);
 	set_or_offer_focus(dialog ? dialog : view);
+
+	show_desktop_reset();
 }
 
 /* TODO: focus layer-shell surfaces also? */

src/meson.build

@@ -22,6 +22,7 @@ labwc_sources = files(
   'seat.c',
   'server.c',
   'session-lock.c',
+  'show-desktop.c',
   'snap-constraints.c',
   'snap.c',
   'tearing.c',

src/show-desktop.c

@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include "show-desktop.h"
+#include <wlr/types/wlr_seat.h>
+#include "common/array.h"
+#include "config/types.h"
+#include "labwc.h"
+#include "view.h"
+
+static bool is_showing_desktop;
+
+static void
+minimize_views(struct wl_array *views, bool minimize)
+{
+	struct view **view;
+	wl_array_for_each_reverse(view, views) {
+		view_minimize(*view, minimize);
+	}
+}
+
+static void
+show(void)
+{
+	static struct wl_array views;
+	wl_array_init(&views);
+
+	/* Build array first as minimize changes server.views */
+	struct view *view;
+	for_each_view(view, &server.views, LAB_VIEW_CRITERIA_CURRENT_WORKSPACE) {
+		if (view->minimized) {
+			continue;
+		}
+		view->was_minimized_by_show_desktop_action = true;
+		array_add(&views, view);
+	}
+	minimize_views(&views, true);
+	is_showing_desktop = true;
+
+	wl_array_release(&views);
+}
+
+static void
+restore(void)
+{
+	static struct wl_array views;
+	wl_array_init(&views);
+
+	struct view *view;
+	for_each_view(view, &server.views, LAB_VIEW_CRITERIA_CURRENT_WORKSPACE) {
+		if (view->was_minimized_by_show_desktop_action) {
+			array_add(&views, view);
+		}
+	}
+	minimize_views(&views, false);
+	show_desktop_reset();
+
+	wl_array_release(&views);
+}
+
+void
+show_desktop_toggle(void)
+{
+	if (is_showing_desktop) {
+		restore();
+	} else {
+		show();
+	}
+}
+
+void
+show_desktop_reset(void)
+{
+	is_showing_desktop = false;
+
+	struct view *view;
+	for_each_view(view, &server.views, LAB_VIEW_CRITERIA_NONE) {
+		view->was_minimized_by_show_desktop_action = false;
+	}
+}

src/workspaces.c

@@ -21,6 +21,7 @@
 #include "input/keyboard.h"
 #include "labwc.h"
 #include "output.h"
+#include "show-desktop.h"
 #include "theme.h"
 #include "view.h"
 
@@ -495,6 +496,8 @@ workspaces_switch_to(struct workspace *target, bool update_focus)
 	desktop_update_top_layer_visibility();
 
 	wlr_ext_workspace_handle_v1_set_active(target->ext_workspace, true);
+
+	show_desktop_reset();
 }
 
 void