Merge branch 'hide_empty_taskbars' into 'master'

Add behavior to hide an empty taskbar in multi_desktop mode

- [x] Hide empty taskbar
- [x] Handle case when workspace name is not showing
- [x] Make it configurable
- [x] Fix bugs
    - [x] Size issue when removing taskbars
    - [x] Overlapping taskbars (?)

See merge request !17

src/config.c

@@ -771,6 +771,8 @@ void add_entry(char *key, char *value)
 		hide_inactive_tasks = atoi(value);
 	} else if (strcmp(key, "taskbar_hide_different_monitor") == 0) {
 		hide_task_diff_monitor = atoi(value);
+	} else if (strcmp(key, "taskbar_hide_if_empty") == 0) {
+		hide_taskbar_if_empty = atoi(value);
 	} else if (strcmp(key, "taskbar_always_show_all_desktop_tasks") == 0) {
 		always_show_all_desktop_tasks = atoi(value);
 	} else if (strcmp(key, "taskbar_sort_order") == 0) {

src/panel.c

@@ -269,12 +269,11 @@ void init_panel()
 
 		if (panel_autohide)
 			autohide_trigger_hide(p);
-
-		update_taskbar_visibility(p);
 	}
 
 	taskbar_refresh_tasklist();
 	reset_active_task();
+	update_all_taskbars_visibility();
 }
 
 void init_panel_size_and_position(Panel *panel)
@@ -395,7 +394,11 @@ gboolean resize_panel(void *obj)
 		int total_size = 0;
 		int total_name_size = 0;
 		int total_items = 0;
+		int visible_taskbars = 0;
 		for (int i = 0; i < panel->num_desktops; i++) {
+			if (!panel->taskbar[i].area.on_screen)
+				continue;
+			visible_taskbars++;
 			if (panel_horizontal) {
 				total_size += panel->taskbar[i].area.width;
 			} else {
@@ -427,14 +430,16 @@ gboolean resize_panel(void *obj)
 		if (total_items) {
 			int actual_name_size;
 			if (total_name_size <= total_size) {
-				actual_name_size = total_name_size / panel->num_desktops;
+				actual_name_size = total_name_size / visible_taskbars;
 			} else {
-				actual_name_size = total_size / panel->num_desktops;
+				actual_name_size = total_size / visible_taskbars;
 			}
 			total_size -= total_name_size;
 
 			for (int i = 0; i < panel->num_desktops; i++) {
 				Taskbar *taskbar = &panel->taskbar[i];
+				if (!taskbar->area.on_screen)
+					continue;
 
 				int requested_size = (panel_horizontal ? left_right_border_width(&taskbar->area)
 				                                       : top_bottom_border_width(&taskbar->area)) +

src/taskbar/taskbar.c

@@ -41,6 +41,7 @@ gboolean taskbar_enabled;
 gboolean taskbar_distribute_size;
 gboolean hide_inactive_tasks;
 gboolean hide_task_diff_monitor;
+gboolean hide_taskbar_if_empty;
 gboolean always_show_all_desktop_tasks;
 TaskbarSortMethod taskbar_sort_method;
 Alignment taskbar_alignment;
@@ -74,6 +75,7 @@ void default_taskbar()
 	taskbar_distribute_size = FALSE;
 	hide_inactive_tasks = FALSE;
 	hide_task_diff_monitor = FALSE;
+	hide_taskbar_if_empty = FALSE;
 	always_show_all_desktop_tasks = FALSE;
 	taskbar_sort_method = TASKBAR_NOSORT;
 	taskbar_alignment = ALIGN_LEFT;
@@ -169,7 +171,7 @@ void init_taskbar_panel(void *p)
 	if (panel_horizontal) {
 		panel->g_taskbar.area.posy = top_border_width(&panel->area) + panel->area.paddingy;
 		panel->g_taskbar.area.height =
-			panel->area.height - top_bottom_border_width(&panel->area) - 2 * panel->area.paddingy;
+		    panel->area.height - top_bottom_border_width(&panel->area) - 2 * panel->area.paddingy;
 		panel->g_taskbar.area_name.posy = panel->g_taskbar.area.posy;
 		panel->g_taskbar.area_name.height = panel->g_taskbar.area.height;
 	} else {
@@ -430,18 +432,52 @@ gboolean resize_taskbar(void *obj)
 	return FALSE;
 }
 
+gboolean taskbar_is_not_empty(Taskbar *taskbar)
+{
+	GList *l = taskbar->area.children;
+	if (taskbarname_enabled)
+		l = l->next;
+	for (; l != NULL; l = l->next) {
+		if (((Task *)l->data)->area.on_screen) {
+			return TRUE;
+		}
+	}
+	return FALSE;
+}
+
+void update_one_taskbar_visibility(Taskbar *taskbar)
+{
+	if (taskbar->desktop == server.desktop) {
+		// Taskbar for current desktop is always shown
+		show(&taskbar->area);
+	}
+	else if (taskbar_mode == MULTI_DESKTOP && (taskbar_is_not_empty(taskbar) || hide_taskbar_if_empty == FALSE)) {
+		// MULTI_DESKTOP : show non-empty taskbars
+		show(&taskbar->area);
+	} else {
+		hide(&taskbar->area);
+	}
+}
+
+void update_all_taskbars_visibility()
+{
+	for (int i = 0; i < num_panels; i++) {
+		Panel *panel = &panels[i];
+		for (int j = 0; j < panel->num_desktops; j++) {
+			update_one_taskbar_visibility(&panel->taskbar[j]);
+		}
+	}
+}
+
 void set_taskbar_state(Taskbar *taskbar, TaskbarState state)
 {
 	taskbar->area.bg = panels[0].g_taskbar.background[state];
 	if (taskbarname_enabled) {
 		taskbar->bar_name.area.bg = panels[0].g_taskbar.background_name[state];
 	}
-	if (taskbar_mode != MULTI_DESKTOP) {
-		if (state == TASKBAR_NORMAL)
-			taskbar->area.on_screen = FALSE;
-		else
-			taskbar->area.on_screen = TRUE;
-	}
+
+	update_one_taskbar_visibility(taskbar);
+
 	if (taskbar->area.on_screen) {
 		schedule_redraw(&taskbar->area);
 		if (taskbarname_enabled) {
@@ -459,22 +495,6 @@ void set_taskbar_state(Taskbar *taskbar, TaskbarState state)
 	panel_refresh = TRUE;
 }
 
-void update_taskbar_visibility(void *p)
-{
-	Panel *panel = (Panel *)p;
-
-	for (int j = 0; j < panel->num_desktops; j++) {
-		Taskbar *taskbar = &panel->taskbar[j];
-		if (taskbar_mode != MULTI_DESKTOP && taskbar->desktop != server.desktop) {
-			// SINGLE_DESKTOP and not current desktop
-			taskbar->area.on_screen = FALSE;
-		} else {
-			taskbar->area.on_screen = TRUE;
-		}
-	}
-	panel_refresh = TRUE;
-}
-
 #define NONTRIVIAL 2
 gint compare_tasks_trivial(Task *a, Task *b, Taskbar *taskbar)
 {

src/taskbar/taskbar.h

@@ -49,6 +49,7 @@ extern gboolean taskbar_enabled;
 extern gboolean taskbar_distribute_size;
 extern gboolean hide_inactive_tasks;
 extern gboolean hide_task_diff_monitor;
+extern gboolean hide_taskbar_if_empty;
 extern gboolean always_show_all_desktop_tasks;
 extern TaskbarSortMethod taskbar_sort_method;
 extern Alignment taskbar_alignment;
@@ -79,10 +80,11 @@ Task *get_task(Window win);
 // However for windows shown on all desktops, there are multiple buttons, one for each taskbar.
 GPtrArray *get_task_buttons(Window win);
 
+// Change state of a taskbar (ACTIVE or NORMAL)
 void set_taskbar_state(Taskbar *taskbar, TaskbarState state);
 
-// Updates the visibility of each taskbar when the current desktop changes.
-void update_taskbar_visibility(void *p);
+// Updates the visibility of all taskbars
+void update_all_taskbars_visibility();
 
 // Sorts the taskbar(s) on which the window is present.
 void sort_taskbar_for_win(Window win);

src/tint.c

@@ -1010,7 +1010,7 @@ void event_property_notify(XEvent *e)
 			int old_desktop = server.desktop;
 			server_get_number_of_desktops();
 			server.desktop = get_current_desktop();
-			if (old_num_desktops != server.num_desktops) {
+			if (old_num_desktops != server.num_desktops) { // If number of desktop changed
 				if (server.num_desktops <= server.desktop) {
 					server.desktop = server.num_desktops - 1;
 				}
@@ -1019,11 +1019,11 @@ void event_property_notify(XEvent *e)
 				for (int i = 0; i < num_panels; i++) {
 					init_taskbar_panel(&panels[i]);
 					set_panel_items_order(&panels[i]);
-					update_taskbar_visibility(&panels[i]);
 					panels[i].area.resize_needed = 1;
 				}
 				taskbar_refresh_tasklist();
 				reset_active_task();
+				update_all_taskbars_visibility();
 				panel_refresh = TRUE;
 			} else if (old_desktop != server.desktop) {
 				for (int i = 0; i < num_panels; i++) {
@@ -1092,6 +1092,7 @@ void event_property_notify(XEvent *e)
 			if (debug)
 				fprintf(stderr, "%s %d: win = root, atom = _NET_CLIENT_LIST\n", __FUNCTION__, __LINE__);
 			taskbar_refresh_tasklist();
+			update_all_taskbars_visibility();
 			panel_refresh = TRUE;
 		}
 		// Change active