Add ability to reorder workspaces (#464)

Author: donadigo

src/DragDropAction.vala

@@ -19,15 +19,17 @@ using Clutter;
 
 namespace Gala
 {
+	[Flags]
 	public enum DragDropActionType
 	{
-		SOURCE = 0,
+		SOURCE,
 		DESTINATION
 	}
 
 	public class DragDropAction : Clutter.Action
 	{
 		static Gee.HashMap<string,Gee.LinkedList<Actor>>? sources = null;
+		static Gee.HashMap<string,Gee.LinkedList<Actor>>? destinations = null;
 
 		/**
 		 * A drag has been started. You have to connect to this signal and
@@ -55,9 +57,10 @@ namespace Gala
 		/**
 		 * The destination has been crossed
 		 *
+		 * @param target the target actor that is crossing the destination
 		 * @param hovered indicates whether the actor is now hovered or not
 		 */
-		public signal void crossed (bool hovered);
+		public signal void crossed (Actor? target, bool hovered);
 
 		/**
 		 * Emitted on the source when a destination is crossed.
@@ -97,7 +100,8 @@ namespace Gala
 		 */
 		public bool allow_bubbling { get; set; default = true; }
 
-		Actor? hovered = null;
+		public Actor? hovered { private get; set; default = null; }
+		
 		bool clicked = false;
 		float last_x;
 		float last_y;
@@ -116,6 +120,10 @@ namespace Gala
 
 			if (sources == null)
 				sources = new Gee.HashMap<string,Gee.LinkedList<Actor>> ();
+
+			if (destinations == null)
+				destinations = new Gee.HashMap<string,Gee.LinkedList<Actor>> ();
+
 		}
 
 		~DragDropAction ()
@@ -139,17 +147,22 @@ namespace Gala
 
 		void release_actor (Actor actor)
 		{
-			if (drag_type == DragDropActionType.SOURCE) {
+			if (DragDropActionType.SOURCE in drag_type) {
 				actor.button_press_event.disconnect (source_clicked);
 
 				var source_list = sources.@get (drag_id);
 				source_list.remove (actor);
+			} 
+			
+			if (DragDropActionType.DESTINATION in drag_type) {
+				var dest_list = destinations[drag_id];
+				dest_list.remove (actor);
 			}
 		}
 
 		void connect_actor (Actor actor)
 		{
-			if (drag_type == DragDropActionType.SOURCE) {
+			if (DragDropActionType.SOURCE in drag_type) {
 				actor.button_press_event.connect (source_clicked);
 
 				var source_list = sources.@get (drag_id);
@@ -160,12 +173,22 @@ namespace Gala
 
 				source_list.add (actor);
 			}
+
+			if (DragDropActionType.DESTINATION in drag_type) {
+				var dest_list = destinations[drag_id];
+				if (dest_list == null) {
+					dest_list = new Gee.LinkedList<Actor> ();
+					destinations[drag_id] = dest_list;
+				}
+
+				dest_list.add (actor);
+			}
 		}
 
-		void emit_crossed (Actor destination, bool hovered)
+		void emit_crossed (Actor destination, bool is_hovered)
 		{
-			get_drag_drop_action (destination).crossed (hovered);
-			destination_crossed (destination, hovered);
+			get_drag_drop_action (destination).crossed (actor, is_hovered);
+			destination_crossed (destination, is_hovered);
 		}
 
 		bool source_clicked (ButtonEvent event)
@@ -208,7 +231,13 @@ namespace Gala
 
 							var source_list = sources.@get (drag_id);
 							if (source_list != null) {
+								var dest_list = destinations[drag_id];
 								foreach (var actor in source_list) {
+									// Do not unset reactivity on destinations
+									if (actor in dest_list) {
+										continue;
+									}
+
 									actor.reactive = false;
 								}
 							}
@@ -310,7 +339,7 @@ namespace Gala
 			foreach (var action in actor.get_actions ()) {
 				drop_action = action as DragDropAction;
 				if (drop_action == null
-					|| drop_action.drag_type != DragDropActionType.DESTINATION
+					|| !(DragDropActionType.DESTINATION in drop_action.drag_type)
 					|| drop_action.drag_id != drag_id)
 					continue;
 

src/Widgets/IconGroup.vala

@@ -81,8 +81,11 @@ namespace Gala
 			}
 		}
 
+		DragDropAction drag_action;
+
 		public Workspace workspace { get; construct; }
 
+		Actor? prev_parent = null;
 		Actor close_button;
 		Actor icon_container;
 		Cogl.Material dummy_material;
@@ -110,15 +113,13 @@ namespace Gala
 
 			dummy_material = new Cogl.Material ();
 
-			var click = new ClickAction ();
-			click.clicked.connect (() => selected ());
-			// when the actor is pressed, the ClickAction grabs all events, so we won't be
-			// notified when the cursor leaves the actor, which makes our close button stay
-			// forever. To fix this we hide the button for as long as the actor is pressed.
-			click.notify["pressed"].connect (() => {
-				toggle_close_button (!click.pressed && get_has_pointer ());
-			});
-			add_action (click);
+			drag_action = new DragDropAction (DragDropActionType.SOURCE | DragDropActionType.DESTINATION, "multitaskingview-window");
+			drag_action.actor_clicked.connect (() => selected ());
+			drag_action.drag_begin.connect (drag_begin);
+			drag_action.drag_end.connect (drag_end);
+			drag_action.drag_canceled.connect (drag_canceled);
+			drag_action.notify["dragging"].connect (redraw);
+			add_action (drag_action);
 
 			icon_container = new Actor ();
 			icon_container.width = width;
@@ -213,7 +214,7 @@ namespace Gala
 		 */
 		public override void paint ()
 		{
-			if (backdrop_opacity < 1) {
+			if (backdrop_opacity < 1 || drag_action.dragging) {
 				base.paint ();
 				return;
 			}
@@ -309,6 +310,14 @@ namespace Gala
 			}
 		}
 
+		/**
+		 * Sets a hovered actor for the drag action.
+		 */
+		public void set_hovered_actor (Actor actor)
+		{
+			drag_action.hovered = actor;
+		}
+
 		/**
 		 * Trigger a redraw
 		 */
@@ -365,7 +374,13 @@ namespace Gala
 				5 * scale
 			);
 
-			cr.set_source_rgba (0, 0, 0, 0.1);
+			if (drag_action.dragging) {
+				const double BG_COLOR = 53.0 / 255.0;
+				cr.set_source_rgba (BG_COLOR, BG_COLOR, BG_COLOR, 0.7);
+			} else {
+				cr.set_source_rgba (0, 0, 0, 0.1);
+			}
+
 			cr.fill_preserve ();
 
 			cr.set_line_width (1 * scale);
@@ -489,5 +504,69 @@ namespace Gala
 
 			return false;
 		}
+
+		Actor drag_begin (float click_x, float click_y)
+		{
+			unowned Screen screen = workspace.get_screen ();
+			if (icon_container.get_n_children () < 1 &&
+				Prefs.get_dynamic_workspaces () &&
+				workspace.index () == screen.get_n_workspaces () - 1) {
+				return null;
+			}
+
+			float abs_x, abs_y;
+			float prev_parent_x, prev_parent_y;
+
+			prev_parent = get_parent ();
+			prev_parent.get_transformed_position (out prev_parent_x, out prev_parent_y);
+
+			var stage = get_stage ();
+			var container = prev_parent as IconGroupContainer;
+			if (container != null) {
+				container.remove_group_in_place (this);
+				container.reset_thumbs (0);
+			} else {
+				prev_parent.remove_child (this);
+			}
+
+			stage.add_child (this);
+
+			get_transformed_position (out abs_x, out abs_y);
+			set_position (abs_x + prev_parent_x, abs_y + prev_parent_y);
+
+			close_button.opacity = 0;
+
+			return this;
+		}
+
+		void drag_end (Actor destination)
+		{
+			if (destination is WorkspaceInsertThumb) {
+				get_parent ().remove_child (this);
+	
+				unowned WorkspaceInsertThumb inserter = (WorkspaceInsertThumb) destination;
+				workspace.get_screen ().reorder_workspace (workspace, inserter.workspace_index);
+
+				restore_group ();
+			} else {
+				drag_canceled ();
+			}
+		}
+
+		void drag_canceled ()
+		{
+			get_parent ().remove_child (this);
+			restore_group ();
+		}
+
+		void restore_group ()
+		{
+			var container = prev_parent as IconGroupContainer;
+			if (container != null) {
+				container.add_group (this);
+				container.request_reposition (false);
+				container.reset_thumbs (WorkspaceInsertThumb.EXPAND_DELAY);
+			}
+		}
 	}
 }

src/Widgets/IconGroupContainer.vala

@@ -30,7 +30,7 @@ namespace Gala
 		public const int SPACING = 48;
 		public const int GROUP_WIDTH = 64;
 
-		public signal void request_reposition ();
+		public signal void request_reposition (bool animate);
 
 		public Screen screen { get; construct; }
 
@@ -65,9 +65,50 @@ namespace Gala
 			update_inserter_indices ();
 		}
 
+		/**
+		 * Removes an icon group "in place".
+		 * When initially dragging an icon group we remove
+		 * it and it's previous WorkspaceInsertThumb. This would make
+		 * the container immediately reallocate and fill the empty space
+		 * with right-most IconGroups.
+		 * 
+		 * We don't want that until the IconGroup 
+		 * leaves the expanded WorkspaceInsertThumb.
+		 */
+		public void remove_group_in_place (IconGroup group)
+		{
+			var deleted_thumb = (WorkspaceInsertThumb) group.get_previous_sibling ();
+			var deleted_placeholder_thumb = (WorkspaceInsertThumb) group.get_next_sibling ();
+
+			remove_group (group);
+
+			/**
+			 * We will account for that empty space
+			 * by manually expanding the next WorkspaceInsertThumb with the
+			 * width we deleted. Because the IconGroup is still hovering over
+			 * the expanded thumb, we will also update the drag & drop action
+			 * of IconGroup on that.
+			 */
+			float deleted_width = deleted_thumb.get_width () + group.get_width ();
+			deleted_placeholder_thumb.expanded = true;
+			deleted_placeholder_thumb.width += deleted_width;
+			group.set_hovered_actor (deleted_placeholder_thumb);
+		}
+
+		public void reset_thumbs (int delay)
+		{
+			foreach (var child in get_children ()) {
+				unowned WorkspaceInsertThumb thumb = child as WorkspaceInsertThumb;
+				if (thumb != null) {
+					thumb.delay = delay;
+					thumb.destroy_all_children ();
+				}
+			}
+		}
+
 		void expanded_changed (ParamSpec param)
 		{
-			request_reposition ();
+			request_reposition (true);
 		}
 
 		/**

src/Widgets/MultitaskingView.vala

@@ -64,7 +64,7 @@ namespace Gala
 			workspaces.set_easing_mode (AnimationMode.EASE_OUT_QUAD);
 
 			icon_groups = new IconGroupContainer (screen);
-			icon_groups.request_reposition.connect (() => reposition_icon_groups (true));
+			icon_groups.request_reposition.connect ((animate) => reposition_icon_groups (animate));
 
 			dock_clones = new Actor ();
 
@@ -77,6 +77,7 @@ namespace Gala
 
 			screen.workspace_added.connect (add_workspace);
 			screen.workspace_removed.connect (remove_workspace);
+			screen.workspaces_reordered.connect (() => update_positions (false));
 			screen.workspace_switched.connect_after ((from, to, direction) => {
 				update_positions (opened);
 			});
@@ -311,7 +312,9 @@ namespace Gala
 			workspace.window_selected.disconnect (window_selected);
 			workspace.selected.disconnect (activate_workspace);
 
-			icon_groups.remove_group (workspace.icon_group);
+			if (icon_groups.contains (workspace.icon_group)) {
+				icon_groups.remove_group (workspace.icon_group);
+			}
 
 			workspace.destroy ();
 

src/Widgets/WindowClone.vala

@@ -590,7 +590,7 @@ namespace Gala
 
 			var scale = hovered ? 0.4 : 1.0;
 			var opacity = hovered ? 0 : 255;
-			var duration = hovered && insert_thumb != null ? WorkspaceInsertThumb.EXPAND_DELAY : 100;
+			var duration = hovered && insert_thumb != null ? insert_thumb.delay : 100;
 
 			window_icon.save_easing_state ();
 

src/Widgets/WorkspaceClone.vala

@@ -165,7 +165,7 @@ namespace Gala
 
 			var background_drop_action = new DragDropAction (DragDropActionType.DESTINATION, "multitaskingview-window");
 			background.add_action (background_drop_action);
-			background_drop_action.crossed.connect ((hovered) => {
+			background_drop_action.crossed.connect ((target, hovered) => {
 				if (!hovered && hover_activate_timeout != 0) {
 					Source.remove (hover_activate_timeout);
 					hover_activate_timeout = 0;