Allow to dnd a window icon to the new workspace item (#509)

Author: leolost2605

src/DBus/WindowDragManager.vala

@@ -15,7 +15,7 @@ public class Dock.WindowDragManager : Object {
     public Gtk.Window dock_window { get; construct; }
 
     private Window? current_window = null;
-    private WorkspaceIconGroup? current_icon_group = null;
+    private WorkspaceItem? current_workspace_item = null;
 
     private WindowDragProvider provider;
 
@@ -48,55 +48,55 @@ public class Dock.WindowDragManager : Object {
             return;
         }
 
-        var icon_group = find_icon_group (x, y);
+        var workspace_item = find_workspace_item (x, y);
 
-        if (icon_group == current_icon_group) {
+        if (workspace_item == current_workspace_item) {
             return;
         }
 
-        if (current_icon_group != null) {
-            current_icon_group.window_left ();
+        if (current_workspace_item != null) {
+            current_workspace_item.window_left ();
         }
 
-        current_icon_group = icon_group;
+        current_workspace_item = workspace_item;
 
-        if (current_icon_group != null) {
-            current_icon_group.window_entered (current_window);
+        if (current_workspace_item != null) {
+            current_workspace_item.window_entered (current_window);
         }
     }
 
-    private WorkspaceIconGroup? find_icon_group (int x, int y) {
+    private WorkspaceItem? find_workspace_item (int x, int y) {
         double root_x, root_y;
         dock_window.get_surface_transform (out root_x, out root_y);
 
         var widget = dock_window.pick (x - root_x, y - root_y, DEFAULT);
 
-        while (!(widget is WorkspaceIconGroup) && widget != null) {
+        while (!(widget is WorkspaceItem) && widget != null) {
             widget = widget.get_parent ();
         }
 
-        if (widget is WorkspaceIconGroup) {
-            return (WorkspaceIconGroup) widget;
+        if (widget is WorkspaceItem) {
+            return (WorkspaceItem) widget;
         }
 
         return null;
     }
 
     private void on_leave () {
-        if (current_icon_group != null) {
-            current_icon_group.window_left ();
-            current_icon_group = null;
+        if (current_workspace_item != null) {
+            current_workspace_item.window_left ();
+            current_workspace_item = null;
         }
 
         current_window = null;
     }
 
     private void on_dropped () {
-        if (current_icon_group != null && current_window != null &&
-            current_icon_group.workspace.index != current_window.workspace_index
+        if (current_workspace_item != null && current_window != null &&
+            current_workspace_item.workspace_index != current_window.workspace_index
         ) {
             WindowSystem.get_default ().move_window_to_workspace.begin (
-                current_window.uid, current_icon_group.workspace.index
+                current_window.uid, current_workspace_item.workspace_index
             );
         }
     }

src/WorkspaceSystem/DynamicWorkspaceItem.vala

@@ -3,21 +3,25 @@
  * SPDX-FileCopyrightText: 2025 elementary, Inc. (https://elementary.io)
  */
 
-public class Dock.DynamicWorkspaceIcon : ContainerItem {
+public class Dock.DynamicWorkspaceIcon : ContainerItem, WorkspaceItem {
+    public int workspace_index { get { return WorkspaceSystem.get_default ().workspaces.length; } }
+
+    private Gtk.Image image;
+
     public DynamicWorkspaceIcon () {
         Object (disallow_dnd: true, group: Group.WORKSPACE);
     }
 
     construct {
         var keybinding_settings = new GLib.Settings ("io.elementary.desktop.wm.keybindings");
 
-        var add_image = new Gtk.Image.from_icon_name ("list-add-symbolic") {
+        image = new Gtk.Image.from_icon_name ("list-add-symbolic") {
             hexpand = true,
             vexpand = true
         };
-        add_image.add_css_class ("add-image");
+        image.add_css_class ("add-image");
 
-        child = add_image;
+        child = image;
         tooltip_text = Granite.markup_accel_tooltip (
             keybinding_settings.get_strv ("switch-to-workspace-last"),
             _("New Workspace")
@@ -28,7 +32,7 @@ public class Dock.DynamicWorkspaceIcon : ContainerItem {
         WindowSystem.get_default ().notify["active-workspace"].connect (update_active_state);
 
         dock_settings.bind_with_mapping (
-            "icon-size", add_image, "pixel_size", DEFAULT | GET,
+            "icon-size", image, "pixel_size", DEFAULT | GET,
             (value, variant, user_data) => {
                 var icon_size = variant.get_int32 ();
                 value.set_int (icon_size / 2);
@@ -65,4 +69,12 @@ public class Dock.DynamicWorkspaceIcon : ContainerItem {
             warning ("Couldn't switch to new workspace: %s", e.message);
         }
     }
+
+    public void window_entered (Window window) {
+        image.gicon = window.icon;
+    }
+
+    public void window_left () {
+        image.icon_name = "list-add-symbolic";
+    }
 }

src/WorkspaceSystem/IconGroup.vala

@@ -3,11 +3,13 @@
  * SPDX-FileCopyrightText: 2025 elementary, Inc. (https://elementary.io)
  */
 
-public class Dock.WorkspaceIconGroup : BaseIconGroup {
+public class Dock.WorkspaceIconGroup : BaseIconGroup, WorkspaceItem {
     public Workspace workspace { get; construct; }
 
     public GLib.ListStore additional_icons { private get; construct; }
 
+    public int workspace_index { get { return workspace.index; } }
+
     public WorkspaceIconGroup (Workspace workspace) {
         var additional_icons = new GLib.ListStore (typeof (GLib.Icon));
 

src/WorkspaceSystem/WorkspaceItem.vala

@@ -0,0 +1,13 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0
+ * SPDX-FileCopyrightText: 2025 elementary, Inc. (https://elementary.io)
+ *
+ * Authored by: Leonhard Kargl <[email protected]>
+ */
+
+public interface Dock.WorkspaceItem : Object {
+    public abstract int workspace_index { get; }
+
+    public abstract void window_entered (Window window);
+    public abstract void window_left ();
+}

src/meson.build

@@ -27,6 +27,7 @@ sources = [
     'WorkspaceSystem' / 'DynamicWorkspaceItem.vala',
     'WorkspaceSystem' / 'IconGroup.vala',
     'WorkspaceSystem' / 'Workspace.vala',
+    'WorkspaceSystem' / 'WorkspaceItem.vala',
     'WorkspaceSystem' / 'WorkspaceSystem.vala'
 ]