Adding upstream version 43.9.upstream/43.9upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1134 insertions, 0 deletions

diff --git a/js/ui/altTab.js b/js/ui/altTab.js
new file mode 100644
index 0000000..a3daebc
--- /dev/null
+++ b/js/ui/altTab.js
@@ -0,0 +1,1134 @@
+// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
+/* exported AppSwitcherPopup, GroupCyclerPopup, WindowSwitcherPopup,
+            WindowCyclerPopup */
+
+const { Atk, Clutter, Gio, GLib, GObject, Meta, Shell, St } = imports.gi;
+
+const Main = imports.ui.main;
+const SwitcherPopup = imports.ui.switcherPopup;
+
+var APP_ICON_HOVER_TIMEOUT = 200; // milliseconds
+
+var THUMBNAIL_DEFAULT_SIZE = 256;
+var THUMBNAIL_POPUP_TIME = 500; // milliseconds
+var THUMBNAIL_FADE_TIME = 100; // milliseconds
+
+var WINDOW_PREVIEW_SIZE = 128;
+var APP_ICON_SIZE = 96;
+var APP_ICON_SIZE_SMALL = 48;
+
+const baseIconSizes = [96, 64, 48, 32, 22];
+
+var AppIconMode = {
+    THUMBNAIL_ONLY: 1,
+    APP_ICON_ONLY: 2,
+    BOTH: 3,
+};
+
+function _createWindowClone(window, size) {
+    let [width, height] = window.get_size();
+    let scale = Math.min(1.0, size / width, size / height);
+    return new Clutter.Clone({
+        source: window,
+        width: width * scale,
+        height: height * scale,
+        x_align: Clutter.ActorAlign.CENTER,
+        y_align: Clutter.ActorAlign.CENTER,
+        // usual hack for the usual bug in ClutterBinLayout...
+        x_expand: true,
+        y_expand: true,
+    });
+}
+
+function getWindows(workspace) {
+    // We ignore skip-taskbar windows in switchers, but if they are attached
+    // to their parent, their position in the MRU list may be more appropriate
+    // than the parent; so start with the complete list ...
+    let windows = global.display.get_tab_list(Meta.TabList.NORMAL_ALL,
+                                              workspace);
+    // ... map windows to their parent where appropriate ...
+    return windows.map(w => {
+        return w.is_attached_dialog() ? w.get_transient_for() : w;
+    // ... and filter out skip-taskbar windows and duplicates
+    }).filter((w, i, a) => !w.skip_taskbar && a.indexOf(w) == i);
+}
+
+var AppSwitcherPopup = GObject.registerClass(
+class AppSwitcherPopup extends SwitcherPopup.SwitcherPopup {
+    _init() {
+        super._init();
+
+        this._thumbnails = null;
+        this._thumbnailTimeoutId = 0;
+        this._currentWindow = -1;
+
+        this.thumbnailsVisible = false;
+
+        let apps = Shell.AppSystem.get_default().get_running();
+
+        this._switcherList = new AppSwitcher(apps, this);
+        this._items = this._switcherList.icons;
+    }
+
+    vfunc_allocate(box) {
+        super.vfunc_allocate(box);
+
+        // Allocate the thumbnails
+        // We try to avoid overflowing the screen so we base the resulting size on
+        // those calculations
+        if (this._thumbnails) {
+            let childBox = this._switcherList.get_allocation_box();
+            let primary = Main.layoutManager.primaryMonitor;
+
+            let leftPadding = this.get_theme_node().get_padding(St.Side.LEFT);
+            let rightPadding = this.get_theme_node().get_padding(St.Side.RIGHT);
+            let bottomPadding = this.get_theme_node().get_padding(St.Side.BOTTOM);
+            let hPadding = leftPadding + rightPadding;
+
+            let icon = this._items[this._selectedIndex];
+            let [posX] = icon.get_transformed_position();
+            let thumbnailCenter = posX + icon.width / 2;
+            let [, childNaturalWidth] = this._thumbnails.get_preferred_width(-1);
+            childBox.x1 = Math.max(primary.x + leftPadding, Math.floor(thumbnailCenter - childNaturalWidth / 2));
+            if (childBox.x1 + childNaturalWidth > primary.x + primary.width - hPadding) {
+                let offset = childBox.x1 + childNaturalWidth - primary.width + hPadding;
+                childBox.x1 = Math.max(primary.x + leftPadding, childBox.x1 - offset - hPadding);
+            }
+
+            let spacing = this.get_theme_node().get_length('spacing');
+
+            childBox.x2 = childBox.x1 +  childNaturalWidth;
+            if (childBox.x2 > primary.x + primary.width - rightPadding)
+                childBox.x2 = primary.x + primary.width - rightPadding;
+            childBox.y1 = this._switcherList.allocation.y2 + spacing;
+            this._thumbnails.addClones(primary.y + primary.height - bottomPadding - childBox.y1);
+            let [, childNaturalHeight] = this._thumbnails.get_preferred_height(-1);
+            childBox.y2 = childBox.y1 + childNaturalHeight;
+            this._thumbnails.allocate(childBox);
+        }
+    }
+
+    _initialSelection(backward, binding) {
+        if (binding == 'switch-group') {
+            if (backward)
+                this._select(0, this._items[0].cachedWindows.length - 1);
+            else if (this._items[0].cachedWindows.length > 1)
+                this._select(0, 1);
+            else
+                this._select(0, 0);
+        } else if (binding == 'switch-group-backward') {
+            this._select(0, this._items[0].cachedWindows.length - 1);
+        } else if (binding == 'switch-applications-backward') {
+            this._select(this._items.length - 1);
+        } else if (this._items.length == 1) {
+            this._select(0);
+        } else if (backward) {
+            this._select(this._items.length - 1);
+        } else {
+            this._select(1);
+        }
+    }
+
+    _nextWindow() {
+        // We actually want the second window if we're in the unset state
+        if (this._currentWindow == -1)
+            this._currentWindow = 0;
+        return SwitcherPopup.mod(this._currentWindow + 1,
+                                 this._items[this._selectedIndex].cachedWindows.length);
+    }
+
+    _previousWindow() {
+        // Also assume second window here
+        if (this._currentWindow == -1)
+            this._currentWindow = 1;
+        return SwitcherPopup.mod(this._currentWindow - 1,
+                                 this._items[this._selectedIndex].cachedWindows.length);
+    }
+
+    _closeAppWindow(appIndex, windowIndex) {
+        let appIcon = this._items[appIndex];
+        if (!appIcon)
+            return;
+
+        let window = appIcon.cachedWindows[windowIndex];
+        if (!window)
+            return;
+
+        window.delete(global.get_current_time());
+    }
+
+    _quitApplication(appIndex) {
+        let appIcon = this._items[appIndex];
+        if (!appIcon)
+            return;
+
+        appIcon.app.request_quit();
+    }
+
+    _keyPressHandler(keysym, action) {
+        const rtl = Clutter.get_default_text_direction() === Clutter.TextDirection.RTL;
+        if (action == Meta.KeyBindingAction.SWITCH_GROUP) {
+            if (!this._thumbnailsFocused)
+                this._select(this._selectedIndex, 0);
+            else
+                this._select(this._selectedIndex, this._nextWindow());
+        } else if (action == Meta.KeyBindingAction.SWITCH_GROUP_BACKWARD) {
+            this._select(this._selectedIndex, this._previousWindow());
+        } else if (action == Meta.KeyBindingAction.SWITCH_APPLICATIONS) {
+            this._select(this._next());
+        } else if (action == Meta.KeyBindingAction.SWITCH_APPLICATIONS_BACKWARD) {
+            this._select(this._previous());
+        } else if (keysym == Clutter.KEY_q || keysym === Clutter.KEY_Q) {
+            this._quitApplication(this._selectedIndex);
+        } else if (this._thumbnailsFocused) {
+            if (keysym === Clutter.KEY_Left)
+                this._select(this._selectedIndex, rtl ? this._nextWindow() : this._previousWindow());
+            else if (keysym === Clutter.KEY_Right)
+                this._select(this._selectedIndex, rtl ? this._previousWindow() : this._nextWindow());
+            else if (keysym === Clutter.KEY_Up)
+                this._select(this._selectedIndex, null, true);
+            else if (keysym === Clutter.KEY_w || keysym === Clutter.KEY_W || keysym === Clutter.KEY_F4)
+                this._closeAppWindow(this._selectedIndex, this._currentWindow);
+            else
+                return Clutter.EVENT_PROPAGATE;
+        } else if (keysym == Clutter.KEY_Left) {
+            this._select(rtl ? this._next() : this._previous());
+        } else if (keysym == Clutter.KEY_Right) {
+            this._select(rtl ? this._previous() : this._next());
+        } else if (keysym == Clutter.KEY_Down) {
+            this._select(this._selectedIndex, 0);
+        } else {
+            return Clutter.EVENT_PROPAGATE;
+        }
+
+        return Clutter.EVENT_STOP;
+    }
+
+    _scrollHandler(direction) {
+        if (direction == Clutter.ScrollDirection.UP) {
+            if (this._thumbnailsFocused) {
+                if (this._currentWindow == 0 || this._currentWindow == -1)
+                    this._select(this._previous());
+                else
+                    this._select(this._selectedIndex, this._previousWindow());
+            } else {
+                let nwindows = this._items[this._selectedIndex].cachedWindows.length;
+                if (nwindows > 1)
+                    this._select(this._selectedIndex, nwindows - 1);
+                else
+                    this._select(this._previous());
+            }
+        } else if (direction == Clutter.ScrollDirection.DOWN) {
+            if (this._thumbnailsFocused) {
+                if (this._currentWindow == this._items[this._selectedIndex].cachedWindows.length - 1)
+                    this._select(this._next());
+                else
+                    this._select(this._selectedIndex, this._nextWindow());
+            } else {
+                let nwindows = this._items[this._selectedIndex].cachedWindows.length;
+                if (nwindows > 1)
+                    this._select(this._selectedIndex, 0);
+                else
+                    this._select(this._next());
+            }
+        }
+    }
+
+    _itemActivatedHandler(n) {
+        // If the user clicks on the selected app, activate the
+        // selected window; otherwise (eg, they click on an app while
+        // !mouseActive) activate the clicked-on app.
+        if (n == this._selectedIndex && this._currentWindow >= 0)
+            this._select(n, this._currentWindow);
+        else
+            this._select(n);
+    }
+
+    _windowActivated(thumbnailSwitcher, n) {
+        let appIcon = this._items[this._selectedIndex];
+        Main.activateWindow(appIcon.cachedWindows[n]);
+        this.fadeAndDestroy();
+    }
+
+    _windowEntered(thumbnailSwitcher, n) {
+        if (!this.mouseActive)
+            return;
+
+        this._select(this._selectedIndex, n);
+    }
+
+    _windowRemoved(thumbnailSwitcher, n) {
+        let appIcon = this._items[this._selectedIndex];
+        if (!appIcon)
+            return;
+
+        if (appIcon.cachedWindows.length > 0) {
+            let newIndex = Math.min(n, appIcon.cachedWindows.length - 1);
+            this._select(this._selectedIndex, newIndex);
+        }
+    }
+
+    _finish(timestamp) {
+        let appIcon = this._items[this._selectedIndex];
+        if (this._currentWindow < 0)
+            appIcon.app.activate_window(appIcon.cachedWindows[0], timestamp);
+        else if (appIcon.cachedWindows[this._currentWindow])
+            Main.activateWindow(appIcon.cachedWindows[this._currentWindow], timestamp);
+
+        super._finish(timestamp);
+    }
+
+    _onDestroy() {
+        if (this._thumbnailTimeoutId != 0)
+            GLib.source_remove(this._thumbnailTimeoutId);
+
+        super._onDestroy();
+    }
+
+    /**
+     * _select:
+     * @param {number} app: index of the app to select
+     * @param {number=} window: index of which of @app's windows to select
+     * @param {bool} forceAppFocus: optional flag, see below
+     *
+     * Selects the indicated @app, and optional @window, and sets
+     * this._thumbnailsFocused appropriately to indicate whether the
+     * arrow keys should act on the app list or the thumbnail list.
+     *
+     * If @app is specified and @window is unspecified or %null, then
+     * the app is highlighted (ie, given a light background), and the
+     * current thumbnail list, if any, is destroyed. If @app has
+     * multiple windows, and @forceAppFocus is not %true, then a
+     * timeout is started to open a thumbnail list.
+     *
+     * If @app and @window are specified (and @forceAppFocus is not),
+     * then @app will be outlined, a thumbnail list will be created
+     * and focused (if it hasn't been already), and the @window'th
+     * window in it will be highlighted.
+     *
+     * If @app and @window are specified and @forceAppFocus is %true,
+     * then @app will be highlighted, and @window outlined, and the
+     * app list will have the keyboard focus.
+     */
+    _select(app, window, forceAppFocus) {
+        if (app != this._selectedIndex || window == null) {
+            if (this._thumbnails)
+                this._destroyThumbnails();
+        }
+
+        if (this._thumbnailTimeoutId != 0) {
+            GLib.source_remove(this._thumbnailTimeoutId);
+            this._thumbnailTimeoutId = 0;
+        }
+
+        this._thumbnailsFocused = (window != null) && !forceAppFocus;
+
+        this._selectedIndex = app;
+        this._currentWindow = window ? window : -1;
+        this._switcherList.highlight(app, this._thumbnailsFocused);
+
+        if (window != null) {
+            if (!this._thumbnails)
+                this._createThumbnails();
+            this._currentWindow = window;
+            this._thumbnails.highlight(window, forceAppFocus);
+        } else if (this._items[this._selectedIndex].cachedWindows.length > 1 &&
+                   !forceAppFocus) {
+            this._thumbnailTimeoutId = GLib.timeout_add(
+                GLib.PRIORITY_DEFAULT,
+                THUMBNAIL_POPUP_TIME,
+                this._timeoutPopupThumbnails.bind(this));
+            GLib.Source.set_name_by_id(this._thumbnailTimeoutId, '[gnome-shell] this._timeoutPopupThumbnails');
+        }
+    }
+
+    _timeoutPopupThumbnails() {
+        if (!this._thumbnails)
+            this._createThumbnails();
+        this._thumbnailTimeoutId = 0;
+        this._thumbnailsFocused = false;
+        return GLib.SOURCE_REMOVE;
+    }
+
+    _destroyThumbnails() {
+        let thumbnailsActor = this._thumbnails;
+        this._thumbnails.ease({
+            opacity: 0,
+            duration: THUMBNAIL_FADE_TIME,
+            mode: Clutter.AnimationMode.EASE_OUT_QUAD,
+            onComplete: () => {
+                thumbnailsActor.destroy();
+                this.thumbnailsVisible = false;
+            },
+        });
+        this._thumbnails = null;
+        this._switcherList.removeAccessibleState(this._selectedIndex, Atk.StateType.EXPANDED);
+    }
+
+    _createThumbnails() {
+        this._thumbnails = new ThumbnailSwitcher(this._items[this._selectedIndex].cachedWindows);
+        this._thumbnails.connect('item-activated', this._windowActivated.bind(this));
+        this._thumbnails.connect('item-entered', this._windowEntered.bind(this));
+        this._thumbnails.connect('item-removed', this._windowRemoved.bind(this));
+        this._thumbnails.connect('destroy', () => {
+            this._thumbnails = null;
+            this._thumbnailsFocused = false;
+        });
+
+        this.add_actor(this._thumbnails);
+
+        // Need to force an allocation so we can figure out whether we
+        // need to scroll when selecting
+        this._thumbnails.get_allocation_box();
+
+        this._thumbnails.opacity = 0;
+        this._thumbnails.ease({
+            opacity: 255,
+            duration: THUMBNAIL_FADE_TIME,
+            mode: Clutter.AnimationMode.EASE_OUT_QUAD,
+            onComplete: () => {
+                this.thumbnailsVisible = true;
+            },
+        });
+
+        this._switcherList.addAccessibleState(this._selectedIndex, Atk.StateType.EXPANDED);
+    }
+});
+
+var CyclerHighlight = GObject.registerClass(
+class CyclerHighlight extends St.Widget {
+    _init() {
+        super._init({ layout_manager: new Clutter.BinLayout() });
+        this._window = null;
+
+        this._clone = new Clutter.Clone();
+        this.add_actor(this._clone);
+
+        this._highlight = new St.Widget({ style_class: 'cycler-highlight' });
+        this.add_actor(this._highlight);
+
+        let coordinate = Clutter.BindCoordinate.ALL;
+        let constraint = new Clutter.BindConstraint({ coordinate });
+        this._clone.bind_property('source', constraint, 'source', 0);
+
+        this.add_constraint(constraint);
+
+        this.connect('destroy', this._onDestroy.bind(this));
+    }
+
+    set window(w) {
+        if (this._window == w)
+            return;
+
+        this._window?.disconnectObject(this);
+
+        this._window = w;
+
+        if (this._clone.source)
+            this._clone.source.sync_visibility();
+
+        const windowActor = this._window?.get_compositor_private() ?? null;
+
+        if (windowActor)
+            windowActor.hide();
+
+        this._clone.source = windowActor;
+
+        if (this._window) {
+            this._onSizeChanged();
+            this._window.connectObject('size-changed',
+                this._onSizeChanged.bind(this), this);
+        } else {
+            this._highlight.set_size(0, 0);
+            this._highlight.hide();
+        }
+    }
+
+    _onSizeChanged() {
+        const bufferRect = this._window.get_buffer_rect();
+        const rect = this._window.get_frame_rect();
+        this._highlight.set_size(rect.width, rect.height);
+        this._highlight.set_position(
+            rect.x - bufferRect.x,
+            rect.y - bufferRect.y);
+        this._highlight.show();
+    }
+
+    _onDestroy() {
+        this.window = null;
+    }
+});
+
+// We don't show an actual popup, so just provide what SwitcherPopup
+// expects instead of inheriting from SwitcherList
+var CyclerList = GObject.registerClass({
+    Signals: {
+        'item-activated': { param_types: [GObject.TYPE_INT] },
+        'item-entered': { param_types: [GObject.TYPE_INT] },
+        'item-removed': { param_types: [GObject.TYPE_INT] },
+        'item-highlighted': { param_types: [GObject.TYPE_INT] },
+    },
+}, class CyclerList extends St.Widget {
+    highlight(index, _justOutline) {
+        this.emit('item-highlighted', index);
+    }
+});
+
+var CyclerPopup = GObject.registerClass({
+    GTypeFlags: GObject.TypeFlags.ABSTRACT,
+}, class CyclerPopup extends SwitcherPopup.SwitcherPopup {
+    _init() {
+        super._init();
+
+        this._items = this._getWindows();
+
+        this._highlight = new CyclerHighlight();
+        global.window_group.add_actor(this._highlight);
+
+        this._switcherList = new CyclerList();
+        this._switcherList.connect('item-highlighted', (list, index) => {
+            this._highlightItem(index);
+        });
+    }
+
+    _highlightItem(index, _justOutline) {
+        this._highlight.window = this._items[index];
+        global.window_group.set_child_above_sibling(this._highlight, null);
+    }
+
+    _finish() {
+        let window = this._items[this._selectedIndex];
+        let ws = window.get_workspace();
+        let workspaceManager = global.workspace_manager;
+        let activeWs = workspaceManager.get_active_workspace();
+
+        if (window.minimized) {
+            Main.wm.skipNextEffect(window.get_compositor_private());
+            window.unminimize();
+        }
+
+        if (activeWs == ws) {
+            Main.activateWindow(window);
+        } else {
+            // If the selected window is on a different workspace, we don't
+            // want it to disappear, then slide in with the workspace; instead,
+            // always activate it on the active workspace ...
+            activeWs.activate_with_focus(window, global.get_current_time());
+
+            // ... then slide it over to the original workspace if necessary
+            Main.wm.actionMoveWindow(window, ws);
+        }
+
+        super._finish();
+    }
+
+    _onDestroy() {
+        this._highlight.destroy();
+
+        super._onDestroy();
+    }
+});
+
+
+var GroupCyclerPopup = GObject.registerClass(
+class GroupCyclerPopup extends CyclerPopup {
+    _init() {
+        this._settings = new Gio.Settings({ schema_id: 'org.gnome.shell.app-switcher' });
+        super._init();
+    }
+
+    _getWindows() {
+        let app = Shell.WindowTracker.get_default().focus_app;
+        let appWindows = app?.get_windows() ?? [];
+
+        if (this._settings.get_boolean('current-workspace-only')) {
+            const workspaceManager = global.workspace_manager;
+            const workspace = workspaceManager.get_active_workspace();
+            appWindows = appWindows.filter(
+                window => window.located_on_workspace(workspace));
+        }
+
+        return appWindows;
+    }
+
+    _keyPressHandler(keysym, action) {
+        if (action == Meta.KeyBindingAction.CYCLE_GROUP)
+            this._select(this._next());
+        else if (action == Meta.KeyBindingAction.CYCLE_GROUP_BACKWARD)
+            this._select(this._previous());
+        else
+            return Clutter.EVENT_PROPAGATE;
+
+        return Clutter.EVENT_STOP;
+    }
+});
+
+var WindowSwitcherPopup = GObject.registerClass(
+class WindowSwitcherPopup extends SwitcherPopup.SwitcherPopup {
+    _init() {
+        super._init();
+        this._settings = new Gio.Settings({ schema_id: 'org.gnome.shell.window-switcher' });
+
+        let windows = this._getWindowList();
+
+        let mode = this._settings.get_enum('app-icon-mode');
+        this._switcherList = new WindowSwitcher(windows, mode);
+        this._items = this._switcherList.icons;
+    }
+
+    _getWindowList() {
+        let workspace = null;
+
+        if (this._settings.get_boolean('current-workspace-only')) {
+            let workspaceManager = global.workspace_manager;
+
+            workspace = workspaceManager.get_active_workspace();
+        }
+
+        return getWindows(workspace);
+    }
+
+    _closeWindow(windowIndex) {
+        let windowIcon = this._items[windowIndex];
+        if (!windowIcon)
+            return;
+
+        windowIcon.window.delete(global.get_current_time());
+    }
+
+    _keyPressHandler(keysym, action) {
+        const rtl = Clutter.get_default_text_direction() === Clutter.TextDirection.RTL;
+        if (action == Meta.KeyBindingAction.SWITCH_WINDOWS)
+            this._select(this._next());
+        else if (action == Meta.KeyBindingAction.SWITCH_WINDOWS_BACKWARD)
+            this._select(this._previous());
+        else if (keysym == Clutter.KEY_Left)
+            this._select(rtl ? this._next() : this._previous());
+        else if (keysym == Clutter.KEY_Right)
+            this._select(rtl ? this._previous() : this._next());
+        else if (keysym === Clutter.KEY_w || keysym === Clutter.KEY_W || keysym === Clutter.KEY_F4)
+            this._closeWindow(this._selectedIndex);
+        else
+            return Clutter.EVENT_PROPAGATE;
+
+        return Clutter.EVENT_STOP;
+    }
+
+    _finish() {
+        Main.activateWindow(this._items[this._selectedIndex].window);
+
+        super._finish();
+    }
+});
+
+var WindowCyclerPopup = GObject.registerClass(
+class WindowCyclerPopup extends CyclerPopup {
+    _init() {
+        this._settings = new Gio.Settings({ schema_id: 'org.gnome.shell.window-switcher' });
+        super._init();
+    }
+
+    _getWindows() {
+        let workspace = null;
+
+        if (this._settings.get_boolean('current-workspace-only')) {
+            let workspaceManager = global.workspace_manager;
+
+            workspace = workspaceManager.get_active_workspace();
+        }
+
+        return getWindows(workspace);
+    }
+
+    _keyPressHandler(keysym, action) {
+        if (action == Meta.KeyBindingAction.CYCLE_WINDOWS)
+            this._select(this._next());
+        else if (action == Meta.KeyBindingAction.CYCLE_WINDOWS_BACKWARD)
+            this._select(this._previous());
+        else
+            return Clutter.EVENT_PROPAGATE;
+
+        return Clutter.EVENT_STOP;
+    }
+});
+
+var AppIcon = GObject.registerClass(
+class AppIcon extends St.BoxLayout {
+    _init(app) {
+        super._init({
+            style_class: 'alt-tab-app',
+            vertical: true,
+        });
+
+        this.app = app;
+        this.icon = null;
+        this._iconBin = new St.Bin();
+
+        this.add_child(this._iconBin);
+        this.label = new St.Label({
+            text: this.app.get_name(),
+            x_align: Clutter.ActorAlign.CENTER,
+        });
+        this.add_child(this.label);
+    }
+
+    // eslint-disable-next-line camelcase
+    set_size(size) {
+        this.icon = this.app.create_icon_texture(size);
+        this._iconBin.child = this.icon;
+    }
+});
+
+var AppSwitcher = GObject.registerClass(
+class AppSwitcher extends SwitcherPopup.SwitcherList {
+    _init(apps, altTabPopup) {
+        super._init(true);
+
+        this.icons = [];
+        this._arrows = [];
+
+        let windowTracker = Shell.WindowTracker.get_default();
+        let settings = new Gio.Settings({ schema_id: 'org.gnome.shell.app-switcher' });
+
+        let workspace = null;
+        if (settings.get_boolean('current-workspace-only')) {
+            let workspaceManager = global.workspace_manager;
+
+            workspace = workspaceManager.get_active_workspace();
+        }
+
+        let allWindows = getWindows(workspace);
+
+        // Construct the AppIcons, add to the popup
+        for (let i = 0; i < apps.length; i++) {
+            let appIcon = new AppIcon(apps[i]);
+            // Cache the window list now; we don't handle dynamic changes here,
+            // and we don't want to be continually retrieving it
+            appIcon.cachedWindows = allWindows.filter(
+                w => windowTracker.get_window_app(w) === appIcon.app);
+            if (appIcon.cachedWindows.length > 0)
+                this._addIcon(appIcon);
+        }
+
+        this._altTabPopup = altTabPopup;
+        this._delayedHighlighted = -1;
+        this._mouseTimeOutId = 0;
+
+        this.connect('destroy', this._onDestroy.bind(this));
+    }
+
+    _onDestroy() {
+        if (this._mouseTimeOutId != 0)
+            GLib.source_remove(this._mouseTimeOutId);
+
+        this.icons.forEach(
+            icon => icon.app.disconnectObject(this));
+    }
+
+    _setIconSize() {
+        let j = 0;
+        while (this._items.length > 1 && this._items[j].style_class != 'item-box')
+            j++;
+
+        let themeNode = this._items[j].get_theme_node();
+        this._list.ensure_style();
+
+        let iconPadding = themeNode.get_horizontal_padding();
+        let iconBorder = themeNode.get_border_width(St.Side.LEFT) + themeNode.get_border_width(St.Side.RIGHT);
+        let [, labelNaturalHeight] = this.icons[j].label.get_preferred_height(-1);
+        let iconSpacing = labelNaturalHeight + iconPadding + iconBorder;
+        let totalSpacing = this._list.spacing * (this._items.length - 1);
+
+        // We just assume the whole screen here due to weirdness happening with the passed width
+        let primary = Main.layoutManager.primaryMonitor;
+        let parentPadding = this.get_parent().get_theme_node().get_horizontal_padding();
+        let availWidth = primary.width - parentPadding - this.get_theme_node().get_horizontal_padding();
+
+        let scaleFactor = St.ThemeContext.get_for_stage(global.stage).scale_factor;
+        let iconSizes = baseIconSizes.map(s => s * scaleFactor);
+        let iconSize = baseIconSizes[0];
+
+        if (this._items.length > 1) {
+            for (let i =  0; i < baseIconSizes.length; i++) {
+                iconSize = baseIconSizes[i];
+                let height = iconSizes[i] + iconSpacing;
+                let w = height * this._items.length + totalSpacing;
+                if (w <= availWidth)
+                    break;
+            }
+        }
+
+        this._iconSize = iconSize;
+
+        for (let i = 0; i < this.icons.length; i++) {
+            if (this.icons[i].icon != null)
+                break;
+            this.icons[i].set_size(iconSize);
+        }
+    }
+
+    vfunc_get_preferred_height(forWidth) {
+        if (!this._iconSize)
+            this._setIconSize();
+
+        return super.vfunc_get_preferred_height(forWidth);
+    }
+
+    vfunc_allocate(box) {
+        // Allocate the main list items
+        super.vfunc_allocate(box);
+
+        let contentBox = this.get_theme_node().get_content_box(box);
+
+        let arrowHeight = Math.floor(this.get_theme_node().get_padding(St.Side.BOTTOM) / 3);
+        let arrowWidth = arrowHeight * 2;
+
+        // Now allocate each arrow underneath its item
+        let childBox = new Clutter.ActorBox();
+        for (let i = 0; i < this._items.length; i++) {
+            let itemBox = this._items[i].allocation;
+            childBox.x1 = contentBox.x1 + Math.floor(itemBox.x1 + (itemBox.x2 - itemBox.x1 - arrowWidth) / 2);
+            childBox.x2 = childBox.x1 + arrowWidth;
+            childBox.y1 = contentBox.y1 + itemBox.y2 + arrowHeight;
+            childBox.y2 = childBox.y1 + arrowHeight;
+            this._arrows[i].allocate(childBox);
+        }
+    }
+
+    // We override SwitcherList's _onItemMotion method to delay
+    // activation when the thumbnail list is open
+    _onItemMotion(item) {
+        if (item === this._items[this._highlighted] ||
+            item === this._items[this._delayedHighlighted])
+            return Clutter.EVENT_PROPAGATE;
+
+        const index = this._items.indexOf(item);
+
+        if (this._mouseTimeOutId !== 0) {
+            GLib.source_remove(this._mouseTimeOutId);
+            this._delayedHighlighted = -1;
+            this._mouseTimeOutId = 0;
+        }
+
+        if (this._altTabPopup.thumbnailsVisible) {
+            this._delayedHighlighted = index;
+            this._mouseTimeOutId = GLib.timeout_add(
+                GLib.PRIORITY_DEFAULT,
+                APP_ICON_HOVER_TIMEOUT,
+                () => {
+                    this._enterItem(index);
+                    this._delayedHighlighted = -1;
+                    this._mouseTimeOutId = 0;
+                    return GLib.SOURCE_REMOVE;
+                });
+            GLib.Source.set_name_by_id(this._mouseTimeOutId, '[gnome-shell] this._enterItem');
+        } else {
+            this._itemEntered(index);
+        }
+
+        return Clutter.EVENT_PROPAGATE;
+    }
+
+    _enterItem(index) {
+        let [x, y] = global.get_pointer();
+        let pickedActor = global.stage.get_actor_at_pos(Clutter.PickMode.ALL, x, y);
+        if (this._items[index].contains(pickedActor))
+            this._itemEntered(index);
+    }
+
+    // We override SwitcherList's highlight() method to also deal with
+    // the AppSwitcher->ThumbnailSwitcher arrows. Apps with only 1 window
+    // will hide their arrows by default, but show them when their
+    // thumbnails are visible (ie, when the app icon is supposed to be
+    // in justOutline mode). Apps with multiple windows will normally
+    // show a dim arrow, but show a bright arrow when they are
+    // highlighted.
+    highlight(n, justOutline) {
+        if (this.icons[this._highlighted]) {
+            if (this.icons[this._highlighted].cachedWindows.length === 1)
+                this._arrows[this._highlighted].hide();
+            else
+                this._arrows[this._highlighted].remove_style_pseudo_class('highlighted');
+        }
+
+        super.highlight(n, justOutline);
+
+        if (this._highlighted !== -1) {
+            if (justOutline && this.icons[this._highlighted].cachedWindows.length === 1)
+                this._arrows[this._highlighted].show();
+            else
+                this._arrows[this._highlighted].add_style_pseudo_class('highlighted');
+        }
+    }
+
+    _addIcon(appIcon) {
+        this.icons.push(appIcon);
+        let item = this.addItem(appIcon, appIcon.label);
+
+        appIcon.app.connectObject('notify::state', app => {
+            if (app.state != Shell.AppState.RUNNING)
+                this._removeIcon(app);
+        }, this);
+
+        let arrow = new St.DrawingArea({ style_class: 'switcher-arrow' });
+        arrow.connect('repaint', () => SwitcherPopup.drawArrow(arrow, St.Side.BOTTOM));
+        this.add_actor(arrow);
+        this._arrows.push(arrow);
+
+        if (appIcon.cachedWindows.length == 1)
+            arrow.hide();
+        else
+            item.add_accessible_state(Atk.StateType.EXPANDABLE);
+    }
+
+    _removeIcon(app) {
+        let index = this.icons.findIndex(icon => {
+            return icon.app == app;
+        });
+        if (index === -1)
+            return;
+
+        this._arrows[index].destroy();
+        this._arrows.splice(index, 1);
+
+        this.icons.splice(index, 1);
+        this.removeItem(index);
+    }
+});
+
+var ThumbnailSwitcher = GObject.registerClass(
+class ThumbnailSwitcher extends SwitcherPopup.SwitcherList {
+    _init(windows) {
+        super._init(false);
+
+        this._labels = [];
+        this._thumbnailBins = [];
+        this._clones = [];
+        this._windows = windows;
+
+        for (let i = 0; i < windows.length; i++) {
+            const box = new St.BoxLayout({
+                style_class: 'thumbnail-box',
+                vertical: true,
+            });
+
+            let bin = new St.Bin({ style_class: 'thumbnail' });
+
+            box.add_actor(bin);
+            this._thumbnailBins.push(bin);
+
+            const title = windows[i].get_title();
+            const name = new St.Label({
+                text: title,
+                // St.Label doesn't support text-align
+                x_align: Clutter.ActorAlign.CENTER,
+            });
+            this._labels.push(name);
+            box.add_actor(name);
+
+            this.addItem(box, name);
+        }
+
+        this.connect('destroy', this._onDestroy.bind(this));
+    }
+
+    addClones(availHeight) {
+        if (!this._thumbnailBins.length)
+            return;
+        let totalPadding = this._items[0].get_theme_node().get_horizontal_padding() + this._items[0].get_theme_node().get_vertical_padding();
+        totalPadding += this.get_theme_node().get_horizontal_padding() + this.get_theme_node().get_vertical_padding();
+        let [, labelNaturalHeight] = this._labels[0].get_preferred_height(-1);
+        let spacing = this._items[0].child.get_theme_node().get_length('spacing');
+        let scaleFactor = St.ThemeContext.get_for_stage(global.stage).scale_factor;
+        let thumbnailSize = THUMBNAIL_DEFAULT_SIZE * scaleFactor;
+
+        availHeight = Math.min(availHeight - labelNaturalHeight - totalPadding - spacing, thumbnailSize);
+        let binHeight = availHeight + this._items[0].get_theme_node().get_vertical_padding() + this.get_theme_node().get_vertical_padding() - spacing;
+        binHeight = Math.min(thumbnailSize, binHeight);
+
+        for (let i = 0; i < this._thumbnailBins.length; i++) {
+            let mutterWindow = this._windows[i].get_compositor_private();
+            if (!mutterWindow)
+                continue;
+
+            let clone = _createWindowClone(mutterWindow, thumbnailSize);
+            this._thumbnailBins[i].set_height(binHeight);
+            this._thumbnailBins[i].add_actor(clone);
+
+            mutterWindow.connectObject('destroy',
+                source => this._removeThumbnail(source, clone), this);
+            this._clones.push(clone);
+        }
+
+        // Make sure we only do this once
+        this._thumbnailBins = [];
+    }
+
+    _removeThumbnail(source, clone) {
+        let index = this._clones.indexOf(clone);
+        if (index === -1)
+            return;
+
+        this._clones.splice(index, 1);
+        this._windows.splice(index, 1);
+        this._labels.splice(index, 1);
+        this.removeItem(index);
+
+        if (this._clones.length > 0)
+            this.highlight(SwitcherPopup.mod(index, this._clones.length));
+        else
+            this.destroy();
+    }
+
+    _onDestroy() {
+        this._clones.forEach(
+            clone => clone?.source.disconnectObject(this));
+    }
+});
+
+var WindowIcon = GObject.registerClass(
+class WindowIcon extends St.BoxLayout {
+    _init(window, mode) {
+        super._init({
+            style_class: 'alt-tab-app',
+            vertical: true,
+        });
+
+        this.window = window;
+
+        this._icon = new St.Widget({ layout_manager: new Clutter.BinLayout() });
+
+        this.add_child(this._icon);
+        this.label = new St.Label({ text: window.get_title() });
+
+        let tracker = Shell.WindowTracker.get_default();
+        this.app = tracker.get_window_app(window);
+
+        let mutterWindow = this.window.get_compositor_private();
+        let size;
+
+        this._icon.destroy_all_children();
+
+        let scaleFactor = St.ThemeContext.get_for_stage(global.stage).scale_factor;
+
+        switch (mode) {
+        case AppIconMode.THUMBNAIL_ONLY:
+            size = WINDOW_PREVIEW_SIZE;
+            this._icon.add_actor(_createWindowClone(mutterWindow, size * scaleFactor));
+            break;
+
+        case AppIconMode.BOTH:
+            size = WINDOW_PREVIEW_SIZE;
+            this._icon.add_actor(_createWindowClone(mutterWindow, size * scaleFactor));
+
+            if (this.app) {
+                this._icon.add_actor(this._createAppIcon(this.app,
+                                                         APP_ICON_SIZE_SMALL));
+            }
+            break;
+
+        case AppIconMode.APP_ICON_ONLY:
+            size = APP_ICON_SIZE;
+            this._icon.add_actor(this._createAppIcon(this.app, size));
+        }
+
+        this._icon.set_size(size * scaleFactor, size * scaleFactor);
+    }
+
+    _createAppIcon(app, size) {
+        let appIcon = app
+            ? app.create_icon_texture(size)
+            : new St.Icon({ icon_name: 'icon-missing', icon_size: size });
+        appIcon.x_expand = appIcon.y_expand = true;
+        appIcon.x_align = appIcon.y_align = Clutter.ActorAlign.END;
+
+        return appIcon;
+    }
+});
+
+var WindowSwitcher = GObject.registerClass(
+class WindowSwitcher extends SwitcherPopup.SwitcherList {
+    _init(windows, mode) {
+        super._init(true);
+
+        this._label = new St.Label({
+            x_align: Clutter.ActorAlign.CENTER,
+            y_align: Clutter.ActorAlign.CENTER,
+        });
+        this.add_actor(this._label);
+
+        this.windows = windows;
+        this.icons = [];
+
+        for (let i = 0; i < windows.length; i++) {
+            let win = windows[i];
+            let icon = new WindowIcon(win, mode);
+
+            this.addItem(icon, icon.label);
+            this.icons.push(icon);
+
+            icon.window.connectObject('unmanaged',
+                window => this._removeWindow(window), this);
+        }
+
+        this.connect('destroy', this._onDestroy.bind(this));
+    }
+
+    _onDestroy() {
+        this.icons.forEach(
+            icon => icon.window.disconnectObject(this));
+    }
+
+    vfunc_get_preferred_height(forWidth) {
+        let [minHeight, natHeight] = super.vfunc_get_preferred_height(forWidth);
+
+        let spacing = this.get_theme_node().get_padding(St.Side.BOTTOM);
+        let [labelMin, labelNat] = this._label.get_preferred_height(-1);
+
+        minHeight += labelMin + spacing;
+        natHeight += labelNat + spacing;
+
+        return [minHeight, natHeight];
+    }
+
+    vfunc_allocate(box) {
+        let themeNode = this.get_theme_node();
+        let contentBox = themeNode.get_content_box(box);
+        const labelHeight = this._label.height;
+        const totalLabelHeight =
+            labelHeight + themeNode.get_padding(St.Side.BOTTOM);
+
+        box.y2 -= totalLabelHeight;
+        super.vfunc_allocate(box);
+
+        // Hooking up the parent vfunc will call this.set_allocation() with
+        // the height without the label height, so call it again with the
+        // correct size here.
+        box.y2 += totalLabelHeight;
+        this.set_allocation(box);
+
+        const childBox = new Clutter.ActorBox();
+        childBox.x1 = contentBox.x1;
+        childBox.x2 = contentBox.x2;
+        childBox.y2 = contentBox.y2;
+        childBox.y1 = childBox.y2 - labelHeight;
+        this._label.allocate(childBox);
+    }
+
+    highlight(index, justOutline) {
+        super.highlight(index, justOutline);
+
+        this._label.set_text(index == -1 ? '' : this.icons[index].label.text);
+    }
+
+    _removeWindow(window) {
+        let index = this.icons.findIndex(icon => {
+            return icon.window == window;
+        });
+        if (index === -1)
+            return;
+
+        this.icons.splice(index, 1);
+        this.removeItem(index);
+    }
+});