quickSettings: Introduce QuickSettingsMenu

The quick settings menu is a popover that arranges items in a
reflowing, homogeneous grid. Grid children may span multiple
columns, but not rows.

For now the QuickSettingsMenu that contains the grid is just a
convenience wrapper around the layout manager that does the heavy
lifting. The two will become more intertwined when we add support
for menu toggles though, so the custom menu type is unfortunately
needed.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2392>

data/theme/gnome-shell-sass/_widgets.scss

@@ -33,6 +33,7 @@
 // Panel
 @import 'widgets/panel';
 @import 'widgets/corner-ripple';
+@import 'widgets/quick-settings';
 // Overview
 @import 'widgets/overview';
 @import 'widgets/window-picker';

data/theme/gnome-shell-sass/widgets/_quick-settings.scss

@@ -0,0 +1,8 @@
+.quick-settings {
+  padding: 4 * $base_padding;
+}
+
+.quick-settings-grid {
+  spacing-rows: 3 * $base_padding;
+  spacing-columns: 2 * $base_padding;
+}

data/theme/meson.build

@@ -29,6 +29,7 @@ theme_sources = files([
   'gnome-shell-sass/widgets/_overview.scss',
   'gnome-shell-sass/widgets/_panel.scss',
   'gnome-shell-sass/widgets/_popovers.scss',
+  'gnome-shell-sass/widgets/_quick-settings.scss',
   'gnome-shell-sass/widgets/_screen-shield.scss',
   'gnome-shell-sass/widgets/_screenshot.scss',
   'gnome-shell-sass/widgets/_scrollbars.scss',

js/js-resources.gresource.xml

@@ -93,6 +93,7 @@
     <file>ui/pointerA11yTimeout.js</file>
     <file>ui/pointerWatcher.js</file>
     <file>ui/popupMenu.js</file>
+    <file>ui/quickSettings.js</file>
     <file>ui/remoteSearch.js</file>
     <file>ui/ripples.js</file>
     <file>ui/runDialog.js</file>

js/ui/quickSettings.js

@@ -0,0 +1,207 @@
+/* exported QuickSettingsMenu */
+const {Clutter, GLib, GObject, St} = imports.gi;
+
+const Main = imports.ui.main;
+const PopupMenu = imports.ui.popupMenu;
+
+const QuickSettingsLayoutMeta = GObject.registerClass({
+    Properties: {
+        'column-span': GObject.ParamSpec.int(
+            'column-span', '', '',
+            GObject.ParamFlags.READWRITE,
+            1, GLib.MAXINT32, 1),
+    },
+}, class QuickSettingsLayoutMeta extends Clutter.LayoutMeta {});
+
+const QuickSettingsLayout = GObject.registerClass({
+    Properties: {
+        'row-spacing': GObject.ParamSpec.int(
+            'row-spacing', 'row-spacing', 'row-spacing',
+            GObject.ParamFlags.READWRITE,
+            0, GLib.MAXINT32, 0),
+        'column-spacing': GObject.ParamSpec.int(
+            'column-spacing', 'column-spacing', 'column-spacing',
+            GObject.ParamFlags.READWRITE,
+            0, GLib.MAXINT32, 0),
+        'n-columns': GObject.ParamSpec.int(
+            'n-columns', 'n-columns', 'n-columns',
+            GObject.ParamFlags.READWRITE,
+            1, GLib.MAXINT32, 1),
+    },
+}, class QuickSettingsLayout extends Clutter.LayoutManager {
+    _containerStyleChanged() {
+        const node = this._container.get_theme_node();
+
+        let changed = false;
+        let found, length;
+        [found, length] = node.lookup_length('spacing-rows', false);
+        changed ||= found;
+        if (found)
+            this.rowSpacing = length;
+
+        [found, length] = node.lookup_length('spacing-columns', false);
+        changed ||= found;
+        if (found)
+            this.columnSpacing = length;
+
+        if (changed)
+            this.layout_changed();
+    }
+
+    _getColSpan(container, child) {
+        const {columnSpan} = this.get_child_meta(container, child);
+        return Math.clamp(columnSpan, 1, this.nColumns);
+    }
+
+    _getMaxChildWidth(container) {
+        let [minWidth, natWidth] = [0, 0];
+
+        for (const child of container) {
+            const [childMin, childNat] = child.get_preferred_width(-1);
+            const colSpan = this._getColSpan(container, child);
+            minWidth = Math.max(minWidth, childMin / colSpan);
+            natWidth = Math.max(natWidth, childNat / colSpan);
+        }
+
+        return [minWidth, natWidth];
+    }
+
+    _getRows(container) {
+        const rows = [];
+        let lineIndex = 0;
+        let curRow;
+
+        /** private */
+        function appendRow() {
+            curRow = [];
+            rows.push(curRow);
+            lineIndex = 0;
+        }
+
+        for (const child of container) {
+            if (!child.visible)
+                continue;
+
+            if (lineIndex === 0)
+                appendRow();
+
+            const colSpan = this._getColSpan(container, child);
+            const fitsRow = lineIndex + colSpan <= this.nColumns;
+
+            if (!fitsRow)
+                appendRow();
+
+            curRow.push(child);
+            lineIndex = (lineIndex + colSpan) % this.nColumns;
+        }
+
+        return rows;
+    }
+
+    _getRowHeight(children) {
+        let [minHeight, natHeight] = [0, 0];
+
+        children.forEach(child => {
+            const [childMin, childNat] = child.get_preferred_height(-1);
+            minHeight = Math.max(minHeight, childMin);
+            natHeight = Math.max(natHeight, childNat);
+        });
+
+        return [minHeight, natHeight];
+    }
+
+    vfunc_get_child_meta_type() {
+        return QuickSettingsLayoutMeta.$gtype;
+    }
+
+    vfunc_set_container(container) {
+        this._container?.disconnectObject(this);
+
+        this._container = container;
+
+        this._container?.connectObject('style-changed',
+            () => this._containerStyleChanged(), this);
+    }
+
+    vfunc_get_preferred_width(container, _forHeight) {
+        const [childMin, childNat] = this._getMaxChildWidth(container);
+        const spacing = (this.nColumns - 1) * this.column_spacing;
+        return [this.nColumns * childMin + spacing, this.nColumns * childNat + spacing];
+    }
+
+    vfunc_get_preferred_height(container, _forWidth) {
+        const rows = this._getRows(container);
+
+        let [minHeight, natHeight] = [0, 0];
+
+        const spacing = (rows.length - 1) * this.row_spacing;
+        minHeight += spacing;
+        natHeight += spacing;
+
+        rows.forEach(row => {
+            const [rowMin, rowNat] = this._getRowHeight(row);
+            minHeight += rowMin;
+            natHeight += rowNat;
+        });
+
+        return [minHeight, natHeight];
+    }
+
+    vfunc_allocate(container, box) {
+        const rows = this._getRows(container);
+
+        const availWidth = box.get_width() - (this.nColumns - 1) * this.row_spacing;
+        const childWidth = availWidth / this.nColumns;
+
+        const isRtl = container.text_direction === Clutter.TextDirection.RTL;
+
+        const childBox = new Clutter.ActorBox();
+        let y = box.y1;
+        rows.forEach(row => {
+            const [, rowNat] = this._getRowHeight(row);
+
+            let lineIndex = 0;
+            row.forEach(child => {
+                const colSpan = this._getColSpan(container, child);
+                const width =
+                    childWidth * colSpan + this.column_spacing * (colSpan - 1);
+                let x = box.x1 + lineIndex * (childWidth + this.column_spacing);
+                if (isRtl)
+                    x = box.x2 - width - x;
+
+                childBox.set_origin(x, y);
+                childBox.set_size(width, rowNat);
+                child.allocate(childBox);
+
+                lineIndex = (lineIndex + colSpan) % this.nColumns;
+            });
+
+            y += rowNat + this.row_spacing;
+        });
+    }
+});
+
+var QuickSettingsMenu = class extends PopupMenu.PopupMenu {
+    constructor(sourceActor, nColumns = 1) {
+        super(sourceActor, 0, St.Side.TOP);
+
+        Main.layoutManager.connectObject('system-modal-opened',
+            () => this.close(), this);
+
+        this.box.add_style_class_name('quick-settings');
+
+        this._grid = new St.Widget({
+            style_class: 'quick-settings-grid',
+            layout_manager: new QuickSettingsLayout({
+                nColumns,
+            }),
+        });
+        this.box.add_child(this._grid);
+    }
+
+    addItem(item, colSpan = 1) {
+        this._grid.add_child(item);
+        this._grid.layout_manager.child_set_property(
+            this._grid, item, 'column-span', colSpan);
+    }
+};