v7

lib/go_router/overlay/context_menu/context_menu_controller.0.dart

@@ -0,0 +1,183 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This sample demonstrates allowing a context menu to be shown in a widget
+// subtree in response to user gestures.
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+
+void main() => runApp(const ContextMenuControllerExampleApp());
+
+/// A builder that includes an Offset to draw the context menu at.
+typedef ContextMenuBuilder = Widget Function(BuildContext context, Offset offset);
+
+class ContextMenuControllerExampleApp extends StatefulWidget {
+  const ContextMenuControllerExampleApp({super.key});
+
+  @override
+  State<ContextMenuControllerExampleApp> createState() => _ContextMenuControllerExampleAppState();
+}
+
+class _ContextMenuControllerExampleAppState extends State<ContextMenuControllerExampleApp> {
+  void _showDialog(BuildContext context) {
+    Navigator.of(context).push(
+      DialogRoute<void>(
+        context: context,
+        builder: (BuildContext context) => const AlertDialog(title: Text('You clicked print!')),
+      ),
+    );
+  }
+
+  @override
+  void initState() {
+    super.initState();
+    // On web, disable the browser's context menu since this example uses a custom
+    // Flutter-rendered context menu.
+    if (kIsWeb) {
+      BrowserContextMenu.disableContextMenu();
+    }
+  }
+
+  @override
+  void dispose() {
+    if (kIsWeb) {
+      BrowserContextMenu.enableContextMenu();
+    }
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      home: Scaffold(
+        appBar: AppBar(
+          title: const Text('Context menu outside of text'),
+        ),
+        body: _ContextMenuRegion(
+          contextMenuBuilder: (BuildContext context, Offset offset) {
+            // The custom context menu will look like the default context menu
+            // on the current platform with a single 'Print' button.
+            return AdaptiveTextSelectionToolbar.buttonItems(
+              anchors: TextSelectionToolbarAnchors(
+                primaryAnchor: offset,
+              ),
+              buttonItems: <ContextMenuButtonItem>[
+                ContextMenuButtonItem(
+                  onPressed: () {
+                    ContextMenuController.removeAny();
+                    _showDialog(context);
+                  },
+                  label: 'Print',
+                ),
+              ],
+            );
+          },
+          // In this case this wraps a big open space in a GestureDetector in
+          // order to show the context menu, but it could also wrap a single
+          // widget like an Image to give it a context menu.
+          child: ListView(
+            children: <Widget>[
+              Container(height: 20.0),
+              const Text(
+                  'Right click (desktop) or long press (mobile) anywhere, not just on this text, to show the custom menu.'),
+            ],
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+/// Shows and hides the context menu based on user gestures.
+///
+/// By default, shows the menu on right clicks and long presses.
+class _ContextMenuRegion extends StatefulWidget {
+  /// Creates an instance of [_ContextMenuRegion].
+  const _ContextMenuRegion({
+    required this.child,
+    required this.contextMenuBuilder,
+  });
+
+  /// Builds the context menu.
+  final ContextMenuBuilder contextMenuBuilder;
+
+  /// The child widget that will be listened to for gestures.
+  final Widget child;
+
+  @override
+  State<_ContextMenuRegion> createState() => _ContextMenuRegionState();
+}
+
+class _ContextMenuRegionState extends State<_ContextMenuRegion> {
+  Offset? _longPressOffset;
+
+  final ContextMenuController _contextMenuController = ContextMenuController();
+
+  static bool get _longPressEnabled {
+    switch (defaultTargetPlatform) {
+      case TargetPlatform.android:
+      case TargetPlatform.iOS:
+        return true;
+      case TargetPlatform.macOS:
+      case TargetPlatform.fuchsia:
+      case TargetPlatform.linux:
+      case TargetPlatform.windows:
+        return false;
+    }
+  }
+
+  void _onSecondaryTapUp(TapUpDetails details) {
+    _show(details.globalPosition);
+  }
+
+  void _onTap() {
+    if (!_contextMenuController.isShown) {
+      return;
+    }
+    _hide();
+  }
+
+  void _onLongPressStart(LongPressStartDetails details) {
+    _longPressOffset = details.globalPosition;
+  }
+
+  void _onLongPress() {
+    assert(_longPressOffset != null);
+    _show(_longPressOffset!);
+    _longPressOffset = null;
+  }
+
+  void _show(Offset position) {
+    _contextMenuController.show(
+      context: context,
+      contextMenuBuilder: (BuildContext context) {
+        return widget.contextMenuBuilder(context, position);
+      },
+    );
+  }
+
+  void _hide() {
+    _contextMenuController.remove();
+  }
+
+  @override
+  void dispose() {
+    _hide();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return GestureDetector(
+      behavior: HitTestBehavior.opaque,
+      onSecondaryTapUp: _onSecondaryTapUp,
+      onTap: _onTap,
+      onLongPress: _longPressEnabled ? _onLongPress : null,
+      onLongPressStart: _longPressEnabled ? _onLongPressStart : null,
+      child: widget.child,
+    );
+  }
+}