Initial commit

lib/src/tree_view.dart

@@ -0,0 +1,142 @@
+import 'package:flutter/material.dart';
+
+import 'tree_view_controller.dart';
+import 'tree_view_theme.dart';
+import 'tree_node.dart';
+import 'models/node.dart';
+
+/// Defines the [TreeView] widget.
+///
+/// This is the main widget for the package. It requires a controller
+/// and allows you to specify other optional properties that manages
+/// the appearance and handle events.
+///
+/// ```dart
+/// TreeView(
+///   controller: _treeViewController,
+///   allowParentSelect: false,
+///   supportParentDoubleTap: false,
+///   onExpansionChanged: _expandNodeHandler,
+///   onNodeTap: (key) {
+///     setState(() {
+///       _treeViewController = _treeViewController.copyWith(selectedKey: key);
+///     });
+///   },
+///   theme: treeViewTheme
+/// ),
+/// ```
+class TreeView extends InheritedWidget {
+  /// The controller for the [TreeView]. It manages the data and selected key.
+  final TreeViewController controller;
+
+  /// The tap handler for a node. Passes the node key.
+  final Function(String)? onNodeTap;
+
+  /// Custom builder for nodes. Parameters are the build context and tree node.
+  final Widget Function(BuildContext, Node)? nodeBuilder;
+
+  /// The double tap handler for a node. Passes the node key.
+  final Function(String)? onNodeDoubleTap;
+
+  /// The expand/collapse handler for a node. Passes the node key and the
+  /// expansion state.
+  final Function(String, bool)? onExpansionChanged;
+
+  /// The theme for [TreeView].
+  final TreeViewTheme theme;
+
+  /// Determines whether the user can select a parent node. If false,
+  /// tapping the parent will expand or collapse the node. If true, the node
+  /// will be selected and the use has to use the expander to expand or
+  /// collapse the node.
+  final bool allowParentSelect;
+
+  /// How the [TreeView] should respond to user input.
+  final ScrollPhysics? physics;
+
+  /// Whether the extent of the [TreeView] should be determined by the contents
+  /// being viewed.
+  ///
+  /// Defaults to false.
+  final bool shrinkWrap;
+
+  /// Whether the [TreeView] is the primary scroll widget associated with the
+  /// parent PrimaryScrollController..
+  ///
+  /// Defaults to true.
+  final bool primary;
+
+  /// Determines whether the parent node can receive a double tap. This is
+  /// useful if [allowParentSelect] is true. This allows the user to double tap
+  /// the parent node to expand or collapse the parent when [allowParentSelect]
+  /// is true.
+  /// ___IMPORTANT___
+  /// _When true, the tap handler is delayed. This is because the double tap
+  /// action requires a short delay to determine whether the user is attempting
+  /// a single or double tap._
+  final bool supportParentDoubleTap;
+
+  TreeView({
+    Key? key,
+    required this.controller,
+    this.onNodeTap,
+    this.onNodeDoubleTap,
+    this.physics,
+    this.onExpansionChanged,
+    this.allowParentSelect: false,
+    this.supportParentDoubleTap: false,
+    this.shrinkWrap: false,
+    this.primary: true,
+    this.nodeBuilder,
+    TreeViewTheme? theme,
+  })  : this.theme = theme ?? const TreeViewTheme(),
+        super(
+          key: key,
+          child: _TreeViewData(
+            controller,
+            shrinkWrap: shrinkWrap,
+            primary: primary,
+            physics: physics,
+          ),
+        );
+
+  static TreeView? of(BuildContext context) =>
+      context.dependOnInheritedWidgetOfExactType(aspect: TreeView);
+
+  @override
+  bool updateShouldNotify(TreeView oldWidget) {
+    return oldWidget.controller.children != this.controller.children ||
+        oldWidget.onNodeTap != this.onNodeTap ||
+        oldWidget.onExpansionChanged != this.onExpansionChanged ||
+        oldWidget.theme != this.theme ||
+        oldWidget.supportParentDoubleTap != this.supportParentDoubleTap ||
+        oldWidget.allowParentSelect != this.allowParentSelect;
+  }
+}
+
+class _TreeViewData extends StatelessWidget {
+  final TreeViewController _controller;
+  final bool? shrinkWrap;
+  final bool? primary;
+  final ScrollPhysics? physics;
+
+  const _TreeViewData(this._controller,
+      {this.shrinkWrap, this.primary, this.physics});
+
+  @override
+  Widget build(BuildContext context) {
+    ThemeData _parentTheme = Theme.of(context);
+    return Theme(
+      data: _parentTheme.copyWith(hoverColor: Colors.grey.shade100),
+      child: ListView(
+        shrinkWrap: shrinkWrap!,
+        primary: primary,
+        physics: physics,
+        padding: EdgeInsets.zero,
+        children: _controller.children.map((Node node) {
+          return TreeNode(node: node);
+        }).toList(),
+      ),
+    );
+  }
+}