feat(deriv_ui): [DERG 2450] Added Timeline Widget to Deriv UI

packages/deriv_ui/lib/components/timeline/src/connector_theme.dart

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+import 'dart:ui' show lerpDouble;
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/widgets.dart';
+import 'connectors.dart';
+import 'timeline_node.dart';
+import 'timeline_theme.dart';
+
+/// Defines the visual properties of [SolidLineConnector], connectors inside
+/// [TimelineNode].
+///
+/// Descendant widgets obtain the current [ConnectorThemeData] object using
+/// `ConnectorTheme.of(context)`. Instances of [ConnectorThemeData] can be
+/// customized with [ConnectorThemeData.copyWith].
+///
+/// Typically a [ConnectorThemeData] is specified as part of the overall
+/// [TimelineTheme] with [TimelineThemeData.connectorTheme].
+///
+/// All [ConnectorThemeData] properties are `null` by default. When null, the
+/// widgets will provide their own defaults.
+///
+/// See also:
+///
+///  * [TimelineThemeData], which describes the overall theme information for
+///  the timeline.
+@immutable
+class ConnectorThemeData with Diagnosticable {
+  /// Creates a theme that can be used for [ConnectorTheme] or
+  /// [TimelineThemeData.connectorTheme].
+  const ConnectorThemeData({
+    this.color,
+    this.space,
+    this.thickness,
+    this.indent,
+  });
+
+  /// The color of [SolidLineConnector]s and connectors inside [TimelineNode]s,
+  /// and so forth.
+  final Color? color;
+
+  /// This represents the amount of horizontal or vertical space the connector
+  /// takes up.
+  final double? space;
+
+  /// The thickness of the line drawn within the connector.
+  final double? thickness;
+
+  /// The amount of empty space at the edge of [SolidLineConnector].
+  final double? indent;
+
+  /// Creates a copy of this object with the given fields replaced with the new
+  /// values.
+  ConnectorThemeData copyWith({
+    Color? color,
+    double? space,
+    double? thickness,
+    double? indent,
+  }) =>
+      ConnectorThemeData(
+        color: color ?? this.color,
+        space: space ?? this.space,
+        thickness: thickness ?? this.thickness,
+        indent: indent ?? this.indent,
+      );
+
+  /// Linearly interpolate between two Connector themes.
+  ///
+  /// The argument `t` must not be null.
+  ///
+  /// {@macro dart.ui.shadow.lerp}
+  static ConnectorThemeData lerp(
+          ConnectorThemeData? a, ConnectorThemeData? b, double t) =>
+      ConnectorThemeData(
+        color: Color.lerp(a?.color, b?.color, t),
+        space: lerpDouble(a?.space, b?.space, t),
+        thickness: lerpDouble(a?.thickness, b?.thickness, t),
+        indent: lerpDouble(a?.indent, b?.indent, t),
+      );
+
+  @override
+  int get hashCode => Object.hash(
+        color,
+        space,
+        thickness,
+        indent,
+      );
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) {
+      return true;
+    }
+    if (other.runtimeType != runtimeType) {
+      return false;
+    }
+    return other is ConnectorThemeData &&
+        other.color == color &&
+        other.space == space &&
+        other.thickness == thickness &&
+        other.indent == indent;
+  }
+
+  @override
+  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
+    super.debugFillProperties(properties);
+    properties
+      ..add(ColorProperty('color', color, defaultValue: null))
+      ..add(DoubleProperty('space', space, defaultValue: null))
+      ..add(DoubleProperty('thickness', thickness, defaultValue: null))
+      ..add(DoubleProperty('indent', indent, defaultValue: null));
+  }
+}
+
+/// An inherited widget that defines the configuration for
+/// [SolidLineConnector]s, connectors inside [TimelineNode]s.
+class ConnectorTheme extends InheritedTheme {
+  /// Creates a connector theme that controls the configurations for
+  /// [SolidLineConnector]s, connectors inside [TimelineNode]s.
+  const ConnectorTheme({
+    required this.data,
+    required Widget child,
+    Key? key,
+  }) : super(key: key, child: child);
+
+  /// The properties for descendant [SolidLineConnector]s, connectors inside
+  /// [TimelineNode]s.
+  final ConnectorThemeData data;
+
+  /// The closest instance of this class's [data] value that encloses the given
+  /// context.
+  ///
+  /// If there is no ancestor, it returns [TimelineThemeData.connectorTheme].
+  /// Applications can assume that the returned value will not be null.
+  ///
+  /// Typical usage is as follows:
+  ///
+  /// ```dart
+  /// ConnectorThemeData theme = ConnectorTheme.of(context);
+  /// ```
+  static ConnectorThemeData of(BuildContext context) {
+    final ConnectorTheme? connectorTheme =
+        context.dependOnInheritedWidgetOfExactType<ConnectorTheme>();
+    return connectorTheme?.data ?? TimelineTheme.of(context).connectorTheme;
+  }
+
+  @override
+  Widget wrap(BuildContext context, Widget child) {
+    final ConnectorTheme? ancestorTheme =
+        context.findAncestorWidgetOfExactType<ConnectorTheme>();
+    return identical(this, ancestorTheme)
+        ? child
+        : ConnectorTheme(data: data, child: child);
+  }
+
+  @override
+  bool updateShouldNotify(ConnectorTheme oldWidget) => data != oldWidget.data;
+
+  @override
+  void debugFillProperties(DiagnosticPropertiesBuilder properties) {
+    super.debugFillProperties(properties);
+    data.debugFillProperties(properties);
+  }
+}
+
+/// Connector component configured through [ConnectorTheme]
+mixin ThemedConnectorComponent on Widget {
+  /// {@template timelines.connector.direction}
+  /// If this is null, then the [TimelineThemeData.direction] is used.
+  /// {@endtemplate}
+  Axis? get direction;
+  Axis getEffectiveDirection(BuildContext context) =>
+      direction ?? TimelineTheme.of(context).direction;
+
+  /// {@template timelines.connector.thickness}
+  /// If this is null, then the [ConnectorThemeData.thickness] is used which
+  /// defaults to 2.0.
+  /// {@endtemplate}
+  double? get thickness;
+  double getEffectiveThickness(BuildContext context) =>
+      thickness ?? ConnectorTheme.of(context).thickness ?? 2.0;
+
+  /// {@template timelines.connector.space}
+  /// If this is null, then the [ConnectorThemeData.space] is used. If that is
+  /// also null, then this defaults to double.infinity.
+  /// {@endtemplate}
+  double? get space;
+  double? getEffectiveSpace(BuildContext context) =>
+      space ?? ConnectorTheme.of(context).space;
+
+  double? get indent;
+  double getEffectiveIndent(BuildContext context) =>
+      indent ?? ConnectorTheme.of(context).indent ?? 0.0;
+
+  double? get endIndent;
+  double getEffectiveEndIndent(BuildContext context) =>
+      endIndent ?? ConnectorTheme.of(context).indent ?? 0.0;
+
+  Color? get color;
+  Color getEffectiveColor(BuildContext context) =>
+      color ??
+      ConnectorTheme.of(context).color ??
+      TimelineTheme.of(context).color;
+}