Rename start and end edge into leading and trailing

Author: Kamil Klyta

README.md

@@ -147,11 +147,11 @@ The default value equals `0.1(6)`.
 
 ### trigger (IndicatorTrigger)
 Defines the trigger for the pull to refresh gesture.
-| value         | Description                                                                                                                                                                |
-| ------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| **startEdge** | Pull to refresh can be triggered only from the **start** edge of the list. Mostly top side, but can be bottom for reversed ListView (with *reverse* argument set to true). |
-| **endEdge**   | Pull to refresh can be triggered only from the **end** edge of the list. Mostly bottom, but can be top for reversed ListView (with *reverse* argument set to true).        |
-| **bothEdges** | Pull to refresh can be triggered from **both edges** of the list.                                                                                                          |
+| value            | Description                                                                                                                                                                  |
+| ---------------- | :--------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| **leadingEdge**  | Pull to refresh can be triggered only from the **leading** edge of the list. Mostly top side, but can be bottom for reversed ListView (with *reverse* argument set to true). |
+| **trailingEdge** | Pull to refresh can be triggered only from the **trailing** edge of the list. Mostly bottom, but can be top for reversed ListView (with *reverse* argument set to true).     |
+| **bothEdges**    | Pull to refresh can be triggered from **both edges** of the list.                                                                                                            |
 
 ### triggerMode (IndicatorTriggerMode)
 Configures how *CustomRefreshIndicator* widget can be triggered. Works in the same way as the triggerMode of the built-in *RefreshIndicator* widget.
@@ -177,7 +177,7 @@ Open the sample application and try it yourself ([online example](https://custom
 
 [![Controller data example](readme/controller_data.gif)](https://custom-refresh-indicator.klyta.it/#/presentation)  
 
-### state
+### state (IndicatorState)
 The following table describes each state of the indicator controller.
 
 | value          | Description                                                                                                                                                                                                                        |

example/lib/indicators/swipe_action.dart

@@ -17,7 +17,7 @@ class FetchMoreIndicator extends StatelessWidget {
     const height = 150.0;
     return CustomRefreshIndicator(
       onRefresh: () async => onAction(),
-      trigger: IndicatorTrigger.endEdge,
+      trigger: IndicatorTrigger.trailingEdge,
       trailingScrollIndicatorVisible: false,
       leadingScrollIndicatorVisible: true,
       child: child,

lib/src/controller.dart

@@ -87,13 +87,13 @@ class IndicatorController extends ChangeNotifier {
     if (edge == null) return IndicatorSide.none;
     switch (direction) {
       case AxisDirection.up:
-        return edge.isStart ? IndicatorSide.bottom : IndicatorSide.top;
+        return edge.isLeading ? IndicatorSide.bottom : IndicatorSide.top;
       case AxisDirection.right:
-        return edge.isStart ? IndicatorSide.left : IndicatorSide.right;
+        return edge.isLeading ? IndicatorSide.left : IndicatorSide.right;
       case AxisDirection.down:
-        return edge.isStart ? IndicatorSide.top : IndicatorSide.bottom;
+        return edge.isLeading ? IndicatorSide.top : IndicatorSide.bottom;
       case AxisDirection.left:
-        return edge.isStart ? IndicatorSide.right : IndicatorSide.left;
+        return edge.isLeading ? IndicatorSide.right : IndicatorSide.left;
     }
   }
 

lib/src/custom_refresh_indicator.dart

@@ -16,10 +16,10 @@ typedef OnStateChanged = void Function(IndicatorStateChange change);
 extension on IndicatorTrigger {
   IndicatorEdge? get derivedEdge {
     switch (this) {
-      case IndicatorTrigger.startEdge:
-        return IndicatorEdge.start;
-      case IndicatorTrigger.endEdge:
-        return IndicatorEdge.end;
+      case IndicatorTrigger.leadingEdge:
+        return IndicatorEdge.leading;
+      case IndicatorTrigger.trailingEdge:
+        return IndicatorEdge.trailing;
 
       /// In this case, the side is determined by the direction of the user's
       /// first scrolling gesture, not the trigger itself.
@@ -148,7 +148,7 @@ class CustomRefreshIndicator extends StatefulWidget {
     required this.onRefresh,
     required this.builder,
     this.controller,
-    this.trigger = IndicatorTrigger.startEdge,
+    this.trigger = IndicatorTrigger.leadingEdge,
     this.triggerMode = IndicatorTriggerMode.onEdge,
     this.notificationPredicate = defaultScrollNotificationPredicate,
     this.autoRebuild = true,
@@ -253,9 +253,9 @@ class CustomRefreshIndicatorState extends State<CustomRefreshIndicator>
     IndicatorTrigger trigger,
   ) {
     switch (trigger) {
-      case IndicatorTrigger.startEdge:
+      case IndicatorTrigger.leadingEdge:
         return notification.metrics.extentBefore == 0;
-      case IndicatorTrigger.endEdge:
+      case IndicatorTrigger.trailingEdge:
         return notification.metrics.extentAfter == 0;
       case IndicatorTrigger.bothEdges:
         return notification.metrics.extentBefore == 0 ||
@@ -295,12 +295,12 @@ class CustomRefreshIndicatorState extends State<CustomRefreshIndicator>
       if (notification.metrics.extentBefore == 0 &&
           notification.scrollDelta!.isNegative) {
         controller
-          ..setIndicatorEdge(IndicatorEdge.start)
+          ..setIndicatorEdge(IndicatorEdge.leading)
           ..setIndicatorState(IndicatorState.dragging);
       } else if (notification.metrics.extentAfter == 0 &&
           !notification.scrollDelta!.isNegative) {
         controller
-          ..setIndicatorEdge(IndicatorEdge.end)
+          ..setIndicatorEdge(IndicatorEdge.trailing)
           ..setIndicatorState(IndicatorState.dragging);
       }
     }
@@ -313,7 +313,7 @@ class CustomRefreshIndicatorState extends State<CustomRefreshIndicator>
       /// Handle the indicator state depending on scrolling direction
     } else if (controller.state.isDragging || controller.state.isArmed) {
       switch (controller.edge) {
-        case IndicatorEdge.start:
+        case IndicatorEdge.leading:
           if (notification.metrics.extentBefore > 0.0) {
             _hide();
           } else {
@@ -323,7 +323,7 @@ class CustomRefreshIndicatorState extends State<CustomRefreshIndicator>
           }
           break;
 
-        case IndicatorEdge.end:
+        case IndicatorEdge.trailing:
           if (notification.metrics.extentAfter > 0.0) {
             _hide();
           } else {
@@ -347,12 +347,12 @@ class CustomRefreshIndicatorState extends State<CustomRefreshIndicator>
     if (!controller.hasEdge) {
       controller.setIndicatorEdge(
         notification.overscroll.isNegative
-            ? IndicatorEdge.start
-            : IndicatorEdge.end,
+            ? IndicatorEdge.leading
+            : IndicatorEdge.trailing,
       );
     }
 
-    if (controller.edge!.isStart) {
+    if (controller.edge!.isLeading) {
       _dragOffset -= notification.overscroll;
     } else {
       _dragOffset += notification.overscroll;

lib/src/data/indicator_edge.dart

@@ -1,9 +1,9 @@
 enum IndicatorEdge {
-  start,
-  end,
+  leading,
+  trailing,
 }
 
 extension IndicatorEdgeGetters on IndicatorEdge {
-  bool get isEnd => this == IndicatorEdge.end;
-  bool get isStart => this == IndicatorEdge.start;
+  bool get isTrailing => this == IndicatorEdge.trailing;
+  bool get isLeading => this == IndicatorEdge.leading;
 }

lib/src/data/indicator_trigger_edge.dart

@@ -3,27 +3,27 @@
 /// {@endtemplate}
 ///
 /// **startEdge**:
-/// {@macro custom_refresh_indicator.indicator_trigger.start}
+/// {@macro custom_refresh_indicator.indicator_trigger.leading}
 ///
 /// **endEdge**:
-/// {@macro custom_refresh_indicator.indicator_trigger.end}
+/// {@macro custom_refresh_indicator.indicator_trigger.trailing}
 ///
 /// **bothEdges**:
 /// {@macro custom_refresh_indicator.indicator_trigger.both}
 enum IndicatorTrigger {
-  /// {@template custom_refresh_indicator.indicator_trigger.start}
-  /// Pull to refresh can be triggered only from the **start** edge of the list.
+  /// {@template custom_refresh_indicator.indicator_trigger.leading}
+  /// Pull to refresh can be triggered only from the **leading** edge of the list.
   /// Mostly top side, but can be bottom for reversed ListView
   /// (with *reverse* argument set to true).
   /// {@endtemplate}
-  startEdge,
+  leadingEdge,
 
-  /// {@template custom_refresh_indicator.indicator_trigger.end}
-  /// Pull to refresh can be triggered only from the **end** edge of the list.
+  /// {@template custom_refresh_indicator.indicator_trigger.trailing}
+  /// Pull to refresh can be triggered only from the **trailing** edge of the list.
   /// Mostly bottom, but can be top for reversed ListView
   /// (with *reverse* argument set to true).
   /// {@endtemplate}
-  endEdge,
+  trailingEdge,
 
   /// {@template custom_refresh_indicator.indicator_trigger.both}
   /// Pull to refresh can be triggered from **both edges** of the list.

test/src/controller_test.dart

@@ -189,61 +189,61 @@ void main() {
   });
 
   group('IndicatorSide -', () {
-    test('AxisDirection.up - start edge', () {
+    test('AxisDirection.up - leading edge', () {
       final controller = IndicatorController()
         ..setAxisDirection(AxisDirection.up)
-        ..setIndicatorEdge(IndicatorEdge.start);
+        ..setIndicatorEdge(IndicatorEdge.leading);
 
       expect(controller.side, IndicatorSide.bottom);
     });
-    test('AxisDirection.up - end edge', () {
+    test('AxisDirection.up - trailing edge', () {
       final controller = IndicatorController()
         ..setAxisDirection(AxisDirection.up)
-        ..setIndicatorEdge(IndicatorEdge.end);
+        ..setIndicatorEdge(IndicatorEdge.trailing);
 
       expect(controller.side, IndicatorSide.top);
     });
 
-    test('AxisDirection.down - start edge', () {
+    test('AxisDirection.down - leading edge', () {
       final controller = IndicatorController()
         ..setAxisDirection(AxisDirection.down)
-        ..setIndicatorEdge(IndicatorEdge.start);
+        ..setIndicatorEdge(IndicatorEdge.leading);
 
       expect(controller.side, IndicatorSide.top);
     });
-    test('AxisDirection.down - end edge', () {
+    test('AxisDirection.down - trailing edge', () {
       final controller = IndicatorController()
         ..setAxisDirection(AxisDirection.down)
-        ..setIndicatorEdge(IndicatorEdge.end);
+        ..setIndicatorEdge(IndicatorEdge.trailing);
 
       expect(controller.side, IndicatorSide.bottom);
     });
 
-    test('AxisDirection.left - start edge', () {
+    test('AxisDirection.left - leading edge', () {
       final controller = IndicatorController()
         ..setAxisDirection(AxisDirection.left)
-        ..setIndicatorEdge(IndicatorEdge.start);
+        ..setIndicatorEdge(IndicatorEdge.leading);
 
       expect(controller.side, IndicatorSide.right);
     });
-    test('AxisDirection.left - end edge', () {
+    test('AxisDirection.left - trailing edge', () {
       final controller = IndicatorController()
         ..setAxisDirection(AxisDirection.left)
-        ..setIndicatorEdge(IndicatorEdge.end);
+        ..setIndicatorEdge(IndicatorEdge.trailing);
 
       expect(controller.side, IndicatorSide.left);
     });
-    test('AxisDirection.right - start edge', () {
+    test('AxisDirection.right - leading edge', () {
       final controller = IndicatorController()
         ..setAxisDirection(AxisDirection.right)
-        ..setIndicatorEdge(IndicatorEdge.start);
+        ..setIndicatorEdge(IndicatorEdge.leading);
 
       expect(controller.side, IndicatorSide.left);
     });
-    test('AxisDirection.right - end edge', () {
+    test('AxisDirection.right - trailing edge', () {
       final controller = IndicatorController()
         ..setAxisDirection(AxisDirection.right)
-        ..setIndicatorEdge(IndicatorEdge.end);
+        ..setIndicatorEdge(IndicatorEdge.trailing);
 
       expect(controller.side, IndicatorSide.right);
     });

test/src/custom_refresh_indicator_test.dart

@@ -205,7 +205,7 @@ void main() {
     expect(controller.value, equals(1.0));
     expect(controller.state, equals(IndicatorState.loading));
     expect(controller.hasEdge, isTrue);
-    expect(controller.edge, IndicatorEdge.start);
+    expect(controller.edge, IndicatorEdge.leading);
     expect(controller.side, IndicatorSide.top);
     expect(controller.direction, AxisDirection.down);
     expect(controller.scrollingDirection, ScrollDirection.forward);
@@ -235,7 +235,7 @@ void main() {
     expect(controller.value, equals(1.0));
     expect(controller.state, equals(IndicatorState.loading));
     expect(controller.hasEdge, isTrue);
-    expect(controller.edge, IndicatorEdge.start);
+    expect(controller.edge, IndicatorEdge.leading);
     expect(controller.side, IndicatorSide.bottom);
     expect(controller.direction, AxisDirection.up);
     expect(controller.scrollingDirection, ScrollDirection.forward);
@@ -885,7 +885,7 @@ void main() {
 
     expect(indicatorController.value, greaterThan(0.0));
     expect(indicatorController.value, lessThanOrEqualTo(1.0));
-    expect(indicatorController.edge, IndicatorEdge.start);
+    expect(indicatorController.edge, IndicatorEdge.leading);
     expect(fakeRefresh.called, isTrue);
     // finish the indicator
     await tester.pump(const Duration(seconds: 1));
@@ -906,7 +906,7 @@ void main() {
 
     expect(indicatorController.value, greaterThan(0.0));
     expect(indicatorController.value, lessThanOrEqualTo(1.0));
-    expect(indicatorController.edge, IndicatorEdge.end);
+    expect(indicatorController.edge, IndicatorEdge.trailing);
     expect(fakeRefresh.called, isTrue);
 
     // finish the indicator
@@ -924,7 +924,7 @@ void main() {
         home: CustomRefreshIndicator(
           controller: indicatorController,
           builder: buildWithoutIndicator,
-          trigger: IndicatorTrigger.endEdge,
+          trigger: IndicatorTrigger.trailingEdge,
           onRefresh: fakeRefresh.instantRefresh,
           child: const DefaultList(itemsCount: 1),
         ),
@@ -945,7 +945,7 @@ void main() {
 
     expect(indicatorController.value, greaterThan(0.0));
     expect(indicatorController.value, lessThanOrEqualTo(1.0));
-    expect(indicatorController.edge, IndicatorEdge.end);
+    expect(indicatorController.edge, IndicatorEdge.trailing);
     expect(fakeRefresh.called, isTrue);
 
     // finish the indicator
@@ -963,7 +963,7 @@ void main() {
         home: CustomRefreshIndicator(
           controller: indicatorController,
           builder: buildWithoutIndicator,
-          trigger: IndicatorTrigger.startEdge,
+          trigger: IndicatorTrigger.leadingEdge,
           onRefresh: fakeRefresh.instantRefresh,
           child: const DefaultList(itemsCount: 1),
         ),
@@ -984,7 +984,7 @@ void main() {
 
     expect(indicatorController.value, greaterThan(0.0));
     expect(indicatorController.value, lessThanOrEqualTo(1.0));
-    expect(indicatorController.edge, IndicatorEdge.start);
+    expect(indicatorController.edge, IndicatorEdge.leading);
     expect(fakeRefresh.called, isTrue);
     // finish the indicator
     await tester.pump(const Duration(seconds: 1));

test/src/data/indicator_edge_test.dart

@@ -2,15 +2,15 @@ import 'package:custom_refresh_indicator/src/data/indicator_edge.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {
-  test('IndicatorEdgeGetters - end', () async {
-    const end = IndicatorEdge.end;
-    expect(end.isStart, isFalse);
-    expect(end.isEnd, isTrue);
+  test('IndicatorEdgeGetters - trailing', () async {
+    const end = IndicatorEdge.trailing;
+    expect(end.isLeading, isFalse);
+    expect(end.isTrailing, isTrue);
   });
 
-  test('IndicatorEdgeGetters - start', () async {
-    const start = IndicatorEdge.start;
-    expect(start.isStart, isTrue);
-    expect(start.isEnd, isFalse);
+  test('IndicatorEdgeGetters - leading', () async {
+    const start = IndicatorEdge.leading;
+    expect(start.isLeading, isTrue);
+    expect(start.isTrailing, isFalse);
   });
 }