Add pageStep (#56)

Author: jpnurmi

lib/src/base_spin_box.dart

@@ -33,6 +33,7 @@ abstract class BaseSpinBox extends StatefulWidget {
   double get min;
   double get max;
   double get step;
+  double get pageStep;
   double get value;
   int get decimals;
   int get digits;
@@ -66,8 +67,10 @@ mixin SpinBoxMixin<T extends BaseSpinBox> on State<T> {
     return {
       // ### TODO: use SingleActivator fixed in Flutter 2.10+
       // https://github.com/flutter/flutter/issues/92717
-      LogicalKeySet(LogicalKeyboardKey.arrowUp): _increaseValue,
-      LogicalKeySet(LogicalKeyboardKey.arrowDown): _decreaseValue,
+      LogicalKeySet(LogicalKeyboardKey.arrowUp): _stepUp,
+      LogicalKeySet(LogicalKeyboardKey.arrowDown): _stepDown,
+      LogicalKeySet(LogicalKeyboardKey.pageUp): _pageStepUp,
+      LogicalKeySet(LogicalKeyboardKey.pageDown): _pageStepDown,
     };
   }
 
@@ -92,8 +95,11 @@ mixin SpinBoxMixin<T extends BaseSpinBox> on State<T> {
     super.dispose();
   }
 
-  void _increaseValue() => setValue(value + widget.step);
-  void _decreaseValue() => setValue(value - widget.step);
+  void _stepUp() => setValue(value + widget.step);
+  void _stepDown() => setValue(value - widget.step);
+
+  void _pageStepUp() => setValue(value + widget.pageStep);
+  void _pageStepDown() => setValue(value - widget.pageStep);
 
   void _updateValue() {
     final v = _parseValue(_controller.text);

lib/src/cupertino/spin_box.dart

@@ -52,6 +52,7 @@ class CupertinoSpinBox extends BaseSpinBox {
     this.min = 0,
     this.max = 100,
     this.step = 1,
+    this.pageStep = 10,
     this.value = 0,
     this.interval = const Duration(milliseconds: 100),
     this.acceleration,
@@ -119,6 +120,12 @@ class CupertinoSpinBox extends BaseSpinBox {
   @override
   final double step;
 
+  /// The page step size for incrementing and decrementing the value.
+  ///
+  /// Defaults to `10.0`.
+  @override
+  final double pageStep;
+
   /// The current value.
   ///
   /// Defaults to `0.0`.

lib/src/material/spin_box.dart

@@ -53,6 +53,7 @@ class SpinBox extends BaseSpinBox {
     this.min = 0,
     this.max = 100,
     this.step = 1,
+    this.pageStep = 10,
     this.value = 0,
     this.interval = const Duration(milliseconds: 100),
     this.acceleration,
@@ -117,6 +118,12 @@ class SpinBox extends BaseSpinBox {
   @override
   final double step;
 
+  /// The page step size for incrementing and decrementing the value.
+  ///
+  /// Defaults to `10.0`.
+  @override
+  final double pageStep;
+
   /// The current value.
   ///
   /// Defaults to `0.0`.

test/test_spinbox.dart

@@ -164,6 +164,42 @@ void testInput<S>(TestBuilder builder) {
       expect(find.editableText, hasText('0'));
     });
 
+    testWidgets('page step', (tester) async {
+      await tester.pumpWidget(builder());
+      expect(find.editableText, hasFocus);
+      await tester.showKeyboard(find.byType(S));
+
+      await tester.sendKeyEvent(LogicalKeyboardKey.pageDown);
+      await tester.idle();
+      expect(tester.state(find.byType(S)), hasValue(0));
+      expect(find.editableText, hasText('0'));
+
+      await tester.sendKeyEvent(LogicalKeyboardKey.pageUp);
+      await tester.idle();
+      expect(tester.state(find.byType(S)), hasValue(10));
+      expect(find.editableText, hasText('10'));
+
+      await tester.sendKeyEvent(LogicalKeyboardKey.pageUp);
+      await tester.idle();
+      expect(tester.state(find.byType(S)), hasValue(20));
+      expect(find.editableText, hasText('20'));
+
+      await tester.sendKeyEvent(LogicalKeyboardKey.arrowDown);
+      await tester.idle();
+      expect(tester.state(find.byType(S)), hasValue(19));
+      expect(find.editableText, hasText('19'));
+
+      await tester.sendKeyEvent(LogicalKeyboardKey.pageDown);
+      await tester.idle();
+      expect(tester.state(find.byType(S)), hasValue(9));
+      expect(find.editableText, hasText('9'));
+
+      await tester.sendKeyEvent(LogicalKeyboardKey.pageDown);
+      await tester.idle();
+      expect(tester.state(find.byType(S)), hasValue(0));
+      expect(find.editableText, hasText('0'));
+    });
+
     testWidgets('text', (tester) async {
       await tester.pumpWidget(builder());
       expect(find.editableText, hasFocus);