packages/flutter/lib/src/cupertino/text_selection.dart - mirrors/flutter - Git at Google

 // 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.

 import 'dart:math' as math;

 import 'package:flutter/widgets.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';

 import 'localizations.dart';
 import 'text_selection_toolbar.dart';
 import 'text_selection_toolbar_button.dart';
 import 'theme.dart';

 // Read off from the output on iOS 12. This color does not vary with the
 // application's theme color.
 const double _kSelectionHandleOverlap = 1.5;
 // Extracted from https://developer.apple.com/design/resources/.
 const double _kSelectionHandleRadius = 6;

 // Minimal padding from tip of the selection toolbar arrow to horizontal edges of the
 // screen. Eyeballed value.
 const double _kArrowScreenPadding = 26.0;

 // Generates the child that's passed into CupertinoTextSelectionToolbar.
 class _CupertinoTextSelectionControlsToolbar extends StatefulWidget {
   const _CupertinoTextSelectionControlsToolbar({
     Key? key,
     required this.clipboardStatus,
     required this.endpoints,
     required this.globalEditableRegion,
     required this.handleCopy,
     required this.handleCut,
     required this.handlePaste,
     required this.handleSelectAll,
     required this.selectionMidpoint,
     required this.textLineHeight,
   }) : super(key: key);

   final ClipboardStatusNotifier? clipboardStatus;
   final List<TextSelectionPoint> endpoints;
   final Rect globalEditableRegion;
   final VoidCallback? handleCopy;
   final VoidCallback? handleCut;
   final VoidCallback? handlePaste;
   final VoidCallback? handleSelectAll;
   final Offset selectionMidpoint;
   final double textLineHeight;

   @override
   _CupertinoTextSelectionControlsToolbarState createState() => _CupertinoTextSelectionControlsToolbarState();
 }

 class _CupertinoTextSelectionControlsToolbarState extends State<_CupertinoTextSelectionControlsToolbar> {
   ClipboardStatusNotifier? _clipboardStatus;

   void _onChangedClipboardStatus() {
     setState(() {
       // Inform the widget that the value of clipboardStatus has changed.
     });
   }

   @override
   void initState() {
     super.initState();
     if (widget.handlePaste != null) {
       _clipboardStatus = widget.clipboardStatus ?? ClipboardStatusNotifier();
       _clipboardStatus!.addListener(_onChangedClipboardStatus);
       _clipboardStatus!.update();
     }
   }

   @override
   void didUpdateWidget(_CupertinoTextSelectionControlsToolbar oldWidget) {
     super.didUpdateWidget(oldWidget);
     if (oldWidget.clipboardStatus != widget.clipboardStatus) {
       if (_clipboardStatus != null) {
         _clipboardStatus!.removeListener(_onChangedClipboardStatus);
         _clipboardStatus!.dispose();
       }
       _clipboardStatus = widget.clipboardStatus ?? ClipboardStatusNotifier();
       _clipboardStatus!.addListener(_onChangedClipboardStatus);
       if (widget.handlePaste != null) {
         _clipboardStatus!.update();
       }
     }
   }

   @override
   void dispose() {
     super.dispose();
     // When used in an Overlay, this can be disposed after its creator has
     // already disposed _clipboardStatus.
     if (_clipboardStatus != null && !_clipboardStatus!.disposed) {
       _clipboardStatus!.removeListener(_onChangedClipboardStatus);
       if (widget.clipboardStatus == null) {
         _clipboardStatus!.dispose();
       }
     }
   }

   @override
   Widget build(BuildContext context) {
     // Don't render the menu until the state of the clipboard is known.
     if (widget.handlePaste != null
         && _clipboardStatus!.value == ClipboardStatus.unknown) {
       return const SizedBox(width: 0.0, height: 0.0);
     }

     assert(debugCheckHasMediaQuery(context));
     final MediaQueryData mediaQuery = MediaQuery.of(context);

     // The toolbar should appear below the TextField when there is not enough
     // space above the TextField to show it, assuming there's always enough
     // space at the bottom in this case.
     final double anchorX = (widget.selectionMidpoint.dx + widget.globalEditableRegion.left).clamp(
       _kArrowScreenPadding + mediaQuery.padding.left,
       mediaQuery.size.width - mediaQuery.padding.right - _kArrowScreenPadding,
     );

     // The y-coordinate has to be calculated instead of directly quoting
     // selectionMidpoint.dy, since the caller
     // (TextSelectionOverlay._buildToolbar) does not know whether the toolbar is
     // going to be facing up or down.
     final Offset anchorAbove = Offset(
       anchorX,
       widget.endpoints.first.point.dy - widget.textLineHeight + widget.globalEditableRegion.top,
     );
     final Offset anchorBelow = Offset(
       anchorX,
       widget.endpoints.last.point.dy + widget.globalEditableRegion.top,
     );

     final List<Widget> items = <Widget>[];
     final CupertinoLocalizations localizations = CupertinoLocalizations.of(context);
     final Widget onePhysicalPixelVerticalDivider =
         SizedBox(width: 1.0 / MediaQuery.of(context).devicePixelRatio);

     void addToolbarButton(
       String text,
       VoidCallback onPressed,
     ) {
       if (items.isNotEmpty) {
         items.add(onePhysicalPixelVerticalDivider);
       }

       items.add(CupertinoTextSelectionToolbarButton.text(
         onPressed: onPressed,
         text: text,
       ));
     }

     if (widget.handleCut != null) {
       addToolbarButton(localizations.cutButtonLabel, widget.handleCut!);
     }
     if (widget.handleCopy != null) {
       addToolbarButton(localizations.copyButtonLabel, widget.handleCopy!);
     }
     if (widget.handlePaste != null
         && _clipboardStatus!.value == ClipboardStatus.pasteable) {
       addToolbarButton(localizations.pasteButtonLabel, widget.handlePaste!);
     }
     if (widget.handleSelectAll != null) {
       addToolbarButton(localizations.selectAllButtonLabel, widget.handleSelectAll!);
     }

     // If there is no option available, build an empty widget.
     if (items.isEmpty) {
       return const SizedBox(width: 0.0, height: 0.0);
     }

     return CupertinoTextSelectionToolbar(
       anchorAbove: anchorAbove,
       anchorBelow: anchorBelow,
       children: items,
     );
   }
 }

 /// Draws a single text selection handle with a bar and a ball.
 class _TextSelectionHandlePainter extends CustomPainter {
   const _TextSelectionHandlePainter(this.color);

   final Color color;

   @override
   void paint(Canvas canvas, Size size) {
     const double halfStrokeWidth = 1.0;
     final Paint paint = Paint()..color = color;
     final Rect circle = Rect.fromCircle(
       center: const Offset(_kSelectionHandleRadius, _kSelectionHandleRadius),
       radius: _kSelectionHandleRadius,
     );
     final Rect line = Rect.fromPoints(
       const Offset(
         _kSelectionHandleRadius - halfStrokeWidth,
         2 * _kSelectionHandleRadius - _kSelectionHandleOverlap,
       ),
       Offset(_kSelectionHandleRadius + halfStrokeWidth, size.height),
     );
     final Path path = Path()
       ..addOval(circle)
     // Draw line so it slightly overlaps the circle.
       ..addRect(line);
     canvas.drawPath(path, paint);
   }

   @override
   bool shouldRepaint(_TextSelectionHandlePainter oldPainter) => color != oldPainter.color;
 }

 /// iOS Cupertino styled text selection controls.
 class CupertinoTextSelectionControls extends TextSelectionControls {
   /// Returns the size of the Cupertino handle.
   @override
   Size getHandleSize(double textLineHeight) {
     return Size(
       _kSelectionHandleRadius * 2,
       textLineHeight + _kSelectionHandleRadius * 2 - _kSelectionHandleOverlap,
     );
   }

   /// Builder for iOS-style copy/paste text selection toolbar.
   @override
   Widget buildToolbar(
     BuildContext context,
     Rect globalEditableRegion,
     double textLineHeight,
     Offset selectionMidpoint,
     List<TextSelectionPoint> endpoints,
     TextSelectionDelegate delegate,
     ClipboardStatusNotifier clipboardStatus,
     Offset? lastSecondaryTapDownPosition,
   ) {
     return _CupertinoTextSelectionControlsToolbar(
       clipboardStatus: clipboardStatus,
       endpoints: endpoints,
       globalEditableRegion: globalEditableRegion,
       handleCut: canCut(delegate) ? () => handleCut(delegate) : null,
       handleCopy: canCopy(delegate) ? () => handleCopy(delegate, clipboardStatus) : null,
       handlePaste: canPaste(delegate) ? () => handlePaste(delegate) : null,
       handleSelectAll: canSelectAll(delegate) ? () => handleSelectAll(delegate) : null,
       selectionMidpoint: selectionMidpoint,
       textLineHeight: textLineHeight,
     );
   }

   /// Builder for iOS text selection edges.
   @override
   Widget buildHandle(BuildContext context, TextSelectionHandleType type, double textLineHeight) {
     // We want a size that's a vertical line the height of the text plus a 18.0
     // padding in every direction that will constitute the selection drag area.
     final Size desiredSize = getHandleSize(textLineHeight);

     final Widget handle = SizedBox.fromSize(
       size: desiredSize,
       child: CustomPaint(
         painter: _TextSelectionHandlePainter(CupertinoTheme.of(context).primaryColor),
       ),
     );

     // [buildHandle]'s widget is positioned at the selection cursor's bottom
     // baseline. We transform the handle such that the SizedBox is superimposed
     // on top of the text selection endpoints.
     switch (type) {
       case TextSelectionHandleType.left:
         return handle;
       case TextSelectionHandleType.right:
         // Right handle is a vertical mirror of the left.
         return Transform(
           transform: Matrix4.identity()
             ..translate(desiredSize.width / 2, desiredSize.height / 2)
             ..rotateZ(math.pi)
             ..translate(-desiredSize.width / 2, -desiredSize.height / 2),
           child: handle,
         );
       // iOS doesn't draw anything for collapsed selections.
       case TextSelectionHandleType.collapsed:
         return const SizedBox();
     }
   }

   /// Gets anchor for cupertino-style text selection handles.
   ///
   /// See [TextSelectionControls.getHandleAnchor].
   @override
   Offset getHandleAnchor(TextSelectionHandleType type, double textLineHeight) {
     final Size handleSize = getHandleSize(textLineHeight);
     switch (type) {
       // The circle is at the top for the left handle, and the anchor point is
       // all the way at the bottom of the line.
       case TextSelectionHandleType.left:
         return Offset(
           handleSize.width / 2,
           handleSize.height,
         );
       // The right handle is vertically flipped, and the anchor point is near
       // the top of the circle to give slight overlap.
       case TextSelectionHandleType.right:
         return Offset(
           handleSize.width / 2,
           handleSize.height - 2 * _kSelectionHandleRadius + _kSelectionHandleOverlap,
         );
       // A collapsed handle anchors itself so that it's centered.
       case TextSelectionHandleType.collapsed:
         return Offset(
           handleSize.width / 2,
           textLineHeight + (handleSize.height - textLineHeight) / 2,
         );
     }
   }
 }

 /// Text selection controls that follows iOS design conventions.
 final TextSelectionControls cupertinoTextSelectionControls = CupertinoTextSelectionControls();
	// 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.

	import 'dart:math' as math;

	import 'package:flutter/widgets.dart';
	import 'package:flutter/rendering.dart';
	import 'package:flutter/services.dart';

	import 'localizations.dart';
	import 'text_selection_toolbar.dart';
	import 'text_selection_toolbar_button.dart';
	import 'theme.dart';

	// Read off from the output on iOS 12. This color does not vary with the
	// application's theme color.
	const double _kSelectionHandleOverlap = 1.5;
	// Extracted from https://developer.apple.com/design/resources/.
	const double _kSelectionHandleRadius = 6;

	// Minimal padding from tip of the selection toolbar arrow to horizontal edges of the
	// screen. Eyeballed value.
	const double _kArrowScreenPadding = 26.0;

	// Generates the child that's passed into CupertinoTextSelectionToolbar.
	class _CupertinoTextSelectionControlsToolbar extends StatefulWidget {
	const _CupertinoTextSelectionControlsToolbar({
	Key? key,
	required this.clipboardStatus,
	required this.endpoints,
	required this.globalEditableRegion,
	required this.handleCopy,
	required this.handleCut,
	required this.handlePaste,
	required this.handleSelectAll,
	required this.selectionMidpoint,
	required this.textLineHeight,
	}) : super(key: key);

	final ClipboardStatusNotifier? clipboardStatus;
	final List<TextSelectionPoint> endpoints;
	final Rect globalEditableRegion;
	final VoidCallback? handleCopy;
	final VoidCallback? handleCut;
	final VoidCallback? handlePaste;
	final VoidCallback? handleSelectAll;
	final Offset selectionMidpoint;
	final double textLineHeight;

	@override
	_CupertinoTextSelectionControlsToolbarState createState() => _CupertinoTextSelectionControlsToolbarState();
	}

	class _CupertinoTextSelectionControlsToolbarState extends State<_CupertinoTextSelectionControlsToolbar> {
	ClipboardStatusNotifier? _clipboardStatus;

	void _onChangedClipboardStatus() {
	setState(() {
	// Inform the widget that the value of clipboardStatus has changed.
	});
	}

	@override
	void initState() {
	super.initState();
	if (widget.handlePaste != null) {
	_clipboardStatus = widget.clipboardStatus ?? ClipboardStatusNotifier();
	_clipboardStatus!.addListener(_onChangedClipboardStatus);
	_clipboardStatus!.update();
	}
	}

	@override
	void didUpdateWidget(_CupertinoTextSelectionControlsToolbar oldWidget) {
	super.didUpdateWidget(oldWidget);
	if (oldWidget.clipboardStatus != widget.clipboardStatus) {
	if (_clipboardStatus != null) {
	_clipboardStatus!.removeListener(_onChangedClipboardStatus);
	_clipboardStatus!.dispose();
	}
	_clipboardStatus = widget.clipboardStatus ?? ClipboardStatusNotifier();
	_clipboardStatus!.addListener(_onChangedClipboardStatus);
	if (widget.handlePaste != null) {
	_clipboardStatus!.update();
	}
	}
	}

	@override
	void dispose() {
	super.dispose();
	// When used in an Overlay, this can be disposed after its creator has
	// already disposed _clipboardStatus.
	if (_clipboardStatus != null && !_clipboardStatus!.disposed) {
	_clipboardStatus!.removeListener(_onChangedClipboardStatus);
	if (widget.clipboardStatus == null) {
	_clipboardStatus!.dispose();
	}
	}
	}

	@override
	Widget build(BuildContext context) {
	// Don't render the menu until the state of the clipboard is known.
	if (widget.handlePaste != null
	&& _clipboardStatus!.value == ClipboardStatus.unknown) {
	return const SizedBox(width: 0.0, height: 0.0);
	}

	assert(debugCheckHasMediaQuery(context));
	final MediaQueryData mediaQuery = MediaQuery.of(context);

	// The toolbar should appear below the TextField when there is not enough
	// space above the TextField to show it, assuming there's always enough
	// space at the bottom in this case.
	final double anchorX = (widget.selectionMidpoint.dx + widget.globalEditableRegion.left).clamp(
	_kArrowScreenPadding + mediaQuery.padding.left,
	mediaQuery.size.width - mediaQuery.padding.right - _kArrowScreenPadding,
	);

	// The y-coordinate has to be calculated instead of directly quoting
	// selectionMidpoint.dy, since the caller
	// (TextSelectionOverlay._buildToolbar) does not know whether the toolbar is
	// going to be facing up or down.
	final Offset anchorAbove = Offset(
	anchorX,
	widget.endpoints.first.point.dy - widget.textLineHeight + widget.globalEditableRegion.top,
	);
	final Offset anchorBelow = Offset(
	anchorX,
	widget.endpoints.last.point.dy + widget.globalEditableRegion.top,
	);

	final List<Widget> items = <Widget>[];
	final CupertinoLocalizations localizations = CupertinoLocalizations.of(context);
	final Widget onePhysicalPixelVerticalDivider =
	SizedBox(width: 1.0 / MediaQuery.of(context).devicePixelRatio);

	void addToolbarButton(
	String text,
	VoidCallback onPressed,
	) {
	if (items.isNotEmpty) {
	items.add(onePhysicalPixelVerticalDivider);
	}

	items.add(CupertinoTextSelectionToolbarButton.text(
	onPressed: onPressed,
	text: text,
	));
	}

	if (widget.handleCut != null) {
	addToolbarButton(localizations.cutButtonLabel, widget.handleCut!);
	}
	if (widget.handleCopy != null) {
	addToolbarButton(localizations.copyButtonLabel, widget.handleCopy!);
	}
	if (widget.handlePaste != null
	&& _clipboardStatus!.value == ClipboardStatus.pasteable) {
	addToolbarButton(localizations.pasteButtonLabel, widget.handlePaste!);
	}
	if (widget.handleSelectAll != null) {
	addToolbarButton(localizations.selectAllButtonLabel, widget.handleSelectAll!);
	}

	// If there is no option available, build an empty widget.
	if (items.isEmpty) {
	return const SizedBox(width: 0.0, height: 0.0);
	}

	return CupertinoTextSelectionToolbar(
	anchorAbove: anchorAbove,
	anchorBelow: anchorBelow,
	children: items,
	);
	}
	}

	/// Draws a single text selection handle with a bar and a ball.
	class _TextSelectionHandlePainter extends CustomPainter {
	const _TextSelectionHandlePainter(this.color);

	final Color color;

	@override
	void paint(Canvas canvas, Size size) {
	const double halfStrokeWidth = 1.0;
	final Paint paint = Paint()..color = color;
	final Rect circle = Rect.fromCircle(
	center: const Offset(_kSelectionHandleRadius, _kSelectionHandleRadius),
	radius: _kSelectionHandleRadius,
	);
	final Rect line = Rect.fromPoints(
	const Offset(
	_kSelectionHandleRadius - halfStrokeWidth,
	2 * _kSelectionHandleRadius - _kSelectionHandleOverlap,
	),
	Offset(_kSelectionHandleRadius + halfStrokeWidth, size.height),
	);
	final Path path = Path()
	..addOval(circle)
	// Draw line so it slightly overlaps the circle.
	..addRect(line);
	canvas.drawPath(path, paint);
	}

	@override
	bool shouldRepaint(_TextSelectionHandlePainter oldPainter) => color != oldPainter.color;
	}

	/// iOS Cupertino styled text selection controls.
	class CupertinoTextSelectionControls extends TextSelectionControls {
	/// Returns the size of the Cupertino handle.
	@override
	Size getHandleSize(double textLineHeight) {
	return Size(
	_kSelectionHandleRadius * 2,
	textLineHeight + _kSelectionHandleRadius * 2 - _kSelectionHandleOverlap,
	);
	}

	/// Builder for iOS-style copy/paste text selection toolbar.
	@override
	Widget buildToolbar(
	BuildContext context,
	Rect globalEditableRegion,
	double textLineHeight,
	Offset selectionMidpoint,
	List<TextSelectionPoint> endpoints,
	TextSelectionDelegate delegate,
	ClipboardStatusNotifier clipboardStatus,
	Offset? lastSecondaryTapDownPosition,
	) {
	return _CupertinoTextSelectionControlsToolbar(
	clipboardStatus: clipboardStatus,
	endpoints: endpoints,
	globalEditableRegion: globalEditableRegion,
	handleCut: canCut(delegate) ? () => handleCut(delegate) : null,
	handleCopy: canCopy(delegate) ? () => handleCopy(delegate, clipboardStatus) : null,
	handlePaste: canPaste(delegate) ? () => handlePaste(delegate) : null,
	handleSelectAll: canSelectAll(delegate) ? () => handleSelectAll(delegate) : null,
	selectionMidpoint: selectionMidpoint,
	textLineHeight: textLineHeight,
	);
	}

	/// Builder for iOS text selection edges.
	@override
	Widget buildHandle(BuildContext context, TextSelectionHandleType type, double textLineHeight) {
	// We want a size that's a vertical line the height of the text plus a 18.0
	// padding in every direction that will constitute the selection drag area.
	final Size desiredSize = getHandleSize(textLineHeight);

	final Widget handle = SizedBox.fromSize(
	size: desiredSize,
	child: CustomPaint(
	painter: _TextSelectionHandlePainter(CupertinoTheme.of(context).primaryColor),
	),
	);

	// [buildHandle]'s widget is positioned at the selection cursor's bottom
	// baseline. We transform the handle such that the SizedBox is superimposed
	// on top of the text selection endpoints.
	switch (type) {
	case TextSelectionHandleType.left:
	return handle;
	case TextSelectionHandleType.right:
	// Right handle is a vertical mirror of the left.
	return Transform(
	transform: Matrix4.identity()
	..translate(desiredSize.width / 2, desiredSize.height / 2)
	..rotateZ(math.pi)
	..translate(-desiredSize.width / 2, -desiredSize.height / 2),
	child: handle,
	);
	// iOS doesn't draw anything for collapsed selections.
	case TextSelectionHandleType.collapsed:
	return const SizedBox();
	}
	}

	/// Gets anchor for cupertino-style text selection handles.
	///
	/// See [TextSelectionControls.getHandleAnchor].
	@override
	Offset getHandleAnchor(TextSelectionHandleType type, double textLineHeight) {
	final Size handleSize = getHandleSize(textLineHeight);
	switch (type) {
	// The circle is at the top for the left handle, and the anchor point is
	// all the way at the bottom of the line.
	case TextSelectionHandleType.left:
	return Offset(
	handleSize.width / 2,
	handleSize.height,
	);
	// The right handle is vertically flipped, and the anchor point is near
	// the top of the circle to give slight overlap.
	case TextSelectionHandleType.right:
	return Offset(
	handleSize.width / 2,
	handleSize.height - 2 * _kSelectionHandleRadius + _kSelectionHandleOverlap,
	);
	// A collapsed handle anchors itself so that it's centered.
	case TextSelectionHandleType.collapsed:
	return Offset(
	handleSize.width / 2,
	textLineHeight + (handleSize.height - textLineHeight) / 2,
	);
	}
	}
	}

	/// Text selection controls that follows iOS design conventions.
	final TextSelectionControls cupertinoTextSelectionControls = CupertinoTextSelectionControls();