generated from dellevin/template
111 lines
2.9 KiB
Dart
111 lines
2.9 KiB
Dart
import 'package:flutter/material.dart';
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/// 选区手柄（起点和终点各一个），可拖动调整选区范围
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///
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/// 样式：光标竖线 + 大圆点
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/// - 起点手柄：圆点在上，竖线向下连接到选区起点
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/// - 终点手柄：竖线从选区终点向下延伸，圆点在下
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class SelectionHandles extends StatelessWidget {
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final Offset? startPosition;
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final Offset? endPosition;
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final Function(DragUpdateDetails) onDragStart;
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final Function(DragUpdateDetails) onDragEnd;
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static const double _circleSize = 12.0;
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static const double _lineHeight = 20.0;
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static const double _lineWidth = 2.0;
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static const Color _handleColor = Color(0xFF4A90D9);
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const SelectionHandles({
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super.key,
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required this.startPosition,
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required this.endPosition,
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required this.onDragStart,
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required this.onDragEnd,
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});
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@override
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Widget build(BuildContext context) {
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return Stack(
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children: [
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if (startPosition != null) _buildStartHandle(startPosition!),
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if (endPosition != null) _buildEndHandle(endPosition!),
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],
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);
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}
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/// 起点手柄：圆点在上 + 竖线向下
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/// startPosition 在文字行底部，手柄线覆盖文字行，圆点在文字上方
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Widget _buildStartHandle(Offset pos) {
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final totalHeight = _circleSize + _lineHeight;
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return Positioned(
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left: pos.dx - _circleSize / 2,
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top: pos.dy - totalHeight,
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child: GestureDetector(
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behavior: HitTestBehavior.translucent,
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onPanUpdate: onDragStart,
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child: SizedBox(
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width: _circleSize,
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height: totalHeight,
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child: Column(
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children: [
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_buildCircle(),
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_buildLine(),
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],
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),
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),
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),
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);
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}
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/// 终点手柄：竖线向下 + 圆点在下
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/// endPosition 在文字行顶部，手柄线覆盖文字行，圆点在文字下方
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Widget _buildEndHandle(Offset pos) {
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final totalHeight = _lineHeight + _circleSize;
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return Positioned(
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left: pos.dx - _circleSize / 2,
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top: pos.dy,
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child: GestureDetector(
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behavior: HitTestBehavior.translucent,
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onPanUpdate: onDragEnd,
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child: SizedBox(
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width: _circleSize,
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height: totalHeight,
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child: Column(
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children: [
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_buildLine(),
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_buildCircle(),
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],
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),
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),
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),
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);
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}
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Widget _buildCircle() {
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return Container(
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width: _circleSize,
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height: _circleSize,
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decoration: BoxDecoration(
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color: _handleColor,
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shape: BoxShape.circle,
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boxShadow: const [
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BoxShadow(
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color: Color(0x33000000),
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blurRadius: 3,
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offset: Offset(0, 1),
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),
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],
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),
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);
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}
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Widget _buildLine() {
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return Container(
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width: _lineWidth,
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height: _lineHeight,
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color: _handleColor,
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);
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}
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}
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