Line data    Source code

       1             : // Copyright 2023 The terCAD team. All rights reserved.
       2             : // Use of this source code is governed by a CC BY-NC-ND 4.0 license that can be found in the LICENSE file.
       3             : 
       4             : import 'package:flutter/material.dart';
       5             : 
       6             : class DotsIndicatorDecoration extends Decoration {
       7             :   final PageController controller;
       8             :   final int itemCount;
       9             :   final Color color;
      10             :   final double dotSize;
      11             :   final double _spacing;
      12             : 
      13           1 :   const DotsIndicatorDecoration({
      14             :     required this.controller,
      15             :     required this.itemCount,
      16             :     required this.color,
      17             :     required this.dotSize,
      18             :     double? spacing,
      19             :   }) : _spacing = spacing ?? dotSize;
      20             : 
      21           1 :   @override
      22             :   BoxPainter createBoxPainter([VoidCallback? onChanged]) {
      23           1 :     return _CustomTabIndicatorPainter(
      24           1 :       controller: controller,
      25           1 :       itemCount: itemCount,
      26           1 :       color: color,
      27           1 :       dotSize: dotSize,
      28           1 :       spacing: _spacing,
      29             :       onChanged: onChanged,
      30             :     );
      31             :   }
      32             : }
      33             : 
      34             : class _CustomTabIndicatorPainter extends BoxPainter {
      35             :   final PageController controller;
      36             :   final int itemCount;
      37             :   final Color color;
      38             :   final double dotSize;
      39             :   final double spacing;
      40             : 
      41           1 :   _CustomTabIndicatorPainter({
      42             :     required this.controller,
      43             :     required this.itemCount,
      44             :     required this.color,
      45             :     required this.dotSize,
      46             :     required this.spacing,
      47             :     VoidCallback? onChanged,
      48           1 :   }) : super(onChanged);
      49             : 
      50           1 :   @override
      51             :   void paint(Canvas canvas, Offset offset, ImageConfiguration configuration) {
      52           2 :     if (itemCount <= 1) {
      53             :       return;
      54             :     }
      55           3 :     final activeIndex = controller.page?.round() ?? controller.initialPage;
      56           3 :     final active = Paint()..color = color;
      57           4 :     final inactive = Paint()..color = color.withOpacity(0.3);
      58           3 :     for (int i = 0; i < itemCount; i++) {
      59           6 :       double xPos = spacing + i * (dotSize + spacing);
      60           2 :       double yPos = spacing * 0.6;
      61           1 :       if (i == activeIndex) {
      62           4 :         canvas.drawCircle(Offset(xPos, yPos), dotSize / 2, active);
      63             :       } else {
      64           4 :         canvas.drawCircle(Offset(xPos, yPos), dotSize / 2, inactive);
      65             :       }
      66             :     }
      67             :   }
      68             : }