选择线条颜色

lib/paper/color_selector.dart

@@ -0,0 +1,52 @@
+import 'package:flutter/material.dart';
+
+class ColorSelector extends StatelessWidget {
+  final List<Color> supportColors;
+  final ValueChanged<int> onSelect;
+  final int activeIndex;
+
+  const ColorSelector({
+    Key? key,
+    required this.supportColors,
+    required this.activeIndex,
+    required this.onSelect,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Padding(
+      padding: const EdgeInsets.symmetric(horizontal: 8.0, vertical: 8),
+      child: Wrap(
+          // crossAxisAlignment: CrossAxisAlignment.end,
+          children: List.generate(
+            supportColors.length,
+            _buildByIndex,
+          )),
+    );
+  }
+
+  Widget _buildByIndex(int index) {
+    bool select = index == activeIndex;
+    return GestureDetector(
+      onTap: () => onSelect(index),
+      child: Container(
+        margin: const EdgeInsets.symmetric(horizontal: 2),
+        padding: const EdgeInsets.all(2),
+        width: 24,
+        height: 24,
+        alignment: Alignment.center,
+        decoration: BoxDecoration(
+          shape: BoxShape.circle,
+            // borderRadius: BorderRadius.circular(8),
+            border: select ? Border.all(color: Colors.blue) : null
+        ),
+        child: Container(
+          decoration: BoxDecoration(
+              shape: BoxShape.circle,
+            color: supportColors[index],
+          ),
+        ),
+      ),
+    );
+  }
+}

lib/paper/paper.dart

@@ -2,6 +2,7 @@ import 'dart:math';
 import 'dart:ui';
 
 import 'package:flutter/material.dart';
+import 'package:flutter_first_station/paper/color_selector.dart';
 import 'package:flutter_first_station/paper/conform_dialog.dart';
 
 import 'model.dart';
@@ -31,6 +32,17 @@ class _PaperState extends State<Paper> {
     Colors.blue,
     Colors.indigo,
     Colors.purple,
+    Colors.pink,
+
+    // Colors.grey,
+    // Colors.redAccent,
+    // Colors.orangeAccent,
+    // Colors.yellowAccent,
+    // Colors.greenAccent,
+    // Colors.blueAccent,
+    // Colors.indigoAccent,
+    // Colors.purpleAccent,
+    // Colors.pinkAccent,
   ];
 
   // 支持的线粗
@@ -43,6 +55,7 @@ class _PaperState extends State<Paper> {
         onClear: _showClearDialog,
       ),
       body: Stack(
+        alignment: Alignment.bottomLeft,
         children: [
           GestureDetector(
             onPanStart: _onPanStart,
@@ -52,15 +65,24 @@ class _PaperState extends State<Paper> {
               child: ConstrainedBox(constraints: const BoxConstraints.expand()),
             ),
           ),
+          Positioned(
+            bottom: 40,
+            child: ColorSelector(
+              supportColors: supportColors,
+              activeIndex: _activeColorIndex,
+              onSelect: _onSelectColor,
+            ),
+          ),
           Positioned(
             bottom: 0,
             right: 10,
             child:  StorkWidthSelector(
               supportStorkWidths: supportStorkWidths,
-                color: Colors.black,
+              color: supportColors[_activeColorIndex],
               activeIndex: _activeStorkWidthIndex,
               onSelect: _onSelectStorkWidth,
-              )),
+            )
+          ),
         ],
       ),
     );
@@ -88,6 +110,7 @@ class _PaperState extends State<Paper> {
     _lines.add(Line(
       points: [details.localPosition],
       strokeWidth: supportStorkWidths[_activeStorkWidthIndex],
+      color: supportColors[_activeColorIndex],
     ));
   }
 
@@ -103,6 +126,14 @@ class _PaperState extends State<Paper> {
       });
     }
   }
+
+  void _onSelectColor(int index) {
+    if (index != _activeColorIndex) {
+      setState(() {
+        _activeColorIndex = index;
+      });
+    }
+  }
 }
 
 class PaperPainter extends CustomPainter {