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lib/cases/paper/paper_app_bar.dart

@@ -0,0 +1,76 @@
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+
+class PaperAppBar extends StatelessWidget implements PreferredSizeWidget {
+  final VoidCallback onClear;
+  final VoidCallback? onBack;
+  final VoidCallback? onRevocation;
+
+  const PaperAppBar({
+    Key? key,
+    required this.onClear,
+    this.onBack,
+    this.onRevocation,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return AppBar(
+      leading: BackUpButtons(
+        onBack: onBack,
+        onRevocation: onRevocation,
+      ),
+      leadingWidth: 100,
+      title: Text('画板绘制'),
+      actions: [
+        IconButton(
+            splashRadius: 20,
+            onPressed: onClear,
+            icon: Icon(CupertinoIcons.delete, size: 20))
+      ],
+    );
+  }
+
+  @override
+  Size get preferredSize => const Size.fromHeight(kToolbarHeight);
+}
+
+class BackUpButtons extends StatelessWidget {
+  final VoidCallback? onBack;
+  final VoidCallback? onRevocation;
+
+  const BackUpButtons({
+    Key? key,
+    required this.onBack,
+    required this.onRevocation,
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    const BoxConstraints cts = BoxConstraints(minHeight: 32, minWidth: 32);
+    Color backColor = onBack ==null?Colors.grey:Colors.black;
+    Color revocationColor = onRevocation ==null?Colors.grey:Colors.black;
+    return Center(
+      child: Wrap(
+        children: [
+          Transform.scale(
+            scaleX: -1,
+            child: IconButton(
+              splashRadius: 20,
+              constraints: cts,
+              onPressed: onBack,
+              icon: Icon(Icons.next_plan_outlined,color: backColor),
+            ),
+          ),
+          IconButton(
+            splashRadius: 20,
+            onPressed: onRevocation,
+            constraints: cts,
+            icon: Icon(Icons.next_plan_outlined, color: revocationColor),
+          )
+        ],
+      ),
+    );
+  }
+}