Add AppBar.adaptive (#2458)

* AppBar.adaptive

* add support for AppBar.adaptive

package/lib/src/controls/app_bar.dart

@@ -1,8 +1,10 @@
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 
 import '../models/control.dart';
 import '../utils/colors.dart';
 import 'create_control.dart';
+import 'cupertino_app_bar.dart';
 
 class AppBarControl extends StatelessWidget implements PreferredSizeWidget {
   final Control? parent;
@@ -23,6 +25,18 @@ class AppBarControl extends StatelessWidget implements PreferredSizeWidget {
   Widget build(BuildContext context) {
     debugPrint("AppBar build: ${control.id}");
 
+    bool adaptive = control.attrBool("adaptive", false)!;
+    if (adaptive &&
+        (defaultTargetPlatform == TargetPlatform.iOS ||
+            defaultTargetPlatform == TargetPlatform.macOS)) {
+      return CupertinoAppBarControl(
+        control: control,
+        parentDisabled: parentDisabled,
+        children: children,
+        bgcolor: HexColor.fromString(
+            Theme.of(context), control.attrString("bgcolor", "")!));
+    }
+
     var leadingCtrls =
         children.where((c) => c.name == "leading" && c.isVisible);
     var titleCtrls = children.where((c) => c.name == "title" && c.isVisible);

package/lib/src/controls/cupertino_app_bar.dart

@@ -29,9 +29,14 @@ class CupertinoAppBarControl extends StatelessWidget
 
     var leadingCtrls =
         children.where((c) => c.name == "leading" && c.isVisible);
-    var middleCtrls = children.where((c) => c.name == "middle" && c.isVisible);
-    var trailingCtrls =
-        children.where((c) => c.name == "trailing" && c.isVisible);
+
+    // if the material AppBar was used with adaptive=True, AppBar.title will be used as middle control
+    var middleCtrls = children
+        .where((c) => (c.name == "middle" || c.name == "title") && c.isVisible);
+
+    // if the material AppBar was used with adaptive=True, AppBar.actions[0] will be used as trailing control
+    var trailingCtrls = children.where(
+        (c) => (c.name == "trailing" || c.name == "action") && c.isVisible);
 
     var automaticallyImplyLeading =
         control.attrBool("automaticallyImplyLeading", true)!;

sdk/python/packages/flet-core/src/flet_core/app_bar.py

@@ -61,6 +61,7 @@ def __init__(
         bgcolor: Optional[str] = None,
         elevation: OptionalNumber = None,
         actions: Optional[List[Control]] = None,
+        adaptive: Optional[bool] = None,
     ):
         Control.__init__(self, ref=ref)
 
@@ -78,6 +79,7 @@ def __init__(
         self.bgcolor = bgcolor
         self.elevation = elevation
         self.actions = actions
+        self.adaptive = adaptive
 
     def _get_control_name(self):
         return "appbar"
@@ -191,3 +193,12 @@ def actions(self):
     @actions.setter
     def actions(self, value):
         self.__actions = value if value is not None else []
+
+    # adaptive
+    @property
+    def adaptive(self) -> Optional[bool]:
+        return self._get_attr("adaptive", data_type="bool", def_value=False)
+
+    @adaptive.setter
+    def adaptive(self, value: Optional[bool]):
+        self._set_attr("adaptive", value)