v1: Rename ConstrainedControl to LayoutControl, swap Button and ElevatedButton (#5592)

* Replace ConstrainedControl with LayoutControl

Refactored all usages of ConstrainedControl to LayoutControl across control implementations. Introduced LayoutControl as the new wrapper for layout constraints, with ConstrainedControl now extending LayoutControl for backward compatibility. Updated documentation and example paths to reflect the new naming and organization.

* Refactor ElevatedButton to Button and update references

Replaces the ElevatedButton control with Button throughout the codebase, consolidating button logic into a single Button class. ElevatedButton is now a deprecated alias for Button. Updates all usages, tests, and control registration to use Button, simplifying the API and improving maintainability.

* Replace ElevatedButton with Button in examples

Updated all Python example files to use ft.Button instead of ft.ElevatedButton for consistency with the latest Flet API. This affects authentication, controls-gallery, routing-navigation, studio-gallery, desktop-window-manager, and other sample apps.

* Refactor calculator UI to use Colors and content

Replaces deprecated 'colors' import with 'Colors' and updates Button controls to use 'content' instead of 'text'. Also changes alignment to use MainAxisAlignment.END and updates class inheritance from UserControl to Container for improved compatibility with Flet API.

Author: FeodorFitsner

packages/flet/lib/src/controls/animated_switcher.dart

@@ -47,6 +47,6 @@ class AnimatedSwitcherControl extends StatelessWidget {
       },
       child: content,
     );
-    return ConstrainedControl(control: control, child: animatedSwitcher);
+    return LayoutControl(control: control, child: animatedSwitcher);
   }
 }

packages/flet/lib/src/controls/base_controls.dart

@@ -29,11 +29,20 @@ class BaseControl extends StatelessWidget {
   }
 }
 
-class ConstrainedControl extends StatelessWidget {
+// TODO - remove when extensions migrated to LayoutControl
+class ConstrainedControl extends LayoutControl {
+  const ConstrainedControl({
+    super.key,
+    required super.control,
+    required super.child,
+  });
+}
+
+class LayoutControl extends StatelessWidget {
   final Control control;
   final Widget child;
 
-  const ConstrainedControl({
+  const LayoutControl({
     super.key,
     required this.control,
     required this.child,

packages/flet/lib/src/controls/bottom_app_bar.dart

@@ -22,6 +22,6 @@ class BottomAppBarControl extends StatelessWidget {
       child: control.buildWidget("content"),
     );
 
-    return ConstrainedControl(control: control, child: bottomAppBar);
+    return LayoutControl(control: control, child: bottomAppBar);
   }
 }

packages/flet/lib/src/controls/button.dart

@@ -218,6 +218,6 @@ class _ButtonControlState extends State<ButtonControl> with FletStoreMixin {
       }
     }
 
-    return ConstrainedControl(control: widget.control, child: button);
+    return LayoutControl(control: widget.control, child: button);
   }
 }

packages/flet/lib/src/controls/canvas.dart

@@ -167,7 +167,7 @@ class _CanvasControlState extends State<CanvasControl> {
       child: widget.control.buildWidget("content"),
     );
 
-    return ConstrainedControl(control: widget.control, child: paint);
+    return LayoutControl(control: widget.control, child: paint);
   }
 }
 

packages/flet/lib/src/controls/card.dart

@@ -77,6 +77,6 @@ class CardControl extends StatelessWidget {
           child: contentWidget);
     }
 
-    return ConstrainedControl(control: control, child: card);
+    return LayoutControl(control: control, child: card);
   }
 }

packages/flet/lib/src/controls/checkbox.dart

@@ -136,6 +136,6 @@ class _CheckboxControlState extends State<CheckboxControl> {
           child: FittedBox(fit: BoxFit.fill, child: result));
     }
 
-    return ConstrainedControl(control: widget.control, child: result);
+    return LayoutControl(control: widget.control, child: result);
   }
 }

packages/flet/lib/src/controls/chip.dart

@@ -136,6 +136,6 @@ class _ChipControlState extends State<ChipControl> {
           : null,
     );
 
-    return ConstrainedControl(control: widget.control, child: chip);
+    return LayoutControl(control: widget.control, child: chip);
   }
 }

packages/flet/lib/src/controls/circle_avatar.dart

@@ -72,6 +72,6 @@ class CircleAvatarControl extends StatelessWidget {
             : null,
         child: content);
 
-    return ConstrainedControl(control: control, child: avatar);
+    return LayoutControl(control: control, child: avatar);
   }
 }

packages/flet/lib/src/controls/column.dart

@@ -59,6 +59,6 @@ class ColumnControl extends StatelessWidget {
       child = ScrollNotificationControl(control: control, child: child);
     }
 
-    return ConstrainedControl(control: control, child: child);
+    return LayoutControl(control: control, child: child);
   }
 }