opt fab location

Signed-off-by: dom <githubaccount56556@proton.me>

lib/pages/common/fab_mixin.dart

@@ -0,0 +1,78 @@
+import 'package:flutter/material.dart';
+
+mixin FabMixin<T extends StatefulWidget> on State<T>, TickerProvider {
+  bool _isFabVisible = true;
+  late final AnimationController _fabAnimationCtr;
+  late final Animation<Offset> fabAnimation;
+
+  @override
+  void initState() {
+    super.initState();
+    _fabAnimationCtr = AnimationController(
+      vsync: this,
+      duration: const Duration(milliseconds: 100),
+    );
+    fabAnimation = _fabAnimationCtr.drive(
+      Tween<Offset>(
+        begin: Offset.zero,
+        end: const Offset(0.0, 1.0),
+      ).chain(CurveTween(curve: Curves.easeInOut)),
+    );
+  }
+
+  void showFab() {
+    if (!_isFabVisible) {
+      _isFabVisible = true;
+      _fabAnimationCtr.reverse();
+    }
+  }
+
+  void hideFab() {
+    if (_isFabVisible) {
+      _isFabVisible = false;
+      _fabAnimationCtr.forward();
+    }
+  }
+
+  @override
+  void dispose() {
+    _fabAnimationCtr.dispose();
+    super.dispose();
+  }
+}
+
+mixin _NoRightMarginMixin on StandardFabLocation {
+  @override
+  double getOffsetX(scaffoldGeometry, _) {
+    return scaffoldGeometry.scaffoldSize.width -
+        scaffoldGeometry.minInsets.right -
+        scaffoldGeometry.floatingActionButtonSize.width;
+  }
+}
+
+mixin _NoBottomPaddingMixin on StandardFabLocation {
+  @override
+  double getOffsetY(scaffoldGeometry, _) {
+    return scaffoldGeometry.contentBottom -
+        scaffoldGeometry.floatingActionButtonSize.height;
+  }
+}
+
+class NoRightMarginFabLocation extends StandardFabLocation
+    with FabFloatOffsetY, _NoRightMarginMixin {
+  const NoRightMarginFabLocation();
+}
+
+class NoBottomPaddingFabLocation extends StandardFabLocation
+    with FabEndOffsetX, _NoBottomPaddingMixin {
+  const NoBottomPaddingFabLocation();
+}
+
+class ActionBarLocation extends StandardFabLocation with _NoBottomPaddingMixin {
+  const ActionBarLocation();
+
+  @override
+  double getOffsetX(scaffoldGeometry, _) {
+    return 0.0;
+  }
+}