From 3870dfeb289a7ae8f23196020e38bb47456687f2 Mon Sep 17 00:00:00 2001
From: Vadim <44135514+vodemn@users.noreply.github.com>
Date: Thu, 24 Oct 2024 12:09:11 +0200
Subject: [PATCH] added bottom widget to `SliverScreen`

---
 .../shared/sliver_screen/screen_sliver.dart   | 33 +++++++++++--------
 lib/utils/text_height.dart                    |  4 +++
 2 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/lib/screens/shared/sliver_screen/screen_sliver.dart b/lib/screens/shared/sliver_screen/screen_sliver.dart
index b4ae69d..a0de0e4 100644
--- a/lib/screens/shared/sliver_screen/screen_sliver.dart
+++ b/lib/screens/shared/sliver_screen/screen_sliver.dart
@@ -1,15 +1,18 @@
 import 'package:flutter/material.dart';
 import 'package:lightmeter/generated/l10n.dart';
 import 'package:lightmeter/res/dimens.dart';
+import 'package:lightmeter/utils/text_height.dart';
 
 class SliverScreen extends StatelessWidget {
   final Widget title;
   final List<Widget> appBarActions;
+  final PreferredSizeWidget? bottom;
   final List<Widget> slivers;
 
   const SliverScreen({
     required this.title,
     this.appBarActions = const [],
+    this.bottom,
     required this.slivers,
     super.key,
   });
@@ -24,7 +27,7 @@ class SliverScreen extends StatelessWidget {
           slivers: <Widget>[
             SliverAppBar.large(
               automaticallyImplyLeading: false,
-              expandedHeight: Dimens.sliverAppBarExpandedHeight,
+              expandedHeight: Dimens.sliverAppBarExpandedHeight + (bottom?.preferredSize.height ?? 0.0),
               flexibleSpace: FlexibleSpaceBar(
                 centerTitle: false,
                 titlePadding: const EdgeInsets.symmetric(horizontal: Dimens.paddingM),
@@ -37,10 +40,12 @@ class SliverScreen extends StatelessWidget {
                   overflow: TextOverflow.ellipsis,
                   child: _Title(
                     actionsCount: appBarActions.length + (Navigator.of(context).canPop() ? 1 : 0),
+                    bottomSize: bottom?.preferredSize.height ?? 0.0,
                     child: title,
                   ),
                 ),
               ),
+              bottom: bottom,
               actions: [
                 ...appBarActions,
                 if (Navigator.of(context).canPop())
@@ -62,35 +67,37 @@ class SliverScreen extends StatelessWidget {
 class _Title extends StatelessWidget {
   final Widget child;
   final int actionsCount;
+  final double bottomSize;
   final double actionsPadding;
 
   const _Title({
     required this.actionsCount,
+    required this.bottomSize,
     required this.child,
   }) : actionsPadding = Dimens.grid48 * actionsCount - Dimens.paddingM;
 
   @override
   Widget build(BuildContext context) {
     final settings = context.dependOnInheritedWidgetOfExactType<FlexibleSpaceBarSettings>()!;
-    final titleScale = _titleScale(settings);
+    final extentScale =
+        ((settings.maxExtent - settings.currentExtent) / (settings.maxExtent - settings.minExtent)).clamp(0.0, 1.0);
+    final titleScale = Tween<double>(begin: 1.5, end: 1.0).transform(extentScale);
     final maxFromTextToAppbar = settings.maxExtent - settings.minExtent - Dimens.paddingM;
     final currentFromTextToAppbar = settings.currentExtent - settings.minExtent - Dimens.paddingM;
     final actionsPaddingScale = (1 - currentFromTextToAppbar / maxFromTextToAppbar).clamp(0.0, 1.0);
 
     return LayoutBuilder(
-      builder: (context, constraints) => SizedBox(
-        height: settings.minExtent - MediaQuery.paddingOf(context).top,
-        width: constraints.maxWidth - (actionsPadding * actionsPaddingScale) / titleScale,
-        child: Align(
-          alignment: Alignment.centerLeft,
-          child: child,
+      builder: (context, constraints) => Padding(
+        padding: EdgeInsets.only(bottom: (Dimens.paddingM * (1 - actionsPaddingScale) + bottomSize) / titleScale),
+        child: SizedBox(
+          height: DefaultTextStyle.of(context).style.lineHeight * 2,
+          width: constraints.maxWidth - (actionsPadding * actionsPaddingScale) / titleScale,
+          child: Align(
+            alignment: FractionalOffset(0.0, 0.5 + 0.5 * (1 - extentScale)),
+            child: child,
+          ),
         ),
       ),
     );
   }
-
-  double _titleScale(FlexibleSpaceBarSettings s) {
-    final extentScale = ((s.maxExtent - s.currentExtent) / (s.maxExtent - s.minExtent)).clamp(0.0, 1.0);
-    return Tween<double>(begin: 1.5, end: 1.0).transform(extentScale);
-  }
 }
diff --git a/lib/utils/text_height.dart b/lib/utils/text_height.dart
index 6c3afa4..3c0faee 100644
--- a/lib/utils/text_height.dart
+++ b/lib/utils/text_height.dart
@@ -34,3 +34,7 @@ Size textSize(
   )..layout(maxWidth: maxWidth);
   return titlePainter.size;
 }
+
+extension TextLineHeight on TextStyle {
+  double get lineHeight => fontSize! * height!;
+}