fix typo

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

lib/common/widgets/dynamic_sliver_app_bar/rendering/sliver_persistent_header.dart

@@ -0,0 +1,285 @@
+/*
+ * This file is part of PiliPlus
+ *
+ * PiliPlus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * PiliPlus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with PiliPlus.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+import 'dart:math' as math;
+
+import 'package:PiliPlus/common/widgets/dynamic_sliver_app_bar/sliver_persistent_header.dart';
+import 'package:PiliPlus/common/widgets/only_layout_widget.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/rendering.dart' hide LayoutCallback;
+import 'package:flutter/widgets.dart'
+    hide SliverPersistentHeader, SliverPersistentHeaderDelegate;
+
+/// ref [SliverPersistentHeader]
+
+Rect? _trim(
+  Rect? original, {
+  double top = -double.infinity,
+  double right = double.infinity,
+  double bottom = double.infinity,
+  double left = -double.infinity,
+}) => original?.intersect(Rect.fromLTRB(left, top, right, bottom));
+
+abstract class RenderSliverPersistentHeader extends RenderSliver
+    with RenderObjectWithChildMixin<RenderBox>, RenderSliverHelpers {
+  RenderSliverPersistentHeader({RenderBox? child}) {
+    this.child = child;
+  }
+
+  SliverPersistentHeaderElement? element;
+
+  double get minExtent =>
+      (element!.widget as SliverPinnedHeader).delegate.minExtent;
+
+  bool _needsUpdateChild = true;
+
+  double get lastShrinkOffset => _lastShrinkOffset;
+  double _lastShrinkOffset = 0.0;
+
+  bool get lastOverlapsContent => _lastOverlapsContent;
+  bool _lastOverlapsContent = false;
+
+  @protected
+  void updateChild(
+    double shrinkOffset,
+    bool overlapsContent,
+    double? maxExtent,
+  ) {
+    assert(element != null);
+    element!.build(shrinkOffset, overlapsContent, maxExtent);
+  }
+
+  @override
+  void markNeedsLayout() {
+    _needsUpdateChild = true;
+    super.markNeedsLayout();
+  }
+
+  @protected
+  void updateChildIfNeeded(
+    double scrollOffset,
+    double? maxExtent, {
+    bool overlapsContent = false,
+  }) {
+    final double shrinkOffset = maxExtent == null
+        ? scrollOffset
+        : math.min(scrollOffset, maxExtent);
+    if (_needsUpdateChild ||
+        _lastShrinkOffset != shrinkOffset ||
+        _lastOverlapsContent != overlapsContent) {
+      invokeLayoutCallback<SliverConstraints>((SliverConstraints constraints) {
+        assert(constraints == this.constraints);
+        updateChild(shrinkOffset, overlapsContent, maxExtent);
+      });
+      _lastShrinkOffset = shrinkOffset;
+      _lastOverlapsContent = overlapsContent;
+      _needsUpdateChild = false;
+    }
+  }
+
+  @override
+  double childMainAxisPosition(covariant RenderObject child) =>
+      super.childMainAxisPosition(child);
+
+  @override
+  bool hitTestChildren(
+    SliverHitTestResult result, {
+    required double mainAxisPosition,
+    required double crossAxisPosition,
+  }) {
+    assert(geometry!.hitTestExtent > 0.0);
+    if (child != null) {
+      return hitTestBoxChild(
+        BoxHitTestResult.wrap(result),
+        child!,
+        mainAxisPosition: mainAxisPosition,
+        crossAxisPosition: crossAxisPosition,
+      );
+    }
+    return false;
+  }
+
+  @override
+  void applyPaintTransform(RenderObject child, Matrix4 transform) {
+    assert(child == this.child);
+    applyPaintTransformForBoxChild(child as RenderBox, transform);
+  }
+
+  void triggerRebuild() {
+    markNeedsLayout();
+  }
+}
+
+class SliverPinnedHeader extends RenderObjectWidget {
+  const SliverPinnedHeader({
+    super.key,
+    required this.delegate,
+    this.onPerformLayout,
+  });
+
+  final SliverPersistentHeaderDelegate delegate;
+  final LayoutCallback? onPerformLayout;
+
+  @override
+  SliverPersistentHeaderElement createElement() =>
+      SliverPersistentHeaderElement(this);
+
+  @override
+  RenderSliverPinnedHeader createRenderObject(BuildContext context) {
+    return RenderSliverPinnedHeader(onPerformLayout: onPerformLayout);
+  }
+
+  @override
+  void updateRenderObject(
+    BuildContext context,
+    RenderSliverPinnedHeader renderObject,
+  ) {
+    renderObject.onPerformLayout = onPerformLayout;
+  }
+}
+
+class RenderSliverPinnedHeader extends RenderSliverPersistentHeader {
+  RenderSliverPinnedHeader({
+    super.child,
+    this.onPerformLayout,
+  });
+
+  LayoutCallback? onPerformLayout;
+
+  ({double crossAxisExtent, double maxExtent})? _maxExtent;
+  double? get maxExtent => _maxExtent?.maxExtent;
+
+  void _rawLayout() {
+    child!.layout(constraints.asBoxConstraints(), parentUsesSize: true);
+    _maxExtent = (
+      crossAxisExtent: constraints.crossAxisExtent,
+      maxExtent: child!.size.height,
+    );
+    onPerformLayout?.call(child!.size);
+  }
+
+  void _layout() {
+    final double shrinkOffset = math.min(
+      constraints.scrollOffset,
+      _maxExtent!.maxExtent,
+    );
+    child!.layout(
+      constraints.asBoxConstraints(
+        maxExtent: math.max(minExtent, _maxExtent!.maxExtent - shrinkOffset),
+      ),
+      parentUsesSize: true,
+    );
+  }
+
+  @override
+  void performLayout() {
+    final constraints = this.constraints;
+    final bool overlapsContent = constraints.overlap > 0.0;
+
+    if (_maxExtent == null) {
+      updateChildIfNeeded(
+        constraints.scrollOffset,
+        _maxExtent?.maxExtent,
+        overlapsContent: overlapsContent,
+      );
+      _rawLayout();
+    } else {
+      if (_maxExtent!.crossAxisExtent == constraints.crossAxisExtent) {
+        updateChildIfNeeded(
+          constraints.scrollOffset,
+          _maxExtent?.maxExtent,
+          overlapsContent: overlapsContent,
+        );
+        _layout();
+      } else {
+        _needsUpdateChild = true;
+        updateChildIfNeeded(
+          constraints.scrollOffset,
+          null,
+          overlapsContent: overlapsContent,
+        );
+        _rawLayout();
+        if (constraints.scrollOffset > 0.0) {
+          _needsUpdateChild = true;
+          updateChildIfNeeded(
+            constraints.scrollOffset,
+            _maxExtent?.maxExtent,
+            overlapsContent: overlapsContent,
+          );
+          _layout();
+        }
+      }
+    }
+    final childExtent = child!.size.height;
+    final maxExtent = _maxExtent!.maxExtent;
+    final double effectiveRemainingPaintExtent = math.max(
+      0,
+      constraints.remainingPaintExtent - constraints.overlap,
+    );
+    final double layoutExtent = clampDouble(
+      maxExtent - constraints.scrollOffset,
+      0.0,
+      effectiveRemainingPaintExtent,
+    );
+    geometry = SliverGeometry(
+      scrollExtent: maxExtent,
+      paintOrigin: constraints.overlap,
+      paintExtent: math.min(childExtent, effectiveRemainingPaintExtent),
+      layoutExtent: layoutExtent,
+      maxPaintExtent: maxExtent,
+      maxScrollObstructionExtent: minExtent,
+      cacheExtent: layoutExtent > 0.0
+          ? -constraints.cacheOrigin + layoutExtent
+          : layoutExtent,
+      hasVisualOverflow: false,
+    );
+  }
+
+  @override
+  void paint(PaintingContext context, Offset offset) {
+    if (child != null && geometry!.visible) {
+      context.paintChild(child!, offset);
+    }
+  }
+
+  @override
+  double childMainAxisPosition(RenderBox child) => 0.0;
+
+  @override
+  void showOnScreen({
+    RenderObject? descendant,
+    Rect? rect,
+    Duration duration = Duration.zero,
+    Curve curve = Curves.ease,
+  }) {
+    final Rect? localBounds = descendant != null
+        ? MatrixUtils.transformRect(
+            descendant.getTransformTo(this),
+            rect ?? descendant.paintBounds,
+          )
+        : rect;
+
+    final Rect? newRect = _trim(localBounds, top: 0);
+
+    super.showOnScreen(
+      descendant: this,
+      rect: newRect,
+      duration: duration,
+      curve: curve,
+    );
+  }
+}