Files
PiliPlus/lib/utils/grid.dart

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4.5 KiB
Dart

import 'dart:math';
import 'package:flutter/cupertino.dart';
import 'package:flutter/rendering.dart';
import 'storage.dart';
class Grid {
static double maxRowWidth = GStrorage.setting.get(SettingBoxKey.maxRowWidth, defaultValue: 240.0) as double;
//
// static double calculateActualWidth(BuildContext context, double maxCrossAxisExtent, double crossAxisSpacing, {double? screenWidthOffset}) {
// double screenWidth = MediaQuery.of(context).size.width;
// if (screenWidthOffset != null) {
// screenWidth -= screenWidthOffset;
// }
// if (GStrorage.setting.get(SettingBoxKey.adaptiveNavBar, defaultValue: false) as bool) {
// screenWidth -= 55;
// }
// int columnCount = ((screenWidth - crossAxisSpacing) / (maxCrossAxisExtent + crossAxisSpacing)).ceil();
// if (columnCount < 1){
// columnCount = 1;
// }
// double columnWidth = (screenWidth - crossAxisSpacing) ~/ columnCount - crossAxisSpacing;
// return columnWidth;
// }
}
class SliverGridDelegateWithExtentAndRatio extends SliverGridDelegate {
/// Creates a delegate that makes grid layouts with tiles that have a maximum
/// cross-axis extent.
///
/// The [maxCrossAxisExtent], [mainAxisExtent], [mainAxisSpacing],
/// and [crossAxisSpacing] arguments must not be negative.
/// The [childAspectRatio] argument must be greater than zero.
const SliverGridDelegateWithExtentAndRatio({
required this.maxCrossAxisExtent,
this.mainAxisSpacing = 0.0,
this.crossAxisSpacing = 0.0,
this.childAspectRatio = 1.0,
this.mainAxisExtent = 0.0,
}) : assert(maxCrossAxisExtent > 0),
assert(mainAxisSpacing >= 0),
assert(crossAxisSpacing >= 0),
assert(childAspectRatio > 0);
/// The maximum extent of tiles in the cross axis.
///
/// This delegate will select a cross-axis extent for the tiles that is as
/// large as possible subject to the following conditions:
///
/// - The extent evenly divides the cross-axis extent of the grid.
/// - The extent is at most [maxCrossAxisExtent].
///
/// For example, if the grid is vertical, the grid is 500.0 pixels wide, and
/// [maxCrossAxisExtent] is 150.0, this delegate will create a grid with 4
/// columns that are 125.0 pixels wide.
final double maxCrossAxisExtent;
/// The number of logical pixels between each child along the main axis.
final double mainAxisSpacing;
/// The number of logical pixels between each child along the cross axis.
final double crossAxisSpacing;
/// The ratio of the cross-axis to the main-axis extent of each child.
final double childAspectRatio;
/// The extent of each tile in the main axis. If provided, it would add
/// after [childAspectRatio] is used.
final double mainAxisExtent;
bool _debugAssertIsValid(double crossAxisExtent) {
assert(crossAxisExtent > 0.0);
assert(maxCrossAxisExtent > 0.0);
assert(mainAxisSpacing >= 0.0);
assert(crossAxisSpacing >= 0.0);
assert(childAspectRatio > 0.0);
return true;
}
@override
SliverGridLayout getLayout(SliverConstraints constraints) {
assert(_debugAssertIsValid(constraints.crossAxisExtent));
int crossAxisCount = ((constraints.crossAxisExtent - crossAxisSpacing) / (maxCrossAxisExtent + crossAxisSpacing)).ceil();
// Ensure a minimum count of 1, can be zero and result in an infinite extent
// below when the window size is 0.
crossAxisCount = max(1, crossAxisCount);
final double usableCrossAxisExtent = max(
0.0,
constraints.crossAxisExtent - crossAxisSpacing * (crossAxisCount - 1),
);
final double childCrossAxisExtent = usableCrossAxisExtent / crossAxisCount;
final double childMainAxisExtent = childCrossAxisExtent / childAspectRatio + mainAxisExtent;
return SliverGridRegularTileLayout(
crossAxisCount: crossAxisCount,
mainAxisStride: childMainAxisExtent + mainAxisSpacing,
crossAxisStride: childCrossAxisExtent + crossAxisSpacing,
childMainAxisExtent: childMainAxisExtent,
childCrossAxisExtent: childCrossAxisExtent,
reverseCrossAxis: axisDirectionIsReversed(constraints.crossAxisDirection),
);
}
@override
bool shouldRelayout(SliverGridDelegateWithExtentAndRatio oldDelegate) {
return oldDelegate.maxCrossAxisExtent != maxCrossAxisExtent
|| oldDelegate.mainAxisSpacing != mainAxisSpacing
|| oldDelegate.crossAxisSpacing != crossAxisSpacing
|| oldDelegate.childAspectRatio != childAspectRatio
|| oldDelegate.mainAxisExtent != mainAxisExtent;
}
}