100 lines
3.3 KiB
C#
100 lines
3.3 KiB
C#
using Avalonia.Controls;
|
|
using System;
|
|
using System.Collections;
|
|
using System.Collections.Generic;
|
|
using System.ComponentModel;
|
|
using System.Linq;
|
|
using System.Text;
|
|
using System.Threading.Tasks;
|
|
|
|
namespace LibationWinForms.AvaloniaUI.ViewModels
|
|
{
|
|
//TODO keep episodes beneath their parents when other entries compare equal (because as it stands, children always compare > parents.
|
|
/// <summary>
|
|
/// This compare class ensures that all top-level grid entries (standalone books or series parents)
|
|
/// are sorted by PropertyName while all episodes remain immediately beneath their parents and remain
|
|
/// sorted by series index, ascending.
|
|
/// </summary>
|
|
internal class RowComparer : IComparer
|
|
{
|
|
private static readonly System.Reflection.PropertyInfo HeaderCellPi = typeof(DataGridColumn).GetProperty("HeaderCell", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
|
|
private static readonly System.Reflection.PropertyInfo CurrentSortingStatePi = typeof(DataGridColumnHeader).GetProperty("CurrentSortingState", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
|
|
|
|
public DataGridColumn Column { get; init; }
|
|
public string PropertyName { get; private set; }
|
|
public ListSortDirection? SortDirection { get; set; }
|
|
|
|
public RowComparer(DataGridColumn column)
|
|
{
|
|
Column = column;
|
|
PropertyName = Column.SortMemberPath;
|
|
}
|
|
|
|
|
|
public int Compare(object x, object y)
|
|
{
|
|
if (x is null && y is not null) return -1;
|
|
if (x is not null && y is null) return 1;
|
|
if (x is null && y is null) return 0;
|
|
|
|
var geA = (GridEntry2)x;
|
|
var geB = (GridEntry2)y;
|
|
|
|
SortDirection ??= GetSortOrder();
|
|
|
|
SeriesEntrys2 parentA = null;
|
|
SeriesEntrys2 parentB = null;
|
|
|
|
if (geA is LibraryBookEntry2 lbA && lbA.Parent is SeriesEntrys2 seA)
|
|
parentA = seA;
|
|
if (geB is LibraryBookEntry2 lbB && lbB.Parent is SeriesEntrys2 seB)
|
|
parentB = seB;
|
|
|
|
|
|
|
|
//both a and b are standalone
|
|
if (parentA is null && parentB is null)
|
|
return Compare(geA, geB);
|
|
|
|
//a is a standalone, b is a child
|
|
if (parentA is null && parentB is not null)
|
|
{
|
|
// b is a child of a, parent is always first
|
|
if (parentB == geA)
|
|
return SortDirection is ListSortDirection.Ascending ? -1 : 1;
|
|
else
|
|
return Compare(geA, parentB);
|
|
}
|
|
|
|
//a is a child, b is a standalone
|
|
if (parentA is not null && parentB is null)
|
|
{
|
|
// a is a child of b, parent is always first
|
|
if (parentA == geB)
|
|
return SortDirection is ListSortDirection.Ascending ? 1 : -1;
|
|
else
|
|
return Compare(parentA, geB);
|
|
}
|
|
|
|
//both are children of the same series, always present in order of series index, ascending
|
|
if (parentA == parentB)
|
|
return geA.SeriesIndex.CompareTo(geB.SeriesIndex) * (SortDirection is ListSortDirection.Ascending ? 1 : -1);
|
|
|
|
//a and b are children of different series.
|
|
return Compare(parentA, parentB);
|
|
}
|
|
|
|
//Avalonia doesn't expose the column's CurrentSortingState, so we must get it through reflection
|
|
private ListSortDirection? GetSortOrder()
|
|
=> CurrentSortingStatePi.GetValue(HeaderCellPi.GetValue(Column)) as ListSortDirection?;
|
|
|
|
private int Compare(GridEntry2 x, GridEntry2 y)
|
|
{
|
|
var val1 = x.GetMemberValue(PropertyName);
|
|
var val2 = y.GetMemberValue(PropertyName);
|
|
|
|
return x.GetMemberComparer(val1.GetType()).Compare(val1, val2);
|
|
}
|
|
}
|
|
}
|