| | | 1 | | using System; |
| | | 2 | | using System.Collections.Generic; |
| | | 3 | | using System.Diagnostics.CodeAnalysis; |
| | | 4 | | using System.Linq; |
| | | 5 | | |
| | | 6 | | namespace Amusoft.Toolkit.Mvvm.Core; |
| | | 7 | | |
| | | 8 | | internal abstract class NavigationModel |
| | | 9 | | { |
| | 0 | 10 | | public NavigationModel(Type modelType) |
| | | 11 | | { |
| | 0 | 12 | | ModelType = modelType; |
| | 0 | 13 | | } |
| | | 14 | | |
| | 0 | 15 | | public Type ModelType { get; set; } |
| | | 16 | | |
| | | 17 | | public abstract bool TryGetModelInstance([NotNullWhen(true)] out object? model); |
| | | 18 | | } |
| | | 19 | | |
| | | 20 | | internal class NavigationModel<T> : NavigationModel where T : class |
| | | 21 | | { |
| | | 22 | | private readonly IRestoreStrategy<T>[] _restoreStrategies; |
| | | 23 | | |
| | | 24 | | public NavigationModel(T model, IRestoreStrategy<T>[] restoreStrategies) : base(model.GetType()) |
| | | 25 | | { |
| | | 26 | | _restoreStrategies = restoreStrategies; |
| | | 27 | | _modelReference = new WeakReference<T>(model); |
| | | 28 | | foreach (var restoreStrategy in restoreStrategies) |
| | | 29 | | { |
| | | 30 | | restoreStrategy.CollectRestoreInformation(model); |
| | | 31 | | } |
| | | 32 | | } |
| | | 33 | | |
| | | 34 | | private WeakReference<T> _modelReference; |
| | | 35 | | |
| | | 36 | | public override bool TryGetModelInstance([NotNullWhen(true)] out object? model) |
| | | 37 | | { |
| | | 38 | | model = null; |
| | | 39 | | if (_modelReference.TryGetTarget(out var typedModel)) |
| | | 40 | | { |
| | | 41 | | model = typedModel; |
| | | 42 | | return true; |
| | | 43 | | } |
| | | 44 | | |
| | | 45 | | var restoredModel = _restoreStrategies.OrderByDescending(d => d.Priority) |
| | | 46 | | .FirstOrDefault()? |
| | | 47 | | .Recreate(); |
| | | 48 | | |
| | | 49 | | if (restoredModel == null) |
| | | 50 | | return false; |
| | | 51 | | |
| | | 52 | | _modelReference = new WeakReference<T>(restoredModel); |
| | | 53 | | model = restoredModel; |
| | | 54 | | return true; |
| | | 55 | | } |
| | | 56 | | } |