42 lines
1 KiB
C#
42 lines
1 KiB
C#
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using System.Windows.Input;
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namespace CatalogLite;
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public sealed class AsyncCommand : ICommand
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{
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private readonly Func<Task> _execute;
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private readonly Func<bool>? _canExecute;
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private bool _isExecuting;
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public AsyncCommand(Func<Task> execute, Func<bool>? canExecute = null)
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{
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_execute = execute ?? throw new ArgumentNullException(nameof(execute));
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_canExecute = canExecute;
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}
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public event EventHandler? CanExecuteChanged;
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public bool CanExecute(object? parameter) => !_isExecuting && (_canExecute?.Invoke() ?? true);
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public async void Execute(object? parameter)
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{
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if (!CanExecute(parameter))
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{
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return;
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}
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try
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{
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_isExecuting = true;
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RaiseCanExecuteChanged();
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await _execute().ConfigureAwait(false);
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}
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finally
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{
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_isExecuting = false;
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RaiseCanExecuteChanged();
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}
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}
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public void RaiseCanExecuteChanged() => CanExecuteChanged?.Invoke(this, EventArgs.Empty);
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}
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