117 строки
3.1 KiB
C#
117 строки
3.1 KiB
C#
//
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// DelegatedCommand.cs
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//
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// Author:
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// Eric Maupin <ermau@xamarin.com>
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//
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// Copyright (c) 2012 Xamarin, Inc.
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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using System;
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using System.Collections.Generic;
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using System.Windows.Input;
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namespace Xwt.WPFBackend
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{
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internal class DelegatedCommand<T>
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: DelegatedCommand
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{
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public DelegatedCommand (Action<T> execute)
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: base (s => execute ((T)s))
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{
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if (execute == null)
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throw new ArgumentNullException ("execute");
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}
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public DelegatedCommand (Action<T> execute, Func<T, bool> canExecute)
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: base (s => execute ((T)s), s => canExecute ((T)s))
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{
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if (execute == null)
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throw new ArgumentNullException ("execute");
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if (canExecute == null)
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throw new ArgumentNullException ("canExecute");
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}
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}
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internal class DelegatedCommand
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: ICommand
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{
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public DelegatedCommand (Action<object> execute)
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: this (execute, s => true)
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{
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}
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public DelegatedCommand (Action<object> execute, Func<object, bool> canExecute)
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{
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if (execute == null)
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throw new ArgumentNullException ("execute");
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if (canExecute == null)
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throw new ArgumentNullException ("canExecute");
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this.execute = execute;
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this.canExecute = canExecute;
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}
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public event EventHandler CanExecuteChanged
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{
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add
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{
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if (this.listeners.Count == 0)
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CommandManager.RequerySuggested += RequerySuggested;
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this.listeners.Add (value);
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}
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remove
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{
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this.listeners.Remove (value);
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if (this.listeners.Count == 0)
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CommandManager.RequerySuggested -= RequerySuggested;
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}
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}
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public void Execute (object parameter)
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{
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this.execute (parameter);
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}
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public bool CanExecute (object parameter)
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{
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return this.canExecute (parameter);
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}
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public void NotifyExecutabilityChanged()
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{
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for (int i = 0; i < this.listeners.Count; ++i)
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this.listeners [i] (this, EventArgs.Empty);
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}
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private readonly Action<object> execute;
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private readonly Func<object, bool> canExecute;
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private readonly List<EventHandler> listeners = new List<EventHandler> ();
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private void RequerySuggested (object sender, EventArgs eventArgs)
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{
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NotifyExecutabilityChanged();
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}
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}
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} |