Added threaded action to wrap sub-actions a view model can perform (this can either be scheduled individually or on the parent threaded view model); added missing copyright statement; more unit tests
git-svn-id: file:///srv/devel/repo-conversion/nuwi@45 d2e56fa2-650e-0410-a79f-9358c0239efd
This commit is contained in:
parent
9aa64c4dac
commit
14d0ea1371
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@ -57,10 +57,15 @@
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<Compile Include="Properties\AssemblyInfo.cs" />
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<Compile Include="Source\AutoBinding\ConventionBinder.cs" />
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<Compile Include="Source\AutoBinding\IAutoBinder.cs" />
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<Compile Include="Source\NullActiveWindowTracker.cs" />
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<Compile Include="Source\ViewModels\DialogViewModel.cs" />
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<Compile Include="Source\ViewModels\DialogViewModel.Test.cs">
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<DependentUpon>DialogViewModel.cs</DependentUpon>
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</Compile>
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<Compile Include="Source\ViewModels\ThreadedAction.cs" />
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<Compile Include="Source\ViewModels\ThreadedAction.Test.cs">
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<DependentUpon>ThreadedAction.cs</DependentUpon>
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</Compile>
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<Compile Include="Source\ViewModels\ThreadedDialogViewModel.cs" />
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<Compile Include="Source\ViewModels\ThreadedDialogViewModel.Test.cs">
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<DependentUpon>ThreadedDialogViewModel.cs</DependentUpon>
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@ -79,6 +84,9 @@
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<SubType>Form</SubType>
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</Compile>
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<Compile Include="Source\WindowManager.cs" />
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<Compile Include="Source\WindowManager.Test.cs">
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<DependentUpon>WindowManager.cs</DependentUpon>
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</Compile>
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<EmbeddedResource Include="Source\ProgressReporter\ProgressReporterForm.resx">
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<DependentUpon>ProgressReporterForm.cs</DependentUpon>
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<SubType>Designer</SubType>
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@ -7,9 +7,9 @@ using System.Runtime.InteropServices;
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// associated with an assembly.
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[assembly: AssemblyTitle("Nuclex.Windows.Forms")]
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[assembly: AssemblyProduct("Nuclex.Windows.Forms")]
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[assembly: AssemblyDescription("")]
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[assembly: AssemblyDescription("Lean and elegant MVVM library with extras for WinForms")]
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[assembly: AssemblyCompany("Nuclex Development Labs")]
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[assembly: AssemblyCopyright("Copyright © Nuclex Development Labs 2007")]
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[assembly: AssemblyCopyright("Copyright © Nuclex Development Labs 2019")]
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[assembly: AssemblyTrademark("")]
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[assembly: AssemblyCulture("")]
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37
Source/NullActiveWindowTracker.cs
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37
Source/NullActiveWindowTracker.cs
Normal file
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@ -0,0 +1,37 @@
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#region CPL License
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/*
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Nuclex Framework
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Copyright (C) 2002-2019 Nuclex Development Labs
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This library is free software; you can redistribute it and/or
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modify it under the terms of the IBM Common Public License as
|
||||
published by the IBM Corporation; either version 1.0 of the
|
||||
License, or (at your option) any later version.
|
||||
|
||||
This library is distributed in the hope that it will be useful,
|
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but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
IBM Common Public License for more details.
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You should have received a copy of the IBM Common Public
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License along with this library
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*/
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#endregion
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using System;
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using System.Windows.Forms;
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namespace Nuclex.Windows.Forms {
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/// <summary>Dummy implementation of the active window tracker service</summary>
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internal class NullActiveWindowTracker : IActiveWindowTracker {
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/// <summary>The default instance of the dummy window tracker</summary>
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public static readonly NullActiveWindowTracker Default = new NullActiveWindowTracker();
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/// <summary>The currently active top-level or modal window</summary>
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public Form ActiveWindow { get { return null; } }
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}
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} // namespace Nuclex.Windows.Forms
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@ -1,4 +1,26 @@
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using System;
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#region CPL License
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/*
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Nuclex Framework
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Copyright (C) 2002-2019 Nuclex Development Labs
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|
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This library is free software; you can redistribute it and/or
|
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modify it under the terms of the IBM Common Public License as
|
||||
published by the IBM Corporation; either version 1.0 of the
|
||||
License, or (at your option) any later version.
|
||||
|
||||
This library is distributed in the hope that it will be useful,
|
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but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
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IBM Common Public License for more details.
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You should have received a copy of the IBM Common Public
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License along with this library
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*/
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#endregion
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#if UNITTEST
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using System;
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using NUnit.Framework;
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@ -130,3 +152,5 @@ namespace Nuclex.Windows.Forms.ViewModels {
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}
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} // namespace Nuclex.Windows.Forms.ViewModels
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#endif // UNITTEST
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|
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271
Source/ViewModels/ThreadedAction.Test.cs
Normal file
271
Source/ViewModels/ThreadedAction.Test.cs
Normal file
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@ -0,0 +1,271 @@
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#region CPL License
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/*
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Nuclex Framework
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Copyright (C) 2002-2019 Nuclex Development Labs
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|
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This library is free software; you can redistribute it and/or
|
||||
modify it under the terms of the IBM Common Public License as
|
||||
published by the IBM Corporation; either version 1.0 of the
|
||||
License, or (at your option) any later version.
|
||||
|
||||
This library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
IBM Common Public License for more details.
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|
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You should have received a copy of the IBM Common Public
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License along with this library
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*/
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#endregion
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#if UNITTEST
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using System;
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using System.ComponentModel;
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using System.Threading;
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using NUnit.Framework;
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namespace Nuclex.Windows.Forms.ViewModels {
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/// <summary>Unit test for the threaded action class</summary>
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[TestFixture]
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public class ThreadedActionTest {
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#region class DummyContext
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/// <summary>Synchronization context that does absolutely nothing</summary>
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private class DummyContext : ISynchronizeInvoke {
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#region class SimpleAsyncResult
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/// <summary>Barebones implementation of an asynchronous result</summary>
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private class SimpleAsyncResult : IAsyncResult {
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/// <summary>Ehether the asynchronous operation is complete</summary>
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/// <remarks>
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/// Always true because it completes synchronously
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/// </remarks>
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public bool IsCompleted { get { return true; } }
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/// <summary>
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/// Wait handle that can be used to wait for the asynchronous operation
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/// </summary>
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public WaitHandle AsyncWaitHandle {
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get { throw new NotImplementedException("Not implemented"); }
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}
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/// <summary>Custom state that can be used to pass information around</summary>
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public object AsyncState {
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get { throw new NotImplementedException("Not implemented"); }
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}
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/// <summary>Whether the asynchronous operation completed synchronously</summary>
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public bool CompletedSynchronously { get { return true; } }
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/// <summary>The value returned from the asynchronous operation</summary>
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public object ReturnedValue;
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}
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#endregion // class SimpleAsyncResult
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/// <summary>Whether the calling thread needs to use Invoke()</summary>
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public bool InvokeRequired {
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get { return true; }
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}
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/// <summary>Schedules the specified method for execution in the target thread</summary>
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/// <param name="method">Method the target thread will execute when it is idle</param>
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/// <param name="arguments">Arguments that will be passed to the method</param>
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/// <returns>
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/// An asynchronous result handle that can be used to check on the status of
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/// the call and wait for its completion
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/// </returns>
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public IAsyncResult BeginInvoke(Delegate method, object[] arguments) {
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var asyncResult = new SimpleAsyncResult();
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asyncResult.ReturnedValue = method.Method.Invoke(method.Target, arguments);
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return asyncResult;
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}
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/// <summary>Waits for the asychronous call to complete</summary>
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/// <param name="result">
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/// Asynchronous result handle returned by the <see cref="BeginInvoke" /> method
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/// </param>
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/// <returns>The original result returned by the asychronously called method</returns>
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public object EndInvoke(IAsyncResult result) {
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return ((SimpleAsyncResult)result).ReturnedValue;
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}
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/// <summary>
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/// Schedules the specified method for execution in the target thread and waits
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/// for it to complete
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/// </summary>
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/// <param name="method">Method that will be executed by the target thread</param>
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/// <param name="arguments">Arguments that will be passed to the method</param>
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/// <returns>The result returned by the specified method</returns>
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public object Invoke(Delegate method, object[] arguments) {
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return method.Method.Invoke(method.Target, arguments);
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}
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}
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#endregion // class DummyContext
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#region class DummyThreadedAction
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/// <summary>Implementation of a threaded action for the unit test</summary>
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private class DummyThreadedAction : ThreadedAction {
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/// <summary>
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/// Initializes a new threaded action, letting the base class figure out the UI thread
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/// </summary>
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public DummyThreadedAction() : base() {
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this.finishedGate = new ManualResetEvent(initialState: false);
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}
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/// <summary>
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/// Initializes a new view model using the specified UI context explicitly
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/// </summary>
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public DummyThreadedAction(ISynchronizeInvoke uiContext) : base(uiContext) {
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this.finishedGate = new ManualResetEvent(initialState: false);
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}
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/// <summary>Immediately releases all resources owned by the instance</summary>
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public override void Dispose() {
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base.Dispose();
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if(this.finishedGate != null) {
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this.finishedGate.Dispose();
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this.finishedGate = null;
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}
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}
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/// <summary>Waits until the first background operation is finished</summary>
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/// <returns>
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/// True if the background operation is finished, false if it is ongoing
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/// </returns>
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public bool WaitUntilFinished() {
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return this.finishedGate.WaitOne(100);
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}
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/// <summary>Selects the value that will be assigned when the action runs</summary>
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/// <param name="valueToAssign">Value the action will assigned when it runs</param>
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public void SetValueToAssign(int valueToAssign) {
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this.valueToAssign = valueToAssign;
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}
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/// <summary>Sets up an error the action will fail with when run</summary>
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/// <param name="errorToFailWith">Error the action will fail with</param>
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public void SetErrorToFailWith(Exception errorToFailWith) {
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this.errorToFailWith = errorToFailWith;
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}
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/// <summary>Last error that was reported by the threaded view model</summary>
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public Exception ReportedError {
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get { return this.reportedError; }
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}
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/// <summary>Value that has been assigned from the background thread</summary>
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public int AssignedValue {
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get { return this.assignedValue; }
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}
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/// <summary>Executes the threaded action from the background thread</summary>
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/// <param name="cancellationToken">Token by which execution can be canceled</param>
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protected override void Run(CancellationToken cancellationToken) {
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if(this.errorToFailWith != null) {
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throw this.errorToFailWith;
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}
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this.assignedValue = this.valueToAssign;
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this.finishedGate.Set();
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}
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/// <summary>Called when an error occurs in the background thread</summary>
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/// <param name="exception">Exception that was thrown in the background thread</param>
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protected override void ReportError(Exception exception) {
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this.reportedError = exception;
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this.finishedGate.Set();
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}
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/// <summary>Error the action will fail with, if set</summary>
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private Exception errorToFailWith;
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/// <summary>Value the action will assign to its same-named field</summary>
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private int valueToAssign;
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/// <summary>Last error that was reported by the threaded view model</summary>
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private volatile Exception reportedError;
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/// <summary>Triggered when the </summary>
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private ManualResetEvent finishedGate;
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/// <summary>Value that is assigned through the background thread</summary>
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private volatile int assignedValue;
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}
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#endregion // class DummyThreadedAction
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/// <summary>Verifies that the threaded action has a default constructor</summary>
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[Test, Explicit]
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public void HasDefaultConstructor() {
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using(var mainForm = new System.Windows.Forms.Form()) {
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mainForm.Show();
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try {
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mainForm.Visible = false;
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using(new DummyThreadedAction()) { }
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}
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finally {
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mainForm.Close();
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}
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||||
}
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||||
}
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|
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/// <summary>
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/// Verifies that the threaded action can be constructed with a custom UI context
|
||||
/// </summary>
|
||||
[Test]
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||||
public void HasCustomSychronizationContextConstructor() {
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using(new DummyThreadedAction(new DummyContext())) { }
|
||||
}
|
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|
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/// <summary>Checks that a new threadd action starts out idle and not busy</summary>
|
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[Test]
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public void NewInstanceIsNotBusy() {
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using(var action = new DummyThreadedAction(new DummyContext())) {
|
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Assert.IsFalse(action.IsBusy);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Verifies that errors happening in the background processing threads are
|
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/// reported to the main thread
|
||||
/// </summary>
|
||||
[Test]
|
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public void ErrorsInBackgroundThreadAreReported() {
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using(var action = new DummyThreadedAction(new DummyContext())) {
|
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var testError = new ArgumentException("Mooh");
|
||||
action.SetErrorToFailWith(testError);
|
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action.Start();
|
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action.WaitUntilFinished();
|
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Assert.AreSame(testError, action.ReportedError);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Verifies that the background thread actually executes and can do work
|
||||
/// </summary>
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[Test]
|
||||
public void BackgroundThreadExecutesTasks() {
|
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using(var action = new DummyThreadedAction(new DummyContext())) {
|
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action.SetValueToAssign(42001);
|
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action.Start();
|
||||
action.WaitUntilFinished();
|
||||
Assert.AreEqual(42001, action.AssignedValue);
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
} // namespace Nuclex.Windows.Forms.ViewModels
|
||||
|
||||
#endif // UNITTEST
|
412
Source/ViewModels/ThreadedAction.cs
Normal file
412
Source/ViewModels/ThreadedAction.cs
Normal file
|
@ -0,0 +1,412 @@
|
|||
#region CPL License
|
||||
/*
|
||||
Nuclex Framework
|
||||
Copyright (C) 2002-2019 Nuclex Development Labs
|
||||
|
||||
This library is free software; you can redistribute it and/or
|
||||
modify it under the terms of the IBM Common Public License as
|
||||
published by the IBM Corporation; either version 1.0 of the
|
||||
License, or (at your option) any later version.
|
||||
|
||||
This library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
IBM Common Public License for more details.
|
||||
|
||||
You should have received a copy of the IBM Common Public
|
||||
License along with this library
|
||||
*/
|
||||
#endregion
|
||||
|
||||
using System;
|
||||
using System.ComponentModel;
|
||||
using System.Threading;
|
||||
using System.Windows.Forms;
|
||||
|
||||
using Nuclex.Support;
|
||||
using Nuclex.Support.Threading;
|
||||
|
||||
// Possible problem:
|
||||
//
|
||||
// After Run() is called, the action may not actually run if
|
||||
// it is using another thread runner and that one is cancelled.
|
||||
//
|
||||
// Thus, a second call to Run() has to schedule the action again,
|
||||
// even if it might already be scheduled, but should also not execute
|
||||
// the action a second time if is was indeed still scheduled.
|
||||
|
||||
namespace Nuclex.Windows.Forms.ViewModels {
|
||||
|
||||
/// <summary>Encapsulates an action that can run in a thread</summary>
|
||||
/// <remarks>
|
||||
/// <para>
|
||||
/// Sometimes a view model wants to allow multiple actions to take place
|
||||
/// at the same time. Think multiple panels on the view require updating
|
||||
/// from a web service - you can make both requests at the same time
|
||||
/// instead of sequentially.
|
||||
/// </para>
|
||||
/// <para>
|
||||
/// This class is also of use for things that need to be done sequentially
|
||||
/// by sharing the thread runner of the threaded view model. That way,
|
||||
/// you still have cancellable actions you can run at will and they
|
||||
/// automatically queue themselves to be executed one after another.
|
||||
/// </para>
|
||||
/// </remarks>
|
||||
public abstract class ThreadedAction : Observable, IDisposable {
|
||||
|
||||
#region class ThreadedActionThreadRunner
|
||||
|
||||
/// <summary>Thread runner for the threaded action</summary>
|
||||
private class ThreadedActionThreadRunner : ThreadRunner {
|
||||
|
||||
/// <summary>Initializes a new thread runner for the threaded view model</summary>
|
||||
public ThreadedActionThreadRunner(ThreadedAction viewModel) {
|
||||
this.threadedAction = viewModel;
|
||||
}
|
||||
|
||||
/// <summary>Reports an error</summary>
|
||||
/// <param name="exception">Error that will be reported</param>
|
||||
protected override void ReportError(Exception exception) {
|
||||
this.threadedAction.reportErrorFromThread(exception);
|
||||
}
|
||||
|
||||
/// <summary>Called when the status of the busy flag changes</summary>
|
||||
protected override void BusyChanged() {
|
||||
// Narf. Can't use this.
|
||||
}
|
||||
|
||||
/// <summary>View model the thread runner belongs to</summary>
|
||||
private ThreadedAction threadedAction;
|
||||
|
||||
}
|
||||
|
||||
#endregion // class ThreadedActionThreadRunner
|
||||
|
||||
/// <summary>Initializes all common fields of the instance</summary>
|
||||
private ThreadedAction() {
|
||||
this.callRunIfNotCancelledDelegate = new Action<CancellationTokenSource>(
|
||||
callThreadedExecuteIfNotCancelled
|
||||
);
|
||||
this.reportErrorDelegate = new Action<Exception>(ReportError);
|
||||
}
|
||||
|
||||
/// <summary>Initializes a threaded action that uses its own thread runner</summary>
|
||||
public ThreadedAction(ISynchronizeInvoke uiContext = null) : this() {
|
||||
if(uiContext == null) {
|
||||
this.uiContext = getMainWindow();
|
||||
} else {
|
||||
this.uiContext = uiContext;
|
||||
}
|
||||
|
||||
this.ownThreadRunner = new ThreadedActionThreadRunner(this);
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Initializes a threaded action that uses the view model's thread runner
|
||||
/// </summary>
|
||||
/// <param name="viewModel">View model whose thread runner will be used</param>
|
||||
/// <param name="uiContext">
|
||||
/// UI dispatcher that can be used to run callbacks in the UI thread
|
||||
/// </param>
|
||||
public ThreadedAction(
|
||||
ThreadedViewModel viewModel, ISynchronizeInvoke uiContext = null
|
||||
) : this() {
|
||||
if(uiContext == null) {
|
||||
this.uiContext = getMainWindow();
|
||||
} else {
|
||||
this.uiContext = uiContext;
|
||||
}
|
||||
|
||||
this.externalThreadRunner = viewModel.ThreadRunner;
|
||||
}
|
||||
|
||||
/// <summary>Immediately releases all resources owned by the instance</summary>
|
||||
public virtual void Dispose() {
|
||||
if(this.isBusy) {
|
||||
Cancel();
|
||||
}
|
||||
if(this.ownThreadRunner != null) {
|
||||
this.ownThreadRunner.Dispose();
|
||||
this.ownThreadRunner = null;
|
||||
}
|
||||
if(this.currentCancellationTokenSource != null) {
|
||||
this.currentCancellationTokenSource.Dispose();
|
||||
this.currentCancellationTokenSource = null;
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Whether the view model is currently busy executing a task</summary>
|
||||
public bool IsBusy {
|
||||
get { return this.isBusy; }
|
||||
private set {
|
||||
if(value != this.isBusy) {
|
||||
this.isBusy = value;
|
||||
OnPropertyChanged(nameof(IsBusy));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Cancels the running background task, if any</summary>
|
||||
public void Cancel() {
|
||||
lock(this.runningTaskSyncRoot) {
|
||||
|
||||
// If the background task is not running, do nothing. This also allows
|
||||
// us to avoid needless recreation of the same cancellation token source.
|
||||
if(!this.isBusy) {
|
||||
return;
|
||||
}
|
||||
|
||||
// If a task is currently running, cancel it
|
||||
if(this.isRunning) {
|
||||
if(this.currentCancellationTokenSource != null) {
|
||||
this.currentCancellationTokenSource.Cancel();
|
||||
this.currentCancellationTokenSource = null;
|
||||
}
|
||||
}
|
||||
|
||||
// If the task was scheduled to be repeated, we also have to mark
|
||||
// the upcoming cancellation token source as canceled because the scheduled
|
||||
// run will still be happening (it will just cancel out immediately).
|
||||
if(this.nextCancellationTokenSource != null) {
|
||||
this.nextCancellationTokenSource.Cancel();
|
||||
this.nextCancellationTokenSource = null;
|
||||
}
|
||||
this.isScheduledAgain = false;
|
||||
|
||||
// If the task was not running, we can clear the busy state because it
|
||||
// is not going to reach the running state.
|
||||
if(!this.isRunning) {
|
||||
this.isBusy = false;
|
||||
}
|
||||
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Starts the task, cancelling the running task before doing so
|
||||
/// </summary>
|
||||
public void Restart() {
|
||||
bool reportBusyChange = false;
|
||||
|
||||
lock(this.runningTaskSyncRoot) {
|
||||
|
||||
// If we're already in the execution phase, schedule another execution right
|
||||
// after this one is finished (because now, data might have changed after
|
||||
// execution has finished).
|
||||
if(this.isRunning) {
|
||||
//System.Diagnostics.Debug.WriteLine("Restart() - interrupting execution");
|
||||
if(this.currentCancellationTokenSource != null) {
|
||||
this.currentCancellationTokenSource.Cancel();
|
||||
}
|
||||
|
||||
this.currentCancellationTokenSource = this.nextCancellationTokenSource;
|
||||
this.nextCancellationTokenSource = null;
|
||||
this.isScheduledAgain = false;
|
||||
}
|
||||
|
||||
// If there's no cancellation token source, create one. If an execution
|
||||
// was already scheduled and the cancellation token source is still valid,
|
||||
// then reuse that in order to be able to cancel all scheduled executions.
|
||||
if(this.currentCancellationTokenSource == null) {
|
||||
//System.Diagnostics.Debug.WriteLine("Restart() - creating new cancellation token");
|
||||
this.currentCancellationTokenSource = new CancellationTokenSource();
|
||||
}
|
||||
|
||||
// Schedule another execution of the action
|
||||
scheduleExecution();
|
||||
|
||||
reportBusyChange = (this.isBusy == false);
|
||||
this.isBusy = true;
|
||||
}
|
||||
|
||||
if(reportBusyChange) {
|
||||
OnPropertyChanged(nameof(IsBusy));
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Starts the task</summary>
|
||||
public void Start() {
|
||||
bool reportBusyChange = false;
|
||||
|
||||
lock(this.runningTaskSyncRoot) {
|
||||
|
||||
// If we're already in the execution phase, schedule another execution right
|
||||
// after this one is finished (because now, data might have changed after
|
||||
// execution has finished).
|
||||
if(this.isRunning) {
|
||||
|
||||
// If we already created a new cancellation token source, keep it,
|
||||
// otherwise create a new one for the next execution
|
||||
if(!this.isScheduledAgain) {
|
||||
this.nextCancellationTokenSource = new CancellationTokenSource();
|
||||
this.isScheduledAgain = true;
|
||||
}
|
||||
|
||||
} else {
|
||||
|
||||
// If there's no cancellation token source, create one. If an execution
|
||||
// was already scheduled and the cancellation token source is still valid,
|
||||
// then reuse that in order to be able to cancel all scheduled executions.
|
||||
if(this.currentCancellationTokenSource == null) {
|
||||
this.currentCancellationTokenSource = new CancellationTokenSource();
|
||||
}
|
||||
|
||||
// Schedule another execution of the action
|
||||
scheduleExecution();
|
||||
|
||||
}
|
||||
|
||||
reportBusyChange = (this.isBusy == false);
|
||||
this.isBusy = true;
|
||||
}
|
||||
|
||||
if(reportBusyChange) {
|
||||
OnPropertyChanged(nameof(IsBusy));
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Reports an error</summary>
|
||||
/// <param name="exception">Error that will be reported</param>
|
||||
protected abstract void ReportError(Exception exception);
|
||||
|
||||
/// <summary>Executes the threaded action from the background thread</summary>
|
||||
/// <param name="cancellationToken">Token by which execution can be canceled</param>
|
||||
protected abstract void Run(CancellationToken cancellationToken);
|
||||
|
||||
/// <summary>
|
||||
/// Calls the Run() method from the background thread and manages the flags
|
||||
/// </summary>
|
||||
/// <param name="cancellationTokenSource"></param>
|
||||
private void callThreadedExecuteIfNotCancelled(
|
||||
CancellationTokenSource cancellationTokenSource
|
||||
) {
|
||||
lock(this) {
|
||||
if(cancellationTokenSource.Token.IsCancellationRequested) {
|
||||
return;
|
||||
}
|
||||
|
||||
this.isRunning = true;
|
||||
}
|
||||
|
||||
try {
|
||||
Run(cancellationTokenSource.Token);
|
||||
}
|
||||
finally {
|
||||
bool reportBusyChange = false;
|
||||
|
||||
lock(this) {
|
||||
this.isRunning = false;
|
||||
|
||||
// Cancel the current cancellation token because this execution may have
|
||||
// been scheduled multiple times (there's no way for the Run() method to
|
||||
// know if the currently scheduled execution was cancelled, so it is forced
|
||||
// to reschedule on each call - accepting redundant schedules).
|
||||
cancellationTokenSource.Cancel();
|
||||
|
||||
// Pick the next cancellation token source. Normally it is null, but this
|
||||
// is more elegant because we can avoid an while if statement this way :)
|
||||
this.currentCancellationTokenSource = nextCancellationTokenSource;
|
||||
this.nextCancellationTokenSource = null;
|
||||
|
||||
// If Start() was called while we were executing, another execution is required
|
||||
// (because the data may have changed during the call to Start()).
|
||||
if(this.isScheduledAgain) {
|
||||
this.isScheduledAgain = false;
|
||||
scheduleExecution();
|
||||
} else { // We're idle now
|
||||
reportBusyChange = (this.isBusy == true);
|
||||
this.isBusy = false;
|
||||
}
|
||||
}
|
||||
|
||||
if(reportBusyChange) {
|
||||
OnPropertyChanged(nameof(IsBusy));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Schedules one execution of the action</summary>
|
||||
private void scheduleExecution() {
|
||||
//System.Diagnostics.Debug.WriteLine("Scheduling execution");
|
||||
|
||||
ThreadRunner runner = this.externalThreadRunner;
|
||||
if(runner != null) {
|
||||
runner.RunInBackground(
|
||||
this.callRunIfNotCancelledDelegate, this.currentCancellationTokenSource
|
||||
);
|
||||
}
|
||||
|
||||
runner = this.ownThreadRunner;
|
||||
if(runner != null) {
|
||||
runner.RunInBackground(
|
||||
this.callRunIfNotCancelledDelegate, this.currentCancellationTokenSource
|
||||
);
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Reports an error that occurred in the runner's background thread</summary>
|
||||
/// <param name="exception">Exception that the thread has encountered</param>
|
||||
private void reportErrorFromThread(Exception exception) {
|
||||
this.uiContext.Invoke(this.reportErrorDelegate, new object[1] { exception });
|
||||
}
|
||||
|
||||
/// <summary>Finds the application's main window</summary>
|
||||
/// <returns>Main window of the application</returns>
|
||||
private static Form getMainWindow() {
|
||||
IntPtr mainWindowHandle = System.Diagnostics.Process.GetCurrentProcess().MainWindowHandle;
|
||||
|
||||
// We can get two things: a list of all open windows and the handle of
|
||||
// the window that the process has registered as main window. Use the latter
|
||||
// to pick the correct window from the former.
|
||||
FormCollection openForms = Application.OpenForms;
|
||||
int openFormCount = openForms.Count;
|
||||
for(int index = 0; index < openFormCount; ++index) {
|
||||
if(openForms[index].IsHandleCreated) {
|
||||
if(openForms[index].Handle == mainWindowHandle) {
|
||||
return openForms[index];
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// No matching main window found: use the first one in good faith or fail.
|
||||
if(openFormCount > 0) {
|
||||
return openForms[0];
|
||||
} else {
|
||||
return null;
|
||||
}
|
||||
}
|
||||
|
||||
/// <summary>Synchronization context of the thread in which the view runs</summary>
|
||||
private ISynchronizeInvoke uiContext;
|
||||
/// <summary>Delegate for the ReportError() method</summary>
|
||||
private Action<Exception> reportErrorDelegate;
|
||||
/// <summary>Delegate for the callThreadedExecuteIfNotCancelled() method</summary>
|
||||
private Action<CancellationTokenSource> callRunIfNotCancelledDelegate;
|
||||
|
||||
/// <summary>Thread runner on which the action can run its background task</summary>
|
||||
private ThreadedActionThreadRunner ownThreadRunner;
|
||||
/// <summary>
|
||||
/// External thread runner on which the action runs its background task if assigned
|
||||
/// </summary>
|
||||
private ThreadRunner externalThreadRunner;
|
||||
|
||||
/// <summary>Synchronization root for the threaded execute method</summary>
|
||||
private object runningTaskSyncRoot = new object();
|
||||
/// <summary>Used to cancel the currently running task</summary>
|
||||
private CancellationTokenSource currentCancellationTokenSource;
|
||||
/// <summary>Used to cancel the upcoming task if a re-run was scheduled</summary>
|
||||
private CancellationTokenSource nextCancellationTokenSource;
|
||||
/// <summary>Whether the background task is running or waiting to run</summary>
|
||||
private volatile bool isBusy;
|
||||
/// <summary>Whether execution is taking place right now</summary>
|
||||
/// <remarks>
|
||||
/// If this flag is set and the Start() method is called, another run needs to
|
||||
/// be scheduled.
|
||||
/// </remarks>
|
||||
private bool isRunning;
|
||||
/// <summary>Whether run was called while the action was already running</summary>
|
||||
private bool isScheduledAgain;
|
||||
|
||||
}
|
||||
|
||||
} // namespace Nuclex.Windows.Forms.ViewModels
|
|
@ -1,4 +1,26 @@
|
|||
using System;
|
||||
#region CPL License
|
||||
/*
|
||||
Nuclex Framework
|
||||
Copyright (C) 2002-2019 Nuclex Development Labs
|
||||
|
||||
This library is free software; you can redistribute it and/or
|
||||
modify it under the terms of the IBM Common Public License as
|
||||
published by the IBM Corporation; either version 1.0 of the
|
||||
License, or (at your option) any later version.
|
||||
|
||||
This library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
IBM Common Public License for more details.
|
||||
|
||||
You should have received a copy of the IBM Common Public
|
||||
License along with this library
|
||||
*/
|
||||
#endregion
|
||||
|
||||
#if UNITTEST
|
||||
|
||||
using System;
|
||||
|
||||
using NUnit.Framework;
|
||||
|
||||
|
@ -148,3 +170,5 @@ namespace Nuclex.Windows.Forms.ViewModels {
|
|||
}
|
||||
|
||||
} // namespace Nuclex.Windows.Forms.ViewModels
|
||||
|
||||
#endif // UNITTEST
|
||||
|
|
|
@ -1,4 +1,24 @@
|
|||
#if UNITTEST
|
||||
#region CPL License
|
||||
/*
|
||||
Nuclex Framework
|
||||
Copyright (C) 2002-2019 Nuclex Development Labs
|
||||
|
||||
This library is free software; you can redistribute it and/or
|
||||
modify it under the terms of the IBM Common Public License as
|
||||
published by the IBM Corporation; either version 1.0 of the
|
||||
License, or (at your option) any later version.
|
||||
|
||||
This library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
IBM Common Public License for more details.
|
||||
|
||||
You should have received a copy of the IBM Common Public
|
||||
License along with this library
|
||||
*/
|
||||
#endregion
|
||||
|
||||
#if UNITTEST
|
||||
|
||||
using System;
|
||||
using System.ComponentModel;
|
||||
|
@ -135,11 +155,29 @@ namespace Nuclex.Windows.Forms.ViewModels {
|
|||
RunInBackground(() => throw error);
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Assigns the specified value to the same-named property from a background thread
|
||||
/// </summary>
|
||||
/// <param name="value">Value that will be assigned to the same-named property</param>
|
||||
public void AssignValueInBackgroundThread(int value) {
|
||||
RunInBackground(
|
||||
delegate () {
|
||||
this.assignedValue = value;
|
||||
this.finishedGate.Set();
|
||||
}
|
||||
);
|
||||
}
|
||||
|
||||
/// <summary>Last error that was reported by the threaded view model</summary>
|
||||
public Exception ReportedError {
|
||||
get { return this.reportedError; }
|
||||
}
|
||||
|
||||
/// <summary>Value that has been assigned from the background thread</summary>
|
||||
public int AssignedValue {
|
||||
get { return this.assignedValue; }
|
||||
}
|
||||
|
||||
/// <summary>Called when an error occurs in the background thread</summary>
|
||||
/// <param name="exception">Exception that was thrown in the background thread</param>
|
||||
protected override void ReportError(Exception exception) {
|
||||
|
@ -148,16 +186,18 @@ namespace Nuclex.Windows.Forms.ViewModels {
|
|||
}
|
||||
|
||||
/// <summary>Last error that was reported by the threaded view model</summary>
|
||||
private Exception reportedError;
|
||||
private volatile Exception reportedError;
|
||||
/// <summary>Triggered when the </summary>
|
||||
private ManualResetEvent finishedGate;
|
||||
/// <summary>Value that is assigned through the background thread</summary>
|
||||
private volatile int assignedValue;
|
||||
|
||||
}
|
||||
|
||||
#endregion // class TestViewModel
|
||||
|
||||
/// <summary>Verifies that the threaded view model has a default constructor</summary>
|
||||
[Test]
|
||||
[Test, Explicit]
|
||||
public void HasDefaultConstructor() {
|
||||
using(var mainForm = new System.Windows.Forms.Form()) {
|
||||
mainForm.Show();
|
||||
|
@ -201,6 +241,18 @@ namespace Nuclex.Windows.Forms.ViewModels {
|
|||
}
|
||||
}
|
||||
|
||||
/// <summary>
|
||||
/// Verifies that the background thread actually executes and can do work
|
||||
/// </summary>
|
||||
[Test]
|
||||
public void BackgroundThreadExecutesTasks() {
|
||||
using(var viewModel = new TestViewModel(new DummyContext())) {
|
||||
viewModel.AssignValueInBackgroundThread(10042);
|
||||
viewModel.WaitUntilFinished();
|
||||
Assert.AreEqual(10042, viewModel.AssignedValue);
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
} // namespace Nuclex.Windows.Forms.ViewModels
|
||||
|
|
|
@ -196,6 +196,12 @@ namespace Nuclex.Windows.Forms.ViewModels {
|
|||
OnPropertyChanged(nameof(IsBusy));
|
||||
}
|
||||
|
||||
// For the ThreadedAction class - there should be a better way!
|
||||
/// <summary>Thread runner that manages the view model's thread</summary>
|
||||
internal ThreadRunner ThreadRunner {
|
||||
get { return this.threadRunner; }
|
||||
}
|
||||
|
||||
/// <summary>Reports an error that occurred in the runner's background thread</summary>
|
||||
/// <param name="exception">Exception that the thread has encountered</param>
|
||||
private void reportErrorFromThread(Exception exception) {
|
||||
|
|
38
Source/Views/IActiveWindowTracker.cs
Normal file
38
Source/Views/IActiveWindowTracker.cs
Normal file
|
@ -0,0 +1,38 @@
|
|||
#region CPL License
|
||||
/*
|
||||
Nuclex Framework
|
||||
Copyright (C) 2002-2019 Nuclex Development Labs
|
||||
|
||||
This library is free software; you can redistribute it and/or
|
||||
modify it under the terms of the IBM Common Public License as
|
||||
published by the IBM Corporation; either version 1.0 of the
|
||||
License, or (at your option) any later version.
|
||||
|
||||
This library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
IBM Common Public License for more details.
|
||||
|
||||
You should have received a copy of the IBM Common Public
|
||||
License along with this library
|
||||
*/
|
||||
#endregion
|
||||
|
||||
using System;
|
||||
using System.Windows.Forms;
|
||||
|
||||
namespace Nuclex.Windows.Forms {
|
||||
|
||||
/// <summary>Enables consumer to look up the currently active window</summary>
|
||||
public interface IActiveWindowTracker {
|
||||
|
||||
/// <summary>The currently active top-level or modal window</summary>
|
||||
/// <remarks>
|
||||
/// If windows live in multiple threads, the property change notification for
|
||||
/// this property, if supported, might be fired from a different thread.
|
||||
/// </remarks>
|
||||
Form ActiveWindow { get; }
|
||||
|
||||
}
|
||||
|
||||
} // namespace Nuclex.Windows.Forms
|
21
Source/WindowManager.Test.cs
Normal file
21
Source/WindowManager.Test.cs
Normal file
|
@ -0,0 +1,21 @@
|
|||
using System;
|
||||
|
||||
using NUnit.Framework;
|
||||
|
||||
namespace Nuclex.Windows.Forms {
|
||||
|
||||
/// <summary>Unit test for the window manager</summary>
|
||||
[TestFixture]
|
||||
public class WindowManagerTest {
|
||||
|
||||
/// <summary>Verifies that the window manager provides a default constructor</summary>
|
||||
[Test]
|
||||
public void HasDefaultConstructor() {
|
||||
Assert.DoesNotThrow(
|
||||
() => new WindowManager()
|
||||
);
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
} // namespace Nuclex.Windows.Forms
|
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Reference in New Issue
Block a user