Ported the ProgressReporter and the TrackingBar to the AsyncProgressBar control to eliminate the very similar code both controls were using to perform thread synchronization

git-svn-id: file:///srv/devel/repo-conversion/nuwi@10 d2e56fa2-650e-0410-a79f-9358c0239efd

Nuclex.Windows.Forms.csproj

@@ -101,6 +101,8 @@
     </Compile>
     <Compile Include="Source\ProgressReporter\ProgressReporterForm.Designer.cs">
       <DependentUpon>ProgressReporterForm.cs</DependentUpon>
+      <XNAUseContentPipeline>false</XNAUseContentPipeline>
+      <Name>ProgressReporterForm.Designer</Name>
     </Compile>
     <Compile Include="Source\TrackingBar\TrackingBar.cs">
       <XNAUseContentPipeline>false</XNAUseContentPipeline>

Source/AsyncProgressBar/AsyncProgressBar.cs

@@ -73,6 +73,7 @@ namespace Nuclex.Windows.Forms {
     /// <summary>Synchronously updates the value visualized in the progress bar</summary>
     private void updateProgress() {
 
+      // Cache these to shorten the code that follows :)
       int minimum = base.Minimum;
       int maximum = base.Maximum;
 

Source/ProgressReporter/ProgressReporterForm.Designer.cs

@@ -25,7 +25,7 @@ namespace Nuclex.Windows.Forms {
     private void InitializeComponent() {
       this.components = new System.ComponentModel.Container();
       this.cancelButton = new System.Windows.Forms.Button();
-      this.progressBar = new System.Windows.Forms.ProgressBar();
+      this.progressBar = new Nuclex.Windows.Forms.AsyncProgressBar();
       this.statusLabel = new System.Windows.Forms.Label();
       this.controlCreationTimer = new System.Windows.Forms.Timer(this.components);
       this.SuspendLayout();
@@ -92,7 +92,7 @@ namespace Nuclex.Windows.Forms {
     #endregion
 
     private System.Windows.Forms.Button cancelButton;
-    private System.Windows.Forms.ProgressBar progressBar;
+    private Nuclex.Windows.Forms.AsyncProgressBar progressBar;
     private System.Windows.Forms.Label statusLabel;
     private System.Windows.Forms.Timer controlCreationTimer;
   }

Source/ProgressReporter/ProgressReporterForm.cs

@@ -22,7 +22,6 @@ namespace Nuclex.Windows.Forms {
     internal ProgressReporterForm() {
       InitializeComponent();
 
-      this.updateProgressDelegate = new MethodInvoker(updateProgress);
       this.asyncEndedDelegate = new EventHandler(asyncEnded);
       this.asyncProgressUpdatedDelegate = new EventHandler<ProgressUpdateEventArgs>(
         asyncProgressUpdated
@@ -112,8 +111,7 @@ namespace Nuclex.Windows.Forms {
 
       // If the new state is 2, the form was ready to close (since the state
       // is incremented once when the form becomes ready to be closed)
-      int newState = Interlocked.Increment(ref this.state);
+      if(Interlocked.Increment(ref this.state) == 2) {
-      if(newState == 2) {
 
         // Close the dialog. Ensure the Close() method is invoked from the
         // same thread the dialog was created in.
@@ -132,53 +130,7 @@ namespace Nuclex.Windows.Forms {
     ///   Contains the new progress achieved by the progression
     /// </param>
     private void asyncProgressUpdated(object sender, ProgressUpdateEventArgs arguments) {
-
+      this.progressBar.AsyncSetValue(arguments.Progress);
-      // Set the new progress without any synchronization
-      this.currentProgress = arguments.Progress;
-
-      // Another use of the double-checked locking idiom, here we're trying to optimize
-      // away the lock in case some "trigger-happy" progressions send way more
-      // progress updates than the poor control can process :)
-      if(!this.progressUpdatePending) {
-        lock(this) {
-          if(!this.progressUpdatePending) {
-            this.progressUpdatePending = true;
-            this.progressUpdateAsyncResult = BeginInvoke(this.updateProgressDelegate);
-          }
-        } // lock
-      }
-
-    }
-
-    /// <summary>Synchronously updates the value visualized in the progress bar</summary>
-    private void updateProgress() {
-      lock(this) {
-
-        // Reset the update flag so incoming updates will cause the control to
-        // update itself another time.
-        this.progressUpdatePending = false;
-        EndInvoke(this.progressUpdateAsyncResult);
-
-        // Until the first progress event is received, the progress reporter shows
-        // a marquee bar to entertain the user even when no progress reports are
-        // being made at all.
-        if(this.progressBar.Style == ProgressBarStyle.Marquee)
-          this.progressBar.Style = ProgressBarStyle.Blocks;
-
-        // Transform the progress into an integer in the range of the progress bar's
-        // min and max values (these should normally be set to 0 and 100).
-        int min = this.progressBar.Minimum;
-        int max = this.progressBar.Maximum;
-        int progress = (int)(this.currentProgress * (max - min)) + min;
-
-        // Update the control
-        this.progressBar.Value = Math.Min(Math.Max(progress, min), max);
-
-        // Assigning the value sends PBM_SETPOS to the control which,
-        // according to MSDN, already causes a redraw!
-        //base.Invalidate();
-
-      } // lock
     }
 
     /// <summary>
@@ -196,8 +148,7 @@ namespace Nuclex.Windows.Forms {
 
       // If the new state is 2, then the form was requested to close before it had
       // been fully constructed, so we should close it now!
-      int newState = System.Threading.Interlocked.Increment(ref this.state);
+      if(Interlocked.Increment(ref this.state) == 2)
-      if(newState == 2)
         Close();
 
     }
@@ -228,14 +179,6 @@ namespace Nuclex.Windows.Forms {
     private EventHandler asyncEndedDelegate;
     /// <summary>Delegate for the asyncProgressUpdated() method</summary>
     private EventHandler<ProgressUpdateEventArgs> asyncProgressUpdatedDelegate;
-    /// <summary>Delegate for the progress update method</summary>
-    private MethodInvoker updateProgressDelegate;
-    /// <summary>Whether an update of the control state is pending</summary>
-    private volatile bool progressUpdatePending;
-    /// <summary>Async result for the invoked control state update method</summary>
-    private volatile IAsyncResult progressUpdateAsyncResult;
-    /// <summary>Most recently reported progress of the tracker</summary>
-    private volatile float currentProgress;
     /// <summary>Whether the form can be closed and should be closed</summary>
     /// <remarks>
     ///   0: Nothing happened yet

Source/TrackingBar/TrackingBar.cs

@@ -32,7 +32,7 @@ using Nuclex.Support.Tracking;
 namespace Nuclex.Windows.Forms {
 
   /// <summary>Progress bar for tracking the progress of background operations</summary>
-  public partial class TrackingBar : ProgressBar {
+  public partial class TrackingBar : AsyncProgressBar {
 
     /// <summary>Initializes a new tracking bar</summary>
     public TrackingBar() {
@@ -42,21 +42,20 @@ namespace Nuclex.Windows.Forms {
       this.isIdle = true;
       base.Visible = false;
 
+      // Create the tracker and attach ourselfes to its events
+      this.tracker = new ProgressionTracker();
+      this.tracker.AsyncIdleStateChanged += this.asyncIdleStateChangedDelegate;
+      this.tracker.AsyncProgressUpdated += this.asyncProgressUpdateDelegate;
+
       // Initialize the delegates we use to update the control's state and those
       // we use to register ourselfes to the tracker's events
       this.updateIdleStateDelegate = new MethodInvoker(updateIdleState);
-      this.updateProgressDelegate = new MethodInvoker(updateProgress);
       this.asyncIdleStateChangedDelegate = new EventHandler<IdleStateEventArgs>(
         asyncIdleStateChanged
       );
       this.asyncProgressUpdateDelegate = new EventHandler<ProgressUpdateEventArgs>(
         asyncProgressUpdated
       );
-
-      // Create the tracker and attach ourselfes to its events
-      this.tracker = new ProgressionTracker();
-      this.tracker.AsyncIdleStateChanged += this.asyncIdleStateChangedDelegate;
-      this.tracker.AsyncProgressUpdated += this.asyncProgressUpdateDelegate;
     }
 
     /// <summary>Tracks the specified progression in the tracking bar</summary>
@@ -86,22 +85,7 @@ namespace Nuclex.Windows.Forms {
     private void asyncProgressUpdated(
       object sender, ProgressUpdateEventArgs arguments
     ) {
-
+      AsyncSetValue(arguments.Progress);
-      // Set the new progress without any synchronization
-      this.currentProgress = arguments.Progress;
-
-      // Another use of the double-checked locking idiom, here we're trying to optimize
-      // away the lock in case some "trigger-happy" progressions send way more
-      // progress updates than the poor control can process :)
-      if(!this.progressUpdatePending) {
-        lock(this) {
-          if(!this.progressUpdatePending) {
-            this.progressUpdatePending = true;
-            this.progressUpdateAsyncResult = BeginInvoke(this.updateProgressDelegate);
-          }
-        } // lock
-      }
-
     }
     
     /// <summary>Called when the tracker becomes enters of leaves the idle state</summary>
@@ -113,58 +97,30 @@ namespace Nuclex.Windows.Forms {
       // lost because otherwise, the progress bar might stay on-screen when in fact,
       // the background operation has already finished and nothing is happening anymore.
       this.isIdle = arguments.Idle;
+
+      // Update the bar's idle state
+      if(InvokeRequired)
         Invoke(this.updateIdleStateDelegate);
+      else
+        updateIdleState();
 
     }
 
-    /// <summary>Synchronously updates the value visualized in the progress bar</summary>
-    private void updateProgress() {
-      lock(this) {
-
-        // Reset the update flag so incoming updates will cause the control to
-        // update itself another time.
-        this.progressUpdatePending = false;
-        EndInvoke(this.progressUpdateAsyncResult);
-
-        // Transform the progress into an integer in the range of the progress bar's
-        // min and max values (these should normally be set to 0 and 100).
-        int min = base.Minimum;
-        int max = base.Maximum;
-        int progress = (int)(this.currentProgress * (max - min)) + min;
-
-        // Update the control
-        base.Value = progress;
-
-        // Assigning the value sends PBM_SETPOS to the control which,
-        // according to MSDN, already causes a redraw!
-        //base.Invalidate();
-
-      } // lock
-    }
-
     /// <summary>
     ///   Updates the idle state of the progress bar
     ///   (controls whether the progress bar is shown or invisible)
     /// </summary>
     private void updateIdleState() {
 
+      // Only show the progress bar when something is happening
       base.Visible = !this.isIdle;
 
     }
 
-    /// <summary>Whether an update of the control state is pending</summary>
-    private volatile bool progressUpdatePending;
-    /// <summary>Async result for the invoked control state update method</summary>
-    private volatile IAsyncResult progressUpdateAsyncResult;
     /// <summary>Whether the progress bar is in the idle state</summary>
     private volatile bool isIdle;
-    /// <summary>Most recently reported progress of the tracker</summary>
-    private volatile float currentProgress;
-
     /// <summary>Tracker used to sum and update the total progress</summary>
     private ProgressionTracker tracker;
-    /// <summary>Delegate for the progress update method</summary>
-    private MethodInvoker updateProgressDelegate;
     /// <summary>Delegate for the idle state update method</summary>
     private MethodInvoker updateIdleStateDelegate;
     /// <summary>Delegate for the OnAsyncProgressionEnded method</summary>