nuclex-shared-dotnet/Nuclex.Windows.Forms
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages 1 Wiki Activity

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

Browse source 
git-svn-id: file:///srv/devel/repo-conversion/nuwi@10 d2e56fa2-650e-0410-a79f-9358c0239efd
This commit is contained in:
Markus Ewald 2007-07-22 21:55:35 +00:00
parent 4734c35111
commit 4261d9b449
5 changed files with 21 additions and 119 deletions
Download patch file Download diff file Expand all files Collapse all files

70
Source/TrackingBar/TrackingBar.cs
View file

@ -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
) {
// 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
}
AsyncSetValue(arguments.Progress);
}
/// <summary>Called when the tracker becomes enters of leaves the idle state</summary>
@ -113,33 +97,13 @@ 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;
Invoke(this.updateIdleStateDelegate);
}
// 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>
@ -148,23 +112,15 @@ namespace Nuclex.Windows.Forms {
/// </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>