/// <summary>
/// Enables progress polling.
/// Use <see cref="CurrentProgress"/> to retrieve the task's current progress.
/// Returns the current progress task, so that methods may be chained.
/// </summary>
public ProgressTask EnablePolling(int maximumDepth)
{
this.pollingEnabled = true;
this.currentProgressAccessed = true;
this.currentProgress = new ProgressChangedInfo(new ProgressInfo(0f, null, null), null);
this.maximumDepth = (ProgressDepth)maximumDepth;
return(this);
}
/// <summary>
/// Calculates the current progress,
/// and invokes the callback for the
/// current task and all parent tasks.
/// </summary>
private void OnProgressChanged(object currentStepArg)
{
// First, an optimization:
// we might not need to calculate progress at all,
// if no one is listening:
ProgressDepth depth = 0;
var task = this;
while (true)
{
// Determine if we've reached the bottom of the stack or the maximum depth:
if (task == null || task.maximumDepth < depth)
{
// No one's listening this deep!
// Skip calculations.
return;
}
// Check for a callback:
if (task.progressChangedCallback != null)
{
break;
}
// Check for polling:
if (task.pollingEnabled)
{
if (task.currentProgressAccessed || (int)depth < task.currentProgress.CurrentDepth)
{
// Polling is enabled and is ready for a new CurrentProgress.
break;
}
}
// Traverse the progress stack:
depth++;
task = task.parent;
}
depth = 0;
task = this;
var taskProgress = 0.0f;
var allProgress = new Stack <ProgressInfo>();
while (true)
{
// Calculate the task's progress:
if (task.isEnded) // 100%!
{
taskProgress = 1.0f;
}
else
{
taskProgress = task.calculator.CalculateProgress(taskProgress);
}
allProgress.Push(new ProgressInfo(taskProgress, task.taskKey, task.taskArg));
// Raise events or update Polling:
ProgressChangedInfo progressChangedInfo = null;
// Raise the event if necessary:
if (task.progressChangedCallback != null)
{
progressChangedInfo = new ProgressChangedInfo(allProgress, currentStepArg);
task.progressChangedCallback(progressChangedInfo);
}
// Update the CurrentProgress so that it can be used for polling.
if (task.pollingEnabled)
{
// If the current CurrentProgress hasn't been accessed,
// then we will only update if the new item is higher priority (lower depth):
if (task.currentProgressAccessed || (int)depth < task.currentProgress.CurrentDepth)
{
if (progressChangedInfo == null)
{
progressChangedInfo = new ProgressChangedInfo(allProgress, currentStepArg);
}
task.currentProgressAccessed = false;
task.currentProgress = progressChangedInfo;
}
}
// Traverse the progress stack:
depth++;
task = task.parent;
// Determine if we've reached the bottom of the stack or the maximum depth:
if (task == null || task.maximumDepth < depth)
{
break;
}
}
}
