//
// Constructors
//
#region Constructors
/// <summary>
/// Creates a Clock object.
/// </summary>
/// <param name="timeline">
/// The Timeline to use as a template.
/// </param>
/// <remarks>
/// The returned Clock doesn't have any children.
/// </remarks>
protected internal Clock(Timeline timeline)
{
#if DEBUG
lock (_debugLockObject)
{
_debugIdentity = ++_nextIdentity;
WeakReference weakRef = new WeakReference(this);
_objectTable[_debugIdentity] = weakRef;
}
#endif // DEBUG
Debug.Assert(timeline != null);
//
// Store a frozen copy of the timeline
//
_timeline = (Timeline)timeline.GetCurrentValueAsFrozen();
// GetCurrentValueAsFrozen will make a clone of the Timeline if it's
// not frozen and will return the Timeline if it is frozen.
// The clone will never have event handlers, while the
// frozen original may. This means we need to copy
// the event handlers from the original timeline onto the clock
// to be consistent.
//
// Copy the event handlers from the original timeline into the clock
//
_eventHandlersStore = timeline.InternalEventHandlersStore;
//
// FXCop fix. Do not call overridables in constructors
// UpdateNeedsTicksWhenActive();
// Set the NeedsTicksWhenActive only if we have someone listening
// to an event.
SetFlag(ClockFlags.NeedsTicksWhenActive, _eventHandlersStore != null);
//
// Cache values that won't change as the clock ticks
//
// Non-root clocks have an unchanging begin time specified by their timelines.
// A root clock will update _beginTime as necessary.
_beginTime = _timeline.BeginTime;
// Cache duration, getting Timeline.Duration and recalculating duration
// each Tick was eating perf, resolve the duration if possible.
_resolvedDuration = _timeline.Duration;
if (_resolvedDuration == Duration.Automatic)
{
// Forever is the default for an automatic duration. We can't
// try to resolve the duration yet because the tree
// may not be fully built, in which case ClockGroups won't
// have their children yet.
_resolvedDuration = Duration.Forever;
}
else
{
HasResolvedDuration = true;
}
_currentDuration = _resolvedDuration;
// Cache speed ratio, for roots this value may be updated if the interactive
// speed ratio changes, but for non-roots this value will remain constant
// throughout the lifetime of the clock.
_appliedSpeedRatio = _timeline.SpeedRatio;
//
// Initialize current state
//
_currentClockState = ClockState.Stopped;
if (_beginTime.HasValue)
{
// We need a tick to bring our state up to date
_nextTickNeededTime = TimeSpan.Zero;
}
// All other data members initialized to zero by default
}
