private void m_listener_rendering(object sender, EventArgs e)
{
if (this.Child != m_zapPanel)
{
m_zapPanel = (ZapPanel)this.Child;
m_zapPanel.RenderTransform = m_traslateTransform;
}
if (m_zapPanel != null)
{
int actualTargetIndex = Math.Max(0, Math.Min(m_zapPanel.Children.Count - 1, TargetIndex));
double targetPercentOffset = -actualTargetIndex / (double)m_zapPanel.Children.Count;
targetPercentOffset = double.IsNaN(targetPercentOffset) ? 0 : targetPercentOffset;
bool stopListening = !WpfUtil.Animate(
m_percentOffset, m_velocity, targetPercentOffset,
.05, .3, .1, c_diff, c_diff,
out m_percentOffset, out m_velocity);
double targetPixelOffset = m_percentOffset * (this.RenderSize.Width * m_zapPanel.Children.Count);
m_traslateTransform.X = targetPixelOffset;
if (stopListening)
{
m_listener.StopListening();
}
}
}
//TODO: be smart about item changes...make sure the control doesn't jump around
//TODO: be smart about wiring/unwiring this callback. Expensive!!
private void CompositionTarget_Rendering(object sender, EventArgs e)
{
if (this.Child != _zapPanel)
{
_zapPanel = this.Child as ZapPanel;
_zapPanel.RenderTransform = _traslateTransform;
}
if (_zapPanel != null)
{
int actualTargetIndex = Math.Max(0, Math.Min(_zapPanel.Children.Count - 1, TargetIndex));
double targetPercentOffset = -actualTargetIndex / (double)_zapPanel.Children.Count;
double currentPercent = _percentOffset;
double deltaPercent = targetPercentOffset - currentPercent;
if (!double.IsNaN(deltaPercent) && !double.IsInfinity(deltaPercent))
{
_velocity *= .9;
_velocity += deltaPercent * .01;
if (Math.Abs(_velocity) > DIFF || Math.Abs(deltaPercent) > DIFF)
{
_percentOffset += _velocity;
}
else
{
_percentOffset = targetPercentOffset;
_velocity = 0;
}
}
double targetPixelOffset = _percentOffset * (this.RenderSize.Width * _zapPanel.Children.Count);
_traslateTransform.X = targetPixelOffset;
}
}
