protected virtual void RaiseDragDelta(DragDeltaGestureEventArgs e)
{
var handler = DragDelta;
if (handler != null)
{
handler(this, e);
}
}
private void OnDragDelta(object sender, DragDeltaGestureEventArgs e)
{
if (!IsEnabled)
{
return;
}
RaiseDragDelta(e);
//if (CurrentScaleX == 1.0) return;
//DebugText.Text = string.Format("DragDelta X={0} Y={1} Direction={2}", e.HorizontalChange, e.VerticalChange, e.Direction);
// Translation is done as the last operation, so no need to move the operation up in composition order
var img = sender as FrameworkElement;
if (img == null)
{
return;
}
var transform = img.RenderTransform as CompositeTransform;
if (transform == null)
{
return;
}
if (!CanZoom)
{
return;
}
var translate = new CompositeTransform
{
TranslateX = e.HorizontalChange,
TranslateY = e.VerticalChange
};
ConstrainToParentBounds(img, translate);
var t = ComposeScaleTranslate(transform, translate);
img.RenderTransform = t;
if (DebugText != null)
{
DebugText.Text = string.Format("Scale={0}x{1}\nCenter={2}x{3}\nTranslate={4}x{5}", t.ScaleX, t.ScaleY, t.CenterX, t.CenterY, t.TranslateX, t.TranslateY);
}
}
private void OnDragDelta(object sender, DragDeltaGestureEventArgs e)
{
if (!IsEnabled)
{
return;
}
_lastDragDeltaEventArgs = e;
RaiseDragDelta(e);
//if (CurrentScaleX == 1.0) return;
//DebugText.Text = string.Format("DragDelta X={0} Y={1} Direction={2}", e.HorizontalChange, e.VerticalChange, e.Direction);
// Translation is done as the last operation, so no need to move the operation up in composition order
var img = sender as FrameworkElement;
if (img == null)
{
return;
}
var transform = img.RenderTransform as CompositeTransform;
if (transform == null)
{
return;
}
CompositeTransform translate = null;
if (CurrentScaleX == 1.0)
{
if (SuppressDrag)
{
return;
}
if (_direction == Orientation.Vertical)
{
translate = new CompositeTransform
{
TranslateX = 0,
TranslateY = e.VerticalChange
};
if (BackgroundPanel != null)
{
var rootFrameHeight = ((PhoneApplicationFrame)Application.Current.RootVisual).ActualHeight;
var deltaY = Math.Abs(translate.TranslateY + translate.ScaleY * transform.TranslateY + (translate.ScaleY - 1) * (transform.CenterY - translate.CenterY));
var opacity = (rootFrameHeight - deltaY) / rootFrameHeight;
var backgroundBrush = (SolidColorBrush)BackgroundPanel.Background;
var backgroundColor = backgroundBrush.Color;
backgroundColor.A = (byte)(opacity * byte.MaxValue);
BackgroundPanel.Opacity = opacity;
//BackgroundPanel.Background = new SolidColorBrush(backgroundColor);
}
img.RenderTransform = ComposeScaleTranslate(transform, translate);
}
else if (_direction == Orientation.Horizontal)
{
//translate = new CompositeTransform
//{
// TranslateX = e.HorizontalChange,
// TranslateY = 0
//};
//img.RenderTransform = ComposeScaleTranslate(transform, translate);
}
}
else
{
if (!CanZoom)
{
return;
}
translate = new CompositeTransform
{
TranslateX = e.HorizontalChange,
TranslateY = e.VerticalChange
};
ConstrainToParentBounds(img, translate);
img.RenderTransform = ComposeScaleTranslate(transform, translate);
}
}
