/// <summary>
/// Implementation of <see cref="FilterManipulation"/> that forces the center of mass of the
/// manipulation target to remain inside its container.
/// </summary>
/// <param name="sender"></param>
/// <param name="args"></param>
public static void ClampCenterOfMass(object sender, FilterManipulationEventArgs args)
{
var inputProcessor = sender as InputProcessor;
var target = inputProcessor.Target;
var container = inputProcessor.Reference;
// Get the bounding box and the center of mass of the manipulation target,
// expressed in the coordinate system of its container
var rect = target.RenderTransform.TransformBounds(
new Windows.Foundation.Rect(0, 0, target.ActualWidth, target.ActualHeight));
var centerOfMass = new Windows.Foundation.Point
{
X = rect.Left + (rect.Width / 2),
Y = rect.Top + (rect.Height / 2)
};
// Apply delta transform to the center of mass
var transform = new Windows.UI.Xaml.Media.CompositeTransform
{
CenterX = args.Pivot.X,
CenterY = args.Pivot.Y,
Rotation = args.Delta.Rotation,
ScaleX = args.Delta.Scale,
ScaleY = args.Delta.Scale,
TranslateX = args.Delta.Translation.X,
TranslateY = args.Delta.Translation.Y
};
var transformedCenterOfMass = transform.TransformPoint(centerOfMass);
// Reset the transformation if the transformed center of mass falls outside the container
if (transformedCenterOfMass.X < 0 || transformedCenterOfMass.X > container.ActualWidth ||
transformedCenterOfMass.Y < 0 || transformedCenterOfMass.Y > container.ActualHeight)
{
args.Delta = new Windows.UI.Input.ManipulationDelta
{
Rotation = 0F,
Scale = 1F,
Translation = new Windows.Foundation.Point(0, 0)
};
}
}
public void ResetManipulation()
{
// Reset previous transform to the initial transform of the element
this._previousTransform = new Windows.UI.Xaml.Media.MatrixTransform()
{
Matrix = this._initialTransform.Matrix
};
// Recreate delta transfrom. This way it is initalized to the identity transform.
this._deltaTransform = new Windows.UI.Xaml.Media.CompositeTransform();
// The actual transform is obtained as the composition of the delta transform
// with the previous transform
this._transform = new Windows.UI.Xaml.Media.TransformGroup()
{
Children = { this._previousTransform, this._deltaTransform }
};
// Set the element's transform
this._target.RenderTransform = this._transform;
}
/// <summary>
/// Implementation of <see cref="FilterManipulation"/> that forces the center of mass of the
/// manipulation target to remain inside its container.
/// </summary>
/// <param name="sender"></param>
/// <param name="args"></param>
public static void ClampCenterOfMass(object sender, Manipulations.FilterManipulationEventArgs args)
{
var inputProcessor = sender as Manipulations.InputProcessor;
var target = inputProcessor.Target;
var container = inputProcessor.Reference;
// Get the bounding box and the center of mass of the manipulation target,
// expressed in the coordinate system of its container
var rect = target.RenderTransform.TransformBounds(
new Windows.Foundation.Rect(0, 0, target.ActualWidth, target.ActualHeight));
var centerOfMass = new Windows.Foundation.Point
{
X = rect.Left + (rect.Width / 2),
Y = rect.Top + (rect.Height / 2)
};
// Apply delta transform to the center of mass
var transform = new Windows.UI.Xaml.Media.CompositeTransform
{
CenterX = args.Pivot.X,
CenterY = args.Pivot.Y,
Rotation = args.Delta.Rotation,
ScaleX = args.Delta.Scale,
ScaleY = args.Delta.Scale,
TranslateX = args.Delta.Translation.X,
TranslateY = args.Delta.Translation.Y
};
var transformedCenterOfMass = transform.TransformPoint(centerOfMass);
// Reset the transformation if the transformed center of mass falls outside the container
if (transformedCenterOfMass.X < 0 || transformedCenterOfMass.X > container.ActualWidth ||
transformedCenterOfMass.Y < 0 || transformedCenterOfMass.Y > container.ActualHeight)
{
args.Delta = new Windows.UI.Input.ManipulationDelta
{
Rotation = 0F,
Scale = 1F,
Translation = new Windows.Foundation.Point(0, 0)
};
}
}
public void ResetManipulation()
{
// Reset previous transform to the initial transform of the element
this._previousTransform = new Windows.UI.Xaml.Media.MatrixTransform()
{
Matrix = this._initialTransform.Matrix
};
this._deltaTransform = new Windows.UI.Xaml.Media.CompositeTransform();
this._transform = new Windows.UI.Xaml.Media.TransformGroup()
{
Children = { this._previousTransform, this._deltaTransform }
};
// Set the element's transform
this._target.RenderTransform = this._transform;
}
public void ResetManipulation()
{
// Reset previous transform to the initial transform of the element
this._previousTransform = new Windows.UI.Xaml.Media.MatrixTransform()
{
Matrix = this._initialTransform.Matrix
};
// Recreate delta transfrom. This way it is initalized to the identity transform.
this._deltaTransform = new Windows.UI.Xaml.Media.CompositeTransform();
// The actual transform is obtained as the composition of the delta transform
// with the previous transform
this._transform = new Windows.UI.Xaml.Media.TransformGroup()
{
Children = { this._previousTransform, this._deltaTransform }
};
// Set the element's transform
this._target.RenderTransform = this._transform;
}
public static void ClampCenterOfMass(object sender, FilterManipulationEventArgs args)
{
var inputProcessor = sender as InputProcessor;
var target = inputProcessor.Target;
var container = inputProcessor.Reference;
var rect = target.RenderTransform.TransformBounds(
new Windows.Foundation.Rect(0, 0, target.ActualWidth, target.ActualHeight));
var centerOfMass = new Windows.Foundation.Point
{
X = rect.Left + (rect.Width / 2),
Y = rect.Top + (rect.Height / 2)
};
var transform = new Windows.UI.Xaml.Media.CompositeTransform
{
CenterX = args.Pivot.X,
CenterY = args.Pivot.Y,
Rotation = args.Delta.Rotation,
ScaleX = args.Delta.Scale,
ScaleY = args.Delta.Scale,
TranslateX = args.Delta.Translation.X,
TranslateY = args.Delta.Translation.Y
};
var transformedCenterOfMass = transform.TransformPoint(centerOfMass);
if (transformedCenterOfMass.X < 0 || transformedCenterOfMass.X > container.ActualWidth ||
transformedCenterOfMass.Y < 0 || transformedCenterOfMass.Y > container.ActualHeight)
{
args.Delta = new Windows.UI.Input.ManipulationDelta
{
Rotation = 0F,
Scale = 1F,
Translation = new Windows.Foundation.Point(0, 0)
};
}
}
