/// <summary>
/// Adds the child to the FluidElements collection and initializes its RenderTransform.
/// </summary>
/// <param name="child">UIElement</param>
private void AddChildToFluidElements(UIElement child)
{
// Add the child to the FluidElements collection
FluidElements.Add(child);
// Initialize its RenderTransform
child.RenderTransform = layoutManager.CreateTransform(-ItemWidth, -ItemHeight, NORMAL_SCALE, NORMAL_SCALE);
}
/// <summary>
/// Intializes the arrangement of the children
/// </summary>
private void InitializeArrange()
{
foreach (UIElement child in FluidElements)
{
// Get the child's index in the FluidElements
int index = FluidElements.IndexOf(child);
// Get the initial location of the child
Point pos = layoutManager.GetInitialLocationOfChild(index);
// Initialize the appropriate Render Transform for the child
child.RenderTransform = layoutManager.CreateTransform(pos.X, pos.Y, NORMAL_SCALE, NORMAL_SCALE);
}
}
/// <summary>
/// Moves the dragElement to the new Index
/// </summary>
/// <param name="newIndex">Index of the new location</param>
/// <returns>True-if dragElement was moved otherwise False</returns>
private bool UpdateDragElementIndex(int newIndex)
{
// Check if the dragElement is being moved to its current place
// If yes, then no need to proceed further. (Improves efficiency!)
int dragCellIndex = FluidElements.IndexOf(dragElement);
if (dragCellIndex == newIndex)
{
return(false);
}
FluidElements.RemoveAt(dragCellIndex);
FluidElements.Insert(newIndex, dragElement);
return(true);
}
private void ItemsSourceCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
if (e.OldItems != null)
{
foreach (var item in e.OldItems)
{
FluidElements.Remove((UIElement)item);
}
}
if (e.NewItems != null)
{
foreach (var item in e.NewItems)
{
// Check if the child is already added to the FluidElements collection
if (!FluidElements.Contains((UIElement)item))
{
AddChildToFluidElements((UIElement)item);
}
}
}
}
/// <summary>
/// Removes all the children from the FluidWrapPanel
/// </summary>
private void ClearItemsSource()
{
FluidElements.Clear();
Children.Clear();
}
/// <summary>
/// Iterates through all the fluid elements and animate their
/// movement to their new location.
/// </summary>
private void UpdateFluidLayout(bool showEasing = true)
{
// Iterate through all the fluid elements and animate their
// movement to their new location.
var validElement = FluidElements.Where(o => o != null && o.Visibility == Visibility.Visible).ToList();
for (int index = 0; index < validElement.Count; index++)
{
UIElement element = validElement[index];
//if (element == null||element.Visibility==Visibility.Collapsed)
// continue;
// If an child is currently being dragged, then no need to animate it
if (dragElement != null && index == validElement.IndexOf(dragElement))
{
continue;
}
element.Arrange(new Rect(0, 0, element.DesiredSize.Width,
element.DesiredSize.Height));
// Get the cell position of the current index
Point pos = layoutManager.GetPointFromIndex(index);
Storyboard transition;
// Is the child being animated the same as the child which was last dragged?
if (element == lastDragElement)
{
if (!showEasing)
{
// Create the Storyboard for the transition
transition = layoutManager.CreateTransition(element, pos, FIRST_TIME_ANIMATION_DURATION, null);
}
else
{
// Is easing function specified for the animation?
TimeSpan duration = (DragEasing != null) ? DEFAULT_ANIMATION_TIME_WITH_EASING : DEFAULT_ANIMATION_TIME_WITHOUT_EASING;
// Create the Storyboard for the transition
transition = layoutManager.CreateTransition(element, pos, duration, DragEasing);
}
// When the user releases the drag child, it's Z-Index is set to 1 so that
// during the animation it does not go below other elements.
// After the animation has completed set its Z-Index to 0
transition.Completed += (s, e) =>
{
if (lastDragElement != null)
{
lastDragElement.SetValue(Canvas.ZIndexProperty, 0);
lastDragElement = null;
}
};
}
else // It is a non-dragElement
{
if (!showEasing)
{
// Create the Storyboard for the transition
transition = layoutManager.CreateTransition(element, pos, FIRST_TIME_ANIMATION_DURATION, null);
}
else
{
// Is easing function specified for the animation?
TimeSpan duration = (ElementEasing != null) ? DEFAULT_ANIMATION_TIME_WITH_EASING : DEFAULT_ANIMATION_TIME_WITHOUT_EASING;
// Create the Storyboard for the transition
transition = layoutManager.CreateTransition(element, pos, duration, ElementEasing);
}
}
// Start the animation
transition.Begin();
}
}
/// <summary>
/// Override for the Measure Layout Phase
/// </summary>
/// <param name="availableSize">Available Size</param>
/// <returns>Size required by the panel</returns>
protected override Size MeasureOverride(Size availableSize)
{
Size availableItemSize = new Size(Double.PositiveInfinity, Double.PositiveInfinity);
double rowWidth = 0.0;
double maxRowHeight = 0.0;
double colHeight = 0.0;
double maxColWidth = 0.0;
double totalColumnWidth = 0.0;
double totalRowHeight = 0.0;
// Iterate through all the UIElements in the Children collection
for (int i = 0; i < InternalChildren.Count; i++)
{
UIElement child = InternalChildren[i];
if (child != null)
{
// Ask the child how much size it needs
child.Measure(availableItemSize);
//Check if the child is already added to the FluidElements collection
if (!FluidElements.Contains(child))
{
AddChildToFluidElements(child);
}
if (this.Orientation == Orientation.Horizontal)
{
// Will the child fit in the current row?
//if (rowWidth + child.DesiredSize.Width > availableSize.Width)
if (rowWidth + this.ItemWidth > availableSize.Width)
{
// Wrap to next row
totalRowHeight += maxRowHeight;
// Is the current row width greater than the previous row widths
if (rowWidth > totalColumnWidth)
{
totalColumnWidth = rowWidth;
}
rowWidth = 0.0;
maxRowHeight = 0.0;
}
//rowWidth += child.DesiredSize.Width;
rowWidth += this.ItemWidth;
//if (child.DesiredSize.Height > maxRowHeight)
// maxRowHeight = child.DesiredSize.Height;
if (this.ItemHeight > maxRowHeight)
{
maxRowHeight = this.ItemHeight;
}
}
else // Vertical Orientation
{
// Will the child fit in the current column?
//if (colHeight + child.DesiredSize.Height > availableSize.Height)
if (colHeight + this.ItemHeight > availableSize.Height)
{
// Wrap to next column
totalColumnWidth += maxColWidth;
// Is the current column height greater than the previous column heights
if (colHeight > totalRowHeight)
{
totalRowHeight = colHeight;
}
colHeight = 0.0;
maxColWidth = 0.0;
}
//colHeight += child.DesiredSize.Height;
colHeight += this.ItemHeight;
//if (child.DesiredSize.Width > maxColWidth)
// maxColWidth = child.DesiredSize.Width;
if (this.ItemWidth > maxColWidth)
{
maxColWidth = this.ItemWidth;
}
}
}
}
List <UIElement> dirtyElements = new List <UIElement>();
foreach (var element in FluidElements)
{
if (!InternalChildren.Contains(element))
{
dirtyElements.Add(element);
}
}
foreach (var item in dirtyElements)
{
FluidElements.Remove(item);
}
if (this.Orientation == Orientation.Horizontal)
{
// Add the height of the last row
totalRowHeight += maxRowHeight;
// If there is only one row, take its width as the total width
if (totalColumnWidth == 0.0)
{
totalColumnWidth = rowWidth;
}
}
else
{
// Add the width of the last column
totalColumnWidth += maxColWidth;
// If there is only one column, take its height as the total height
if (totalRowHeight == 0.0)
{
totalRowHeight = colHeight;
}
}
Size resultSize = new Size(totalColumnWidth, totalRowHeight);
return(resultSize);
}
