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>
/// 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);
}