private void SetSize(
ILayoutable element,
double layoutItemWidth,
double LayoutItemHeight,
Size availableSize,
UniformGridLayoutItemsStretch stretch,
Orientation orientation,
double minRowSpacing,
double minColumnSpacing)
{
EffectiveItemWidth = (double.IsNaN(layoutItemWidth) ? element.DesiredSize.Width : layoutItemWidth);
EffectiveItemHeight = (double.IsNaN(LayoutItemHeight) ? element.DesiredSize.Height : LayoutItemHeight);
var availableSizeMinor = orientation == Orientation.Horizontal ? availableSize.Width : availableSize.Height;
var minorItemSpacing = orientation == Orientation.Vertical ? minRowSpacing : minColumnSpacing;
var itemSizeMinor = orientation == Orientation.Horizontal ? EffectiveItemWidth : EffectiveItemHeight;
itemSizeMinor += minorItemSpacing;
var numItemsPerColumn = (int)(Math.Max(1.0, availableSizeMinor / itemSizeMinor));
var remainingSpace = ((int)availableSizeMinor) % ((int)itemSizeMinor);
var extraMinorPixelsForEachItem = remainingSpace / numItemsPerColumn;
if (stretch == UniformGridLayoutItemsStretch.Fill)
{
if (orientation == Orientation.Horizontal)
{
EffectiveItemWidth += extraMinorPixelsForEachItem;
}
else
{
EffectiveItemHeight += extraMinorPixelsForEachItem;
}
}
else if (stretch == UniformGridLayoutItemsStretch.Uniform)
{
var itemSizeMajor = orientation == Orientation.Horizontal ? EffectiveItemHeight : EffectiveItemWidth;
var extraMajorPixelsForEachItem = itemSizeMajor * (extraMinorPixelsForEachItem / itemSizeMinor);
if (orientation == Orientation.Horizontal)
{
EffectiveItemWidth += extraMinorPixelsForEachItem;
EffectiveItemHeight += extraMajorPixelsForEachItem;
}
else
{
EffectiveItemHeight += extraMinorPixelsForEachItem;
EffectiveItemWidth += extraMajorPixelsForEachItem;
}
}
}
internal void EnsureElementSize(
Size availableSize,
VirtualizingLayoutContext context,
double layoutItemWidth,
double layoutItemHeight,
UniformGridLayoutItemsStretch stretch,
Orientation orientation,
double minRowSpacing,
double minColumnSpacing,
int maxItemsPerLine)
{
if (maxItemsPerLine == 0)
{
maxItemsPerLine = 1;
}
if (context.ItemCount > 0)
{
// If the first element is realized we don't need to cache it or to get it from the context
var realizedElement = FlowAlgorithm.GetElementIfRealized(0);
if (realizedElement != null)
{
realizedElement.Measure(availableSize);
SetSize(realizedElement, layoutItemWidth, layoutItemHeight, availableSize, stretch, orientation, minRowSpacing, minColumnSpacing, maxItemsPerLine);
_cachedFirstElement = null;
}
else
{
if (_cachedFirstElement == null)
{
// we only cache if we aren't realizing it
_cachedFirstElement = context.GetOrCreateElementAt(
0,
ElementRealizationOptions.ForceCreate | ElementRealizationOptions.SuppressAutoRecycle); // expensive
}
_cachedFirstElement.Measure(availableSize);
SetSize(_cachedFirstElement, layoutItemWidth, layoutItemHeight, availableSize, stretch, orientation, minRowSpacing, minColumnSpacing, maxItemsPerLine);
// See if we can move ownership to the flow algorithm. If we can, we do not need a local cache.
bool added = FlowAlgorithm.TryAddElement0(_cachedFirstElement);
if (added)
{
_cachedFirstElement = null;
}
}
}
}
internal void EnsureElementSize(
Size availableSize,
VirtualizingLayoutContext context,
double layoutItemWidth,
double LayoutItemHeight,
UniformGridLayoutItemsStretch stretch,
Orientation orientation,
double minRowSpacing,
double minColumnSpacing)
{
if (context.ItemCount > 0)
{
// If the first element is realized we don't need to cache it or to get it from the context
var realizedElement = FlowAlgorithm.GetElementIfRealized(0);
if (realizedElement != null)
{
realizedElement.Measure(availableSize);
SetSize(realizedElement, layoutItemWidth, LayoutItemHeight, availableSize, stretch, orientation, minRowSpacing, minColumnSpacing);
_cachedFirstElement = null;
}
else
{
if (_cachedFirstElement == null)
{
// we only cache if we aren't realizing it
_cachedFirstElement = context.GetOrCreateElementAt(
0,
ElementRealizationOptions.ForceCreate | ElementRealizationOptions.SuppressAutoRecycle); // expensive
}
_cachedFirstElement.Measure(availableSize);
// This doesn't need to be done in the UWP version and I'm not sure why. If we
// don't do this here, and we receive a recycled element then it will be shown
// at its previous arrange point, but we don't want it shown at all until its
// arranged.
_cachedFirstElement.Arrange(new Rect(-10000.0, -10000.0, 0, 0));
SetSize(_cachedFirstElement, layoutItemWidth, LayoutItemHeight, availableSize, stretch, orientation, minRowSpacing, minColumnSpacing);
// See if we can move ownership to the flow algorithm. If we can, we do not need a local cache.
bool added = FlowAlgorithm.TryAddElement0(_cachedFirstElement);
if (added)
{
_cachedFirstElement = null;
}
}
}
}
internal void EnsureElementSize(
Size availableSize,
VirtualizingLayoutContext context,
double layoutItemWidth,
double LayoutItemHeight,
UniformGridLayoutItemsStretch stretch,
Orientation orientation,
double minRowSpacing,
double minColumnSpacing,
uint maxItemsPerLine)
{
if (maxItemsPerLine == 0)
{
maxItemsPerLine = 1;
}
if (context.ItemCount > 0)
{
// If the first element is realized we don't need to get it from the context
var realizedElement = m_flowAlgorithm.GetElementIfRealized(0);
if (realizedElement is { })
internal void EnsureElementSize(
Size availableSize,
VirtualizingLayoutContext context,
double layoutItemWidth,
double LayoutItemHeight,
UniformGridLayoutItemsStretch stretch,
Orientation orientation,
double minRowSpacing,
double minColumnSpacing,
uint maxItemsPerLine)
{
if (maxItemsPerLine == 0)
{
maxItemsPerLine = 1;
}
if (context.ItemCount > 0)
{
// If the first element is realized we don't need to get it from the context
var realizedElement = FlowAlgorithm.GetElementIfRealized(0);
if (realizedElement != null)
{
realizedElement.Measure(availableSize);
SetSize(realizedElement.DesiredSize, layoutItemWidth, LayoutItemHeight, availableSize, stretch, orientation, minRowSpacing, minColumnSpacing, maxItemsPerLine);
}
else
{
// Not realized by flowlayout, so do this now!
if (context.GetOrCreateElementAt(0, ElementRealizationOptions.ForceCreate) is { } firstElement)
{
firstElement.Measure(availableSize);
SetSize(firstElement.DesiredSize, layoutItemWidth, LayoutItemHeight, availableSize, stretch, orientation, minRowSpacing, minColumnSpacing, maxItemsPerLine);
context.RecycleElement(firstElement);
}
}
}
}
private void SetSize(UIElement UIElement,
double layoutItemWidth,
double LayoutItemHeight,
Size availableSize,
UniformGridLayoutItemsStretch stretch,
Orientation orientation,
double minRowSpacing,
double minColumnSpacing,
uint maxItemsPerLine)
{
if (maxItemsPerLine == 0)
{
maxItemsPerLine = 1;
}
EffectiveItemWidth = double.IsNaN(layoutItemWidth) ? UIElement.DesiredSize.Width : layoutItemWidth;
EffectiveItemHeight = double.IsNaN(LayoutItemHeight) ? UIElement.DesiredSize.Height : LayoutItemHeight;
var availableSizeMinor = orientation == Orientation.Horizontal ? availableSize.Width : availableSize.Height;
var minorItemSpacing = orientation == Orientation.Vertical ? minRowSpacing : minColumnSpacing;
var itemSizeMinor = orientation == Orientation.Horizontal ? EffectiveItemWidth : EffectiveItemHeight;
double extraMinorPixelsForEachItem = 0.0;
if (!double.IsInfinity(availableSizeMinor))
{
var numItemsPerColumn = Math.Min(
maxItemsPerLine,
(uint)Math.Max(1.0, availableSizeMinor / (itemSizeMinor + minorItemSpacing)));
var usedSpace = (numItemsPerColumn * (itemSizeMinor + minorItemSpacing)) - minorItemSpacing;
var remainingSpace = ((int)(availableSizeMinor - usedSpace));
extraMinorPixelsForEachItem = remainingSpace / ((int)numItemsPerColumn);
}
if (stretch == UniformGridLayoutItemsStretch.Fill)
{
if (orientation == Orientation.Horizontal)
{
EffectiveItemWidth += extraMinorPixelsForEachItem;
}
else
{
EffectiveItemHeight += extraMinorPixelsForEachItem;
}
}
else if (stretch == UniformGridLayoutItemsStretch.Uniform)
{
var itemSizeMajor = orientation == Orientation.Horizontal ? EffectiveItemHeight : EffectiveItemWidth;
var extraMajorPixelsForEachItem = itemSizeMajor * (extraMinorPixelsForEachItem / itemSizeMinor);
if (orientation == Orientation.Horizontal)
{
EffectiveItemWidth += extraMinorPixelsForEachItem;
EffectiveItemHeight += extraMajorPixelsForEachItem;
}
else
{
EffectiveItemHeight += extraMinorPixelsForEachItem;
EffectiveItemWidth += extraMajorPixelsForEachItem;
}
}
}
