public override Size MeasureDesiredSize(Size availableSize)
{
// Cleanse our child information first
ConsolidateChildInformation();
// First step let's sum up all of our row/column constant and star height/widths. Whilst we're
// doing this we we can set the actual widths/heights of constantly defined height columns and rows.
double heightConstants = 0;
double heightStars = 0;
double widthConstants = 0;
double widthStars = 0;
for (int i = 0; i < (RowDefinitions.Count < 1 ? 1 : RowDefinitions.Count); i++)
{
RowDefinition rd = GetRow(i);
if (rd.Height.Type == GridLengthType.Pixel)
{
double originalHeightConstants = heightConstants;
heightConstants += rd.Height.Length;
if (heightConstants <= availableSize.Height)
{
rd.ActualHeight = rd.Height.Length;
}
else if (originalHeightConstants <= availableSize.Height)
{
rd.ActualHeight = heightConstants - originalHeightConstants;
}
else
{
rd.ActualHeight = 0;
}
}
else
{
rd.ActualHeight = double.NaN;
if (rd.Height.Type == GridLengthType.Star)
{
heightStars += rd.Height.Length;
}
}
}
for (int i = 0; i < (ColumnDefinitions.Count < 1 ? 1 : ColumnDefinitions.Count); i++)
{
ColumnDefinition cd = GetColumn(i);
if (cd.Width.Type == GridLengthType.Pixel)
{
double originalWidthConstants = widthConstants;
widthConstants += cd.Width.Length;
if (widthConstants <= availableSize.Width)
{
cd.ActualWidth = cd.Width.Length;
}
else if (originalWidthConstants <= availableSize.Width)
{
cd.ActualWidth = widthConstants - originalWidthConstants;
}
else
{
cd.ActualWidth = 0;
}
}
else
{
cd.ActualWidth = double.NaN;
if (cd.Width.Type == GridLengthType.Star)
{
widthStars += cd.Width.Length;
}
}
}
// Work out height/widths for autos and treat stars the same for measure except we don't actually set an actual width/height (or deduct from available) for autos for now
double remainingHeight = availableSize.Height - heightConstants;
double remainingWidth = availableSize.Width - widthConstants;
for (int rowNumber = 0; rowNumber < (RowDefinitions.Count < 1 ? 1 : RowDefinitions.Count); rowNumber++)
{
RowDefinition rd = GetRow(rowNumber);
for (int columnNumber = 0; columnNumber < (ColumnDefinitions.Count < 1 ? 1 : ColumnDefinitions.Count); columnNumber++)
{
ColumnDefinition cd = GetColumn(columnNumber);
// Skip this cell if both RD/CD are constant
if (rd.Height.Type == GridLengthType.Pixel && cd.Width.Type == GridLengthType.Pixel)
{
continue;
}
// Skip this cell if no children
Control[] cellChildren = _childInformation.Where(ci => (ci.Row == rowNumber || (ci.Row >= RowDefinitions.Count && rowNumber == RowDefinitions.Count - 1)) && (ci.Column == columnNumber || (ci.Column >= ColumnDefinitions.Count && columnNumber == ColumnDefinitions.Count - 1))).Select(ci => ci.Child).ToArray();
if (cellChildren.Length < 1)
{
continue;
}
// Determine available size for this cell (factoring in any pre-calculated dimensions)
Size cellAvailableSize = new Size(remainingWidth, remainingHeight);
if (cd.Width.Type == GridLengthType.Pixel)
{
cellAvailableSize.Width = cd.ActualWidth;
}
else if (!double.IsNaN(cd.ActualWidth))
{
cellAvailableSize.Width += cd.ActualWidth;
}
if (rd.Height.Type == GridLengthType.Pixel)
{
cellAvailableSize.Height = rd.ActualHeight;
}
else if (!double.IsNaN(rd.ActualHeight))
{
cellAvailableSize.Height += rd.ActualHeight;
}
// Now for this particular cell ask each child to measure and find biggest dimensions
Size biggestCellChildSize = new Size(0, 0);
foreach (Control cellChild in cellChildren)
{
// For this measure we first swap-out any stretch alignments
bool wasStretchHorizontal = cellChild.HorizontalAlignment == HorizontalAlignment.Stretch;
bool wasStretchVertical = cellChild.VerticalAlignment == VerticalAlignment.Stretch;
if (wasStretchHorizontal)
{
cellChild.HorizontalAlignment = HorizontalAlignment.Left;
}
if (wasStretchVertical)
{
cellChild.VerticalAlignment = VerticalAlignment.Top;
}
// Now perform the measure
Size cellChildSize = cellChild.MeasureDesiredSize(cellAvailableSize);
cellChildSize.Width += cellChild.Margin.Left + cellChild.Margin.Right;
cellChildSize.Height += cellChild.Margin.Top + cellChild.Margin.Bottom;
if (cellChildSize.Width > biggestCellChildSize.Width)
{
biggestCellChildSize.Width = cellChildSize.Width;
}
if (cellChildSize.Height > biggestCellChildSize.Height)
{
biggestCellChildSize.Height = cellChildSize.Height;
}
// Reset stretch if required
if (wasStretchHorizontal)
{
cellChild.HorizontalAlignment = HorizontalAlignment.Stretch;
}
if (wasStretchVertical)
{
cellChild.VerticalAlignment = VerticalAlignment.Stretch;
}
}
// Update the row/column definitions to have actual height/width if currently and determine offset here from already calculated and
// update the remaining width/height accordingly
if (cd.Width.Type == GridLengthType.Auto && (double.IsNaN(cd.ActualWidth) || biggestCellChildSize.Width > cd.ActualWidth))
{
double originalWidth = double.IsNaN(cd.ActualWidth) ? 0 : cd.ActualWidth;
cd.ActualWidth = biggestCellChildSize.Width;
double widthDifference = cd.ActualWidth - originalWidth;
remainingWidth -= widthDifference;
}
if (rd.Height.Type == GridLengthType.Auto && (double.IsNaN(rd.ActualHeight) || biggestCellChildSize.Height > rd.ActualHeight))
{
double originalHeight = double.IsNaN(rd.ActualHeight) ? 0 : rd.ActualHeight;
rd.ActualHeight = biggestCellChildSize.Height;
double HeightDifference = rd.ActualHeight - originalHeight;
remainingHeight -= HeightDifference;
}
}
}
// Now distribute stars accordingly - currently these cells will have been fit by auto. We should now look at all remaining space and divvy it up
// accordingly for star cells
if (widthStars > 0)
{
double widthPerStar = remainingWidth / widthStars;
for (int columnNumber = 0; columnNumber < (ColumnDefinitions.Count < 1 ? 1 : ColumnDefinitions.Count); columnNumber++)
{
ColumnDefinition cd = GetColumn(columnNumber);
if (cd.Width.Type != GridLengthType.Star)
{
continue;
}
double starSize = widthPerStar * cd.Width.Length;
if (double.IsNaN(cd.ActualWidth) || starSize > cd.ActualWidth)
{
cd.ActualWidth = starSize;
}
}
remainingWidth = 0;
}
if (heightStars > 0)
{
double heightPerStar = remainingHeight / heightStars;
for (int rowNumber = 0; rowNumber < (RowDefinitions.Count < 1 ? 1 : RowDefinitions.Count); rowNumber++)
{
RowDefinition rd = GetRow(rowNumber);
if (rd.Height.Type != GridLengthType.Star)
{
continue;
}
double starSize = heightPerStar * rd.Height.Length;
if (double.IsNaN(rd.ActualHeight) || starSize > rd.ActualHeight)
{
rd.ActualHeight = starSize;
}
}
remainingHeight = 0;
}
// All actual height/widths for columsn and rows are calculated so lets store our summary of these to use in render
double offsetRow = 0;
double offsetColumn = 0;
for (int rowNumber = 0; rowNumber < (RowDefinitions.Count < 1 ? 1 : RowDefinitions.Count); rowNumber++)
{
RowDefinition rd = GetRow(rowNumber);
rd.ActualOffset = offsetRow;
offsetRow += rd.ActualHeight;
}
for (int columnNumber = 0; columnNumber < (ColumnDefinitions.Count < 1 ? 1 : ColumnDefinitions.Count); columnNumber++)
{
ColumnDefinition cd = GetColumn(columnNumber);
cd.ActualOffset = offsetColumn;
offsetColumn += cd.ActualWidth;
}
// For each child we can now put in widths/heights as required - do this in to their Measure() and set actual size
int zIndex = 0;
for (int rowNumber = 0; rowNumber < (RowDefinitions.Count < 1 ? 1 : RowDefinitions.Count); rowNumber++)
{
RowDefinition rd = GetRow(rowNumber);
for (int columnNumber = 0; columnNumber < (ColumnDefinitions.Count < 1 ? 1 : ColumnDefinitions.Count); columnNumber++)
{
ColumnDefinition cd = GetColumn(columnNumber);
// Tell the child its actual size that we'll be using
Control[] cellChildren = _childInformation.Where(ci => (ci.Row == rowNumber || (ci.Row >= RowDefinitions.Count && rowNumber == RowDefinitions.Count - 1)) && (ci.Column == columnNumber || (ci.Column >= ColumnDefinitions.Count && columnNumber == ColumnDefinitions.Count - 1))).Select(ci => ci.Child).ToArray();
foreach (Control child in cellChildren)
{
// Determine available size for child minus its margins
Size measureSize = new Size(cd.ActualWidth, rd.ActualHeight);
measureSize.Width -= child.Margin.Left;
measureSize.Width -= child.Margin.Right;
measureSize.Height -= child.Margin.Top;
measureSize.Height -= child.Margin.Bottom;
// Get the child to measure
Size childActualSize = child.MeasureDesiredSize(measureSize);
// Cap measurement at appropriate max bounds and allow for stretch
if (childActualSize.Width > measureSize.Width)
{
childActualSize.Width = measureSize.Width;
}
if (childActualSize.Height > measureSize.Height)
{
childActualSize.Height = measureSize.Height;
}
if (child.HorizontalAlignment == HorizontalAlignment.Stretch)
{
childActualSize.Width = measureSize.Width;
}
if (child.VerticalAlignment == VerticalAlignment.Stretch)
{
childActualSize.Height = measureSize.Height;
}
// Give the child the space required
child.SetActualSize(childActualSize);
// Setup layout information
double x = cd.ActualOffset;
double y = rd.ActualOffset;
switch (child.HorizontalAlignment)
{
case HorizontalAlignment.Stretch:
case HorizontalAlignment.Left:
x += child.Margin.Left;
break;
case HorizontalAlignment.Right:
x += cd.ActualWidth - child.Margin.Right - childActualSize.Width;
break;
case HorizontalAlignment.Middle:
x += (cd.ActualWidth / 2) - ((child.Margin.Left + child.Margin.Right + childActualSize.Width) / 2);
break;
default:
throw new Exception("Unsupported horizontal alignment");
}
switch (child.VerticalAlignment)
{
case VerticalAlignment.Stretch:
case VerticalAlignment.Top:
y += child.Margin.Top;
break;
case VerticalAlignment.Bottom:
y += rd.ActualHeight - child.Margin.Bottom - childActualSize.Height;
break;
case VerticalAlignment.Middle:
y += (rd.ActualHeight / 2) - ((child.Margin.Top + child.Margin.Bottom + childActualSize.Height) / 2);
break;
default:
throw new Exception("Unsupported vertical alignment");
}
LayoutInformation layoutInformation = GetLayoutInformationForChild(child);
layoutInformation.Rectangle = new Rectangle(x, y, child.ActualWidth, child.ActualHeight);
layoutInformation.ZIndex = zIndex++;
}
}
}
// Finally we return the size we will be using
return(new Size(availableSize.Width - remainingWidth, availableSize.Height - remainingHeight));
}
public override Size MeasureDesiredSize(Size availableSize)
{
// If we have no children this one is easy
if (Child == null)
{
return(HorizontalAlignment == HorizontalAlignment.Stretch && VerticalAlignment == VerticalAlignment.Stretch ? availableSize : new Size(0, 0));
}
// Determine actual available size for child by taking off our own internal spacings (i.e. borders etc)
double availableWidth = availableSize.Width - Child.Margin.Left - Child.Margin.Right - InternalSpacing.Left - InternalSpacing.Right;
double availableHeight = availableSize.Height - Child.Margin.Top - Child.Margin.Bottom - InternalSpacing.Top - InternalSpacing.Bottom;
// Perform a measure pass on this child and set its size
Size childSize = Child.MeasureDesiredSize(new Size(availableWidth, availableHeight));
Child.SetActualSize(childSize);
// Decide the width we will use
Size finalSizeToUse = new Size(childSize.Width + InternalSpacing.Left + InternalSpacing.Right + Child.Margin.Left + Child.Margin.Right, childSize.Height + InternalSpacing.Top + InternalSpacing.Bottom + Child.Margin.Top + Child.Margin.Bottom);
if (HorizontalAlignment == HorizontalAlignment.Stretch)
{
finalSizeToUse.Width = availableSize.Width;
}
if (VerticalAlignment == VerticalAlignment.Stretch)
{
finalSizeToUse.Height = availableSize.Height;
}
// Now we have the desired sizing information we can setup its layout information for painting later on
double x;
switch (Child.HorizontalAlignment)
{
case HorizontalAlignment.Stretch:
case HorizontalAlignment.Left:
x = Child.Margin.Left + InternalSpacing.Left;
break;
case HorizontalAlignment.Right:
x = finalSizeToUse.Width - Child.Margin.Right - childSize.Width - InternalSpacing.Right;
break;
case HorizontalAlignment.Middle:
x = (finalSizeToUse.Width / 2) - ((Child.Margin.Left + Child.Margin.Right + childSize.Width + InternalSpacing.Left + InternalSpacing.Right) / 2);
break;
default:
throw new Exception("Unsupported horizontal alignment");
}
if (x < 0)
{
x = 0;
}
if (x > finalSizeToUse.Width)
{
x = finalSizeToUse.Width;
}
double y;
switch (Child.VerticalAlignment)
{
case VerticalAlignment.Stretch:
case VerticalAlignment.Top:
y = Child.Margin.Top + InternalSpacing.Top;
break;
case VerticalAlignment.Bottom:
y = finalSizeToUse.Height - Child.Margin.Bottom - childSize.Height - InternalSpacing.Bottom;
break;
case VerticalAlignment.Middle:
y = (finalSizeToUse.Height / 2) - ((Child.Margin.Top + Child.Margin.Bottom + childSize.Height + InternalSpacing.Top + InternalSpacing.Bottom) / 2);
break;
default:
throw new Exception("Unsupported vertical alignment");
}
if (y < 0)
{
y = 0;
}
if (y > finalSizeToUse.Height)
{
y = finalSizeToUse.Height;
}
LayoutInformation layoutInformation = GetLayoutInformationForChild(Child);
layoutInformation.Rectangle = new Rectangle(x, y, childSize.Width, childSize.Height);
layoutInformation.ZIndex = 0;
// Return size including our borders and child margins factoring in any stretch
return(finalSizeToUse);
}
