/// <summary>
/// Override for <seealso cref="UIElement.MeasureCore" />.
/// </summary>
protected sealed override Size MeasureCore(Size availableSize)
{
Debug.Assert(MeasureData == null || availableSize == MeasureData.AvailableSize, "MeasureData needs to be passed down in [....] with size");
// If using layout rounding, check whether rounding needs to compensate for high DPI
bool useLayoutRounding = this.UseLayoutRounding;
if (useLayoutRounding)
{
if (!CheckFlagsAnd(VisualFlags.UseLayoutRounding))
{
this.SetFlags(true, VisualFlags.UseLayoutRounding);
}
}
//build the visual tree from styles first
ApplyTemplate();
if (BypassLayoutPolicies)
{
return MeasureOverride(availableSize);
}
else
{
Thickness margin = Margin;
double marginWidth = margin.Left + margin.Right;
double marginHeight = margin.Top + margin.Bottom;
MeasureData measureData = MeasureData;
// parent size is what parent want us to be
Size frameworkAvailableSize = new Size(
Math.Max(availableSize.Width - marginWidth, 0),
Math.Max(availableSize.Height - marginHeight, 0));
MinMax mm = new MinMax(this);
LayoutTransformData ltd = LayoutTransformDataField.GetValue(this);
{
Transform layoutTransform = this.LayoutTransform;
// check that LayoutTransform is non-trivial
if (layoutTransform != null && !layoutTransform.IsIdentity)
{
if (ltd == null)
{
// allocate and store ltd if needed
ltd = new LayoutTransformData();
LayoutTransformDataField.SetValue(this, ltd);
}
ltd.CreateTransformSnapshot(layoutTransform);
ltd.UntransformedDS = new Size();
if (useLayoutRounding)
{
ltd.TransformedUnroundedDS = new Size();
}
}
else if (ltd != null)
{
// clear ltd storage
ltd = null;
LayoutTransformDataField.ClearValue(this);
}
}
if (ltd != null)
{
// Find the maximal area rectangle in local (child) space that we can fit, post-transform
// in the decorator's measure constraint.
frameworkAvailableSize = FindMaximalAreaLocalSpaceRect(ltd.Transform, frameworkAvailableSize);
}
frameworkAvailableSize.Width = Math.Max(mm.minWidth, Math.Min(frameworkAvailableSize.Width, mm.maxWidth));
frameworkAvailableSize.Height = Math.Max(mm.minHeight, Math.Min(frameworkAvailableSize.Height, mm.maxHeight));
// If layout rounding is enabled, round available size passed to MeasureOverride.
if (useLayoutRounding)
{
frameworkAvailableSize = UIElement.RoundLayoutSize(frameworkAvailableSize, FrameworkElement.DpiScaleX, FrameworkElement.DpiScaleY);
}
// call to specific layout to measure
if (measureData != null)
{
measureData.AvailableSize = frameworkAvailableSize;
}
Size desiredSize = MeasureOverride(frameworkAvailableSize);
if (measureData != null)
{
// MeasureData should be treated like a parameter to Measure and thus not modified when returning from this call.
measureData.AvailableSize = availableSize;
}
// maximize desiredSize with user provided min size
desiredSize = new Size(
Math.Max(desiredSize.Width, mm.minWidth),
Math.Max(desiredSize.Height, mm.minHeight));
//here is the "true minimum" desired size - the one that is
//for sure enough for the control to render its content.
Size unclippedDesiredSize = desiredSize;
if (ltd != null)
{
//need to store unclipped, untransformed desired size to be able to arrange later
ltd.UntransformedDS = unclippedDesiredSize;
//transform unclipped desired size
Rect unclippedBoundsTransformed = Rect.Transform(new Rect(0, 0, unclippedDesiredSize.Width, unclippedDesiredSize.Height), ltd.Transform.Value);
unclippedDesiredSize.Width = unclippedBoundsTransformed.Width;
unclippedDesiredSize.Height = unclippedBoundsTransformed.Height;
}
bool clipped = false;
// User-specified max size starts to "clip" the control here.
//Starting from this point desiredSize could be smaller then actually
//needed to render the whole control
if (desiredSize.Width > mm.maxWidth)
{
desiredSize.Width = mm.maxWidth;
clipped = true;
}
if (desiredSize.Height > mm.maxHeight)
{
desiredSize.Height = mm.maxHeight;
clipped = true;
}
//transform desired size to layout slot space
if (ltd != null)
{
Rect childBoundsTransformed = Rect.Transform(new Rect(0, 0, desiredSize.Width, desiredSize.Height), ltd.Transform.Value);
desiredSize.Width = childBoundsTransformed.Width;
desiredSize.Height = childBoundsTransformed.Height;
}
// because of negative margins, clipped desired size may be negative.
// need to keep it as doubles for that reason and maximize with 0 at the
// very last point - before returning desired size to the parent.
double clippedDesiredWidth = desiredSize.Width + marginWidth;
double clippedDesiredHeight = desiredSize.Height + marginHeight;
// In overconstrained scenario, parent wins and measured size of the child,
// including any sizes set or computed, can not be larger then
// available size. We will clip the guy later.
if (clippedDesiredWidth > availableSize.Width)
{
clippedDesiredWidth = availableSize.Width;
clipped = true;
}
if (clippedDesiredHeight > availableSize.Height)
{
clippedDesiredHeight = availableSize.Height;
clipped = true;
}
// Set transformed, unrounded size on layout transform, if any.
if (ltd != null)
{
ltd.TransformedUnroundedDS = new Size(Math.Max(0, clippedDesiredWidth), Math.Max(0, clippedDesiredHeight));
}
// If using layout rounding, round desired size.
if (useLayoutRounding)
{
clippedDesiredWidth = UIElement.RoundLayoutValue(clippedDesiredWidth, DpiScaleX);
clippedDesiredHeight = UIElement.RoundLayoutValue(clippedDesiredHeight, DpiScaleY);
}
// Note: unclippedDesiredSize is needed in ArrangeCore,
// because due to the layout protocol, arrange should be called
// with constraints greater or equal to child's desired size
// returned from MeasureOverride. But in most circumstances
// it is possible to reconstruct original unclipped desired size.
// In such cases we want to optimize space and save 16 bytes by
// not storing it on each FrameworkElement.
//
// The if statement conditions below lists the cases when
// it is NOT possible to recalculate unclipped desired size later
// in ArrangeCore, thus we save it into Uncommon Fields...
//
// Note 2: use SizeBox to avoid CLR boxing of Size.
// measurements show it is better to allocate an object once than
// have spurious boxing allocations on every resize
SizeBox sb = UnclippedDesiredSizeField.GetValue(this);
if (clipped
|| clippedDesiredWidth < 0
|| clippedDesiredHeight < 0)
{
if (sb == null) //not yet allocated, allocate the box
{
sb = new SizeBox(unclippedDesiredSize);
UnclippedDesiredSizeField.SetValue(this, sb);
}
else //we already have allocated size box, simply change it
{
sb.Width = unclippedDesiredSize.Width;
sb.Height = unclippedDesiredSize.Height;
}
}
else
{
if (sb != null)
UnclippedDesiredSizeField.ClearValue(this);
}
return new Size(Math.Max(0, clippedDesiredWidth), Math.Max(0, clippedDesiredHeight));
}
}
protected override sealed Size MeasureCore(Size availableSize)
{
bool useLayoutRounding = this.UseLayoutRounding;
if (useLayoutRounding && !this.CheckFlagsAnd(VisualFlags.UseLayoutRounding))
this.SetFlags(true, VisualFlags.UseLayoutRounding);
this.ApplyTemplate();
if (this.BypassLayoutPolicies)
return this.MeasureOverride(availableSize);
Thickness margin = this.Margin;
double num1 = margin.Left + margin.Right;
double num2 = margin.Top + margin.Bottom;
if (useLayoutRounding && this is ScrollContentPresenter)
{
num1 = UIElement.RoundLayoutValue(num1, FrameworkElement.DpiScaleX);
num2 = UIElement.RoundLayoutValue(num2, FrameworkElement.DpiScaleY);
}
Size size1 = new Size(Math.Max(availableSize.Width - num1, 0.0), Math.Max(availableSize.Height - num2, 0.0));
FrameworkElement.MinMax minMax = new FrameworkElement.MinMax(this);
FrameworkElement.LayoutTransformData layoutTransformData = FrameworkElement.LayoutTransformDataField.GetValue((DependencyObject) this);
Transform layoutTransform = this.LayoutTransform;
if (layoutTransform != null && !layoutTransform.IsIdentity)
{
if (layoutTransformData == null)
{
layoutTransformData = new FrameworkElement.LayoutTransformData();
FrameworkElement.LayoutTransformDataField.SetValue((DependencyObject) this, layoutTransformData);
}
layoutTransformData.CreateTransformSnapshot(layoutTransform);
layoutTransformData.UntransformedDS = new Size();
if (useLayoutRounding)
layoutTransformData.TransformedUnroundedDS = new Size();
}
else if (layoutTransformData != null)
{
layoutTransformData = (FrameworkElement.LayoutTransformData) null;
FrameworkElement.LayoutTransformDataField.ClearValue((DependencyObject) this);
}
if (layoutTransformData != null)
size1 = this.FindMaximalAreaLocalSpaceRect(layoutTransformData.Transform, size1);
size1.Width = Math.Max(minMax.minWidth, Math.Min(size1.Width, minMax.maxWidth));
size1.Height = Math.Max(minMax.minHeight, Math.Min(size1.Height, minMax.maxHeight));
if (useLayoutRounding)
size1 = UIElement.RoundLayoutSize(size1, FrameworkElement.DpiScaleX, FrameworkElement.DpiScaleY);
Size size2 = this.MeasureOverride(size1);
size2 = new Size(Math.Max(size2.Width, minMax.minWidth), Math.Max(size2.Height, minMax.minHeight));
Size size3 = size2;
if (layoutTransformData != null)
{
layoutTransformData.UntransformedDS = size3;
Rect rect = Rect.Transform(new Rect(0.0, 0.0, size3.Width, size3.Height), layoutTransformData.Transform.Value);
size3.Width = rect.Width;
size3.Height = rect.Height;
}
bool flag = false;
if (size2.Width > minMax.maxWidth)
{
size2.Width = minMax.maxWidth;
flag = true;
}
if (size2.Height > minMax.maxHeight)
{
size2.Height = minMax.maxHeight;
flag = true;
}
if (layoutTransformData != null)
{
Rect rect = Rect.Transform(new Rect(0.0, 0.0, size2.Width, size2.Height), layoutTransformData.Transform.Value);
size2.Width = rect.Width;
size2.Height = rect.Height;
}
double val2_1 = size2.Width + num1;
double val2_2 = size2.Height + num2;
if (val2_1 > availableSize.Width)
{
val2_1 = availableSize.Width;
flag = true;
}
if (val2_2 > availableSize.Height)
{
val2_2 = availableSize.Height;
flag = true;
}
if (layoutTransformData != null)
layoutTransformData.TransformedUnroundedDS = new Size(Math.Max(0.0, val2_1), Math.Max(0.0, val2_2));
if (useLayoutRounding)
{
val2_1 = UIElement.RoundLayoutValue(val2_1, FrameworkElement.DpiScaleX);
val2_2 = UIElement.RoundLayoutValue(val2_2, FrameworkElement.DpiScaleY);
}
SizeBox sizeBox1 = FrameworkElement.UnclippedDesiredSizeField.GetValue((DependencyObject) this);
if (flag || val2_1 < 0.0 || val2_2 < 0.0)
{
if (sizeBox1 == null)
{
SizeBox sizeBox2 = new SizeBox(size3);
FrameworkElement.UnclippedDesiredSizeField.SetValue((DependencyObject) this, sizeBox2);
}
else
{
sizeBox1.Width = size3.Width;
sizeBox1.Height = size3.Height;
}
}
else if (sizeBox1 != null)
FrameworkElement.UnclippedDesiredSizeField.ClearValue((DependencyObject) this);
return new Size(Math.Max(0.0, val2_1), Math.Max(0.0, val2_2));
}