private MeasuredSize measureChild(global::System.IntPtr childPtr, float width, int measureModeWidth, float height, int measureModeHeight)
{
// We need to measure child layout
View child = Registry.GetManagedBaseHandleFromNativePtr(childPtr) as View;
LayoutItem childLayout = child.Layout;
MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(
new LayoutLength(parentMeasureSpecificationWidth.Size - (child.Margin.Start + child.Margin.End)),
parentMeasureSpecificationWidth.Mode),
new LayoutLength(Padding.Start + Padding.End),
new LayoutLength(child.WidthSpecification));
MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(
new LayoutLength(parentMeasureSpecificationHeight.Size - (child.Margin.Top + child.Margin.Bottom)),
parentMeasureSpecificationHeight.Mode),
new LayoutLength(Padding.Top + Padding.Bottom),
new LayoutLength(child.HeightSpecification));
childLayout.Measure( childWidthMeasureSpec, childHeightMeasureSpec);
return new MeasuredSize(childLayout.MeasuredWidth.Size.AsRoundedValue(),childLayout.MeasuredHeight.Size.AsRoundedValue());
}
/// <summary>
/// Ask one of the children of this view to measure itself, taking into
/// account both the MeasureSpec requirements for this view and its padding.<br />
/// and margins. The heavy lifting is done in GetChildMeasureSpecification.<br />
/// </summary>
/// <param name="child">The child to measure.</param>
/// <param name="parentWidthMeasureSpec">The width requirements for this view.</param>
/// <param name="widthUsed">Extra space that has been used up by the parent horizontally (possibly by other children of the parent).</param>
/// <param name="parentHeightMeasureSpec">The height requirements for this view.</param>
/// <param name="heightUsed">Extra space that has been used up by the parent vertically (possibly by other children of the parent).</param>
/// <exception cref="ArgumentNullException"> Thrown when child is null. </exception>
/// <since_tizen> 6 </since_tizen>
protected virtual void MeasureChildWithMargins(LayoutItem child, MeasureSpecification parentWidthMeasureSpec, LayoutLength widthUsed, MeasureSpecification parentHeightMeasureSpec, LayoutLength heightUsed)
{
if (null == child)
{
throw new ArgumentNullException(nameof(child));
}
View childOwner = child.Owner;
Extents margin = childOwner.Margin;
MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(
new LayoutLength(parentWidthMeasureSpec.Size + widthUsed - (margin.Start + margin.End)),
parentWidthMeasureSpec.Mode),
new LayoutLength(Padding.Start + Padding.End),
new LayoutLength(childOwner.WidthSpecification));
MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(
new LayoutLength(parentHeightMeasureSpec.Size + heightUsed - (margin.Top + margin.Bottom)),
parentHeightMeasureSpec.Mode),
new LayoutLength(Padding.Top + Padding.Bottom),
new LayoutLength(childOwner.HeightSpecification));
child.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
private void MeasureWeightedChild(LayoutItem childLayout, float totalWeightLength, float totalWeight, float childWeight,
MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec,
HeightAndWidthState childState, Orientation orientation)
{
bool horizontal = false;
if (orientation == Orientation.Horizontal)
{
horizontal = true;
}
float childsShare = totalWeightLength * (childWeight / totalWeight);
float desiredWidth = childLayout.Owner.WidthSpecification;
float desiredHeight = childLayout.Owner.HeightSpecification;
MeasureSpecification childWidthMeasureSpec;
MeasureSpecification childHeightMeasureSpec;
if (horizontal)
{
childWidthMeasureSpec = new MeasureSpecification(new LayoutLength(childsShare - (childLayout.Margin.Start + childLayout.Margin.End)), MeasureSpecification.ModeType.Exactly);
childHeightMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(
new LayoutLength(heightMeasureSpec.Size - (childLayout.Margin.Top + childLayout.Margin.Bottom)),
heightMeasureSpec.Mode),
new LayoutLength(Padding.Top + Padding.Bottom),
new LayoutLength(desiredHeight));
}
else // vertical
{
childWidthMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(
new LayoutLength(widthMeasureSpec.Size - (childLayout.Margin.Start + childLayout.Margin.End)),
widthMeasureSpec.Mode),
new LayoutLength(Padding.Start + Padding.End),
new LayoutLength(desiredWidth));
childHeightMeasureSpec = new MeasureSpecification(new LayoutLength(childsShare - (childLayout.Margin.Top + childLayout.Margin.Bottom)), MeasureSpecification.ModeType.Exactly);
}
childLayout.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
// Child may now not fit in horizontal dimension.
if (childLayout.MeasuredWidth.State == MeasuredSize.StateType.MeasuredSizeTooSmall)
{
childState.widthState = MeasuredSize.StateType.MeasuredSizeTooSmall;
}
// Child may now not fit in vertical dimension.
if (childLayout.MeasuredHeight.State == MeasuredSize.StateType.MeasuredSizeTooSmall)
{
childState.heightState = MeasuredSize.StateType.MeasuredSizeTooSmall;
}
}
/// <summary>
/// Ask one of the children of this view to measure itself, taking into
/// account both the MeasureSpec requirements for this view and its padding.<br />
/// The heavy lifting is done in GetChildMeasureSpec.<br />
/// </summary>
/// <param name="child">The child to measure.</param>
/// <param name="parentWidthMeasureSpec">The width requirements for this view.</param>
/// <param name="parentHeightMeasureSpec">The height requirements for this view.</param>
protected virtual void MeasureChild(LayoutItem child, MeasureSpecification parentWidthMeasureSpec, MeasureSpecification parentHeightMeasureSpec)
{
View childOwner = child.Owner;
Extents padding = child.Padding; // Padding of this layout's owner, not of the child being measured.
MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(parentWidthMeasureSpec,
new LayoutLength(padding.Start + padding.End),
new LayoutLength(childOwner.WidthSpecification));
MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(parentHeightMeasureSpec,
new LayoutLength(padding.Top + padding.Bottom),
new LayoutLength(childOwner.HeightSpecification));
child.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
protected void MeasureChildWithoutPadding(LayoutItem child, MeasureSpecification parentWidthMeasureSpec, MeasureSpecification parentHeightMeasureSpec)
{
View childOwner = child.Owner;
MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(new LayoutLength(parentWidthMeasureSpec.Size), parentWidthMeasureSpec.Mode),
new LayoutLength(0),
new LayoutLength(childOwner.WidthSpecification));
MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(new LayoutLength(parentHeightMeasureSpec.Size), parentHeightMeasureSpec.Mode),
new LayoutLength(0),
new LayoutLength(childOwner.HeightSpecification));
child.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
/// <summary>
/// Ask one of the children of this view to measure itself, taking into
/// account both the MeasureSpec requirements for this view and its padding.<br />
/// The heavy lifting is done in GetChildMeasureSpecification.<br />
/// </summary>
/// <param name="child">The child to measure.</param>
/// <param name="parentWidthMeasureSpec">The width requirements for this view.</param>
/// <param name="parentHeightMeasureSpec">The height requirements for this view.</param>
/// <since_tizen> 6 </since_tizen>
protected virtual void MeasureChild(LayoutItem child, MeasureSpecification parentWidthMeasureSpec, MeasureSpecification parentHeightMeasureSpec)
{
View childOwner = child.Owner;
MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(new LayoutLength(parentWidthMeasureSpec.Size), parentWidthMeasureSpec.Mode),
new LayoutLength(Padding.Start + Padding.End),
new LayoutLength(childOwner.WidthSpecification));
MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(new LayoutLength(parentHeightMeasureSpec.Size), parentHeightMeasureSpec.Mode),
new LayoutLength(Padding.Top + Padding.Bottom),
new LayoutLength(childOwner.HeightSpecification));
child.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
/// <summary>
/// Ask one of the children of this view to measure itself, taking into
/// account both the MeasureSpec requirements for this view and its padding.<br />
/// and margins. The child must have MarginLayoutParams The heavy lifting is
/// done in GetChildMeasureSpecification.<br />
/// </summary>
/// <param name="child">The child to measure.</param>
/// <param name="parentWidthMeasureSpec">The width requirements for this view.</param>
/// <param name="widthUsed">Extra space that has been used up by the parent horizontally (possibly by other children of the parent).</param>
/// <param name="parentHeightMeasureSpec">The height requirements for this view.</param>
/// <param name="heightUsed">Extra space that has been used up by the parent vertically (possibly by other children of the parent).</param>
protected virtual void MeasureChildWithMargins(LayoutItem child, MeasureSpecification parentWidthMeasureSpec, LayoutLength widthUsed, MeasureSpecification parentHeightMeasureSpec, LayoutLength heightUsed)
{
View childOwner = child.Owner;
int desiredWidth = childOwner.WidthSpecification;
int desiredHeight = childOwner.HeightSpecification;
Extents padding = child.Padding; // Padding of this layout's owner, not of the child being measured.
MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(parentWidthMeasureSpec,
new LayoutLength(padding.Start + padding.End) +
widthUsed, new LayoutLength(desiredWidth));
MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(parentHeightMeasureSpec,
new LayoutLength(padding.Top + padding.Bottom) +
heightUsed, new LayoutLength(desiredHeight));
child.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
/// <summary>
/// Ask one of the children of this view to measure itself, taking into
/// account both the MeasureSpec requirements for this view and its padding.<br />
/// and margins. The child must have MarginLayoutParams The heavy lifting is
/// done in GetChildMeasureSpecification.<br />
/// </summary>
/// <param name="child">The child to measure.</param>
/// <param name="parentWidthMeasureSpec">The width requirements for this view.</param>
/// <param name="widthUsed">Extra space that has been used up by the parent horizontally (possibly by other children of the parent).</param>
/// <param name="parentHeightMeasureSpec">The height requirements for this view.</param>
/// <param name="heightUsed">Extra space that has been used up by the parent vertically (possibly by other children of the parent).</param>
/// <since_tizen> 6 </since_tizen>
protected virtual void MeasureChildWithMargins(LayoutItem child, MeasureSpecification parentWidthMeasureSpec, LayoutLength widthUsed, MeasureSpecification parentHeightMeasureSpec, LayoutLength heightUsed)
{
View childOwner = child.Owner;
MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(
new LayoutLength(parentWidthMeasureSpec.Size + widthUsed - (Padding.Start + Padding.End + childOwner.Margin.Start + childOwner.Margin.End)),
parentWidthMeasureSpec.Mode),
new LayoutLength(Padding.Start + Padding.End),
new LayoutLength(childOwner.WidthSpecification));
MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(
new LayoutLength(parentHeightMeasureSpec.Size + heightUsed - (Padding.Top + Padding.Bottom + childOwner.Margin.Top + childOwner.Margin.Bottom)),
parentHeightMeasureSpec.Mode),
new LayoutLength(Padding.Top + Padding.Bottom),
new LayoutLength(childOwner.HeightSpecification));
child.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
protected void MeasureChildWithoutPadding(LayoutItem child, MeasureSpecification parentWidthMeasureSpec, MeasureSpecification parentHeightMeasureSpec)
{
if (null == child)
{
throw new ArgumentNullException(nameof(child));
}
View childOwner = child.Owner;
MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(new LayoutLength(parentWidthMeasureSpec.Size), parentWidthMeasureSpec.Mode),
new LayoutLength(0),
new LayoutLength(childOwner.WidthSpecification));
MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(new LayoutLength(parentHeightMeasureSpec.Size), parentHeightMeasureSpec.Mode),
new LayoutLength(0),
new LayoutLength(childOwner.HeightSpecification));
child.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
private void MeasureWeightedChild(LayoutItem childLayout, float remainingExcess, float remainingWeight, float childWeight,
MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec,
HeightAndWidthState childState, Orientation orientation)
{
bool horizontal = false;
if (orientation == Orientation.Horizontal)
{
horizontal = true;
}
float childsShare = (childWeight * remainingExcess) / remainingWeight;
remainingExcess -= childsShare;
remainingWeight -= childWeight;
float desiredWidth = childLayout.Owner.WidthSpecification;
float desiredHeight = childLayout.Owner.HeightSpecification;
float childLength = 0;
// Always lay out weighted elements with intrinsic size regardless of the parent spec.
// for consistency between specs.
if ((horizontal && (desiredWidth == 0)) || (!horizontal && (desiredHeight == 0)))
{
// This child needs to be laid out from scratch using
// only its share of excess space.
childLength = childsShare;
}
else
{
// This child had some intrinsic width to which we
// need to add its share of excess space.
if (horizontal)
{
childLength = childLayout.MeasuredWidth.Size.AsDecimal() + childsShare;
}
else
{
childLength = childLayout.MeasuredHeight.Size.AsDecimal() + childsShare;
}
}
MeasureSpecification childWidthMeasureSpec;
MeasureSpecification childHeightMeasureSpec;
if (horizontal)
{
childWidthMeasureSpec = new MeasureSpecification(new LayoutLength(childLength), MeasureSpecification.ModeType.Exactly);
childHeightMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(
new LayoutLength(heightMeasureSpec.Size - (childLayout.Owner.Margin.Top + childLayout.Owner.Margin.Bottom)),
heightMeasureSpec.Mode),
new LayoutLength(Padding.Top + Padding.Bottom),
new LayoutLength(desiredHeight));
}
else // vertical
{
childWidthMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(
new LayoutLength(widthMeasureSpec.Size - (childLayout.Owner.Margin.Start + childLayout.Owner.Margin.End)),
widthMeasureSpec.Mode),
new LayoutLength(Padding.Start + Padding.End),
new LayoutLength(desiredWidth));
childHeightMeasureSpec = new MeasureSpecification(new LayoutLength(childLength), MeasureSpecification.ModeType.Exactly);
}
childLayout.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
// Child may now not fit in horizontal dimension.
if (childLayout.MeasuredWidth.State == MeasuredSize.StateType.MeasuredSizeTooSmall)
{
childState.widthState = MeasuredSize.StateType.MeasuredSizeTooSmall;
}
// Child may now not fit in vertical dimension.
if (childLayout.MeasuredHeight.State == MeasuredSize.StateType.MeasuredSizeTooSmall)
{
childState.heightState = MeasuredSize.StateType.MeasuredSizeTooSmall;
}
}
} // MeasureHorizontal
private void MeasureVertical(MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec)
{
var widthMode = widthMeasureSpec.Mode;
var heightMode = heightMeasureSpec.Mode;
bool isExactly = (heightMode == MeasureSpecification.ModeType.Exactly);
bool matchWidth = false;
bool allFillParent = true;
float maxWidth = 0.0f;
float alternativeMaxWidth = 0.0f;
float weightedMaxWidth = 0.0f;
float totalWeight = 0.0f;
// Reset total length
_totalLength = 0.0f;
float usedExcessSpace = 0.0f;
HeightAndWidthState childState = new HeightAndWidthState(MeasuredSize.StateType.MeasuredSizeOK,
MeasuredSize.StateType.MeasuredSizeOK);
// measure children, and determine if further resolution is required
// 1st phase:
// We cycle through all children and measure children with weight 0 (non weighted children) according to their specs
// to accumulate total used space in _totalLength.
// Weighted children are not measured in this phase.
// Available space for weighted children will be calculated in the phase 2 based on _totalLength value.
for (int i = 0; i < LayoutChildren.Count; i++)
{
LayoutItem childLayout = LayoutChildren[i];
int childDesiredWidth = childLayout.Owner.WidthSpecification;
float childWeight = childLayout.Owner.Weight;
Extents childMargin = childLayout.Margin;
totalWeight += childWeight;
bool useExcessSpace = (childLayout.Owner.HeightSpecification == 0) && (childWeight > 0);
if (isExactly && useExcessSpace)
{
_totalLength = Math.Max(_totalLength, (_totalLength + childMargin.Top + childMargin.Bottom));
}
else
{
if (useExcessSpace)
{
// The heightMode is either Unspecified or AtMost, and
// this child is only laid out using excess space. Measure
// using WrapContent so that we can find out the view's
// optimal height.
// We'll restore the original height of 0 after measurement.
MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(
new LayoutLength(widthMeasureSpec.Size - (childLayout.Margin.Start + childLayout.Margin.End)),
widthMeasureSpec.Mode),
new LayoutLength(Padding.Start + Padding.End),
new LayoutLength(childDesiredWidth));
MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(
new LayoutLength(heightMeasureSpec.Size - (childLayout.Margin.Top + childLayout.Margin.Bottom)),
heightMeasureSpec.Mode),
new LayoutLength(Padding.Top + Padding.Bottom),
new LayoutLength(LayoutParamPolicies.WrapContent));
childLayout.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
usedExcessSpace += childLayout.MeasuredHeight.Size.AsDecimal();
}
else
{
MeasureChildWithMargins(childLayout, widthMeasureSpec, new LayoutLength(0), heightMeasureSpec, new LayoutLength(0));
}
LayoutLength childHeight = childLayout.MeasuredHeight.Size;
LayoutLength length = childHeight + childMargin.Top + childMargin.Bottom;
if (isExactly)
{
_totalLength += length.AsDecimal();
}
else
{
_totalLength = Math.Max(_totalLength, _totalLength + length.AsDecimal() + (i < LayoutChildren.Count - 1 ? CellPadding.Height : 0));
}
}
bool matchWidthLocally = false;
if (widthMode != MeasureSpecification.ModeType.Exactly && childDesiredWidth == LayoutParamPolicies.MatchParent)
{
// Will have to re-measure at least this child when we know exact height.
matchWidth = true;
matchWidthLocally = true;
}
float marginWidth = childLayout.Margin.Start + childLayout.Margin.End;
float childWidth = childLayout.MeasuredWidth.Size.AsDecimal() + marginWidth;
if (childLayout.MeasuredWidth.State == MeasuredSize.StateType.MeasuredSizeTooSmall)
{
childState.widthState = MeasuredSize.StateType.MeasuredSizeTooSmall;
}
if (childLayout.MeasuredHeight.State == MeasuredSize.StateType.MeasuredSizeTooSmall)
{
childState.heightState = MeasuredSize.StateType.MeasuredSizeTooSmall;
}
maxWidth = Math.Max(maxWidth, childWidth);
allFillParent = (allFillParent && childDesiredWidth == LayoutParamPolicies.MatchParent);
if (childWeight > 0)
{
// Widths of weighted Views are bogus if we end up remeasuring, so keep them separate.
weightedMaxWidth = Math.Max(weightedMaxWidth, matchWidthLocally ? marginWidth : childWidth);
}
else
{
alternativeMaxWidth = Math.Max(alternativeMaxWidth, matchWidthLocally ? marginWidth : childWidth);
}
} // foreach
float heightSize = _totalLength;
heightSize = Math.Max(heightSize, SuggestedMinimumHeight.AsDecimal());
MeasuredSize heightSizeAndState = ResolveSizeAndState(new LayoutLength(heightSize + Padding.Top + Padding.Bottom), heightMeasureSpec, MeasuredSize.StateType.MeasuredSizeOK);
heightSize = heightSizeAndState.Size.AsDecimal();
// 2nd phase:
// We cycle through weighted children now (children with weight > 0).
// The children are measured with exact size equal to their share of the available space based on their weights.
// _totalLength is updated to include weighted children measured sizes.
float remainingExcess = heightSize - _totalLength + usedExcessSpace - (Padding.Top + Padding.Bottom);
if (remainingExcess != 0 && totalWeight > 0.0f)
{
float remainingWeight = totalWeight;
maxWidth = 0;
_totalLength = 0;
int numberOfChildren = LayoutChildren.Count;
for (int i = 0; i < numberOfChildren; ++i)
{
LayoutItem childLayout = LayoutChildren[i];
float desiredChildWidth = childLayout.Owner.WidthSpecification;
float childWeight = childLayout.Owner.Weight;
Extents childMargin = childLayout.Margin;
if (childWeight > 0)
{
MeasureWeightedChild(childLayout, remainingExcess, remainingWeight, childWeight,
widthMeasureSpec, heightMeasureSpec, childState,
Orientation.Vertical);
}
float length = childLayout.MeasuredHeight.Size.AsDecimal() + childMargin.Top + childMargin.Bottom;
float cellPadding = i < numberOfChildren - 1 ? CellPadding.Height : 0;
if (isExactly)
{
_totalLength += length;
}
else
{
float totalLength = _totalLength;
_totalLength = Math.Max(_totalLength, _totalLength + length + cellPadding);
}
bool matchWidthLocally = (widthMode != MeasureSpecification.ModeType.Exactly) && (desiredChildWidth == LayoutParamPolicies.MatchParent);
float marginWidth = childMargin.Start + childMargin.End;
float childWidth = childLayout.MeasuredWidth.Size.AsDecimal() + marginWidth;
maxWidth = Math.Max(maxWidth, childWidth);
alternativeMaxWidth = Math.Max(alternativeMaxWidth, matchWidthLocally ? marginWidth : childWidth);
allFillParent = (allFillParent && desiredChildWidth == LayoutParamPolicies.MatchParent);
} // for loop
}
else
{
alternativeMaxWidth = Math.Max(alternativeMaxWidth, weightedMaxWidth);
}
if (!allFillParent && widthMode != MeasureSpecification.ModeType.Exactly)
{
maxWidth = alternativeMaxWidth;
}
maxWidth += (Owner.WidthSpecification == LayoutParamPolicies.WrapContent)?(Padding.Start + Padding.End):0;
maxWidth = Math.Max(maxWidth, SuggestedMinimumWidth.AsRoundedValue());
heightSizeAndState.State = childState.heightState;
SetMeasuredDimensions(ResolveSizeAndState(new LayoutLength(maxWidth + Padding.Top + Padding.Bottom), widthMeasureSpec, childState.widthState),
heightSizeAndState);
if (matchWidth)
{
ForceUniformWidth(heightMeasureSpec);
}
} // MeasureVertical
private void MeasureHorizontal(MeasureSpecification widthMeasureSpec, MeasureSpecification heightMeasureSpec)
{
var widthMode = widthMeasureSpec.Mode;
var heightMode = heightMeasureSpec.Mode;
bool isExactly = (widthMode == MeasureSpecification.ModeType.Exactly);
bool matchHeight = false;
bool allFillParent = true;
float maxHeight = 0.0f;
float alternativeMaxHeight = 0.0f;
float weightedMaxHeight = 0.0f;
float totalWeight = 0.0f;
// Reset measure variables
_totalLength = 0.0f;
float usedExcessSpace = 0.0f;
HeightAndWidthState childState = new HeightAndWidthState(MeasuredSize.StateType.MeasuredSizeOK,
MeasuredSize.StateType.MeasuredSizeOK);
// 1st phase:
// We cycle through all children and measure children with weight 0 (non weighted children) according to their specs
// to accumulate total used space in totalLength based on measured sizes and margins.
// Weighted children are not measured at this phase.
// Available space for weighted children will be calculated in the phase 2 based on totalLength value.
// Max height of children is stored.
for (int i = 0; i < LayoutChildren.Count; i++)
{
LayoutItem childLayout = LayoutChildren[i];
if (childLayout.Owner.ExcludeLayouting)
{
MeasureChildWithoutPadding(childLayout, widthMeasureSpec, heightMeasureSpec);
continue;
}
int childDesiredHeight = childLayout.Owner.HeightSpecification;
float childWeight = childLayout.Owner.Weight;
Extents childMargin = childLayout.Margin;
totalWeight += childWeight;
bool useExcessSpace = (childLayout.Owner.WidthSpecification == 0) && (childWeight > 0);
if (isExactly && useExcessSpace)
{
// Children to be laid out with excess space can be measured later
_totalLength = Math.Max(_totalLength, (_totalLength + childMargin.Start + childMargin.End));
}
else
{
if (useExcessSpace)
{
// Parent is not defiend!!!
// The widthMode is either Unspecified or AtMost, and
// this child is only laid out using excess space. Measure
// using WrapContent so that we can find out the view's
// optimal width.
MeasureSpecification childWidthMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(
new LayoutLength(widthMeasureSpec.Size - (childLayout.Margin.Start + childLayout.Margin.End)),
widthMeasureSpec.Mode),
new LayoutLength(Padding.Start + Padding.End),
new LayoutLength(LayoutParamPolicies.WrapContent));
MeasureSpecification childHeightMeasureSpec = GetChildMeasureSpecification(
new MeasureSpecification(
new LayoutLength(heightMeasureSpec.Size - (childLayout.Margin.Top + childLayout.Margin.Bottom)),
heightMeasureSpec.Mode),
new LayoutLength(Padding.Top + Padding.Bottom),
new LayoutLength(childDesiredHeight));
childLayout.Measure(childWidthMeasureSpec, childHeightMeasureSpec);
usedExcessSpace += childLayout.MeasuredWidth.Size.AsDecimal();
}
else
{
MeasureChildWithMargins(childLayout, widthMeasureSpec, new LayoutLength(0), heightMeasureSpec, new LayoutLength(0));
}
LayoutLength childWidth = childLayout.MeasuredWidth.Size;
LayoutLength length = childWidth + childMargin.Start + childMargin.End;
if (isExactly)
{
_totalLength += length.AsDecimal();
}
else
{
_totalLength = Math.Max(_totalLength, _totalLength + length.AsDecimal() + (i < LayoutChildren.Count - 1 ? CellPadding.Width : 0));
}
}
bool matchHeightLocally = false;
if (heightMode != MeasureSpecification.ModeType.Exactly && childDesiredHeight == LayoutParamPolicies.MatchParent)
{
// A child has set to MatchParent on it's height.
// Will have to re-measure at least this child when we know exact height.
matchHeight = true;
matchHeightLocally = true;
}
float marginHeight = childMargin.Top + childMargin.Bottom;
float childHeight = childLayout.MeasuredHeight.Size.AsDecimal() + marginHeight;
if (childLayout.MeasuredWidth.State == MeasuredSize.StateType.MeasuredSizeTooSmall)
{
childState.widthState = MeasuredSize.StateType.MeasuredSizeTooSmall;
}
if (childLayout.MeasuredHeight.State == MeasuredSize.StateType.MeasuredSizeTooSmall)
{
childState.heightState = MeasuredSize.StateType.MeasuredSizeTooSmall;
}
maxHeight = Math.Max(maxHeight, childHeight);
allFillParent = (allFillParent && childDesiredHeight == LayoutParamPolicies.MatchParent);
if (childWeight > 0)
{
// Heights of weighted Views are invalid if we end up remeasuring, so store them separately.
weightedMaxHeight = Math.Max(weightedMaxHeight, matchHeightLocally ? marginHeight : childHeight);
}
else
{
alternativeMaxHeight = Math.Max(alternativeMaxHeight, matchHeightLocally ? marginHeight : childHeight);
}
} // foreach
float widthSize = _totalLength;
widthSize = Math.Max(widthSize, SuggestedMinimumWidth.AsDecimal());
MeasuredSize widthSizeAndState = ResolveSizeAndState(new LayoutLength(widthSize + Padding.Start + Padding.End), widthMeasureSpec, MeasuredSize.StateType.MeasuredSizeOK);
widthSize = widthSizeAndState.Size.AsDecimal();
// 2nd phase:
// Expand children with weight to take up available space
// We cycle through weighted children now (children with weight > 0).
// The children are measured with exact size equal to their share of the available space based on their weights.
// _totalLength is updated to include weighted children measured sizes.
float remainingExcess = widthSize - _totalLength + usedExcessSpace - (Padding.Start + Padding.End);
if (remainingExcess != 0 && totalWeight > 0)
{
float remainingWeight = totalWeight;
maxHeight = 0;
_totalLength = 0;
int numberOfChildren = LayoutChildren.Count;
for (int i = 0; i < numberOfChildren; ++i)
{
LayoutItem childLayout = LayoutChildren[i];
if (childLayout.Owner.ExcludeLayouting)
{
continue;
}
float desiredChildHeight = childLayout.Owner.HeightSpecification;
float childWeight = childLayout.Owner.Weight;
Extents childMargin = childLayout.Margin;
if (childWeight > 0)
{
MeasureWeightedChild(childLayout, remainingExcess, remainingWeight, childWeight,
widthMeasureSpec, heightMeasureSpec, childState,
Orientation.Horizontal);
}
float length = childLayout.MeasuredWidth.Size.AsDecimal() + childMargin.Start + childMargin.End;
float cellPadding = i < numberOfChildren - 1 ? CellPadding.Width : 0;
if (isExactly)
{
_totalLength += length;
}
else
{
float totalLength = _totalLength;
_totalLength = Math.Max(_totalLength, _totalLength + length + cellPadding);
}
bool matchHeightLocally = (heightMode != MeasureSpecification.ModeType.Exactly) && (desiredChildHeight == LayoutParamPolicies.MatchParent);
float marginHeight = childMargin.Top + childMargin.Bottom;
float childHeight = childLayout.MeasuredHeight.Size.AsDecimal() + marginHeight;
maxHeight = Math.Max(maxHeight, childHeight);
alternativeMaxHeight = Math.Max(alternativeMaxHeight, matchHeightLocally ? marginHeight : childHeight);
allFillParent = (allFillParent && desiredChildHeight == LayoutParamPolicies.MatchParent);
} // for loop
}
else
{
// No excess space or no weighted children
alternativeMaxHeight = Math.Max(alternativeMaxHeight, weightedMaxHeight);
}
if (!allFillParent && heightMode != MeasureSpecification.ModeType.Exactly)
{
maxHeight = alternativeMaxHeight;
}
// Padding should be concerned when specification is Wrapcontent.
maxHeight += (Owner.HeightSpecification == LayoutParamPolicies.WrapContent) ? (Padding.Top + Padding.Bottom) : 0;
maxHeight = Math.Max(maxHeight, SuggestedMinimumHeight.AsRoundedValue());
widthSizeAndState.State = childState.widthState;
SetMeasuredDimensions(widthSizeAndState,
ResolveSizeAndState(new LayoutLength(maxHeight), heightMeasureSpec, childState.heightState));
if (matchHeight)
{
ForceUniformHeight(widthMeasureSpec);
}
} // MeasureHorizontal
