protected override void performLayout()
{
BoxConstraints constraints = this.constraints;
bool hasLeading = leading != null;
bool hasSubtitle = subtitle != null;
bool hasTrailing = trailing != null;
bool isTwoLine = !isThreeLine && hasSubtitle;
bool isOneLine = !isThreeLine && !hasSubtitle;
BoxConstraints maxIconHeightConstrains = new BoxConstraints(
maxHeight: isDense ? 48.0f : 56.0f
);
BoxConstraints looseConstraints = constraints.loosen();
BoxConstraints iconConstraints = looseConstraints.enforce(maxIconHeightConstrains);
float tileWidth = looseConstraints.maxWidth;
Size leadingSize = _layoutBox(leading, iconConstraints);
Size trailingSize = _layoutBox(trailing, iconConstraints);
D.assert(
tileWidth != leadingSize.width,
() => "Leading widget consumes entire width. Please use a sized widget."
);
D.assert(
tileWidth != trailingSize.width,
() => "Trailing widget consumes entire width. Please use a sized widget."
);
float titleStart = hasLeading
? Mathf.Max(_minLeadingWidth, leadingSize.width) + _horizontalTitleGap
: 0.0f;
BoxConstraints textConstraints = looseConstraints.tighten(
width: tileWidth - titleStart - (hasTrailing ? trailingSize.width + _horizontalTitleGap : 0.0f));
Size titleSize = _layoutBox(title, textConstraints);
Size subtitleSize = _layoutBox(subtitle, textConstraints);
float titleBaseline = 0.0f;
float subtitleBaseline = 0.0f;
if (isTwoLine)
{
titleBaseline = isDense ? 28.0f : 32.0f;
subtitleBaseline = isDense ? 48.0f : 52.0f;
}
else if (isThreeLine)
{
titleBaseline = isDense ? 22.0f : 28.0f;
subtitleBaseline = isDense ? 42.0f : 48.0f;
}
else
{
D.assert(isOneLine);
}
float defaultTileHeight = _defaultTileHeight;
float tileHeight = 0.0f;
float titleY = 0.0f;
float subtitleY = 0.0f;
if (!hasSubtitle)
{
tileHeight = Mathf.Max(defaultTileHeight, titleSize.height + 2.0f * _minVerticalPadding);
titleY = (tileHeight - titleSize.height) / 2.0f;
}
else
{
D.assert(subtitleBaselineType != null);
titleY = titleBaseline - _boxBaseline(title, titleBaselineType);
subtitleY = subtitleBaseline -
_boxBaseline(subtitle, subtitleBaselineType ?? TextBaseline.alphabetic);
tileHeight = defaultTileHeight;
float titleOverlap = titleY + titleSize.height - subtitleY;
if (titleOverlap > 0.0f)
{
titleY -= titleOverlap / 2.0f;
subtitleY += titleOverlap / 2.0f;
}
if (titleY < _minVerticalPadding ||
(subtitleY + subtitleSize.height + _minVerticalPadding) > tileHeight)
{
tileHeight = titleSize.height + subtitleSize.height + 2.0f * _minVerticalPadding;
titleY = _minVerticalPadding;
subtitleY = titleSize.height + _minVerticalPadding;
}
}
float leadingY;
float trailingY;
if (tileHeight > 72.0f)
{
leadingY = 16.0f;
trailingY = 16.0f;
}
else
{
leadingY = Mathf.Min((tileHeight - leadingSize.height) / 2.0f, 16.0f);
trailingY = (tileHeight - trailingSize.height) / 2.0f;
}
if (hasLeading)
{
_positionBox(leading, new Offset(0.0f, leadingY));
}
_positionBox(title, new Offset(titleStart, titleY));
if (hasSubtitle)
{
_positionBox(subtitle, new Offset(titleStart, subtitleY));
}
if (hasTrailing)
{
_positionBox(trailing, new Offset(tileWidth - trailingSize.width, trailingY));
}
size = constraints.constrain(new Size(tileWidth, tileHeight));
D.assert(size.width == constraints.constrainWidth(tileWidth));
D.assert(size.height == constraints.constrainHeight(tileHeight));
}
protected override void performLayout()
{
BoxConstraints constraints = this.constraints;
_resolve();
D.assert(_resolvedAlignment != null);
_hasVisualOverflow = false;
bool hasNonPositionedChildren = false;
if (childCount == 0)
{
size = constraints.biggest;
D.assert(size.isFinite);
return;
}
float width = constraints.minWidth;
float height = constraints.minHeight;
BoxConstraints nonPositionedConstraints = null;
switch (fit)
{
case StackFit.loose:
nonPositionedConstraints = constraints.loosen();
break;
case StackFit.expand:
nonPositionedConstraints = BoxConstraints.tight(constraints.biggest);
break;
case StackFit.passthrough:
nonPositionedConstraints = constraints;
break;
}
D.assert(nonPositionedConstraints != null);
RenderBox child = firstChild;
while (child != null)
{
StackParentData childParentData = child.parentData as StackParentData;
D.assert(childParentData != null);
if (!childParentData.isPositioned)
{
hasNonPositionedChildren = true;
child.layout(nonPositionedConstraints, parentUsesSize: true);
Size childSize = child.size;
width = Mathf.Max(width, childSize.width);
height = Mathf.Max(height, childSize.height);
}
child = childParentData.nextSibling;
}
if (hasNonPositionedChildren)
{
size = new Size(width, height);
D.assert(size.width == constraints.constrainWidth(width));
D.assert(size.height == constraints.constrainHeight(height));
}
else
{
size = constraints.biggest;
}
D.assert(size.isFinite);
child = firstChild;
while (child != null)
{
StackParentData childParentData = child.parentData as StackParentData;
if (!childParentData.isPositioned)
{
childParentData.offset = _resolvedAlignment.alongOffset(size - child.size as Offset);
}
else
{
_hasVisualOverflow = layoutPositionedChild(child, childParentData, size, _resolvedAlignment) || _hasVisualOverflow;
}
D.assert(child.parentData == childParentData);
child = childParentData.nextSibling;
}
}