public void setChildParentData(RenderObject child, SliverConstraints constraints, SliverGeometry geometry)
{
var childParentData = (SliverPhysicalParentData)child.parentData;
switch (GrowthDirectionUtils.applyGrowthDirectionToAxisDirection(constraints.axisDirection,
constraints.growthDirection))
{
case AxisDirection.up:
childParentData.paintOffset = new Offset(0.0f,
-(geometry.scrollExtent - (geometry.paintExtent + constraints.scrollOffset)));
break;
case AxisDirection.right:
childParentData.paintOffset = new Offset(-constraints.scrollOffset, 0.0f);
break;
case AxisDirection.down:
childParentData.paintOffset = new Offset(0.0f, -constraints.scrollOffset);
break;
case AxisDirection.left:
childParentData.paintOffset =
new Offset(-(geometry.scrollExtent - (geometry.paintExtent + constraints.scrollOffset)),
0.0f);
break;
}
}
public static bool _getRightWayUp(SliverConstraints constraints)
{
D.assert(constraints != null);
bool rightWayUp = true;
switch (constraints.axisDirection)
{
case AxisDirection.up:
case AxisDirection.left:
rightWayUp = false;
break;
case AxisDirection.down:
case AxisDirection.right:
rightWayUp = true;
break;
}
switch (constraints.growthDirection)
{
case GrowthDirection.forward:
break;
case GrowthDirection.reverse:
rightWayUp = !rightWayUp;
break;
}
return(rightWayUp);
}
protected override void performLayout()
{
SliverConstraints constraints = this.constraints;
float extent = constraints.remainingPaintExtent - Mathf.Min(constraints.overlap, 0.0f);
if (child != null)
{
child.layout(constraints.asBoxConstraints(
minExtent: extent,
maxExtent: extent
));
}
float paintedChildSize = calculatePaintOffset(constraints, from: 0.0f, to: extent);
D.assert(paintedChildSize.isFinite());
D.assert(paintedChildSize >= 0.0);
geometry = new SliverGeometry(
scrollExtent: constraints.viewportMainAxisExtent,
paintExtent: paintedChildSize,
maxPaintExtent: paintedChildSize,
hasVisualOverflow: extent > constraints.remainingPaintExtent || constraints.scrollOffset > 0.0
);
if (child != null)
{
setChildParentData(child, constraints, geometry);
}
}
public float calculateCacheOffset(SliverConstraints constraints, float from, float to)
{
D.assert(from <= to);
float a = constraints.scrollOffset + constraints.cacheOrigin;
float b = constraints.scrollOffset + constraints.remainingCacheExtent;
return((to.clamp(a, b) - from.clamp(a, b)).clamp(0.0f, constraints.remainingCacheExtent));
}
public double calculateCacheOffset(SliverConstraints constraints, double from, double to)
{
D.assert(from <= to);
double a = constraints.scrollOffset + constraints.cacheOrigin;
double b = constraints.scrollOffset + constraints.remainingCacheExtent;
return((to.clamp(a, b) - from.clamp(a, b)).clamp(0.0, constraints.remainingCacheExtent));
}
protected virtual double estimateMaxScrollOffset(SliverConstraints constraints,
int firstIndex = 0,
int lastIndex = 0,
double leadingScrollOffset = 0.0,
double trailingScrollOffset = 0.0
)
{
return(this.childManager.estimateMaxScrollOffset(
constraints,
firstIndex: firstIndex,
lastIndex: lastIndex,
leadingScrollOffset: leadingScrollOffset,
trailingScrollOffset: trailingScrollOffset
));
}
protected virtual float estimateMaxScrollOffset(
SliverConstraints constraints,
int firstIndex = 0,
int lastIndex = 0,
float leadingScrollOffset = 0.0f,
float trailingScrollOffset = 0.0f
)
{
return(childManager.estimateMaxScrollOffset(
constraints,
firstIndex: firstIndex,
lastIndex: lastIndex,
leadingScrollOffset: leadingScrollOffset,
trailingScrollOffset: trailingScrollOffset
));
}
protected override void performLayout()
{
SliverConstraints constraints = this.constraints;
float extent = constraints.viewportMainAxisExtent - constraints.precedingScrollExtent;
if (child != null)
{
float childExtent = 0f;
switch (constraints.axis)
{
case Axis.horizontal:
childExtent = child.getMaxIntrinsicWidth(constraints.crossAxisExtent);
break;
case Axis.vertical:
childExtent = child.getMaxIntrinsicHeight(constraints.crossAxisExtent);
break;
}
extent = Mathf.Max(extent, childExtent);
child.layout(constraints.asBoxConstraints(
minExtent: extent,
maxExtent: extent
));
}
D.assert(extent.isFinite(), () =>
"The calculated extent for the child of SliverFillRemaining is not finite. " +
"This can happen if the child is a scrollable, in which case, the " +
"hasScrollBody property of SliverFillRemaining should not be set to " +
"false."
);
float paintedChildSize = calculatePaintOffset(constraints, from: 0.0f, to: extent);
D.assert(paintedChildSize.isFinite());
D.assert(paintedChildSize >= 0.0);
geometry = new SliverGeometry(
scrollExtent: extent,
paintExtent: paintedChildSize,
maxPaintExtent: paintedChildSize,
hasVisualOverflow: extent > constraints.remainingPaintExtent || constraints.scrollOffset > 0.0
);
if (child != null)
{
setChildParentData(child, constraints, geometry);
}
}
protected override float estimateMaxScrollOffset(SliverConstraints constraints,
int firstIndex = 0,
int lastIndex = 0,
float leadingScrollOffset = 0.0f,
float trailingScrollOffset = 0.0f
)
{
float padding = this._padding;
return(this.childManager.estimateMaxScrollOffset(
constraints,
firstIndex: firstIndex,
lastIndex: lastIndex,
leadingScrollOffset: leadingScrollOffset - padding,
trailingScrollOffset: trailingScrollOffset - padding
) + padding + padding);
}
protected override double estimateMaxScrollOffset(SliverConstraints constraints,
int firstIndex = 0,
int lastIndex = 0,
double leadingScrollOffset = 0.0,
double trailingScrollOffset = 0.0
)
{
double padding = this._padding;
return(this.childManager.estimateMaxScrollOffset(
constraints,
firstIndex: firstIndex,
lastIndex: lastIndex,
leadingScrollOffset: leadingScrollOffset - padding,
trailingScrollOffset: trailingScrollOffset - padding
) + padding + padding);
}
protected override void performLayout()
{
if (child == null)
{
geometry = SliverGeometry.zero;
return;
}
SliverConstraints constraints = this.constraints;
child.layout(constraints.asBoxConstraints(), parentUsesSize: true);
float childExtent = 0.0f;
switch (constraints.axis)
{
case Axis.horizontal:
childExtent = child.size.width;
break;
case Axis.vertical:
childExtent = child.size.height;
break;
}
float paintedChildSize = calculatePaintOffset(constraints, from: 0.0f, to: childExtent);
float cacheExtent = calculateCacheOffset(constraints, from: 0.0f, to: childExtent);
D.assert(paintedChildSize.isFinite());
D.assert(paintedChildSize >= 0.0f);
geometry = new SliverGeometry(
scrollExtent: childExtent,
paintExtent: paintedChildSize,
cacheExtent: cacheExtent,
maxPaintExtent: childExtent,
hitTestExtent: paintedChildSize,
hasVisualOverflow: childExtent > constraints.remainingPaintExtent ||
constraints.scrollOffset > 0.0f
);
setChildParentData(child, constraints, geometry);
}
protected override void performLayout()
{
SliverConstraints constraints = this.constraints;
float? maxExtent = this.maxExtent;
if (((constraints.scrollOffset < _lastActualScrollOffset) ||
(_effectiveScrollOffset < maxExtent)))
{
float delta = _lastActualScrollOffset - constraints.scrollOffset;
bool allowFloatingExpansion = constraints.userScrollDirection == ScrollDirection.forward;
if (allowFloatingExpansion)
{
if (_effectiveScrollOffset > maxExtent)
{
_effectiveScrollOffset = maxExtent ?? 0.0f;
}
}
else
{
if (delta > 0.0f)
{
delta = 0.0f;
}
}
_effectiveScrollOffset =
(_effectiveScrollOffset - delta).clamp(0.0f, constraints.scrollOffset);
}
else
{
_effectiveScrollOffset = constraints.scrollOffset;
}
bool overlapsContent = _effectiveScrollOffset < constraints.scrollOffset;
layoutChild(
_effectiveScrollOffset,
maxExtent ?? 0.0f,
overlapsContent: overlapsContent
);
_childPosition = updateGeometry();
_lastActualScrollOffset = constraints.scrollOffset;
}
protected override void performLayout()
{
SliverConstraints constraints = this.constraints;
float? maxExtent = this.maxExtent;
bool overlapsContent = constraints.overlap > 0.0f;
layoutChild(constraints.scrollOffset, maxExtent ?? 0.0f, overlapsContent: overlapsContent);
float effectiveRemainingPaintExtent = Mathf.Max(0, constraints.remainingPaintExtent - constraints.overlap);
float?layoutExtent = (maxExtent - constraints.scrollOffset)?.clamp(0.0f, effectiveRemainingPaintExtent);
float stretchOffset = stretchConfiguration != null?
constraints.overlap.abs() :
0.0f;
geometry = new SliverGeometry(
scrollExtent: maxExtent ?? 0.0f,
paintOrigin: constraints.overlap,
paintExtent: Mathf.Min(childExtent, effectiveRemainingPaintExtent),
layoutExtent: layoutExtent,
maxPaintExtent: (maxExtent ?? 0.0f) + stretchOffset,
maxScrollObstructionExtent: minExtent ?? 0.0f,
cacheExtent: layoutExtent > 0.0f ? -constraints.cacheOrigin + layoutExtent : layoutExtent,
hasVisualOverflow: true
);
}
protected override void performLayout()
{
SliverConstraints constraints = this.constraints;
childManager.didStartLayout();
childManager.setDidUnderflow(false);
float itemExtent = this.itemExtent;
float scrollOffset = constraints.scrollOffset + constraints.cacheOrigin;
D.assert(scrollOffset >= 0.0);
float remainingExtent = constraints.remainingCacheExtent;
D.assert(remainingExtent >= 0.0);
float targetEndScrollOffset = scrollOffset + remainingExtent;
BoxConstraints childConstraints = constraints.asBoxConstraints(
minExtent: itemExtent,
maxExtent: itemExtent
);
int firstIndex = getMinChildIndexForScrollOffset(scrollOffset, itemExtent);
int?targetLastIndex = targetEndScrollOffset.isFinite()
? getMaxChildIndexForScrollOffset(targetEndScrollOffset, itemExtent)
: (int?)null;
if (firstChild != null)
{
int leadingGarbage = _calculateLeadingGarbage(firstIndex);
int trailingGarbage = targetLastIndex == null ? 0: _calculateTrailingGarbage(targetLastIndex.Value);
collectGarbage(leadingGarbage, trailingGarbage);
}
else
{
collectGarbage(0, 0);
}
if (firstChild == null)
{
if (!addInitialChild(index: firstIndex,
layoutOffset: indexToLayoutOffset(itemExtent, firstIndex)))
{
float max;
if (childManager.childCount != null)
{
max = computeMaxScrollOffset(constraints, itemExtent);
}
else if (firstIndex <= 0)
{
max = 0.0f;
}
else
{
// We will have to find it manually.
int possibleFirstIndex = firstIndex - 1;
while (
possibleFirstIndex > 0 &&
!addInitialChild(
index: possibleFirstIndex,
layoutOffset: indexToLayoutOffset(itemExtent, possibleFirstIndex)
)
)
{
possibleFirstIndex -= 1;
}
max = possibleFirstIndex * itemExtent;
}
geometry = new SliverGeometry(
scrollExtent: max,
maxPaintExtent: max
);
childManager.didFinishLayout();
return;
}
}
RenderBox trailingChildWithLayout = null;
for (int index = indexOf(firstChild) - 1; index >= firstIndex; --index)
{
RenderBox child = insertAndLayoutLeadingChild(childConstraints);
if (child == null)
{
geometry = new SliverGeometry(scrollOffsetCorrection: index * itemExtent);
return;
}
var childParentData = (SliverMultiBoxAdaptorParentData)child.parentData;
childParentData.layoutOffset = indexToLayoutOffset(itemExtent, index);
D.assert(childParentData.index == index);
trailingChildWithLayout = trailingChildWithLayout ?? child;
}
if (trailingChildWithLayout == null)
{
firstChild.layout(childConstraints);
var childParentData = (SliverMultiBoxAdaptorParentData)firstChild.parentData;
childParentData.layoutOffset = indexToLayoutOffset(itemExtent, firstIndex);
trailingChildWithLayout = firstChild;
}
float estimatedMaxScrollOffset = float.PositiveInfinity;
for (int index = indexOf(trailingChildWithLayout) + 1;
targetLastIndex == null || index <= targetLastIndex;
++index)
{
RenderBox child = childAfter(trailingChildWithLayout);
if (child == null || indexOf(child) != index)
{
child = insertAndLayoutChild(childConstraints, after: trailingChildWithLayout);
if (child == null)
{
estimatedMaxScrollOffset = index * itemExtent;
break;
}
}
else
{
child.layout(childConstraints);
}
trailingChildWithLayout = child;
var childParentData = (SliverMultiBoxAdaptorParentData)child.parentData;
D.assert(childParentData.index == index);
childParentData.layoutOffset = indexToLayoutOffset(itemExtent, childParentData.index);
}
int lastIndex = indexOf(lastChild);
float leadingScrollOffset = indexToLayoutOffset(itemExtent, firstIndex);
float trailingScrollOffset = indexToLayoutOffset(itemExtent, lastIndex + 1);
D.assert(firstIndex == 0 ||
childScrollOffset(firstChild) - scrollOffset <= foundation_.precisionErrorTolerance);
D.assert(debugAssertChildListIsNonEmptyAndContiguous());
D.assert(indexOf(firstChild) == firstIndex);
D.assert(targetLastIndex == null || lastIndex <= targetLastIndex);
estimatedMaxScrollOffset = Mathf.Min(
estimatedMaxScrollOffset,
estimateMaxScrollOffset(
constraints,
firstIndex: firstIndex,
lastIndex: lastIndex,
leadingScrollOffset: leadingScrollOffset,
trailingScrollOffset: trailingScrollOffset
)
);
float paintExtent = calculatePaintOffset(
constraints,
from: leadingScrollOffset,
to: trailingScrollOffset
);
float cacheExtent = calculateCacheOffset(
constraints,
from: leadingScrollOffset,
to: trailingScrollOffset
);
float targetEndScrollOffsetForPaint =
constraints.scrollOffset + constraints.remainingPaintExtent;
int?targetLastIndexForPaint = targetEndScrollOffsetForPaint.isFinite()
? getMaxChildIndexForScrollOffset(targetEndScrollOffsetForPaint, itemExtent)
: (int?)null;
geometry = new SliverGeometry(
scrollExtent: estimatedMaxScrollOffset,
paintExtent: paintExtent,
cacheExtent: cacheExtent,
maxPaintExtent: estimatedMaxScrollOffset,
hasVisualOverflow: (targetLastIndexForPaint != null && lastIndex >= targetLastIndexForPaint) ||
constraints.scrollOffset > 0.0
);
if (estimatedMaxScrollOffset == trailingScrollOffset)
{
childManager.setDidUnderflow(true);
}
childManager.didFinishLayout();
}
protected float computeMaxScrollOffset(SliverConstraints constraints, float itemExtent)
{
return(childManager.childCount.Value * itemExtent);
}
protected override void performLayout()
{
SliverConstraints constraints = this.constraints;
D.assert(resolvedPadding != null);
float?beforePadding = this.beforePadding;
float?afterPadding = this.afterPadding;
float?mainAxisPadding = this.mainAxisPadding;
float?crossAxisPadding = this.crossAxisPadding;
if (child == null)
{
geometry = new SliverGeometry(
scrollExtent: mainAxisPadding ?? 0.0f,
paintExtent: Mathf.Min(mainAxisPadding ?? 0.0f, constraints.remainingPaintExtent),
maxPaintExtent: mainAxisPadding ?? 0.0f
);
return;
}
child.layout(
constraints.copyWith(
scrollOffset: Mathf.Max(0.0f, constraints.scrollOffset - beforePadding ?? 0.0f),
cacheOrigin: Mathf.Min(0.0f, constraints.cacheOrigin + beforePadding ?? 0.0f),
overlap: 0.0f,
remainingPaintExtent: constraints.remainingPaintExtent - calculatePaintOffset(constraints, from: 0.0f, to: beforePadding ?? 0.0f),
remainingCacheExtent: constraints.remainingCacheExtent - calculateCacheOffset(constraints, from: 0.0f, to: beforePadding ?? 0.0f),
crossAxisExtent: Mathf.Max(0.0f, constraints.crossAxisExtent - crossAxisPadding ?? 0.0f),
precedingScrollExtent: beforePadding ?? 0.0f + constraints.precedingScrollExtent
),
parentUsesSize: true
);
SliverGeometry childLayoutGeometry = child.geometry;
if (childLayoutGeometry.scrollOffsetCorrection != null)
{
geometry = new SliverGeometry(
scrollOffsetCorrection: childLayoutGeometry.scrollOffsetCorrection
);
return;
}
float beforePaddingPaintExtent = calculatePaintOffset(
constraints,
from: 0.0f,
to: beforePadding ?? 0.0f
);
float afterPaddingPaintExtent = calculatePaintOffset(
constraints,
from: beforePadding ?? 0.0f + childLayoutGeometry.scrollExtent,
to: mainAxisPadding ?? 0.0f + childLayoutGeometry.scrollExtent
);
float mainAxisPaddingPaintExtent = beforePaddingPaintExtent + afterPaddingPaintExtent;
float beforePaddingCacheExtent = calculateCacheOffset(
constraints,
from: 0.0f,
to: beforePadding ?? 0.0f
);
float afterPaddingCacheExtent = calculateCacheOffset(
constraints,
from: beforePadding ?? 0.0f + childLayoutGeometry.scrollExtent,
to: mainAxisPadding ?? 0.0f + childLayoutGeometry.scrollExtent
);
float mainAxisPaddingCacheExtent = afterPaddingCacheExtent + beforePaddingCacheExtent;
float paintExtent = Mathf.Min(
beforePaddingPaintExtent + Mathf.Max(childLayoutGeometry.paintExtent, childLayoutGeometry.layoutExtent + afterPaddingPaintExtent),
constraints.remainingPaintExtent
);
geometry = new SliverGeometry(
scrollExtent: (mainAxisPadding ?? 0.0f) + childLayoutGeometry.scrollExtent,
paintExtent: paintExtent,
layoutExtent: Mathf.Min(mainAxisPaddingPaintExtent + childLayoutGeometry.layoutExtent, paintExtent),
cacheExtent: Mathf.Min(mainAxisPaddingCacheExtent + childLayoutGeometry.cacheExtent, constraints.remainingCacheExtent),
maxPaintExtent: (mainAxisPadding ?? 0.0f) + childLayoutGeometry.maxPaintExtent,
hitTestExtent: Mathf.Max(
mainAxisPaddingPaintExtent + childLayoutGeometry.paintExtent,
beforePaddingPaintExtent + childLayoutGeometry.hitTestExtent
),
hasVisualOverflow: childLayoutGeometry.hasVisualOverflow
);
SliverPhysicalParentData childParentData = child.parentData as SliverPhysicalParentData;
switch (GrowthDirectionUtils.applyGrowthDirectionToAxisDirection(constraints.axisDirection, constraints.growthDirection))
{
case AxisDirection.up:
childParentData.paintOffset = new Offset(resolvedPadding.left, calculatePaintOffset(constraints, from: resolvedPadding.bottom + childLayoutGeometry.scrollExtent, to: resolvedPadding.bottom + childLayoutGeometry.scrollExtent + resolvedPadding.top));
break;
case AxisDirection.right:
childParentData.paintOffset = new Offset(calculatePaintOffset(constraints, from: 0.0f, to: resolvedPadding.left), resolvedPadding.top);
break;
case AxisDirection.down:
childParentData.paintOffset = new Offset(resolvedPadding.left, calculatePaintOffset(constraints, from: 0.0f, to: resolvedPadding.top));
break;
case AxisDirection.left:
childParentData.paintOffset = new Offset(calculatePaintOffset(constraints, from: resolvedPadding.right + childLayoutGeometry.scrollExtent, to: resolvedPadding.right + childLayoutGeometry.scrollExtent + resolvedPadding.left), resolvedPadding.top);
break;
}
D.assert(childParentData.paintOffset != null);
D.assert(beforePadding == this.beforePadding);
D.assert(afterPadding == this.afterPadding);
D.assert(mainAxisPadding == this.mainAxisPadding);
D.assert(crossAxisPadding == this.crossAxisPadding);
}
protected double computeMaxScrollOffset(SliverConstraints constraints, double itemExtent)
{
return(this.childManager.childCount.Value * itemExtent);
}