public void positionChild(object childId, Offset offset)
{
RenderBox child = this._idToChild[childId];
D.assert(() => {
if (child == null)
{
throw new UIWidgetsError(
$"The {this} custom multichild layout delegate tried to position out a non-existent child:\n" +
$"There is no child with the id \"{childId}\"."
);
}
if (offset == null)
{
throw new UIWidgetsError(
$"The {this} custom multichild layout delegate provided a null position for the child with id \"{childId}\"."
);
}
return(true);
});
MultiChildLayoutParentData childParentData = (MultiChildLayoutParentData)child.parentData;
childParentData.offset = offset;
}
internal void _callPerformLayout(Size size, RenderBox firstChild)
{
Dictionary <object, RenderBox> previousIdToChild = this._idToChild;
HashSet <RenderBox> debugPreviousChildrenNeedingLayout = null;
D.assert(() => {
debugPreviousChildrenNeedingLayout = this._debugChildrenNeedingLayout;
this._debugChildrenNeedingLayout = new HashSet <RenderBox>();
return(true);
});
try {
this._idToChild = new Dictionary <object, RenderBox>();
RenderBox child = firstChild;
while (child != null)
{
MultiChildLayoutParentData childParentData = (MultiChildLayoutParentData)child.parentData;
D.assert(() => {
if (childParentData.id == null)
{
throw new UIWidgetsError(
"The following child has no ID:\n" +
$" {child}\n" +
"Every child of a RenderCustomMultiChildLayoutBox must have an ID in its parent data."
);
}
return(true);
});
this._idToChild[childParentData.id] = child;
D.assert(() => {
this._debugChildrenNeedingLayout.Add(child);
return(true);
});
child = childParentData.nextSibling;
}
this.performLayout(size);
D.assert(() => {
if (this._debugChildrenNeedingLayout.isNotEmpty())
{
if (this._debugChildrenNeedingLayout.Count > 1)
{
throw new UIWidgetsError(
$"The $this custom multichild layout delegate forgot to lay out the following children:\n" +
$" {string.Join("\n ", this._debugChildrenNeedingLayout.Select(this._debugDescribeChild))}\n" +
"Each child must be laid out exactly once."
);
}
else
{
throw new UIWidgetsError(
$"The $this custom multichild layout delegate forgot to lay out the following child:\n" +
$" {this._debugDescribeChild(this._debugChildrenNeedingLayout.First())}\n" +
"Each child must be laid out exactly once."
);
}
}
return(true);
});
}
finally {
this._idToChild = previousIdToChild;
D.assert(() => {
this._debugChildrenNeedingLayout = debugPreviousChildrenNeedingLayout;
return(true);
});
}
}
string _debugDescribeChild(RenderBox child)
{
MultiChildLayoutParentData childParentData = (MultiChildLayoutParentData)child.parentData;
return($"{childParentData.id}: {child}");
}
internal void _callPerformLayout(Size size, RenderBox firstChild)
{
Dictionary <object, RenderBox> previousIdToChild = _idToChild;
HashSet <RenderBox> debugPreviousChildrenNeedingLayout = null;
D.assert(() => {
debugPreviousChildrenNeedingLayout = _debugChildrenNeedingLayout;
_debugChildrenNeedingLayout = new HashSet <RenderBox>();
return(true);
});
try {
_idToChild = new Dictionary <object, RenderBox>();
RenderBox child = firstChild;
while (child != null)
{
MultiChildLayoutParentData childParentData = (MultiChildLayoutParentData)child.parentData;
D.assert(() => {
if (childParentData.id == null)
{
throw new UIWidgetsError(new List <DiagnosticsNode> {
new ErrorSummary("Every child of a RenderCustomMultiChildLayoutBox must have an ID in its parent data."),
child.describeForError("The following child has no ID")
});
}
return(true);
});
_idToChild[childParentData.id] = child;
D.assert(() => {
_debugChildrenNeedingLayout.Add(child);
return(true);
});
child = childParentData.nextSibling;
}
performLayout(size);
D.assert(() => {
List <DiagnosticsNode> renderBoxes = new List <DiagnosticsNode>();
foreach (var renderBox in _debugChildrenNeedingLayout)
{
renderBoxes.Add(_debugDescribeChild(renderBox));
}
if (_debugChildrenNeedingLayout.isNotEmpty())
{
throw new UIWidgetsError(new List <DiagnosticsNode> {
new ErrorSummary("Each child must be laid out exactly once."),
new DiagnosticsBlock(
name: "The $this custom multichild layout delegate forgot " +
"to lay out the following child(ren)",
properties: renderBoxes,
style: DiagnosticsTreeStyle.whitespace
)
});
}
return(true);
});
}
finally {
_idToChild = previousIdToChild;
D.assert(() => {
_debugChildrenNeedingLayout = debugPreviousChildrenNeedingLayout;
return(true);
});
}
}
DiagnosticsNode _debugDescribeChild(RenderBox child)
{
MultiChildLayoutParentData childParentData = (MultiChildLayoutParentData)child.parentData;
return(new DiagnosticsProperty <RenderBox>($"{childParentData.id}", child));
}
