Container
Base for child-Control layout algorithms.
Container manages direct child Controls. An ordinary intermediate Entity is not a layout item; TopLevel and hidden items are excluded from ordinary sorting. The base Container without a script supplies no useful placement: choose a concrete Box/Grid/Panel or implement your own algorithm.
QueueSort defers a pass and coalesces requests. A pass sends NotificationPreSortChildren and PreSortChildren before NotificationSortChildren and SortChildren. This is not a global completion signal for the entire layout tree. Measure final rectangles after the necessary passes.
For custom layout, FitChildInRect requires a direct child and a rectangle local to the container. It applies constraints/SizeFlags and resets Rotation to 0 and Scale to Vector2.One. To preserve animated transforms across layout passes, put animated content in an inner Control instead of animating the direct child.
_GetAllowedSizeFlagsHorizontal/Vertical are callbacks listing allowed flags for a custom container. Their generated base returns null; a direct call does not query a child’s current flags. AccessibilityRegion changes accessibility semantics rather than geometry or focus.
Declarations checked against C# SDK 1.0.0. Expand a name to see declarations and documentation.
Constructors1
ContainerConstructor
public Container();Creates a base for custom layout; prefer a concrete container without a custom placement implementation.
Properties1
AccessibilityRegionProperty
public bool AccessibilityRegion { get; set; }Accessibility-region semantic flag, false by default. Does not change geometry/focus routing; test screen-reader integration separately.
Methods6
FitChildInRectvoid
public void FitChildInRect(Control child, Rect2 rect);Fits only a direct child Control into a local area using constraints/SizeFlags. Resets Rotation = 0 and Scale = One. Use in custom layout rather than fighting a concrete container’s layout.
| Name | Type | Default |
|---|---|---|
child | Control | — |
rect | Rect2 | — |
childNonnull direct child Control of this container rather than another container’s child or a distant descendant.
rectRectangle with nonnegative dimensions in container-local coordinates; the result also follows constraints and SizeFlags.
IsAccessibilityRegionbool
public bool IsAccessibilityRegion();Accessibility-region semantic flag, false by default. Does not change geometry/focus routing; test screen-reader integration separately.
boolCurrent flag bool rather than a screen-reader test result.
QueueSortvoid
public void QueueSort();Requests a deferred pass while inside the tree; repeated requests coalesce. Does not lay out outside the tree. Neither synchronous recalculation nor a manual Position reset.
SetAccessibilityRegionvoid
public void SetAccessibilityRegion(bool region);Accessibility-region semantic flag, false by default. Does not change geometry/focus routing; test screen-reader integration separately.
| Name | Type | Default |
|---|---|---|
region | bool | — |
regiontrue for an accessibility-region role, false for an ordinary container.
_GetAllowedSizeFlagsHorizontalint[]
public virtual int[] _GetAllowedSizeFlagsHorizontal();Callback listing allowed horizontal SizeFlags values for a custom container. Return enum-value int[] rather than a particular child’s flags. Generated base returns null.
int[]Implementation int[] of values; generated base returns null.
_GetAllowedSizeFlagsVerticalint[]
public virtual int[] _GetAllowedSizeFlagsVertical();Callback listing a custom container’s allowed vertical SizeFlags values. Generated base returns null; not a getter for actual layout.
int[]Implementation int[] of values; generated base returns null.
Signals and events2
PreSortChildrenEvent
public event Action PreSortChildren;Signal after NotificationPreSortChildren and before NotificationSortChildren. Suitable for layout preparation rather than reading final dimensions of the whole tree.
SortChildrenEvent
public event Action SortChildren;Signal after this container’s NotificationSortChildren. Custom placement can use FitChildInRect. Other hierarchy levels may still relayout.
Fields and constants2
NotificationPreSortChildrenField
public const long NotificationPreSortChildren = 50;Notification code before sorting children, for a custom container _Notification. PreSortChildren follows it.
NotificationSortChildrenField
public const long NotificationSortChildren = 51;Notification code for child placement during a sort pass. SortChildren follows the notification. Not completion of the whole UI tree.