isRepaintBoundary property Null safety
Whether this render object repaints separately from its parent.
Override this in subclasses to indicate that instances of your class ought to repaint independently. For example, render objects that repaint frequently might want to repaint themselves without requiring their parent to repaint.
If this getter returns true, the paintBounds are applied to this object and all descendants. The framework invokes RenderObject.updateCompositedLayer to create an OffsetLayer and assigns it to the layer field. Render objects that declare themselves as repaint boundaries must not replace the layer created by the framework.
If the value of this getter changes, markNeedsCompositingBitsUpdate must be called.
See RepaintBoundary for more information about how repaint boundaries function.
@override bool get isRepaintBoundary => true;