dispose method
Disposes this object and release resources.
Implementation
void dispose() {
// TODO(polina-c): stop duplicating code across disposables
// https://github.com/flutter/flutter/issues/137435
if (kFlutterMemoryAllocationsEnabled) {
FlutterMemoryAllocations.instance.dispatchObjectDisposed(object: this);
}
_selectionOverlay.dispose();
renderObject.selectionStartInViewport.removeListener(_updateTextSelectionOverlayVisibilities);
renderObject.selectionEndInViewport.removeListener(_updateTextSelectionOverlayVisibilities);
_effectiveToolbarVisibility.dispose();
_effectiveStartHandleVisibility.dispose();
_effectiveEndHandleVisibility.dispose();
hideToolbar();
}