handlesVisible property
Whether selection handles are visible.
Set to false if you want to hide the handles. Use this property to show or hide the handle without rebuilding them.
If this method is called while the SchedulerBinding.schedulerPhase is SchedulerPhase.persistentCallbacks, i.e. during the build, layout, or paint phases (see WidgetsBinding.drawFrame), then the update is delayed until the post-frame callbacks phase. Otherwise the update is done synchronously. This means that it is safe to call during builds, but also that if you do call this during a build, the UI will not update until the next frame (i.e. many milliseconds later).
Defaults to false.
Implementation
bool handlesVisible = false;