rebuild method

void rebuild ()

Called by the BuildOwner when BuildOwner.scheduleBuildFor has been called to mark this element dirty, by mount when the element is first built, and by update when the widget has changed.

Implementation 

void rebuild() {
  assert(_debugLifecycleState != _ElementLifecycle.initial);
  if (!_active || !_dirty)
    return;
  assert(() {
    if (debugOnRebuildDirtyWidget != null) {
      debugOnRebuildDirtyWidget(this, _debugBuiltOnce);
    }
    if (debugPrintRebuildDirtyWidgets) {
      if (!_debugBuiltOnce) {
        debugPrint('Building $this');
        _debugBuiltOnce = true;
      } else {
        debugPrint('Rebuilding $this');
      }
    }
    return true;
  }());
  assert(_debugLifecycleState == _ElementLifecycle.active);
  assert(owner._debugStateLocked);
  Element debugPreviousBuildTarget;
  assert(() {
    debugPreviousBuildTarget = owner._debugCurrentBuildTarget;
    owner._debugCurrentBuildTarget = this;
    return true;
  }());
  performRebuild();
  assert(() {
    assert(owner._debugCurrentBuildTarget == this);
    owner._debugCurrentBuildTarget = debugPreviousBuildTarget;
    return true;
  }());
  assert(!_dirty);
}