text: #include <escher/scrollable_view.h>
  #include <escher/metric.h>
  #include <assert.h>
  #include <algorithm>
  
  namespace Escher {
  
  ScrollableView::ScrollableView(Responder * parentResponder, View * view, ScrollViewDataSource * dataSource) :
    Responder(parentResponder),
    ScrollView(view, dataSource)
  {
    setDecoratorType(ScrollView::Decorator::Type::None);
  }
  
  bool ScrollableView::handleEvent(Ion::Events::Event event) {
    KDPoint translation = KDPointZero;
    KDCoordinate scrollStep = Ion::Events::repetitionFactor() * Metric::ScrollStep;
    if (event == Ion::Events::Left) {
      KDCoordinate movementToEdge = contentOffset().x();
      if (movementToEdge > 0) {
        translation = KDPoint(-std::min(scrollStep, movementToEdge), 0);
      }
    }
    if (event == Ion::Events::Right) {
      KDCoordinate movementToEdge = minimalSizeForOptimalDisplay().width() - bounds().width() - contentOffset().x();
      if (movementToEdge > 0) {
        translation = KDPoint(std::min(scrollStep, movementToEdge), 0);
      }
    }
    if (event == Ion::Events::Up) {
      KDCoordinate movementToEdge = contentOffset().y();
      if (movementToEdge > 0) {
        translation = KDPoint(0, -std::min(scrollStep, movementToEdge));
      }
    }
    if (event == Ion::Events::Down) {
      KDCoordinate movementToEdge = minimalSizeForOptimalDisplay().height() - bounds().height() - contentOffset().y();
      if (movementToEdge > 0) {
        translation = KDPoint(0, std::min(scrollStep, movementToEdge));
      }
    }
    if (translation != KDPointZero) {
      setContentOffset(contentOffset().translatedBy(translation));
      return true;
    }
    return false;
  }
  
  void ScrollableView::reloadScroll(bool forceReLayout) {
    setContentOffset(KDPointZero, forceReLayout);
  }
  
  KDSize ScrollableView::contentSize() const {
    KDSize viewSize = ScrollView::contentSize();
    KDCoordinate viewWidth = std::max(viewSize.width(), maxContentWidthDisplayableWithoutScrolling());
    KDCoordinate viewHeight = std::max(viewSize.height(), maxContentHeightDisplayableWithoutScrolling());
    return KDSize(viewWidth, viewHeight);
  }
  
  }
  