[escher/scroll_view] Simplify subviews management

escher/include/escher/scroll_view.h

@@ -28,8 +28,11 @@ public:
   class Decorator {
   public:
     Decorator();
-    int numberOfIndicators();
-    View * indicatorAtIndex(int index);
+    int numberOfIndicators() { return 2; }
+    View * indicatorAtIndex(int index) {
+      assert(0 < index && index <= numberOfIndicators());
+      return &m_verticalBar + (index-1);
+    }
     void layoutIndicators(KDSize content, KDPoint offset, KDSize frame);
     ScrollViewVerticalBar * verticalBar() { return &m_verticalBar; }
     ScrollViewHorizontalBar * horizontalBar() { return &m_horizontalBar; }

escher/src/scroll_view.cpp

@@ -152,24 +152,6 @@ ScrollView::Decorator::Decorator() :
 {
 }
 
-int ScrollView::Decorator::numberOfIndicators() {
-  return m_verticalBar.visible() + m_horizontalBar.visible();
-}
-
-View * ScrollView::Decorator::indicatorAtIndex(int index) {
-  switch (index) {
-    case 1:
-      if (m_horizontalBar.visible()) {
-        return &m_horizontalBar;
-      } else {
-        return &m_verticalBar;
-      }
-    case 2:
-      return &m_verticalBar;
-  }
-  return nullptr;
-}
-
 void ScrollView::Decorator::layoutIndicators(KDSize content, KDPoint offset, KDSize frame) {
   m_horizontalBar.update(
     content.width(),

escher/src/scroll_view_indicator.cpp

@@ -32,6 +32,9 @@ void ScrollViewBar::update(KDCoordinate totalContentLength, KDCoordinate content
 }
 
 void ScrollViewHorizontalBar::drawRect(KDContext * ctx, KDRect rect) const {
+  if (!visible()) {
+    return;
+  }
   ctx->fillRect(
     KDRect(
       m_margin, (m_frame.height() - k_indicatorThickness)/2,
@@ -49,6 +52,9 @@ void ScrollViewHorizontalBar::drawRect(KDContext * ctx, KDRect rect) const {
 }
 
 void ScrollViewVerticalBar::drawRect(KDContext * ctx, KDRect rect) const {
+  if (!visible()) {
+    return;
+  }
   ctx->fillRect(
     KDRect(
       (m_frame.width() - k_indicatorThickness)/2, m_margin,