[escher/scroll_view] Fix virtuality issues of layoutSubviews

Method contentSize() made virtual and overridden by ScrollableView
so that ScrollableView and TableView do not need to setSize themselves
and that setSize/setFrame is not called twice over m_contentView.

escher/include/escher/scroll_view.h

@@ -92,7 +92,7 @@ protected:
   }
   KDRect visibleContentRect();
   void layoutSubviews() override;
-  KDSize contentSize();
+  virtual KDSize contentSize() const { return m_contentView->minimalSizeForOptimalDisplay(); }
 #if ESCHER_VIEW_LOGGING
   virtual const char * className() const override;
   virtual void logAttributes(std::ostream &os) const override;

escher/include/escher/scrollable_view.h

@@ -11,7 +11,7 @@ public:
   bool handleEvent(Ion::Events::Event event) override;
   void reloadScroll(bool forceRelayout = false);
 protected:
-  void layoutSubviews() override;
+  KDSize contentSize() const override;
   KDPoint m_manualScrollingOffset;
 };
 

escher/include/escher/table_view.h

@@ -38,12 +38,12 @@ protected:
     void scrollToCell(int i, int j) const;
     void reloadCellAtLocation(int i, int j);
     HighlightCell * cellAtLocation(int i, int j);
-    void resizeToFitContent();
     TableViewDataSource * dataSource();
     int rowsScrollingOffset() const;
     int columnsScrollingOffset() const;
     int numberOfDisplayableRows() const;
     int numberOfDisplayableColumns() const;
+    void layoutSubviews() override;
   protected:
 #if ESCHER_VIEW_LOGGING
     const char * className() const override;
@@ -54,7 +54,6 @@ protected:
 
     int numberOfSubviews() const override;
     View * subviewAtIndex(int index) override;
-    void layoutSubviews() override;
 
     /* realCellWidth enables to handle list view for which
      * TableViewDataSource->cellWidht = 0 */

escher/src/scroll_view.cpp

@@ -104,10 +104,8 @@ KDRect ScrollView::visibleContentRect() {
 }
 
 void ScrollView::layoutSubviews() {
-  // Layout contentView
-  // We're only re-positionning the contentView, not modifying its size.
   KDPoint absoluteOffset = contentOffset().opposite().translatedBy(KDPoint(m_leftMargin, m_topMargin));
-  KDRect contentFrame = KDRect(absoluteOffset, m_contentView->bounds().size());
+  KDRect contentFrame = KDRect(absoluteOffset, contentSize());
   m_contentView->setFrame(contentFrame);
   KDSize content(
     m_contentView->bounds().width() + m_leftMargin + m_rightMargin,
@@ -116,10 +114,6 @@ void ScrollView::layoutSubviews() {
   decorator()->layoutIndicators(content, contentOffset(), m_frame.size());
 }
 
-KDSize ScrollView::contentSize() {
-  return m_contentView->minimalSizeForOptimalDisplay();
-}
-
 void ScrollView::setContentOffset(KDPoint offset, bool forceRelayout) {
   if (m_dataSource->setOffset(offset) || forceRelayout) {
     layoutSubviews();

escher/src/scrollable_view.cpp

@@ -50,10 +50,9 @@ void ScrollableView::reloadScroll(bool forceReLayout) {
   setContentOffset(m_manualScrollingOffset, forceReLayout);
 }
 
-void ScrollableView::layoutSubviews() {
-  KDSize viewSize = contentSize();
-  KDCoordinate viewWidth = max(viewSize.width(), bounds().width() - leftMargin() - rightMargin());
-  KDCoordinate viewHeight = max(viewSize.height(), bounds().height() - topMargin() - bottomMargin());
-  m_contentView->setSize(KDSize(viewWidth, viewHeight));
-  ScrollView::layoutSubviews();
+KDSize ScrollableView::contentSize() const {
+  KDSize viewSize = ScrollView::contentSize();
+  KDCoordinate viewWidth = max(viewSize.width(), maxContentWidthDisplayableWithoutScrolling());
+  KDCoordinate viewHeight = max(viewSize.height(), maxContentHeightDisplayableWithoutScrolling());
+  return KDSize(viewWidth, viewHeight);
 }

escher/src/table_view.cpp

@@ -38,12 +38,20 @@ const char * TableView::className() const {
 #endif
 
 void TableView::layoutSubviews() {
-  // We only have to layout our contentView.
-  // We will size it here, and ScrollView::layoutSubviews will position it.
-
-  m_contentView.resizeToFitContent();
-
   ScrollView::layoutSubviews();
+  m_contentView.layoutSubviews();
+  /* FIXME:
+   * On the one hand, ScrollView::layoutSubviews()
+   * calls setFrame(...) over m_contentView,
+   * which typically calls layoutSubviews() over m_contentView.
+   * However, if the frame happens to be unchanged,
+   * setFrame(...) does not call layoutSubviews.
+   * On the other hand, calling only m_contentView.layoutSubviews()
+   * does not relayout ScrollView when the offset
+   * or the content's size changes.
+   * For those reasons, we call both of them explicitly.
+   * Finally, this solution is not optimal at all since
+   * layoutSubviews is called twice over m_contentView. */
 }
 
 void TableView::reloadCellAtLocation(int i, int j) {
@@ -75,13 +83,6 @@ KDCoordinate TableView::ContentView::columnWidth(int i) const {
   return columnWidth;
 }
 
-void TableView::ContentView::resizeToFitContent() {
-  if (!(m_tableView->bounds() == KDRectZero)) {
-    layoutSubviews();
-    setSize(KDSize(width(), height()));
-  }
-}
-
 KDCoordinate TableView::ContentView::height() const {
   return m_dataSource->cumulatedHeightFromIndex(m_dataSource->numberOfRows())+m_verticalCellOverlap;
 }