[apps] Cell heights memoized in ExprModelListCtrler, not FunctionLC

apps/shared/storage_expression_model_list_controller.cpp

@@ -6,11 +6,104 @@ namespace Shared {
 
 StorageExpressionModelListController::StorageExpressionModelListController(Responder * parentResponder, I18n::Message text) :
   ViewController(parentResponder),
-  m_addNewModel()
+  m_addNewModel(),
+  m_memoizedCellHeight {-1, -1, -1, -1, -1},
+  m_cumulatedHeightForSelectedIndex(-1)
 {
   m_addNewModel.setMessage(text);
 }
 
+void StorageExpressionModelListController::tableSelectionDidChange(int previousSelectedRow) {
+  constexpr int currentSelectedMemoizedIndex = k_memoizedCellHeightsCount/2 + 1; // Needs k_memoizedCellHeightsCount to be odd, which is static asserted in the header file
+  int currentSelectedRow = selectedRow();
+
+  // The previously selected cell's height might have changed.
+  m_memoizedCellHeight[currentSelectedMemoizedIndex] = -1;
+
+  // Update m_cumulatedHeightForSelectedIndex if we scrolled one cell up/down
+  if (currentSelectedRow == previousSelectedRow + 1) {
+    /* We selected the cell under the previous cell. Shift the memoized cell
+     * heights. */
+    for (int i = 0; i < k_memoizedCellHeightsCount - 1; i++) {
+      m_memoizedCellHeight[i] = m_memoizedCellHeight[i+1];
+    }
+    m_memoizedCellHeight[k_memoizedCellHeightsCount-1] = -1;
+    // Update m_cumulatedHeightForSelectedIndex
+    if (previousSelectedRow >= 0) {
+      m_cumulatedHeightForSelectedIndex+= memoizedRowHeight(previousSelectedRow);
+    } else {
+      assert(currentSelectedRow == 0);
+      m_cumulatedHeightForSelectedIndex = 0;
+    }
+  } else if (currentSelectedRow == previousSelectedRow - 1) {
+    /* We selected the cell above the previous cell. Shift the memoized cell
+     * heights. */
+    for (int i = k_memoizedCellHeightsCount - 1; i > 0; i--) {
+      m_memoizedCellHeight[i] = m_memoizedCellHeight[i-1];
+    }
+    m_memoizedCellHeight[0] = -1;
+    // Update m_cumulatedHeightForSelectedIndex
+    if (currentSelectedRow >= 0) {
+      m_cumulatedHeightForSelectedIndex-= memoizedRowHeight(currentSelectedRow);
+    } else {
+      m_cumulatedHeightForSelectedIndex = 0;
+    }
+  } else if (previousSelectedRow != currentSelectedRow) {
+    resetMemoization();
+  }
+}
+
+KDCoordinate StorageExpressionModelListController::memoizedRowHeight(int j) {
+  if (j < 0) {
+    return 0;
+  }
+  int currentSelectedRow = selectedRow();
+  constexpr int halfMemoizationCount = k_memoizedCellHeightsCount/2;
+  if (j >= currentSelectedRow - halfMemoizationCount && j <= currentSelectedRow + halfMemoizationCount) {
+    int memoizedIndex = j - (currentSelectedRow - halfMemoizationCount);
+    if (m_memoizedCellHeight[memoizedIndex] < 0) {
+      m_memoizedCellHeight[memoizedIndex] = expressionRowHeight(j);
+    }
+    return m_memoizedCellHeight[memoizedIndex];
+  }
+  return expressionRowHeight(j);
+}
+
+KDCoordinate StorageExpressionModelListController::memoizedCumulatedHeightFromIndex(int j) {
+  if (j <= 0) {
+    return 0;
+  }
+  int currentSelectedRow = selectedRow();
+  constexpr int halfMemoizationCount = k_memoizedCellHeightsCount/2;
+  /* If j is not easily computable from the memoized values, compute it the hard
+   * way. */
+  if (j < currentSelectedRow - halfMemoizationCount || j > currentSelectedRow + halfMemoizationCount) {
+    return notMemoizedCumulatedHeightFromIndex(j);
+  }
+  // Recompute the memoized cumulatedHeight if needed
+  if (m_cumulatedHeightForSelectedIndex < 0) {
+    m_cumulatedHeightForSelectedIndex = notMemoizedCumulatedHeightFromIndex(currentSelectedRow);
+  }
+  /* Compute the wanted cumulated height by adding/removing memoized cell
+   * heights */
+  KDCoordinate result = m_cumulatedHeightForSelectedIndex;
+  if (j <= currentSelectedRow) {
+    /* If j is smaller than the selected row, remove cell heights from the
+     * memoized value */
+    for (int i = j; i < currentSelectedRow; i++) {
+      result -= memoizedRowHeight(i);
+    }
+  } else {
+    /* If j is bigger than the selected row, add cell heights to the memoized
+     * value */
+    assert(j > currentSelectedRow && j <= currentSelectedRow + halfMemoizationCount);
+    for (int i = currentSelectedRow; i < j; i++) {
+      result += memoizedRowHeight(i);
+    }
+  }
+  return result;
+}
+
 int StorageExpressionModelListController::numberOfExpressionRows() {
   return 1 + modelStore()->numberOfModels();
 }
@@ -122,4 +215,11 @@ bool StorageExpressionModelListController::isAddEmptyRow(int j) {
   return j == modelStore()->numberOfModels();
 }
 
+void StorageExpressionModelListController::resetMemoization() {
+  m_cumulatedHeightForSelectedIndex = -1;
+  for (int i = 0; i < k_memoizedCellHeightsCount; i++) {
+    m_memoizedCellHeight[i] = -1;
+  }
+}
+
 }

apps/shared/storage_expression_model_list_controller.h

@@ -12,11 +12,15 @@ public:
   StorageExpressionModelListController(Responder * parentResponder, I18n::Message text);
 protected:
   static constexpr KDCoordinate k_expressionMargin = 5;
-  /* Table Data Source */
+  // Memoization of cell heights
+  void tableSelectionDidChange(int previousSelectedRow);
+  KDCoordinate memoizedRowHeight(int j);
+  KDCoordinate memoizedCumulatedHeightFromIndex(int j);
+  // TableViewDataSource
   virtual int numberOfExpressionRows();
   virtual KDCoordinate expressionRowHeight(int j);
   virtual void willDisplayExpressionCellAtIndex(HighlightCell * cell, int j);
-  /* Responder */
+  // Responder
   bool handleEventOnExpression(Ion::Events::Event event);
   virtual void addEmptyModel();
   virtual void didChangeModelsList() {}
@@ -26,11 +30,20 @@ protected:
   virtual bool removeModelRow(Ion::Storage::Record record);
   virtual int modelIndexForRow(int j) { return j; }
   virtual bool isAddEmptyRow(int j);
-  /* View Controller */
+  // ViewController
   virtual SelectableTableView * selectableTableView() = 0;
   virtual StorageExpressionModelStore * modelStore() = 0;
   virtual InputViewController * inputController() = 0;
   EvenOddMessageTextCell m_addNewModel;
+private:
+  // Memoization
+  static constexpr int k_memoizedCellHeightsCount = 5;
+  static_assert(StorageExpressionModelListController::k_memoizedCellHeightsCount == 5, "Wrong array size in initialization of StorageExpressionModelListController::m_memoizedCellHeight.");
+static_assert(StorageExpressionModelListController::k_memoizedCellHeightsCount % 2 == 1, "StorageExpressionModelListController::k_memoizedCellHeightsCount should be odd to be able to compute the middle element.");
+  void resetMemoization();
+  virtual KDCoordinate notMemoizedCumulatedHeightFromIndex(int j) = 0;
+  KDCoordinate m_memoizedCellHeight[k_memoizedCellHeightsCount];
+  KDCoordinate m_cumulatedHeightForSelectedIndex;
 };
 
 }

apps/shared/storage_function_list_controller.cpp

@@ -20,9 +20,7 @@ StorageFunctionListController::StorageFunctionListController(Responder * parentR
       TabViewController * tabController = list->tabController();
       tabController->setActiveTab(2);
     }, this), KDFont::SmallFont, Palette::PurpleBright),
-  m_titlesColumnWidth(k_minTitleColumnWidth),
-  m_memoizedCellHeight {-1, -1, -1, -1, -1},
-  m_cumulatedHeightForSelectedIndex(-1)
+  m_titlesColumnWidth(k_minTitleColumnWidth)
 {
   m_selectableTableView.setMargins(0);
   m_selectableTableView.setVerticalCellOverlap(0);
@@ -36,54 +34,11 @@ void StorageFunctionListController::viewWillAppear() {
 }
 
 KDCoordinate StorageFunctionListController::rowHeight(int j) {
-  if (j < 0) {
-    return 0;
-  }
-  int currentSelectedRow = selectedRow();
-  constexpr int halfMemoizationCount = k_memoizedCellHeightsCount/2;
-  if (j >= currentSelectedRow - halfMemoizationCount && j <= currentSelectedRow + halfMemoizationCount) {
-    int memoizedIndex = j - (currentSelectedRow - halfMemoizationCount);
-    if (m_memoizedCellHeight[memoizedIndex] < 0) {
-      m_memoizedCellHeight[memoizedIndex] = expressionRowHeight(j);
-    }
-    return m_memoizedCellHeight[memoizedIndex];
-  }
-  return expressionRowHeight(j);
+  return StorageExpressionModelListController::memoizedRowHeight(j);
 }
 
 KDCoordinate StorageFunctionListController::cumulatedHeightFromIndex(int j) {
-  if (j <= 0) {
-    return 0;
-  }
-  int currentSelectedRow = selectedRow();
-  constexpr int halfMemoizationCount = k_memoizedCellHeightsCount/2;
-  /* If j is not easily computable from the memoized values, compute it the hard
-   * way. */
-  if (j < currentSelectedRow - halfMemoizationCount || j > currentSelectedRow + halfMemoizationCount) {
-    return TableViewDataSource::cumulatedHeightFromIndex(j);
-  }
-  // Recompute the memoized cumulatedHeight if needed
-  if (m_cumulatedHeightForSelectedIndex < 0) {
-    m_cumulatedHeightForSelectedIndex = TableViewDataSource::cumulatedHeightFromIndex(currentSelectedRow);
-  }
-  /* Compute the wanted cumulated height by adding/removing memoized cell
-   * heights */
-  KDCoordinate result = m_cumulatedHeightForSelectedIndex;
-  if (j <= currentSelectedRow) {
-    /* If j is smaller than the selected row, remove cell heights from the
-     * memoized value */
-    for (int i = j; i < currentSelectedRow; i++) {
-      result -= rowHeight(i);
-    }
-  } else {
-    /* If j is bigger than the selected row, add cell heights to the memoized
-     * value */
-    assert(j > currentSelectedRow && j <= currentSelectedRow + halfMemoizationCount);
-    for (int i = currentSelectedRow; i < j; i++) {
-      result += rowHeight(i);
-    }
-  }
-  return result;
+  return StorageExpressionModelListController::memoizedCumulatedHeightFromIndex(j);
 }
 
 KDCoordinate StorageFunctionListController::columnWidth(int i) {
@@ -260,44 +215,9 @@ void StorageFunctionListController::willExitResponderChain(Responder * nextFirst
 /* SelectableTableViewDelegate */
 
 void StorageFunctionListController::tableViewDidChangeSelection(SelectableTableView * t, int previousSelectedCellX, int previousSelectedCellY) {
-  constexpr int currentSelectedMemoizedIndex = k_memoizedCellHeightsCount/2 + 1; // Needs k_memoizedCellHeightsCount to be odd, which is static asserted in storage_function_list_controller.h
-  int currentSelectedY = selectedRow();
-
-  // The previously selected cell's height might have changed.
-  m_memoizedCellHeight[currentSelectedMemoizedIndex] = -1;
-
-  // Update m_cumulatedHeightForSelectedIndex if we scrolled one cell up/down
-  if (currentSelectedY == previousSelectedCellY + 1) {
-    /* We selected the cell under the previous cell. Shift the memoized cell
-     * heights. */
-    for (int i = 0; i < k_memoizedCellHeightsCount - 1; i++) {
-      m_memoizedCellHeight[i] = m_memoizedCellHeight[i+1];
-    }
-    m_memoizedCellHeight[k_memoizedCellHeightsCount-1] = -1;
-    // Update m_cumulatedHeightForSelectedIndex
-    if (previousSelectedCellY >= 0) {
-      m_cumulatedHeightForSelectedIndex+= rowHeight(previousSelectedCellY);
-    } else {
-      assert(currentSelectedY == 0);
-      m_cumulatedHeightForSelectedIndex = 0;
-    }
-  } else if (currentSelectedY == previousSelectedCellY - 1) {
-    /* We selected the cell above the previous cell. Shift the memoized cell
-     * heights. */
-    for (int i = k_memoizedCellHeightsCount - 1; i > 0; i--) {
-      m_memoizedCellHeight[i] = m_memoizedCellHeight[i-1];
-    }
-    m_memoizedCellHeight[0] = -1;
-    // Update m_cumulatedHeightForSelectedIndex
-    if (currentSelectedY >= 0) {
-      m_cumulatedHeightForSelectedIndex-= rowHeight(currentSelectedY);
-    } else {
-      m_cumulatedHeightForSelectedIndex = 0;
-    }
-  } else if (previousSelectedCellY != currentSelectedY) {
-    resetMemoization();
-  }
-
+  // Update memoization of cell heights
+  StorageExpressionModelListController::tableSelectionDidChange(previousSelectedCellY);
+  // Do not select the cell left of the "addEmptyFunction" cell
   if (isAddEmptyRow(selectedRow()) && selectedColumn() == 0) {
     t->selectCellAtLocation(1, numberOfRows()-1);
   }
@@ -351,11 +271,8 @@ void StorageFunctionListController::didChangeModelsList() {
   computeTitlesColumnWidth();
 }
 
-void StorageFunctionListController::resetMemoization() {
-  m_cumulatedHeightForSelectedIndex = -1;
-  for (int i = 0; i < k_memoizedCellHeightsCount; i++) {
-    m_memoizedCellHeight[i] = -1;
-  }
+KDCoordinate StorageFunctionListController::notMemoizedCumulatedHeightFromIndex(int j) {
+  return TableViewDataSource::cumulatedHeightFromIndex(j);
 }
 
 }

apps/shared/storage_function_list_controller.h

@@ -58,25 +58,20 @@ protected:
 private:
   static constexpr KDCoordinate k_minTitleColumnWidth = 65;
   static constexpr KDCoordinate k_functionTitleSumOfMargins = 2*Metric::HistoryHorizontalMargin;
-  static constexpr int k_memoizedCellHeightsCount = 5;
-  static_assert(StorageFunctionListController::k_memoizedCellHeightsCount == 5, "Wrong array size in initialization of StorageFunctionListController::m_memoizedCellHeight.");
-static_assert(StorageFunctionListController::k_memoizedCellHeightsCount % 2 == 1, "StorageFunctionListController::k_memoizedCellHeightsCount should be odd to be able to compute the middle element.");
   TabViewController * tabController() const;
   InputViewController * inputController() override;
   KDCoordinate maxFunctionNameWidth();
   void didChangeModelsList() override;
+  KDCoordinate notMemoizedCumulatedHeightFromIndex(int j) override;
   virtual StorageListParameterController * parameterController() = 0;
   virtual int maxNumberOfDisplayableRows() = 0;
   virtual FunctionTitleCell * titleCells(int index) = 0;
   virtual HighlightCell * expressionCells(int index) = 0;
   virtual void willDisplayTitleCellAtIndex(HighlightCell * cell, int j) = 0;
-  void resetMemoization();
   EvenOddCell m_emptyCell;
   Button m_plotButton;
   Button m_valuesButton;
   KDCoordinate m_titlesColumnWidth;
-  KDCoordinate m_memoizedCellHeight[k_memoizedCellHeightsCount];
-  KDCoordinate m_cumulatedHeightForSelectedIndex;
 };
 
 }