[escher] New handling of stack view headers in StackViewController.

A boolean in ViewController states if the ViewController wants MaximumSpace (do
not show any stack view headers), or if it does not want to add its own title to
the stack view headers. If the ViewController's title is null, it is not added
to the stack view headers.
By default, ButtonRowControllers do not want to add their title (because they
are only used for now in TabViews, where the title is already displayed in the
tab).

Change-Id: I9e4c64b845262e4d44eb03cf769950f9c9e67a3a

apps/sequence/list/list_controller.cpp

@@ -14,7 +14,7 @@ ListController::ListController(Responder * parentResponder, SequenceStore * sequ
   m_expressionCells{},
   m_parameterController(this, sequenceStore),
   m_typeParameterController(this, sequenceStore, this, TableCell::Layout::Vertical),
-  m_typeStackController(nullptr, &m_typeParameterController, true, KDColorWhite, Palette::PurpleDark, Palette::PurpleDark),
+  m_typeStackController(nullptr, &m_typeParameterController, KDColorWhite, Palette::PurpleDark, Palette::PurpleDark),
   m_sequenceToolbox()
 {
 }

apps/settings/main_controller.cpp

@@ -58,9 +58,6 @@ MainController::~MainController() {
     m_complexFormatLayout = nullptr;
   }
 }
-const char * MainController::title() {
-  return I18n::translate(m_messageTreeModel->label());
-}
 
 View * MainController::view() {
   return &m_selectableTableView;

apps/settings/main_controller.h

@@ -17,7 +17,6 @@ public:
   MainController& operator=(const MainController& other) = delete;
   MainController& operator=(MainController&& other) = delete;
   View * view() override;
-  const char * title() override;
   bool handleEvent(Ion::Events::Event event) override;
   void didBecomeFirstResponder() override;
   int numberOfRows() override;

apps/variable_box_controller.cpp

@@ -278,7 +278,7 @@ void VariableBoxController::ContentViewController::viewDidDisappear() {
 }
 
 VariableBoxController::VariableBoxController(GlobalContext * context) :
-  StackViewController(nullptr, &m_contentViewController, true, KDColorWhite, Palette::PurpleBright, Palette::PurpleDark),
+  StackViewController(nullptr, &m_contentViewController, KDColorWhite, Palette::PurpleBright, Palette::PurpleDark),
   m_contentViewController(this, context)
 {
 }

escher/include/escher/button_row_controller.h

@@ -28,6 +28,7 @@ public:
   bool setSelectedButton(int selectedButton);
   void viewWillAppear() override;
   void viewDidDisappear() override;
+  ViewController::DisplayParameter displayParameter() override { return DisplayParameter::DoNotShowOwnTitle; }
 private:
   class ContentView : public View {
   public:

escher/include/escher/stack_view_controller.h

@@ -9,7 +9,7 @@ constexpr uint8_t kMaxNumberOfStacks = 4;
 
 class StackViewController : public ViewController {
 public:
-  StackViewController(Responder * parentResponder, ViewController * rootViewController, bool displayFirstStackHeader = false,
+  StackViewController(Responder * parentResponder, ViewController * rootViewController,
     KDColor textColor = Palette::SubTab, KDColor backgroundColor = KDColorWhite, KDColor separatorColor = Palette::GreyBright);
 
   /* Push creates a new StackView and adds it */
@@ -43,7 +43,9 @@ private:
   };
   class ControllerView : public View {
   public:
-    ControllerView(bool displayFirstStackHeader);
+    ControllerView();
+    void shouldDisplayStackHearders(bool shouldDisplay);
+    int8_t numberOfStacks() const { return m_numberOfStacks; }
     void setContentView(View * view);
     void pushStack(Frame frame);
     void popStack();
@@ -60,7 +62,7 @@ private:
     StackView m_stackViews[kMaxNumberOfStacks];
     View * m_contentView;
     int8_t m_numberOfStacks;
-    bool m_displayFirstStackHeader;
+    bool m_displayStackHeaders;
   };
   ControllerView m_view;
   void pushModel(Frame frame);

escher/include/escher/view_controller.h

@@ -29,11 +29,23 @@ extern "C" {
 
 class ViewController : public Responder {
 public:
+  /* DisplayParameter is only used within StackViewController for now. It
+   * modifies the stack headers display. */
+  enum class DisplayParameter {
+    Default,
+    DoNotShowOwnTitle,
+    /* With DoNotShowOwnTitle, the title of the ViewController is not added to
+     * the stack headers. */
+    WantsMaximumSpace
+    /* With WantsMaximumSpace, no stack headers are displayed. */
+  };
+
   ViewController(Responder * parentResponder);
   virtual const char * title();
   virtual View * view() = 0;
   virtual void viewWillAppear();
   virtual void viewDidDisappear();
+  virtual DisplayParameter displayParameter() { return DisplayParameter::Default; }
 };
 
 #endif

escher/src/stack_view_controller.cpp

@@ -4,14 +4,18 @@ extern "C" {
 #include <escher/stack_view_controller.h>
 #include <escher/app.h>
 
-StackViewController::ControllerView::ControllerView(bool displayFirstStackHeader) :
+StackViewController::ControllerView::ControllerView() :
   View(),
   m_contentView(nullptr),
   m_numberOfStacks(0),
-  m_displayFirstStackHeader(displayFirstStackHeader)
+  m_displayStackHeaders(true)
 {
 }
 
+void StackViewController::ControllerView::shouldDisplayStackHearders(bool shouldDisplay) {
+  m_displayStackHeaders = shouldDisplay;
+}
+
 void StackViewController::ControllerView::setContentView(View * view) {
   m_contentView = view;
   layoutSubviews();
@@ -33,23 +37,30 @@ void StackViewController::ControllerView::popStack() {
 
 void StackViewController::ControllerView::layoutSubviews() {
   KDCoordinate width = m_frame.width();
-  int indexFirstHeader = m_displayFirstStackHeader ? 0 : 1;
-  for (int i=indexFirstHeader; i<m_numberOfStacks; i++) {
-    m_stackViews[i].setFrame(KDRect(0, k_stackHeight*(i-indexFirstHeader), width, k_stackHeight + 1));
+  if (m_displayStackHeaders) {
+    for (int i=0; i<m_numberOfStacks; i++) {
+      m_stackViews[i].setFrame(KDRect(0, k_stackHeight*i, width, k_stackHeight + 1));
+    }
   }
   if (m_contentView) {
-    bool separatorHeight = m_displayFirstStackHeader + (m_numberOfStacks > 1);
-    KDRect contentViewFrame = KDRect( 0, (m_numberOfStacks-indexFirstHeader)*k_stackHeight + separatorHeight,
-        width, m_frame.height() - (m_numberOfStacks-indexFirstHeader)*k_stackHeight);
+    bool separatorHeight = m_numberOfStacks > 1;
+    KDRect contentViewFrame = KDRect( 0,
+        m_displayStackHeaders * (m_numberOfStacks * k_stackHeight + separatorHeight),
+        width,
+        m_frame.height() - m_displayStackHeaders * m_numberOfStacks * k_stackHeight);
     m_contentView->setFrame(contentViewFrame);
   }
 }
 
 int StackViewController::ControllerView::numberOfSubviews() const {
-  return m_numberOfStacks + (m_contentView == nullptr ? 0 : 1);
+  return (m_displayStackHeaders ? m_numberOfStacks : 0) + (m_contentView == nullptr ? 0 : 1);
 }
 
 View * StackViewController::ControllerView::subviewAtIndex(int index) {
+  if (!m_displayStackHeaders) {
+    assert(index == 0);
+    return m_contentView;
+  }
   if (index < m_numberOfStacks) {
     assert(index >= 0);
     return &m_stackViews[index];
@@ -65,10 +76,9 @@ const char * StackViewController::ControllerView::className() const {
 }
 #endif
 
-StackViewController::StackViewController(Responder * parentResponder, ViewController * rootViewController,
-    bool displayFirstStackHeader, KDColor textColor, KDColor backgroundColor, KDColor separatorColor) :
+StackViewController::StackViewController(Responder * parentResponder, ViewController * rootViewController, KDColor textColor, KDColor backgroundColor, KDColor separatorColor) :
   ViewController(parentResponder),
-  m_view(displayFirstStackHeader),
+  m_view(),
   m_numberOfChildren(0),
   m_isVisible(false)
 {
@@ -88,8 +98,10 @@ void StackViewController::push(ViewController * vc, KDColor textColor, KDColor b
   if (!m_isVisible) {
     return;
   }
-  /* Load stack view */
-  m_view.pushStack(frame);
+  /* Load stack view if the View Controller has a title. */
+  if (vc->title() != nullptr && vc->displayParameter() != ViewController::DisplayParameter::DoNotShowOwnTitle) {
+    m_view.pushStack(frame);
+  }
   setupActiveViewController();
   if (m_numberOfChildren > 1) {
     m_childrenFrame[m_numberOfChildren-2].viewController()->viewDidDisappear();
@@ -97,9 +109,11 @@ void StackViewController::push(ViewController * vc, KDColor textColor, KDColor b
 }
 
 void StackViewController::pop() {
-  m_view.popStack();
   assert(m_numberOfChildren > 0);
   ViewController * vc = m_childrenFrame[m_numberOfChildren-1].viewController();
+  if (vc->title() != nullptr && vc->displayParameter() != ViewController::DisplayParameter::DoNotShowOwnTitle) {
+    m_view.popStack();
+  }
   m_numberOfChildren--;
   setupActiveViewController();
   vc->setParentResponder(nullptr);
@@ -117,6 +131,7 @@ void StackViewController::pushModel(Frame frame) {
 void StackViewController::setupActiveViewController() {
   ViewController * vc = m_childrenFrame[m_numberOfChildren-1].viewController();
   vc->setParentResponder(this);
+  m_view.shouldDisplayStackHearders(vc->displayParameter() != ViewController::DisplayParameter::WantsMaximumSpace);
   m_view.setContentView(vc->view());
   vc->viewWillAppear();
   vc->setParentResponder(this);
@@ -143,12 +158,16 @@ View * StackViewController::view() {
 void StackViewController::viewWillAppear() {
   /* Load the stack view */
   for (int i = 0; i < m_numberOfChildren; i++) {
-    m_view.pushStack(m_childrenFrame[i]);
+    ViewController * childrenVC = m_childrenFrame[i].viewController();
+    if (childrenVC->title() != nullptr && childrenVC->displayParameter() != ViewController::DisplayParameter::DoNotShowOwnTitle) {
+      m_view.pushStack(m_childrenFrame[i]);
+    }
   }
   /* Load the visible controller view */
   ViewController * vc = m_childrenFrame[m_numberOfChildren-1].viewController();
   if (m_numberOfChildren > 0 && vc) {
     m_view.setContentView(vc->view());
+    m_view.shouldDisplayStackHearders(vc->displayParameter() != ViewController::DisplayParameter::WantsMaximumSpace);
     vc->viewWillAppear();
   }
   m_isVisible = true;
@@ -159,7 +178,7 @@ void StackViewController::viewDidDisappear() {
   if (m_numberOfChildren > 0 && vc) {
     vc->viewDidDisappear();
   }
-  for (int i = 0; i < m_numberOfChildren; i++) {
+  for (int i = 0; i < m_view.numberOfStacks(); i++) {
     m_view.popStack();
   }
   m_isVisible = false;

escher/src/toolbox.cpp

@@ -85,7 +85,7 @@ void Toolbox::ListController::setFirstSelectedRow(int firstSelectedRow) {
 /* Toolbox */
 
 Toolbox::Toolbox(Responder * parentResponder, const char * title) :
-  StackViewController(parentResponder, &m_listController, true, KDColorWhite, Palette::PurpleBright, Palette::PurpleDark),
+  StackViewController(parentResponder, &m_listController, KDColorWhite, Palette::PurpleBright, Palette::PurpleDark),
   m_selectableTableView(&m_listController, this, 0, 1, 0, 0, 0, 0, this, nullptr, false),
   m_listController(this, &m_selectableTableView, title),
   m_messageTreeModel(nullptr),