Added screen error messages

src/app/ScreenManager.cpp

@@ -1,6 +1,10 @@
 #include "ScreenManager.h"
 
-ScreenManager::ScreenManager(Adafruit_SSD1306 &display) : _displayRef(display), _displayColorInverted(false), _displayDimmed(false), _currentView(NULL), _error(0)
+ScreenManager::ScreenManager(Adafruit_SSD1306 &display) : _displayRef(display), _displayColorInverted(false), _displayDimmed(false), _currentView(NO_CURRENT_VIEW), _error(0)
+, _viewNotFound{&(displayError), (ErrorInfo *)malloc(sizeof(ErrorInfo)), RESERVED_VIEW_UID, NULL}
+, _viewFuncUndefined{&(displayError), (ErrorInfo *)malloc(sizeof(ErrorInfo)), RESERVED_VIEW_UID, NULL}
+, _currentViewUndefined{&(displayError), (ErrorInfo *)malloc(sizeof(ErrorInfo)), RESERVED_VIEW_UID, NULL}
+, _viewFunctionFailedToExecute{&(displayError), (ErrorInfo *)malloc(sizeof(ErrorInfo)), RESERVED_VIEW_UID, NULL}
 {  
   _viewLinkedList = (ViewLinkedList) createEmptyList();
   _displayRef.setRotation(OR_0);
@@ -131,45 +135,85 @@ ViewLink* ScreenManager::getLinkByUID(ViewLinkedList viewLinkedList, const unsig
 
 boolean ScreenManager::displayView(const int UID)
 {
-  boolean result = false;
+  //Reset draw settings:
+  _displayRef.clearDisplay();
+  _displayRef.setCursor(0,0);
+  _displayRef.setTextSize(1);
+  
   
   if(UID == -1 && _currentView == NO_CURRENT_VIEW)
   {
     //We display an error message on the screen
-    
+    ((ErrorInfo *)_currentViewUndefined.pData)->errorMessage = F("Could not display current view");
+    ((ErrorInfo *)_currentViewUndefined.pData)->viewUID = UID;
+    (*_currentViewUndefined.viewLogicFunction)(_displayRef, _currentViewUndefined.pData);
+    _displayRef.display();
     return false;
   }
   else if(UID == -1)
   {
+    if(!(*_currentView->viewLogicFunction)(_displayRef, _currentView->pData))
+    {
+      //We display an error message on the screen
       _displayRef.clearDisplay();
-    _displayRef.setCursor(0,0);
+      ((ErrorInfo *)_viewFunctionFailedToExecute.pData)->errorMessage = F("View function failed\nto execute");
-    result = (*_currentView->viewLogicFunction)(_displayRef, _currentView->pData);
+      ((ErrorInfo *)_viewFunctionFailedToExecute.pData)->viewUID = UID;
+      (*_viewFunctionFailedToExecute.viewLogicFunction)(_displayRef, _viewFunctionFailedToExecute.pData);
       _displayRef.display();
       
-    return result;
+      _currentView = &_viewFunctionFailedToExecute;
+      return false;
+    }
+    
+    _displayRef.display();
+    return true;
   }
     
   ViewLink *viewLink = getLinkByUID(_viewLinkedList, UID);
   if(viewLink == NULL)
   {
     //We display an error message on the screen
+    ((ErrorInfo *)_viewNotFound.pData)->errorMessage = F("View does not exist");
+    ((ErrorInfo *)_viewNotFound.pData)->viewUID = UID;
+    (*_viewNotFound.viewLogicFunction)(_displayRef, _viewNotFound.pData);
+    _displayRef.display();
 
+    _currentView = &_viewNotFound;
     return false;
   }else if(viewLink->viewLogicFunction == NULL)
   {
     //We display an error message on the screen
+    ((ErrorInfo *)_viewFuncUndefined.pData)->errorMessage = F("View function is NULL");
+    ((ErrorInfo *)_viewFuncUndefined.pData)->viewUID = UID;
+    (*_viewFuncUndefined.viewLogicFunction)(_displayRef, _viewFuncUndefined.pData);
+    _displayRef.display();
     
+    _currentView = &_viewFuncUndefined;
     return false;
   }
   
-  _currentView = viewLink;
   
+  if(!(*viewLink->viewLogicFunction)(_displayRef, viewLink->pData))
+  {
+    //We display an error message on the screen
       _displayRef.clearDisplay();
-  _displayRef.setCursor(0,0);
+      ((ErrorInfo *)_viewFunctionFailedToExecute.pData)->errorMessage = F("View function failed\nto execute");
-  result = (*viewLink->viewLogicFunction)(_displayRef, viewLink->pData);
+      ((ErrorInfo *)_viewFunctionFailedToExecute.pData)->viewUID = UID;
+      (*_viewFunctionFailedToExecute.viewLogicFunction)(_displayRef, _viewFunctionFailedToExecute.pData);
       _displayRef.display();
       
-  return result;
+      _currentView = &_viewFunctionFailedToExecute;
+      return false;
+  }
+  
+  _displayRef.display();
+  _currentView = viewLink;
+  return true;
+}
+
+boolean ScreenManager::displayNextView()
+{
+  return true;
 }
 
 void ScreenManager::invertDisplayColor(const boolean inverted)
@@ -215,4 +259,46 @@ void ScreenManager::clearDisplay(const boolean bufferOnly)
   }
 }
 
+unsigned char ScreenManager::getViewCount()
+{
+  unsigned char counter = 0;
+  ViewLinkedList temp = _viewLinkedList;
+  while(!isListEmpty(temp))
+  {
+    counter++;
+    temp = temp->next;
+  }
+  return counter;
+}
+
+int ScreenManager::getCurrentViewUID() const
+{
+  if(_currentView == NO_CURRENT_VIEW)
+    return -1;
+  return _currentView->UID < 0 ? -1 : _currentView->UID;
+}
+
+boolean ScreenManager::displayError(Adafruit_SSD1306 &display, void *pData)
+{
+  const ErrorInfo *errorInfo = (ErrorInfo *) pData;
+  
+  display.setTextSize(3);  
+  display.setCursor(19,3);
+  display.drawRect(0,0,display.width(), 27, WHITE);
+  display.print(F("ERROR"));
+  display.setTextSize(1);
+  display.setCursor(0,29);
+  display.print(errorInfo->errorMessage);
+  //We then display the view UID that caused the probleme
+  
+  if(errorInfo->viewUID >= 0)
+  {
+    display.setCursor(0,56);
+    char buff[30] = "";
+    sprintf(buff,"VIEW UID : %d" ,errorInfo->viewUID);  
+    display.println(buff);
+  }
+  
+  return true;
+}
 

src/app/ScreenManager.h

@@ -10,6 +10,7 @@ class ScreenManager
     boolean addView(boolean (*viewLogicFunction)(Adafruit_SSD1306&, void*), void *pData, const unsigned char UID);
     boolean removeView(const unsigned char UID);
     boolean displayView(const int UID = -1);
+    boolean displayNextView();
     void invertDisplayColor(const boolean inverted);
     void orientDisplay(const Orientation orientation);
     void dimDisplay(const boolean dimmed);
@@ -19,7 +20,8 @@ class ScreenManager
     boolean isDisplayColorInverted() const;
     Orientation getDisplayOrientation() const;
     boolean isDisplayDimmed() const;
-    ViewLink* getCurrentView() const;
+    int getCurrentViewUID() const;
+    unsigned char getViewCount();
 
     
     void iterateThroughList();
@@ -32,6 +34,7 @@ class ScreenManager
     boolean removeLinkByUID(ViewLinkedList *viewLinkedList, const unsigned char UID);
     ViewLink* getLinkByUID(ViewLinkedList viewLinkedList, const unsigned char UID);
     boolean isListEmpty(ViewLinkedList viewLinkedList);
+    static boolean displayError(Adafruit_SSD1306 &display, void *pData);
     
     Adafruit_SSD1306 &_displayRef;
     ViewLinkedList _viewLinkedList;
@@ -39,6 +42,10 @@ class ScreenManager
     boolean _displayColorInverted;
     boolean _displayDimmed;
     ViewLink* _currentView;
+    ViewLink _viewNotFound, _viewFuncUndefined, _currentViewUndefined, _viewFunctionFailedToExecute;
+
+    //This structure contains the error message as well as the UID from the view that caused the error if available.
+    typedef struct {const __FlashStringHelper* errorMessage; int viewUID;} ErrorInfo;
 };
 
 #endif //SCREENMANAGER_H