Program Model – Error List Changes

The program model is now keeping a list of errors in the program.  This list will be used to create the extra selections in the edit box to highlight the errors in the program.  A signal was added to the program model to emit the error list when it changes and a slot was added to the edit box to receive the error list.  For now, this slot just outputs the error list with indicators of the start and end errors that were changed.

The error list class was modified to capture the start and end indexes of the changes to a list when the program model receives a lines changed signal.  New start and end change indexes were added to the error list class along with access functions - one for resetting these indexes called at the start of the program model update slot, one for checking if there was a change to the error list called at the end of the update slot (to determine if the error list change signal should be emitted), and two to access each index called by the edit box to update the error highlighting.

To catch when errors in the list are modified, the insert, remove and replace functions in the error list class were overloaded.  Each calls the QList base function and then calls a new set change index private function, which checks if the index being modified is lower or higher then the current start and end change indexes.  New increment and decrement line number functions were also implemented, which call the error item functions and then the set change index function.

The new update errors slot function for the edit box class receives the error list change signal.  For now, the function just outputs the error list with indicators on the errors that changed, which was used for debugging.

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