void DeleteLine::undo(EditorModel& model){ // Handling deletion of line if cursor is not in the first line if(lineNumber != firstLine){ model.insertString(lineNumber, oldString); model.incrementLineCount(); // If previous line was at the end of the text if(lineNumber == model.lineCount()){ model.incrementCursorLine(); } } // Handling deletion of first line of text else{ // If first line contained either empty string or was not the last line of text if (oldString == emptyString || lineCount != 1){ model.incrementLineCount(); model.insertString(lineNumber, oldString); } // Initializes first line of text if it was the only line left else{ model.setLineString(lineNumber, oldString); } } // Fix cursor positioning model.setCursorColumn(cursorPos); }
void DeleteLine::execute(EditorModel& model){ // Obtain previous values of pre-deletion for line oldString = model.line(model.cursorLine()); lineNumber = model.cursorLine(); cursorPos = model.cursorColumn(); lineCount = model.lineCount(); // Throw error if text is empty if (lineNumber == firstLine && model.line(lineNumber) == emptyString && model.lineCount() == 1){ model.setErrorMessage( deleteLineError.getReason() ); throw deleteLineError; } // Empty the first line if that is the only line in the text (there should be at least one line in the text) if (model.lineCount() == firstLine){ model.setLineString(firstLine, emptyString); model.setCursorColumn(1); } // Delete the line and move the curser up if you are at the end of the page else{ // Set boolean variables for cursor line placement const bool atBeginningOfPage = model.cursorAtBeginningOfPage(); const bool atEndOfPage = model.cursorAtEndOfPage(); const bool previousColumnPlacementTooFar = model.cursorColumn() > model.line(model.cursorLine()).length(); // Only initialize this boolean if you are not at the end of the page const bool nextColumnPlacementTooFar = !atEndOfPage ? model.cursorColumn() > model.line(model.cursorLine()+1).length() : false; // Deletes current line from text model.deleteLine(model.cursorLine()); // Move cursor up if at the end of the page if (atEndOfPage){ CursorUp c; c.execute(model); } // Fix cursor column placement if cursor is at the beginning of text, else if (atBeginningOfPage && previousColumnPlacementTooFar){ model.setCursorColumn(model.line(model.cursorLine()).length()+1); } else if (nextColumnPlacementTooFar){ model.setCursorColumn(model.line(model.cursorLine()).length()+1); } // Decrement the current line count model.decrementLineCount(); } }