Use Polymorphisim for getting the text value of a control

gemrb/core/GUI/Control.h

@@ -151,6 +151,7 @@ class GEM_EXPORT Control {
 	virtual bool IsPixelTransparent(unsigned short /*x*/, unsigned short /*y*/) {
 		return false;
 	}
+	virtual const char* QueryText() const { return NULL; }
 	/** Sets the animation picture ref */
 	void SetAnimPicture(Sprite2D* Picture);
 	/** Sets the Scroll Bar Pointer */

gemrb/core/GUI/TextArea.cpp

@@ -897,12 +897,12 @@ void TextArea::SelectText(const char *select)
 	}
 }
 
-const char* TextArea::QueryText()
+const char* TextArea::QueryText() const
 {
 	if ( Value<lines.size() ) {
 		return ( const char * ) lines[Value];
 	}
-	return ( const char *) "";
+	return "";
 }
 
 bool TextArea::SetEvent(int eventType, EventHandler handler)

gemrb/core/GUI/TextArea.h

@@ -118,7 +118,7 @@ class GEM_EXPORT TextArea : public Control {
 	/** Copies the current TextArea content to another TextArea control */
 	void CopyTo(TextArea* ta);
 	/** Returns the selected text */
-	const char* QueryText();
+	const char* QueryText() const;
 	/** Marks textarea for redraw with a new value */
 	void UpdateState(const char* VariableName, unsigned int Sum);
 	int SetScrollBar(Control *ptr);

gemrb/core/GUI/TextEdit.cpp

@@ -224,7 +224,7 @@ void TextEdit::SetBufferLength(ieWord buflen)
 }
 
 /** Simply returns the pointer to the text, don't modify it! */
-const char* TextEdit::QueryText()
+const char* TextEdit::QueryText() const
 {
 	return ( const char * ) Buffer;
 }

gemrb/core/GUI/TextEdit.h

@@ -66,8 +66,8 @@ class GEM_EXPORT TextEdit : public Control {
 	void SetBackGround(Sprite2D* back);
 	/** Sets the Text of the current control */
 	void SetText(const char* string);
-	/** Sets the Text of the current control */
-	const char* QueryText();
+	/** Gets the Text of the current control */
+	const char* QueryText() const;
 	/** Sets the buffer length */
 	void SetBufferLength(ieWord buflen);
 	/** Sets the alignment */

gemrb/plugins/GUIScript/GUIScript.cpp

@@ -1359,16 +1359,7 @@ static PyObject* GemRB_Control_QueryText(PyObject * /*self*/, PyObject* args)
 	if (!ctrl) {
 		return NULL;
 	}
-	switch(ctrl->ControlType) {
-	case IE_GUI_LABEL:
-		return PyString_FromString(((Label *) ctrl)->QueryText() );
-	case IE_GUI_EDIT:
-		return PyString_FromString(((TextEdit *) ctrl)->QueryText() );
-	case IE_GUI_TEXTAREA:
-		return PyString_FromString(((TextArea *) ctrl)->QueryText() );
-	default:
-		return RuntimeError("Invalid control type");
-	}
+	return PyString_FromString(ctrl->QueryText() ?: "");
 }
 
 PyDoc_STRVAR( GemRB_TextEdit_SetBufferLength__doc,