I've got a design issue... it's more of a block than anything. I have created several classes that allow me to do draw things to the screen in a nice simple way. I've also made these classes compatible with the Observer pattern, but I can't think of a way to use these in unison. I'd like to learn how to translate a button being clicked to increasing volume... or exiting the program... etc. But I want it to be handled neatly, not in some giant switch case in main...
class Screen : public Drawable, public Updateable, public Uncopyable, public Observer
{
public:
Screen();
Screen(const std::string& directory);
virtual ~Screen();
virtual void Draw(SDL_Surface* screen);
virtual void Update(const SDL_Event& event_);
virtual void Notify(Observable* observable, void* oe);
protected:
virtual void Load(const std::string& directory);
virtual void Load_Elements(const std::string& directory);
virtual void Load_Observation(const std::string& directory);
std::vector<Base_XImage*> elements;
};
class Base_XImage : public Drawable, public Updateable, public Cloneable, public Observable
{
public:
typedef enum OBSERVABLE_EVENT
{
LMB_CLICK,
RMB_CLICK,
MOUSE_OVER
};
Base_XImage();
Base_XImage(
const std::string& name_,
const std::string& file_name_,
int position_x,
int position_y,
bool is_colour_key_,
SDL_Colour colour_key_ = SDL_Wrappers::colour(0,0,0));
Base_XImage(const Base_XImage& rhs);
virtual ~Base_XImage();
Base_XImage& operator=(const Base_XImage& rhs);
const std::string& Get_Name() const;
const std::string& Get_File_Name() const;
const SDL_Rect& Get_Position() const;
bool Is_Colour_Key() const;
const SDL_Colour& Get_Colour_Key() const;
virtual void Load();
virtual void Draw(SDL_Surface* screen) = 0;
virtual void Update(const SDL_Event& event_) = 0;
virtual Base_XImage* Clone() const = 0;
protected:
static void Check_Opening_Tag(const std::string& buffer);
static void Check_Closing_Tag(const std::string& buffer);
std::string name;
std::string file_name;
SDL_Rect position;
bool is_colour_key;
SDL_Colour colour_key;
SDL_Surface* surface;
};
As you can see, I've only started to implement the Observer pattern. I don't know how I'm going to actually use it. This is a sample loop of a program using the Screen class:
Draw_Engine DE;
DE.Initialise(640, 480, 24, "SDL Testing", "C:/WINDOWS/Fonts/Arial.ttf");
Audio_Engine AE;
AE.Initialise();
Screen test_screen("Screens/Screen_Test_Screen/");
SDL_Event event_;
bool exit = false;
while(!exit)
{
while(SDL_PollEvent(&event_))
{
if(event_.type == SDL_QUIT)
{
exit = true;
break;
}
// Update screen elements.
test_screen.Update(event_);
// Draw(blit) elements to screen.
test_screen.Draw(DE.Get_Screen());
// Draw screen.
DE.Draw_Screen();
}
}
DE.Clean_Up();
AE.Clean_Up();
The string parameter passed to the Screen constructor is the directory where all the info for the elements are. For each class (Image, Button, Audible_Button, Draggable_Button, etc.) I create a new .txt file with all the elements of that type that I want to be drawn to the screen:
Quote:< test1 1.png 10 10 0 >
Should I just use something like wxWidgets instead of doing this all on my own? I guess you could say that I'm looking to create a GUI framework.. or use an existing one so I can get on with finishing my game. :)
