#ifndef VALUEDGUIELEMENT_H
#define VALUEDGUIELEMENT_H

#include <allegro.h>

#include "GuiElement.h"
#include "constant.h"

extern int installMouseReturnValue;

extern int layerCount;

extern bool forgotScreen;

extern volatile bool heartBeat;

extern void unload();

extern void drawSpritesForBlitting();

extern void showFrame();
extern void createGraphicsBackup(int layersWanted);
extern void restoreGraphicsBackup(int layersWanted);

extern void drawFrame();

extern void setHeartBeat();

template<class T> class ValuedGuiElement : public GuiElement {
       bool committed;
       T commitment;
       
       protected:
       bool blocking;
       
       ValuedGuiElement(BITMAP *desiredCanvas, bool desiredBlocking,
         bool desiredActive = false) : GuiElement(desiredCanvas, desiredActive),
         blocking(desiredBlocking), committed(false) {}
       
       public:
       bool getCommitted() const {
            return committed;
       }
       T getCommitment() const {
         return commitment;
       }
       virtual T getValue() = 0;
       
       void commit(T desiredCommitment) {
            if (!committed) {
               committed = true;
               commitment = desiredCommitment;
            }
       }
       void uncommit() {
            committed = false;
       }
       
       T block(bool blinking) {
          if (!getCommitted()) {
             erase();
             createGraphicsBackup(layerCount);
             
             heartBeat = false;
             if (blinking)
                remove_int(setHeartBeat);
             install_int(setHeartBeat, cursorBlinkDelay);
             focus();
             clear_keybuf();
             while (!getCommitted()) {
                   erase();
                   draw();
                   drawFrame();
                   showFrame();
                   
                   bool somethingHappened = false;
                   do {
                         if (forgotScreen) {
                            drawSpritesForBlitting();
                            restoreGraphicsBackup(layerCount);
                            
                            draw();
                            drawFrame();
                            showFrame();
                            
                            forgotScreen = false;
                         }
                         rest(0);
                         if (keyboard_needs_poll())
                            if (poll_keyboard()) {
                               unload();
                               allegro_message("Couldn't poll the keyboard!");
                               exit(0);
                            }
                         if (mouse_needs_poll())
                            if (poll_mouse()) {
                               unload();
                               allegro_message("Couldn't poll the mouse!");
                               exit(0);
                            }
                         if (keypressed() && acknowledgeKeyStroke(readkey()))
                            somethingHappened = true;
                         if (acknowledgeKeyArray())
                            somethingHappened = true;
                         if (installMouseReturnValue != -1 &&
                             acknowledgeMouse())
                            somethingHappened = true;
                   } while (!(somethingHappened || heartBeat));
                   
                   if (somethingHappened) {
                      heartBeat = false;
                      remove_int(setHeartBeat);
                      install_int(setHeartBeat, cursorBlinkDelay);
                   }
                   if (heartBeat) {
                      acknowledgeHeartBeat();
                      heartBeat = false;
                   }
             }
             remove_int(setHeartBeat);
             if (blinking)
                install_int(setHeartBeat, cursorBlinkDelay);
          }
          return getCommitment();
       }
};

#endif