KeyManager.h

00001 /**
00002  * Class KeyManager
00003  *
00004  * This class tracks the state of the seven input
00005  * buttons. It exposes (void) callback methods to
00006  * flag each button as active or not and provides
00007  * a mapping between key combinations and the
00008  * alphabet for text input.
00009  *
00010  */
00011 
00012 #ifndef KEYMANAGER
00013 #define KEYMANAGER
00014 
00015 #include <string>
00016 #include <ctype.h>
00017 
00018 class KeyManager {
00019 private:
00020     // key definitions
00021     bool keyModifier;
00022     bool keySpace;
00023     bool key0;
00024     bool key1;
00025     bool key2;
00026     bool key3;
00027     bool key4;
00028     
00029     // static character map and constants
00030     static char characters[27];
00031     static char space;
00032     static char unknown;
00033         
00034 public:
00035     
00036     // constructor
00037     KeyManager() {
00038         keyModifier = false;
00039         keySpace = false;
00040         key0 = false;
00041         key1 = false;
00042         key2 = false;
00043         key3 = false;
00044         key4 = false;
00045     }
00046     
00047     // DEBUG: return the status of which keys are pressed
00048     char* getStatusString() {
00049         std::string status = "the following keys are pressed:";
00050         if (key0) {
00051            status += " 0";
00052         }
00053         if (key1) {
00054            status += " 1";
00055         }
00056         if (key2) {
00057            status += " 2";
00058         }
00059         if (key3) {
00060            status += " 3";
00061         }
00062         if (key4) {
00063            status += " 4";
00064         }
00065         status += "\n";
00066         return (char*)status.c_str(); 
00067     }
00068     
00069     // get the numeric code corresponding to
00070     // the currently pressed keys.
00071     int getCode() {
00072         int result = 0;
00073         if (key0) {
00074            result = result | 1;
00075         }
00076         if (key1) {
00077            result = result | 2;
00078         }
00079         if (key2) {
00080            result = result | 4;
00081         }
00082         if (key3) {
00083            result = result | 8;
00084         }
00085         if (key4) {
00086            result = result | 16;
00087         }
00088         return result;
00089     }
00090     
00091     // map the current code to its character
00092     char getCharacter() {
00093         if (keySpace) {
00094             return space;
00095         } else {
00096             int code = this->getCode();
00097             if (code < 28 && !keyModifier) {
00098                 return characters[code-1];   
00099             } else if (code < 28 && keyModifier) {
00100                 return toupper(characters[code-1]);
00101             } else {
00102                 return unknown;   
00103             }
00104         }
00105     }
00106     
00107     // check whether any of the character keys or the space
00108     // key are pressed
00109     bool keysPressed() {
00110         if (key0 || key1 || key2 || key3 || key4 || keySpace) {
00111             return true;   
00112         }
00113         return false;
00114     }
00115     
00116     // Interrupt callback functions
00117     void keyMOn() { keyModifier = true; }
00118     void keyMOff() { keyModifier = false; }
00119     void keySpaceOn() { keySpace = true; }
00120     void keySpaceOff() { keySpace = false; }
00121     void key0On() { key0 = true; }
00122     void key0Off() { key0 = false; }
00123     void key1On() { key1 = true; }
00124     void key1Off() { key1 = false; }
00125     void key2On() { key2 = true; }
00126     void key2Off() { key2 = false; }
00127     void key3On() { key3 = true; }
00128     void key3Off() { key3 = false; }
00129     void key4On() { key4 = true; }
00130     void key4Off() { key4 = false; }
00131 };
00132 
00133 // define statics
00134 char KeyManager::characters[27] = {'a','b','c','d','e','f','g',
00135     'h','i','j','k','l','m','n','o','p','q','r','s','t',
00136     'u','v','w','x','y','z','.' };
00137 char KeyManager::space = ' ';
00138 char KeyManager::unknown = '?';
00139 
00140 #endif