_C PROGRAMMING COLUMN_
by Al Stevens

[LISTING ONE]

// ---------- desktop.h
#ifndef DESKTOP_H
#define DESKTOP_H

#include "screen.h"
#include "cursor.h"
#include "keyboard.h"
#include "mouse.h"
#include "speaker.h"
#include "clock.h"

class DFWindow;

class DeskTop {
    DFWindow *apwnd;        // application window
    DFWindow *infocus;      // current window with the focus
    DFWindow *firstcapture; // first window to capture the focus
    DFWindow *focuscapture; // current window with captured focus
    // ------- the desktop devices
    Screen   sysscreen;     // the system screen
    Mouse    sysmouse;      // the system mouse
    Keyboard syskeyboard;   // the system keyboard
    Cursor   syscursor;     // the system cursor
    Clock    sysclock;      // the system clock
    Speaker  sysspeaker;    // the system speaker
public:
    DeskTop();
    ~DeskTop();
    DFWindow *ApplWnd() { return apwnd; }
    void SetApplication(DFWindow *ApWnd) { apwnd = ApWnd; }
    Bool DispatchEvents();
    DFWindow *InFocus()      { return infocus; }
    DFWindow *FocusCapture() { return focuscapture; }
    DFWindow *FirstCapture() { return firstcapture; }
    void SetFocus(DFWindow *wnd) { infocus = wnd; }
    void SetFocusCapture(DFWindow *wnd) { focuscapture = wnd; }
    void SetFirstCapture(DFWindow *wnd) { firstcapture = wnd; }
    // ------- the desktop devices
    Mouse&    mouse()       { return sysmouse;    }
    Screen&   screen()      { return sysscreen;   }
    Keyboard& keyboard()    { return syskeyboard; }
    Cursor&   cursor()      { return syscursor;   }
    Clock&    clock()       { return sysclock;    }
    Speaker&  speaker()     { return sysspeaker;  }
};
extern DeskTop desktop;

#endif


[LISTING TWO]

// ----------- screen.h
#ifndef SCREEN_H
#define SCREEN_H

#include <dos.h>
#include "dflatdef.h"
#include "rectangl.h"

class Screen    {
    unsigned address;
    unsigned mode;
    unsigned page;
    unsigned height;
    unsigned width;
    union REGS regs;
    // ---- compute video offset address
    unsigned vad(int x, int y) { return y * (width*2) + x*2; }
public:
    Screen();
    unsigned Height() { return height; }
    unsigned Width()  { return width; }
    unsigned Page()   { return page; }
    Bool isEGA();
    Bool isVGA();
    Bool isMono() { return (Bool) (mode == 7); }
    Bool isText() { return (Bool) (mode < 4);  }
    void Scroll(Rect &rc, int d, int fg, int bg);
    unsigned int GetVideoChar(int x, int y);
    void PutVideoChar(int x, int y, unsigned int c);
    void WriteVideoString(char *s,int x,int y,int fg,int bg);
    void SwapBuffer(Rect &rc, char *bf,
        Bool Hiding, Bool HasShadow, Bool isFrame);
    void GetBuffer(Rect &rc, char *bf);
    void PutBuffer(Rect &rc, char *bf);
};
const int VIDEO = 0x10;
inline int clr(int fg, int bg)
{
    return fg | (bg << 4);
}
#endif




[LISTING THREE]

// ---------- mouse.h
#ifndef MOUSE_H
#define MOUSE_H

#include <dos.h>
#include "dfwindow.h"
#include "timer.h"

class Mouse    {
    Bool installed;      // True = mouse is installed
    char *statebuffer;   // mouse state buffer
    Timer doubletimer;   // mouse double-click timer
    Timer delaytimer;    // mouse typematic click timer
    int prevx;           // previous mouse x coordinate
    int prevy;           // previous mouse y coordinate
    int clickx;          // click x position
    int clicky;          // click y position
    int releasex;        // release x position
    int releasey;        // release y position
    union REGS regs;
    DFWindow *MouseWindow(int mx, int my);
    void CallMouse(int m1,int m2=0,int m3=0,int m4=0,unsigned es=0);
    void DispatchRelease();
    void DispatchMove();
    void DispatchLeftButton();
public:
    Mouse();
    ~Mouse();
    Bool Installed() { return installed; }
    void GetPosition(int &x, int &y); // get mouse position
    void SetPosition(int x, int y);   // set mouse position
    Bool Moved();           // True if mouse has moved
    void Show();            // show the mouse cursor
    void Hide();            // hide the mouse cursor
    Bool LeftButton();     // True if left button is pressed
    Bool ButtonReleased(); // True if button was released
    void SetTravel(int minx, int maxx, int miny, int maxy);
    void DispatchEvent();
};
const int MOUSE          = 0x33;  // mouse interrupt vector
// -------- mouse commands
const int RESETMOUSE     =  0;
const int SHOWMOUSE      =  1;
const int HIDEMOUSE      =  2;
const int READMOUSE      =  3;
const int SETPOSITION    =  4;
const int BUTTONRELEASED =  6;
const int XLIMIT         =  7;
const int YLIMIT         =  8;
const int BUFFSIZE       = 21;
const int SAVESTATE      = 22;
const int RESTORESTATE   = 23;
// -------- timer delays for mouse repeat, double clicks
const int DELAYTICKS     =  1;
const int FIRSTDELAY     =  7;
const int DOUBLETICKS    =  5;

#endif



[LISTING FOUR]

// ------------- cursor.h
#ifndef CURSOR_H
#define CURSOR_H

// ------- video BIOS (0x10) functions
const int SETCURSORTYPE = 1;
const int SETCURSOR     = 2;
const int READCURSOR    = 3;
const int HIDECURSOR    = 0x20;

const int MAXSAVES = 50;  // depth of cursor save/restore stack
class Cursor {
    // --- cursor save/restore stack
    int cursorpos[MAXSAVES];
    int cursorshape[MAXSAVES];
    int cs;             // count of cursor saves in effect
    union REGS regs;
    void Cursor::GetCursor();
public:
    Cursor();
    ~Cursor();
    void SetPosition(int x, int y);
    void GetPosition(int &x, int &y);
    void SetType(unsigned t);
    void normalcursor() { SetType(0x0607); }
    void Hide();
    void Show();
    void Save();
    void Restore();
    void SwapStack();
};
inline void swap(int a, int b)
{
    int x = a;
    a = b;
    b = x;
}
#endif



[LISTING FIVE]

// ------------ keyboard.h
#ifndef KEYBOARD_H
#define KEYBOARD_H

#include <dos.h>
#include "dflatdef.h"

class Keyboard    {
    union REGS regs;
    int shift;
public:
    Keyboard() { shift = GetShift(); }
    Bool ShiftChanged();
    int ShiftState() { return shift = GetShift(); }
    int AltConvert(int);
    int GetKey();
    int GetShift();
    Bool KeyHit();
    void clearBIOSbuffer();
    void DispatchEvent();
};
const int KEYBOARDVECT = 9;
const int KEYBOARDPORT = 0x60;

inline void Keyboard::clearBIOSbuffer()
{
    *(int far *)(MK_FP(0x40,0x1a)) = 
    *(int far *)(MK_FP(0x40,0x1c));
}
// ----- keyboard BIOS (0x16) functions
const int KEYBRD = 0x16;
const int READKB = 0;
const int KBSTAT = 1;

const int ZEROFLAG = 0x40;
const int OFFSET = 0x1000;

const int RUBOUT = 8;
const int BELL   = 7;
const int ESC    = 27;
const unsigned F1          = (187+OFFSET);
const unsigned F8          = (194+OFFSET);
const unsigned SHIFT_F8    = (219+OFFSET);
const unsigned F10         = (196+OFFSET);
const unsigned HOME        = (199+OFFSET);
const unsigned UP          = (200+OFFSET);
const unsigned PGUP        = (201+OFFSET);
const unsigned BS          = (203+OFFSET);
const unsigned FWD         = (205+OFFSET);
const unsigned END         = (207+OFFSET);
const unsigned DN          = (208+OFFSET);
const unsigned PGDN        = (209+OFFSET);
const unsigned INS         = (210+OFFSET);
const unsigned DEL         = (211+OFFSET);
const unsigned CTRL_HOME   = (247+OFFSET);
const unsigned CTRL_PGUP   = (132+OFFSET);
const unsigned CTRL_BS     = (243+OFFSET);
const unsigned CTRL_FIVE   = (143+OFFSET);
const unsigned CTRL_FWD    = (244+OFFSET);
const unsigned CTRL_END    = (245+OFFSET);
const unsigned CTRL_PGDN   = (246+OFFSET);
const unsigned SHIFT_HT    = (143+OFFSET);
const unsigned ALT_A       = (158+OFFSET);
const unsigned ALT_B       = (176+OFFSET);
const unsigned ALT_C       = (174+OFFSET);
const unsigned ALT_D       = (160+OFFSET);
const unsigned ALT_E       = (146+OFFSET);
const unsigned ALT_F       = (161+OFFSET);
const unsigned ALT_G       = (162+OFFSET);
const unsigned ALT_H       = (163+OFFSET);
const unsigned ALT_I       = (151+OFFSET);
const unsigned ALT_J       = (164+OFFSET);
const unsigned ALT_K       = (165+OFFSET);
const unsigned ALT_L       = (166+OFFSET);
const unsigned ALT_M       = (178+OFFSET);
const unsigned ALT_N       = (177+OFFSET);
const unsigned ALT_O       = (152+OFFSET);
const unsigned ALT_P       = (153+OFFSET);
const unsigned ALT_Q       = (144+OFFSET);
const unsigned ALT_R       = (147+OFFSET);
const unsigned ALT_S       = (159+OFFSET);
const unsigned ALT_T       = (148+OFFSET);
const unsigned ALT_U       = (150+OFFSET);
const unsigned ALT_V       = (175+OFFSET);
const unsigned ALT_W       = (145+OFFSET);
const unsigned ALT_X       = (173+OFFSET);
const unsigned ALT_Y       = (149+OFFSET);
const unsigned ALT_Z       = (172+OFFSET);
const unsigned ALT_1      = (0xf8+OFFSET);
const unsigned ALT_2      = (0xf9+OFFSET);
const unsigned ALT_3      = (0xfa+OFFSET);
const unsigned ALT_4      = (0xfb+OFFSET);
const unsigned ALT_5      = (0xfc+OFFSET);
const unsigned ALT_6      = (0xfd+OFFSET);
const unsigned ALT_7      = (0xfe+OFFSET);
const unsigned ALT_8      = (0xff+OFFSET);
const unsigned ALT_9      = (0x80+OFFSET);
const unsigned ALT_0      = (0x81+OFFSET);
const unsigned ALT_HYPHEN = (130+OFFSET);
const unsigned CTRL_F4    = (225+OFFSET);
const unsigned ALT_F4     = (235+OFFSET);
const unsigned ALT_F6     = (237+OFFSET);

enum {CTRL_A=1,CTRL_B,CTRL_C,CTRL_D,CTRL_E,CTRL_F,CTRL_G,CTRL_H,
        CTRL_I,CTRL_J,CTRL_K,CTRL_L,CTRL_M,CTRL_N,CTRL_O,CTRL_P,
        CTRL_Q,CTRL_R,CTRL_S,CTRL_T,CTRL_U,CTRL_V,CTRL_W,CTRL_X,
        CTRL_Y,CTRL_Z };
// ------- BIOS shift key mask values
const int RIGHTSHIFT = 0x01;
const int LEFTSHIFT  = 0x02;
const int CTRLKEY    = 0x04;
const int ALTKEY     = 0x08;
const int SCROLLLOCK = 0x10;
const int NUMLOCK    = 0x20;
const int CAPSLOCK   = 0x40;
const int INSERTKEY  = 0x80;

#endif


[LISTING SIX]

// --------- speaker.h
#ifndef SPEAKER_H
#define SPEAKER_H

class Speaker    {
    void Wait(int n);
public:
    void Beep();
};
const int FREQUENCY = 100;
const long COUNT = 1193280L / FREQUENCY;

#endif



[LISTING SEVEN]

// --------- clock.h
#ifndef CLOCK_H
#define CLOCK_H

#include "timer.h"

class Clock    {
    Timer clocktimer;
public:
    Clock();
    void DispatchEvent();
};
#endif