CURSOR.C
/******************************************************************************\
* This is a part of the Microsoft Source Code Samples.
* Copyright 1993 - 1998 Microsoft Corp.
* All rights reserved.
* This source code is only intended as a supplement to
* Microsoft Development Tools and/or WinHelp documentation.
* See these sources for detailed information regarding the
* Microsoft samples programs.
\******************************************************************************/
/****************************************************************************
PROGRAM: Cursor.c
PURPOSE: Demonstrates how to manipulate a cursor and select a region
FUNCTIONS:
WinMain() - calls initialization function, processes message loop
InitApplication() - initializes window data and registers window
InitInstance() - saves instance handle and creates main window
MainWndProc() - processes messages
About() - processes messages for "About" dialog box
sieve() - time consuming function, generates primes
****************************************************************************/
#include <windows.h>
#include <string.h>
#include "cursor.h"
HANDLE hInst;
CHAR str[255]; /* general-purpose string buffer */
HCURSOR hSaveCursor; /* handle to current cursor */
HCURSOR hHourGlass; /* handle to hourglass cursor */
BOOL bTrack = FALSE; /* TRUE if left button clicked */
INT OrgX = 0, OrgY = 0; /* original cursor position */
INT PrevX = 0, PrevY = 0; /* current cursor position */
INT X = 0, Y = 0; /* last cursor position */
RECT Rect; /* selection rectangle */
MPOINT ptCursor; /* x and y coordinates of cursor */
INT repeat = 1; /* repeat count of keystroke */
/****************************************************************************
FUNCTION: WinMain(HANDLE, HANDLE, LPSTR, int)
PURPOSE: calls initialization function, processes message loop
****************************************************************************/
int APIENTRY WinMain(
HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow
)
{
MSG msg; /* message */
UNREFERENCED_PARAMETER( lpCmdLine );
if (!hPrevInstance)
if (!InitApplication(hInstance))
return (FALSE);
if (!InitInstance(hInstance, nCmdShow))
return (FALSE);
MessageBox (
GetFocus ()
, "Use the mouse button in this program for an example of graphics "
"selection, or the <Enter> key for an example of "
"using a special cursor to reflect a program state."
, "Cursor Sample Application"
, MB_ICONASTERISK | MB_OK
);
while (GetMessage(&msg, NULL, 0, 0)) {
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return (msg.wParam);
}
/****************************************************************************
FUNCTION: InitApplication(HANDLE)
PURPOSE: Initializes window data and registers window class
****************************************************************************/
BOOL InitApplication(HANDLE hInstance)
{
WNDCLASS wc;
wc.style = 0;
wc.lpfnWndProc = (WNDPROC) MainWndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(hInstance, "bullseye");
wc.hbrBackground = GetStockObject(WHITE_BRUSH);
wc.lpszMenuName = "CursorMenu";
wc.lpszClassName = "CursorWClass";
return (RegisterClass(&wc));
}
/****************************************************************************
FUNCTION: InitInstance(HANDLE, int)
PURPOSE: Saves instance handle and creates main window
****************************************************************************/
BOOL InitInstance(
HANDLE hInstance,
INT nCmdShow)
{
HWND hWnd;
hInst = hInstance;
strcpy(str,"");
hHourGlass = LoadCursor(NULL, IDC_WAIT);
hWnd = CreateWindow(
"CursorWClass",
"Cursor Sample Application",
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
NULL,
NULL,
hInstance,
NULL
);
if (!hWnd)
return (FALSE);
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
return (TRUE);
}
/****************************************************************************
FUNCTION: MainWndProc(HWND, unsigned, WORD, LONG)
PURPOSE: Processes messages
MESSAGES:
WM_COMMAND - application menu (About dialog box)
WM_CHAR - ASCII key value received
WM_LBUTTONDOWN - left mouse button
WM_MOUSEMOVE - mouse movement
WM_LBUTTONUP - left button released
WM_KEYDOWN - key pressed
WM_KEYUPS - key released
WM_PAINT - update window
WM_DESTROY - destroy window
COMMENTS:
When the left mouse button is pressed, btrack is set to TRUE so that
the code for WM_MOUSEMOVE will keep track of the mouse and update
the box accordingly. Once the button is released, btrack is set to
FALSE, and the current position is saved. Holding the SHIFT key
while pressing the left button will extend the current box rather
then erasing it and starting a new one.
When an arrow key is pressed, the cursor is repositioned in the
direction of the arrow key. A repeat count is kept so that the
longer the user holds down the arrow key, the faster it will move.
As soon as the key is released, the repeat count is set to 1 for
normal cursor movement.
****************************************************************************/
LONG APIENTRY MainWndProc(HWND hWnd, UINT message, UINT wParam, LONG lParam)
{
POINT pt;
HDC hDC;
switch (message) {
case WM_COMMAND:
// LOWORD added for portability
if (LOWORD(wParam) == IDM_ABOUT) {
DialogBox(hInst,
"AboutBox",
hWnd,
About);
break;
}
else
return (DefWindowProc(hWnd, message, wParam, lParam));
case WM_CHAR:
if (wParam == '\r') {
SetCapture(hWnd);
/* Set the cursor to an hourglass */
hSaveCursor = SetCursor(hHourGlass);
strcpy (str, "Calculating prime numbers...");
InvalidateRect (hWnd, NULL, TRUE);
UpdateWindow (hWnd);
wsprintf(str, "Calculated %d primes. ", sieve());
InvalidateRect (hWnd, NULL, TRUE);
UpdateWindow (hWnd);
SetCursor(hSaveCursor); /* Restores previous cursor */
ReleaseCapture();
}
break;
case WM_LBUTTONDOWN:
bTrack = TRUE;
strcpy (str, "");
PrevX = LOWORD(lParam);
PrevY = HIWORD(lParam);
if (!(wParam & MK_SHIFT)) { /* If shift key is not pressed */
OrgX = LOWORD(lParam);
OrgY = HIWORD(lParam);
}
InvalidateRect (hWnd, NULL, TRUE);
UpdateWindow (hWnd);
/* Capture all input even if the mouse goes outside of window */
SetCapture(hWnd);
break;
case WM_MOUSEMOVE:
{
RECT rectClient;
INT NextX;
INT NextY;
if (bTrack) {
NextX = (SHORT)LOWORD(lParam);
NextY = (SHORT)HIWORD(lParam);
/* Do not draw outside the window's client area */
GetClientRect (hWnd, &rectClient);
if (NextX < rectClient.left) {
NextX = rectClient.left;
} else if (NextX >= rectClient.right) {
NextX = rectClient.right - 1;
}
if (NextY < rectClient.top) {
NextY = rectClient.top;
} else if (NextY >= rectClient.bottom) {
NextY = rectClient.bottom - 1;
}
/* If the mouse position has changed, then clear the */
/* previous rectangle and draw the new one. */
if ((NextX != PrevX) || (NextY != PrevY)) {
hDC = GetDC(hWnd);
SetROP2(hDC, R2_NOT); /* Erases the previous box */
MoveToEx(hDC, OrgX, OrgY, NULL);
LineTo(hDC, OrgX, PrevY);
LineTo(hDC, PrevX, PrevY);
LineTo(hDC, PrevX, OrgY);
LineTo(hDC, OrgX, OrgY);
/* Get the current mouse position */
PrevX = NextX;
PrevY = NextY;
MoveToEx(hDC, OrgX, OrgY, NULL); /* Draws the new box */
LineTo(hDC, OrgX, PrevY);
LineTo(hDC, PrevX, PrevY);
LineTo(hDC, PrevX, OrgY);
LineTo(hDC, OrgX, OrgY);
ReleaseDC(hWnd, hDC);
}
}
}
break;
case WM_LBUTTONUP:
bTrack = FALSE; /* No longer creating a selection */
ReleaseCapture(); /* Releases hold on mouse input */
X = LOWORD(lParam); /* Saves the current value */
Y = HIWORD(lParam);
break;
case WM_KEYDOWN:
if (wParam != VK_LEFT && wParam != VK_RIGHT
&& wParam != VK_UP && wParam != VK_DOWN)
break;
MPOINT2POINT(ptCursor, pt);
GetCursorPos(&pt);
/* Convert screen coordinates to client coordinates */
ScreenToClient(hWnd, &pt);
POINT2MPOINT(pt, ptCursor);
repeat++; /* Increases the repeat rate */
switch (wParam) {
/* Adjust cursor position according to which key was pressed. */
case VK_LEFT:
ptCursor.x -= repeat;
break;
case VK_RIGHT:
ptCursor.x += repeat;
break;
case VK_UP:
ptCursor.y -= repeat;
break;
case VK_DOWN:
ptCursor.y += repeat;
break;
}
/* Get the client boundaries */
GetClientRect(hWnd, &Rect);
/* Do not draw outside the window's client area */
MPOINT2POINT(ptCursor, pt);
if (pt.x >= Rect.right)
pt.x = Rect.right - 1;
else if (pt.x < Rect.left)
pt.x = Rect.left;
if (pt.y >= Rect.bottom)
pt.y = Rect.bottom - 1;
else if (pt.y < Rect.top)
pt.y = Rect.top;
/* Convert the coordinates to screen coordinates */
ClientToScreen(hWnd, &pt);
SetCursorPos(pt.x, pt.y);
break;
case WM_KEYUP:
repeat = 1; /* Clears the repeat count. */
break;
case WM_ACTIVATE:
if (!GetSystemMetrics(SM_MOUSEPRESENT)) {
if (!HIWORD(wParam)) {
// LOWORD added for portability
if (LOWORD(wParam)) {
SetCursor(LoadCursor(hInst, "bullseye"));
pt.x = X;
pt.y = Y;
ClientToScreen(hWnd, &pt);
SetCursorPos(pt.x, pt.y);
}
ShowCursor(wParam);
}
}
break;
case WM_PAINT:
{
PAINTSTRUCT ps;
hDC = BeginPaint (hWnd, &ps);
if (OrgX != PrevX || OrgY != PrevY) {
MoveToEx(hDC, OrgX, OrgY, NULL);
LineTo(hDC, OrgX, PrevY);
LineTo(hDC, PrevX, PrevY);
LineTo(hDC, PrevX, OrgY);
LineTo(hDC, OrgX, OrgY);
}
TextOut (hDC, 1, 1, str, strlen (str));
EndPaint (hWnd, &ps);
}
break;
case WM_DESTROY:
PostQuitMessage(0);
break;
default:
return (DefWindowProc(hWnd, message, wParam, lParam));
}
return (0);
}
/****************************************************************************
FUNCTION: About(HWND, unsigned, WORD, LONG)
PURPOSE: Processes messages for "About" dialog box
MESSAGES:
WM_INITDIALOG - initialize dialog box
WM_COMMAND - Input received
****************************************************************************/
BOOL APIENTRY About(HWND hDlg, UINT message, UINT wParam, LONG lParam)
{
switch (message) {
case WM_INITDIALOG:
return (TRUE);
case WM_COMMAND:
// LOWORD added for portability
if (LOWORD(wParam) == IDOK
|| LOWORD(wParam) == IDCANCEL) {
EndDialog(hDlg, TRUE);
return (TRUE);
}
break;
}
return (FALSE);
UNREFERENCED_PARAMETER(lParam);
}
/****************************************************************************
FUNCTION: Sieve()
PURPOSE: Example of time consuming process
COMMENTS:
Sieve of Eratosthenes, BYTE, Volume 8, Number 1, by Jim Gilbreath
and Gary Gilbreath. Code changed to give correct results.
One could return the count, and after restoring the cursor, use
sprintf() to copy the information to a string which could then be
put up in a MessageBox().
****************************************************************************/
#define NITER 20 /* number of iterations */
#define SIZE 8190
CHAR flags[SIZE+1]={ 0};
INT sieve() {
INT i,k;
INT iter, count;
for (iter = 1; iter <= NITER; iter++) { /* Does sieve NITER times */
count = 0;
for (i = 0; i <= SIZE; i++) /* Sets all flags TRUE */
flags[i] = TRUE;
for (i = 2; i <= SIZE; i++) {
if (flags[i] ) { /* Found a prime? */
for (k = i + i; k <= SIZE; k += i)
flags[k] = FALSE; /* Cancelsits multiples */
count++;
}
}
}
return (count);
}