TRACK.C
/******************************************************************************\
* This is a part of the Microsoft Source Code Samples.
* Copyright 1993 - 1998 Microsoft Corporation.
* 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.
\******************************************************************************/
/***************************************************************************
* *
* MODULE : track.c *
* *
* PURPOSE : Generic tracking code. *
* *
***************************************************************************/
#include <windows.h>
#include "track.h"
RECT rcTrack;
RECT rcDelta;
POINT ptOrg;
POINT ptPrev;
DWORD fsTrack;
RECT rcBoundary;
INT cxMinTrack;
INT cyMinTrack;
VOID DrawTrackRect(HWND hwnd, LPRECT prcOld, LPRECT prcNew);
VOID HorzUpdate(HDC hdc, INT yOld, INT yNew, INT x1Old, INT x1New, INT x2Old,
INT x2New);
VOID VertUpdate(HDC hdc, INT xOld, INT xNew, INT y1Old, INT y1New, INT y2Old,
INT y2New);
LONG APIENTRY TrackingWndProc(HWND hwnd, DWORD msg, WPARAM wParam, LPARAM lParam);
/****************************************************************************
* *
* FUNCTION : TrackRect() *
* *
* PURPOSE : Implements functionality similiar to the PM WinTrackRect() *
* *
* RETURNS : TRUE on success, FALSE if tracking was canceled. *
* prcResult contains the resulting rectangle. *
* *
****************************************************************************/
BOOL TrackRect(
HANDLE hInst,
HWND hwnd, // bounding window
INT left, // rectangle to track in bounding window coords.
INT top,
INT right,
INT bottom,
INT cxMin,
INT cyMin,
DWORD fs,
LPRECT prcResult) // result rect in bounding window coords.
{
static BOOL fTracking = 0;
FARPROC lpOrgWndProc, lpTrackWndProc;
HWND hwndOldCapture, hwndOldFocus;
MSG msg;
if (fTracking)
return FALSE;
fTracking = TRUE;
lpOrgWndProc = (FARPROC)GetWindowLong(hwnd, GWL_WNDPROC);
lpTrackWndProc = MakeProcInstance((FARPROC)TrackingWndProc, hInst);
SetWindowLong(hwnd, GWL_WNDPROC, (DWORD)lpTrackWndProc);
hwndOldCapture = GetCapture();
SetCapture(hwnd);
hwndOldFocus = SetFocus(hwnd);
UpdateWindow(hwnd);
GetCursorPos(&ptOrg);
ScreenToClient(hwnd, &ptOrg);
if (fs & TF_SETPOINTERPOS) {
if (fs & TF_LEFT && fs & TF_RIGHT)
ptOrg.x = (left + right) / 2;
else if (fs & TF_LEFT)
ptOrg.x = left;
else if (fs & TF_RIGHT)
ptOrg.x = right;
if (fs & TF_TOP && fs & TF_BOTTOM)
ptOrg.y = (top + bottom) / 2;
else if (fs & TF_TOP)
ptOrg.y = top;
else if (fs & TF_BOTTOM)
ptOrg.y = bottom;
ClientToScreen(hwnd, &ptOrg);
SetCursorPos(ptOrg.x, ptOrg.y);
ScreenToClient(hwnd, &ptOrg);
}
ptPrev = ptOrg;
cxMinTrack = cxMin;
cyMinTrack = cyMin;
GetClientRect(hwnd, &rcBoundary);
fsTrack = fs;
SetRect(&rcTrack, left, top, right, bottom);
SetRect(&rcDelta, left - ptOrg.x, top - ptOrg.y, right - ptOrg.x,
bottom - ptOrg.y);
DrawTrackRect(hwnd, &rcTrack, NULL);
while (GetMessage(&msg, NULL, 0, 0))
DispatchMessage(&msg);
DrawTrackRect(hwnd, &rcTrack, NULL);
SetWindowLong(hwnd, GWL_WNDPROC, (DWORD)lpOrgWndProc);
FreeProcInstance(lpTrackWndProc);
SetFocus(hwndOldFocus);
SetCapture(hwndOldCapture);
CopyRect(prcResult, &rcTrack);
fTracking = FALSE;
}
/****************************************************************************
* *
* FUNCTION : DrawTrackRect() *
* *
* PURPOSE : XOR draws whats needed to move a selection from prcOld to *
* prcNew. If prcNew == NULL this is considered a *
* first-time draw or last time erase. *
* *
****************************************************************************/
VOID DrawTrackRect(
HWND hwnd,
LPRECT prcOld,
LPRECT prcNew)
{
HDC hdc;
hdc = GetDC(hwnd);
SetROP2(hdc, R2_NOT);
// erase/draw the whole thing
MoveToEx(hdc, prcOld->left, prcOld->top, NULL);
LineTo(hdc, prcOld->right, prcOld->top);
LineTo(hdc, prcOld->right, prcOld->bottom);
LineTo(hdc, prcOld->left, prcOld->bottom);
LineTo(hdc, prcOld->left, prcOld->top);
if (prcNew) {
MoveToEx(hdc, prcNew->left, prcNew->top, NULL);
LineTo(hdc, prcNew->right, prcNew->top);
LineTo(hdc, prcNew->right, prcNew->bottom);
LineTo(hdc, prcNew->left, prcNew->bottom);
LineTo(hdc, prcNew->left, prcNew->top);
}
ReleaseDC(hwnd, hdc);
}
/****************************************************************************
* *
* FUNCTION : TrackingWndProc() *
* *
* PURPOSE : Window procedure that subclasses the given parent window. *
* This handles the mouse tracking and rectangle updates. *
* *
****************************************************************************/
LONG APIENTRY TrackingWndProc(
HWND hwnd,
DWORD msg,
WPARAM wParam,
LPARAM lParam)
{
switch (msg) {
case WM_MOUSEMOVE:
{
RECT rcNow, rcTest;
if (ptPrev.x == (short)LOWORD(lParam) && ptPrev.y == (short)HIWORD(lParam))
return 0;
CopyRect(&rcNow, &rcTrack);
if (fsTrack & TF_LEFT)
rcNow.left = (short)LOWORD(lParam) + rcDelta.left;
if (fsTrack & TF_RIGHT)
rcNow.right = (short)LOWORD(lParam) + rcDelta.right;
if (fsTrack & TF_TOP)
rcNow.top = (short)HIWORD(lParam) + rcDelta.top;
if (fsTrack & TF_BOTTOM)
rcNow.bottom = (short)HIWORD(lParam) + rcDelta.bottom;
if (rcNow.left > rcNow.right - cxMinTrack)
if (fsTrack & TF_LEFT)
rcNow.left = rcNow.right - cxMinTrack;
else
rcNow.right = rcNow.left + cxMinTrack;
if (rcNow.top > rcNow.bottom - cyMinTrack)
if (fsTrack & TF_TOP)
rcNow.top = rcNow.bottom - cyMinTrack;
else
rcNow.bottom = rcNow.top + cyMinTrack;
if (fsTrack & TF_ALLINBOUNDARY) {
if ((fsTrack & TF_MOVE) == TF_MOVE) {
IntersectRect(&rcTest, &rcNow, &rcBoundary);
if (!EqualRect(&rcTest, &rcNow)) {
if (rcNow.left < rcBoundary.left)
OffsetRect(&rcNow, rcBoundary.left - rcNow.left, 0);
if (rcNow.right > rcBoundary.right)
OffsetRect(&rcNow, rcBoundary.right - rcNow.right, 0);
if (rcNow.top < rcBoundary.top)
OffsetRect(&rcNow, 0, rcBoundary.top - rcNow.top);
if (rcNow.bottom > rcBoundary.bottom)
OffsetRect(&rcNow, 0, rcBoundary.bottom - rcNow.bottom);
}
} else
IntersectRect(&rcNow, &rcNow, &rcBoundary);
}
if (EqualRect(&rcNow, &rcTrack))
return 0;
DrawTrackRect(hwnd, &rcTrack, &rcNow);
CopyRect(&rcTrack, &rcNow);
((ptPrev).x = ((*((POINTS *)&(lParam)))).x, (ptPrev).y = ((*((POINTS *)&(lParam)))).y);
}
break;
case WM_LBUTTONUP:
SendMessage(hwnd, WM_MOUSEMOVE, wParam, lParam);
PostMessage(hwnd, WM_QUIT, 0, 0); // pop out of modal loop
return 0;
break;
default:
return(DefWindowProc(hwnd, msg, wParam, lParam));
break;
}
return 0;
}