windows/scroll.c

   1 /*
   2  * Scroll windows and DCs
   3  *
   4  * Copyright  David W. Metcalfe, 1993
   5  *
   6  */
   7
   8 static char Copyright[] = "Copyright  David W. Metcalfe, 1993";
   9
  10 #include <stdlib.h>
  11 #include "windows.h"
  12 #include "gdi.h"
  13 #include "scroll.h"
  14 #include "stddebug.h"
  15 /* #define DEBUG_SCROLL */
  16 #include "debug.h"
  17
  18
  19 static int RgnType;
  20
  21
  22 /*************************************************************************
  23  *             ScrollWindow         (USER.61)
  24  */
  25
  26 void ScrollWindow(HWND hwnd, short dx, short dy, LPRECT rect, LPRECT clipRect)
  27 {
  28     HDC hdc;
  29     HRGN hrgnUpdate;
  30     RECT rc, cliprc;
  31
  32     dprintf_scroll(stddeb,"ScrollWindow: dx=%d, dy=%d, rect=%d,%d,%d,%d\n",
  33            dx, dy, rect->left, rect->top, rect->right, rect->bottom);
  34
  35     hdc = GetDC(hwnd);
  36
  37     if (rect == NULL)
  38         GetClientRect(hwnd, &rc);
  39     else
  40         CopyRect(&rc, rect);
  41     if (clipRect == NULL)
  42         GetClientRect(hwnd, &cliprc);
  43     else
  44         CopyRect(&cliprc, clipRect);
  45
  46     hrgnUpdate = CreateRectRgn(0, 0, 0, 0);
  47     ScrollDC(hdc, dx, dy, &rc, &cliprc, hrgnUpdate, NULL);
  48     InvalidateRgn(hwnd, hrgnUpdate, TRUE);
  49     ReleaseDC(hwnd, hdc);
  50 }
  51
  52
  53 /*************************************************************************
  54  *             ScrollDC         (USER.221)
  55  */
  56
  57 BOOL ScrollDC(HDC hdc, short dx, short dy, LPRECT rc, LPRECT cliprc,
  58               HRGN hrgnUpdate, LPRECT rcUpdate)
  59 {
  60     HRGN hrgnClip, hrgn1, hrgn2;
  61     POINT src, dest;
  62     short width, height;
  63     DC *dc = (DC *)GDI_GetObjPtr(hdc, DC_MAGIC);
  64
  65     dprintf_scroll(stddeb, "ScrollDC: dx=%d, dy=%d, rc=%d,%d,%d,%d\n", dx, dy,
  66            rc->left, rc->top, rc->right, rc->bottom);
  67
  68     if (rc == NULL)
  69         return FALSE;
  70
  71     if (cliprc)
  72     {
  73         hrgnClip = CreateRectRgnIndirect(cliprc);
  74         SelectClipRgn(hdc, hrgnClip);
  75     }
  76
  77     if (dx > 0)
  78     {
  79         src.x = XDPTOLP(dc, rc->left);
  80         dest.x = XDPTOLP(dc, rc->left + abs(dx));
  81     }
  82     else
  83     {
  84         src.x = XDPTOLP(dc, rc->left + abs(dx));
  85         dest.x = XDPTOLP(dc, rc->left);
  86     }
  87     if (dy > 0)
  88     {
  89         src.y = YDPTOLP(dc, rc->top);
  90         dest.y = YDPTOLP(dc, rc->top + abs(dy));
  91     }
  92     else
  93     {
  94         src.y = YDPTOLP(dc, rc->top + abs(dy));
  95         dest.y = YDPTOLP(dc, rc->top);
  96     }
  97
  98     width = rc->right - rc->left - abs(dx);
  99     height = rc->bottom - rc->top - abs(dy);
 100
 101     if (!BitBlt(hdc, dest.x, dest.y, width, height, hdc, src.x, src.y,
 102                 SRCCOPY))
 103         return FALSE;
 104
 105     if (hrgnUpdate)
 106     {
 107         if (dx > 0)
 108             hrgn1 = CreateRectRgn(rc->left, rc->top, rc->left+dx, rc->bottom);
 109         else if (dx < 0)
 110             hrgn1 = CreateRectRgn(rc->right+dx, rc->top, rc->right,
 111                                   rc->bottom);
 112         else
 113             hrgn1 = CreateRectRgn(0, 0, 0, 0);
 114
 115         if (dy > 0)
 116             hrgn2 = CreateRectRgn(rc->left, rc->top, rc->right, rc->top+dy);
 117         else if (dy < 0)
 118             hrgn2 = CreateRectRgn(rc->left, rc->bottom+dy, rc->right,
 119                                   rc->bottom);
 120         else
 121             hrgn2 = CreateRectRgn(0, 0, 0, 0);
 122
 123         RgnType = CombineRgn(hrgnUpdate, hrgn1, hrgn2, RGN_OR);
 124     }
 125
 126     if (rcUpdate) GetRgnBox( hrgnUpdate, rcUpdate );
 127     return TRUE;
 128 }
 129
 130
 131 /*************************************************************************
 132  *             ScrollWindowEx       (USER.319)
 133  */
 134
 135 int ScrollWindowEx(HWND hwnd, short dx, short dy, LPRECT rect, LPRECT clipRect,
 136                    HRGN hrgnUpdate, LPRECT rcUpdate, WORD flags)
 137 {
 138     HDC hdc;
 139     RECT rc, cliprc;
 140
 141     dprintf_scroll(stddeb,"ScrollWindowEx: dx=%d, dy=%d, rect=%d,%d,%d,%d\n",
 142            dx, dy, rect->left, rect->top, rect->right, rect->bottom);
 143
 144     hdc = GetDC(hwnd);
 145
 146     if (rect == NULL)
 147         GetClientRect(hwnd, &rc);
 148     else
 149         CopyRect(&rc, rect);
 150     if (clipRect == NULL)
 151         GetClientRect(hwnd, &cliprc);
 152     else
 153         CopyRect(&cliprc, clipRect);
 154
 155     ScrollDC(hdc, dx, dy, &rc, &cliprc, hrgnUpdate, rcUpdate);
 156
 157     if (flags | SW_INVALIDATE)
 158     {
 159         RedrawWindow(hwnd, NULL, hrgnUpdate,
 160                      RDW_INVALIDATE | ((flags & SW_ERASE) ? RDW_ERASENOW : 0));
 161     }
 162
 163     ReleaseDC(hwnd, hdc);
 164     return RgnType;
 165 }