windows/scroll.c

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