programs/taskmgr/proclist.c

   1 /*
   2  *  ReactOS Task Manager
   3  *
   4  *  proclist.c
   5  *
   6  *  Copyright (C) 1999 - 2001  Brian Palmer  <brianp@reactos.org>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  21  */
  22
  23 #define WIN32_LEAN_AND_MEAN    /* Exclude rarely-used stuff from Windows headers */
  24 #include <windows.h>
  25 #include <commctrl.h>
  26 #include <stdlib.h>
  27 #include <memory.h>
  28 #include <tchar.h>
  29 #include <stdio.h>
  30 #include <winnt.h>
  31
  32 #include "taskmgr.h"
  33 #include "perfdata.h"
  34
  35
  36 WNDPROC                OldProcessListWndProc;
  37
  38
  39 LRESULT CALLBACK ProcessListWndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
  40 {
  41     HBRUSH    hbrBackground;
  42     int     count;
  43     RECT    rcItem;
  44     RECT    rcClip;
  45     HDC        hDC;
  46     int        DcSave;
  47
  48     switch (message)
  49     {
  50     case WM_ERASEBKGND:
  51
  52         /*
  53          * The list control produces a nasty flicker
  54          * when the user is resizing the window because
  55          * it erases the background to white, then
  56          * paints the list items over it.
  57          *
  58          * We will clip the drawing so that it only
  59          * erases the parts of the list control that
  60          * show only the background.
  61          */
  62
  63         /*
  64          * Get the device context and save it's state
  65          * to be restored after we're done
  66          */
  67         hDC = (HDC) wParam;
  68         DcSave = SaveDC(hDC);
  69
  70         /*
  71          * Get the background brush
  72          */
  73         hbrBackground = (HBRUSH) GetClassLongPtrW(hWnd, GCLP_HBRBACKGROUND);
  74
  75         /*
  76          * Calculate the clip rect by getting the RECT
  77          * of the first and last items and adding them up.
  78          *
  79          * We also have to get the item's icon RECT and
  80          * subtract it from our clip rect because we don't
  81          * use icons in this list control.
  82          */
  83         rcClip.left = LVIR_BOUNDS;
  84         SendMessageW(hWnd, LVM_GETITEMRECT, 0, (LPARAM) &rcClip);
  85         rcItem.left = LVIR_BOUNDS;
  86         count = SendMessageW(hWnd, LVM_GETITEMCOUNT, 0, 0);
  87         SendMessageW(hWnd, LVM_GETITEMRECT, count - 1, (LPARAM) &rcItem);
  88
  89         rcClip.bottom = rcItem.bottom;
  90         rcItem.left = LVIR_ICON;
  91         SendMessageW(hWnd, LVM_GETITEMRECT, 0, (LPARAM) &rcItem);
  92         rcClip.left = rcItem.right;
  93
  94         /*
  95          * Now exclude the clip rect
  96          */
  97         ExcludeClipRect(hDC, rcClip.left, rcClip.top, rcClip.right, rcClip.bottom);
  98
  99         /*
 100          * Now erase the background
 101          *
 102          *
 103          * FIXME: Should I erase it myself or
 104          * pass down the updated HDC and let
 105          * the default handler do it?
 106          */
 107         GetClientRect(hWnd, &rcItem);
 108         FillRect(hDC, &rcItem, hbrBackground);
 109
 110         /*
 111          * Now restore the DC state that we
 112          * saved earlier
 113          */
 114         RestoreDC(hDC, DcSave);
 115
 116         return TRUE;
 117     }
 118
 119     /*
 120      * We pass on all messages except WM_ERASEBKGND
 121      */
 122     return CallWindowProcW(OldProcessListWndProc, hWnd, message, wParam, lParam);
 123 }