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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  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 <malloc.h>
  28 #include <memory.h>
  29 #include <tchar.h>
  30 #include <stdio.h>
  31 #include <winnt.h>
  32
  33 #include "taskmgr.h"
  34 #include "perfdata.h"
  35
  36
  37 LRESULT CALLBACK    ProcessListWndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);
  38
  39 LONG                OldProcessListWndProc;
  40
  41
  42 LRESULT CALLBACK ProcessListWndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
  43 {
  44     HBRUSH    hbrBackground;
  45     RECT    rcItem;
  46     RECT    rcClip;
  47     HDC        hDC;
  48     int        DcSave;
  49
  50     switch (message)
  51     {
  52     case WM_ERASEBKGND:
  53
  54         /*
  55          * The list control produces a nasty flicker
  56          * when the user is resizing the window because
  57          * it erases the background to white, then
  58          * paints the list items over it.
  59          *
  60          * We will clip the drawing so that it only
  61          * erases the parts of the list control that
  62          * show only the background.
  63          */
  64
  65         /*
  66          * Get the device context and save it's state
  67          * to be restored after we're done
  68          */
  69         hDC = (HDC) wParam;
  70         DcSave = SaveDC(hDC);
  71
  72         /*
  73          * Get the background brush
  74          */
  75         hbrBackground = (HBRUSH) GetClassLong(hWnd, GCL_HBRBACKGROUND);
  76
  77         /*
  78          * Calculate the clip rect by getting the RECT
  79          * of the first and last items and adding them up.
  80          *
  81          * We also have to get the item's icon RECT and
  82          * subtract it from our clip rect because we don't
  83          * use icons in this list control.
  84          */
  85         ListView_GetItemRect(hWnd, 0, &rcClip, LVIR_BOUNDS);
  86         ListView_GetItemRect(hWnd, ListView_GetItemCount(hWnd) - 1, &rcItem, LVIR_BOUNDS);
  87         rcClip.bottom = rcItem.bottom;
  88         ListView_GetItemRect(hWnd, 0, &rcItem, LVIR_ICON);
  89         rcClip.left = rcItem.right;
  90
  91         /*
  92          * Now exclude the clip rect
  93          */
  94         ExcludeClipRect(hDC, rcClip.left, rcClip.top, rcClip.right, rcClip.bottom);
  95
  96         /*
  97          * Now erase the background
  98          *
  99          *
 100          * FIXME: Should I erase it myself or
 101          * pass down the updated HDC and let
 102          * the default handler do it?
 103          */
 104         GetClientRect(hWnd, &rcItem);
 105         FillRect(hDC, &rcItem, hbrBackground);
 106
 107         /*
 108          * Now restore the DC state that we
 109          * saved earlier
 110          */
 111         RestoreDC(hDC, DcSave);
 112
 113         return TRUE;
 114     }
 115
 116     /*
 117      * We pass on all messages except WM_ERASEBKGND
 118      */
 119     return CallWindowProc((WNDPROC)OldProcessListWndProc, hWnd, message, wParam, lParam);
 120 }