release/src/router/apcupsd/src/win32/listview.cpp

   1 /*
   2  * Copyright (C) 2009 Adam Kropelin
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of version 2 of the GNU General
   6  * Public License as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the Free
  15  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  16  * MA 02111-1307, USA.
  17  */
  18
  19 #include <windows.h>
  20 #include <commctrl.h>
  21 #include <limits.h>
  22 #include "listview.h"
  23
  24 ListView::ListView(HWND hwnd, UINT id, int cols) :
  25    _cols(cols)
  26 {
  27    _hwnd = GetDlgItem(hwnd, id);
  28
  29    LVCOLUMN lvc;
  30    lvc.mask = LVCF_SUBITEM;
  31    for (int i = 0; i < cols; i++)
  32    {
  33       lvc.iSubItem = i;
  34       SendMessage(_hwnd, LVM_INSERTCOLUMN, i, (LONG)&lvc);
  35    }
  36 }
  37
  38 int ListView::AppendItem(const char *text)
  39 {
  40    LVITEM lvi;
  41    lvi.mask = LVIF_TEXT;
  42    lvi.iItem = INT_MAX;
  43    lvi.iSubItem = 0;
  44    lvi.pszText = (char*)text;
  45
  46    return SendMessage(_hwnd, LVM_INSERTITEM, 0, (LONG)&lvi);
  47 }
  48
  49 void ListView::UpdateItem(int item, int sub, const char *text)
  50 {
  51    char str[256];
  52
  53    LVITEM lvi;
  54    lvi.mask = LVIF_TEXT;
  55    lvi.iItem = item;
  56    lvi.iSubItem = sub;
  57    lvi.pszText = str;
  58    lvi.cchTextMax = sizeof(str);
  59
  60    int len = SendMessage(_hwnd, LVM_GETITEMTEXT, item, (LONG)&lvi);
  61    if (len == 0 || strcmp(str, text))
  62    {
  63       lvi.pszText = (char*)text;
  64       SendMessage(_hwnd, LVM_SETITEMTEXT, item, (LONG)&lvi);
  65    }
  66 }
  67
  68 int ListView::NumItems()
  69 {
  70    return SendMessage(_hwnd, LVM_GETITEMCOUNT, 0, 0);
  71 }
  72
  73 void ListView::Autosize()
  74 {
  75    for (int i = 0; i < _cols; i++)
  76       SendMessage(_hwnd, LVM_SETCOLUMNWIDTH, i, LVSCW_AUTOSIZE);
  77 }
  78
  79 void ListView::DeleteItem(int item)
  80 {
  81    SendMessage(_hwnd, LVM_DELETEITEM, item, 0);
  82 }
  83
  84 void ListView::UpdateAll(alist<astring>* data[])
  85 {
  86    // The simple way to update the listview would be to remove all items and
  87    // then add them again. However, that causes the control to flicker and the
  88    // scrollbar to reset to the top every time, which makes it pretty much
  89    // unusable. To prevent that, we update the items in-place, adding new ones
  90    // and removing unused ones as necessary. That way the scroll position stays
  91    // put and only the items that change are redrawn.
  92
  93    // Get current item count and prepare to update the listview
  94    int num = NumItems();
  95    int count = 0;
  96
  97    // Add each line to the listview
  98    alist<astring>::const_iterator iter;
  99    for (iter = data[0]->begin(); iter != data[0]->end(); ++iter)
 100    {
 101       // Set main item (leftmost column). This will be an insert if there is no
 102       // existing item at this position or an update if an item already exists.
 103       if (count >= num)
 104          AppendItem(*iter);
 105       else
 106          UpdateItem(count, 0, *iter);
 107
 108       // On to the next item
 109       count++;
 110    }
 111
 112    // Remove any leftover items that are no longer needed.
 113    while (count < num)
 114    {
 115       DeleteItem(count);
 116       num--;
 117    }
 118
 119    // Update remaining columns. This is always an update since main item
 120    // (leftmost column) is guaranteed to exist by code above.
 121    for (int i = 1; i < _cols; i++)
 122    {
 123       int count = 0;
 124       alist<astring>::const_iterator iter;
 125       for (iter = data[i]->begin(); iter != data[i]->end(); ++iter)
 126          UpdateItem(count++, i, *iter);
 127    }
 128
 129    // Autosize listview columns
 130    Autosize();
 131 }