reactos/sdk/lib/conutils/pager.c

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS Console Utilities Library
   4  * FILE:            sdk/lib/conutils/pager.c
   5  * PURPOSE:         Console/terminal paging functionality.
   6  * PROGRAMMERS:     - Hermes Belusca-Maito (for the library);
   7  *                  - All programmers who wrote the different console applications
   8  *                    from which I took those functions and improved them.
   9  */
  10
  11 /* FIXME: Temporary HACK before we cleanly support UNICODE functions */
  12 #define UNICODE
  13 #define _UNICODE
  14
  15 #include <stdlib.h> // limits.h // For MB_LEN_MAX
  16
  17 #include <windef.h>
  18 #include <winbase.h>
  19 // #include <winnls.h>
  20 #include <wincon.h>  // Console APIs (only if kernel32 support included)
  21 #include <strsafe.h>
  22
  23 #include "conutils.h"
  24 #include "stream.h"
  25 #include "screen.h"
  26 #include "pager.h"
  27
  28 // Temporary HACK
  29 #define CON_STREAM_WRITE    ConStreamWrite
  30
  31
  32
  33 /* Returns TRUE when all the text is displayed, and FALSE if display is stopped */
  34 BOOL
  35 ConWritePaging(
  36     IN PCON_PAGER Pager,
  37     IN PAGE_PROMPT PagePrompt,
  38     IN BOOL StartPaging,
  39     IN PTCHAR szStr,
  40     IN DWORD len)
  41 {
  42     CONSOLE_SCREEN_BUFFER_INFO csbi;
  43
  44     /* Used to see how big the screen is */
  45     DWORD ScreenLines = 0;
  46
  47     /* Chars since start of line */
  48     DWORD CharSL;
  49
  50     DWORD from = 0, i = 0;
  51
  52     /* Parameters validation */
  53     if (!Pager)
  54         return FALSE;
  55
  56     /* Reset LineCount and return if no string has been given */
  57     if (StartPaging == TRUE)
  58         Pager->LineCount = 0;
  59     if (szStr == NULL)
  60         return TRUE;
  61
  62     /* Get the size of the visual screen that can be printed to */
  63     if (!ConGetScreenInfo(Pager->Screen, &csbi))
  64     {
  65         /* We assume it's a file handle */
  66         CON_STREAM_WRITE(Pager->Screen->Stream, szStr, len);
  67         return TRUE;
  68     }
  69
  70     /*
  71      * Get the number of lines currently displayed on screen, minus 1
  72      * to account for the "press any key..." prompt from PagePrompt().
  73      */
  74     ScreenLines = (csbi.srWindow.Bottom - csbi.srWindow.Top);
  75     CharSL = csbi.dwCursorPosition.X;
  76
  77     /* Make sure the user doesn't have the screen too small */
  78     if (ScreenLines < 4)
  79     {
  80         CON_STREAM_WRITE(Pager->Screen->Stream, szStr, len);
  81         return TRUE;
  82     }
  83
  84     while (i < len)
  85     {
  86         /* Search until the end of a line is reached */
  87         if (szStr[i++] != TEXT('\n') && ++CharSL < csbi.dwSize.X)
  88             continue;
  89
  90         Pager->LineCount++;
  91         CharSL = 0;
  92
  93         if (Pager->LineCount >= ScreenLines)
  94         {
  95             CON_STREAM_WRITE(Pager->Screen->Stream, &szStr[from], i-from);
  96             from = i;
  97
  98             /* Prompt the user; give him some values for statistics */
  99             // FIXME TODO: The prompt proc can also take ScreenLines ??
 100             if (!PagePrompt(Pager, from, len))
 101                 return FALSE;
 102
 103             // TODO: Recalculate 'ScreenLines' in case the user redimensions
 104             // the window during the prompt.
 105
 106             /* Reset the number of lines being printed */
 107             Pager->LineCount = 0;
 108         }
 109     }
 110     if (i > from)
 111         CON_STREAM_WRITE(Pager->Screen->Stream, &szStr[from], i-from);
 112
 113     return TRUE;
 114 }
 115
 116 BOOL
 117 ConPutsPaging(
 118     IN PCON_PAGER Pager,
 119     IN PAGE_PROMPT PagePrompt,
 120     IN BOOL StartPaging,
 121     IN LPTSTR szStr)
 122 {
 123     DWORD len;
 124
 125     /* Return if no string has been given */
 126     if (szStr == NULL)
 127         return TRUE;
 128
 129     len = wcslen(szStr);
 130     return ConWritePaging(Pager, PagePrompt, StartPaging, szStr, len);
 131 }
 132
 133 BOOL
 134 ConResPaging(
 135     IN PCON_PAGER Pager,
 136     IN PAGE_PROMPT PagePrompt,
 137     IN BOOL StartPaging,
 138     IN UINT uID)
 139 {
 140     INT Len;
 141     PWCHAR szStr = NULL;
 142
 143     Len = K32LoadStringW(GetModuleHandleW(NULL), uID, (PWSTR)&szStr, 0);
 144     if (szStr && Len)
 145         return ConWritePaging(Pager, PagePrompt, StartPaging, szStr, Len);
 146     else
 147         return TRUE;
 148 }