sdk/lib/conutils/pager.c

   1 /*
   2  * PROJECT:     ReactOS Console Utilities Library
   3  * LICENSE:     GPL-2.0+ (https://spdx.org/licenses/GPL-2.0+)
   4  * PURPOSE:     Console/terminal paging functionality.
   5  * COPYRIGHT:   Copyright 2017-2018 ReactOS Team
   6  *              Copyright 2017-2018 Hermes Belusca-Maito
   7  */
   8
   9 /**
  10  * @file    pager.c
  11  * @ingroup ConUtils
  12  *
  13  * @brief   Console/terminal paging functionality.
  14  **/
  15
  16 /* FIXME: Temporary HACK before we cleanly support UNICODE functions */
  17 #define UNICODE
  18 #define _UNICODE
  19
  20 #include <windef.h>
  21 #include <winbase.h>
  22 // #include <winnls.h>
  23 #include <wincon.h>  // Console APIs (only if kernel32 support included)
  24 #include <strsafe.h>
  25
  26 #include "conutils.h"
  27 #include "stream.h"
  28 #include "screen.h"
  29 #include "pager.h"
  30
  31 // Temporary HACK
  32 #define CON_STREAM_WRITE    ConStreamWrite
  33
  34
  35
  36 /* Returns TRUE when all the text is displayed, and FALSE if display is stopped */
  37 BOOL
  38 ConWritePaging(
  39     IN PCON_PAGER Pager,
  40     IN PAGE_PROMPT PagePrompt,
  41     IN BOOL StartPaging,
  42     IN PTCHAR szStr,
  43     IN DWORD len)
  44 {
  45     CONSOLE_SCREEN_BUFFER_INFO csbi;
  46
  47     /* Used to see how big the screen is */
  48     DWORD ScreenLines = 0;
  49
  50     /* Chars since start of line */
  51     DWORD CharSL;
  52
  53     DWORD from = 0, i = 0;
  54
  55     /* Parameters validation */
  56     if (!Pager)
  57         return FALSE;
  58
  59     /* Reset LineCount and return if no string has been given */
  60     if (StartPaging == TRUE)
  61         Pager->LineCount = 0;
  62     if (szStr == NULL)
  63         return TRUE;
  64
  65     /* Get the size of the visual screen that can be printed to */
  66     if (!ConGetScreenInfo(Pager->Screen, &csbi))
  67     {
  68         /* We assume it's a file handle */
  69         CON_STREAM_WRITE(Pager->Screen->Stream, szStr, len);
  70         return TRUE;
  71     }
  72
  73     /*
  74      * Get the number of lines currently displayed on screen, minus 1
  75      * to account for the "press any key..." prompt from PagePrompt().
  76      */
  77     ScreenLines = (csbi.srWindow.Bottom - csbi.srWindow.Top);
  78     CharSL = csbi.dwCursorPosition.X;
  79
  80     /* Make sure the user doesn't have the screen too small */
  81     if (ScreenLines < 4)
  82     {
  83         CON_STREAM_WRITE(Pager->Screen->Stream, szStr, len);
  84         return TRUE;
  85     }
  86
  87     while (i < len)
  88     {
  89         /* Search until the end of a line is reached */
  90         if (szStr[i++] != TEXT('\n') && ++CharSL < csbi.dwSize.X)
  91             continue;
  92
  93         Pager->LineCount++;
  94         CharSL = 0;
  95
  96         if (Pager->LineCount >= ScreenLines)
  97         {
  98             CON_STREAM_WRITE(Pager->Screen->Stream, &szStr[from], i-from);
  99             from = i;
 100
 101             /* Prompt the user; give him some values for statistics */
 102             // FIXME TODO: The prompt proc can also take ScreenLines ??
 103             if (!PagePrompt(Pager, from, len))
 104                 return FALSE;
 105
 106             // TODO: Recalculate 'ScreenLines' in case the user redimensions
 107             // the window during the prompt.
 108
 109             /* Reset the number of lines being printed */
 110             Pager->LineCount = 0;
 111         }
 112     }
 113     if (i > from)
 114         CON_STREAM_WRITE(Pager->Screen->Stream, &szStr[from], i-from);
 115
 116     return TRUE;
 117 }
 118
 119 BOOL
 120 ConPutsPaging(
 121     IN PCON_PAGER Pager,
 122     IN PAGE_PROMPT PagePrompt,
 123     IN BOOL StartPaging,
 124     IN LPTSTR szStr)
 125 {
 126     DWORD len;
 127
 128     /* Return if no string has been given */
 129     if (szStr == NULL)
 130         return TRUE;
 131
 132     len = wcslen(szStr);
 133     return ConWritePaging(Pager, PagePrompt, StartPaging, szStr, len);
 134 }
 135
 136 BOOL
 137 ConResPagingEx(
 138     IN PCON_PAGER Pager,
 139     IN PAGE_PROMPT PagePrompt,
 140     IN BOOL StartPaging,
 141     IN HINSTANCE hInstance OPTIONAL,
 142     IN UINT uID)
 143 {
 144     INT Len;
 145     PWCHAR szStr = NULL;
 146
 147     Len = K32LoadStringW(hInstance, uID, (PWSTR)&szStr, 0);
 148     if (szStr && Len)
 149         return ConWritePaging(Pager, PagePrompt, StartPaging, szStr, Len);
 150     else
 151         return TRUE;
 152 }
 153
 154 BOOL
 155 ConResPaging(
 156     IN PCON_PAGER Pager,
 157     IN PAGE_PROMPT PagePrompt,
 158     IN BOOL StartPaging,
 159     IN UINT uID)
 160 {
 161     return ConResPagingEx(Pager, PagePrompt, StartPaging,
 162                           NULL /*GetModuleHandleW(NULL)*/, uID);
 163 }
 164
 165 /* EOF */