[hbelusca] 72955: [CMD] - Improve the screen pager so that it looks a bit more like MORE's one: display full screen pages, where only the last line contains the "press any key..." prompt, and erase...

Author: hbelusca
Date: Mon Oct 10 19:15:07 2016
New Revision: 72955
URL: http://svn.reactos.org/svn/reactos?rev=72955&view=rev
Log:
[CMD]
- Improve the screen pager so that it looks a bit more like MORE's one: display full
screen pages, where only the last line contains the "press any key..." prompt,
and erase this prompt when a key is pressed and before displaying the other screen page.
- GetScreenSize parameters are pointers (so use NULL instead of 0);
- Use ARRAYSIZE instead of hardcoding buffer number of elements;
- Simplify PrintInfoLine() (use read-only resource string buffer returned by LoadString
instead of a temporary buffer, since we are just interested in the counted string).
Modified:
    trunk/reactos/base/shell/cmd/console.c
    trunk/reactos/base/shell/cmd/dir.c
    trunk/reactos/base/shell/cmd/filecomp.c
    trunk/reactos/base/shell/cmd/misc.c
    trunk/reactos/base/shell/cmd/prompt.c
Modified: trunk/reactos/base/shell/cmd/console.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/base/shell/cmd/console.c?r…
==============================================================================
--- trunk/reactos/base/shell/cmd/console.c      [iso-8859-1] (original)
+++ trunk/reactos/base/shell/cmd/console.c      [iso-8859-1] Mon Oct 10 19:15:07 2016
@@ -303,13 +303,13 @@
     DWORD dwWritten;
     HANDLE hOutput = GetStdHandle(nStdHandle);
-    /* used to count number of lines since last pause */
+    /* Used to count number of lines since last pause */
     static int LineCount = 0;
-    /* used to see how big the screen is */
+    /* Used to see how big the screen is */
     int ScreenLines = 0;
-    /* chars since start of line */
+    /* Chars since start of line */
     int CharSL;
     int from = 0, i = 0;
@@ -317,22 +317,26 @@
     if (NewPage == TRUE)
         LineCount = 0;
-    /* rest LineCount and return if no string have been given */
+    /* Reset LineCount and return if no string has been given */
     if (szFormat == NULL)
         return 0;
-    /* Get the size of the visual screen that can be printed too */
+    /* Get the size of the visual screen that can be printed to */
     if (!IsConsoleHandle(hOutput) || !GetConsoleScreenBufferInfo(hOutput, &csbi))
     {
         /* We assume it's a file handle */
         ConPrintf(szFormat, arg_ptr, nStdHandle);
         return 0;
     }
-    /* Subtract 2 to account for "press any key..." and for the blank line at
the end of PagePrompt() */
-    ScreenLines = (csbi.srWindow.Bottom  - csbi.srWindow.Top) - 4;
+
+    /*
+     * Get the number of lines currently displayed on screen, minus 1
+     * to account for the "press any key..." prompt from PagePrompt().
+     */
+    ScreenLines = (csbi.srWindow.Bottom - csbi.srWindow.Top);
     CharSL = csbi.dwCursorPosition.X;
-    /* Make sure they didn't make the screen to small */
+    /* Make sure the user doesn't have the screen too small */
     if (ScreenLines < 4)
     {
         ConPrintf(szFormat, arg_ptr, nStdHandle);
@@ -355,10 +359,15 @@
             WriteConsole(hOutput, &szOut[from], i-from, &dwWritten, NULL);
             from = i;
+            /* Prompt the user */
             if (PagePrompt() != PROMPT_YES)
             {
                 return 1;
             }
+
+            // TODO: Recalculate 'ScreenLines' in case the user redimensions
+            // the window during the prompt.
+
             /* Reset the number of lines being printed */
             LineCount = 0;
         }
Modified: trunk/reactos/base/shell/cmd/dir.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/base/shell/cmd/dir.c?rev=7…
==============================================================================
--- trunk/reactos/base/shell/cmd/dir.c  [iso-8859-1] (original)
+++ trunk/reactos/base/shell/cmd/dir.c  [iso-8859-1] Mon Oct 10 19:15:07 2016
@@ -970,7 +970,7 @@
     }
     /* Count the highest number of columns */
-    GetScreenSize(&iScreenWidth, 0);
+    GetScreenSize(&iScreenWidth, NULL);
     iColumns = (USHORT)(iScreenWidth / iLongestName);
     /* Check if there is enough space for spaces between names */
Modified: trunk/reactos/base/shell/cmd/filecomp.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/base/shell/cmd/filecomp.c?…
==============================================================================
--- trunk/reactos/base/shell/cmd/filecomp.c     [iso-8859-1] (original)
+++ trunk/reactos/base/shell/cmd/filecomp.c     [iso-8859-1] Mon Oct 10 19:15:07 2016
@@ -290,7 +290,7 @@
         hFile = FindFirstFile (path, &file);
         /* Count the highest number of columns */
-        GetScreenSize(&screenwidth, 0);
+        GetScreenSize(&screenwidth, NULL);
         /* For counting columns of output */
         count = 0;
Modified: trunk/reactos/base/shell/cmd/misc.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/base/shell/cmd/misc.c?rev=…
==============================================================================
--- trunk/reactos/base/shell/cmd/misc.c [iso-8859-1] (original)
+++ trunk/reactos/base/shell/cmd/misc.c [iso-8859-1] Mon Oct 10 19:15:07 2016
@@ -148,7 +148,7 @@
             if (!bCtrlBreak)
                 return FALSE;
-            LoadString(CMD_ModuleHandle, STRING_COPY_OPTION, options, 4);
+            LoadString(CMD_ModuleHandle, STRING_COPY_OPTION, options,
ARRAYSIZE(options));
             /* we need to be sure the string arrives on the screen! */
             do
@@ -536,6 +536,7 @@
 INT PagePrompt(VOID)
 {
+    SHORT iScreenWidth, iCursorY;
     INPUT_RECORD ir;
     ConOutResPuts(STRING_MISC_HELP1);
@@ -554,10 +555,24 @@
     AddBreakHandler();
     ConInEnable();
+    /*
+     * Get the screen width, erase the full line where the cursor is,
+     * and move the cursor back to the beginning of the line.
+     */
+    GetScreenSize(&iScreenWidth, NULL);
+    iCursorY = GetCursorY();
+    SetCursorXY(0, iCursorY);
+    while (iScreenWidth-- > 0) // Or call FillConsoleOutputCharacter ?
+        ConOutChar(_T(' '));
+    SetCursorXY(0, iCursorY);
+
     if ((ir.Event.KeyEvent.wVirtualKeyCode == VK_ESCAPE) ||
         ((ir.Event.KeyEvent.wVirtualKeyCode == _T('C')) &&
          (ir.Event.KeyEvent.dwControlKeyState & (LEFT_CTRL_PRESSED |
RIGHT_CTRL_PRESSED))))
     {
+        /* We break, output a newline */
+        ConOutChar(_T('\n'));
+
         bCtrlBreak = TRUE;
         return PROMPT_BREAK;
     }
Modified: trunk/reactos/base/shell/cmd/prompt.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/base/shell/cmd/prompt.c?re…
==============================================================================
--- trunk/reactos/base/shell/cmd/prompt.c       [iso-8859-1] (original)
+++ trunk/reactos/base/shell/cmd/prompt.c       [iso-8859-1] Mon Oct 10 19:15:07 2016
@@ -78,14 +78,16 @@
     COORD coPos;
     DWORD dwWritten;
-    TCHAR szInfoLine[80 + 1]; // The info line is 80 characters long (without NULL
character)
+    PTSTR pszInfoLine = NULL;
     INT iInfoLineLen;
     /* Return directly if the output handle is not a console handle */
     if (!GetConsoleScreenBufferInfo(hOutput, &csbi))
         return;
-    iInfoLineLen = LoadString(CMD_ModuleHandle, STRING_CMD_INFOLINE, szInfoLine,
ARRAYSIZE(szInfoLine));
+    iInfoLineLen = LoadString(CMD_ModuleHandle, STRING_CMD_INFOLINE,
(PTSTR)&pszInfoLine, 0);
+    if (!pszInfoLine || iInfoLineLen == 0)
+        return;
     /* Display the localized information line */
     coPos.X = 0;
@@ -97,7 +99,7 @@
                                csbi.dwSize.X,
                                coPos, &dwWritten);
-    WriteConsoleOutputCharacter(hOutput, szInfoLine, iInfoLineLen,
+    WriteConsoleOutputCharacter(hOutput, pszInfoLine, iInfoLineLen,
                                 coPos, &dwWritten);
 }