From d81443f7f44756733bbb8e12fdb906ec441ef106 Mon Sep 17 00:00:00 2001
From: mysticbbs <mysticbbs@gmail.com>
Date: Thu, 24 Jan 2013 15:44:47 -0500
Subject: [PATCH] Initial import scrollback class extends generic tOutput layer

---
 mdl/m_output_scrollback.pas | 116 ++++++++++++++++++++++++++++++++++++
 1 file changed, 116 insertions(+)
 create mode 100644 mdl/m_output_scrollback.pas

diff --git a/mdl/m_output_scrollback.pas b/mdl/m_output_scrollback.pas
new file mode 100644
index 0000000..0133c01
--- /dev/null
+++ b/mdl/m_output_scrollback.pas
@@ -0,0 +1,116 @@
+Unit m_Output_ScrollBack;
+
+{$I M_OPS.PAS}
+
+Interface
+
+Uses
+  m_Types,
+  m_Output;
+
+Const
+  MaxScrollBufferSize = 1000;
+
+Type
+  TConsoleScrollback = Class(TOutput)
+    ScrollBuf : Array[1..MaxScrollBufferSize] of TConsoleLineRec;
+    ScrollPos : SmallInt;
+    Capture   : Boolean;
+
+    Constructor Create (A: Boolean);
+    Destructor  Destroy; Override;
+
+    Procedure   ClearBuffer;
+    Procedure   AddLine     (Line: Word);
+    Function    IsBlankLine (Line: Word) : Boolean;
+    Procedure   ClearScreen; Override;
+    Procedure   ScrollWindow; Override;
+  End;
+
+Implementation
+
+Constructor TConsoleScrollback.Create (A: Boolean);
+Begin
+  Inherited Create(A);
+
+  ClearBuffer;
+
+  Capture := False;
+End;
+
+Destructor TConsoleScrollback.Destroy;
+Begin
+  Inherited Destroy;
+End;
+
+Procedure TConsoleScrollback.ClearBuffer;
+Var
+  Count1 : LongInt;
+  Count2 : LongInt;
+Begin
+  ScrollPos := 0;
+
+  For Count1 := 1 to MaxScrollBufferSize Do
+    For Count2 := 1 to 80 Do Begin
+      ScrollBuf[Count1][Count2].Attributes  := 7;
+      ScrollBuf[Count1][Count2].UnicodeChar := ' ';
+    End;
+End;
+
+Procedure TConsoleScrollback.AddLine (Line: Word);
+Begin
+  If ScrollPos = MaxScrollBufferSize Then Begin
+    Move(ScrollBuf[2][1], ScrollBuf[1][1], SizeOf(TConsoleLineRec) * (MaxScrollBufferSize - 1));
+    Dec(ScrollPos);
+  End;
+
+  Inc  (ScrollPos);
+  Move (Buffer[Line][1], ScrollBuf[ScrollPos][1], SizeOf(TConsoleLineRec));
+End;
+
+Function TConsoleScrollback.IsBlankLine (Line: Word) : Boolean;
+Var
+  Count : LongInt;
+Begin
+  Result := True;
+
+  For Count := 1 to 80 Do
+    If (Buffer[Line][Count].UnicodeChar <> #0) and ((Buffer[Line][Count].UnicodeChar <> ' ') and (Buffer[Line][Count].Attributes <> 7)) Then Begin
+      Result := False;
+      Exit;
+    End;
+End;
+
+Procedure TConsoleScrollback.ClearScreen;
+Var
+  Line  : LongInt;
+  Count : LongInt;
+Begin
+  If Capture Then Begin
+    {$IFDEF WIN32}
+      Line := Window.Bottom + 1;
+    {$ELSE}
+      Line := FWinBot;
+    {$ENDIF}
+
+    While Line > 0 Do Begin
+      If Not IsBlankLine(Line) Then Break;
+      Dec(Line);
+    End;
+
+    If Line <> 0 Then
+      For Count := 1 to Line Do
+        AddLine(Count);
+  End;
+
+  Inherited ClearScreen;
+End;
+
+Procedure TConsoleScrollBack.ScrollWindow;
+Begin
+  If Capture Then AddLine(1);
+
+  Inherited ScrollWindow;
+End;
+
+End.