Syntax coloring Editor

I wrote really simple color syntax editor based on RICHEDIT control. I spent only one
day on this work (ok one and half), so it’s far from ideal, but the result is suitable for
editing small scripts in VBScript or JScript (this is a part of my work on a script host
application)..

How to use this control:

  1. Insert a RICHEDIT control into a dialog resource. Add a member variable to appropriate
    the CDialog or CFormView derived class and subclass the control in the OnInitDialog
    function. Or create the CTWScriptEdit control then you need it.
  2. To minimize any flickering set the style of the parent window (usually the dialog) to
    WS_CLIPCHILDREN.
  3. Call the Initialize() method of the CTWScriptEdit. (This sets default attributes of the
    text).

How to set parameters of the language:

  • void SetCaseSensitive(BOOL bSensitive);
    Is language case sensitive?
  • void SetChangeCase(BOOL bChange);
    Force case for keywords?
  • void SetSLComment(TCHAR chComment, TCHAR chComment2 = 0);
    Set character(s) for comment (‘\” for VBScsipt, ‘\\’, ‘\\’ for JScript)
  • void SetSLComment(LPCTSTR lpszComment);
    Set keyword for comment ("Rem" for VBScript) must be in the keyword list too
  • void SetStringQuotes(LPCTSTR lpszStrQ);
    Determines string quotation character(s) ("\"")
  • void AddKeywords(LPCTSTR lpszKwd);
    Adds keywords
  • void AddConstants(LPCTSTR lpszKwd);
    Adds constants
  • void SetKeywordColor(COLORREF clr, BOOL bBold);
    Sets color and bold attribute for keywords
  • void SetConstantColor(COLORREF clr, BOOL bBold);
    Sets color and bold attribute for constants
  • void SetCommentColor(COLORREF clr, BOOL bBold);
    Sets color and bold attribute for comment
  • void SetNumberColor(COLORREF clr, BOOL bBold);
    Sets color and bold attribute for numbers
  • void SetStringColor(COLORREF clr, BOOL bBold);
    Sets color and bold attribute for strings

The attached sample project is a simple dialog based application. All described steps
in the source code are outlined by TWSCRIPTEDIT -> <- TWSCRIPTEDIT comment pair.

Comments on the Source Code:

The Interesting code sits in the CTWScriptEdit control (TWScriptEdit.h and
TWScriptEdit.cpp). This control is derived from CRichEditCtrl. The whole miracle occurs in
the EN_PROTECTED and EN_CHANGE notification handlers. All text in the control has the
CFE_PROTECTED flag, so before any change the OnProtected handler is
called. After the change, the OnChange handler is called. This enables us
to determine the affected lines that need reformatting. Real formatting occurs in
FormatTextRange() which parses the range of text and changes necessary attributes by
calling helper functions. The control correctly handles WM_SETTEXT and EM_RELACELSEL, so
it’s possible to change text programmatically.

Known Problems:

The Undo buffer is affected during formatting, so the undo function works incorrectly.

Pasting RTF text from clipboard into the control retains font, size and others
attributes of pasted text. This can be corrected in SetFormatRange() method – just check
and change all attributes.

I am sure that I am better at the C++ language than in English, so my description is
short, but I hope that source code answers all your questions.

Added VBScriptEditor project shows how to implement coloring features in CRichEditView
derivation.

Download source for the CVBScriptEditDlg
and the CVBScriptEdit.

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