riched20: rich edit control in Wine

[Retrieved on 24 Jan 2009 from www.thomaskho.com/silenceisdefeat/seas/wine. Also previously online at www.seas.ucla.edu/~kho/wine.]

Maintained by: Thomas Kho <tkho@ucla.edu>

Last Updated: 20 June 2006

This page contains notes on the rich edit control in riched20.dll and lists features that would be nice to have implemented.

Table of Contents

• Introduction
• Unimplemented messages
• Patches
• riched20 internals

Introduction

The following links may help in getting started:

• Dan Kegel's Software Engineering with Wine
• dlls/riched20/editor.c contains the message handler RichEditANSIWndProc that allows interaction with the rich edit control.
• This patch for Wine bug PR3440 shows how to implement two features. Understanding this patch (and others like it) is probably the first step
• The Wine Cross Reference may be useful to quickly find the definition and uses of names.
• Wine Coding Hints for conformance tests
• Writing Conformance tests - part of Wine Developer's Guide
• #winehackers on irc.freenode.net

Course Links:

• Winter 2006 - CS 130 Wine Wiki
• Winter 2005 - CS 130 Wine Wiki

Unimplemented messages

The following is a list of unimplemented messages/features that are sent/used by actual programs. See rich edit controls on MSDN for specifications of most messages [try a search for those not listed on this page]. Also, see dlls/riched20/editor.c for the implementation status of all messages.

Message	WineHQ Hits	Comments
EM_AUTOURLDETECT	4	provides automatic url detection [also EM_GETAUTOURLDETECT]
EM_DISPLAYBAND	1	formatting for output device, depends on EM_FORMATRANGE
EM_EXLIMITTEXT	15	specify max characters for a rich edit control [also EM_GETLIMITTEXT, EM_LIMITTEXT]
EM_FINDTEXT	?
EM_FORMATRANGE	3	formatting for output device
EM_GETLANGOPTIONS	1	[also EM_SETLANGOPTIONS]
EM_GETLINE	2
EM_HIDESELECTION	1
EM_SCROLL	1 (google earth)	scroll rich edit control
EM_SCROLLCARET	1	scroll so that the caret is visible - I am implementing this as an example for CS 130 students
EM_SETOLECALLBACK	1	Implemented 20060131
EM_SETOPTIONS	1
EM_SETTARGETDEVICE	1
EM_SETTEXTMODE	2
EM_SETUNDOLIMIT	2
WM_SETFONT	lots
WM_STYLECHANGING	lots
WM_STYLECHANGED	lots

bold text means that the control is being/has been implemented by a student in CS 130

Patches

A list of patches is below. You may have to run `autoconf` to update the configure script.

Patches I'm trying to get committed

• 20060215 - EM_SCROLLCARET and EM_GETSCROLLPOS - implementation + conformance test

Other current patches

• 20060131 - conftest - big patch...what I work off of

Committed patches

• 20060214 - EM_FINDTEXT - additional conformance tests
• 20060203 - EM_FINDTEXT - riched20 conformance test + bug 4479 patch

Old patches

• 20060209 - EM_SCROLLCARET - implementation
• 20060209 - EM_FINDTEXT conformance test
• 20060131 - EM_SCROLLCARET implementation - applies onto previous (see accompanying note)
• 20060131 - EM_SCROLLCARET conformance test - applies onto previous (see accompanying note)
• 20060131 - conftest - submitted to wine-patches
• 20060126 - update to Jan 24 patch - added test for EM_FINDTEXT corner case noted in bug 4144
• 20060124 - patch to add conformance test of only find messages - aim is to get this patch into Wine ASAP
• 20060119 - patch to add conformance test

riched20 internals

This is very much a work in progress, and must be taken with a grain of salt. As I implement EM_SCROLLCARET, my goal is to document the internal workings of riched20 so that anyone else adding features can hit the ground running.

The ME_TextEditor structure in editstr.h defines the edit box. Members are aptly named, including:

• nScrollPosY - current vertical scroll position
• bRedraw - flag to control programatic redraws
• editor - a pointer to an ME_TextBuffer that stores the rich text contents.

  The ME_TextBuffer contains a pointer into a doubly-linked list of ME_DisplayItem. An ME_DisplayItem has a member that is one of [via a union] run, row, paragraph, ustyle. The apparent relationship is as follows: a paragraph consists of one or more rows. Each row consists of one or more runs of text, with the text in each run having the same formatting.

  This file shows the internal representation for some sample text. You can view the structure of the ME_TextBuffer with ME_DumpDocument() after setting your environment with "WINE_DEBUG=trace+richedit_lists".