the memory buffer (TokenPtr) for the length of the token, into the variable TokenStr.
ScanForRtf just checks through the resultant TokenStr to ensure it doesn''''t have any funny characters that the RichEdit would confuse as RTF commands. If it finds any, it escapes them out.
SetRTF looks at the FTokenState to populate two global variables Prefix and Postfix with the appropriate RTF codes to give the token the right Color,Font,Boldness.
WriteToBuffer than simply puts the TokenStr with the Prefix and Postfix around it into the output buffer, and the loop then continues on.
Back to the topic: Syntax Highlighting (on-the-fly)
No source code is necessarily 100% applicable to your needs. I was fortunate in that most of the parser applied to my 4GL command syntax (e.g Strings were strings, Numbers were numbers, similar Keywords). As well YourPasEditor had implemented most of the basic accessory tasks such as Printing, Find, Find and Replace, Multi-File editing. It was just a matter of adding in the extras I was after.
PROBLEM #1 - No colours or fonts
One task the Parser didn''''t fully implement was Colors or Different Fonts, or even fonts sizes. The reason for this (after some trial and error) was that the SetRTF procedure new nothing about how to do this. It only used the information in regards [Bold], [Italics] and [Underline] stored in the Win95 Registry for the Delphi Editors Settings to determine how to highlight each token. As for fonts - well I hadn''''t realised that the Delphi Editor actually uses only one Font and Fontsize for all the different tokens - so that wasn''''t Pas2Rtf fault. I was just being greedy.
Luckily the comments in Pas2Rtt.pas told me what the other values in the Registry coded for, especially where the important foreground color was stored. This meant some changes to:
1. procedure SetDelphiRTF(S: String; aTokenState: TTokenState);
Add after the try;
Font.Color := StrToInt(Ed_List[0]);
2. procedure TPasConversion.SetPreAndPosFix
Add after FPreFix[aTokenState] = '''''''';
FPreFixList[aTokenState] := ColorToRtf(aFont.Color);
The ColorToRtf codes is already present, but hadn''''t been used for some reasone. If you try it out you''''ll understand why :-). You get absolutely no change except lots of '''';'''' in the wrong place.Change the '''';'''' to ''''(space)'''' in ColorToRtf(), and you get rid of the '''';'''' appearing in the RichEdit control, but no Colors anyway.
My first thought was that the value in Ed_List[0] didn''''t convert to a proper Font.Color. The easiest way to test this was to hard code Font.Color := clGreen; and see what happens. Again no luck. The format was consistent with the RTF codes I could see in the RTF header. What the $#%#$%# was wrong with it ?
It was about then that I realised I needed a crash course in RTF document structure. For this I rushed off to www.microsoft.com (please forgive me) and found a reference on RTF. After an hour of reading a Microsoft Technical Document I was even more confused. Oh well - this meant it was time to get dirty. Time to get down to real programmer stuff. Time to "cheat".
What did I do? I went into WordPad (which is just a glorified RichEdit version 2.0 on steroids) and saved various files into RTF format. I then opened them in NotePad so I could see the RTF codes and compare what happened in each case: what codes were produced depending on what I did, or didn''''t do. A similar sort of technique was used back in the 1980s to decipher the first Paradox database format :-) Sorry Borland.
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