Custom controls and arrays..

[Borje Hagsten]

I have a bit of a problem here. For a custom Edit control, I would
like to use an array of dynamic strings, instead of a memory block
with fixed length lines of strings.

The last one is fairly easy - allocate memory, store handle, unlock,
resize, lock, etc. I guess the current PB editor is built that way,
hence the limit of 256 character per line.

But for array of dynamic strings? Resizing a memory block for each
and every change, then extracting the strings to be shown slows down
everything too much. Even allocating some extra memory to avoid too
much resizing doesn't help, since it's extracting the lines of text
to be shown that makes it a bit too slow for my taste.

So, my question is: Is there a fairly easy way of making an array
of dynamic strings "Global" for one unique instance only ? Is this
where "Threads" comes into the picture? Never had to deal with that
area before, so I know very little about it, but before I start
reading up on it, I thought I'd ask, in case someone knows of a
better and/or easier way of doing it..


------------------

[Jules Marchildon]

[This message has been edited by Jules Marchildon (edited January 11, 2001).]

[Tom Hanlin]

The line length limit for PowerBASIC is related to internal compiler buffers, not the IDE per se, which does use dynamic strings.

Dynamic strings can be very slow in Windows. There are a few tricks that can make a dramatic speed difference to your programs. It's worth going out of your way to replace techniques that involve multiple string concatenation or trimming with other methods. Using a BYTE PTR to access string data can also make a drastic difference.

Optimization of string handling is a moderately involved topic. I'll see if I can write something up when I get the chance.

------------------
Tom Hanlin
PowerBASIC Staff

[Paul Noble]

FWIW, there was a very good article 'Play VB's Strings' by Francesco Balena in the April 1998 edition of VBPJ. Some of it is of course VB-specific, but there's good stuff in there for us too, as it is fundamentally about dynamic strings and how to get performance out of them.

The article appears to have been archived onto Francesco's own web site at http://www.vb2themax.com/ArticleBank...ID=ArticleBank (scroll down).

Regards -

Paul



[This message has been edited by Paul Noble (edited January 10, 2001).]

[Borje Hagsten]

Thanks Jules. I once downloaded the free CodeMax editor code and
have looked at it. Maybe that is the one you have too. While it's
fairly easy to follow, it doesn't work the way I would like to use,
but maybe I will have to give in and use the same approach myself.

Tom, I have tried using byte pointers and it actually was a bit
slower in many situations. I may have started in the wrong end
with this project, since I've built it around simple array with
dynamic strings. Seems like I need to build a memory management
"engine" for home-rolled array of dynamic strings here. Could be fun.

As it is, it works fine in one instance, but not in MDI projects,
etc, which is a must for an editor control. I'll solve it. It's a
too good project to be left behind in some drawer, so even if my
time is limited, I'll find a way some day. The goal is to be able
to kiss Rich Edit goodbye for good..

Paul, thanks for the tip. I'll have a look at it.


The code is not presentable in any way right now, but I have uploaded
a small test program to http://www.tolken99.com/ed32edit.exe ,
in case you want to see what will come.

The sample shows an editor control in the makes, you could say. As
it is, it has syntax coloring and right now, automatic UCASE for
PB code. Light yellow background is just a test of %WM_CTLCOLOREDIT.
It's quite fast, even before optimization.

F2 sets bookmarks in marging. Ctrl+F3 and Ctrl+Shift+F3 moves between
bookmarks. Will use other bookmarks in finished editor. Click in
margin selects full line. Doubleclick in marging selects full SUB
or FUNCTION, if line is within one of those.

Since it's a raw copy, you only have three buttons to play around
with, "Open..", for opening files, "UCASE" and "MCASE" test code
for selected text, plus a right click menu with some neat test
stuff in, like show/hide non-printable characters, turn syntax
coloring on/off, add line numbers, etc.

Oh yes, I have started working on a HTML syntax color parser too,
so you can test to open up a HTML file with it, just to see.

Left to do is solving the issue above, multilevel Undo/Redo, Syntax
color parser for C++ code, or at least one that handles resource files
properly, plus clearing out tons of test code and add some other
things I personally like to see in an editor. Will take some time,
but I promise I will share the resulting code, once it's ready..


------------------

[Jules Marchildon]

Borje;

Your test fixture is lookin' Good!!!!

Regards,
Jules


[This message has been edited by Jules Marchildon (edited January 11, 2001).]