C / C++ / MFC

Re: Internet Explorer List Control

3-Jun-02 9:39

Check PJ Naughter's CTreeOptionsCtrl.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

Le centriste3-Jun-02 12:41

Le centriste

3-Jun-02 12:41

Tx exactly what I needed.

Michel

It is a lovely language, but it takes a very long time to say anything in it, because we do not say anything in it, unless it is worth taking a very long time to say, and to listen to.

- TreeBeard

Backup - Registry & File :: MFC

valikac3-Jun-02 8:59

valikac

3-Jun-02 8:59

Hi.

I am in the process of implementing a feature for a program that involves saving and restoring expendable data. For example, let say the program organizes a list of names. I would like to save the names when the program closes and load the names when the program starts.

What is the maximum data size that a program can save and restore via registry?

I find saving and restoring data via registry is quicker and easier than saving the data to a file and reading the data back into memory.

Thanks,
Kuphryn

Joaquín M López Muñoz3-Jun-02 9:18

3-Jun-02 9:18

There's no predefined limit as to how much data you can store in the registry. If your list of names is not huge, I guess the registry is a fine place to save it --plus you obtain added benefits like per-user configuration (if you select a key under HKEY_CURRENT_USR.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

valikac3-Jun-02 11:48

valikac

3-Jun-02 11:48

Okay. Thanks.

Kuphryn

Ed Gadziemski3-Jun-02 11:57

Ed Gadziemski

3-Jun-02 11:57

You can run out of allocated registry space on Windows NT and get error messages. That might be disconcerting to users.

Ed Gadziemski3-Jun-02 11:59

Ed Gadziemski

3-Jun-02 11:59

The registry is non-indexed, so the bigger it gets, the slower it gets. That may be a problem if you plan to save and restore a lot of data.

Solution

valikac3-Jun-02 12:12

valikac

3-Jun-02 12:12

Thanks.

I will implement a separate database file and not use the registry. I think going with a file is safer and more flexible in the long run.

Kuphryn

Plugin Framework?

clintsinger3-Jun-02 7:33

clintsinger

3-Jun-02 7:33

Hi all,

I am having a hard time finding a tutorial of how to make my own plugin framework. The problem I have is as such: I want to open the COM ports on my system and have Point of Sale data flow in (each on it's own thread). From there I want a dll for each POS that can be dynamically loaded to parse the data. I would like to make a generic framework so I can just put in new dll's and then enumerate them so the user can select the appropriate one. The application then uses a function that parses the data into the an expected format to be then inserted into SQL server.

Is there a way to load a class froma DLL? That way I could load a class into it's own address space. I suppose this would help make it thread safe?

Thanks in advance,
Clint

Re: Plugin Framework?

C^hris L^osinger3-Jun-02 7:49

3-Jun-02 7:49

IMO, this is the perfect place for COM. in one of my apps, i have a fairly simple plug-in framework set up where users just drop plug-in DLLs into a specific folder and then choose the ones they want from a list. the whole system is based on COleDispatchDriver (which is essentially a wrapper to a COM object - you tell it which COM object to load and then call methods on the COM object through the wrapper). i've seen articles here that do pretty much the same thing i do.

here's a rough outline of how i do it:

1. the app scans a folder for DLLs

2. based on the name of each DLL it finds, it tries this:

COleDispatchDriver d;
d.CreateDispatch(csDLLName+".MyInterface");

3. if that worked, the DLL is added to the list of useable plugin DLLs

4. the user gets to look at the list and choose the plugin(s) that he wants to use

5. when processing time comes, the app does the same CreateDispatch call for each DLL then calls the appropriate methods on the object.

-c

Cheap oil. It's worth it!

wanna do animation, please help

pnpfriend3-Jun-02 7:19

pnpfriend

3-Jun-02 7:19

hi all, i want to have an animation for my printing program. i want to display an animation while the file is printing.
i was reading about BitBlt but i don't really understand. I dont' want to draw programmatically i want to use my own animation gif file. but how am i suppose to post my gif file on the dialog. for bitmap pics i don't know how to create animation. from what i understood, i have to draw several pic and save with bmp extention. then load it, display it and replace it with next pic right. Smile | :)

to me sound so easy, but don't know what to do.
ok loading, i think i have to do: CBitmap::LoadBitmap("c:\mypic.bmp");
but how to display on certain place like buttons i can place anywhere on the dialog.
so no doubt that i can replace or do any animation since i can't even display one bmp on dialog i want.

do you have idea or any similar project?

Joaquín M López Muñoz3-Jun-02 7:59

3-Jun-02 7:59

Check Olek Bykov's excellent article Add GIF-animation to your MFC and ATL projects with the help of CPictureEx and CPictureExWnd. He provides out-of-the-box GIF animation capabilities.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

C^hris L^osinger3-Jun-02 8:59

3-Jun-02 8:59

yes, and then send $3500 to Unisys for a license to use GIF in your application.

-c

Cheap oil. It's worth it!

Joaquín M López Muñoz3-Jun-02 9:15

3-Jun-02 9:15

It is my understanding that non-profit non-commercial apps can freely use GIF technology, which may suit the guy's needs. I'm sure you already know this, but here's a link stating the fact: Unisys Clarifies Policy Regarding Patent Use in On-Line Service Offerings. The key paragraph reads:

Unisys does not require licensing, or fees to be paid, for non-commercial, non-profit GIF-based applications, including those for use on the on-line services.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

C^hris L^osinger3-Jun-02 10:55

3-Jun-02 10:55

from the Unisys LZW website:

In all cases, a written license agreement or statement signed by an authorized Unisys representative is required from Unisys for all use, sale or distribution of any software (including so-called "freeware") and/or hardware providing LZW conversion capability (for example, downloaded software used for creating/displaying GIF images). In certain cases, no license fees may be required, but this needs to be evidenced by a written agreement or written statement signed by an authorized Unisys representative.

-c

Cheap oil. It's worth it!

Joaquín M López Muñoz3-Jun-02 11:08

3-Jun-02 11:08

So it seems there's no escape at all. Chris, beware of your fancy smileys! They could lead you to jail.

Now seriously, why these guys from Unisys insist on this annoying issue? I'm sure the money they've been able to get from it these years is not worth the bad image they have gained.

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo

C^hris L^osinger3-Jun-02 11:10

3-Jun-02 11:10

no, there is no escape: pay the fee or use PNG.

but if i'm not mistaken, the patent expires next june/july.

-c

Cheap oil. It's worth it!

Paul M Watt3-Jun-02 14:56

Paul M Watt

3-Jun-02 14:56

I bought your IS image library a few years ago when it still had GIF support in it. Then I noticed when you removed GIF support, or at least started plastering notices about the license requirements for Unisys.

I was just wondering, did you get in trouble from them, or did you just decide to play it safe and remove GIF support?

Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!

C^hris L^osinger3-Jun-02 15:33

3-Jun-02 15:33

a couple of years ago i noticed that some other toolkit developers (like the guys who make "gd") were starting to get into legal trouble, and some others (like the guys who do JpegLib and LibTiff) were getting out of GIF just in case. so i got out, too. i had the "non-LZW" form of GIF in there for a while, but i pulled it after i learned that Unisys wasn't agreeable to that, either.

-c

Cheap oil. It's worth it!

Paul M Watt3-Jun-02 16:09

Paul M Watt

3-Jun-02 16:09

Are you upset at Unisys? Because it seems that everytime that someone posts a question about GIFs your answers are a little harsh towards Unisys. I could care less either way about Unisys, but that is why I wondered if you had gotten into legal trouble with them.

Build a man a fire, and he will be warm for a day
Light a man on fire, and he will be warm for the rest of his life!

C^hris L^osinger3-Jun-02 16:11

3-Jun-02 16:11

yeah, i'm a little upset at them Smile | :)

but not for anything they did to me personally (yet)

-c

Cheap oil. It's worth it!