Dfm2API Utility

New! Dfm2API Survey!



A Borland VCL Form Converter

This page is dedicated to the Dfm2API utility that has been published in the August 2000 issue of C/C++ Users Journal. It is my desire to extend its capabilities and to fix all the tons of bugs that you’ll find over the time. So I need your feedback: suggestions, improvements, critics and even money!

·          What’s this utility for?
·          Who can benefit from it?
·          What this utility does NOT do?
·          What are the supported controls?
·          How does it work?
·          How can you contribute?
·          Example
·          Code Example
·          History
·          Downloads
·          Status

What’s this utility for?

As you probably know, Borland C++ Builder and Delphi define a resource file format (DFM) that cannot be used in non-VCL applications. Dfm2API is an extendable tool that converts a Borland DFM resource file into a standard RC (resource script) file and a CPP and HPP file. Extendable means that this conversion is not exhaustive, but that you can adapt it at our wish (you can download the code from CUJ site). Because a DFM file contains also a lot of information about controls initializations (e.g. you can specify which strings appears in a combobox without writing code), this utility extracts them and then automatically writes the required code (generally API calls) in a CPP file so that you can use some of the RAD facilities in non-VCL applications too. This utility can also extract DFM resources (i.e. menu, images, etc) from binaries (EXE, DLL). It is then possible to apply this conversion process to binary files, even if the source code is not available!
For example, if you extract the resources from BCB.EXE (C++ Builder 4.0), you can see that there is a Form whose caption text is “Delphi 4.0”. Funny, isn’t it?

Who can benefit from it?

Everybody!!!! Well, that’s not true, but I think that all the people that need a resource script file (both Delphi and C++ Builder users) or that wants to build WinAPI, MFC, or OWL applications could benefit from Dfm2Api. This tool can be also used to port your VCL forms into a Windows CE compatible format.

The main advantages are:

• Dramatically Smaller executable size (more than one order of magnitude!);
• Shorter compile and link time;
• Shorter build time;
• Compatibility with every C/C++ compiler;
• Generated Resources are compatible with MFC, OWL, VWCL, SDK, etc..
• No need for additional DLLs;
• No dependence on any framework release; That means that you don't have to buy/wait for component new releases;

Actually I’m using C++ Builder for prototyping in a lot of situations, and then I use C++ programming to implement all the non-GUI aspects of the application. Then I translate the C++ Builder Forms into standard resources. This reduces considerably both executable size and compile time. I’m planning to also use Delphi for prototyping (which is very very fast) and C++ Builder or Visual C++ as WinAPI development tool. This tool is also useful for all the people that wants to extract bitmaps, menus, etc. from binaries or that wants to spy other programs forms. The extracted DFM files cannot actually be edited by Delphi/C++ Builder, because they need two more files that actually are not (yet) created. This feature, however, will be added in the next releases.

What this utility does NOT do?

It does not convert non-standard windows controls. For example all the Database controls cannot be translated with all their functionalities into Windows controls. It is still possible, anyway, to treat a specific control as another one: for example a THighlyEnhancedAndWonderfulRadioButtonWithFireWorks can be treated as a simple TRadioButton, but the HighlyEnhancedAndWonderfulFireWorks capabilities will be lost. A special configuration file is provided to perform and customize this conversion task. So, it is still possible to convert a TBDEdit into an EditBox, but in that case you’ll lose all the RAD DB facilities and you’ll have to write the code to implement the required DB queries, etc.. It does not (yet) convert TPropertyPages. This functionality will be added in one of the next releases (before 2.0).

It does not (yet) convert events such as OnClick and so on. This functionality will be probably added in release 2.0.

What are the supported controls?

Actually, you can convert the following components into one of the following controls/resources/common dialogs (red one are the latest updates):

Note that not all the properties are converted into resources/ line of code, but I think that the most important ones are treated.

How does it work?

Imagine that you need to design a DialogBox for a MFC, OWL or WinAPI application. What you have to do is simply to design it as a VCL Form, and then convert it with the Dfm2API utility. You’ll obtain an .RC file, that’s (more or less) exactly what you need (a resource script file, defined at the OS level), and a .CPP and .HPP file. The .RC file contains all the statements that are required to generate a .RES file that can be linked to a Win32 module, while the .CPP and .HPP files are responsible to create the proper DIALOGPROC and to initialize the controls that populates the DialogBox (this second steps is done for WinAPI applications). You can see an example here.

How can you contribute?

These are some suggestions:

1) Buy C/C++ Users Journal August 2000 issue, for several reasons:
      a.  There is an explanation of the code that you can download from http://www.cuj.com/
      b.  It is important to read papers that treats VCL
      c.  You make me happy

2) Submit some code (that you just can download from CUJ site

3) Find bugs

4) Send me a lot of money

5) Go to the survey page

Example

If you design a form like the following one (click over the image to see it at full size):

and then you convert it with Dfm2API (release 1.2.1), you’ll obtain the following DialogBox (click over the image to see it at full size):

As you can see, even if there are small differences, they are quite similar. Also a lot of controls are initialized, with no need to write code, because Dfm2API did it for you. The main differences are:

1. No text AND glyphs on buttons (see for example Ok and Cancel Buttons). This is due to the fact that there is no equivalent standard control. I'm confident to partially fix this in release 1.5 with an Uncommon Control.
2. No border around scrollbars. Is it relevant?
3. No bitmap stretch. This has been fixed in 1.2.2
4. Different StatusBar behavior.
5. SpinEdit control different alignment (left/right). But this is intentional because I do prefear right alignment!

The jumping red animal is an Animation control captured in a different frame with respect to the previous one. So, the behaviour is correct!

Despite these differences (some of them are already fixed or will be soon), I think that this tool does much more than one could expect. I've received so many E-Mails that I'll surely continue to develop and update it (also because I'm using it everyday, also with different releases, such as the VCL2OWL one!). Anyway, I haven't received any code proposal, and for this reason I don't think that I'll release the sources any more.

Code Example

Click here to give a look at the automatically generated source code file from the proviously described Form (release 1.0).

History

Downloads

The project with the source code relative to release 1.0 is available at CUJ site.
You can download the main releases here.

Status

I've almost fixed the overall Form resizing: the default one generates DialogBoxes whose size differs from the original Form by less than 0.4%. As you probably know VCL Forms use a different sizing approach with respect to SDK DialogBoxes. I think I have understood the reason of the few remaining pixels. You can, of course, adapt the resizing feature at your wish, thus getting the best results. Actually I've improved VisualC compatibility and UNICODE and Windows CE support (since 1.2.1). I'm also working on the automatic generation of simple example programs for BCB, VC and GCC and more aspects related to UI.
I'm also working at PropertyPages and PageControls. (~1.5.0)

© Copyright (2000), Luigi Bianchi
Last Update: September 28, 2001