Using the Preview VBA in IntelliCAD.

By: Frank Zander
At: Contract CADD Group
Website: http://www.contractcaddgroup.com/
Email: frank.zander@contractcaddgroup.com
Phone: (604) 591-1140

This article explores some of the working and non-working parts of IntelliCAD's Preview VBA. The topics covered include; what is VBA, why one would want to use VBA in IntelliCAD, how to setup/access the preview VBA in IntelliCAD, how an object (line, circle, etc) is described by IntelliCAD's VBA object model, how Forms and controls on Forms act as VBA objects. For the adventurous, I have created a small "rubber stamp" program using working VBA code inside of IntelliCAD. This article was written for the non-programmer and hopefully the instructions will entice the non-programmer to try a hand at creating a simple "Rubber Stamp" program. For those who do not want to type in the code used in this article, the "Rubber Stamp" program is available for downloading at: www.contractcaddgroup.com/downloads.htm

Visual Basic for Applications (VBA) allows Visual Basic (VB) programmers to work in a familiar Visual Basic environment. Those not familiar with the Visual Basic environment will find that the interface is easy to use and straight forward.

Three reasons:

1. Speed

To quote Autodesk -- "VBA is fast. VBA is hosted by AutoCAD and doesn't have the associated overhead of calling out to a separate process. In internal benchmarks, VBA is significantly faster than AutoLISP® or Visual Basic running as a separate application. The execution speed is very close to a compiled C++ ObjectARX DLL-based extension." Programs created with Visual Basic for Applications execute faster than programs created outside of an application. For example, a VBA program will run faster than the same code setup as a standalone VB executable (exe) program.

2. Ease of use.

Visual Basic/VBA interface is easy to learn and use. VBA-enabled programs (e.g. Word 97, Office 97 Excel 97, AutoCAD 14, Visio Technical, IntelliCAD, etc) allow the user to learn and program in the same Visual Basic environment.

3. Universality

VBA has become broadly accepted as the Windows-based customization tool of choice. The VBA interface resembles Visual Basic 5 (VB5). IntelliCAD users only need to learn one programming environment (VBA) to be able to program with VB in all VBA enabled programs. The VBA editor included withIntelliCAD uses the same programming environment used in Office 97 applications. LISP only works in a handful of CADD programs, and is clunky, as well as hard to learn.

With Visual Basic, the programmer creates a user interface by adding controls from the Toolbox to a Form. To create a push button only requires a selection of the button control in the Toolbox and drawing/placing the control on a Form. It is very easy to create a Form that looks the way it will be used as a program. Buttons to push, Text boxes for entry, Option lists, etc, are a breeze to create, size, and change. The ability to rapidly create a prototype interface for a new program is stunning to say the least. Also, the resulting Form can be saved and imported into any Windows VBA-enabled program.

To setup IntelliCAD to run VBA, one needs to have the advanced Tools menu displayed. To get the Advanced Tools menu displayed, do the following:

1. From the pull down menus select Tools | Options…
2. In the Options dialog set the Experience level : Advanced
3. From the pull down menu select: Tools | Visual Basic (Preview)… | Visual Basic Editor

Or at the command prompt type: VBA 

Additionally, the Microsoft preferred methodology for launching the VBA environment is by pressing Alt + F11. This is fully supported in IntelliCAD, though not in AutoCAD R14.

Note: After you have done some work on your project it's a very good idea to save your project. IntelliCAD will not prompt you to save changes to a project when closing IntelliCAD. I ran into this "gotcha" the hardway. Luckily I only lost about a half an hour of programming. Save your program/project often and definitely save your project before you exit IntelliCAD!

To load an existing VBA project into IntelliCAD do the following:

1. From the pull down menu select: Tools | Visual Basic (Preview)… | Load Project…

Or at the command prompt type: VBALOAD

IntelliCAD loads IntelliCAD VBA Project (*.vbi) and/or AutoCAD r14 VBA Project (*.dvb) files. Also IntelliCAD can load multiple projects for editing at the same time. AutoCAD r14.01 can open only one at a time. It looks like, again, IntelliCAD understands Multiple Document Interface (MDI) better than Autodesk. Opening multiple drawings in IntelliCAD (MDI) makes editing drawings very productive. Opening multiple Projects for cutting and pasting code between projects makes programming remarkably productive. This is a very welcome innovation in IntelliCAD. Sample shipping VBI projects (for cutting and pasting code) can be located (using the typical/default IntelliCAD install) at: C:\Program Files\IntelliCAD 98\Api\Vb\…

VBA uses Objects to work with documents. VBA describes everything within an IntelliCAD drawing (lines, circles, arcs, text, etc) as an Object. Every Object in a drawing then has properties. A line within the current drawing has a color property that would be described as Thisdocument.lineobj.color. Most of the VBA in IntelliCAD to describe or modify drawing objects does not work. I was extremely fortunate to find and use the Mtext object for the "Rubber Stamp" project. I had no luck whatsoever in getting the Text object to create text within an IntelliCAD drawing. Possibly, I missed something. The VBA preview in IntelliCAD did not work as I had hoped or expected. The lack of documentation for the preview VBA in IntelliCAD made it a struggle to create the "Rubber Stamp" project. The preview VBA in IntelliCAD for using Forms works wonderfully. The documentation for Forms in the IntelliCAD help-system is extensive and well thought out. Every object (button, textbox, combobox, etc) on a Form becomes a sub-object of the Form. As an example… the TextBox1 on UserForm1 is described as:

To set the text information in TextBox1 on UserForm1 to display the current drawing name with the path, use the following code:

Easy! For the curious owners of IntelliCAD, a picture of the IntelliCAD VBA Object model can be found in the file directory C:\Program Files\IntelliCAD 98\Api\Vb\ IcadObjectModel.jpg.

In planning this article, I wanted to create a simple program that would be useful to all IntelliCAD users and not be specific to one discipline (e.g. Mechanical, Structural, or Architectural, etc.). I also wanted to create a very simple program that would be easy for the non-programmer to create and understand. Hopefully I have achieved this with the "Rubber Stamp" program. The "Rubber Stamp" program gets the drawing name and path information from the active document. The current Windows system time is captured and several items are presented to the user to select the type of "Stamp" to place on the drawing. The Rubber Stamp program then places an Mtext object in the drawing when the user presses the Stamp button. The resulting Mtext object is placed in the drawing at coordinates 1,1 with the drawing information as shown in the "Rubber Stamp" user interface. For this example, the information is:

To make the "Rubber Stamp" project:

1. At the IntelliCAD command prompt type: VBA.
2. Create a Form. From the pull-down menus in the VBA interface select Insert | UserForm.
3. From the Properties Window (press F4 to activate) change the Caption of the UserForm1 to "Rubber Stamp".
4. Create the Exit command button; select the command button control from the Toolbox, place your mouse over the Form and draw a rectangle to create the button.

 



5. Change the command button to display Exit rather than the current text CommandButton1. To change the text CommandButton1 to Exit look at the Properties Window (F4) displaying properties-commandbutton1 -- change the Caption information from CommandButton1 to Exit. Alternately slowly double click the CommandButton1 on the Form and edit the text in-place. The CommandButton1 should now display Exit.
6. Setup the click event on the Exit button... So far the command button is in location and shows "Exit", but does nothing. Why? You have not assigned an event to the command button. What is an event? An event is what happens when a user changes something or interacts with a program. The event you want to monitor is when the user clicks the Exit button. Double click the Exit command button quickly. Notice that VBA view window changes to a View Code window. Also notice that you are presented with the code following:

Private Sub CommandButton1_Click()

End Sub

In between the Private Sub CommanButton1_Click() and the End Sub is where you write code. Add the code Unload UserForm1.

7. Save your project…
8. Run the project. Press F5 or select the pull-down menu Run | Sub/UserForm.
9. To exit your program click the Exit button you just created.
10. Create the stamp button using the same technique described at step 4 above. Fill in the code for CommandButton2 as shown in the section The Code.
11. Create the Textbox1, TextBox2 and TextBox3 on the UserForm1 by selecting the TextBox control in the Toolbox and draw three textboxs on the Form.
12. Copy the code from Private Sub UserForm_Initialize() to End Sub to setup the information that is displayed in the Form as it is initialized (loaded).
13. Save your project…
14. Run the project. Press F5 or select the pull-down menu Run | Sub/UserForm.
15. Select the Stamp options combo box to choose the appropriate stamp type. Press the Stamp button to place the stamp in the drawing.
16. Note: The drawing will need to be regenerated and zoomed to the extents to see the stamp.

Editor’s Note: The preview edition of IntelliCAD 98’s VBA is a very limited subset of the available Objects, Methods and Properties. All of the IntelliCAD Objects, Methods and Properties are available to browse throughout the VBA Object Browser by pressing F2 from within the VBA IDE. The Objects are, for the most part, stubbed out and are not currently live. This will all be live in a future release.