TCL and VA 2
| Volume Number: | | 11
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| Issue Number: | | 11
|
| Column Tag: | | Getting Started
|
TCL and Visual Architect, Part 2 
By Dave Mark, MacTech Magazine Regular Contributing Author
Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.
In last month’s column, we took a look at Symantec’s latest development environment, including the Symantec Project Manager and Visual Architect. Following the example presented in Chapter 14 of the Symantec C++ User’s Guide, we used Visual Architect to generate source code to implement the single, default view named Main. We then returned to the Symantec Project Manager and compiled the code into a standalone application (See Figure 1).
Figure 1. The window that appeared when we ran last month’s program.
This month, we’re going to add a second view to our program. This second view will be a dialog that allows you to type a number into an editable text field. When you press the Beep button, the dialog will beep the specified number of times.
Adding a Second View
Go into the Button ƒ folder you created last month and double-click on the file Button.Π to launch the Symantec Project Manager. When the project window appears, double click on the file name Visual Architect.rsrc to bring up Visual Architect. This is where we’ll add the second view.
• Select New View from the View menu.
• When asked to name the new view, type BeeperDialog and make sure Modal Dialog is selected from the View Kind: popup menu (Figure 2), then press the OK button.
Figure 2. Naming the new view.
The name BeeperDialog will be used as the basis for a new class, called CBeeperDialog. The next time you select Generate from Visual Architect’s Symantec Project Manager menu, Visual Architect will generate the files CBeeperDialog.cp, CBeeperDialog.h, x_CBeeperDialog.cp, and x_CBeeperDialog.h. First, we’ll add a few items to this dialog and then add a button to our Main view that brings up the dialog.
Once you press the OK button, a view window will appear with the name BeeperDialog.
• Select View Info from the View menu.
A view info window titled Dialog Info will appear (Figure 3). The view info window, which looks a lot like a ResEdit or Resorcerer WIND templat, lets you customize the look of your new dialog window.
Figure 3. The view info window for the BeeperDialog view.
• Click on the movable modal dialog icon (the second from the right) or type “5” in the procID: field.
• Click on the OK button to dismiss the dialog.
Your next step is to add some items to the dialog.
• Click on the Tools menu and drag down until the tool palette outline appears.
When you release the mouse button, the Tools palette window will appear (Figure 4). Take a few minutes to play with the items in this palette. In the top row, you have the selection tool, the text tool, and the editable text tool. The second row features the pushbutton tool, the radio button tool, and the check box tool. The third row features the popup menu, icon, and PICT tools. We’ll get into the rest of the tools in a future column. For now, try creating items based on the tools in the first three rows. Click on a tool, then click and drag in the BeeperDialog view window. Once you get a feel for these tools, select the selection tool (the arrow), then click on each of the items you added and press the delete key. Keep on deleting until the BeeperDialog window is empty again.
Figure 4. The Tools palette.
Now let’s add the items that make up the Beeper dialog. We’ll add four items: an OK button, a Cancel button, a static text label, and an editable text field for entering the number of beeps. We’ll start with the OK and Cancel buttons.
• Click on the button tool in the palette window.
• Click on the BeeperDialog window and drag out an OK button.
As you drag, keep your eye on the lower left corner of the window. Notice that the two coordinates listed reflect the upper left and lower right corners of the button. I made my button 80 pixels wide and 20 pixels tall with an upper left corner of (200,42).
• Click on the BeeperDialog window and drag out a Cancel button.
My Cancel button was also 80 pixels wide and 20 pixels tall. This time, the upper left corner was (107,42). Notice that VA automatically filled in the text OK for the first button and Cancel for the second button. Nice feature! Let’s change the OK to say Beep.
• Double-click on the OK button (or click on it and select Pane Info... from the Pane menu) to bring up the Pane Info window.
• Click on the triangle to the left of the class name CControl, revealing the CControl data members.
• Change contrlTitle from OK to Beep and close the Pane Info window.
Notice that the button’s name changed from OK to Beep. Now let’s add the static text label.
• Click on the static text tool (the big letter A) in the palette window.
• Click in the BeeperDialog window and type the text Number of times to beep:
• Click outside the static text to stop entering text, then click on the static text to select it. Drag it to a satisfactory position in the BeeperDialog window.
I dragged my static text so its upper-left corner was at (23,13). You might want to use the arrow keys to move the static text around the window, 4 pixels at a time. Hold down the command (Apple) key to get the arrow keys to move 1 pixel at a time. Experiment with the Shift and option keys which let you resize an item by 1 or 4 pixels in any of 4 directions.
Finally, let’s add an editable text field.
• Click on the editable text tool (to the right of the static text tool) in the palette window.
• Click on the BeeperDialog window and drag out an editable text area.
Mine had and upper left corner of (205,13) and a lower right of (280,29). Once your items are in place, resize the dialog view so it comfortably encloses the dialog items. To do that, click on the handle in the lower-right corner of the grey rectangle embedded in the BeeperDialog window. Drag the handle to its new position. I dragged mine to (293,75). The finished Beeper dialog is shown in Figure 5.
Figure 5. The finished Beeper dialog with the Beep button selected.
If you like, you can try the dialog out by selecting Try Out from the View menu. Click on one of the buttons or select Close from the File menu to close the Try Out window once you are done admiring your handiwork.
Our next task is to tell VA that our edit-text field is designed to hold only integers (as opposed to any old text).
• Click on the editable text field.
• Select Class from the Pane menu, then select CIntegerText from the submenu that appears.
Next, we need to define a new command that will get sent when the Beep button is clicked. Right now the Beep button’s command is set to cmdOK. To see that, double-click on the Beep button to bring up the Pane Info window, then click on the CButton triangle. Take a look at the Command popup menu. If you click on it, you’ll find a whole bunch of commands, all of them built into the TCL. Since there is no Beep command, we’ll need to define it ourselves, then set the Beep button to send it when clicked.
• Close the Beep Pane Info window, if you opened it to look at the Command popup.
• With the BeeperDialog window frontmost, select Commands... from the Edit menu.
• When the Commands window appears, select New Command from the Edit menu.
• Type cmdBeep in the uppermost editable text field.
• Select CBeeperDialog from the In Class: popup menu.
This tells VA which class this command belongs to.
• Select Call from the Do: popup menu.
This tells VA what you want done in response to this command. You could do nothing, you could ask VA to call a function, or you could open another view. In our case, we’ve asked VA to call a CBeeperDialog member function. We’ll get to that function in a bit.
Notice that VA automatically generated the command number 512. This is not particularly important. You’ll use the constant cmdBeep instead of 512, so there’s no reason to memorize your command numbers.
• Click on the OK button to dismiss the Commands dialog.
As you’ve probably guessed, your next step is to associate the cmdBeep command with the Beep button.
• Double-click on the Beep button to bring up the Pane Info window.
• Click on the triangle to the left of the class CButton, revealing the Command popup menu.
• Select cmdBeep from the Command popup (Figure 6).
• Close the Pane Info window.
Figure 6. The Pane Info window associated with the Beep button.
Notice that the Command popup has been set to cmdBeep.
You may have noticed that the Beep button no longer has the bold, rounded rectangle around it, specifying it as the default button, the button pressed when the user hits return. This changed because VA specifies the cmdOK command as the default. Let’s fix that.
• Select Set Default Command from the View menu.
• Select cmdBeep from the Command popup menu, then press OK.
Notice that the bold, rounded rectangle is back around the Beep button (Figure 7).
Figure 7. The BeeperDialog window, once cmdBeep is set as the default command.
We are almost done! Now we have to add a button to the Main view that brings up the Beeper dialog.
• Close the BeeperDialog view window.
• Double-click on Main in the view list window to bring up the Main view window.
• Click on the grow box in the lower left corner of the Main view window and drag down about 50 pixels.
• Click on the handle in the lower right corner of the grey bounding rectangle inside the window and drag it down about 50 pixels.
You’ve just resized the Main view to be about 50 pixels taller, making room for a new pushbutton.
• Click on the pushbutton tool (under the arrow) in the palette window.
• Click in the Main view window and drag out a new button below the PICT.
• Before you click off the button, type the word Beeper...
The button will now bear the name Beeper....
• Double-click on the Beeper... button, bringing up the button’s Pane Info window.
• Click on the triangle next to the class name CButton to reveal the CButton data members.
• Choose Other... from the top of the Command popup menu.
• When the Commands dialog appears, choose New Command from the Edit menu.
• Enter the command name cmdBeeperDialog.
• Choose CMain from the In Class: popup menu to let VA know you want the new command associated with the CMain class.
• Choose Open from the Do: popup menu.
• Choose CBeeperDialog from the View: popup menu.
We’ve just told VA that we want this new command (cmdBeeperDialog) to open the CBeeperDialog view (See Figure 8).
Figure 8. The Commands window for the new cmdBeeperDialog command.
• Click on the OK button.
Now we’ve told VA to associate this command with the Beeper... button we just created.
• Close the button’s Pane Info window to return to the Main view window (Figure 9).
Figure 9. My Main view with my new Beeper... button.
If you like, select Try Out from the View menu and take your new version of Main for a spin. Note that we haven’t put the code in place that gets called when the Beeper... button is pressed, but the scrollbars should work and the button should highlight when clicked.
Our next step is to ask VA to regenerate our source code, reflecting the new panes and commands we’ve defined.
• Select Generate... from the Symantec Project Manager menu (diamond shaped menu to the right of the Windows menu).
• When prompted to save your changes, click OK.
VA will update your existing code base. If you selected Generate All..., VA would have replaced your existing code base. Be sure you understand this difference!
Adding the New Code
Our last step is to add a few lines of code to bring all our new interface elements together.
• Return to the Symantec Project Manager.
• In the project window, click on the triangle to the left of the folder labeled Source. Skip this step if the Source folder was already opened.
• Double click on the file name “CBeeperDialog.cp”.
• Add this code to the end of CBeeperDialog.cp:
void CBeeperDialog::DoCmdBeep()
{
long n;
n = fBeeperDialog_Edit15->GetIntValue();
for ( long i=0; i<n; i++ )
SysBeep( 20 );
}
This code references the data member fBeeperDialog_Edit15. When VA generates your code, it makes up a constant for each of your dialog items. You can find these definitions in the file BeeperDialogItems.h. Here’s the constants that were generated for my version of Beeper:
enum
{
BeeperDialog_Begin_,
kBeeperDialog_Butn12 = 1,
kBeeperDialog_Butn12ID = 2049L,
kBeeperDialog_Butn13 = 2,
kBeeperDialog_Butn13ID = 2050L,
kBeeperDialog_Stat14 = 3,
kBeeperDialog_Stat14ID = 2051L,
kBeeperDialog_Stat17 = 4,
kBeeperDialog_Stat17ID = 2053L,
kBeeperDialog_Edit15 = 5,
kBeeperDialog_Edit15ID = 2052L,
BeeperDialog_End_
};
The member function GetIntValue() retrieves the value from the field that calls it (in this case, the editable text field), translates the value into an integer, and returns it. The loop uses this value to beep the specified number of times.
• Go to the top of the file and remove the comment characters (//) at the beginning of the line:
// #include “AppCommands.h”
You’ll need to do this last step whenever your view includes at least 1 command.
• Close CBeeperDialog.cp.
That’s it! When you run the program, the Main view should appear, featuring a brand new button (Figure 10).
Figure 10. The Main view, with the Beeper... button pressed.
Press the Beeper... button. The Beeper Dialog will appear.
Type a number in the text field and press the Beep button. Happy?
Figure 11. Pressing the Beep button.
Till Next Month...
Next month, we’ll go back to PowerPlant. I just got my copy of CW7, and I’m anxious to dig into it. Hope you got your upgrades, too. See you next month...
