TweetFollow Us on Twitter

PowerPlant
Volume Number:11
Issue Number:9
Column Tag:Getting Started

PowerPlant

By Dave Mark, MacTech Magazine Regular Contributing Author

Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.

This month, we’re going to take a look at PowerPlant, the framework included on every CodeWarrior CD. If you own Symantec C++, take heart: we’ll get to the TCL in a future column. In the meantime, follow along anyway. Who knows, you might find yourself making the switch to PowerPlant someday.

This Month’s Program

I don’t know about you but, after four month’s straight of menus, I’m ready for something else. So instead of talking about PowerPlant and menu handling (we’ll do that in a future column), this month’s program will introduce PowerPlant’s messaging system.

As you design your PowerPlant programs, you’ll work with objects called broadcasters and listeners. A broadcaster sends a message and a listener receives that message. In this month’s program, we’ll create a window containing a button. Each time the button is clicked, it will send a message to any objects registered as listeners to it. Basically, this means that the broadcasting objects’ BroadcastMessage() member function calls the listening object’s ListenToMessage() member function.

This mechanism is simpler than it sounds. As we build our project, just remember that the button is a broadcaster, and that the class CDashboardApp will be the listener.

If you have the CW6 documentation, you might want to read the section named LBroadcaster & LListener in the PowerPlant manual (chapter 8, page 93).

As is usually the case when working with a framework, we’ll take an existing PowerPlant example and modify it to suit our needs.

• Duplicate the folder “CodeWarrior6:Metrowerks PowerPlant:More PowerPlant Examples:Dashboard Starter”.

If you run one of the projects in this folder (either Dashboard68K.µ or DashboardPPC.µ), you’ll see the window shown in Figure 1. To quit the program, select Quit from the File menu. As you can see, Quit is the only item in the File menu. In a future column, we’ll add some menus and items to a PowerPlant program. For now, let’s add a button to the Dashboard window.

Figure 1. The Dashboard Starter window, before our modifications.

Editing Dashboard.PPob

CodeWarrior comes with a ResEdit-like program, named Contructor, that lets you create and edit PowerPlant-specific resources. The resource we’re interested in in this column is the PPob resource. A PPob resource is like a combination of a DLOG and DITL, but for any PowerPlant view including windows and dialogs. We’ll use Constructor to add a button to the Dashboard window.

CodeWarrior 6 ships with two different versions of Constructor. Though both will do the job, Constructor 2.0a16 is far newer than Constructor 1.0.1 and seems pretty stable for an alpha release. The screen shots and instructions in this column were all based on 2.0a16. You’ll find both versions in the CodeWarrior 6 folder, inside the Metrowerks PowerPlant subfolder.

• Launch Constructor 2.0a16 and open the file Dashboard.PPob (it’s in the same folder as the two Dashboard project files).

As you can see by the Constructor window shown in Figure 2, the file Dashboard.PPob already contains a resource. This PPob resource represents the main Dashboard window. It has a resource ID of 200 and represents an object belonging to the class LWindow.

Figure 2. The Constructor window listing the view resources in Dashboard.PPob.

Our next step is to edit this PPob resource.

• Double-click on the LWindow PPob with an id of 200.

When you double-click on PPob 200, a PPob editing window will appear (see Figure 3) showing the object view hierarchy defined by this PPob. Right now, the PPob consists of a single window.

Figure 3. A Constructor window showing PPob 200.

If you click on the window view and select Pane Information... from the Pane menu (or just double-click on the window view), a pane info window will appear (see Figure 4) allowing you to edit the selected view. In this case, the selected view describes a document window with a zoom box, no close box, positioned automatically in the Alert position on the main screen, etc. Feel free to edit this view if you like. To test your changes, quit Constructor, saving your changes, then use CodeWarrior to rerun the project.

Figure 4. The Pane Info window describing the Dashboard window.

Figure 5. The items you can place in a window using Constructor.

With the PPob 200 window in front, you should notice a palette window listing all the items you can place in a PPob view. The palette, shown in Figure 5, works just like ResEdit’s DITL palette. To add an item to a view, drag the item off the palette into the PPob window.

Here’s where we’ll add the button to the window.

• Drag an LStdButton off of the palette into the window view in the PPob 200 window.

• Double-click on the button that appears and edit the info window to match the one shown in Figure 6.

Figure 6. The info window for the LStdButton we added to our window view.

There are three important changes to make in the LStdButton info window. First, change the Pane ID: field to read 1000 (be sure the Text ID checkbox is unchecked before you change the ID). The Pane ID serves to identify the button pane from all the other panes in the PPob resource. By convention, number your panes starting at 1000 and moving upwards from there. For example, if you added three items to the Dashboard window represented by PPob 200, you’d set their Pane IDs to 1000, 1001, and 1002.

The second change to make to the LStdButton info window is to fill in the Button Title: field. Since we want our button to beep, the word Beep will make a fine button title.

The third change is to the Value Message: field. This field contains the message that will get sent when the button is clicked. The message is an integer constant that will be passed as a parameter to any objects registered as listeners to the broadcasting button. Again, by convention, we’ll number our messages starting at 1000.

That’s it. Save your changes and quit Constructor.

Dashboard68K.µ or DashboardPPC.µ

If you haven’t already, open up one of the Dashboard projects (either Dashboard68K.µ or DashboardPPC.µ). Since we want to add a button to our window, we’ll need to add the files that contain the PowerPlant classes that implement push buttons: LControl.cp and LStdControl.cp.

• In the project window, click on the triangle to the left of the group named Pane. When we add the two files, we want to add them to this group.

• Add the files LControl.cp and LStdControl.cp to the project. You’ll find them in the folder “CodeWarrior 6:Metrowerks C/C++:PowerPlant Libraries:Pane Classes”

CDashboardApp.h

• Open the file CDashboardApp.h.

• Add this line after the #include of <LApplication.h>:

#include <LListener.h>

• Change the first line of the CDashboardApp class to look like this:

class CDashboardApp : public LApplication, public LListener {

To convert the CDashboardApp class into a listener, we have to make sure it is derived from the class LListener. Deriving a class from more than one class is perfectly acceptable in C++ and is known as multiple inheritence.

Another step in making the CDashboardApp class a listener is to add a member function named ListenToMessage(). ListenToMessage() will get called when any broadcaster it is listening to broadcasts a message.

• Add this line after the definition of the member function FindCommandStatus():

 virtual void    ListenToMessage(MessageT inMessage, void *ioParam);

• Close CDashboardApp.h and save your changes.

CDashboardApp.cp

Here’s where all the action is. Take some time to look through the file and read all the comments (don’t worry, the file isn’t that long). Notice that main() defines a CDashboardApp object and then calls the member function Run() which was inherited from the LApplication class.

• Add this line after all the other #include files:

#include <LStdControl.h>

Notice that even though we added the files LStdControl.cp and LControl.cp to the project, we don’t include the file <LControl.h>. <LControl.h> is included by <LStdControl.h>.

• In the constructor, find the call of the static function URegister::RegisterClass() and add this line right below it:

 URegistrar::RegisterClass(LStdButton::class_ID,
 LStdButton::CreateStdButtonStream);

This line tells PowerPlant which function to call (LStdButton::CreateStdButtonStream()) when an object of type LStdButton is created based on a PPob resource. Before we came along, this program only needed to register the LWindow class. Since we added an LStdButton object to the PPob resource, we’ll need to register that class as well.

• Also in the constructor, just before the call of mDisplayWindow->Show(), add these lines:

 LStdButton *theButton =
 (LStdButton *)mDisplayWindow->FindPaneByID( 1000 );
 theButton->AddListener( this );

The first line searches the window mDisplayWindow for the pane with the id 1000. Now you know why we entered the number 1000 in the LStdButton’s Pane ID: field.

The second line registers the current object (the CDashboardApp object, known here as this) as a listener of the button we just found.

• At the end of the file, add the member function CDashboardApp::ListenToMessage():

// ----------------------------------------------------------
// • ListenToMessage
// ----------------------------------------------------------
// Respond to message 1000 broadcast by pushbutton

void
CDashboardApp::ListenToMessage(MessageT inMessage, void *ioParam)
{
 if ( inMessage == 1000 )
 SysBeep( 20 );
}

This function will get called whenever the button is clicked. The message 1000 will be passed in as the parameter inMessage.

Figure 7. The Dashboard window. This time it has a button in it.

Running the Program

That’s about it. Save your changes and run the program. The usual Dashboard window will appear, but this time with a button smack-dab in the middle of it. Press the button and, guess what, your Mac will beep at you.

Till Next Month

Obviously, this month’s program gives you only a brief glimpse into the PowerPlant framework. On the other hand, it’s a pretty solid glimpse. Try your hand at adding some other panes to the Dashboard window containment hierarchy. Start by adding a second button with its own pane ID and its own message ID. Next, try to add some other controls.

What part of PowerPlant would you like to learn about next? Should I get into other control types? How about (shudder) menus? Send email. I’ll be waiting to hear from you. See you next month...

 
AAPL
$116.47
Apple Inc.
+0.16
MSFT
$47.98
Microsoft Corpora
-0.72
GOOG
$537.50
Google Inc.
+2.67

MacTech Search:
Community Search:

Software Updates via MacUpdate

Cobook 3.0.7 - Intelligent address book....
Cobook Contacts is an intuitive, engaging address book. Solve the problem of contact management with Cobook Contacts and its simple interface and powerful syncing and integration possibilities.... Read more
StatsBar 1.9 - Monitor system processes...
StatsBar gives you a comprehensive and detailed analysis of the following areas of your Mac: CPU usage Memory usage Disk usage Network and bandwidth usage Battery power and health (MacBooks only)... Read more
Cyberduck 4.6 - FTP and SFTP browser. (F...
Cyberduck is a robust FTP/FTP-TLS/SFTP browser for the Mac whose lack of visual clutter and cleverly intuitive features make it easy to use. Support for external editors and system technologies such... Read more
Maya 2015 - Professional 3D modeling and...
Maya is an award-winning software and powerful, integrated 3D modeling, animation, visual effects, and rendering solution. Because Maya is based on an open architecture, all your work can be scripted... Read more
Evernote 6.0.1 - Create searchable notes...
Evernote allows you to easily capture information in any environment using whatever device or platform you find most convenient, and makes this information accessible and searchable at anytime, from... Read more
calibre 2.11 - Complete e-library manage...
Calibre is a complete e-book library manager. Organize your collection, convert your books to multiple formats, and sync with all of your devices. Let Calibre be your multi-tasking digital... Read more
Herald 5.0.1 - Notification plugin for M...
Note: Versions 2.1.3 (for OS X 10.7), 3.0.6 (for OS X 10.8), and 4.0.8 (for OS X 10.9) are no longer supported by the developer. Herald is a notification plugin for Mail.app, Apple's Mac OS X email... Read more
Firetask 3.7 - Innovative task managemen...
Firetask uniquely combines the advantages of classical priority-and-due-date-based task management with GTD. Stay focused and on top of your commitments - Firetask's "Today" view shows all relevant... Read more
TechTool Pro 7.0.6 - Hard drive and syst...
TechTool Pro is now 7, and this is the most advanced version of the acclaimed Macintosh troubleshooting utility created in its 20-year history. Micromat has redeveloped TechTool Pro 7 to be fully 64... Read more
PhotoDesk 3.0.1 - Instagram client for p...
PhotoDesk lets you view, like, comment, and download Instagram pictures/videos! (NO Uploads! / Image Posting! Instagram forbids that! AND you *need* an *existing* Instagram account). But you can do... Read more

Latest Forum Discussions

See All

Ubisoft Gives Everyone Two New Ways to E...
Ubisoft Gives Everyone Two New Ways to Earn In-Game Stuff for Far Cry 4 Posted by Jessica Fisher on November 21st, 2014 [ permalink ] | Read more »
Golfinity – Tips, Tricks, Strategies, an...
Dig this: Would you like to know what we thought of being an infinite golfer? Check out our Golfinity review! Golfinity offers unlimited ways to test your skills at golf. Here are a few ways to make sure your score doesn’t get too high and your... | Read more »
Dark Hearts, The Sequel to Haunting Meli...
Dark Hearts, The Sequel to Haunting Melissa, is Available Now Posted by Jessica Fisher on November 21st, 2014 [ permalink ] Universal App - Designed for iPhone and iPad | Read more »
Meowza! Toyze Brings Talking Tom to Life...
Meowza! | Read more »
Square Enix Announces New Tactical RPG f...
Square Enix Announces New Tactical RPG for Mobile, Heavenstrike Rivals. Posted by Jessica Fisher on November 21st, 2014 [ permalink ] With their epic stories and gorgeous graphics, | Read more »
Quest for Revenge (Games)
Quest for Revenge 1.0.0 Device: iOS Universal Category: Games Price: $4.99, Version: 1.0.0 (iTunes) Description: The great Kingdom of the west has fallen. The gods ignore the prayers of the desperate. A dark warlord has extinguished... | Read more »
Threadz is a New Writing Adventure for Y...
Threadz is a New Writing Adventure for You and Your Friends Posted by Jessica Fisher on November 21st, 2014 [ permalink ] In the tradition of round-robin storytelling, | Read more »
SteelSeries Stratus XL Hardware Review
Made by: SteelSeries Price: $59.99 Hardware/iOS Integration Rating: 4 out of 5 stars Usability Rating: 4.5 out of 5 stars Reuse Value Rating: 4.25 out of 5 stars Build Quality Rating: 4.5 out of 5 stars Overall Rating: 4.31 out of 5 stars | Read more »
ACDSee (Photography)
ACDSee 1.0.0 Device: iOS iPhone Category: Photography Price: $1.99, Version: 1.0.0 (iTunes) Description: Capture, perfect, and share your photos with ACDSee. The ACDSee iPhone app combines an innovative camera, a powerful photo... | Read more »
ProTube for YouTube (Entertainment)
ProTube for YouTube 2.0.2 Device: iOS Universal Category: Entertainment Price: $1.99, Version: 2.0.2 (iTunes) Description: ProTube is the ultimate, fully featured YouTube app. With it's highly polished design, ProTube offers ad-free... | Read more »

Price Scanner via MacPrices.net

Save up to $400 with Apple refurbished 2014 1...
The Apple Store has restocked Apple Certified Refurbished 2014 15″ Retina MacBook Pros for up to $400 off the cost of new models. An Apple one-year warranty is included with each model, and shipping... Read more
New 13-inch 1.4GHz MacBook Air on sale for $8...
 Adorama has the 2014 13″ 1.4GHz/128GB MacBook Air on sale for $899.99 including free shipping plus NY & NJ tax only. Their price is $100 off MSRP. B&H Photo has the 13″ 1.4GHz/128GB MacBook... Read more
Apple Expected to Reverse Nine-Month Tablet S...
Apple and Samsung combined accounted for 62 percent of the nearly 36 million branded tablets shipped in 3Q 2014, according to early vendor shipment share estimates from market intelligence firm ABI... Read more
Stratos: 30 Percent of US Smartphone Owners t...
Stratos, Inc., creator of the Bluetooth Connected Card Platform, has announced results from its 2014 Holiday Mobile Payments Survey. The consumer survey found that nearly one out of three (30 percent... Read more
2014 1.4GHz Mac mini on sale for $449, save $...
 B&H Photo has lowered their price on the new 1.4GHz Mac mini to $449.99 including free shipping plus NY tax only. Their price is $50 off MSRP, and it’s the lowest price available for this new... Read more
Check Apple prices on any device with the iTr...
MacPrices is proud to offer readers a free iOS app (iPhones, iPads, & iPod touch) and Android app (Google Play and Amazon App Store) called iTracx, which allows you to glance at today’s lowest... Read more
64GB iPod touch on sale for $249, save $50
Best Buy has the 64GB iPod touch on sale for $249 on their online store for a limited time. Their price is $50 off MSRP. Choose free shipping or free local store pickup (if available). Sale price for... Read more
15″ 2.2GHz Retina MacBook Pro on sale for $17...
 B&H Photo has the 2014 15″ 2.2GHz Retina MacBook Pro on sale for $1799.99 for a limited time. Shipping is free, and B&H charges NY sales tax only. B&H will also include free copies of... Read more
New Logitech AnyAngle Case/Stand Brings Flexi...
Logitec has announced the newest addition to its suite of tablet products — the Logitech AnyAngle. A protective case with an any-angle stand for iPad Air 2 and all iPad mini models, AnyAngle is the... Read more
Notebook PC Shipments Rise Year-Over-Year as...
According to preliminary results from the upcoming DisplaySearch Quarterly Mobile PC Shipment and Forecast Report, the global notebook PC market grew 10 percent year-over-year in Q3’14 to 49.4... Read more

Jobs Board

*Apple* Solutions Consultant (ASC) - Apple (...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
*Apple* Solutions Consultant (ASC)- Retail S...
**Job Summary** The ASC is an Apple employee who serves as an Apple brand ambassador and influencer in a Reseller's store. The ASC's role is to grow Apple Read more
Project Manager, *Apple* Financial Services...
**Job Summary** Apple Financial Services (AFS) offers consumers, businesses and educational institutions ways to finance Apple purchases. We work with national and Read more
*Apple* Store Leader Program - College Gradu...
Job Description: Job Summary As an Apple Store Leader Program agent, you can continue your education as you major in the art of leadership at the Apple Store. You'll Read more
*Apple* Retail - Multiple Positions (US) - A...
Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, you're also the Read more
All contents are Copyright 1984-2011 by Xplain Corporation. All rights reserved. Theme designed by Icreon.