|Column Tag:||Getting Started
PowerPlant and TextEdit
By Dave Mark, MacTech Magazine Regular Contributing Author
Note: Source code files accompanying article are located on MacTech CD-ROM or source code disks.
Over the next few months, were going to implement a TextEdit application using PowerPlant. Well start off this month by implementing a classic TextEdit window with a single text style. Next month, well add the code to save and open documents created with this application.
Planning Our Project
Lets take a look at the steps well need to take to implement a TextEdit window in a PowerPlant application. Well need to:
Create a new project using the PowerPlant stationery.
Replace the stationery Constructor file with a copy we saved in our project folder.
Replace the stationery source code files in the project (both the main .cp file and its corresponding .h file) with copies of the files we save in our project folder.
Use Constructor to create a TextEdit window view in our project resource file.
Modify the source code to base the default window on the new view. This last change is only one line of code.
Before you read on, take some time to try this yourself. At this point, you should know enough about PowerPlant to implement the project yourself without step-by-step instructions (dont worry, well get to the step-by-step instructions in a minute, just in case). More than likely, if you need help, it will be with the fourth step, creating a TextEdit view in Constructor. Heres a hint. First create an LWindow, then add an LScroller to the LWindow, then add an LTextEdit inside the LScroller. Go back and check out the PictScroller project (MacTech 11.12) if you need a refresher.
Before you continue, check to see which version of Constructor you have. You shoul;d be using Constructor 2.0.1 or later. CW7 shipped with Constructor 2.0, which has a bug which directly affects this project. Basically, Constructor 2.0 doesnt always save ppop resources correctly, and you can end up with some funky results. Fortunately, upgrading to Constructor 2.0.1 is painless. Get on the web and check out:
About halfway down the page, youll find and ftp URL for the Constructor 2.0.1 update. Donwload the updater and bring your Constructor back to the future.
Creating the PPEdit Project
OK, here are the step-by-step instructions I promised. Well start off by building our project and replacing the stationery files:
Create a new folder called PPTextEdit.
Launch CodeWarrior and create a new project named PPTextEdit.µ, using the PowerPlant stationery.
In the project window, double-click on the file <PP Starter Resource>.rsrc. This will open the file in Constructor.
In Constructor, do a Save As... and save the file in the PPTextEdit folder as PPTextEdit.rsrc.
As mentioned in last months column, this last step tells Constructor to completely duplicate the file, and not just the resources it uses. This is definitely the right way to replace the stationery resource file.
By the way, the new PowerPlant manual (youll find it on the CW8 CD) has a cool tip concerning PowerPlant resource files. When you create a new PowerPlant project, divide your resources into two groups. Put all the Constructor-related resources in one resource file (give it the creator code 'MWC2') and put all your other resources in a second resource file (give it the creator code 'RSED' if you use ResEdit or 'Doug' if you use Resorcerer). This way, when you double-click on your Constructor resource file, Constructor will be launched, and when you double-click on your regular resource file, your favorite resource editor will be launched.
Quit Constructor and return to CodeWarrior.
Add the file PPTextEdit.rsrc to the project.
Delete the file <PP Starter Resource>.rsrc from the project.
In the project window, double-click on the file <PP Starter Source>.cp.
Select Save As... from the File menu and save the file as PPTextEdit.cp in the PPTextEdit folder.
Scroll to the top of PPTextEdit.cp and find the line:
#include "<PP Starter Header>.h"
Select everything between the quotes (dont select the quotes) and type AppleD (Open Selection from the File menu). This opens the stationery file <PP Starter Header>.h.
Select Save As... from the File menu and save the header file as PPTextEdit.h in the PPTextEdit folder.
Change the #include to read:
Select Preferences... from the Edit menu and scroll to either the 68K Project or PPC Project pane, depending on which machine you are developing for.
In the Application Info area, change the File name to PPTextEdit and use the 'SIZE' flags popup to make the menu look like the one in Figure 1.
Figure 1. Be sure your SIZE flags are set like this in the CodeWarrior preferences (see the PPC Project or 68K Project pane).
This last step ensures that your application supports high level events. If your app supports high level events, PowerPlant sends an 'oapp' Apple event when the application starts up. This causes the function CPPStarterApp::StartUp() to get called which, in turn, issues a cmd_New command. Simply put, if your applications 'SIZE' flags dont indicate that your app is high level event-aware, a new window wont appear at startup.
Creating the TextEdit View in Constructor
Our next step is to create the new TextEdit view in Constructor.
In the CodeWarrior project window, double-click on the file PPTextEdit.rsrc to launch Constructor.
In the main window, click on the default LWindow (ID 1) and press the Delete key to get rid of it. The main window should now be empty.
If you are using the version of Constructor that shipped with CW8 (2.1a1 or later), the main window looks a little different. Instead of a scrolling list of icons, each of which has an associated list of resources, the new Constructor (see Figure 2) features collapsing triangles, as well as a menu editor, so you can edit your menus without leaving Constructor. Very cool!
Figure 2. This months Constructor file, as seen in the version of Constructor that shipped on Januarys CW8 CD.
Select New Resource from the Edit menu to create a new LWindow view.
Give the new view a resource ID of 1000 and a name of TextEdit.
In the old Constructor, youll need to click on the view in the main window and select Resource Info from the Edit menu (AppleI) to change the resource ID. In the new Constructor, you can enter the resource ID when you first create the view. Much better.
In the main window, double-click on the new view to open the TextEdit views editing window.
The view editing window will contain a single window. Double-click on the title bar of that window to bring up the TextEdit views pane info window.
Change the pane info window to match the settings shown in Figure 3.
Close the pane info window (leaving the view-editing window open).
PowerPlant terminology reminder: All things are panes. Some panes are also views. A view is a pane that can enclose other panes. So a window is a pane that happens to also be a view. A control is a pane and is never a view (you cant embed a pane inside a control pane).
Figure 3. The resource info for the TextEdit LWindow view.
Drag an LScroller from the palette onto the window in the view editing window.
Double-click the LScroller to bring up its pane info window.
Change the LScrollers pane info window to match the settings shown in Figure 4.
Be sure to enter -1 in the horizontal scroll bars left indent field. This tells PowerPlant to leave out the scroll bar on the bottom of our TextEdit window.
Note that we assigned the LScroller a pane ID of 1001. Also, note that we entered a Scrolling View ID of 1002. This second ID tells Constructor and PowerPlant which pane we want controlled by this LScroller. Well create an LTextEdit pane next and give it an ID of 1002.
Close the LScrollers pane info window (leaving the view-editing window open).
Figure 4. The pane info for the LScroller. Note that the horizontal scroll bar was disabled.
Drag an LTextEdit from the palette onto the LScroller in the view editing window.
Double-click the LTextEdit to bring up its pane info window.
Change the LTextEdits pane info window to match the settings shown in Figure 5.
Figure 5. The pane info for the LTextEdit pane. Note that the TextTraits ID is set to 1002. Well create a new Text Trait resource just for this LTextEdit.
Note that the LTextEdit has a pane ID of 1002. Thats to connect it to the LScroller. Note also that the Text Traits ID is set to 1002. In a moment, well create a text trait resource (with an ID of 1002) that specifies the format of the text drawn in this LTextEdit pane.
Close the LTextEdits pane info window (leaving the view editing window open).
Close the view editing window for our LWindow, leaving the main window open.
Select Show Hierarchy from the Display menu.
When the hierarchy appears, be sure that it matches the hierarchy shown in Figure 6, with the LScroller embedded in the LWindow and the LTextEdit embedded in the LScroller.
Figure 6. The pane/view hierarchy, showing the LScroller embedded in the LWindow and the LTextEdit embedded in the LScroller.
Close the hierarchy window.
In the main window, click on the Text Traits icon (as opposed to the Views icon).
Create a new text trait resource by selecting New Resource from the Edit menu.
Change the text trait settings to match those shown in Figure 7.
Figure 7. The specifications for our text traits resource.
Close the Text Traits window.
In the main window, click on the new Text Trait you just created, then select Resource Info from the Edit menu.
Change the resource ID of the new text traits resource to 1002.
Close the resource info window.
If you are using the new Constructor, your method for creating a new text trait resource will be slightly different. In the main window, click on the main Text Traits heading, then select New Text Traits Resource from the Edit menu. When the new resource appears in the list, double-click on it to open the trait editing window, or click on it and select Resource Info from the Edit menu to edit the resource info.
Save your changes, then quit Constructor.
One Slight Source Code Change
One slight source code change, then were done. All we have to do is change the constant that tells the application which view to open on startup. The PowerPlant stationery sets things up so the 'ppob' resource with an ID of 1 is used as the basis for the applications default window. All we need to do is change the 1 to 1000, so our LWindow 1000 will get used instead.
Back in CodeWarrior, open up the source code file PPTextEdit.cp.
Towards the top of the file, youll find the line:
const ResIDTwindow_Sample = 1;// EXAMPLE
Change the 1 to a 1000, so the line reads:
const ResIDTwindow_Sample = 1000; // EXAMPLE
Running the Application
Thats it! Your application is now ready to rock and roll.
Select Run from the Project menu.
After your source code is compiled and the project is linked, your new TextEdit application will run and a new TextEdit window will appear. Click in the window, then type in a bunch of text. Notice that the text appears in red, 9-point Geneva. As is, PowerPlant does not yet support styled TextEdit, though there are some third-party classes available that do. Im guessing that well see styled TextEdit built in to PowerPlant before too long.
Try creating multiple windows (select New from the File menu) and copy and paste between the windows. This is cool. You get a lot for free with PowerPlant.
Till Next Month...
One thing youll notice is that our application has no way of saving the text to disk or loading the contents of a file into a window. Guess what well be doing next month. Till then, get hold of the PowerPlant manual (a great job of writing by Jim Trudeau, by the way), and start reading about the LDocument class.