# 2.3 - Adding the Code

## Creating the class's source and header files

Gorm.app can automatically create the skeleton of the class you've designed: select the ConvertorManager class in the Classes panel of the main window, and do Classes→Create Class Files.

![Classes→Create Class Files](2.3_nfig1.png)

Two successive Save Panels will pop up for the .m and the .h files. Gorm will propose as file names ConvertorManager.m and ConvertorManager.h, it is a good convetion to use the class name as a filename. Save those files into the Project directory.

![Save dialog](2.3_nfig2.png)

You may also safely delete the `AppController` object instance if you have it in your Gorm file.

Once this is done, remember to save the interface if you haven't yet, and go back to ProjectCenter.

## Creating the class's source and header files

Adding the class's source and header files to the current project

You now need to add the class's files to the project. Double-click <u>Classes</u> in the first column of the browser, choose the `.m` file to add to the project (`ConvertorManager.m`); the corresponding header file will be automatically added for you.

![Adding the class's source and header files to the project](2.3_ofig3.png)

## Writing the convert: method

Open the `ConvertorManager.m` file by slecting its name within ProjectCenter.app browser. You can display the file in the embedded view or, alternatively, double-clicking will open it in a separate editor.

You should see the following :

```objc
/* All Rights reserved */

#import <AppKit/AppKit.h>
#import "ConvertorManager.h"

@implementation ConvertorManager

- (void) convert: (id) sender
{
  /* insert your code here */
}

@end
```

Add the following inside the convert: method:

```objc
[result setFloatValue: [rate floatValue] * [amount floatValue]];
```

or if you want to have a nicer display:

```objc
[result setStringValue: [NSString stringWithFormat: @"%1.2f",
                            [amount floatValue] * [rate floatValue]]];
```

Save the file.

![Editing the class](2.3_ofig4.png)

You may safely remove the `AppController` class from your project, we are not using it.

## Compiling and running

Click ![Compiling Panel Button](2.3_icon_build.png) to dispay the building panel. Then click ![Build Button](2.3_icon_build.png) to build the project. If there is no errors (and hopefully there is none), you can run the application. To do it, click ![Run Panel Button](2.3_icon_run.png) to display the run panel. Then click the first button (at this time it has still no icon), this should launch the application :

![Converter.app running](2.3_ofig5.png)

Convertor.app in action, converting between Euro and US Dollar.

**Congratulations, you have completed your first GNUstep app!**