Renaissance—A Cross-Platform Development Tool for Linux and Mac OS X

Under Mac OS X, we are sharing the main gsmarkup file with the GNUstep version of our application, so we now have to create the gsmarkup file used for our sample application menu, for Mac OS X. Doing so allows us to have a different menu for Mac OS X, which is required because the layout of menus under GNUstep (vertical) is different from the one on Mac OS X (horizontal). Create the file Cocoa-Menu.gsmarkup with the content shown in Listing 6.

<gsmarkup>
  <objects>
    <menu type="main">
      <menu title="TiffViewer" type="apple">
        <menuItem title="Hide TiffViewer"
                     key="h"
                     action="hide:"/>
        <menuItem title="Quit TiffViewer"
                     key="q"
                     action="terminate:"/>
      </menu>
      <menu title="File">
        <menuItem title="Load Image"
                     action="loadImage:"/>
      </menu>
    </menu>
  </objects>
</gsmarkup>

In Listing 6, we also define three menu items: Hide TiffViewer, Quit TiffViewer and Load Image. Contrary to GNUstep, we create the first two under the TiffViewer menu, to be displayed in bold (notice the type="apple") and the latter under the File menu. We do this because the menu disposition on Mac OS X is different from GNUstep, and we want to follow the HIG at least with regard to the menus.

Once the file has been created, we need to create the Mac OS X project file and build the application. To do so, start the Project Builder application and proceed with the following steps:

Figure 2. The Image Viewing Application on Mac OS X

As you have seen in this section, porting the application from GNUstep to Mac OS X is rather trivial. No code changes were required. As under GNUstep, you can load a TIFF file in the application and try to resize the window. You should see the image view automatically resizing both horizontally and vertically, as specified in the main gsmarkup file. You also should notice the Apple-style horizontal disposition of the application menu, as shown in Figure 2.

As said before, Renaissance eases localization. In order to show how, let's translate our simple TIFF viewer to the French language. Renaissance automatically knows what to translate and what to maintain. In our menu gsmarkup files, each of the menu items had a title. Renaissance automatically uses the title of UI elements as a key in the Localizable.strings files to get the right translated string. In order to translate our sample application, create a French.lproj directory inside the project's root directory. In that newly created directory, create the Localizable.strings file with the content shown in Listing 7.