Using the Classic Application Environment


Classic applications look and feel, well... classic. When you run a Classic application, you see the application in the Platinum look of the venerable Mac OS 9. Side by side with OS X applications, Classic applications really feel old to you. A Classic application’s windows, menus, buttons, and all other controls have the Platinum look, and they work like Mac OS 9 windows, menus, buttons, and so forth.

The reason that Classic applications have the look and feel of Mac OS 9 is that the Classic application environment allows Mac OS X to concurrently run a booted copy of Mac OS 9. Before a Classic application can run, the Classic application environment must start up. This startup process is very similar to booting a Mac under Mac OS 9:

You actually see the “Welcome to Mac OS 9” message and the march of startup items (extensions and control panels), but these things appear within a Mac OS X window. (You can shrink the Classic startup window to show only a progress bar.) After the startup process completes, the startup window goes away and a strange yet systematic m lange of Platinum and Aqua GUI elements coexist on the screen. You see a gray Mac OS 9-style menu bar when you use a Classic application and an Aqua menu bar when you use a Mac OS X application. The Dock is still available at the bottom or the side of the screen, and your Classic application’s icons appear there. Because Mac OS 9 does not support the 128 x 128–pixel icons that Mac OS X does, your Classic icons do not look as crisp next to Mac OS X icons. Figure 17-1 shows an example of a Classic application in Mac OS X.

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Figure 17-1: Classic Applications like Scrapbook run alongside Mac OS X applications (Safari), but have the old Platinum look down to the jagged icon in the Dock.

Classic limitations

If you have more than one Classic program open at the same time, they share the Classic application environment using cooperative multitasking exactly as they do in Mac OS 9. Because of this, a Classic application can become sluggish when you have other Classic applications working in the background.

Classic applications don’t benefit from Mac OS X’s protected memory within the Classic application environment. This lack of protected memory means that if one Classic application fails, it may make other Classic programs that are open fail as well (or make the environment unstable). When a Classic program crashes, you may need to restart the entire Classic application environment and all the Classic programs you were using, much like when you were running Mac OS 9. Although individual Classic applications don’t benefit from protected memory and preemptive multitasking, the Classic application environment as a whole does. If the Classic application environment crashes, it won’t crash your entire computer. To Mac OS X, the entire Classic application environment (and all its running applications) is a single OS X process. If a Classic application quits unexpectedly, you have to restart the Classic application environment only, not the whole computer. Conversely, a problem in a Mac OS X application does not affect the Classic application environment or any Classic applications.

Perhaps the biggest limitation of the Classic application environment is a lack of support for most third-party hardware. This is because Mac OS X doesn’t allow Classic to access hardware directly, the way Mac OS 9 did. In fact, Mac OS X doesn’t give any application direct control of hardware, in order to maintain a stable environment. If you have any legacy peripherals that you need to use, make certain you update any applications or drivers your devices require for Mac OS X. If you don’t update them, you either have to reboot your machine and run Mac OS 9 when you want to access those devices, or upgrade to newer peripherals.

Classic preference pane

In Mac OS X’s System Preferences application, you find the Classic preference pane (see Figure 18-2). This preference pane is used to configure Classic preferences, allows you to start and stop the Classic environment, and gives you troubleshooting information and controls. The Classic preference pane has three panels: Start/Stop, Advanced, and Memory/ Versions. The Classic preference pane is found in the System grouping of the System Preferences application.

Using the Start/Stop panel

The Start/Stop panel contains the main controls of the Classic application environment. If you have multiple System Folders (on the same disk, different partitions, or even a completely different disk), you can choose which copy of Mac OS 9 you want the Classic application environment to run. Below this selection, you can choose to manually start or stop the Classic application environment. You can also restart, or even force the entire Classic application environment to quit, should the need arise.

Caution

Forcing the Classic application environment to quit is a drastic measure equivalent to pulling the power cord on a computer with Mac OS 9. You do not have an opportunity to save changes in open Classic documents. Before forcing Classic to quit, try clicking the Stop button in Classic Preferences. If that doesn’t stop Classic, switch to each open Classic application, and choose File Quit to quit the application. You should consider clicking Force Quit in Classic Preferences only after attempting to quit each open Classic application properly.

In the same panel, you can configure Classic to launch when you login, hide the startup screen from you, or warn you that Classic is about to start using the checkboxes to the right of the system selection.

A new addition to Mac OS 10.3 is the Show Classic status in menu bar checkbox. This great new feature places a Classic menu item in your menu bar at the top of the screen. From this menu, you can quickly see if Classic is running, start and stop the process, and even access the old Apple Menu Items folder from Mac OS 9, as shown in Figure 17-2. This menu also shows you the status of the Classic application environment at a glance: a light gray 9 means Classic is inactive, a dark 9 on a white background means Classic is sleeping, and a dark 9 with the left half of the square behind it colored black designates a fully active Classic. The icon also animates while Classic launches.

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Figure 17-2: The Classic preference pane allows you to control and set up the Classic application environment. In the top-right of the figure, note the new Classic status menu item.

Using the Advanced panel

The Advanced panel in the Classic preference panel allows you to further customize and troubleshoot the Classic application environment. Under Startup and Other Options, you can tell Classic to open the Extensions Manager (either automatically, or using a key combination) as Classic starts. However, it is important to remember that this setting applies only when you launch Classic from the Advanced panel of the Classic preference pane. At any other time, Classic loads normally, with the set of extensions you have preset in the Extensions Manager. For more on the Extensions Manager and how to control extensions, see the section “Extensions Manager control panel” later in this Chapter. Figure 17-3 shows the Advanced panel.

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Figure 17-3: The Advanced panel provides access to controls that let you troubleshoot Classic, as well as configure the amount of time before Classic sleeps.

Well-behaved Classic applications store their preferences in the Preferences folder of the System Folder. This is one place where the compartmentalization of ownership and individualized preferences can break down in Mac OS X. While Mac OS X is a true multiuser operating system, Mac OS 9 is not. Mac OS X allows you to create different Classic system preference folders for each user. In the Advanced panel, select Use Mac OS 9 preferences from your home. This creates new folders in your home folder, corresponding to the old Mac OS 9 Apple Menu Items, Favorites, Internet Search Sites, Launcher Items, Preferences, and the Startup and Shutdown Items (Disabled, too) in the folder of each user with the following path: ~/Library/Classic. The next time you launch Classic, it asks you if you want to copy the contents of the Mac OS 9 System Folder to the corresponding newly created folders as shown in Figure 17-4. Each user can then custom configure their Mac OS 9 preferences without getting in anyone else’s way.

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Figure 17-4: The first time you start the Classic application environment for a given user, you will be asked if you want to copy the contents of the Mac OS 9 Apple Menu Items, Favorites, Internet Search Sites, Launcher Items, Preferences, and the Startup and Shutdown Items to the user’s home folder.

For all intents and purposes, you are running an entirely separate operating system while Classic is running under Mac OS X. Therefore, even if you don’t have any running applications, Classic is using system resources. The Classic environment is using physical and virtual memory and even taking up processor cycles, just by being open. Although Mac OS X is much better at dividing your computer’s resources between applications than Mac OS 9 (because of preemptive multitasking), running the Classic environment can cause a performance hit. To maximize the use of your system resources, you can configure the Classic application environment to go to sleep after a period of inactivity. Rather than shutting Classic down, and having to restart it every time you need it, Mac OS X puts the Classic environment to sleep so that it uses minimal resources, yet can be woken up very quickly. To set the amount of time before Classic sleeps, when no applications are open, drag the slider at the bottom of the Advanced panel of the Classic System Preferences pane to the desired length of time.

Near the bottom of the Advanced panel, you see the Rebuild Desktop button. Within Mac OS 9, a volume’s desktop file contains the metadata (the descriptive information) of icons and document application bindings for that particular volume. Be prepared to become a professional progress bar watcher, because this option, although useful, can take quite some time to execute even with a limited amount of Mac OS 9 data on the specified volume. Rebuilding the desktop has no affect on Mac OS X, but can be helpful when you’re having problems with the Classic application environment.

Using the Memory/Versions panel

The Memory/Versions panel in Classic Preferences shows you detailed information about the applications running in the Classic application environment, as shown in Figure 17-5. This view gives you similar information to the About this Macintosh dialog from Mac OS 9. A major improvement over that view is the Show background processes option, which adds normally invisible system processes to the displayed list. This pane can be useful if you have several Classic applications running, because the Mac OS X’s Process Viewer application does not show individual Classic processes — only the whole environment. This information can help you determine how much memory each application is sucking up from your computer’s resources.

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Figure 17-5: The Memory/Versions panel of Classic Preferences, with the Show background applications option checked, allowing you to view the Classic support process.

The Classic startup process

On your computer, Mac OS X may be configured to start the Classic application environment automatically after login. If so, you see a gauge that measures the progress of the Classic application environment starting. This progress gauge appears in a window titled Classic is starting. This window may appear behind other windows because starting the Classic application environment does not monopolize the computer. While Classic starts, you can use the computer for other tasks. As soon as the Classic application environment starts, this progress window disappears. While the Classic application environment starts, you can expand the progress window by clicking the triangle on the left side of the window. The expanded progress window’s title also expands to reveal the names of the Classic system folder and the startup disk.

The expanded window also reveals that Mac OS 9 is in fact behind the Classic curtain. In the expanded window, you see the Mac OS 9 welcome message and a sequence of icons marching across the bottom of the window. These icons represent system extensions being loaded as Mac OS 9 gets under way. Clicking the triangle again collapses the window. You can stop Classic before it gets started by clicking the Stop button on the right of the Classic application environment starting window. Avoid forcing Classic to stop because doing so may lead to problems in the Classic application environment, much like unplugging your computer during startup. If you do click Stop, Mac OS X displays a warning and asks if you’re sure you want to stop Classic in the midst of starting. Click the Continue Startup button unless you are sure that you need Classic to stop. The Startup window is shown in Figure 17-6.

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Figure 17-6: The Classic application environment starting up, click the triangle under the progress bar to collapse the view.

Don’t be concerned if the Classic application environment does not start automatically after Mac OS X starts up. If the Classic environment hasn’t already been started, it automatically starts when it’s needed. When you launch a Classic application, the operating system knows that it can’t run this application without the Classic environment, so it starts the process for you.

Force quitting Classic applications

Sometimes a Classic application just stops behaving correctly or it locks up on you; in such a case, you can try to force quit the application. Force quitting a Classic application works the same way as force quitting a Mac OS X application, see Chapter 5 for detailed instructions on force quitting an application.

As noted in Chapter 1, the Classic application environment uses does not take advantage of Mac OS X’s protected memory and uses shared memory space. Apple very strongly recommends that you save any work in other Classic applications and restart the Classic application environment after force quitting a Classic application. See Figure 17-7 for an example of force quitting a Classic application.

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Figure 17-7: Because force quitting an application is a drastic measure, Apple asks you to confirm that this is your true intention.

Caution

Be aware that by choosing to force quit a Classic application, you run the risk of bringing the whole Classic application environment down with the single click.

You may remember reading earlier in the Chapter about force quitting the Classic application environment from the Classic preference pane. Choosing to force quit from the preference pane, will force the entire Classic application environment to quit, including all of your Classic applications with no chance to save any work. By using the Force Quit dialog, you can attempt to bring a single misbehaving application down, giving you the possibility of trying to save work in your other Classic applications before restarting the Classic application environment.

Cross Reference

See Chapters 21 and 24 for a few more ways that don’t require you to restart your computer in Mac OS 9 to delete stubborn files. In Chapter 21 you will find examples of applications that will help you delete stubborn files, and in Chapter 25 you find detailed instructions on how to delete files using the terminal application.

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Tips for Using the Classic Application Environment
  • While you can use the Advanced panel to rebuild the Classic Desktop, Apple recommends rebooting into Mac OS 9 (if your machine supports dual boot) and rebuilding the Desktop file by holding down the Command and Option keys during startup. (See Knowledge Base article 10182 for more information.)

  • The Classic application environment appears as TruBlueEnvironme in the Mac OS X Activity Monitor.

  • If a Classic application crashes, Apple recommends that you restart Classic to maintain the stability of the Classic application environment.

  • Often overlooked, another way to start the Classic application environment is to set a Classic application as a startup item. The launching of the Classic application in the startup item’s sequence triggers the start of the Classic application environment. You can add Classic applications to the startup item sequence by using the Startup Items panel of the Accounts preference pane in the System Preferences application.

  • Rebooting your computer into Mac OS 9 breaks the Mac OS X security model, because Mac OS 9 can’t see Mac OS X permissions to obey them. This is often suggested as a means to remove files that Mac OS X refuses to let you delete, but it is also considered a security issue.

  • Changes you make in control panels, the System Folder, preferences, and extensions while booted into Mac OS 9 affect the Classic application environment when you boot back into Mac OS X, and vice versa. The exception to this is if you have checked the home folders option in the Advanced panel of the Classic preference pane.

  • Apple recommends against installing and running Classic (or Mac OS 9 for that matter) on a UFS-formatted volume.

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Using Classic window controls

Windows in the Classic application environment have most of the same controls as the Aqua windows, but Classic window controls have different appearances and locations. Figure 17-8 shows examples of Classic window controls.

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Figure 17-8: Classic windows have many controls.

The Classic window controls have these effects:

  • Title bar: Drag to move the window. Double-clicking the title bar may collapse or expand the window the same as the collapse box described later.

  • Close box: Click to make the window go away. Pressing Option and clicking may close all windows in the same application.

  • Zoom box: Click to make the window as large as it needs to be to show all its contents, up to the size of the screen. (A zoomed window usually leaves a margin on the right side of the screen.) Click again to make the window resume its previous size and location.

  • Collapse box: Click to hide all but the window’s title bar, or if the window is collapsed, click to show the entire window. Pressing Option and clicking may collapse (or expand) all windows in the same application.

  • Scroll arrows, scroller, and scroll track: Click a scroll arrow to move the window’s contents a little; press an arrow to move smoothly; click the scroll track above or below the scroller to move in chunks; drag the scroller to bring another part of the window’s contents into view quickly. The scroll bar controls do not appear if scrolling would not bring anything else into view.

  • Resize control: Drag to adjust the size of the window.

  • Window frame: Drag to move the window.

As with Aqua windows, you won’t find all the window controls on every Classic window. Document windows have all or most of the available controls, movable dialogs have fewer controls, and immovable dialogs have no controls built into their borders.




Mac OS X Bible, Panther Edition
Mac OS X Bible, Panther Edition
ISBN: 0764543997
EAN: 2147483647
Year: 2003
Pages: 290

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