ScreenChooser V3.0

Online Documentation

Table of contents

    • An Introduction to ScreenChooser 
    • ScreenChooser is Shareware 
    • Some Legal Mumbo-Jumbo 
    • Installing ScreenChooser on your Macintosh 
        - Under System 7.0.x or better 
        - Under System 6.0.x 
        - A note about compression software 
    • The ScreenChooser Control Panel 
        - Under System 7.0.x or better 
        - Under System 6.0.x 
        - The General Layout 
        - Configuring ScreenChooser's Options 
            + General Options 
            + Startup Screen Options 
            + Backdrop Options 
        - Setting your Image Folder 
            + What formats can ScreenChooser support? 
            + Adding new file formats to ScreenChooser 
    • Tiling images with ScreenChooser 
    • Attaching sounds to images 
    • Using the ScreenChooser Goodies 
    • Common problems and solutions 
    • Explanations to some error messages 

An Introduction to ScreenChooser 

Are you tired of your Macintosh's boring desktop pattern? Have you ever wanted to replace the "Welcome to Macintosh" screen with something more exciting? If any of these statements apply to you, ScreenChooser is for you! 

ScreenChooser combines several desktop customization features into one package. Here is an overview of the things you can do with ScreenChooser (features new to version 3.0 are indicated): 

    • Startup Enhancements: 
        - At startup, display images in vivid colors. 
        - Have ScreenChooser choose images randomly or sequentially. NEW! 
        - Play sounds along with images. 
    • Desktop Enhancements: 
        - Replace the desktop pattern with a full color image. 
        - Dither images for optimum display on your monitor. 
        - Control the number of colors, or grays, used in the desktop image. NEW! 
        - Use true-color backdrops on Macs with thousands or millions of colors NEW! 
        - Change the desktop image on the fly, without rebooting. NEW! 
        - Have ScreenChooser change the desktop image *while* you work! NEW! 
    • Other Features: 
        - Slick, intuitive user interface. NEW! 
        - Context-sensitive help. 
        - Built-in documentation, with hypertext for easy browsing. NEW! 
        - External image loaders, for easy upgrades and expansion. NEW! 

Once you install ScreenChooser you will never be able to live without it! 

ScreenChooser is Shareware 

Before moving on, let us get the important stuff out of the way. ScreenChooser is distributed as Shareware. This means that it is not free, but rather, you are given the opportunity to try out ScreenChooser before you decide whether you want to buy it or not. After a month, should you decide that ScreenChooser is not for you, simply delete your copy of ScreenChooser and pay nothing. If, however, you decide to keep your copy of ScreenChooser (which we hope you will), pay only a small registration fee for your copy. Payment entitles you to upgrades, and most importantly, shows your willingness to keep Shareware alive and ensure the availability of more great Shareware software. The future of Shareware depends on users like you. We hope we can count on your support. 

Please take the time now to familiarize yourself with the details of registration by returning to the control panel and clicking the "Register" button. Complete information on registering ScreenChooser, as well as answers to some questions about registration, is provided there. 

One more thing before we move on, please be sure to read through the small disclaimer below. 

THIS PRODUCT IS PROVIDED "AS IS" AND THE AUTHOR MAKE NO WARRANTY, EXPRESS OR IMPLIED, WITH RESPECT TO THIS SOFTWARE, IT'S PERFORMANCE, MERCHANTABILITY, OR FITNESS FOR ANY PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR BE HELD LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES RESULTING FROM THE USE OR MISUSE OF THIS PRODUCT EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH. 

Installing ScreenChooser on your Macintosh 

ScreenChooser is designed to run under System 6.0.x or System 7.x. The installation procedure for either System version is provided below. 

Under System 7.0 or Better 

Under System 7.0, place the "ScreenChooser V3.0" control panel in the Control Panels folder. Place the "ScreenChooser Extras" folder inside the Extensions folder. The "ScreenChooser Extras" folder should not be renamed or placed anywhere else. More thoroughly, the installation should proceed as follows: 

    1. Drag the "ScreenChooser V3.0" Control Panel onto your System Folder icon. 
    2. Answer "Yes" when asked if ScreenChooser should go in the Control Panels folder. 
    3. Drag the folder "ScreenChooser Extras" into your Extensions folder. You should open your System Folder to find the Extensions folder. 
    4. Copy the files in the "ScreenChooser Goodies" folder, or the entire folder, to a readily available location, such as the Apple Menu Items folder or the desktop. 
    5. On your startup disk, designate a folder where you will keep ScreenChooser's image files. See Setting your Image Folder for more details. 

Under System 6.0.x 

Under System 6.0.x, place the "ScreenChooser V3.0" control panel file and the "ScreenChooser Extras" folder inside your System Folder. The "ScreenChooser Extras" folder should not be renamed. More thoroughly, the installation should proceed as follows: 

    1. Drag the "ScreenChooser V3.0" Control Panel into your System Folder. 
    2. Drag the "ScreenChooser Extras" folder into your System Folder 
    3. Copy the files in the "ScreenChooser Goodies" folder, or the entire folder, to a readily available location, such as the desktop. 
    4. On your startup disk, designate a folder where you will keep ScreenChooser's image files. See Setting your Image Folder for more details. 

A Note about Automated Compression Software 

If you are running DiskDoubler™, SpaceSaver™ or a similar program, you must either tell these utilities not to compress ScreenChooser's files or have the compression extension load before ScreenChooser. This is very important as ScreenChooser cannot read compressed files! Since extensions load in alphabetical order, you can force your compression extension to load first by preceding it's name with an "a". 

The ScreenChooser Control Panel 

Before use, ScreenChooser must be configured in the control panel. Basically, ScreenChooser consists of two portions: Behind the scenes runs a program, a little servant, if you will, that handles the bulk of the work — choosing the image for you, painting the desktop and so forth. This servant is eager to respond to your bidding, but it can only take orders issued through the control panel. With this in mind, let us explore ScreenChooser's control panel and the various options you can control. If you are reading this file from the control panel, skip to the section on the control panel's layout. 

Under System 7.0 or Better 

Under System 7.0, open your Control Panels folder and double-click the ScreenChooser icon. Find the Control Panels folder in the System Folder, or, select "Control Panels" from the Apple menu. Once you double-click the ScreenChooser icon, the ScreenChooser control panel will appear. 

Under System 6.0.x 

Under System 6.0, open the Control Panel desk accessory by choosing Control Panel from the Apple menu. Find the ScreenChooser icon, scrolling through the list of icons if necessary, and click on it to bring up the ScreenChooser control panel. 

The General Layout

The ScreenChooser control panel is divided into two major sections. The center-most configuration area, right below the title and resembling a little pad of paper, allows you to set most of ScreenChooser's options. Below the configuration area, three buttons allow you to choose your image folder, read the online help, and register your copy of ScreenChooser. The bottom-most "Quick Help" section displays information about items under the mouse pointer. 

Configuring ScreenChooser's Options

The centralconfiguration area, resembling a little pad of paper, displays one of three "pages" of options. Flip through the pages by clicking on the "dog-ears" at the lower-right corner of the configuration area. The pages are as follows: 

    • General Options - These options control ScreenChooser's general features. 
    • Startup Screen Options - These options let you specify how the images are chosen and shown at startup. 
    • Backdrop Options - Available only on color Macintoshes, this page lets you configure backdrop colors. 

General Options

On/Off Toggle Switch - Turns ScreenChooser on and off. 

Show Icon at Startup - If this option is checked, ScreenChooser will display its icon at startup. 

Enable Backdrops - If this option is checked, ScreenChooser will paint your desktop with the image it chose at startup. 

Change backdrop if idle xxx minutes - When this is option checked, ScreenChooser will choose a new image for your desktop whenever your Macintosh is left idle for the number of minutes you specify. This option has no effect if backdrops are disabled. 

Play Attached Sounds - If this option is checked, ScreenChooser will play sounds that are attached to the images. 

Startup Screen Options

[Display order:] Sequential - If this option is checked, ScreenChooser will select images sequentially. 

[Display order:] Random - If this is checked, ScreenChooser will select images in no particular order. 

Stretch Image to Entire Screen - This option tells ScreenChooser to stretch images to fit the entire screen. It has no effect on tilings. 

Maintain Image's Aspect Ratio - This option tells ScreenChooser to preserve an image's proportions. It has no effect on tilings or when stretching is disabled. 

Use Best Colors at Startup - When this option is checked, ScreenChooser will use the best possible colors when displaying an image. As a side effect, however, extension icons may appear tinted. 

Backdrop Options

The "Backdrop Options" page, pertaining only to color displays, is not shown on black and white systems. On a color Macintosh, use the "Backdrop Options" page to specify how you want color backdrops rendered. Choose between color and grayscale display of backdrops by selecting "Grays" or "Colors" from the toggle buttons and specify the maximum number of colors or grays from the scrollable list. If you decide to use "Thousands" or "Millions" of colors, you will not have the option to display the images in gray scale. 

The "Dither" option, available only available under System 7.0 or better, specifies whether ScreenChooser should dither the backdrop into the system's color palette. Dithering is recommended for improved color accuracy. 

Setting your Image Folder 

ScreenChooser can only do its job if you tell it which images to use. To do this, put your images files into a single folder on your start up disk. Then, open the control panel and click the "Choose Image Folder" button. Using the dialog box, select the folder in which you are keeping your images (System 6.0.x users should select an image within the folder). 

What formats can ScreenChooser support? 

ScreenChooser V3.0 supports image formats externally through image loader files. These loaders are kept in the "ScreenChooser Extras" folder. ScreenChooser comes with three image loaders, corresponding to the image formats supported internally by ScreenChooser V2.2: 

    • B&W StartUpScreen - Reads standard Black & White StartUp Screens 
    • MacPaint - Reads Black & White MacPaint files 
    • PICT File/PICT Resource - Reads color StartUp Screens, as well as standard PICT files. 

If you ScreenChooser cannot read an image in your image folder, make sure that the appropriate loader is in the "ScreenChooser Extras" folder. 

Adding new file formats to ScreenChooser 

ScreenChooser's external loaders allow you to add new image formats by putting the appropriate loader in the "ScreenChooser Extras" folder. Likewise, loaders can be updated to newer versions by replacing it's file. Registered users will be notified as other image loaders become available. 

Tiling images with ScreenChooser 

ScreenChooser can tile images over your entire desktop area, even across screen boundaries. You can have any image tiled by adding a ".tile" suffix to the image's file name. For example, to tile an image named "Placid River", rename the file "Placid River.tile". 

Attaching Sound Files to Images 

ScreenChooser can play sounds when displaying images or tilings, allowing you, for instance, to complement a scenic forest with the sounds of chirping birds. To attach a sound to an image file, enable the "Play Attached Sounds" option in the control panel and place a System 7.x or AIFF sounds files in the image folder, naming it like the associated image, but suffixing the name with ".snd". For example, to attach a sound to an image file named "Placid River", name the sound file "Placid River.snd". To attach a sound to a tiling, use the same naming convention, but append the ".snd" suffix to the ".tile" suffix. For example, to attach a sound file to "Placid River.tile", name the sound file "Placid River.tile.snd". 

ScreenChooser will also play any sound resources attached directly to the image file's resource fork. External ".snd" files override these sounds. Disabling the "Play Attached Sounds" option overrides all sounds. 

Using the ScreenChooser Goodies 

The ScreenChooser Goodies let you change the backdrop image on the fly. You will find two such applications in the "ScreenChooser Goodies" folder: 

    • Change Backdrop - Run this application to have ScreenChooser choose a new image for your desktop. ScreenChooser will use the selection method you specified in the control panel. 
    • Set Backdrop - Changes the backdrop to any image you specify. 

The ScreenChooser Goodies applications can be placed on anywhere on your hard disk. For easy access, System 7.x users might consider the Apple Menu Items folder or the desktop. System 6.0.x users might consider the desktop. These applications, however, will only run if ScreenChooser is installed and backdrops are active. 

Common problems and solutions 

Click on a problem to jump directly to it's solution. 

    1. Images appear bright and crisp at startup, but as a backdrop they appear fuzzy. 

Images appear bright and crisp at startup, but as a backdrop they appear fuzzy. 

If you have enabled "Use Best Colors at Startup", images will be displayed in glorious colors at startup. ScreenChooser achieves this effect by changing your monitor's color palette to one matching the image's dominant colors. However, ScreenChooser must reset the colors after startup since applications depend on the standard colors. For this reason, ScreenChooser cannot display backdrops in full colors on 256 color machines. If you Macintosh supports thousands or millions of colors, you can improve the backdrop's image quality by increasing the number of colors ScreenChooser uses to display backdrops. This can be done in the control panel's Backdrop Options page. 

Explanations to Some Common Error Messages 

The following errors are described in this section, click on a message to jump directly to it's description. 

    1. ScreenChooser can't create it's preferences file! 
    2. ScreenChooser can't find the image folder! 
    3. ScreenChooser does not know where you are keeping your images. 
    4. ScreenChooser can't find any images in your image folder. 
    5. ScreenChooser can't find any image loaders! 
    6. ScreenChooser does not know how to read "xxx"! 
    7. ScreenChooser does not have enough memory to read "xxx"! 
    8. ScreenChooser encountered an unexpected error while reading or displaying "xxx" 
    9. ScreenChooser can't find the file "xxx"! 
    10. ScreenChooser can't find a needed resource! 
    11. Don't forget to configure ScreenChooser in the control panel! 
    12. ScreenChooser is already running! 
    13. Insufficient memory for ScreenChooser to run! 

ScreenChooser can't create it's preferences file! 

ScreenChooser may be running off a locked disk. Unlock the disk to correct the problem. If the disk is not locked, the error might be caused by a damaged preferences file. Delete the ScreenChooser Preferences file and try again (under System 7.x, this file is in the "Preferences" folder in the System Folder. Under System 6.0.x, it is in the System Folder). 

ScreenChooser can't find the image folder! 

For some reason, ScreenChooser can no longer find your image folder (perhaps it was deleted). In the control panel, click on "Choose Image Folder" and select a new folder. 

ScreenChooser does not know where you are keeping your images. 

You have not configured you image folder. In the control panel, click on "Choose Image Folder" and select a folder. 

ScreenChooser can't find any images in your image folder. 

Your image folder is empty. Move some image files into your image folder and reboot. 

ScreenChooser can't find any image loaders! 

ScreenChooser uses external image loaders to read different image formats. You must put all your image loaders in the "ScreenChooser Extras" folder. Under System 7.x, the "ScreenChooser Extras" folder should be inside the "Extensions" folder. Under System 6.0.x, it should be in the System Folder. 

ScreenChooser does not know how to read "xxx"! 

ScreenChooser does not have a loader for that image type. Either remove the image file from the image folder or install the appropriate image loader. 

ScreenChooser does not have enough memory to read "xxx"! 

ScreenChooser tries to allocate enough memory to load every image file. If you get this error, try rebooting as sometimes it corrects the problem. If you continuously get the same error for the image file, it may be to large for ScreenChooser to handle. Remove the image file from the image folder. 

ScreenChooser encountered an unexpected error while reading or displaying "xxx" 

The image file might be damaged or of a format ScreenChooser cannot read. Remove the image from the image folder. 

ScreenChooser can't find the file "xxx"! 

The file has likely been moved or deleted. Rebooting will correct the problem. 

ScreenChooser can't find a needed resource! 

The ScreenChooser file is likely damaged. Replace it with a fresh copy. 

Don't forget to configure ScreenChooser in the control panel! 

ScreenChooser must be configured in the control panel before it can be used. 

ScreenChooser is already running! 

You have more than one copies of ScreenChooser installed. 

Insufficient memory for ScreenChooser to run! 

There is not enough memory to run ScreenChooser. Try reducing the number of colors you use in backdrops or try using smaller images. 

ScreenChooser ©1991-1995 Marcio Luis Teixeira