Special Applet Attributes

There are six special attributes that can be used for customizing the applet window during downloading of an applet. (Note: The same applies to a JavaBeans component.) This section discusses:

Default Appearance

When none of these tags are used, the default appearance of the applet window is as follows:

The coffee cup logo is placed in the upper left corner. Its dimensions are 24x24 pixels and it is located 6 pixels from the top and left sides of the applet window. If the entire size of the applet is less than 36x36 pixels, then it will not be displayed. The status bar of the browser will display "Loading Java Applet ..." when the mouse points at the applet window.

Special Attributes

image

The image attribute allows you to replace the default coffee cup logo with a custom graphic. The format with the standard APPLET element is:

<APPLET ...>
<PARAM name="image" value="my_image.gif">
</APPLET>

See Using OBJECT, EMBED and APPLET Tags in Java Plug-in for how this would be mapped to the OBJECT or the EMBED tags.

If a custom graphic is specified, it should be the same size as the area of the applet window. If these sizes do not match, the graphic will be placed in the upper left corner of the area specified for applet. If it is larger than the applet window, part of it will get chopped off. If it is smaller than the applet window, gray, or whatever color is specified for boxbgcolor, will appear around it.

The image can be either a GIF or JPEG, and it should reside in the same directory where other resources for the applet reside; i.e., if the applet uses the codebase attribute, then this image should be in the codebase directory.

Note: The image file should not be in a packaged jar file with other applet resources, since the image needs to be displayed while downloading resources.

The status bar of the browser will display "Loading Java Applet ..." when the mouse is pointed at the applet window.

progressbar

With the progressbar attribute you can request display of a progress bar instead of the default graphic. The progress bar will horizontally fill the applet window up to 6 pixels to the right and left. The text "Loading Java Applet ..." will appear above the progress bar and be center-aligned with it. By default the progress bar is purple. The format for turning on the progress bar with the standard APPLET element is:

<APPLET ...>
<PARAM name="progressbar" value="true">
</APPLET>

The status bar of the browser will display "Loading Java Applet ..." when the mouse is pointed at the applet window.

boxmessage

With the boxmessage attribute you can customize the text that is displayed. If you use this attribute, the text will be used with the progress bar and with the status bar of the browser. The format for using this with the standard APPLET element is:

<APPLET ...>
<PARAM name="boxmessage" value="<your custom message goes here>">
</APPLET>

boxbgcolor, boxfgcolor, progresscolor

These attributes can be used to customize colors in the applet window.

By default the applet window background color is gray. The attribute boxbgcolor can be used to specify a different background color. The format for use with the standard APPLET element is:

<APPLET ...>
<PARAM name="boxbgcolor" value="<value>">
</APPLET>

where <value> may be:

Examples of each item above: value="cyan", value="111,222,145", value="silver", value="#33FF33"

By default the applet window foreground color is black. (The applet window foreground color is used for messages that appear in the window and for the border of the progress bar.) The attribute boxfgcolor can be used to specify a different foreground color. The color values are the same as described above. The format for use with the standard APPLET element is:

<APPLET ...>
<PARAM name="boxfgcolor" value="<value>">
</APPLET>

By default the progress bar fill color is purple. The attribute progresscolor can be used to specify a different fill color. The color values are the same as described above. The format for use with the standard APPLET element is:

<APPLET ...>
<PARAM name="progresscolor" value="<value>">
</APPLET>

Attribute Precedence

The order of precedence for these attributes is as follows:

1) If no parameters are provided, the default appearance described above is used.
2) If a custom graphic is specified via the image attribute, then the custom graphic will appear as described above under image.
3) If a progress bar is requested via the progressbar attribute, then the progress bar is displayed with the default text and color as described above under progressbar.
4) If custom text is provided via the boxmessage attribute, then the progress bar is displayed with the custom text as described above under boxmessage.

With any combination of image, progressbar, and boxmessage attributes, custom colors can always be provided via the boxbgcolor, boxfgcolor, and progresscolor attributes.

Failure Scenario

If an applet fails to load, the applet window will display error information. The applet window will have a single pixel border using the foreground color, and a small "broken" graphic will occupy the upper left corner. The user can right-mouse click over the applet window to get a popup menu with options to: