DataHubListener

DataHubListener — a base class for all applets that send and receive data.

Description

DataHubListener is a base class for all applets that send and receive data with a DataHubBaseApplet. You should never instantiate a DataHubListener directly. This is the class that you would likely derive from when creating a custom applet for use with the DataHub.

Base Class

Applet

Parameters

ParameterTypeDefaultDescription
borderstringnullOne of two options: 1) "style;depth;highlight;shadow", where style is one of: bevel or etch, depth is one of: lowered or raised and highlight and shadow are colors; or 2) "line;color;thickness".
marginsstring"0;0;0;0"The number of pixels determining the empty space between the outside border and the content of the applet. The order is: top;left;bottom;right.
fontFontnullThe font for the displayed characters. Font is specified as: fontname;bold|italic|normal;pointsize where bold|italic|normal means any of these, separated by the | character
valignstringnullThe vertical alignment of the applet in the space provided. One of "center", "top", or "bottom".
halignstringnullThe horizontal alignment of the applet in the space provided. One of "center", "left", or "right".
enabledbooleantrueEnables or disables the Java component within the applet. For example, if you disable a scroll bar, it will no longer respond to the mouse.
parentstringnullThe same as the name parameter of the applet derived from DataHubBaseApplet on this web page.
pointsstringnullA list of unqualified (i.e., without domain: prepended to them) data point names, separated by spaces. This parameter is used when the applet will service more than one data point.
pointstringnullIf the points parameter is null, then this parameter will contain a single point name specifying the data point that this applet will service.
fgcolorcolorBLACKThe foreground color of this applet.
bgcolorcolorWHITEThe background color of this applet.
opaquebooleanfalseAn optimization flag. If you specify that the applet is opaque, the redrawing functions in the Java engine can safely clip any windows behind this applet. If the applet contains a transparent or translucent background, then it is not opaque. In that case, setting the applet to opaque will cause drawing errors.
bgmodestring [scale, center, tile]scaleA string specifying the tiling mode for the background image (scale, center, or tile).
formatstringnullFor applets that display point values as text, this specifies the format to be used. The format must be in the form expected by the Java class DecimalFormat.
bgimagestringnullA URL specifying a background image to display behind the table cells.
bgalphastring1.0A string specifying the alpha blending value (0.0 - 1.0). Where 0 is transparent (invisible) and 1.0 is opaque. Numbers between 0 and 1 indicate degrees of translucency.