Radio Button Widget (RadioButton.class)

A Radio Button is a labeled, round button used to make a single selection from several options. To set a radio button, click on either the button or the adjacent label. All radio buttons that have the same groupName are considered part of a radio button group. Only one radio button within a group can be set at any one time. When a radio button is selected, its function(s) are called with the argument being the intrinsic value of the radio button. Each radio button can invoke its own href function (or set of functions).

When using initHref to determine the initialCondition of the radio button group, the value of the data returned from the initHref function must match the internalNumber of one of the radio buttons in the group. If the internalNumber is not specified, the first radio button found in the html file will be assigned internal number 1, with the internal numbers incrementing with each subsequent radio button found in the html which is part of the same radio button groupName.

Radio Button Parameter Attributes:

Parameter="invisible" value="CHECKED" or "UNCHECKED" — Specifies if the Radio Button is to start out invisible or not. If the attribute is not checked, then by default the radio button is visible. If the Radio Button starts out invisible, the only way to make it visible again is via the IWC method reappear().

Parameter="buttonAlign" value="LEFT" or "RIGHT" — Specifies the location of the radio button in relation to the label text.

Parameter="font" value="font" — Specifies the font and font size used for the radio button label. See Amulet GEM Font Converter for more information regarding the creation of .auf font files. Default is Bitstream Vera Sans. The default font size for the radio button label is 12pt.

Parameter="fontColor" value= See color entry conventions — Specifies the font color used for the radio button label. See section on colors for more information. If no font color is specified, the default color is black.

Parameter="fontStyle" value="BOLD" or "ITALIC" or "PLAIN" — Specifies the style associated with the radio button label font. The available font styles are:

• BOLD — The option text is bold. (i.e. text)
• ITALIC — The option text is italicized. (i.e. text)
• PLAIN — The option text is the standard font. (i.e. text)

Parameter="groupName" value="text" — Specifies the radio button group this radio button is a part of.

Parameter="href" value="function(s)" — The function (or multiple/sequenced functions) invoked when a radio button is set. Unlike checkboxes, radio buttons within a group can call different href function(s). See Appendix B for all available functions for the Radio Button widget.

Parameter="initialCondition" value="ON" or "OFF" or "FromInitHref" — Specifies the initial condition of the radio button when the page is loaded. If "FromInitHref" is selected, the function specified by the InitHref attribute is called. The returned byte value determines which single button (if any) within the group is selected; the returned value must exactly match one of the button's internalNumber.

Parameter="label" value="text" — Specifies the name that appears to the right or left of the radio button.

Parameter="cacheImage" value="CHECKED" or "UNCHECKED" — A checkbox that specifies to GEMstudio to store this image in the SDRAM in an uncompressed format for immediate use. Since the image is written to the SDRAM only once per project, it is not suitable for images that contain transparencies. (Images can be either .GIF, .JPG, or .PNG.)

Optional Radio Button Parameter Attributes:

Parameter="emptyImage" value="image" — Specifies the image to use when the radio button is in the not set state. If this attribute is not present, then a default image, the Amulet logo, is used.

Parameter="fullImage" value="image" — Specifies the image to use when the radio button is in the set state. If this attribute is not present, then a default image, the Amulet logo, is used.

Parameter="hrefOnHitOnly" value="CHECKED" or "UNCHECKED" — Specifies if the radio button href function(s) is launched only upon a "hit" or not. By default, hrefOnHitOnly is UNCHECKED, which means if the radio button has an initHref function, the href of the radio button which starts out "on" is launched upon loading the page. The href is also launched after a forceUpdate() call. By setting hrefOnHitOnly to CHECKED, the href will only be launched upon the radio button physically being selected or upon a forceHit() call.

Parameter="initHref" value="function" — Specifies the function called when the page is loaded. Use this attribute whenever FromInitHref is used as the initialCondition. All radio buttons within a group must have the same initHref function. The value of the data returned from the initHref function must match the internalNumber of one of the radio buttons in the group. If there is See Appendix B for all available functions.

Parameter="internalNumber" value="number" — Specifies the internal number of the radio button, used by the OS to determine which radio button is on. Should only be used if using initHref. Each button within a radio button group must have a unique internal number. If the value of the data returned from the initHref function matches the internalNumber of the radio button, then that radio button starts out in the "on" position. If the internalNumber is not specified, the first radio button found in the html file will be assigned internal number 1, with the internal numbers incrementing with each subsequent radio button found in the html which is part of the same radio button group.

Parameter="noSdram" value="CHECKED" or "UNCHECKED" — Specifies if the background of the Radio Button and the three images are to be stored in SDRAM or not. If noSdram=CHECKED, then applying the disappear() IWC method could result in strange behavior. If the parameter is UNCHECKED, the button widget will allocate space in the SDRAM equivalent to the size of the Radio Button times four within the frame buffer. UNCHECKED is the default.

Parameter="trackingImage" value="image" — Specifies the image to use when the radio button is in the pen down state. If this attribute is not present, then a default image, trackingImage.gif, located in Amulet/Color/Configuration/Widgets/RadioButton/, is used.