Modes of operation for Check Box and Radio Button objects

The Check Box and Radio Button objects both have two modes of operation: Normal and Tri-State.

The modes work in essentially the same way for each object.

Normal Mode

Normal mode is, as the name implies, the normal mode of operation for the object. In this mode, the object has two possible states: FALSE (not selected) and TRUE (selected).

Table 1. Appearance of objects in Normal mode
Object State	Check Box		Radio Button
Object State	Plain	Push Like	Plain	Push Like
FALSE
TRUE

When the user clicks/selects the object during runtime — that is, when the object state is set to TRUE — the value of the project tag configured in the Tag field of the object properties is set to equal the value configured in the True Value field.

When the user deselects or clears the object — that is, when the object state is reset to FALSE — the value of the tag configured in the Tag field is set to NOT the value configured in the True Value field. In most cases that means it is set to 0 or an empty string, but there are two exceptions:

If the True Value field is configured to equal 0, then NOT that value is 1.
If the True Value field is left completely blank, then NOT that value is the string UNSELECTED.

Tri-State Mode

Tri-State mode is enabled by selecting the Tri-State option in the object's Object Properties dialog. This adds a third possible state to the object.

Table 2. Appearance of objects in Tri-State mode
Object State	Check Box		Radio Button
Object State	Plain	Push Like	Plain	Push Like
FALSE
TRUE
TRI-STATE

Clicking/selecting the object the first time works the same as it does in Normal mode.

When the user clicks/selects the object a second time, the object state is set from TRUE to TRI-STATE and the value of the tag configured in the Tag field of the object properties is set to equal the value configured in the Tri-State field.

When the user click/selects the object a third time, the way the object changes depends on which type of object it is:

The Check Box object is reset from TRI-STATE to FALSE, and the value of the tag configured in the Tag field is set to NOT the value configured in the True Value field. This is similar to how it works in Normal mode.
The Radio Button object is set from TRI-STATE back to TRUE, and the value of the tag configured in the Tag field is set to equal the value configured in the True Value field. If the user keeps clicking on the object, then the object will simply toggle between TRUE and TRI-STATE. To actually clear the object — that is, to reset the object back to FALSE — the user must click/select another Radio Button object in the same group.

This functionality is summarized in the following table:

Current State of Object	How Object Changes When Clicked
Current State of Object	Check Box	Radio Button
FALSE	Object state set to TRUE and value set to equal True Value
TRUE	Object state set to TRI-STATE and value set to equal Tri-State
TRI-STATE	Object state set to FALSE and value set to NOT True Value	Object state set to TRUE and value set to equal True Value

Note: If reseting the object to FALSE would give the tag configured in the Tag field the same value as if the object was set to TRI-STATE — that is, if NOT True Value is equal to Tri-State — then the tag will instead be set to the minimum unsigned integer different from True Value.

For example, if True Value equals 1 and Tri-State equals 0, then when the object is reset to FALSE, the tag configured in the Tag field will be set to 2. If True Value equals -4 and Tri-State equals 0, then when the object is reset to FALSE, the tag configured in the Tag field will be set to 3.