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Button

The Button object defines a button intended mainly for VTs with touchscreens or pointing devices, but it must also be supported by all VTs. If no touchscreen or pointing device is supported, the VT must provide a way to navigate to this object. When the Button object is activated, the VT sends a Button Activation message to the Working Set Master.

Attributes

AID
Attribute
Description
Object Id

Unique identifier of the object. This must be unique within the object pool (2 bytes, 0-65534).

Type

The type of the object.

Width

Width of the object in pixels.

Height

Height of the object in pixels.

Background Colour

Background colour. A colour based on the index of the Colour Palette.

Border Colour

Border colour.

Key code

The VT reports this code in the Soft Key Activation message.

NOTE: Key code zero (0) is reserved for the ACK function.

Options (Button)

Option bits of the Button.

  • Bit 0 = Latchable: If TRUE, the Button remains in the pressed state after being pressed until it is pressed again. If FALSE, the Button functions as a momentary button. This value cannot be changed at runtime by a “Change Attribute” command. Changes to this bit are ignored by the VT.
  • Bit 1 = Current state of a latchable Button:
    0 = Released,
    1 = Latched
    This property is ignored for momentary buttons.
  • Bit 2 = Suppress border: If FALSE, the VT draws the default border. If TRUE, no border is drawn (neither in momentary nor in latch mode), and the area normally reserved for the border remains empty.
    • Number of Objects to follow

    Number of following objects, even if the value is zero. Each of these objects is contained in this Alarm Mask. Each object consists of 6 bytes: two (2) for the Object ID and four (4) for the position.

    Number of Macros to follow

    Number of contained macro references, even if it is zero.

    Each macro reference consists of 2 bytes: one for the event Id and one for the macro Id.

    When the specified event occurs, the associated macro is executed. VT version 5 and later: A reference to a macro with a 16-bit Object Id counts as 2 macro references in the context of this attribute.