What is a GLG dial widget?
Like any other GLG widget, a GLG dial is a GLG drawing representing a dial with one or more rotating needles, a rotational axis with ticks and labels, and an optional label displaying the dial’s current value. The objects in the dial’s drawing are wired up using the GLG dynamics and constraints to implement a dial widget. Two versions of dials are provided: • A “heavy-weight” version uses a viewport object as a drawing surface and can handle user interaction. The GlgKnob interaction handler is attached to the dial’s viewport to handle user interaction, allowing the user to move the dial’s needle with the mouse. The interaction handler may be disabled for the output-only operation. • A “light-weight” viewportless version does not use a viewport object as a background and may be used in dashboards as a non-rectangular dial on top of a custom image background. The light-weight dials do not support user interaction and may be used only for output as a part of a bigger dashboard drawing. Th
