Types of Draggers

For all draggers subclassed from SoDragger, the user employs a click-drag-release motion with the mouse. Uses of Draggers indicates the use of each dragger subclassed from SoDragger. For example, the drag-point dragger responds to dragging by translating in three dimensions.

Subclasses of SoDragger fall into two general categories: simple draggers and compound draggers. In general, simple draggers perform only one operation, such as a scale or a translation. Compound draggers perform several operations and are composed of multiple simple draggers. Simple draggers can be used in three ways:

• You can connect the field of a simple dragger to other fields or to engines in the scene graph. This is a simple way to set up dependencies within the scene graph.
• You can write callback functions that are performed when interaction starts or finishes, whenever the mouse moves, or when the value in the dragger's field changes.
• You can use the simple draggers as building blocks to create more complex draggers. Compound draggers are similar to simple draggers, except that they have more parts because they are comprised of two or more draggers. The SoTransformBoxDragger, for example, uses a scale dragger, three rotators, and six translators.

Dragger Classes

Uses of Draggers

Dragger	Use
SoCenterballDragger	rotation, center
SoDirectionalLightDragger	rotation
SoDragPointDragger	translation
SoHandleBoxDragger	translation, scale
SoJackDragger	rotation, translation, uniform scale (three dimensions)
SoPointLightDragger	translation
SoRotateCylindricalDragger	rotation
SoRotateDiscDragger	rotation
SoRotateSphericalDragger	rotation
SoScale1Dragger	scale (one dimension)
SoScale2Dragger	scale (two dimensions)
SoScaleUniformDragger	uniform scale (three dimensions)
SoScale2UniformDragger	uniform scale (two dimensions)
SoSpotLightDragger	translation, rotation, cone angle
SoTabBoxDragger	scale, translation
SoTabPlaneDragger	scale (two dimensions), translation (two dimensions)
SoTrackballDragger	rotation, scale
SoTransformBoxDragger	rotation, translation, scale
SoTranslate1Dragger	translation (one dimension)
SoTranslate2Dragger	translation (two dimensions)