vtkBalloonRepresentation

Section: Visualization Toolkit Widget Classes

Usage

The vtkBalloonRepresentation is used to represent the vtkBalloonWidget. This representation is defined by two items: a text string and an image. At least one of these two items must be defined, but it is allowable to specify both, or just an image or just text. If both the text and image are specified, then methods are available for positioning the text and image with respect to each other.

The balloon representation consists of three parts: text, a rectangular frame behind the text, and an image placed next to the frame and sized to match the frame.

The size of the balloon is ultimately controlled by the text properties (i.e., font size). This representation uses a layout policy as follows. If there is just text and no image, then the text properties and padding are used to control the size of the balloon.

If there is just an image and no text, then the ImageSize[2] member is used to control the image size. (The image will fit into this rectangle, but will not necessarily fill the whole rectangle, i.e., the image is not stretched).

If there is text and an image, the following approach ia used. First, based on the font size and other related properties (e.g., padding), determine the size of the frame. Second, depending on the layout of the image and text frame, control the size of the neighboring image (since the frame and image share a common edge). However, if this results in an image that is smaller than ImageSize[2], then the image size will be set to ImageSize[2] and the frame will be adjusted accordingly. The text is always placed in the center of the frame if the frame is resized.

To create an instance of class vtkBalloonRepresentation, simply invoke its constructor as follows

  obj = vtkBalloonRepresentation

Methods

The class vtkBalloonRepresentation has several methods that can be used. They are listed below. Note that the documentation is translated automatically from the VTK sources, and may not be completely intelligible. When in doubt, consult the VTK website. In the methods listed below, obj is an instance of the vtkBalloonRepresentation class.