The CDM palette provides eight tools.
The desired tool is selected by clicking the corresponding symbol in the palette; it is then highlighted, which specifies the current mode, and the shape of the mouse pointer changes accordingly.
The selected tool can then be used by clicking the work space on the desired location.
The Text tool is used to enter text on the work space (e.g. a title).
The Arrow tool (or selection mode) is the tool selected by default. It is active when no other tool is being used.
You can adopt it again at any moment by clicking with the right button of the mouse, which also ends the current operation mode.
It is used to select graphical objects in the design, and to move these objects or modify their size.
The Subtype entity, Entity and Relationship tools are used to design the corresponding objects. The creation is performed at the location clicked on the screen.
The Link tool is used to draw links between objects. The link is created when both of its ends are defined. The starting point corresponds to the first valid click, i.e. the first click on an object; all the previous invalid clicks are not taken into account. The final point is defined by a valid click, i.e. a click on an object compatible with the starting object.
All the rejected clicks are considered as intermediate points of the link. They correspond to clicks outside objects or to clicks on invalid objects: for example, two objects of the same type cannot be linked; also, a subtype entity can only be linked to a single entity. When each end is validated, the link will be drawn between the two objects linked, either directly by means of a single line, or by a broken line connecting all the intermediate points.
The link being created can be canceled by pressing the Esc key or by clicking with the right button of the mouse (which invalidates the link creation mode).
The Zoom In and Zoom Out tools maximize or minimize a part of the screen, zooms being centered around the location clicked.