The canvas supports zooming and scrolling which is very helpfull when large diagrams are displayed. Elements in the canvas may be selected. Selected classes and nodes appear gray, selected generalization, associations and dependencies appear blue. The canvas provides context sensitive menus. Clicking with the right mouse button on a diagram element shows the context sensitive popup menu for this diagram element.
The canvas provides different modes, the navigation mode
and the layout mode.
There is always exactly one mode active and this active mode
defines the interaction between the user and the cancas.
Clicking the left mouse button on a package symbol sets the
content of this package as the new diagram.
Navigation Mode
The navigation mode makes it easy for the user to navigate
through the class diagrams at the different levels of the
package hierarchy.
Clicking the left mouse button on the background
moves one step up in the package hierarchy.
Dragging the left mouse button scrolls the content.
Layout Mode
The layout mode allows the user to modify the layout
of the diagram.
Selection
Clicking the left mouse button on a diagram element sets
this element as the current selection.
Clicking the left mouse button and simultaneously the shift button
on a diagram element sets
adds this element to the current selection.
Dragging the left mouse button opens a box.
All diagram elements which are inside this box are set
to the current selection.
Dragging the left mouse button and simultaneously pressing the
shift button opens a box.
All diagram elements which are inside this box are added
to the current selection.
Moving
Dragging the mouse when the pointer is over a selected element
moves this selection indirection of the mouse pointer.