A ModalTool is a tool which "takes control" of operation. An example is the zoom tool. If the
zoom tool is "on" then other tools modal tools must be off.
Must have a public default constructor so that the plugin frame work can instantiate the class.
Contains the following properties:
ToolConstants.DEFAULT_CURSOR_ID_KEY - the cursor ID value from "toolCursorId"
attribute of "modalTool" extension
Called when tool button is pressed. If active is set to true the tool is Registered with the
source Component so that it receives events and will begin operating If active is set to
false the tool is set as inactive and deregistered with the component.
Parameters: active - if true the tool is Registered with the source Component so that it receivesevents and will begin operating. if false the tool is set as inactive and deregisteredwith the component.
Sets the current cursor ID for the modal tool. If it is needed
the actual updating of the mouse cursor is performed automatically.
Parameters: id - the cursor ID from net.refractions.udig.project.ui.tool.toolCursorextension or the constant from ModalTool interface.