How to make new tools
The best is to derive from existing tools, and redefine only what you don't like. The tools often function within a group of tools. They share a common way of using mouse buttons, and it is oke to push a tool unto the stack, and returning to the parent tool after stopping itself. Like tools based on a2dStTool use all as controller a2dStToolContr.
Changing State
A tool is used to manipulate what is in a drawing. User input combined with selected objects and mouse hit objects, brings a tool from one state into another.
|mouse event |key state | object hit |object selected| |LeftDown |Ctrl Down | true | 1 | |LeftDown + drag |Ctrl Down | true | 1 | |LeftDown + drag |Shift Down | true | 1 | |LeftDown + drag |Alt Down | true | 1 | |RightDown + drag |Ctrl Down | true | 1 | |LeftDown + LeftUp at xy |Alt Down | true | 1 |
Tool state
Zoom Tool
