GraphNode Drawlets Example

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GraphNode Drawlets Example

This really simple example shows a way to use Drawlets without a tool palette. We've simply added a new type of Figure called a GraphNode and had it take advantage of supplied LineConnectionHandle (in the shapes.lines kit) and TextEditHandle (in the text kit) to allow you to connect Nodes together and edit the text of the node. Then we made a simple subclass of the standard SelectionTool to override its double-click action. We made an instance of this tool the tool of our canvas (boring, standard background and foreground color), and this is the result:

Double click on the canvas to create a new node. Double clicking wherever there is not another figure will result in additional nodes.
Select a node by clicking on it (use Control and Shift keys to toggle or add to selections) or use box selection.
Drag from the LineConnectionHandle (in the middle of the node) to connect a line to another node.
Double click on a node to edit its text (rudimentary text editing for now). The first character will replace the existing text. Type to your heart's content, backspacing over mistakes. You will be editing the label until <Enter> is pressed (Shift-<Enter> gets you a new line, instead) or you click outside the label area.
And, of course, you can always copy/cut/paste/delete and move figures to the front or back using the appropriate keys (Ctrl-C/Ctrl-X/Ctrl-V/Delete or Backspace and Ctrl-F/Ctrl-B, respectively).

This demonstrates some of the flexibility you get from Drawlets. You don't have to use a tool palette, but you can. You decide the kind of handles you want on your figures. You decide whether you want to provide users with the ability to choose various DrawingStyle elements (color, font, etc.) in the manner you choose. You simply piece together the pieces that you want.

Notice that all of this was done without having to modify the framework. All of the other pieces only care that objects implement certain interfaces. We simply added our own type of figure and a special tool. The rest just worked!

Now how much would you pay?

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