Drag and Drop

The application programming interface has a drag and drop feature for better support of user interaction. After the drag and drop mode has been entered, an application program connected to uDraw(Graph) is informed about the following events issued by moving the mouse while holding the middle mouse button.

The user creates a new edge (i.e. connects two existing nodes) by dragging from one node and releasing the mouse button on another node.
The user creates a new child node by dragging a new edge from one node and releasing the mouse button on empty space.
The user creates a new node by clicking on empty space.

For all these events, there are special answers sent by the API. The application connected to the API has to evaluate the answers and react in an appropriate manner to create the new nodes and/or edges related to the drag and drop operation. Please refer to API command category Drag and Drop for technical information. Using drag and drop in the graph editor is explained in the tutorial.

You can test the drag and drop feature by using the graph editor example application contained in the uDraw(Graph) distribution. Please follow the steps in the graph editor tutorial for details using drag and drop.

Back to concept overview.