Code Overview - winder/Universal-G-Code-Sender GitHub Wiki

Overview

Universal G-Code Sender has three layers: GUI, controller, and communicator. The GUI is a visual representation of the CNC machine and contains a controller object which it uses to control the machine. The controller object contains a communicator object which it uses for sending data to the CNC firmware. The controller is also responsible for encapsulating commands for the communication layer and interpreting responses, then re-encapsulating results for return to the GUI. Finally the communication layer is responsible for maintaining a connection with the CNC machine and transmitting/retrieving data.

API Headers

These layers communicate from top to bottom by implementing a set of API interfaces, see IController.java and ICommunicator for those APIs. From the bottom back up to the top an object listener API is used, for that refer to CommunicationListener.java and ControllerListener.java which define the status messages returned from the lower level classes.

Top-to-bottom communication

An example of top to bottom communication can be seen in the code to send a command to GRBL:

GrblController controller = new GrblController();
controller.openCommPort(port, portRate);
controller.queueStringForComm("G0 X20 Y15 Z0");

openCommPort and queueStringForComm are defined in the controller API, so if another firmware were to be implemented (such as TinyG) a new class named TinyGController could be created and will work exactly the same.

Bottom-to-top communication

An example of bottom to top communication can be seen in the code which listens for console style messages from the controller class:

controller.addListener(this);

 ...

public void messageForConsole(String msg, Boolean verbose) {
    if (verbose == false || this.showVerboseMessages == true) {
        this.consoleTextArea.append((verbose ? "[verbose]" : "") + msg);
    }
}

In this manner any firmware can implement the same listener API and communicate back to the GUI. This is exactly how the visualizer window works. The new window is added as a listener to the controller object and it automatically gets the same status messages as the main GUI window without adding any dependencies.

A connection between the control layer and the communication layer is done in exactly the same way, thus if a new serial library were to be implemented it could be swapped in without effecting the control layer.