ExtPlane-Plugin Java Interface

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A java library to communicate to ExtPlane-Plugin so it can be used to write java software that make use of X-Plane DataRefs.

License

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GNU GPLv3

Copyright (C) 2015 Pau G.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Build

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To build the jar you will need Maven (https://maven.apache.org/).

Download the project, move to the pom.xml folder and run "mvn package".

How to use

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Requisites

• Install ExtPlane-Plugin in your X-Plane.
• Before start using the interface you have to run your X-Plane.

Starting the service

The main entrance to the interface is at org.cutre.soft.ExtPlaneInterface. Instantiate the interface passing the XPlane IP and the port 51000.

ExtPlaneInterface iface = new ExtPlaneInterface("localhost", 51000);
iface.start();

Calling start() will connect to ExtPlane-Plugin and will get ready to receive DataRefs.

Subscribing to DataRefs

ExtPlane-Plugin requires to subscribe dataRefs to receive their data. So, you have to say to ExtPlane-Plugin what dataRefs have to send.

// Include dataRefName with standard accuracy
iface.includeDataRef(dataRefName);

// Include dataRefName with custom accuracy
iface.includeDataRef(dataRefName,1000.0F);

With accuracy you can decide how much the dataref's value can change before a update is sent. Set it to as large value as possible to maximize frame rate and minimize network traffic.

To stop getting a dataRef just call,

iface.excludeDataRef(dataRefName);

Getting DataRefs

Once connected to ExtPlane-Plugin and having subscribed to one or more dataRefs, it's time to get their values.

To get dataRefs you may,

• Get DataRef value by calling,

iface.getDataRefValue(dataRefName)

This will return a String array with the dataRef value. To get dataRef data type's, call

iface.getDataRefType(dataRefName)

This will return a DataRefType enum with the right data type,

public static enum DataType {
    ArrayFloat,
    ArrayInt,
    Base64,
    Double,
    Float,
    Int
}

• Get dataRef object by calling,

iface.getDataRef(dataRefName)

This will return a DataRef object.

• Get DataRef object implementing an org.cutre.soft.util.Observer object,

Observer<DataRef> s = new Observer<DataRef>() {
   public void update(DataRef object) {
      System.out.println(object);
   }
};

iface.observeDataRef(dataRefName, s);

Every time we get a new dataRefName value from the sim we will call the update method. To stop receiving updates just call,

iface.unObserveDataRef(dataRefName, s);

Setting DataRefs value

It is possible to set a new value to a DataRef calling,

iface.setDataRefValue(altimeterSettingDataRefName, "30.0");
iface.setDataRefValue(engintThrottleDataRefName, new String[] {"1.0", "1.0", "1.0", "1.0", "1.0", "1.0", "1.0", "1.0"});

Sending messages

Setting dataRef values, pressing a button or a key are messages send to ExtPlane-Plugin.

• org.cutre.soft.epi.command.ButtonCommand: allow pushing/releasing a sim button (joystick),

// Push a button
iface.sendMessage(new ButtonCommand(ButtonCommand.ButtonAction.PRESS, buttonId));

// Release a button
iface.sendMessage(new ButtonCommand(ButtonCommand.ButtonAction.RELEASE, buttonId));

• org.cutre.soft.epi.command.DataRefCommand: allows sending a DataRef message to the plug-in,

// Subscribe to a dataRef
iface.sendMessage(new DataRefCommand(DataRefCommand.DATAREF_ACTION.SUBSCRIBE,dataRefName));

// Sets a dataRef value
iface.sendMessage(new DataRefCommand(DataRefCommand.DATAREF_ACTION.SET, dataRefName, value)) 

// Unsubscribe a dataRef
iface.sendMessage(new DataRefCommand(DataRefCommand.DATAREF_ACTION.UNSUBSCRIBE,dataRefName));

• org.cutre.soft.epi.command.ExtPlaneCommand: send an ExtPlane-Plugin config command,

// Press a key
iface.sendMessage(new ExtPlaneCommand(ExtPlaneCommand.EXTPLANE_SETTING.UPDATE_INTERVAL, interval));

• org.cutre.soft.epi.command.KeyCommand: send a key press to the sim,

// Press a key
iface.sendMessage(new KeyCommand(keyId));

• org.cutre.soft.epi.command.CmdCommand: send a command to X-Plane via ExtPlane-Plugin,

// create a new CmdCommand that sets the autopilot on
CmdCommand myMessage = new CmdCommand(CmdCommand.SUBCOMMAND.ONCE, "sim/autopilot/servos_on");
iface.sendMessage(myMessage);

List of key and button id's can be found at: http://www.xsquawkbox.net/xpsdk/mediawiki/XPLMUtilities Note that the key and button id's are numbers, not names. X-Plane does not provide a way to lookup keys or buttons by name. More recently, XPlane Command Management evolved : see [https://developer.x-plane.com/sdk/XPLMUtilities/#X-PLANE_COMMAND_MANAGEMENT].

You can also find two files containing all the datarefs and all the commands in your X-Plane installation directory : look at Commands.txt and DataRefs.txt in XP installation directory/Resources/plugins/ folder.