When i enable virtual stick control and tries to update the control values using Virtual stick control it updates values but remote controller get disabled (Unable to send data without Virtual stick mode enabled ).Both virtual stick and remote controller commands not get transmitted .
As noted above, enabling virtual stick will disable direct stick control but you can "simulate" stick control using the hardwareStatus. HardwareStatus returns the position of each stick as the user moves it and the information is reported to the app.
Using the above method you could coordinate your app's use of virtual stick with the user's movement of the physical sticks and send virtual stick commands that include the user's controls.
This is expected behavior. They are mutually exclusive. When you want to control aircraft through virtual sticks the remote controller sticks are disabled. But if you want to take control of aircraft change the mode of remotecontroller
This is a design decision by DJI (a very dangerous one in my opinion).
Note that this does not mean the user will always be able to use RC
sticks to control the aircraft; for example, in F mode (P mode for
A3/N3 FW > 1.5.0.0) the sticks are unavailable when the SDK is
executing movement control. The correct way to assert the RC's control
precedence is to make sure the above conditions for API control are
unmet - usually the easiest way to do so is to switch the RC out of F
mode into P or A mode. For A3/N3 FW > 1.5.0.0, please see mode switch
changes.
http://developer.dji.com/onboard-sdk/documentation/introduction/things-to-know.html
I solved that toggling virtual sticks on/off when send FlightControlData:
private void toggleVirtualStick(boolean b, String s) {
getAircraftInstance().getFlightController().setVirtualStickModeEnabled(b, new CommonCallbacks.CompletionCallback() {
#Override
public void onResult(DJIError djiError) {
if (djiError == null) {
((Switch)findViewById(R.id.virtualStick)).setChecked(b);
} else {
showToast(djiError.getErrorCode() + " - " + djiError.getDescription());
}
}
})
Related
I have started to implement a set of classes that provide a direct interface to MongoDB for persistence, similar in spirit to the now-unmaintained SDB persistor implementation for RDBMS.
I am using the time-honored technique of creating the necessary concrete classes from the interfaces and doing a println in each method, therein allowing me to trace the execution. I have gotten all the way to where the engine is calling out to my cursor set up:
public ExtendedIterator<Triple> find(Node s, Node p, Node o) {
System.out.println("+++ MongoGraph:extenditer:find(" + s + p + o + ")");
// TBD Need to turn s,p,o into a match expression! Easy!
MongoCursor cur = this.coll.find().iterator();
ExtendedIterator<Triple> curs = new JenaMongoCursorIterator(cur);
return curs;
}
Sadly, when I later call this:
while(rs.hasNext()) {
QuerySolution soln = rs.nextSolution() ;
System.out.println(soln);
}
It turns out rs.hasNext() is always false even though material is present in the MongoCursor (I can debug-print it in the find() method). Also, the trace print in the next() function in my concrete iterator JenaMongoCursorIterator (which extends NiceIterator which I believe is OK) is never hit. In short, the basic setup seems good but then the engine never cranks the iterator on find()
Trying to use SDB as a guide is completely overwhelming for someone not intimately familiar with the software architecture. It's fully factored and filled with interfaces and factories and although that is excellent, it is difficult to nav.
Has anyone tried to create their own persistor implementation and if so, what are the basic steps to getting a "hello world" running? Hello World in this case is ANY implementation, non-optimized, that can call next() on something to produce a Triple.
TLDR: It is now working.
I was coding too eagerly and JenaMongoCursorIterator contained a method hasNexl which of course did not override hasNext (with a t ) in the default implementation of NiceIterator which returns false.
This is the sort of problem that eclipse and visual debugging and tracing makes a lot easier to resolve than regular jdb. jdb is fine if you know the software architecture pretty well but if you don't, the multiple open source files and being able to mouse over vars and such provides a tremendous boost in the amount of context that can be created to home in on the problem.
Apache Beam has recently introduced state cells, through StateSpec and the #StateId annotation, with partial support in Apache Flink and Google Cloud Dataflow.
I cannot find any documentation on what happens when this is used with a GlobalWindow. In particular, is there a way to have a "state garbage collection" mechanism to get rid of states for keys that have not been seen for a while according to some configuration, while still maintaining a single all-time state for keys are that seen frequently enough?
Or, is the amount of state used in this case going to diverge, with no way to ever reclaim state corresponding to keys that have not been seen in a while?
I am also interested in whether a potential solution would be supported in either Apache Flink or Google Cloud Dataflow.
Flink and direct runners seem to have some code for "state GC" but I am not really sure what it does and whether it is relevant when using a global window.
State can be automatically garbage collected by a Beam runner at some point after a window expires - when the input watermark exceeds the end of the window by the allowed lateness, so all further input is droppable. The exact details depend on the runner.
As you correctly determined, the Global window may never expire. Then this automatic collection of state will not be invoked. For bounded data, including drain scenarios, it actually will expire, but for a perpetual unbounded data source it will not.
If you are doing stateful processing on such data in the Global window you can use user-defined timers (used through #TimerId, #OnTimer, and TimerSpec - I haven't blogged about these yet) to clear state after some timeout of your choosing. If the state represents an aggregation of some sort, then you'll want a timer anyhow to make sure your data is not stranded in state.
Here is a quick example of their use:
new DoFn<Foo, Baz>() {
private static final String MY_TIMER = "my-timer";
private static final String MY_STATE = "my-state";
#StateId(MY_STATE)
private final StateSpec<ValueState<Bizzle>> =
StateSpec.value(Bizzle.coder());
#TimerId(MY_TIMER)
private final TimerSpec myTimer =
TimerSpecs.timer(TimeDomain.EVENT_TIME);
#ProcessElement
public void process(
ProcessContext c,
#StateId(MY_STATE) ValueState<Bizzle> bizzleState,
#TimerId(MY_TIMER) Timer myTimer) {
bizzleState.write(...);
myTimer.setForNowPlus(...);
}
#OnTimer(MY_TIMER)
public void onMyTimer(
OnTimerContext context,
#StateId(MY_STATE) ValueState<Bizzle> bizzleState) {
context.output(... bizzleState.read() ...);
bizzleState.clear();
}
}
There is not automatic garbage collection of state if you use GlobalWindows. Only if you use some non-global window will state be garbage collected after the watermark passes the end of a window plus the allowed lateness.
What you can do if you must work with GlobalWindows is to manually keep as state the last update timestamp. Then you would periodically set a timer where you check this timestamp against the current time and delete state if necessary. You would set this timer when encountering a key for the first time (which you can see from the absence of your timestamp state) and then re-set it in the #OnTimer method.
When utilising a Tango what would I use, callbacks or otherwise to detect when the devise has localised to a previously loaded ADF?
This is mainly for UI purposes in conjunction with Tango UX, telling a user to walk around an environment.
Localization may be detected when your TangoPoseData with a frame of ADF comes back valid.
Look at the Tango Java examples of AreaLearningActivity with this simplified logic:
//tell tango to provide pose for ADF
ArrayList<TangoCoordinateFramePair> framePairs = new ArrayList<TangoCoordinateFramePair>();
framePairs.add(new TangoCoordinateFramePair(
TangoPoseData.COORDINATE_FRAME_AREA_DESCRIPTION,
TangoPoseData.COORDINATE_FRAME_DEVICE));
//register a listener for the frames chosen
mTango.connectListener(framePairs, new OnTangoUpdateListener() {
//listens for updates from tango pose
public void onPoseAvailable(TangoPoseData pose) {
//base frame of ADF provides coordinates relative to the origin of the ADF
if (pose.baseFrame == TangoPoseData.COORDINATE_FRAME_AREA_DESCRIPTION
&& pose.targetFrame == TangoPoseData.COORDINATE_FRAME_DEVICE)
//if the status is valid then localization has succeeded
if(pose.statusCode == TangoPoseData.POSE_VALID){
Log.i(TAG,"Successfully localized with ADF");
}
}
}
Your config must indicate which ADF is of interest:
config.putString(TangoConfig.KEY_STRING_AREADESCRIPTION,adfId);
This process is not easily observed from the code, but I discovered it debugging the AreaLearningActivity example. The Java API would benefit from a higher level of abstraction making the common scenario you requested more obvious and easier to use:
TangoLocalizer.builder().register(myListener).adfId(myAdfId).build();
In Unity3D, you can use pose.status_code inside OnTangoPoseAvailable(TangoPoseData) for checking the checking the status (VALID/INVALID) of pose w.r.t. the coordinate frame pair defined.
For Device Localization you need to set targetFrame as TANGO_COORDINATE_FRAME_DEVICE AND baseFrame as TANGO_COORDINATE_FRAME_AREA_DESCRIPTION
public void OnTangoPoseAvailable(TangoPoseData pose)
{
// Define the frame-pair
if (pose.framePair.baseFrame == TangoEnums.TangoCoordinateFrameType.TANGO_COORDINATE_FRAME_AREA_DESCRIPTION
&& pose.framePair.targetFrame == TangoEnums.TangoCoordinateFrameType.TANGO_COORDINATE_FRAME_DEVICE)
{
// Check if the pose is VALID or INVALID
if (pose.status_code == TangoEnums.TangoPoseStatusType.TANGO_POSE_VALID)
{
////......if pose is VALID
}
else
{
////......if pose is INVALID
}
}
}
You also need to load the ADF using m_tangoApplication.Startup (m_selectedADF); as well.
I want to load some content or page in a JavaFX WebView and offer a Bridge object to Java so the content of the page can do calls into java.
The basic concept of how to do this is described here: https://blogs.oracle.com/javafx/entry/communicating_between_javascript_and_javafx
Now my question is: When is a good time inject the bridge-object into the WebView so it is available as soon as possible.
One option would be after page load as described here: https://stackoverflow.com/a/17612361/1520422
But is there a way to inject this sooner (before the page content itself is initialized), so the bridge-object is available DURING page-load (and not only after page-load)?
Since no one has answered, I'll tell you how I'm doing it, although it is ugly. This provides the ability for the page to function normally in non-Java environments but receive a Java object in Java environments.
I start by providing an onStatusChanged handler to the WebEngine. It listens for a magic value for window.status. If the magic value is received, the handler installs the Java object. (In my case, it's more complex, because I have some more complex orchestration: I'm executing a script that provides a client-side API for the page and then sets another magic value on window.status to cause the Java object to be sent to an initialization method of the client-side API).
Then in my target page, I have the following code in the first script in the page:
window.status = "MY-MAGIC-VALUE";
window.status = "";
This code is essentially a no-op in a "normal" browser but triggers the initialization when running in the custom JavaFX embedding.
In Java 8, you can trigger event changing from SCHEDULED to RUNNING to inject objects at this time. The objects will present in WebEngine before JavaScript running. Java 7, I see the state machine quite differs in operating, no solution given for Java 7.
webEngine.getLoadWorker().stateProperty().addListener(
new ChangeListener<State>(){
public void changed(ObservableValue<? extends State> ov,
State oldState,
State newState)
{
// System.out.println("old: "+oldState+", new: "+newState);
if(newState == State.RUNNING &&
oldState == State.SCHEDULED){
JSObject window = (JSObject)webEngine.executeScript("window");
window.setMember("foutput", foutput);
}
}
});
Somewhere in my Vaadin application, I'm getting this exception as soon as I connect using a second browser
Caused by: java.lang.RuntimeException: A connector with id 22 is already registered!
at com.vaadin.ui.ConnectorTracker.registerConnector(ConnectorTracker.java:133)
It happens always in the same place but I don't know why exactly as the reason for this must be somewhere else.
I think I might be stealing UI components from the other session - which is not my intention.
Currently, I don't see any static instances of UI components I might be using in multiple sessions.
How can I debug this? It's become quite a large project.
Any hints to look for?
Yes, this usually happens because you are attaching a component already attached in other session.
Try logging the failed connector with a temporal ConnectorTracker, So the next time that it happens, you can catch it.
For example:
public class SomeUI extends UI {
private ConnectorTracker tracker;
#Override
public ConnectorTracker getConnectorTracker() {
if (this.tracker == null) {
this.tracker = new ConnectorTracker(this) {
#Override
public void registerConnector(ClientConnector connector) {
try {
super.registerConnector(connector);
} catch (RuntimeException e) {
getLogger().log(Level.SEVERE, "Failed connector: {0}", connector.getClass().getSimpleName());
throw e;
}
}
};
}
return tracker;
}
}
I think I might be stealing UI components from the other session - which is not my intention. Currently, I don't see any static instances of UI components I might be using in multiple sessions.
That was it. I was actually stealing UI components without prior knowledge.
It was very well hidden in a part which seems to be same for all instances. Which is true: the algorithm is the same.
Doesn't mean I should've reused the same UI components as well...
Thanks to those who took a closer look.
Here is how I fixed it -
1) look for components you have shared across sessions. For example if you have declared a component as static it will be created once and will be shared.
2) if you are not able to find it and want a work around until you figure out the real problem, put your all addComponent calls in try and in catch add following code -
getUI().getConnectorTracker().markAllConnectorsDirty();
getUI().getConnectorTracker().markAllClientSidesUnititialized();
getPage().reload():
This will clear old connectors and will reload the page properly only when it fails. For me it was failing when I was logged out and logged in back.
Once you find the real problem you can fix it till then inform your customers about the reload.
**** note - only solution is to remove shared components this is just a work around.
By running your application in debug mode (add ?debug at the end of URL in browser) you will be able to browse to the component, e.g:
-UIConnector(0)
--VerticalLayoutConnector(1)
---...
---LabelConnector(22)
where 22 is id from your stack trace. Find this component in your code and make sure that it is not static (yes, I saw such examples).