How to create a MotionEvent for unit testing in Android Studio?

Question

I want to test a joystick module, to be more specific i'm trying to test axis movement, but i can't because MotionEvent.obtain seems to be returning a null value.

This is my test.

public void test_onGenericMotionEvent() {
    MotionEvent motionEvent;
    // Motion joystick event test
    motionEvent = MotionEvent.obtain(200, 300,
            MotionEvent.ACTION_MOVE, 1.0f, 0.0f, 0);
    motionEvent.setSource(InputDevice.SOURCE_JOYSTICK); // <-- ERROR
    assertTrue(joystickView.onGenericMotionEvent(motionEvent));
}

And i'm getting this error:

java.lang.NullPointerException
    at com.aquarov.rovcontrollerclient.JoystickViewUnitTest.test_onGenericMotionEvent(JoystickViewUnitTest.java:33)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

Answer 1

here is documentation how to achieve it dispatchTouchEvent()

kotlin example:

 val motionEvent = MotionEvent.obtain(200, 300, MotionEvent.ACTION_MOVE, 1.0f, 0.0f, 0)
    motionEvent.source = InputDevice.SOURCE_JOYSTICK
    yourView.dispatchGenericMotionEvent(motionEvent)