The Kotlin bindings are fun, but are completely mechanical in how they are created. There's no reason they should be created by hand and doing so is an error-prone endeavor. Write a script that parses the Java declarations and automatically generates them for all modules. Care must be taken for all the variations of things like Javadoc, generics, and multiple arguments.

There's currently two patterns for events that have multiple "actions" associated with them (for lack of a better term):

• Subclass a common event type: AbstractFooEvent + FirstFooEvent + SecondFooEvent
• Put an enum on a single event type: FooEvent with FooEvent.Kind enum and property.

Which of these do we want to standardize on?

Subclassing feels gross since the more specific types do not add any more information to the event (note: counter example below) and add multiple types to the public API, but it also allows RxJava's filter+cast operator ofType to be used. Putting an inner-enum on a single event type keeps the public API small and we could change these to implement Func1<EventType, Boolean> for use as a filter (e.g., .filter(FooEvent.Kind.FIRST)).

Great to see the ideas in this project! I wanted to submit one more idea for feedback:

By default, the HandlerScheduler always calls postDelayed, even if delayTime <= 0 && Looper.myLooper() == handler.getLooper().

I've found it useful to have a scheduler that behaves more like Schedulers.immediate() in this scenario. The main benefits are immediate execution with no delay (nothing to schedule) and preservation of the call stack when debugging.

There's already enough hooks to swap out the default scheduler, but I'd be curious to see if anybody else finds this idea valuable and if it would be reasonable to make it the default behavior.

RxTextView.textChanges(searchEditText)
          .delay(2, TimeUnit.SECONDS)
          .subscrite(
              ret -> {}
          )

I bind the text changes event with a edittext widget. When I input some text to the edittext quickly, the ret always be the string that is the final text I writing. I think it's wrong.

In my opinion, the ret will be the sequences which I write.

The android x libraries are currently at release candidate versions so I figured it'd be a good time to discuss this. Hopefully migrating RxBinding will just involve a whole lot of renaming of imports, but what will this mean for the version number? This is technically a breaking change for some of the modules, so does this mean we change to 3.0?

Happy to some some legwork here, I just want to know how this should be approached. Are there any other considerations when migrating? Or is the plan to just let Jetifier handle things for now?

@JakeWharton Calling TabLayout's selections will cause an error. How can I fix this?

Version: rxbinding:3.0.0-alpha2

Code:

        tab_layout
                .selections()
                .compose(bindUntilEvent(FragmentEvent.DESTROY_VIEW))
                .subscribe {
                    when (it.position) {
                        0 -> setFabIcon(R.drawable.ic_fab_create_black_24dp)
                        1 -> setFabIcon(R.drawable.ic_person_add_black_24dp)
                        2 -> floating_action_button.hide()
                        3 -> floating_action_button.hide()
                    }
                }.isDisposed

        <com.google.android.material.tabs.TabLayout
            android:id="@+id/tab_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:tabMaxWidth="0dp"
            app:tabGravity="fill"
            app:tabMode="scrollable" />

Error:

    io.reactivex.exceptions.UndeliverableException: The exception could not be delivered to the consumer because it has already canceled/disposed the flow or the exception has nowhere to go to begin with. Further reading: https://github.com/ReactiveX/RxJava/wiki/What's-different-in-2.0#error-handling | java.lang.ClassCastException: com.jakewharton.rxbinding3.material.TabLayoutSelectionsObservable$Listener cannot be cast to com.google.android.material.tabs.TabLayout$BaseOnTabSelectedListener
        at io.reactivex.plugins.RxJavaPlugins.onError(RxJavaPlugins.java:367)
        at io.reactivex.Observable.subscribe(Observable.java:12097)
        at io.reactivex.Observable.subscribe(Observable.java:12076)
        at io.reactivex.Observable.subscribe(Observable.java:11979)

I had to change the generated RxRecyclerViewAdapter.kt manualy to fix recyclerview-v7-kotlin build since KotlinGenTask doesnt seem to support nested levels of parameterized types. I'm not familiar with kotlin and groovy, but i will continue looking at fixing kotlin generated code for this but thought i would start with this PR first.

I'm using rxbinding 2.2.0 with Kotlin 1.2.71 and AS 3.2.0 with Jetifier enabled (using the gradle kotlin dsl). When I build, I get the following error:

> Task :app:transformClassesWithDexBuilderForDebug
com.android.builder.dexing.DexArchiveBuilderException: com.android.builder.dexing.DexArchiveBuilderException: Failed to process /home/eli/.gradle/caches/transforms-1/files-1.1/jetified-rxbinding-2.2.0.aar/cbeb1358418963ecc6ffac36248ae851/jars/classes.jar
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at java.util.concurrent.ForkJoinTask.getThrowableException(ForkJoinTask.java:593)
	at java.util.concurrent.ForkJoinTask.reportException(ForkJoinTask.java:677)
	at java.util.concurrent.ForkJoinTask.join(ForkJoinTask.java:720)
	at com.android.ide.common.internal.WaitableExecutor.waitForTasksWithQuickFail(WaitableExecutor.java:146)
	at com.android.build.gradle.internal.transforms.DexArchiveBuilderTransform.transform(DexArchiveBuilderTransform.java:405)
	at com.android.build.gradle.internal.pipeline.TransformTask$2.call(TransformTask.java:239)
	at com.android.build.gradle.internal.pipeline.TransformTask$2.call(TransformTask.java:235)
	at com.android.builder.profile.ThreadRecorder.record(ThreadRecorder.java:102)
	at com.android.build.gradle.internal.pipeline.TransformTask.transform(TransformTask.java:230)
	at sun.reflect.GeneratedMethodAccessor1005.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:73)
	at org.gradle.api.internal.project.taskfactory.IncrementalTaskAction.doExecute(IncrementalTaskAction.java:50)
	at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:39)
	at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:26)
	at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$1.run(ExecuteActionsTaskExecuter.java:131)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:300)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:292)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:174)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:90)
	at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
	at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:120)
	at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:99)
	at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:77)
	at org.gradle.api.internal.tasks.execution.OutputDirectoryCreatingTaskExecuter.execute(OutputDirectoryCreatingTaskExecuter.java:51)
	at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:59)
	at org.gradle.api.internal.tasks.execution.ResolveTaskOutputCachingStateExecuter.execute(ResolveTaskOutputCachingStateExecuter.java:54)
	at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:59)
	at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:101)
	at org.gradle.api.internal.tasks.execution.FinalizeInputFilePropertiesTaskExecuter.execute(FinalizeInputFilePropertiesTaskExecuter.java:44)
	at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:91)
	at org.gradle.api.internal.tasks.execution.ResolveTaskArtifactStateTaskExecuter.execute(ResolveTaskArtifactStateTaskExecuter.java:62)
	at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:59)
	at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:54)
	at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
	at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:34)
	at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.run(EventFiringTaskExecuter.java:51)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:300)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:292)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:174)
	at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:90)
	at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
	at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:46)
	at org.gradle.execution.taskgraph.LocalTaskInfoExecutor.execute(LocalTaskInfoExecutor.java:42)
	at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareWorkItemExecutor.execute(DefaultTaskExecutionGraph.java:277)
	at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareWorkItemExecutor.execute(DefaultTaskExecutionGraph.java:262)
	at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$ExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:135)
	at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$ExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:130)
	at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$ExecutorWorker.execute(DefaultTaskPlanExecutor.java:200)
	at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$ExecutorWorker.executeWithWork(DefaultTaskPlanExecutor.java:191)
	at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$ExecutorWorker.run(DefaultTaskPlanExecutor.java:130)
	at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
	at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
	at java.lang.Thread.run(Thread.java:745)
Caused by: com.android.builder.dexing.DexArchiveBuilderException: Failed to process /home/eli/.gradle/caches/transforms-1/files-1.1/jetified-rxbinding-2.2.0.aar/cbeb1358418963ecc6ffac36248ae851/jars/classes.jar
	at com.android.build.gradle.internal.transforms.DexArchiveBuilderTransform.launchProcessing(DexArchiveBuilderTransform.java:900)
	at com.android.build.gradle.internal.transforms.DexArchiveBuilderTransform.lambda$convertToDexArchive$6(DexArchiveBuilderTransform.java:825)
	at java.util.concurrent.ForkJoinTask$AdaptedCallable.exec(ForkJoinTask.java:1424)
	at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
	at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
	at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
	at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)
Caused by: com.android.builder.dexing.DexArchiveBuilderException: Error while dexing.
The dependency contains Java 8 bytecode. Please enable desugaring by adding the following to build.gradle
android {
    compileOptions {
        sourceCompatibility 1.8
        targetCompatibility 1.8
    }
}
See https://developer.android.com/studio/write/java8-support.html for details. Alternatively, increase the minSdkVersion to 26 or above.

	at com.android.builder.dexing.D8DexArchiveBuilder.getExceptionToRethrow(D8DexArchiveBuilder.java:124)
	at com.android.builder.dexing.D8DexArchiveBuilder.convert(D8DexArchiveBuilder.java:101)
	at com.android.build.gradle.internal.transforms.DexArchiveBuilderTransform.launchProcessing(DexArchiveBuilderTransform.java:895)
	... 6 more
Caused by: com.android.tools.r8.CompilationFailedException: Compilation failed to complete
	at com.android.tools.r8.utils.ExceptionUtils.withCompilationHandler(ExceptionUtils.java:65)
	at com.android.tools.r8.utils.ExceptionUtils.withD8CompilationHandler(ExceptionUtils.java:43)
	at com.android.tools.r8.D8.run(D8.java:90)
	at com.android.builder.dexing.D8DexArchiveBuilder.convert(D8DexArchiveBuilder.java:99)
	... 7 more
Caused by: com.android.tools.r8.utils.AbortException: Error: Invoke-customs are only supported starting with Android O (--min-api 26)
	at com.android.tools.r8.utils.Reporter.failIfPendingErrors(Reporter.java:116)
	at com.android.tools.r8.utils.Reporter.fatalError(Reporter.java:74)
	at com.android.tools.r8.utils.ExceptionUtils.withCompilationHandler(ExceptionUtils.java:59)
	... 10 more


> Task :app:transformClassesWithDexBuilderForDebug FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:transformClassesWithDexBuilderForDebug'.
> com.android.build.api.transform.TransformException: com.android.builder.dexing.DexArchiveBuilderException: com.android.builder.dexing.DexArchiveBuilderException: Failed to process /home/eli/.gradle/caches/transforms-1/files-1.1/jetified-rxbinding-2.2.0.aar/cbeb1358418963ecc6ffac36248ae851/jars/classes.jar

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

https://github.com/JakeWharton/RxBinding/blob/master/rxbinding-design-kotlin/src/main/kotlin/com/jakewharton/rxbinding/support/design/widget/RxTextInputLayout.kt#L28

Not using CharSequence? means the error cannot be unset via a null value, as per the documentation.

This PR switches the Kotlin code gen to use KotlinPoet rather than the manual approach. KotlinPoet's in a good place for this now, so I figured it would be a good opportunity to exercise it!

Commits are small-ish and broken down to digestible units, but don't all compile on their own. Tried to make this as CR-friendly as possible, and only the last commit actually regenerates the kotlin files.

Some notes:

• kotlinOptions.moduleName no longer exists, and I couldn't find any docs on what happened with it. Removed as part of upgrading in 1b594dc.
• JavaParser doesn't yield fully qualified class names for types. This was sort of ok in the previous implementation because we'd manually add all the imports from the target class to the kotlin file anyway. We can't just tack on imports in KotlinPoet though, so this tries to be smarter about it, albeit in a sort of unfortunate way. To do this, I read the imports first and associate them into a mapping of simple name -> ClassName, which I then pass around in the type resolution to give it a chance. The idea is that if it's referenced by simple name in the target class and safe with imports, then we can do the same in the kotlin files. In testing, this proved to work fine.
• JavaParser has seen a lot of updates and we're a major version behind. Looks like there are breaking changes too, so just updated to the last 2.x version here. We don't really need the new stuff fortunately, and the newer versions don't help with the fqcn issue above either anyway.
• KotlinPoet doesn't put newlines between fun emissions 🤔

Note sure if this is by design or not, but the exceptions thrown by verifyMainThread() fail hard rather than going to onError() (since it doesn't know the disposed state during the calling subscribe and will just bubble it straight to RxJavaPlugins#onError() or throw. Since we have the observer there, should we send the exception to its onError() instead?

Specifically, I think this is actually a significant behavior change from the implementation in RxJava 1 or using create(), which would send this to onError().

Result is if you want to gracefully handle that case, you end up having to try/catch the actual subscribe() call itself

Currently, the onFocusChangeListener is always set to null when disposed, regardless of what the field is actually set to.
This could lead to some unexpected behavior when the focus change listener is changed manually, after subscribing to the observable.

When we first check that the currently set listener is this, then won't override any manually set listener.

The comment states that:

 * @param handled Predicate invoked each occurrence to determine the return value of the
 * underlying [TextView.OnEditorActionListener].

But the code seems to use the handler predicate to filter the events and always returns true when the event is sent to the observer:

      try {
        if (!isDisposed && handled(actionId)) {
          observer.onNext(actionId)
          return true
        }
      } catch (e: Exception) {
        observer.onError(e)
        dispose()
      }

      return false

Perhaps two predicates? One for the filtering and one for the return value.

Or at least a fix for the comment.

The same issue is found in TextView.editorActionEvents.

I see that there is a consumer to set the view's visibility but I couldn't find an observable variant for the same. I'm trying to do something like this (for now I used a workaround but ideally an observable that emits visibility changes would be the best for this job):

secondItem.visibility()
  .subscribe ({ 
    if(it == View.VISIBLE) {
      (itemWhichShouldFillLayout.layoutParams as LinearLayout.LayoutParams).weight = 0.65f
    } else {
      (itemWhichShouldFillLayout.layoutParams as LinearLayout.LayoutParams).weight = 0.8f
    }
})

Hi, Thank for great work

Can you implement this override fun onQueryTextSubmit(query: String) = false.

I want to capture Search button on the keyboard.

Thanks so much,