RxBinding for ChipGroup checked events

dependencies.gradle

@@ -1,18 +1,19 @@
 ext {
   androidPlugin = 'com.android.tools.build:gradle:3.0.1'
   minSdkVersion = 14
-  compileSdkVersion = 27
+  compileSdkVersion = 28
 
   kotlinPlugin = 'org.jetbrains.kotlin:kotlin-gradle-plugin:1.2.21'
   kotlinStdlib = 'org.jetbrains.kotlin:kotlin-stdlib:1.2.21'
   kotlinPoet = 'com.squareup:kotlinpoet:0.6.0'
 
-  supportVersion = '27.0.2'
+  supportVersion = '28.0.0-alpha1'
   supportAnnotations = "com.android.support:support-annotations:$supportVersion"
   supportV4CoreUi = "com.android.support:support-core-ui:$supportVersion"
   supportRecyclerView = "com.android.support:recyclerview-v7:$supportVersion"
   supportAppCompat = "com.android.support:appcompat-v7:$supportVersion"
   supportDesign = "com.android.support:design:$supportVersion"
+  supportDesignChip = "com.android.support:design-chip:$supportVersion"
   supportLeanback = "com.android.support:leanback-v17:$supportVersion"
 
   autoValue = 'com.google.auto.value:auto-value:1.5.2'

rxbinding-design-chip/.gitignore

@@ -0,0 +1 @@
+/build

rxbinding-design-chip/build.gradle

@@ -0,0 +1,57 @@
+buildscript {
+    dependencies {
+        classpath rootProject.ext.androidPlugin
+    }
+}
+
+apply plugin: 'com.android.library'
+apply plugin: 'rxbinding-module'
+
+dependencies {
+    api project(':rxbinding')
+    api rootProject.ext.supportDesignChip
+    implementation rootProject.ext.rxAndroid
+    implementation rootProject.ext.supportAnnotations
+
+    compileOnly rootProject.ext.autoValueAnnotations
+    annotationProcessor rootProject.ext.autoValue
+
+    androidTestImplementation project(':testing-utils')
+    androidTestImplementation rootProject.ext.supportTestRunner
+    androidTestImplementation rootProject.ext.supportTestRules
+    androidTestImplementation rootProject.ext.supportTestEspresso
+    androidTestImplementation rootProject.ext.rxAndroid
+}
+
+android {
+    compileSdkVersion rootProject.ext.compileSdkVersion
+
+    defaultConfig {
+        minSdkVersion rootProject.ext.minSdkVersion
+
+        testInstrumentationRunner 'com.jakewharton.rxbinding.RxBindingTestRunner'
+    }
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_7
+        targetCompatibility JavaVersion.VERSION_1_7
+    }
+
+    lintOptions {
+        textReport true
+        textOutput 'stdout'
+    }
+
+    buildTypes {
+        debug {
+            testCoverageEnabled true
+        }
+    }
+
+    // TODO replace with https://issuetracker.google.com/issues/72050365 once released.
+    libraryVariants.all {
+        it.generateBuildConfig.enabled = false
+    }
+}
+
+apply from: rootProject.file('gradle/gradle-mvn-push.gradle')

rxbinding-design-chip/gradle.properties

@@ -0,0 +1,3 @@
+POM_ARTIFACT_ID=rxbinding-design-chip
+POM_NAME=RxBinding (design-chip)
+POM_PACKAGING=aar

rxbinding-design-chip/src/androidTest/java/com/jakewharton/rxbinding2/support/design/chip/RxChipGroupTest.java

@@ -0,0 +1,72 @@
+package com.jakewharton.rxbinding2.support.design.chip;
+
+import android.content.Context;
+import android.support.design.chip.Chip;
+import android.support.design.chip.ChipGroup;
+import android.support.test.InstrumentationRegistry;
+import android.support.test.annotation.UiThreadTest;
+import android.support.test.rule.UiThreadTestRule;
+import android.support.test.runner.AndroidJUnit4;
+import android.support.v7.view.ContextThemeWrapper;
+import android.view.View;
+
+import com.jakewharton.rxbinding2.RecordingObserver;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import io.reactivex.functions.Consumer;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(AndroidJUnit4.class)
+@SuppressWarnings("ResourceType") // Don't need real IDs for test case.
+public final class RxChipGroupTest {
+  @Rule public final UiThreadTestRule uiThread = new UiThreadTestRule();
+
+  private final Context context = new ContextThemeWrapper(InstrumentationRegistry.getContext(), R.style.Theme_AppCompat);
+  private final ChipGroup view = new ChipGroup(context);
+
+  @Before public void setUp() {
+    view.setSingleSelection(true);
+    Chip button1 = new Chip(context);
+    button1.setId(1);
+    view.addView(button1);
+    Chip button2 = new Chip(context);
+    button2.setId(2);
+    view.addView(button2);
+  }
+
+  @Test @UiThreadTest public void checkedChanges() {
+    RecordingObserver<Integer> o = new RecordingObserver<>();
+    RxChipGroup.checkedChanges(view).subscribe(o);
+    assertEquals(View.NO_ID, o.takeNext().intValue());
+
+    view.check(1);
+    assertEquals(1, o.takeNext().intValue());
+
+    view.clearCheck();
+    assertEquals(View.NO_ID, o.takeNext().intValue());
+
+    view.check(2);
+    assertEquals(2, o.takeNext().intValue());
+
+    o.dispose();
+
+    view.check(1);
+    o.assertNoMoreEvents();
+  }
+
+  @Test @UiThreadTest public void checked() throws Exception {
+    Consumer<? super Integer> action = RxChipGroup.checked(view);
+    assertEquals(View.NO_ID, view.getCheckedChipId());
+    action.accept(1);
+    assertEquals(1, view.getCheckedChipId());
+    action.accept(View.NO_ID);
+    assertEquals(View.NO_ID, view.getCheckedChipId());
+    action.accept(2);
+    assertEquals(2, view.getCheckedChipId());
+  }
+}

rxbinding-design-chip/src/main/AndroidManifest.xml

@@ -0,0 +1 @@
+<manifest package="com.jakewharton.rxbinding2.support.design.chip" />

rxbinding-design-chip/src/main/java/com/jakewharton/rxbinding2/support/design/chip/ChipGroupCheckedChangeObservable.java

@@ -0,0 +1,58 @@
+package com.jakewharton.rxbinding2.support.design.chip;
+
+import android.support.design.chip.ChipGroup;
+import android.support.design.chip.ChipGroup.OnCheckedChangeListener;
+import android.view.View;
+
+import com.jakewharton.rxbinding2.InitialValueObservable;
+import io.reactivex.Observer;
+import io.reactivex.android.MainThreadDisposable;
+
+import static com.jakewharton.rxbinding2.internal.Preconditions.checkMainThread;
+
+final class ChipGroupCheckedChangeObservable extends InitialValueObservable<Integer> {
+    private final ChipGroup view;
+
+    ChipGroupCheckedChangeObservable(ChipGroup view) {
+        this.view = view;
+    }
+
+    @Override
+    protected void subscribeListener(Observer<? super Integer> observer) {
+        if (!checkMainThread(observer)) {
+            return;
+        }
+        Listener listener = new Listener(view, observer);
+        view.setOnCheckedChangeListener(listener);
+        observer.onSubscribe(listener);
+    }
+
+    @Override
+    protected Integer getInitialValue() {
+        return view.getCheckedChipId();
+    }
+
+    static final class Listener extends MainThreadDisposable implements OnCheckedChangeListener {
+        private final ChipGroup view;
+        private final Observer<? super Integer> observer;
+        private int lastChecked = View.NO_ID;
+
+        Listener(ChipGroup view, Observer<? super Integer> observer) {
+            this.view = view;
+            this.observer = observer;
+        }
+
+        @Override
+        public void onCheckedChanged(ChipGroup chipGroup, int checkedId) {
+            if (!isDisposed() && checkedId != lastChecked) {
+                lastChecked = checkedId;
+                observer.onNext(checkedId);
+            }
+        }
+
+        @Override
+        protected void onDispose() {
+            view.setOnCheckedChangeListener(null);
+        }
+    }
+}

rxbinding-design-chip/src/main/java/com/jakewharton/rxbinding2/support/design/chip/RxChipGroup.java

@@ -0,0 +1,55 @@
+package com.jakewharton.rxbinding2.support.design.chip;
+
+import android.support.annotation.CheckResult;
+import android.support.annotation.NonNull;
+import android.support.design.chip.ChipGroup;
+import android.view.View;
+import com.jakewharton.rxbinding2.InitialValueObservable;
+import io.reactivex.functions.Consumer;
+
+import static com.jakewharton.rxbinding2.internal.Preconditions.checkNotNull;
+
+public final class RxChipGroup {
+    /**
+     * Create an observable of the checked chip ID changes in {@code view}.
+     * <p>
+     * <em>Warning:</em> The created observable keeps a strong reference to {@code view}. Unsubscribe
+     * to free this reference.
+     * </p>
+     * <p>
+     * <em>Note:</em> A value will be emitted immediately on subscribe
+     * </p>
+     */
+    @CheckResult @NonNull
+    public static InitialValueObservable<Integer> checkedChanges(@NonNull ChipGroup view) {
+        checkNotNull(view, "view == null");
+        return new ChipGroupCheckedChangeObservable(view);
+    }
+
+    /**
+     * An action which sets the checked child of {@code view} with ID. Passing {@code View.NO_ID} will clear
+     * any checked view.
+     * <p>
+     * <em>Warning:</em> The created observable keeps a strong reference to {@code view}. Unsubscribe
+     * to free this reference
+     * </p>
+     */
+    @CheckResult @NonNull
+    public static Consumer<? super Integer> checked(@NonNull final ChipGroup view) {
+        checkNotNull(view, "view == null");
+        return new Consumer<Integer>() {
+            @Override
+            public void accept(Integer value) {
+                if (value == View.NO_ID) {
+                    view.clearCheck();
+                } else {
+                    view.check(value);
+                }
+            }
+        };
+    }
+
+    private RxChipGroup() {
+        throw new AssertionError("No instances.");
+    }
+}

settings.gradle

@@ -8,6 +8,7 @@ include ':rxbinding-appcompat-v7-kotlin'
 
 include ':rxbinding-design'
 include ':rxbinding-design-kotlin'
+include ':rxbinding-design-chip'
 
 include ':rxbinding-support-v4'
 include ':rxbinding-support-v4-kotlin'