Add bindings for legacy ViewPager.

README.md

@@ -157,6 +157,7 @@ List of all bindings available:
 * [AndroidX Preference bindings][flowbinding-preference]
 * [AndroidX RecyclerView bindings][flowbinding-recyclerview]
 * [AndroidX SwipeRefreshLayout bindings][flowbinding-swiperefreshlayout]
+* [AndroidX ViewPager bindings][flowbinding-viewpager]
 * [AndroidX ViewPager2 bindings][flowbinding-viewpager2]
 * [Material Components bindings][flowbinding-material]
 
@@ -204,4 +205,5 @@ limitations under the License.
 [flowbinding-preference]: flowbinding-preference/
 [flowbinding-recyclerview]: flowbinding-recyclerview/
 [flowbinding-swiperefreshlayout]: flowbinding-swiperefreshlayout/
+[flowbinding-viewpager]: flowbinding-viewpager/
 [flowbinding-viewpager2]: flowbinding-viewpager2/

buildSrc/dependencies.gradle

@@ -18,6 +18,7 @@ rootProject.ext.versions = [
                 fragment          : '1.3.0-alpha03',
                 coordinatorLayout : '1.1.0',
                 recyclerView      : '1.2.0-alpha02',
+                viewPager         : '1.0.0',
                 viewPager2        : '1.1.0-alpha01',
                 swipeRefreshLayout: '1.1.0-rc01',
                 drawerLayout      : '1.1.0-beta01',

flowbinding-viewpager/README.md

@@ -0,0 +1,21 @@
+# FlowBinding ViewPager
+
+This module provides bindings for the **AndroidX ViewPager** library.
+
+## Transitive Dependency
+
+`androidx.viewpager:viewpager`
+
+## Download
+
+```groovy
+implementation "io.github.reactivecircus.flowbinding:flowbinding-viewpager:${flowbinding_version}"
+```
+
+## Available Bindings
+
+```kotlin
+fun ViewPager.pageScrollEvents(): Flow<ViewPagerPageScrollEvent>
+fun ViewPager.pageScrollStateChanges(): Flow<Int>
+fun ViewPager.pageSelections(emitImmediately: Boolean = false): Flow<Int>
+```

flowbinding-viewpager/api/flowbinding-viewpager.api

@@ -0,0 +1,21 @@
+public final class reactivecircus/flowbinding/viewpager/ViewPagerPageScrollEvent {
+	public fun <init> (Landroidx/viewpager/widget/ViewPager;IFI)V
+	public final fun getPosition ()I
+	public final fun getPositionOffset ()F
+	public final fun getPositionOffsetPixel ()I
+	public final fun getView ()Landroidx/viewpager/widget/ViewPager;
+}
+
+public final class reactivecircus/flowbinding/viewpager/ViewPagerPageScrollStateChangedFlowKt {
+	public static final fun pageScrollStateChanges (Landroidx/viewpager/widget/ViewPager;)Lkotlinx/coroutines/flow/Flow;
+}
+
+public final class reactivecircus/flowbinding/viewpager/ViewPagerPageScrolledFlowKt {
+	public static final fun pageScrollEvents (Landroidx/viewpager/widget/ViewPager;)Lkotlinx/coroutines/flow/Flow;
+}
+
+public final class reactivecircus/flowbinding/viewpager/ViewPagerPageSelectedFlowKt {
+	public static final fun pageSelections (Landroidx/viewpager/widget/ViewPager;Z)Lkotlinx/coroutines/flow/Flow;
+	public static synthetic fun pageSelections$default (Landroidx/viewpager/widget/ViewPager;ZILjava/lang/Object;)Lkotlinx/coroutines/flow/Flow;
+}
+

flowbinding-viewpager/build.gradle

@@ -0,0 +1,35 @@
+plugins {
+    id 'flowbinding-plugin'
+    id 'com.android.library'
+    id 'kotlin-android'
+    id 'com.vanniktech.maven.publish'
+    id 'io.github.reactivecircus.firestorm'
+    id 'org.jetbrains.dokka'
+}
+
+afterEvaluate { project ->
+    project.tasks.dokka {
+        outputDirectory = "$rootDir/docs/api"
+        outputFormat = 'gfm'
+    }
+}
+
+android {
+    defaultConfig {
+        testApplicationId 'reactivecircus.flowbinding.viewpager.test'
+        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+    }
+}
+
+dependencies {
+    implementation project(':flowbinding-common')
+
+    implementation "androidx.viewpager:viewpager:${versions.androidx.viewPager}"
+    implementation "androidx.fragment:fragment:${versions.androidx.fragment}"
+    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:${versions.kotlinx.coroutines}"
+
+    lintChecks project(":lint-rules")
+
+    androidTestImplementation project(':testing-infra')
+    androidTestImplementation project(':flowbinding-viewpager:fixtures')
+}

flowbinding-viewpager/fixtures/build.gradle

@@ -0,0 +1,13 @@
+plugins {
+    id 'flowbinding-plugin'
+    id 'com.android.library'
+    id 'kotlin-android'
+}
+
+android.buildFeatures.viewBinding = true
+
+dependencies {
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:${versions.kotlin}"
+    implementation "androidx.viewpager:viewpager:${versions.androidx.viewPager}"
+    implementation "androidx.fragment:fragment:${versions.androidx.fragment}"
+}

flowbinding-viewpager/fixtures/src/main/AndroidManifest.xml

@@ -0,0 +1 @@
+<manifest package="reactivecircus.flowbinding.viewpager.fixtures" />

flowbinding-viewpager/fixtures/src/main/java/reactivecircus/flowbinding/viewpager/fixtures/ViewPagerFragment.kt

@@ -0,0 +1,41 @@
+@file:Suppress("DEPRECATION")
+
+package reactivecircus.flowbinding.viewpager.fixtures
+
+import android.os.Bundle
+import android.view.View
+import androidx.fragment.app.Fragment
+import androidx.fragment.app.FragmentManager
+import androidx.fragment.app.FragmentStatePagerAdapter
+import reactivecircus.flowbinding.viewpager.fixtures.databinding.FragmentPageItemBinding
+import reactivecircus.flowbinding.viewpager.fixtures.databinding.FragmentViewpagerBinding
+
+class ViewPagerFragment : Fragment(R.layout.fragment_viewpager) {
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+        val binding = FragmentViewpagerBinding.bind(view)
+        binding.viewPager.adapter = PagerAdapter(parentFragmentManager)
+    }
+}
+
+private val pages = listOf("1", "2", "3")
+
+class PagerAdapter(
+    fragmentManager: FragmentManager
+) : FragmentStatePagerAdapter(fragmentManager, BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT) {
+    override fun getCount(): Int = pages.size
+
+    override fun getItem(position: Int): Fragment = PageItemFragment(
+        pages[position]
+    )
+}
+
+class PageItemFragment(private val pageTitle: String) : Fragment(R.layout.fragment_page_item) {
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        super.onViewCreated(view, savedInstanceState)
+        val binding = FragmentPageItemBinding.bind(view)
+        binding.pageTitleTextView.text = pageTitle
+    }
+}

flowbinding-viewpager/fixtures/src/main/res/layout/fragment_page_item.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <TextView
+        android:id="@+id/pageTitleTextView"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center" />
+
+</FrameLayout>

flowbinding-viewpager/fixtures/src/main/res/layout/fragment_viewpager.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.viewpager.widget.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/viewPager"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent" />

flowbinding-viewpager/gradle.properties

@@ -0,0 +1,4 @@
+POM_ARTIFACT_ID=flowbinding-viewpager
+POM_NAME=FlowBinding ViewPager
+POM_DESCRIPTION=Kotlin Flow binding APIs for AndroidX ViewPager
+POM_PACKAGING=aar

flowbinding-viewpager/src/androidTest/java/reactivecircus/flowbinding/viewpager/ViewPagerPageScrollStateChangedFlowTest.kt

@@ -0,0 +1,61 @@
+package reactivecircus.flowbinding.viewpager
+
+import androidx.test.filters.LargeTest
+import androidx.test.internal.runner.junit4.statement.UiThreadStatement.runOnUiThread
+import androidx.viewpager.widget.ViewPager
+import org.amshove.kluent.shouldEqual
+import org.junit.Test
+import reactivecircus.blueprint.testing.action.swipeLeftOnView
+import reactivecircus.blueprint.testing.action.swipeRightOnView
+import reactivecircus.flowbinding.testing.FlowRecorder
+import reactivecircus.flowbinding.testing.launchTest
+import reactivecircus.flowbinding.testing.recordWith
+import reactivecircus.flowbinding.viewpager.fixtures.ViewPagerFragment
+import reactivecircus.flowbinding.viewpager.test.R
+
+@LargeTest
+class ViewPagerPageScrollStateChangedFlowTest {
+
+    @Test
+    fun pageScrollStateChanges_swipe() {
+        launchTest<ViewPagerFragment> {
+            val recorder = FlowRecorder<Int>(testScope)
+            getViewById<ViewPager>(R.id.viewPager).pageScrollStateChanges().recordWith(recorder)
+
+            recorder.assertNoMoreValues()
+
+            swipeLeftOnView(R.id.viewPager)
+            recorder.takeValue() shouldEqual ViewPager.SCROLL_STATE_DRAGGING
+            recorder.takeValue() shouldEqual ViewPager.SCROLL_STATE_SETTLING
+            recorder.takeValue() shouldEqual ViewPager.SCROLL_STATE_IDLE
+            recorder.assertNoMoreValues()
+
+            cancelTestScope()
+
+            swipeRightOnView(R.id.viewPager)
+            recorder.assertNoMoreValues()
+        }
+    }
+
+    @Test
+    fun pageScrollStateChanges_programmatic() {
+        launchTest<ViewPagerFragment> {
+            val recorder = FlowRecorder<Int>(testScope)
+            val viewPager = getViewById<ViewPager>(R.id.viewPager)
+            viewPager.pageScrollStateChanges().recordWith(recorder)
+
+            recorder.assertNoMoreValues()
+
+            runOnUiThread { viewPager.currentItem = 1 }
+            // SCROLL_STATE_DRAGGING state is not emitted for programmatic page change
+            recorder.takeValue() shouldEqual ViewPager.SCROLL_STATE_SETTLING
+            recorder.takeValue() shouldEqual ViewPager.SCROLL_STATE_IDLE
+            recorder.assertNoMoreValues()
+
+            cancelTestScope()
+
+            runOnUiThread { viewPager.currentItem = 0 }
+            recorder.assertNoMoreValues()
+        }
+    }
+}

flowbinding-viewpager/src/androidTest/java/reactivecircus/flowbinding/viewpager/ViewPagerPageScrolledFlowTest.kt

@@ -0,0 +1,70 @@
+package reactivecircus.flowbinding.viewpager
+
+import androidx.test.filters.LargeTest
+import androidx.test.internal.runner.junit4.statement.UiThreadStatement.runOnUiThread
+import androidx.test.platform.app.InstrumentationRegistry.getInstrumentation
+import androidx.viewpager.widget.ViewPager
+import org.amshove.kluent.shouldBeGreaterThan
+import org.amshove.kluent.shouldEqual
+import org.junit.Test
+import reactivecircus.blueprint.testing.action.swipeLeftOnView
+import reactivecircus.blueprint.testing.action.swipeRightOnView
+import reactivecircus.flowbinding.testing.FlowRecorder
+import reactivecircus.flowbinding.testing.launchTest
+import reactivecircus.flowbinding.testing.recordWith
+import reactivecircus.flowbinding.viewpager.fixtures.ViewPagerFragment
+import reactivecircus.flowbinding.viewpager.test.R
+
+@LargeTest
+class ViewPagerPageScrolledFlowTest {
+
+    @Test
+    fun pageScrollEvents_swipe() {
+        launchTest<ViewPagerFragment> {
+            val recorder = FlowRecorder<ViewPagerPageScrollEvent>(testScope)
+            val viewPager = getViewById<ViewPager>(R.id.viewPager)
+            viewPager.pageScrollEvents().recordWith(recorder)
+
+            recorder.assertNoMoreValues()
+
+            swipeLeftOnView(R.id.viewPager)
+            val event = recorder.takeValue()
+            event.view shouldEqual viewPager
+            event.position shouldEqual 0
+            event.positionOffset shouldBeGreaterThan 0f
+            event.positionOffsetPixel shouldBeGreaterThan 0
+
+            cancelTestScope()
+            recorder.clearValues()
+
+            swipeRightOnView(R.id.viewPager)
+            recorder.assertNoMoreValues()
+        }
+    }
+
+    @Test
+    fun pageScrollEvents_programmatic() {
+        launchTest<ViewPagerFragment> {
+            val recorder = FlowRecorder<ViewPagerPageScrollEvent>(testScope)
+            val viewPager = getViewById<ViewPager>(R.id.viewPager)
+            viewPager.pageScrollEvents().recordWith(recorder)
+
+            recorder.assertNoMoreValues()
+
+            runOnUiThread { viewPager.currentItem = 1 }
+            getInstrumentation().waitForIdleSync()
+            val event = recorder.takeValue()
+            event.view shouldEqual viewPager
+            event.position shouldEqual 0
+            event.positionOffset shouldBeGreaterThan 0f
+            event.positionOffsetPixel shouldBeGreaterThan 0
+
+            cancelTestScope()
+            recorder.clearValues()
+
+            runOnUiThread { viewPager.currentItem = 0 }
+            getInstrumentation().waitForIdleSync()
+            recorder.assertNoMoreValues()
+        }
+    }
+}

flowbinding-viewpager/src/androidTest/java/reactivecircus/flowbinding/viewpager/ViewPagerPageSelectedFlowTest.kt

@@ -0,0 +1,78 @@
+package reactivecircus.flowbinding.viewpager
+
+import androidx.test.filters.LargeTest
+import androidx.test.internal.runner.junit4.statement.UiThreadStatement.runOnUiThread
+import androidx.viewpager.widget.ViewPager
+import org.amshove.kluent.shouldEqual
+import org.junit.Test
+import reactivecircus.blueprint.testing.action.swipeLeftOnView
+import reactivecircus.blueprint.testing.action.swipeRightOnView
+import reactivecircus.flowbinding.testing.FlowRecorder
+import reactivecircus.flowbinding.testing.launchTest
+import reactivecircus.flowbinding.testing.recordWith
+import reactivecircus.flowbinding.viewpager.fixtures.ViewPagerFragment
+import reactivecircus.flowbinding.viewpager.test.R
+
+@LargeTest
+class ViewPagerPageSelectedFlowTest {
+
+    @Test
+    fun pageSelections_swipe() {
+        launchTest<ViewPagerFragment> {
+            val recorder = FlowRecorder<Int>(testScope)
+            getViewById<ViewPager>(R.id.viewPager).pageSelections().recordWith(recorder)
+
+            recorder.assertNoMoreValues()
+
+            swipeLeftOnView(R.id.viewPager)
+            recorder.takeValue() shouldEqual 1
+            recorder.assertNoMoreValues()
+
+            cancelTestScope()
+
+            swipeRightOnView(R.id.viewPager)
+            recorder.assertNoMoreValues()
+        }
+    }
+
+    @Test
+    fun pageSelections_programmatic() {
+        launchTest<ViewPagerFragment> {
+            val recorder = FlowRecorder<Int>(testScope)
+            val viewPager = getViewById<ViewPager>(R.id.viewPager)
+            viewPager.pageSelections().recordWith(recorder)
+
+            recorder.assertNoMoreValues()
+
+            runOnUiThread { viewPager.currentItem = 1 }
+            recorder.takeValue() shouldEqual 1
+            recorder.assertNoMoreValues()
+
+            cancelTestScope()
+
+            runOnUiThread { viewPager.currentItem = 0 }
+            recorder.assertNoMoreValues()
+        }
+    }
+
+    @Test
+    fun pageSelections_emitImmediately() {
+        launchTest<ViewPagerFragment> {
+            val recorder = FlowRecorder<Int>(testScope)
+            val viewPager = getViewById<ViewPager>(R.id.viewPager)
+            viewPager.pageSelections(emitImmediately = true).recordWith(recorder)
+
+            recorder.takeValue() shouldEqual 0
+            recorder.assertNoMoreValues()
+
+            runOnUiThread { viewPager.currentItem = 1 }
+            recorder.takeValue() shouldEqual 1
+            recorder.assertNoMoreValues()
+
+            cancelTestScope()
+
+            runOnUiThread { viewPager.currentItem = 0 }
+            recorder.assertNoMoreValues()
+        }
+    }
+}

flowbinding-viewpager/src/main/AndroidManifest.xml

@@ -0,0 +1 @@
+<manifest package="reactivecircus.flowbinding.viewpager" />