feat: Adding Flow support for getting place selection events.

Change-Id: I51108f10b4576a016dd258d2101e8f64a0af02bd

app/build.gradle

@@ -57,6 +57,7 @@ android {
     }
 
     kotlinOptions {
+        freeCompilerArgs += ["-Xopt-in=kotlin.RequiresOptIn"]
         jvmTarget = JavaVersion.VERSION_1_8.toString()
     }
 }

app/src/main/AndroidManifest.xml

@@ -26,15 +26,18 @@
         android:supportsRtl="true"
         android:name=".DemoApplication"
         android:theme="@style/AppTheme">
-        <activity
-            android:name=".PlacesSearchDemoActivity"
-            android:exported="true"
-            android:label="@string/app_name"
-            android:theme="@style/Theme.AppCompat.DayNight.NoActionBar" >
+        <activity android:name=".DemoActivity"
+            android:label="@string/app_name" >
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
+
+        <activity android:name=".AutocompleteDemoActivity" />
+
+        <activity
+            android:name=".PlacesSearchDemoActivity"
+            android:theme="@style/Theme.AppCompat.DayNight.NoActionBar" />
     </application>
 </manifest>

app/src/main/java/com/google/places/android/ktx/demo/AutocompleteDemoActivity.kt

@@ -0,0 +1,47 @@
+package com.google.places.android.ktx.demo
+
+import android.os.Bundle
+import android.widget.Toast
+import androidx.appcompat.app.AppCompatActivity
+import androidx.lifecycle.lifecycleScope
+import com.google.android.libraries.places.api.model.Place
+import com.google.android.libraries.places.ktx.widget.PlaceSelectionError
+import com.google.android.libraries.places.ktx.widget.PlaceSelectionSuccess
+import com.google.android.libraries.places.ktx.widget.placeSelectionEvents
+import com.google.android.libraries.places.widget.AutocompleteSupportFragment
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.collect
+
+class AutocompleteDemoActivity : AppCompatActivity() {
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_autocomplete)
+
+        val autocompleteFragment =
+            supportFragmentManager.findFragmentById(R.id.autocomplete_fragment)
+                as AutocompleteSupportFragment
+
+        // Specify the types of place data to return.
+        autocompleteFragment.setPlaceFields(listOf(Place.Field.ID, Place.Field.NAME))
+
+        // Listen to place selection events
+        lifecycleScope.launchWhenCreated {
+            autocompleteFragment.placeSelectionEvents().collect { event ->
+                when (event) {
+                    is PlaceSelectionSuccess -> Toast.makeText(
+                        this@AutocompleteDemoActivity,
+                        "Got place '${event.place.name}'",
+                        Toast.LENGTH_SHORT
+                    ).show()
+                    is PlaceSelectionError -> Toast.makeText(
+                        this@AutocompleteDemoActivity,
+                        "Failed to get place '${event.status.statusMessage}'",
+                        Toast.LENGTH_SHORT
+                    ).show()
+                }
+            }
+        }
+    }
+}

app/src/main/java/com/google/places/android/ktx/demo/Demo.kt

@@ -0,0 +1,21 @@
+package com.google.places.android.ktx.demo
+
+import android.app.Activity
+import androidx.annotation.StringRes
+
+enum class Demo(
+    @StringRes val title: Int,
+    @StringRes val description: Int,
+    val activity: Class<out Activity>
+) {
+    AUTOCOMPLETE_FRAGMENT_DEMO(
+        R.string.autocomplete_fragment_demo_title,
+        R.string.autocomplete_fragment_demo_description,
+        AutocompleteDemoActivity::class.java
+    ),
+    PLACES_SEARCH_DEMO(
+        R.string.places_demo_title,
+        R.string.places_demo_description,
+        PlacesSearchDemoActivity::class.java
+    )
+}

app/src/main/java/com/google/places/android/ktx/demo/DemoActivity.kt

@@ -0,0 +1,61 @@
+package com.google.places.android.ktx.demo
+
+import android.content.Context
+import android.content.Intent
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.AdapterView
+import android.widget.ArrayAdapter
+import android.widget.LinearLayout
+import android.widget.ListView
+import android.widget.TextView
+import androidx.appcompat.app.AppCompatActivity
+
+class DemoActivity : AppCompatActivity() {
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+
+        val listView = ListView(this).also {
+            it.layoutParams = ViewGroup.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT,
+                ViewGroup.LayoutParams.MATCH_PARENT
+            )
+            it.adapter = DemoAdapter(this, Demo.values())
+            it.onItemClickListener = AdapterView.OnItemClickListener { parent, _, position, _ ->
+                val demo = parent.adapter.getItem(position) as? Demo
+                demo?.let {
+                    startActivity(Intent(this, demo.activity))
+                }
+            }
+        }
+        setContentView(listView)
+    }
+
+    private class DemoAdapter(context: Context, demos: Array<Demo>) :
+        ArrayAdapter<Demo>(context, R.layout.item_demo, demos) {
+
+        override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
+            val demoView = (convertView as? DemoItemView) ?: DemoItemView(context)
+            return demoView.also {
+                val demo = getItem(position)
+                it.title.setText(demo?.title ?: 0)
+                it.description.setText(demo?.description ?: 0)
+            }
+        }
+    }
+
+    private class DemoItemView(context: Context) : LinearLayout(context) {
+
+        val title: TextView by lazy { findViewById<TextView>(R.id.textViewTitle) }
+
+        val description: TextView by lazy { findViewById<TextView>(R.id.textViewDescription) }
+
+        init {
+            LayoutInflater.from(context)
+                .inflate(R.layout.item_demo, this)
+        }
+    }
+}

app/src/main/java/com/google/places/android/ktx/demo/DemoApplication.kt

@@ -22,6 +22,13 @@ import dagger.hilt.android.HiltAndroidApp
 class DemoApplication : Application() {
     override fun onCreate() {
         super.onCreate()
+
+        // Initialize the Places SDK. Note that the string value of `maps_api_key` will be generated
+        // at build-time (see app/build.gradle). The technique used here allows you to provide your
+        // API key such that the key is not checked in source control.
+        //
+        // See API Key Best Practices for more information on how to secure your API key:
+        // https://developers.google.com/maps/api-key-best-practices
         Places.initialize(this, BuildConfig.PLACES_API_KEY)
     }
 }

app/src/main/java/com/google/places/android/ktx/demo/PlacesSearchDemoActivity.kt

@@ -67,13 +67,13 @@ class PlacesSearchDemoActivity : AppCompatActivity() {
     override fun onCreateOptionsMenu(menu: Menu): Boolean {
         menuInflater.inflate(R.menu.menu, menu)
         val searchView = menu.findItem(R.id.search).actionView as SearchView
-        searchView.also {
-            it.queryHint = getString(R.string.search_a_place)
-            it.isIconifiedByDefault = false
-            it.isFocusable = true
-            it.isIconified = false
-            it.requestFocusFromTouch()
-            it.setOnQueryTextListener(object : SearchView.OnQueryTextListener {
+        searchView.apply {
+            queryHint = getString(R.string.search_a_place)
+            isIconifiedByDefault = false
+            isFocusable = true
+            isIconified = false
+            requestFocusFromTouch()
+            setOnQueryTextListener(object : SearchView.OnQueryTextListener {
                 override fun onQueryTextSubmit(query: String): Boolean {
                     return false
                 }
@@ -88,11 +88,16 @@ class PlacesSearchDemoActivity : AppCompatActivity() {
     }
 
     private fun initRecyclerView() {
-        findViewById<RecyclerView>(R.id.recycler_view).also {
-            val layoutManager = LinearLayoutManager(this)
-            it.layoutManager = layoutManager
-            it.adapter = adapter
-            it.addItemDecoration(DividerItemDecoration(this, layoutManager.orientation))
+        val linearLayoutManager = LinearLayoutManager(this)
+        findViewById<RecyclerView>(R.id.recycler_view).apply {
+            layoutManager = linearLayoutManager
+            adapter = adapter
+            addItemDecoration(
+                DividerItemDecoration(
+                    this@PlacesSearchDemoActivity,
+                    linearLayoutManager.orientation
+                )
+            )
         }
     }
 

app/src/main/java/com/google/places/android/ktx/demo/PlacesSearchViewModel.kt

@@ -26,6 +26,7 @@ import com.google.android.libraries.places.api.model.TypeFilter
 import com.google.android.libraries.places.api.net.FindAutocompletePredictionsRequest
 import com.google.android.libraries.places.api.net.PlacesClient
 import com.google.android.libraries.places.ktx.api.net.awaitFindAutocompletePredictions
+import com.google.android.libraries.places.ktx.api.net.findAutocompletePredictionsRequest
 import kotlinx.coroutines.CoroutineExceptionHandler
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.delay
@@ -48,20 +49,23 @@ class PlacesSearchViewModel @ViewModelInject constructor(
             _events.value = PlacesSearchEventError(throwable)
         }
         searchJob = viewModelScope.launch(handler) {
+            // Add delay so that network call is performed only after there is a 300 ms pause in the
+            // search query. This prevents network calls from being invoked if the user is still
+            // typing.
             delay(300)
 
             val bias: LocationBias = RectangularBounds.newInstance(
                 LatLng(37.7576948, -122.4727051), // SW lat, lng
                 LatLng(37.808300, -122.391338) // NE lat, lng
             )
 
-            val request = FindAutocompletePredictionsRequest
-                .builder()
-                .setLocationBias(bias)
-                .setTypeFilter(TypeFilter.ESTABLISHMENT)
-                .setQuery(query)
-                .setCountries("US")
-                .build()
+            val request = findAutocompletePredictionsRequest {
+                setLocationBias(bias)
+                setTypeFilter(TypeFilter.ESTABLISHMENT)
+                setQuery(query)
+                setCountries("US")
+            }
+
             val response = placesClient
                 .awaitFindAutocompletePredictions(request)
             _events.value = PlacesSearchEventFound(response.autocompletePredictions)

app/src/main/res/layout/activity_autocomplete.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:orientation="vertical"
+    android:background="@color/colorGray"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <androidx.fragment.app.FragmentContainerView
+        android:id="@+id/autocomplete_fragment"
+        android:background="@android:color/white"
+        android:name="com.google.android.libraries.places.widget.AutocompleteSupportFragment"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content" />
+
+</LinearLayout>

app/src/main/res/values/colors.xml

@@ -19,4 +19,5 @@
     <color name="colorPrimary">#008577</color>
     <color name="colorPrimaryDark">#00574B</color>
     <color name="colorAccent">#D81B60</color>
+    <color name="colorGray">#dedede</color>
 </resources>

app/src/main/res/values/strings.xml

@@ -16,7 +16,13 @@
 
 <resources>
     <string name="app_name">Android Places KTX Demo</string>
-    <string name="programmatic_place_predictions_instructions">"  This activity demonstrates as-you-type programmatic place predictions. Tap on the search icon on the toolbar and search for a place."</string>
+    <string name="programmatic_place_predictions_instructions">This activity demonstrates as-you-type programmatic place predictions. Tap on the search icon on the toolbar and search for a place.</string>
     <string name="search">Search</string>
     <string name="search_a_place">Search a Place</string>
+
+    <string name="places_demo_title">Places Search Demo</string>
+    <string name="places_demo_description">Demonstrates usages of Places KTX coroutines and DSL builder features.</string>
+
+    <string name="autocomplete_fragment_demo_title">Autocomplete Fragment Demo</string>
+    <string name="autocomplete_fragment_demo_description">Demonstrates using AutocompleteSupportFragment and placeSelectionEvents() to use Kotlin Flow.</string>
 </resources>

places-ktx/build.gradle

@@ -38,7 +38,8 @@ android {
 dependencies {
     implementation deps.kotlin
     implementation deps.kotlinxCoroutines.android
-    implementation deps.kotlinxCoroutines.playServices
+    implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.2.0"
+    api deps.kotlinxCoroutines.playServices
     api deps.places
 
     // Tests

places-ktx/src/main/java/com/google/android/libraries/places/ktx/widget/AutocompleteSupportFragment.kt

@@ -0,0 +1,29 @@
+package com.google.android.libraries.places.ktx.widget
+
+import com.google.android.gms.common.api.Status
+import com.google.android.libraries.places.api.model.Place
+import com.google.android.libraries.places.widget.AutocompleteSupportFragment
+import com.google.android.libraries.places.widget.listener.PlaceSelectionListener
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.callbackFlow
+
+sealed class PlaceSelectionResult
+
+data class PlaceSelectionSuccess(val place: Place) : PlaceSelectionResult()
+
+data class PlaceSelectionError(val status: Status) : PlaceSelectionResult()
+
+@ExperimentalCoroutinesApi
+fun AutocompleteSupportFragment.placeSelectionEvents() : Flow<PlaceSelectionResult> =
+    callbackFlow {
+        this@placeSelectionEvents.setOnPlaceSelectedListener(object : PlaceSelectionListener {
+            override fun onPlaceSelected(place: Place) {
+                offer(PlaceSelectionSuccess(place))
+            }
+
+            override fun onError(status: Status) {
+                offer(PlaceSelectionError(status))
+            }
+        })
+    }