android: Add Picture in Picture mode

src/android/app/src/main/AndroidManifest.xml

@@ -60,6 +60,8 @@ SPDX-License-Identifier: GPL-3.0-or-later
             android:theme="@style/Theme.Yuzu.Main"
             android:launchMode="singleTop"
             android:screenOrientation="userLandscape"
+            android:supportsPictureInPicture="true"
+            android:configChanges="orientation|screenSize|smallestScreenSize|screenLayout|uiMode"
             android:exported="true">
 
             <intent-filter>

src/android/app/src/main/java/org/yuzu/yuzu_emu/activities/EmulationActivity.kt

@@ -4,15 +4,22 @@
 package org.yuzu.yuzu_emu.activities
 
 import android.app.Activity
+import android.app.PendingIntent
+import android.app.PictureInPictureParams
+import android.app.RemoteAction
+import android.content.BroadcastReceiver
 import android.content.Context
 import android.content.Intent
+import android.content.IntentFilter
 import android.content.res.Configuration
 import android.graphics.Rect
+import android.graphics.drawable.Icon
 import android.hardware.Sensor
 import android.hardware.SensorEvent
 import android.hardware.SensorEventListener
 import android.hardware.SensorManager
 import android.hardware.display.DisplayManager
+import android.os.Build
 import android.os.Bundle
 import android.view.Display
 import android.view.InputDevice
@@ -60,6 +67,10 @@ class EmulationActivity : AppCompatActivity(), SensorEventListener {
     private var motionTimestamp: Long = 0
     private var flipMotionOrientation: Boolean = false
 
+    private val actionPause = "ACTION_EMULATOR_PAUSE"
+    private val actionPlay = "ACTION_EMULATOR_PLAY"
+    private lateinit var pictureInPictureParamsBuilder : PictureInPictureParams.Builder
+
     private lateinit var game: Game
 
     private val settingsViewModel: SettingsViewModel by viewModels()
@@ -88,6 +99,9 @@ class EmulationActivity : AppCompatActivity(), SensorEventListener {
         // Set these options now so that the SurfaceView the game renders into is the right size.
         enableFullscreenImmersive()
 
+        pictureInPictureParamsBuilder = getPictureInPictureBuilder()
+        setPictureInPictureParams(pictureInPictureParamsBuilder.build())
+
         setContentView(R.layout.activity_emulation)
         window.decorView.setBackgroundColor(getColor(android.R.color.black))
 
@@ -161,6 +175,12 @@ class EmulationActivity : AppCompatActivity(), SensorEventListener {
         stopMotionSensorListener()
     }
 
+    override fun onUserLeaveHint() {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.S && !isInPictureInPictureMode) {
+            enterPictureInPictureMode(pictureInPictureParamsBuilder.build())
+        }
+    }
+
     override fun onNewIntent(intent: Intent) {
         super.onNewIntent(intent)
         setIntent(intent)
@@ -289,6 +309,61 @@ class EmulationActivity : AppCompatActivity(), SensorEventListener {
         }
     }
 
+    private fun getPictureInPictureBuilder() : PictureInPictureParams.Builder {
+        val pictureInPictureParamsBuilder = PictureInPictureParams.Builder()
+
+        val pictureInPictureActions : MutableList<RemoteAction> = mutableListOf()
+        val pendingFlags = PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
+
+        val pauseIcon = Icon.createWithResource(this, R.drawable.ic_pause)
+        val pausePendingIntent = PendingIntent.getBroadcast(this, R.drawable.ic_pause, Intent(actionPause), pendingFlags)
+        val pauseRemoteAction = RemoteAction(pauseIcon, getString(R.string.pause), getString(R.string.pause), pausePendingIntent)
+        pictureInPictureActions.add(pauseRemoteAction)
+
+        val playIcon = Icon.createWithResource(this, R.drawable.ic_play)
+        val playPendingIntent = PendingIntent.getBroadcast(this, R.drawable.ic_play, Intent(actionPlay), pendingFlags)
+        val playRemoteAction = RemoteAction(playIcon, getString(R.string.play), getString(R.string.play), playPendingIntent)
+        pictureInPictureActions.add(playRemoteAction)
+
+        pictureInPictureParamsBuilder.setActions(pictureInPictureActions)
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+            pictureInPictureParamsBuilder.setAutoEnterEnabled(true)
+        }
+
+        setPictureInPictureParams(pictureInPictureParamsBuilder.build())
+
+        return pictureInPictureParamsBuilder
+    }
+
+    private var pictureInPictureReceiver = object : BroadcastReceiver() {
+        override fun onReceive(context : Context?, intent : Intent) {
+            if (intent.action == actionPause) {
+                emulationFragment?.onPictureInPicturePause()
+            }
+            if (intent.action == actionPlay) {
+                emulationFragment?.onPictureInPicturePlay()
+            }
+        }
+    }
+
+    override fun onPictureInPictureModeChanged(isInPictureInPictureMode: Boolean, newConfig: Configuration) {
+        super.onPictureInPictureModeChanged(isInPictureInPictureMode, newConfig)
+        if (isInPictureInPictureMode) {
+            IntentFilter().apply {
+                addAction(actionPause)
+                addAction(actionPlay)
+            }.also {
+                registerReceiver(pictureInPictureReceiver, it)
+            }
+            emulationFragment?.onPictureInPictureEnter()
+        } else {
+            try {
+                unregisterReceiver(pictureInPictureReceiver)
+            } catch (ignored : Exception) { }
+            emulationFragment?.onPictureInPictureLeave()
+        }
+    }
+
     private fun startMotionSensorListener() {
         val sensorManager = this.getSystemService(Context.SENSOR_SERVICE) as SensorManager
         val gyroSensor = sensorManager.getDefaultSensor(Sensor.TYPE_GYROSCOPE)

src/android/app/src/main/java/org/yuzu/yuzu_emu/fragments/EmulationFragment.kt

@@ -23,6 +23,7 @@ import androidx.core.content.res.ResourcesCompat
 import androidx.core.graphics.Insets
 import androidx.core.view.ViewCompat
 import androidx.core.view.WindowInsetsCompat
+import androidx.core.view.isVisible
 import androidx.core.view.updatePadding
 import androidx.fragment.app.Fragment
 import androidx.preference.PreferenceManager
@@ -178,6 +179,30 @@ class EmulationFragment : Fragment(), SurfaceHolder.Callback {
         super.onDetach()
     }
 
+    fun onPictureInPictureEnter() {
+        if (EmulationMenuSettings.showOverlay) {
+            binding.surfaceInputOverlay.post { binding.surfaceInputOverlay.isVisible = false }
+        }
+    }
+
+    fun onPictureInPicturePause() {
+        if (!emulationState.isPaused) {
+            emulationState.pause()
+        }
+    }
+
+    fun onPictureInPicturePlay() {
+        if (emulationState.isPaused) {
+            emulationState.run(false)
+        }
+    }
+
+    fun onPictureInPictureLeave() {
+        if (EmulationMenuSettings.showOverlay) {
+            binding.surfaceInputOverlay.post { binding.surfaceInputOverlay.isVisible = true }
+        }
+    }
+
     private fun refreshInputOverlay() {
         binding.surfaceInputOverlay.refreshControls()
     }

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

@@ -356,6 +356,10 @@
     <string name="use_black_backgrounds">Black backgrounds</string>
     <string name="use_black_backgrounds_description">When using the dark theme, apply black backgrounds.</string>
 
+    <!-- Picture-In-Picture -->
+    <string name="pause">Pause</string>
+    <string name="play">Play</string>
+
     <!-- Licenses screen strings -->
     <string name="licenses">Licenses</string>
     <string name="license_fidelityfx_fsr" translatable="false">FidelityFX-FSR</string>