snap, PiP

app/src/main/AndroidManifest.xml

@@ -67,8 +67,10 @@
             android:name=".receiver.ReceiverPlaybackActivity"
             android:exported="false"
             android:launchMode="singleTop"
+            android:resizeableActivity="true"
+            android:supportsPictureInPicture="true"
             android:theme="@style/Theme.AndroidCast.Fullscreen"
-            android:configChanges="orientation|screenSize|screenLayout|keyboardHidden" />
+            android:configChanges="orientation|screenSize|screenLayout|smallestScreenSize|keyboardHidden|density" />
 
         <service
             android:name=".sender.ScreenCastService"

app/src/main/java/com/foxx/androidcast/PermissionHelper.java

@@ -18,6 +18,7 @@ import java.util.List;
 /** Requests and explains runtime permissions for LAN cast. */
 public final class PermissionHelper {
     public static final int REQUEST_CODE = 1001;
+    public static final int REQUEST_RECEIVER_PLAYBACK = 1002;
 
     public static final class PermissionItem {
         public final String permission;
@@ -115,9 +116,47 @@ public final class PermissionHelper {
         return arr;
     }
 
-    private static void openAppSettings(Activity activity) {
+    public static void openAppSettings(Activity activity) {
         Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
         intent.setData(Uri.fromParts("package", activity.getPackageName(), null));
         activity.startActivity(intent);
     }
+
+    /** Permissions needed before receiver cast / PiP (notifications for foreground service). */
+    public static boolean hasReceiverPlaybackReady(Activity activity) {
+        return missingForReceiverPlayback(activity).isEmpty();
+    }
+
+    public static void remindForReceiverPlayback(Activity activity) {
+        List<PermissionItem> missing = missingForReceiverPlayback(activity);
+        if (missing.isEmpty()) {
+            return;
+        }
+        StringBuilder body = new StringBuilder(activity.getString(R.string.pip_permissions_hint));
+        body.append("\n\n");
+        for (PermissionItem item : missing) {
+            body.append("• ").append(item.label).append('\n');
+        }
+        new AlertDialog.Builder(activity)
+                .setTitle(R.string.permissions_missing_title)
+                .setMessage(body.toString().trim())
+                .setPositiveButton(R.string.permissions_grant, (d, w) ->
+                        ActivityCompat.requestPermissions(activity,
+                                permissionsOnly(missing), REQUEST_RECEIVER_PLAYBACK))
+                .setNeutralButton(R.string.permissions_app_settings, (d, w) -> openAppSettings(activity))
+                .setNegativeButton(android.R.string.cancel, null)
+                .show();
+    }
+
+    private static List<PermissionItem> missingForReceiverPlayback(Activity activity) {
+        List<PermissionItem> needed = new ArrayList<>();
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            if (ContextCompat.checkSelfPermission(activity, Manifest.permission.POST_NOTIFICATIONS)
+                    != PackageManager.PERMISSION_GRANTED) {
+                needed.add(new PermissionItem(Manifest.permission.POST_NOTIFICATIONS,
+                        activity.getString(R.string.permission_notifications_cast), true));
+            }
+        }
+        return needed;
+    }
 }

app/src/main/java/com/foxx/androidcast/PictureInPictureHelper.java

@@ -0,0 +1,101 @@
+package com.foxx.androidcast;
+
+import android.app.Activity;
+import android.app.AppOpsManager;
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.net.Uri;
+import android.os.Build;
+import android.util.Rational;
+
+import androidx.annotation.NonNull;
+import androidx.appcompat.app.AlertDialog;
+
+import android.app.PictureInPictureParams;
+
+/**
+ * Picture-in-picture for receiver playback (API 26+). No runtime permission; user can disable PiP per app.
+ */
+public final class PictureInPictureHelper {
+    private PictureInPictureHelper() {}
+
+    public static boolean isSupported() {
+        return Build.VERSION.SDK_INT >= Build.VERSION_CODES.O;
+    }
+
+    /** Whether the app is allowed to enter PiP (system / user app-ops). */
+    public static boolean isAllowedForApp(@NonNull Context context) {
+        if (!isSupported()) {
+            return false;
+        }
+        PackageManager pm = context.getPackageManager();
+        if (!pm.hasSystemFeature(PackageManager.FEATURE_PICTURE_IN_PICTURE)) {
+            return false;
+        }
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            AppOpsManager appOps = (AppOpsManager) context.getSystemService(Context.APP_OPS_SERVICE);
+            if (appOps == null) {
+                return true;
+            }
+            int mode = appOps.unsafeCheckOpNoThrow(AppOpsManager.OPSTR_PICTURE_IN_PICTURE,
+                    android.os.Process.myUid(), context.getPackageName());
+            return mode == AppOpsManager.MODE_ALLOWED;
+        }
+        return true;
+    }
+
+    public static PictureInPictureParams buildParams(int videoWidth, int videoHeight) {
+        PictureInPictureParams.Builder builder = new PictureInPictureParams.Builder()
+                .setAspectRatio(aspectRatio(videoWidth, videoHeight));
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+            builder.setAutoEnterEnabled(true);
+            builder.setSeamlessResizeEnabled(true);
+        }
+        return builder.build();
+    }
+
+    public static void applyParams(@NonNull Activity activity, int videoWidth, int videoHeight) {
+        if (!isSupported()) {
+            return;
+        }
+        activity.setPictureInPictureParams(buildParams(videoWidth, videoHeight));
+    }
+
+    public static boolean enter(@NonNull Activity activity, int videoWidth, int videoHeight) {
+        if (!isSupported() || !isAllowedForApp(activity)) {
+            return false;
+        }
+        try {
+            return activity.enterPictureInPictureMode(buildParams(videoWidth, videoHeight));
+        } catch (IllegalStateException e) {
+            return false;
+        }
+    }
+
+    public static void showEnableInSettingsDialog(@NonNull Activity activity) {
+        new AlertDialog.Builder(activity)
+                .setTitle(R.string.pip_disabled_title)
+                .setMessage(R.string.pip_disabled_message)
+                .setPositiveButton(R.string.permissions_app_settings, (d, w) -> openPipSettings(activity))
+                .setNegativeButton(android.R.string.cancel, null)
+                .show();
+    }
+
+    public static void openPipSettings(@NonNull Activity activity) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            Intent intent = new Intent("android.settings.APP_PICTURE_IN_PICTURE_SETTINGS",
+                    Uri.fromParts("package", activity.getPackageName(), null));
+            activity.startActivity(intent);
+        } else {
+            PermissionHelper.openAppSettings(activity);
+        }
+    }
+
+    private static Rational aspectRatio(int width, int height) {
+        if (width > 0 && height > 0) {
+            return new Rational(width, height);
+        }
+        return new Rational(16, 9);
+    }
+}

app/src/main/java/com/foxx/androidcast/receiver/ReceiverPlaybackActivity.java

@@ -10,6 +10,8 @@ import android.os.Handler;
 import android.os.IBinder;
 import android.os.Looper;
 import android.os.RemoteException;
+import android.widget.ImageButton;
+import android.widget.Toast;
 import android.graphics.SurfaceTexture;
 import android.view.Surface;
 import android.view.TextureView;
@@ -26,6 +28,8 @@ import com.foxx.androidcast.AppPreferences;
 import com.foxx.androidcast.CastSettings;
 import com.foxx.androidcast.DrawerHostActivity;
 import com.foxx.androidcast.CastThemeHelper;
+import com.foxx.androidcast.PermissionHelper;
+import com.foxx.androidcast.PictureInPictureHelper;
 import com.foxx.androidcast.ICastReceiverService;
 import com.foxx.androidcast.ICastStatusCallback;
 import com.foxx.androidcast.R;
@@ -53,7 +57,11 @@ public class ReceiverPlaybackActivity extends DrawerHostActivity {
     private TextView diagnosticsText;
     private ImageView robotView;
     private TextView awaitingMessage;
+    private ImageButton pipButton;
     private final Handler mainHandler = new Handler(Looper.getMainLooper());
+    /** Sender connected or actively streaming — PiP allowed after permissions. */
+    private boolean castSessionActive;
+    private boolean inPictureInPicture;
     private SurfaceTexture surfaceTexture;
     private int videoWidth;
     private int videoHeight;
@@ -70,7 +78,10 @@ public class ReceiverPlaybackActivity extends DrawerHostActivity {
 
         @Override
         public void onAuthenticated(String senderName) {
-            runOnUiThread(() -> showAwaitingOverlay(R.string.playback_awaiting_stream));
+            runOnUiThread(() -> {
+                onCastSessionStarted();
+                showAwaitingOverlay(R.string.playback_awaiting_stream);
+            });
         }
 
         @Override
@@ -104,7 +115,10 @@ public class ReceiverPlaybackActivity extends DrawerHostActivity {
 
         @Override
         public void onDisconnected() {
-            runOnUiThread(() -> onStreamLost());
+            runOnUiThread(() -> {
+                onCastSessionEnded();
+                onStreamLost();
+            });
         }
     };
 
@@ -164,8 +178,13 @@ public class ReceiverPlaybackActivity extends DrawerHostActivity {
         diagnosticsText = findViewById(R.id.text_diagnostics);
         robotView = findViewById(R.id.image_robot);
         awaitingMessage = findViewById(R.id.text_awaiting_message);
+        pipButton = findViewById(R.id.button_pip);
+        if (pipButton != null) {
+            pipButton.setOnClickListener(v -> tryEnterPictureInPicture());
+        }
         textureView.setSurfaceTextureListener(surfaceListener);
         applyAspectRatio();
+        updatePipUi();
 
         if (getIntent().getBooleanExtra(EXTRA_AUTO_START_LISTENING, false)) {
             startListeningService();
@@ -214,11 +233,38 @@ public class ReceiverPlaybackActivity extends DrawerHostActivity {
     @Override
     protected void onResume() {
         super.onResume();
+        if (!inPictureInPicture) {
+            PermissionHelper.remindForReceiverPlayback(this);
+        }
         if (awaitingOverlay != null && awaitingOverlay.getVisibility() == View.VISIBLE) {
             startRobotAnimation();
         }
         mainHandler.post(diagnosticsRefresh);
         updateDiagnosticsVisibility();
+        updatePipUi();
+    }
+
+    @Override
+    public void onUserLeaveHint() {
+        super.onUserLeaveHint();
+        if (castSessionActive && PermissionHelper.hasReceiverPlaybackReady(this)) {
+            tryEnterPictureInPicture();
+        }
+    }
+
+    @Override
+    public void onPictureInPictureModeChanged(boolean isInPictureInPictureMode) {
+        super.onPictureInPictureModeChanged(isInPictureInPictureMode);
+        inPictureInPicture = isInPictureInPictureMode;
+        applyPipChromeVisibility();
+    }
+
+    @Override
+    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
+        if (requestCode == PermissionHelper.REQUEST_RECEIVER_PLAYBACK) {
+            updatePipUi();
+        }
     }
 
     @Override
@@ -357,6 +403,9 @@ public class ReceiverPlaybackActivity extends DrawerHostActivity {
         }
         videoWidth = width;
         videoHeight = height;
+        if (castSessionActive && PermissionHelper.hasReceiverPlaybackReady(this)) {
+            PictureInPictureHelper.applyParams(this, videoWidth, videoHeight);
+        }
         applyAspectRatio();
         applyTextureFitCenter();
         if (surfaceTexture != null) {
@@ -453,8 +502,81 @@ public class ReceiverPlaybackActivity extends DrawerHostActivity {
     @Override
     public void onWindowFocusChanged(boolean hasFocus) {
         super.onWindowFocusChanged(hasFocus);
-        if (hasFocus) {
+        if (hasFocus && !inPictureInPicture) {
             applyFullscreen();
         }
     }
+
+    private void onCastSessionStarted() {
+        castSessionActive = true;
+        PermissionHelper.remindForReceiverPlayback(this);
+        updatePipUi();
+    }
+
+    private void onCastSessionEnded() {
+        castSessionActive = false;
+        updatePipUi();
+    }
+
+    private void updatePipUi() {
+        if (pipButton == null) {
+            return;
+        }
+        boolean show = castSessionActive && PictureInPictureHelper.isSupported()
+                && PermissionHelper.hasReceiverPlaybackReady(this);
+        pipButton.setVisibility(show ? View.VISIBLE : View.GONE);
+        if (show) {
+            pipButton.bringToFront();
+        }
+    }
+
+    private void tryEnterPictureInPicture() {
+        if (!castSessionActive) {
+            return;
+        }
+        if (!PermissionHelper.hasReceiverPlaybackReady(this)) {
+            PermissionHelper.remindForReceiverPlayback(this);
+            return;
+        }
+        if (!PictureInPictureHelper.isSupported()) {
+            Toast.makeText(this, R.string.pip_unavailable, Toast.LENGTH_SHORT).show();
+            return;
+        }
+        if (!PictureInPictureHelper.isAllowedForApp(this)) {
+            PictureInPictureHelper.showEnableInSettingsDialog(this);
+            return;
+        }
+        if (!PictureInPictureHelper.enter(this, videoWidth, videoHeight)) {
+            PictureInPictureHelper.showEnableInSettingsDialog(this);
+        }
+    }
+
+    private void applyPipChromeVisibility() {
+        View handle = findViewById(R.id.settings_drawer_handle);
+        if (handle != null) {
+            handle.setVisibility(inPictureInPicture ? View.GONE : View.VISIBLE);
+        }
+        if (pipButton != null) {
+            pipButton.setVisibility(inPictureInPicture || !castSessionActive ? View.GONE : View.VISIBLE);
+        }
+        if (inPictureInPicture) {
+            if (diagnosticsText != null) {
+                diagnosticsText.setVisibility(View.GONE);
+            }
+            if (awaitingOverlay != null && streamRendering) {
+                awaitingOverlay.setVisibility(View.GONE);
+            }
+            stopRobotAnimation();
+        } else {
+            updateDiagnosticsVisibility();
+            if (!streamRendering && awaitingOverlay != null
+                    && awaitingOverlay.getVisibility() == View.VISIBLE) {
+                startRobotAnimation();
+            }
+            if (castSessionActive) {
+                applyFullscreen();
+            }
+            updatePipUi();
+        }
+    }
 }

app/src/main/res/drawable/ic_picture_in_picture.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="#FFFFFF"
+        android:pathData="M19,7h-8v6h8V7zM21,3H3C1.9,3 1,3.9 1,5v14c0,1.1 0.9,2 2,2h18c1.1,0 2,-0.9 2,-2V5C23,3.9 22.1,3 21,3zM21,19H3V5h18V19z" />
+</vector>

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

@@ -34,4 +34,16 @@
         layout="@layout/overlay_cast_diagnostics"
         android:layout_width="match_parent"
         android:layout_height="match_parent" />
+
+    <ImageButton
+        android:id="@+id/button_pip"
+        android:layout_width="48dp"
+        android:layout_height="48dp"
+        android:layout_gravity="top|end"
+        android:layout_margin="16dp"
+        android:background="?attr/selectableItemBackgroundBorderless"
+        android:contentDescription="@string/pip_enter"
+        android:padding="8dp"
+        android:src="@drawable/ic_picture_in_picture"
+        android:visibility="gone" />
 </FrameLayout>

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

@@ -195,4 +195,10 @@
     <string name="codec_speex">Speex</string>
     <string name="codec_opus">Opus</string>
     <string name="codec_audio_auto">AUTO (AAC)</string>
+    <string name="pip_enter">Картинка в картинке</string>
+    <string name="pip_unavailable">Режим «картинка в картинке» недоступен на этом устройстве</string>
+    <string name="pip_disabled_title">Картинка в картинке отключена</string>
+    <string name="pip_disabled_message">Разрешите картинку в картинке для Android Cast в настройках системы.</string>
+    <string name="pip_permissions_hint">Уведомления нужны, чтобы приёмник оставался активным при трансляции в фоне.</string>
+    <string name="permission_notifications_cast">Уведомления (статус трансляции)</string>
 </resources>

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

@@ -195,4 +195,10 @@
     <string name="codec_speex">Speex</string>
     <string name="codec_opus">Opus</string>
     <string name="codec_audio_auto">AUTO (AAC)</string>
+    <string name="pip_enter">Picture-in-picture</string>
+    <string name="pip_unavailable">Picture-in-picture is not available on this device</string>
+    <string name="pip_disabled_title">Picture-in-picture disabled</string>
+    <string name="pip_disabled_message">Allow picture-in-picture for Android Cast in system settings, then try again.</string>
+    <string name="pip_permissions_hint">Notifications keep the receiver visible while casting in the background.</string>
+    <string name="permission_notifications_cast">Notifications (cast status)</string>
 </resources>