Implement initial support for foldables in calling.

app/build.gradle

@@ -376,6 +376,7 @@ dependencies {
     implementation ('androidx.appcompat:appcompat:1.2.0') {
         force = true
     }
+    implementation "androidx.window:window:1.0.0-alpha09"
     implementation 'androidx.recyclerview:recyclerview:1.1.0'
     implementation 'com.google.android.material:material:1.3.0'
     implementation 'androidx.legacy:legacy-support-v13:1.0.0'

app/proguard/proguard.cfg

@@ -9,3 +9,5 @@
 
 # Protobuf lite
 -keep class * extends com.google.protobuf.GeneratedMessageLite { *; }
+
+-keep class androidx.window.** { *; }

app/src/main/AndroidManifest.xml

@@ -96,6 +96,7 @@
                  android:label="@string/app_name"
                  android:supportsRtl="true"
                  tools:replace="android:allowBackup"
+                 android:resizeableActivity="true"
                  android:allowBackup="false"
                  android:theme="@style/TextSecure.LightTheme"
                  android:largeHeap="true">
@@ -104,6 +105,9 @@
             android:name="com.google.android.geo.API_KEY"
             android:value="AIzaSyCSx9xea86GwDKGznCAULE9Y5a8b-TfN9U"/>
 
+    <meta-data android:name="android.supports_size_changes"
+               android:value="true" />
+
     <meta-data android:name="com.google.android.gms.version"
                android:value="@integer/google_play_services_version" />
 
@@ -117,16 +121,15 @@
     <activity android:name=".WebRtcCallActivity"
               android:theme="@style/TextSecure.DarkTheme.WebRTCCall"
               android:excludeFromRecents="true"
-              android:screenOrientation="portrait"
               android:supportsPictureInPicture="true"
               android:windowSoftInputMode="stateAlwaysHidden"
               android:configChanges="screenSize|smallestScreenSize|screenLayout|orientation"
               android:taskAffinity=".calling"
+              android:resizeableActivity="true"
               android:launchMode="singleTask"/>
 
     <activity android:name=".messagerequests.CalleeMustAcceptMessageRequestActivity"
               android:theme="@style/TextSecure.DarkNoActionBar"
-              android:screenOrientation="portrait"
               android:noHistory="true"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 

app/src/main/java/org/thoughtcrime/securesms/WebRtcCallActivity.java

@@ -22,8 +22,10 @@ import android.annotation.SuppressLint;
 import android.app.PictureInPictureParams;
 import android.content.Context;
 import android.content.Intent;
+import android.content.pm.ActivityInfo;
 import android.content.pm.PackageManager;
 import android.content.res.Configuration;
+import android.graphics.Rect;
 import android.media.AudioManager;
 import android.os.Build;
 import android.os.Bundle;
@@ -35,11 +37,16 @@ import androidx.annotation.NonNull;
 import androidx.appcompat.app.AlertDialog;
 import androidx.appcompat.app.AppCompatDelegate;
 import androidx.core.content.ContextCompat;
+import androidx.core.util.Consumer;
 import androidx.lifecycle.ViewModelProviders;
+import androidx.window.DisplayFeature;
+import androidx.window.FoldingFeature;
+import androidx.window.WindowLayoutInfo;
 
 import org.greenrobot.eventbus.EventBus;
 import org.greenrobot.eventbus.Subscribe;
 import org.greenrobot.eventbus.ThreadMode;
+import org.signal.core.util.concurrent.SignalExecutors;
 import org.signal.core.util.logging.Log;
 import org.thoughtcrime.securesms.components.TooltipPopup;
 import org.thoughtcrime.securesms.components.sensors.DeviceOrientationMonitor;
@@ -50,6 +57,7 @@ import org.thoughtcrime.securesms.components.webrtc.GroupCallSafetyNumberChangeN
 import org.thoughtcrime.securesms.components.webrtc.WebRtcAudioOutput;
 import org.thoughtcrime.securesms.components.webrtc.WebRtcCallView;
 import org.thoughtcrime.securesms.components.webrtc.WebRtcCallViewModel;
+import org.thoughtcrime.securesms.components.webrtc.WebRtcControls;
 import org.thoughtcrime.securesms.components.webrtc.participantslist.CallParticipantsListDialog;
 import org.thoughtcrime.securesms.conversation.ui.error.SafetyNumberChangeDialog;
 import org.thoughtcrime.securesms.dependencies.ApplicationDependencies;
@@ -70,6 +78,7 @@ import org.whispersystems.libsignal.util.Pair;
 import org.whispersystems.signalservice.api.messages.calls.HangupMessage;
 
 import java.util.List;
+import java.util.Optional;
 
 import static org.thoughtcrime.securesms.components.sensors.Orientation.PORTRAIT_BOTTOM_EDGE;
 
@@ -88,11 +97,13 @@ public class WebRtcCallActivity extends BaseActivity implements SafetyNumberChan
   private CallParticipantsListUpdatePopupWindow participantUpdateWindow;
   private DeviceOrientationMonitor              deviceOrientationMonitor;
 
-  private FullscreenHelper    fullscreenHelper;
+  private FullscreenHelper              fullscreenHelper;
-  private WebRtcCallView      callScreen;
+  private WebRtcCallView                callScreen;
-  private TooltipPopup        videoTooltip;
+  private TooltipPopup                  videoTooltip;
-  private WebRtcCallViewModel viewModel;
+  private WebRtcCallViewModel           viewModel;
-  private boolean             enableVideoIfAvailable;
+  private boolean                       enableVideoIfAvailable;
+  private androidx.window.WindowManager windowManager;
+  private WindowLayoutInfoConsumer      windowLayoutInfoConsumer;
 
   @Override
   protected void attachBaseContext(@NonNull Context newBase) {
@@ -100,6 +111,19 @@ public class WebRtcCallActivity extends BaseActivity implements SafetyNumberChan
     super.attachBaseContext(newBase);
   }
 
+  @Override
+  public void onConfigurationChanged(@NonNull Configuration newConfig) {
+    super.onConfigurationChanged(newConfig);
+
+    if (newConfig.densityDpi >= 480 && getRequestedOrientation() == ActivityInfo.SCREEN_ORIENTATION_PORTRAIT) {
+      viewModel.setIsLandscapeEnabled(true);
+      setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED);
+    } else if (newConfig.densityDpi < 480){
+      viewModel.setIsLandscapeEnabled(false);
+    }
+  }
+
+  @SuppressLint("SourceLockedOrientationActivity")
   @Override
   public void onCreate(Bundle savedInstanceState) {
     Log.i(TAG, "onCreate()");
@@ -107,6 +131,11 @@ public class WebRtcCallActivity extends BaseActivity implements SafetyNumberChan
     getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
     super.onCreate(savedInstanceState);
 
+    boolean isLandscapeEnabled = getResources().getConfiguration().densityDpi >= 480;
+    if (!isLandscapeEnabled) {
+      setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
+    }
+
     requestWindowFeature(Window.FEATURE_NO_TITLE);
     setContentView(R.layout.webrtc_call_activity);
 
@@ -115,12 +144,17 @@ public class WebRtcCallActivity extends BaseActivity implements SafetyNumberChan
     setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);
 
     initializeResources();
-    initializeViewModel();
+    initializeViewModel(isLandscapeEnabled);
 
     processIntent(getIntent());
 
     enableVideoIfAvailable = getIntent().getBooleanExtra(EXTRA_ENABLE_VIDEO_IF_AVAILABLE, false);
     getIntent().removeExtra(EXTRA_ENABLE_VIDEO_IF_AVAILABLE);
+
+    windowManager            = new androidx.window.WindowManager(this);
+    windowLayoutInfoConsumer = new WindowLayoutInfoConsumer(windowManager);
+
+    windowManager.registerLayoutChangeCallback(SignalExecutors.BOUNDED, windowLayoutInfoConsumer);
   }
 
   @Override
@@ -178,6 +212,7 @@ public class WebRtcCallActivity extends BaseActivity implements SafetyNumberChan
   @Override
   protected void onDestroy() {
     super.onDestroy();
+    windowManager.unregisterLayoutChangeCallback(windowLayoutInfoConsumer);
     EventBus.getDefault().unregister(this);
   }
 
@@ -208,8 +243,8 @@ public class WebRtcCallActivity extends BaseActivity implements SafetyNumberChan
   private boolean enterPipModeIfPossible() {
     if (viewModel.canEnterPipMode() && isSystemPipEnabledAndAvailable()) {
       PictureInPictureParams params = new PictureInPictureParams.Builder()
-              .setAspectRatio(new Rational(9, 16))
+          .setAspectRatio(new Rational(9, 16))
-              .build();
+          .build();
       enterPictureInPictureMode(params);
       CallParticipantsListDialog.dismiss(getSupportFragmentManager());
 
@@ -248,13 +283,14 @@ public class WebRtcCallActivity extends BaseActivity implements SafetyNumberChan
     participantUpdateWindow = new CallParticipantsListUpdatePopupWindow(callScreen);
   }
 
-  private void initializeViewModel() {
+  private void initializeViewModel(boolean isLandscapeEnabled) {
     deviceOrientationMonitor = new DeviceOrientationMonitor(this);
     getLifecycle().addObserver(deviceOrientationMonitor);
 
     WebRtcCallViewModel.Factory factory = new WebRtcCallViewModel.Factory(deviceOrientationMonitor);
 
     viewModel = ViewModelProviders.of(this, factory).get(WebRtcCallViewModel.class);
+    viewModel.setIsLandscapeEnabled(isLandscapeEnabled);
     viewModel.setIsInPipMode(isInPipMode());
     viewModel.getMicrophoneEnabled().observe(this, callScreen::setMicEnabled);
     viewModel.getWebRtcControls().observe(this, callScreen::setWebRtcControls);
@@ -276,25 +312,13 @@ public class WebRtcCallActivity extends BaseActivity implements SafetyNumberChan
       }
     });
 
-    viewModel.getOrientation().observe(this, orientation -> {
+    viewModel.getOrientationAndLandscapeEnabled().observe(this, pair -> ApplicationDependencies.getSignalCallManager().orientationChanged(pair.second, pair.first.getDegrees()));
-      ApplicationDependencies.getSignalCallManager().orientationChanged(orientation.getDegrees());
+    viewModel.getControlsRotation().observe(this, callScreen::rotateControls);
-
-      switch (orientation) {
-        case LANDSCAPE_LEFT_EDGE:
-          callScreen.rotateControls(90);
-          break;
-        case LANDSCAPE_RIGHT_EDGE:
-          callScreen.rotateControls(-90);
-          break;
-        case PORTRAIT_BOTTOM_EDGE:
-          callScreen.rotateControls(0);
-      }
-    });
   }
 
   private void handleViewModelEvent(@NonNull WebRtcCallViewModel.Event event) {
     if (event instanceof WebRtcCallViewModel.Event.StartCall) {
-      startCall(((WebRtcCallViewModel.Event.StartCall)event).isVideoCall());
+      startCall(((WebRtcCallViewModel.Event.StartCall) event).isVideoCall());
       return;
     } else if (event instanceof WebRtcCallViewModel.Event.ShowGroupCallSafetyNumberChange) {
       SafetyNumberChangeDialog.showForGroupCall(getSupportFragmentManager(), ((WebRtcCallViewModel.Event.ShowGroupCallSafetyNumberChange) event).getIdentityRecords());
@@ -406,7 +430,7 @@ public class WebRtcCallActivity extends BaseActivity implements SafetyNumberChan
                  .request(Manifest.permission.RECORD_AUDIO, Manifest.permission.CAMERA)
                  .ifNecessary()
                  .withRationaleDialog(getString(R.string.WebRtcCallActivity_to_answer_the_call_from_s_give_signal_access_to_your_microphone, recipient.getDisplayName(this)),
-                     R.drawable.ic_mic_solid_24, R.drawable.ic_video_solid_24_tinted)
+                                      R.drawable.ic_mic_solid_24, R.drawable.ic_video_solid_24_tinted)
                  .withPermanentDenialDialog(getString(R.string.WebRtcCallActivity_signal_requires_microphone_and_camera_permissions_in_order_to_make_or_receive_calls))
                  .onAllGranted(() -> {
                    callScreen.setRecipient(recipient);
@@ -490,13 +514,13 @@ public class WebRtcCallActivity extends BaseActivity implements SafetyNumberChan
   private void handleNoSuchUser(final @NonNull WebRtcViewModel event) {
     if (isFinishing()) return; // XXX Stuart added this check above, not sure why, so I'm repeating in ignorance. - moxie
     new AlertDialog.Builder(this)
-                   .setTitle(R.string.RedPhone_number_not_registered)
+        .setTitle(R.string.RedPhone_number_not_registered)
-                   .setIcon(R.drawable.ic_warning)
+        .setIcon(R.drawable.ic_warning)
-                   .setMessage(R.string.RedPhone_the_number_you_dialed_does_not_support_secure_voice)
+        .setMessage(R.string.RedPhone_the_number_you_dialed_does_not_support_secure_voice)
-                   .setCancelable(true)
+        .setCancelable(true)
-                   .setPositiveButton(R.string.RedPhone_got_it, (d, w) -> handleTerminate(event.getRecipient(), HangupMessage.Type.NORMAL))
+        .setPositiveButton(R.string.RedPhone_got_it, (d, w) -> handleTerminate(event.getRecipient(), HangupMessage.Type.NORMAL))
-                   .setOnCancelListener(d -> handleTerminate(event.getRecipient(), HangupMessage.Type.NORMAL))
+        .setOnCancelListener(d -> handleTerminate(event.getRecipient(), HangupMessage.Type.NORMAL))
-                   .show();
+        .show();
   }
 
   private void handleUntrustedIdentity(@NonNull WebRtcViewModel event) {
@@ -588,20 +612,34 @@ public class WebRtcCallActivity extends BaseActivity implements SafetyNumberChan
     callScreen.setRecipient(event.getRecipient());
 
     switch (event.getState()) {
-      case CALL_PRE_JOIN:           handleCallPreJoin(event);                                                  break;
+      case CALL_PRE_JOIN:
-      case CALL_CONNECTED:          handleCallConnected(event);                                                break;
+        handleCallPreJoin(event); break;
-      case NETWORK_FAILURE:         handleServerFailure();                                                     break;
+      case CALL_CONNECTED:
-      case CALL_RINGING:            handleCallRinging();                                                       break;
+        handleCallConnected(event); break;
-      case CALL_DISCONNECTED:       handleTerminate(event.getRecipient(), HangupMessage.Type.NORMAL);          break;
+      case NETWORK_FAILURE:
-      case CALL_ACCEPTED_ELSEWHERE: handleTerminate(event.getRecipient(), HangupMessage.Type.ACCEPTED);        break;
+        handleServerFailure(); break;
-      case CALL_DECLINED_ELSEWHERE: handleTerminate(event.getRecipient(), HangupMessage.Type.DECLINED);        break;
+      case CALL_RINGING:
-      case CALL_ONGOING_ELSEWHERE:  handleTerminate(event.getRecipient(), HangupMessage.Type.BUSY);            break;
+        handleCallRinging(); break;
-      case CALL_NEEDS_PERMISSION:   handleTerminate(event.getRecipient(), HangupMessage.Type.NEED_PERMISSION); break;
+      case CALL_DISCONNECTED:
-      case NO_SUCH_USER:            handleNoSuchUser(event);                                                   break;
+        handleTerminate(event.getRecipient(), HangupMessage.Type.NORMAL); break;
-      case RECIPIENT_UNAVAILABLE:   handleRecipientUnavailable();                                              break;
+      case CALL_ACCEPTED_ELSEWHERE:
-      case CALL_OUTGOING:           handleOutgoingCall(event);                                                 break;
+        handleTerminate(event.getRecipient(), HangupMessage.Type.ACCEPTED); break;
-      case CALL_BUSY:               handleCallBusy();                                                          break;
+      case CALL_DECLINED_ELSEWHERE:
-      case UNTRUSTED_IDENTITY:      handleUntrustedIdentity(event);                                            break;
+        handleTerminate(event.getRecipient(), HangupMessage.Type.DECLINED); break;
+      case CALL_ONGOING_ELSEWHERE:
+        handleTerminate(event.getRecipient(), HangupMessage.Type.BUSY); break;
+      case CALL_NEEDS_PERMISSION:
+        handleTerminate(event.getRecipient(), HangupMessage.Type.NEED_PERMISSION); break;
+      case NO_SUCH_USER:
+        handleNoSuchUser(event); break;
+      case RECIPIENT_UNAVAILABLE:
+        handleRecipientUnavailable(); break;
+      case CALL_OUTGOING:
+        handleOutgoingCall(event); break;
+      case CALL_BUSY:
+        handleCallBusy(); break;
+      case UNTRUSTED_IDENTITY:
+        handleUntrustedIdentity(event); break;
     }
 
     boolean enableVideo = event.getLocalParticipant().getCameraState().getCameraCount() > 0 && enableVideoIfAvailable;
@@ -732,4 +770,31 @@ public class WebRtcCallActivity extends BaseActivity implements SafetyNumberChan
       viewModel.onLocalPictureInPictureClicked();
     }
   }
+
+  private class WindowLayoutInfoConsumer implements Consumer<WindowLayoutInfo> {
+
+    private final androidx.window.WindowManager windowManager;
+
+    private WindowLayoutInfoConsumer(androidx.window.WindowManager windowManager) {
+      this.windowManager = windowManager;
+    }
+
+    @Override
+    public void accept(WindowLayoutInfo windowLayoutInfo) {
+      Log.d(TAG, "On WindowLayoutInfo accepted: " + windowLayoutInfo.toString());
+
+      Optional<DisplayFeature> feature = windowLayoutInfo.getDisplayFeatures().stream().filter(f -> f instanceof FoldingFeature).findFirst();
+      if (feature.isPresent()) {
+        FoldingFeature foldingFeature = (FoldingFeature) feature.get();
+        Rect bounds = foldingFeature.getBounds();
+        if (foldingFeature.getState() == FoldingFeature.State.HALF_OPENED && bounds.top == bounds.bottom) {
+          Log.d(TAG, "OnWindowLayoutInfo accepted: ensure call view is in table-top display mode");
+          viewModel.setFoldableState(WebRtcControls.FoldableState.folded(bounds.top));
+        } else {
+          Log.d(TAG, "OnWindowLayoutInfo accepted: ensure call view is in flat display mode");
+          viewModel.setFoldableState(WebRtcControls.FoldableState.flat());
+        }
+      }
+    }
+  }
 }

app/src/main/java/org/thoughtcrime/securesms/components/webrtc/BroadcastVideoSink.java

@@ -20,6 +20,8 @@ import java.util.WeakHashMap;
  */
 public class BroadcastVideoSink implements VideoSink {
 
+  public static final int DEVICE_ROTATION_IGNORE = -1;
+
   private final EglBase                         eglBase;
   private final WeakHashMap<VideoSink, Boolean> sinks;
   private final WeakHashMap<Object, Point>      requestingSizes;
@@ -85,7 +87,10 @@ public class BroadcastVideoSink implements VideoSink {
 
   @Override
   public synchronized void onFrame(@NonNull VideoFrame videoFrame) {
-    if (videoFrame.getRotatedHeight() < videoFrame.getRotatedWidth() || forceRotate) {
+    boolean isDeviceRotationIgnored = deviceOrientationDegrees == DEVICE_ROTATION_IGNORE;
+    boolean isWideVideoFrame        = videoFrame.getRotatedHeight() < videoFrame.getRotatedWidth();
+
+    if (!isDeviceRotationIgnored && (isWideVideoFrame || forceRotate)) {
       int rotation = calculateRotation();
       if (rotation > 0) {
         rotation += rotateWithDevice ? videoFrame.getRotation() : 0;

app/src/main/java/org/thoughtcrime/securesms/components/webrtc/CallParticipantsLayout.java

@@ -34,6 +34,7 @@ public class CallParticipantsLayout extends FlexboxLayout {
   private CallParticipant       focusedParticipant = null;
   private boolean               shouldRenderInPip;
   private boolean               isPortrait;
+  private LayoutStrategy        layoutStrategy;
 
   public CallParticipantsLayout(@NonNull Context context) {
     super(context);
@@ -47,11 +48,18 @@ public class CallParticipantsLayout extends FlexboxLayout {
     super(context, attrs, defStyleAttr);
   }
 
-  void update(@NonNull List<CallParticipant> callParticipants, @NonNull CallParticipant focusedParticipant, boolean shouldRenderInPip, boolean isPortrait) {
+  void update(@NonNull List<CallParticipant> callParticipants,
+              @NonNull CallParticipant focusedParticipant,
+              boolean shouldRenderInPip,
+              boolean isPortrait,
+              @NonNull LayoutStrategy layoutStrategy)
+  {
     this.callParticipants   = callParticipants;
     this.focusedParticipant = focusedParticipant;
     this.shouldRenderInPip  = shouldRenderInPip;
     this.isPortrait         = isPortrait;
+    this.layoutStrategy     = layoutStrategy;
+    setFlexDirection(layoutStrategy.getFlexDirection());
     updateLayout();
   }
 
@@ -127,7 +135,7 @@ public class CallParticipantsLayout extends FlexboxLayout {
       callParticipantView.useLargeAvatar();
     }
 
-    setChildLayoutParams(view, index, getChildCount());
+    layoutStrategy.setChildLayoutParams(view, index, getChildCount());
   }
 
   private void addCallParticipantView() {
@@ -139,17 +147,9 @@ public class CallParticipantsLayout extends FlexboxLayout {
     addView(view);
   }
 
-  private void setChildLayoutParams(@NonNull View child, int childPosition, int childCount) {
+  public interface LayoutStrategy {
-    FlexboxLayout.LayoutParams params = (FlexboxLayout.LayoutParams) child.getLayoutParams();
+    int getFlexDirection();
-    if (childCount < 3) {
+
-      params.setFlexBasisPercent(1f);
+    void setChildLayoutParams(@NonNull View child, int childPosition, int childCount);
-    } else {
-      if ((childCount % 2) != 0 && childPosition == childCount - 1) {
-        params.setFlexBasisPercent(1f);
-      } else {
-        params.setFlexBasisPercent(0.5f);
-      }
-    }
-    child.setLayoutParams(params);
   }
 }

app/src/main/java/org/thoughtcrime/securesms/components/webrtc/CallParticipantsLayoutStrategies.kt

@@ -0,0 +1,53 @@
+package org.thoughtcrime.securesms.components.webrtc
+
+import android.view.View
+import com.google.android.flexbox.FlexDirection
+import com.google.android.flexbox.FlexboxLayout
+
+object CallParticipantsLayoutStrategies {
+
+  private object Portrait : CallParticipantsLayout.LayoutStrategy {
+    override fun getFlexDirection(): Int = FlexDirection.ROW
+
+    override fun setChildLayoutParams(child: View, childPosition: Int, childCount: Int) {
+      val params = child.layoutParams as FlexboxLayout.LayoutParams
+      if (childCount < 3) {
+        params.flexBasisPercent = 1f
+      } else {
+        if ((childCount % 2) != 0 && childPosition == childCount - 1) {
+          params.flexBasisPercent = 1f
+        } else {
+          params.flexBasisPercent = 0.5f
+        }
+      }
+      child.layoutParams = params
+    }
+  }
+
+  private object Landscape : CallParticipantsLayout.LayoutStrategy {
+    override fun getFlexDirection() = FlexDirection.COLUMN
+
+    override fun setChildLayoutParams(child: View, childPosition: Int, childCount: Int) {
+      val params = child.layoutParams as FlexboxLayout.LayoutParams
+      if (childCount < 4) {
+        params.flexBasisPercent = 1f
+      } else {
+        if ((childCount % 2) != 0 && childPosition == childCount - 1) {
+          params.flexBasisPercent = 1f
+        } else {
+          params.flexBasisPercent = 0.5f
+        }
+      }
+      child.layoutParams = params
+    }
+  }
+
+  @JvmStatic
+  fun getStrategy(isPortrait: Boolean): CallParticipantsLayout.LayoutStrategy {
+    return if (isPortrait) {
+      Portrait
+    } else {
+      Landscape
+    }
+  }
+}

app/src/main/java/org/thoughtcrime/securesms/components/webrtc/CallParticipantsState.java

@@ -36,7 +36,8 @@ public final class CallParticipantsState {
                                                                                        false,
                                                                                        false,
                                                                                        false,
-                                                                                       OptionalLong.empty());
+                                                                                       OptionalLong.empty(),
+                                                                                       WebRtcControls.FoldableState.flat());
 
   private final WebRtcViewModel.State          callState;
   private final WebRtcViewModel.GroupCallState groupCallState;
@@ -48,6 +49,7 @@ public final class CallParticipantsState {
   private final boolean                        showVideoForOutgoing;
   private final boolean                        isViewingFocusedParticipant;
   private final OptionalLong                   remoteDevicesCount;
+  private final WebRtcControls.FoldableState   foldableState;
 
   public CallParticipantsState(@NonNull WebRtcViewModel.State callState,
                                @NonNull WebRtcViewModel.GroupCallState groupCallState,
@@ -58,7 +60,8 @@ public final class CallParticipantsState {
                                boolean isInPipMode,
                                boolean showVideoForOutgoing,
                                boolean isViewingFocusedParticipant,
-                               OptionalLong remoteDevicesCount)
+                               OptionalLong remoteDevicesCount,
+                               @NonNull WebRtcControls.FoldableState foldableState)
   {
     this.callState                   = callState;
     this.groupCallState              = groupCallState;
@@ -70,6 +73,7 @@ public final class CallParticipantsState {
     this.showVideoForOutgoing        = showVideoForOutgoing;
     this.isViewingFocusedParticipant = isViewingFocusedParticipant;
     this.remoteDevicesCount          = remoteDevicesCount;
+    this.foldableState               = foldableState;
   }
 
   public @NonNull WebRtcViewModel.State getCallState() {
@@ -94,7 +98,10 @@ public final class CallParticipantsState {
       listParticipants.addAll(remoteParticipants.getListParticipants());
     }
 
-    listParticipants.add(CallParticipant.EMPTY);
+    if (foldableState.isFlat()) {
+      listParticipants.add(CallParticipant.EMPTY);
+    }
+
     Collections.reverse(listParticipants);
 
     return listParticipants;
@@ -155,6 +162,10 @@ public final class CallParticipantsState {
     return localRenderState;
   }
 
+  public boolean isFolded() {
+    return foldableState.isFolded();
+  }
+
   public boolean isLargeVideoGroup() {
     return getAllRemoteParticipants().size() > SMALL_GROUP_MAX;
   }
@@ -215,7 +226,8 @@ public final class CallParticipantsState {
                                      oldState.isInPipMode,
                                      newShowVideoForOutgoing,
                                      oldState.isViewingFocusedParticipant,
-                                     webRtcViewModel.getRemoteDevicesCount());
+                                     webRtcViewModel.getRemoteDevicesCount(),
+                                     oldState.foldableState);
   }
 
   public static @NonNull CallParticipantsState update(@NonNull CallParticipantsState oldState, boolean isInPip) {
@@ -237,7 +249,8 @@ public final class CallParticipantsState {
                                      isInPip,
                                      oldState.showVideoForOutgoing,
                                      oldState.isViewingFocusedParticipant,
-                                     oldState.remoteDevicesCount);
+                                     oldState.remoteDevicesCount,
+                                     oldState.foldableState);
   }
 
   public static @NonNull CallParticipantsState setExpanded(@NonNull CallParticipantsState oldState, boolean expanded) {
@@ -259,7 +272,8 @@ public final class CallParticipantsState {
                                      oldState.isInPipMode,
                                      oldState.showVideoForOutgoing,
                                      oldState.isViewingFocusedParticipant,
-                                     oldState.remoteDevicesCount);
+                                     oldState.remoteDevicesCount,
+                                     oldState.foldableState);
   }
 
   public static @NonNull CallParticipantsState update(@NonNull CallParticipantsState oldState, @NonNull SelectedPage selectedPage) {
@@ -281,7 +295,31 @@ public final class CallParticipantsState {
                                      oldState.isInPipMode,
                                      oldState.showVideoForOutgoing,
                                      selectedPage == SelectedPage.FOCUSED,
-                                     oldState.remoteDevicesCount);
+                                     oldState.remoteDevicesCount,
+                                     oldState.foldableState);
+  }
+
+  public static @NonNull CallParticipantsState update(@NonNull CallParticipantsState oldState, @NonNull WebRtcControls.FoldableState foldableState) {
+    WebRtcLocalRenderState localRenderState = determineLocalRenderMode(oldState.localParticipant,
+                                                                       oldState.isInPipMode,
+                                                                       oldState.showVideoForOutgoing,
+                                                                       oldState.getGroupCallState().isNotIdle(),
+                                                                       oldState.callState,
+                                                                       oldState.getAllRemoteParticipants().size(),
+                                                                       oldState.isViewingFocusedParticipant,
+                                                                       oldState.getLocalRenderState() == WebRtcLocalRenderState.EXPANDED);
+
+    return new CallParticipantsState(oldState.callState,
+                                     oldState.groupCallState,
+                                     oldState.remoteParticipants,
+                                     oldState.localParticipant,
+                                     oldState.focusedParticipant,
+                                     localRenderState,
+                                     oldState.isInPipMode,
+                                     oldState.showVideoForOutgoing,
+                                     oldState.isViewingFocusedParticipant,
+                                     oldState.remoteDevicesCount,
+                                     foldableState);
   }
 
   private static @NonNull WebRtcLocalRenderState determineLocalRenderMode(@NonNull CallParticipant localParticipant,

app/src/main/java/org/thoughtcrime/securesms/components/webrtc/PictureInPictureGestureHelper.java

@@ -116,14 +116,16 @@ public class PictureInPictureGestureHelper extends GestureDetector.SimpleOnGestu
   }
 
   public void clearVerticalBoundaries() {
-    setVerticalBoundaries(parent.getTop(), parent.getMeasuredHeight() + parent.getTop());
+    setTopVerticalBoundary(parent.getTop());
+    setBottomVerticalBoundary(parent.getMeasuredHeight() + parent.getTop());
   }
 
-  public void setVerticalBoundaries(int topBoundary, int bottomBoundary) {
+  public void setTopVerticalBoundary(int topBoundary) {
-    extraPaddingTop    = topBoundary - parent.getTop();
+    extraPaddingTop = topBoundary - parent.getTop();
-    extraPaddingBottom = parent.getMeasuredHeight() + parent.getTop() - bottomBoundary;
+  }
 
-    adjustPip();
+  public void setBottomVerticalBoundary(int bottomBoundary) {
+    extraPaddingBottom = parent.getMeasuredHeight() + parent.getTop() - bottomBoundary;
   }
 
   private boolean onGestureFinished(MotionEvent e) {

app/src/main/java/org/thoughtcrime/securesms/components/webrtc/WebRtcCallParticipantsPage.java

@@ -64,6 +64,10 @@ class WebRtcCallParticipantsPage {
     return isPortrait;
   }
 
+  public @NonNull CallParticipantsLayout.LayoutStrategy getLayoutStrategy() {
+    return CallParticipantsLayoutStrategies.getStrategy(isPortrait);
+  }
+
   @Override
   public boolean equals(Object o) {
     if (this == o) return true;

app/src/main/java/org/thoughtcrime/securesms/components/webrtc/WebRtcCallParticipantsPagerAdapter.java

@@ -86,7 +86,7 @@ class WebRtcCallParticipantsPagerAdapter extends ListAdapter<WebRtcCallParticipa
 
     @Override
     void bind(WebRtcCallParticipantsPage page) {
-      callParticipantsLayout.update(page.getCallParticipants(), page.getFocusedParticipant(), page.isRenderInPip(), page.isPortrait());
+      callParticipantsLayout.update(page.getCallParticipants(), page.getFocusedParticipant(), page.isRenderInPip(), page.isPortrait(), page.getLayoutStrategy());
     }
   }
 

app/src/main/java/org/thoughtcrime/securesms/components/webrtc/WebRtcCallView.java

@@ -36,7 +36,6 @@ import com.google.android.material.button.MaterialButton;
 import org.thoughtcrime.securesms.R;
 import org.thoughtcrime.securesms.animation.ResizeAnimation;
 import org.thoughtcrime.securesms.components.AccessibleToggleButton;
-import org.thoughtcrime.securesms.components.sensors.Orientation;
 import org.thoughtcrime.securesms.contacts.avatars.ProfileContactPhoto;
 import org.thoughtcrime.securesms.events.CallParticipant;
 import org.thoughtcrime.securesms.events.WebRtcViewModel;
@@ -46,6 +45,7 @@ import org.thoughtcrime.securesms.recipients.Recipient;
 import org.thoughtcrime.securesms.recipients.RecipientId;
 import org.thoughtcrime.securesms.ringrtc.CameraState;
 import org.thoughtcrime.securesms.util.BlurTransformation;
+import org.thoughtcrime.securesms.util.ServiceUtil;
 import org.thoughtcrime.securesms.util.SetUtil;
 import org.thoughtcrime.securesms.util.ViewUtil;
 import org.thoughtcrime.securesms.util.views.Stub;
@@ -57,9 +57,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
-import static org.thoughtcrime.securesms.components.sensors.Orientation.PORTRAIT_BOTTOM_EDGE;
+public class WebRtcCallView extends ConstraintLayout {
-
-public class WebRtcCallView extends FrameLayout {
 
   private static final long TRANSITION_DURATION_MILLIS          = 250;
   private static final int  SMALL_ONGOING_CALL_BUTTON_MARGIN_DP = 8;
@@ -102,12 +100,15 @@ public class WebRtcCallView extends FrameLayout {
   private View                          errorButton;
   private int                           pagerBottomMarginDp;
   private boolean                       controlsVisible = true;
+  private Guideline                     topFoldGuideline;
+  private Guideline                     callScreenTopFoldGuideline;
+  private View                          foldParticipantCountWrapper;
+  private TextView                      foldParticipantCount;
 
   private WebRtcCallParticipantsPagerAdapter    pagerAdapter;
   private WebRtcCallParticipantsRecyclerAdapter recyclerAdapter;
   private PictureInPictureExpansionHelper       pictureInPictureExpansionHelper;
 
-
   private final Set<View> incomingCallViews    = new HashSet<>();
   private final Set<View> topViews             = new HashSet<>();
   private final Set<View> visibleViewSet       = new HashSet<>();
@@ -161,6 +162,10 @@ public class WebRtcCallView extends FrameLayout {
     errorButton                   = findViewById(R.id.call_screen_error_cancel);
     groupCallSpeakerHint          = new Stub<>(findViewById(R.id.call_screen_group_call_speaker_hint));
     groupCallFullStub             = new Stub<>(findViewById(R.id.group_call_call_full_view));
+    topFoldGuideline              = findViewById(R.id.fold_top_guideline);
+    callScreenTopFoldGuideline    = findViewById(R.id.fold_top_call_screen_guideline);
+    foldParticipantCountWrapper   = findViewById(R.id.fold_show_participants_menu_counter_wrapper);
+    foldParticipantCount          = findViewById(R.id.fold_show_participants_menu_counter);
 
     View      topGradient            = findViewById(R.id.call_screen_header_gradient);
     View      decline                = findViewById(R.id.call_screen_decline_call);
@@ -279,10 +284,18 @@ public class WebRtcCallView extends FrameLayout {
   @Override
   public void onWindowSystemUiVisibilityChanged(int visible) {
     if ((visible & SYSTEM_UI_FLAG_HIDE_NAVIGATION) == 0) {
-      pictureInPictureGestureHelper.setVerticalBoundaries(toolbar.getBottom(), videoToggle.getTop());
+      if (controls.adjustForFold()) {
+        pictureInPictureGestureHelper.clearVerticalBoundaries();
+        pictureInPictureGestureHelper.setTopVerticalBoundary(toolbar.getBottom());
+      } else {
+        pictureInPictureGestureHelper.setTopVerticalBoundary(toolbar.getBottom());
+        pictureInPictureGestureHelper.setBottomVerticalBoundary(videoToggle.getTop());
+      }
     } else {
       pictureInPictureGestureHelper.clearVerticalBoundaries();
     }
+
+    pictureInPictureGestureHelper.adjustPip();
   }
 
   @Override
@@ -323,16 +336,22 @@ public class WebRtcCallView extends FrameLayout {
     }
 
     if (state.getGroupCallState().isNotIdle() && participantCount != null) {
-      participantCount.setText(state.getParticipantCount()
+      String  text    = state.getParticipantCount()
-                                    .mapToObj(String::valueOf).orElse("\u2014"));
+                             .mapToObj(String::valueOf).orElse("\u2014");
-      participantCount.setEnabled(state.getParticipantCount().isPresent());
+      boolean enabled = state.getParticipantCount().isPresent();
+
+      participantCount.setText(text);
+      participantCount.setEnabled(enabled);
+
+      foldParticipantCount.setText(text);
+      foldParticipantCount.setEnabled(enabled);
     }
 
     pagerAdapter.submitList(pages);
     recyclerAdapter.submitList(state.getListParticipants());
     updateLocalCallParticipant(state.getLocalRenderState(), state.getLocalParticipant(), state.getFocusedParticipant());
 
-    if (state.isLargeVideoGroup() && !state.isInPipMode()) {
+    if (state.isLargeVideoGroup() && !state.isInPipMode() && !state.isFolded()) {
       layoutParticipantsForLargeCount();
     } else {
       layoutParticipantsForSmallCount();
@@ -423,7 +442,9 @@ public class WebRtcCallView extends FrameLayout {
         toolbar.inflateMenu(R.menu.group_call);
 
         View showParticipants = toolbar.getMenu().findItem(R.id.menu_group_call_participants_list).getActionView();
+        showParticipants.setAlpha(0);
         showParticipants.setOnClickListener(unused -> showParticipantsList());
+        foldParticipantCountWrapper.setOnClickListener(unused -> showParticipantsList());
 
         participantCount = showParticipants.findViewById(R.id.show_participants_menu_counter);
       }
@@ -480,6 +501,20 @@ public class WebRtcCallView extends FrameLayout {
 
     visibleViewSet.clear();
 
+    if (webRtcControls.adjustForFold()) {
+      topFoldGuideline.setGuidelineEnd(webRtcControls.getFold());
+      callScreenTopFoldGuideline.setGuidelineEnd(webRtcControls.getFold());
+
+      if (webRtcControls.displayGroupMembersButton()) {
+        visibleViewSet.add(foldParticipantCountWrapper);
+      }
+    } else {
+      topFoldGuideline.setGuidelineEnd(0);
+      callScreenTopFoldGuideline.setGuidelineEnd(0);
+    }
+
+    setShowParticipantsState(webRtcControls.adjustForFold());
+
     if (webRtcControls.displayStartCallControls()) {
       visibleViewSet.add(footerGradient);
       visibleViewSet.add(startCallControls);
@@ -577,10 +612,15 @@ public class WebRtcCallView extends FrameLayout {
 
     controls = webRtcControls;
 
+    if (!controls.isFadeOutEnabled()) {
+      controlsVisible = true;
+    }
+
     if (!visibleViewSet.equals(lastVisibleSet) || !controls.isFadeOutEnabled()) {
       fadeInNewUiState(lastVisibleSet, webRtcControls.displaySmallOngoingCallButtons());
-      post(() -> pictureInPictureGestureHelper.setVerticalBoundaries(toolbar.getBottom(), videoToggle.getTop()));
     }
+
+    onWindowSystemUiVisibilityChanged(getWindowSystemUiVisibility());
   }
 
   public @NonNull View getVideoTooltipTarget() {
@@ -597,6 +637,18 @@ public class WebRtcCallView extends FrameLayout {
     }
   }
 
+  private void setShowParticipantsState(boolean isFolded) {
+    MenuItem item = toolbar.getMenu().findItem(R.id.menu_group_call_participants_list);
+
+    if (item != null) {
+      View showParticipants = item.getActionView();
+      showParticipants.animate().alpha(isFolded ? 0f : 1f);
+      showParticipants.setClickable(!isFolded);
+      foldParticipantCountWrapper.animate().alpha(isFolded ? 1f : 0f);
+      foldParticipantCount.setClickable(isFolded);
+    }
+  }
+
   private void expandPip(@NonNull CallParticipant localCallParticipant, @NonNull CallParticipant focusedParticipant) {
     pictureInPictureExpansionHelper.expand(smallLocalRenderFrame, new PictureInPictureExpansionHelper.Callback() {
       @Override
@@ -760,6 +812,8 @@ public class WebRtcCallView extends FrameLayout {
       constraintSet.setVisibility(view.getId(), visibility);
     }
 
+    adjustParticipantsRecycler(constraintSet);
+
     constraintSet.applyTo(parent);
 
     layoutParticipants();
@@ -789,9 +843,21 @@ public class WebRtcCallView extends FrameLayout {
       }
     }
 
+    adjustParticipantsRecycler(constraintSet);
+
     constraintSet.applyTo(parent);
   }
 
+  private void adjustParticipantsRecycler(@NonNull ConstraintSet constraintSet) {
+    if (controlsVisible) {
+      constraintSet.connect(R.id.call_screen_participants_recycler, ConstraintSet.BOTTOM, R.id.call_screen_video_toggle, ConstraintSet.TOP);
+    } else {
+      constraintSet.connect(R.id.call_screen_participants_recycler, ConstraintSet.BOTTOM, ConstraintSet.PARENT_ID, ConstraintSet.BOTTOM);
+    }
+
+    constraintSet.setHorizontalBias(R.id.call_screen_participants_recycler, controls.adjustForFold() ? 0.5f : 1f);
+  }
+
   private void scheduleFadeOut() {
     cancelFadeOut();
 

app/src/main/java/org/thoughtcrime/securesms/components/webrtc/WebRtcCallViewModel.java

@@ -2,6 +2,7 @@ package org.thoughtcrime.securesms.components.webrtc;
 
 import android.os.Handler;
 import android.os.Looper;
+import android.util.Pair;
 
 import androidx.annotation.MainThread;
 import androidx.annotation.NonNull;
@@ -14,6 +15,7 @@ import androidx.lifecycle.ViewModelProvider;
 
 import com.annimon.stream.Stream;
 
+import org.signal.core.util.ThreadUtil;
 import org.thoughtcrime.securesms.components.sensors.DeviceOrientationMonitor;
 import org.thoughtcrime.securesms.components.sensors.Orientation;
 import org.thoughtcrime.securesms.database.IdentityDatabase;
@@ -41,7 +43,9 @@ public class WebRtcCallViewModel extends ViewModel {
   private final MutableLiveData<Boolean>                       microphoneEnabled         = new MutableLiveData<>(true);
   private final MutableLiveData<Boolean>                       isInPipMode               = new MutableLiveData<>(false);
   private final MutableLiveData<WebRtcControls>                webRtcControls            = new MutableLiveData<>(WebRtcControls.NONE);
-  private final LiveData<WebRtcControls>                       realWebRtcControls        = LiveDataUtil.combineLatest(isInPipMode, webRtcControls, this::getRealWebRtcControls);
+  private final MutableLiveData<WebRtcControls.FoldableState>  foldableState             = new MutableLiveData<>(WebRtcControls.FoldableState.flat());
+  private final LiveData<WebRtcControls>                       controlsWithFoldableState = LiveDataUtil.combineLatest(foldableState, webRtcControls, this::updateControlsFoldableState);
+  private final LiveData<WebRtcControls>                       realWebRtcControls        = LiveDataUtil.combineLatest(isInPipMode, controlsWithFoldableState, this::getRealWebRtcControls);
   private final SingleLiveEvent<Event>                         events                    = new SingleLiveEvent<Event>();
   private final MutableLiveData<Long>                          elapsed                   = new MutableLiveData<>(-1L);
   private final MutableLiveData<LiveRecipient>                 liveRecipient             = new MutableLiveData<>(Recipient.UNKNOWN.live());
@@ -53,6 +57,8 @@ public class WebRtcCallViewModel extends ViewModel {
   private final LiveData<List<GroupMemberEntry.FullMember>>    groupMembers              = LiveDataUtil.skip(Transformations.switchMap(groupRecipient, r -> Transformations.distinctUntilChanged(new LiveGroup(r.requireGroupId()).getFullMembers())), 1);
   private final LiveData<Boolean>                              shouldShowSpeakerHint     = Transformations.map(participantsState, this::shouldShowSpeakerHint);
   private final LiveData<Orientation>                          orientation;
+  private final MutableLiveData<Boolean>                       isLandscapeEnabled        = new MutableLiveData<>();
+  private final LiveData<Integer>                              controlsRotation;
 
   private boolean               canDisplayTooltipIfNeeded = true;
   private boolean               hasEnabledLocalVideo      = false;
@@ -69,13 +75,24 @@ public class WebRtcCallViewModel extends ViewModel {
   private final WebRtcCallRepository repository = new WebRtcCallRepository(ApplicationDependencies.getApplication());
 
   private WebRtcCallViewModel(@NonNull DeviceOrientationMonitor deviceOrientationMonitor) {
-    orientation = deviceOrientationMonitor.getOrientation();
+    orientation      = deviceOrientationMonitor.getOrientation();
+    controlsRotation = LiveDataUtil.combineLatest(Transformations.distinctUntilChanged(isLandscapeEnabled),
+                                                  Transformations.distinctUntilChanged(orientation),
+                                                  this::resolveRotation);
+  }
+
+  public LiveData<Integer> getControlsRotation() {
+    return controlsRotation;
   }
 
   public LiveData<Orientation> getOrientation() {
     return Transformations.distinctUntilChanged(orientation);
   }
 
+  public LiveData<Pair<Orientation, Boolean>> getOrientationAndLandscapeEnabled() {
+    return LiveDataUtil.combineLatest(orientation, isLandscapeEnabled, Pair::new);
+  }
+
   public LiveData<Boolean> getMicrophoneEnabled() {
     return Transformations.distinctUntilChanged(microphoneEnabled);
   }
@@ -92,6 +109,12 @@ public class WebRtcCallViewModel extends ViewModel {
     liveRecipient.setValue(recipient.live());
   }
 
+  public void setFoldableState(@NonNull WebRtcControls.FoldableState foldableState) {
+    this.foldableState.postValue(foldableState);
+
+    ThreadUtil.runOnMain(() -> participantsState.setValue(CallParticipantsState.update(participantsState.getValue(), foldableState)));
+  }
+
   public LiveData<Event> getEvents() {
     return events;
   }
@@ -140,6 +163,10 @@ public class WebRtcCallViewModel extends ViewModel {
     participantsState.setValue(CallParticipantsState.update(participantsState.getValue(), isInPipMode));
   }
 
+  public void setIsLandscapeEnabled(boolean isLandscapeEnabled) {
+    this.isLandscapeEnabled.postValue(isLandscapeEnabled);
+  }
+
   @MainThread
   public void setIsViewingFocusedParticipant(@NonNull CallParticipantsState.SelectedPage page) {
     if (page == CallParticipantsState.SelectedPage.FOCUSED) {
@@ -239,6 +266,23 @@ public class WebRtcCallViewModel extends ViewModel {
     }
   }
 
+  private int resolveRotation(boolean isLandscapeEnabled, @NonNull Orientation orientation) {
+    if (isLandscapeEnabled) {
+      return 0;
+    }
+
+    switch (orientation) {
+      case LANDSCAPE_LEFT_EDGE:
+        return 90;
+      case LANDSCAPE_RIGHT_EDGE:
+        return -90;
+      case PORTRAIT_BOTTOM_EDGE:
+        return 0;
+      default:
+        throw new AssertionError();
+    }
+  }
+
   private boolean containsPlaceholders(@NonNull List<CallParticipant> callParticipants) {
     return Stream.of(callParticipants).anyMatch(p -> p.getCallParticipantId().getDemuxId() == CallParticipantId.DEFAULT_ID);
   }
@@ -314,7 +358,12 @@ public class WebRtcCallViewModel extends ViewModel {
                                                callState,
                                                groupCallState,
                                                audioOutput,
-                                               participantLimit));
+                                               participantLimit,
+                                               WebRtcControls.FoldableState.flat()));
+  }
+
+  private @NonNull WebRtcControls updateControlsFoldableState(@NonNull WebRtcControls.FoldableState foldableState, @NonNull WebRtcControls controls) {
+    return controls.withFoldableState(foldableState);
   }
 
   private @NonNull WebRtcControls getRealWebRtcControls(boolean isInPipMode, @NonNull WebRtcControls controls) {

app/src/main/java/org/thoughtcrime/securesms/components/webrtc/WebRtcControls.java

@@ -4,6 +4,7 @@ import android.content.Context;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.annotation.Px;
 import androidx.annotation.StringRes;
 
 import org.thoughtcrime.securesms.R;
@@ -11,7 +12,7 @@ import org.thoughtcrime.securesms.R;
 public final class WebRtcControls {
 
   public static final WebRtcControls NONE = new WebRtcControls();
-  public static final WebRtcControls PIP  = new WebRtcControls(false, false, false, false, true, false, CallState.NONE, GroupCallState.NONE, WebRtcAudioOutput.HANDSET, null);
+  public static final WebRtcControls PIP  = new WebRtcControls(false, false, false, false, true, false, CallState.NONE, GroupCallState.NONE, WebRtcAudioOutput.HANDSET, null, FoldableState.flat());
 
   private final boolean           isRemoteVideoEnabled;
   private final boolean           isLocalVideoEnabled;
@@ -23,9 +24,10 @@ public final class WebRtcControls {
   private final GroupCallState    groupCallState;
   private final WebRtcAudioOutput audioOutput;
   private final Long              participantLimit;
+  private final FoldableState     foldableState;
 
   private WebRtcControls() {
-    this(false, false, false, false, false, false, CallState.NONE, GroupCallState.NONE, WebRtcAudioOutput.HANDSET, null);
+    this(false, false, false, false, false, false, CallState.NONE, GroupCallState.NONE, WebRtcAudioOutput.HANDSET, null, FoldableState.flat());
   }
 
   WebRtcControls(boolean isLocalVideoEnabled,
@@ -37,7 +39,8 @@ public final class WebRtcControls {
                  @NonNull CallState callState,
                  @NonNull GroupCallState groupCallState,
                  @NonNull WebRtcAudioOutput audioOutput,
-                 @Nullable Long participantLimit)
+                 @Nullable Long participantLimit,
+                 @NonNull FoldableState foldableState)
   {
     this.isLocalVideoEnabled          = isLocalVideoEnabled;
     this.isRemoteVideoEnabled         = isRemoteVideoEnabled;
@@ -49,6 +52,21 @@ public final class WebRtcControls {
     this.groupCallState               = groupCallState;
     this.audioOutput                  = audioOutput;
     this.participantLimit             = participantLimit;
+    this.foldableState                = foldableState;
+  }
+
+  public @NonNull WebRtcControls withFoldableState(FoldableState foldableState) {
+    return new WebRtcControls(isLocalVideoEnabled,
+                              isRemoteVideoEnabled,
+                              isMoreThanOneCameraAvailable,
+                              isBluetoothAvailable,
+                              isInPipMode,
+                              hasAtLeastOneRemote,
+                              callState,
+                              groupCallState,
+                              audioOutput,
+                              participantLimit,
+                              foldableState);
   }
 
   boolean displayErrorControls() {
@@ -59,6 +77,14 @@ public final class WebRtcControls {
     return isPreJoin();
   }
 
+  boolean adjustForFold() {
+    return foldableState.isFolded();
+  }
+
+  @Px int getFold() {
+    return foldableState.getFoldPoint();
+  }
+
   @StringRes int getStartCallButtonText() {
     if (isGroupCall()) {
       if (groupCallState == GroupCallState.FULL) {
@@ -130,7 +156,7 @@ public final class WebRtcControls {
   }
 
   boolean isFadeOutEnabled() {
-    return isAtLeastOutgoing() && isRemoteVideoEnabled;
+    return isAtLeastOutgoing() && isRemoteVideoEnabled && foldableState.isFlat();
   }
 
   boolean displaySmallOngoingCallButtons() {
@@ -199,4 +225,35 @@ public final class WebRtcControls {
       return compareTo(other) >= 0;
     }
   }
+
+  public static final class FoldableState {
+
+    private static final int NOT_SET = -1;
+
+    private final int foldPoint;
+
+    public FoldableState(int foldPoint) {
+      this.foldPoint = foldPoint;
+    }
+
+    public boolean isFolded() {
+      return foldPoint != NOT_SET;
+    }
+
+    public boolean isFlat() {
+      return foldPoint == NOT_SET;
+    }
+
+    public int getFoldPoint() {
+      return foldPoint;
+    }
+
+    public static @NonNull FoldableState folded(int foldPoint) {
+      return new FoldableState(foldPoint);
+    }
+
+    public static @NonNull FoldableState flat() {
+      return new FoldableState(NOT_SET);
+    }
+  }
 }

app/src/main/java/org/thoughtcrime/securesms/messagerequests/CalleeMustAcceptMessageRequestActivity.java

@@ -1,7 +1,9 @@
 package org.thoughtcrime.securesms.messagerequests;
 
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.Intent;
+import android.content.pm.ActivityInfo;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Looper;
@@ -44,11 +46,17 @@ public class CalleeMustAcceptMessageRequestActivity extends BaseActivity {
     return intent;
   }
 
+  @SuppressLint("SourceLockedOrientationActivity")
   @Override
   public void onCreate(@Nullable Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.callee_must_accept_message_request_dialog_fragment);
 
+    boolean callingFixedToPortrait = getResources().getConfiguration().densityDpi < 480;
+    if (callingFixedToPortrait) {
+      setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
+    }
+
     description = findViewById(R.id.description);
     avatar      = findViewById(R.id.avatar);
     okay        = findViewById(R.id.okay);

app/src/main/java/org/thoughtcrime/securesms/service/webrtc/SignalCallManager.java

@@ -168,8 +168,8 @@ public final class SignalCallManager implements CallManager.Observer, GroupCall.
     process((s, p) -> p.handleUpdateRenderedResolutions(s));
   }
 
-  public void orientationChanged(int degrees) {
+  public void orientationChanged(boolean isLandscapeEnabled, int degrees) {
-    process((s, p) -> p.handleOrientationChanged(s, degrees));
+    process((s, p) -> p.handleOrientationChanged(s, isLandscapeEnabled, degrees));
   }
 
   public void setAudioSpeaker(boolean isSpeaker) {
@@ -649,7 +649,7 @@ public final class SignalCallManager implements CallManager.Observer, GroupCall.
 
   @Override
   public void onFullyInitialized() {
-    process((s, p) -> p.handleOrientationChanged(s, s.getLocalDeviceState().getOrientation().getDegrees()));
+    process((s, p) -> p.handleOrientationChanged(s, false, s.getLocalDeviceState().getOrientation().getDegrees()));
   }
 
   @Override

app/src/main/java/org/thoughtcrime/securesms/service/webrtc/WebRtcActionProcessor.java

@@ -11,6 +11,7 @@ import org.signal.ringrtc.CallException;
 import org.signal.ringrtc.CallId;
 import org.signal.ringrtc.CallManager;
 import org.signal.ringrtc.GroupCall;
+import org.thoughtcrime.securesms.R;
 import org.thoughtcrime.securesms.components.sensors.Orientation;
 import org.thoughtcrime.securesms.components.webrtc.BroadcastVideoSink;
 import org.thoughtcrime.securesms.crypto.IdentityKeyUtil;
@@ -454,24 +455,27 @@ public abstract class WebRtcActionProcessor {
     return currentState;
   }
 
-  protected @NonNull WebRtcServiceState handleOrientationChanged(@NonNull WebRtcServiceState currentState, int orientationDegrees) {
+  protected @NonNull WebRtcServiceState handleOrientationChanged(@NonNull WebRtcServiceState currentState, boolean isLandscapeEnabled, int orientationDegrees) {
     Camera camera = currentState.getVideoState().getCamera();
     if (camera != null) {
       camera.setOrientation(orientationDegrees);
     }
 
+    int     sinkRotationDegrees      = isLandscapeEnabled ? BroadcastVideoSink.DEVICE_ROTATION_IGNORE : orientationDegrees;
+    int     stateRotationDegrees     = isLandscapeEnabled ? 0 : orientationDegrees;
+
     BroadcastVideoSink sink = currentState.getVideoState().getLocalSink();
     if (sink != null) {
-      sink.setDeviceOrientationDegrees(orientationDegrees);
+      sink.setDeviceOrientationDegrees(sinkRotationDegrees);
     }
 
     for (CallParticipant callParticipant : currentState.getCallInfoState().getRemoteCallParticipants()) {
-      callParticipant.getVideoSink().setDeviceOrientationDegrees(orientationDegrees);
+      callParticipant.getVideoSink().setDeviceOrientationDegrees(sinkRotationDegrees);
     }
 
     return currentState.builder()
                        .changeLocalDeviceState()
-                       .setOrientation(Orientation.fromDegrees(orientationDegrees))
+                       .setOrientation(Orientation.fromDegrees(stateRotationDegrees))
                        .build();
   }
 

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

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android"
+    android:shape="rectangle">
+
+    <gradient android:type="linear"
+        android:angle="90"
+        android:startColor="@color/transparent_black_60" />
+
+</shape>

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

@@ -4,10 +4,21 @@
     xmlns:tools="http://schemas.android.com/tools"
     tools:parentTag="org.thoughtcrime.securesms.components.webrtc.WebRtcCallView">
 
+    <androidx.constraintlayout.widget.Guideline
+        android:id="@+id/fold_top_guideline"
+        android:layout_width="0dp"
+        android:layout_height="0dp"
+        android:orientation="horizontal"
+        app:layout_constraintGuide_end="0dp" />
+
     <androidx.constraintlayout.widget.ConstraintLayout
         android:id="@+id/call_screen_participants_parent"
-        android:layout_width="match_parent"
+        android:layout_width="0dp"
-        android:layout_height="match_parent">
+        android:layout_height="0dp"
+        app:layout_constraintBottom_toTopOf="@id/fold_top_guideline"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent">
 
         <androidx.viewpager2.widget.ViewPager2
             android:id="@+id/call_screen_participants_pager"
@@ -21,22 +32,64 @@
 
     </androidx.constraintlayout.widget.ConstraintLayout>
 
-    <include
+    <FrameLayout
-        layout="@layout/webrtc_call_view_large_local_render"
+        android:id="@+id/call_screen_large_local_renderer_frame"
-        android:layout_width="match_parent"
+        android:layout_width="0dp"
-        android:layout_height="match_parent" />
+        android:layout_height="0dp"
+        android:background="@color/black"
+        app:layout_constraintBottom_toTopOf="@id/fold_top_guideline"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent">
+
+        <org.thoughtcrime.securesms.components.webrtc.TextureViewRenderer
+            android:id="@+id/call_screen_large_local_renderer"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent" />
+
+        <androidx.appcompat.widget.AppCompatImageView
+            android:id="@+id/call_screen_large_local_video_off_avatar"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:visibility="gone" />
+
+        <androidx.appcompat.widget.AppCompatTextView
+            android:id="@+id/call_screen_large_local_video_off"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center"
+            android:text="@string/WebRtcCallView__your_video_is_off"
+            android:textAppearance="@style/TextAppearance.Signal.Body2"
+            android:textColor="@color/white"
+            android:visibility="gone"
+            app:drawableTopCompat="@drawable/ic_video_off_solid_white_28"
+            tools:visibility="visible" />
+
+    </FrameLayout>
 
     <ViewStub
         android:id="@+id/group_call_call_full_view"
-        android:layout_width="match_parent"
+        android:layout_width="0dp"
-        android:layout_height="match_parent"
+        android:layout_height="0dp"
-        android:layout="@layout/group_call_call_full" />
+        android:layout="@layout/group_call_call_full"
+        app:layout_constraintBottom_toTopOf="@id/fold_top_guideline"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
 
     <androidx.constraintlayout.widget.ConstraintLayout
         android:id="@+id/call_screen"
         android:layout_width="match_parent"
         android:layout_height="match_parent">
 
+        <androidx.constraintlayout.widget.Guideline
+            android:id="@+id/fold_top_call_screen_guideline"
+            android:layout_width="0dp"
+            android:layout_height="0dp"
+            android:orientation="horizontal"
+            app:layout_constraintBottom_toTopOf="@id/call_screen_navigation_bar_guideline"
+            app:layout_constraintGuide_end="0dp" />
+
         <View
             android:id="@+id/call_screen_header_gradient"
             android:layout_width="match_parent"
@@ -68,19 +121,20 @@
 
         <View
             android:id="@+id/call_screen_footer_gradient"
-            android:layout_width="match_parent"
+            android:layout_width="0dp"
             android:layout_height="0dp"
             android:layout_margin="-40dp"
-            android:background="@drawable/webrtc_call_screen_header_gradient"
+            android:background="@drawable/webrtc_call_screen_footer_gradient"
-            android:rotation="180"
             android:visibility="gone"
             app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toTopOf="@id/call_screen_footer_gradient_spacer"
             tools:visibility="visible" />
 
         <androidx.recyclerview.widget.RecyclerView
             android:id="@+id/call_screen_participants_recycler"
-            android:layout_width="match_parent"
+            android:layout_width="wrap_content"
             android:layout_height="72dp"
             android:layout_marginStart="16dp"
             android:layout_marginEnd="16dp"
@@ -89,14 +143,19 @@
             android:visibility="gone"
             app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
             app:layout_constraintBottom_toTopOf="@id/call_screen_video_toggle"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintHorizontal_bias="1"
+            app:layout_constraintStart_toStartOf="parent"
             app:reverseLayout="true"
-            tools:listitem="@layout/webrtc_call_participant_recycler_item" />
+            tools:itemCount="2"
+            tools:listitem="@layout/webrtc_call_participant_recycler_item"
+            tools:visibility="visible" />
 
         <org.thoughtcrime.securesms.util.views.TouchInterceptingFrameLayout
             android:id="@+id/call_screen_pip_area"
             android:layout_width="0dp"
             android:layout_height="0dp"
-            app:layout_constraintBottom_toTopOf="@+id/call_screen_navigation_bar_guideline"
+            app:layout_constraintBottom_toTopOf="@+id/fold_top_call_screen_guideline"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toTopOf="parent">
@@ -358,6 +417,39 @@
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent" />
 
+        <LinearLayout
+            android:id="@+id/fold_show_participants_menu_counter_wrapper"
+            android:layout_width="wrap_content"
+            android:layout_height="56dp"
+            android:alpha="0"
+            android:background="?attr/selectableItemBackground"
+            android:gravity="center"
+            android:minWidth="48dp"
+            android:orientation="horizontal"
+            android:paddingStart="16dp"
+            android:paddingEnd="16dp"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/fold_top_call_screen_guideline"
+            tools:background="@color/core_ultramarine">
+
+            <androidx.appcompat.widget.AppCompatImageView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_marginEnd="4dp"
+                app:srcCompat="@drawable/ic_group_solid_24"
+                app:tint="@color/core_white" />
+
+            <TextView
+                android:id="@+id/fold_show_participants_menu_counter"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:textColor="@color/core_white"
+                android:textSize="13sp"
+                android:textStyle="bold"
+                tools:text="0" />
+
+        </LinearLayout>
+
         <androidx.constraintlayout.widget.Barrier
             android:id="@+id/call_screen_footer_gradient_barrier"
             android:layout_width="wrap_content"

app/witness-verifications.gradle

@@ -231,6 +231,9 @@ dependencyVerification {
         ['androidx.viewpager:viewpager:1.0.0',
          '147af4e14a1984010d8f155e5e19d781f03c1d70dfed02a8e0d18428b8fc8682'],
 
+        ['androidx.window:window:1.0.0-alpha09',
+         'edbaafc3a7b0977c138916585d761fe159a521177a30065d676d067edf6571d2'],
+
         ['cn.carbswang.android:NumberPickerView:1.0.9',
          '18b3c316d62c7c277978a8d4ed57a5b8f4e943762264960f579a8a549c756729'],
 
@@ -507,20 +510,23 @@ dependencyVerification {
         ['org.jetbrains.kotlin:kotlin-reflect:1.4.10',
          '3ab3413ec945f801448360ad97bc6e14fec6d606889ede3c707cc277b4467f45'],
 
-        ['org.jetbrains.kotlin:kotlin-stdlib-common:1.4.32',
+        ['org.jetbrains.kotlin:kotlin-stdlib-common:1.5.10',
-         'e1ff6f55ee9e7591dcc633f7757bac25a7edb1cc7f738b37ec652f10f66a4145'],
+         'd958ce94beda85f865829fb95012804866db7d5246615fd71a2f5aabca3e7994'],
 
-        ['org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.4.32',
+        ['org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.5.0',
-         '5f801e75ca27d8791c14b07943c608da27620d910a8093022af57f543d5d98b6'],
+         'ac12f092f12b575c1f9e0ab5025b1e610b0fe95663e26371c16c328895711bae'],
 
-        ['org.jetbrains.kotlin:kotlin-stdlib:1.4.32',
+        ['org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.5.0',
-         '13e9fd3e69dc7230ce0fc873a92a4e5d521d179bcf1bef75a6705baac3bfecba'],
+         '15e6c81b9e845eefe58d51a04670bb90418046f458264ec0e61ee9bdbc1bfae7'],
 
-        ['org.jetbrains.kotlinx:kotlinx-coroutines-android:1.4.1',
+        ['org.jetbrains.kotlin:kotlin-stdlib:1.5.10',
-         'd4cadb673b2101f1ee5fbc147956ac78b1cfd9cc255fb53d3aeb88dff11d99ca'],
+         'ca87c454cd3f2e60931f1803c59699d510d3b4b959cd7119296fb947581d722d'],
 
-        ['org.jetbrains.kotlinx:kotlinx-coroutines-core-jvm:1.4.1',
+        ['org.jetbrains.kotlinx:kotlinx-coroutines-android:1.5.0',
-         '6d2f87764b6638f27aff12ed380db4b63c9d46ba55dc32683a650598fa5a3e22'],
+         '7099198391d673c199fea084423d9f3fdc79470acba19111330c7f88504279c7'],
+
+        ['org.jetbrains.kotlinx:kotlinx-coroutines-core-jvm:1.5.0',
+         '78d6cc7135f84d692ff3752fcfd1fa1bbe0940d7df70652e4f1eaeec0c78afbb'],
 
         ['org.jetbrains:annotations:13.0',
          'ace2a10dc8e2d5fd34925ecac03e4988b2c0f851650c94b8cef49ba1bd111478'],