shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java - external/github.com/flutter/engine - Git at Google

 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 package io.flutter.plugin.platform;

 import static android.view.MotionEvent.PointerCoords;
 import static android.view.MotionEvent.PointerProperties;

 import android.annotation.TargetApi;
 import android.content.Context;
 import android.os.Build;
 import android.util.DisplayMetrics;
 import android.util.Log;
 import android.view.MotionEvent;
 import android.view.View;
 import androidx.annotation.NonNull;
 import androidx.annotation.UiThread;
 import androidx.annotation.VisibleForTesting;
 import io.flutter.embedding.engine.dart.DartExecutor;
 import io.flutter.embedding.engine.systemchannels.PlatformViewsChannel;
 import io.flutter.plugin.editing.TextInputPlugin;
 import io.flutter.view.AccessibilityBridge;
 import io.flutter.view.TextureRegistry;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;

 /**
  * Manages platform views.
  *
  * <p>Each {@link io.flutter.app.FlutterPluginRegistry} has a single platform views controller. A
  * platform views controller can be attached to at most one Flutter view.
  */
 public class PlatformViewsController implements PlatformViewsAccessibilityDelegate {
   private static final String TAG = "PlatformViewsController";

   // API level 20 is required for VirtualDisplay#setSurface which we use when resizing a platform
   // view.
   private static final int MINIMAL_SDK = Build.VERSION_CODES.KITKAT_WATCH;

   private final PlatformViewRegistryImpl registry;

   // The context of the Activity or Fragment hosting the render target for the Flutter engine.
   private Context context;

   // The View currently rendering the Flutter UI associated with these platform views.
   private View flutterView;

   // The texture registry maintaining the textures into which the embedded views will be rendered.
   private TextureRegistry textureRegistry;

   private TextInputPlugin textInputPlugin;

   // The system channel used to communicate with the framework about platform views.
   private PlatformViewsChannel platformViewsChannel;

   // The accessibility bridge to which accessibility events form the platform views will be
   // dispatched.
   private final AccessibilityEventsDelegate accessibilityEventsDelegate;

   // TODO(mattcarroll): Refactor overall platform views to facilitate testing and then make
   // this private. This is visible as a hack to facilitate testing. This was deemed the least
   // bad option at the time of writing.
   @VisibleForTesting /* package */ final HashMap<Integer, VirtualDisplayController> vdControllers;

   // Maps a virtual display's context to the platform view hosted in this virtual display.
   // Since each virtual display has it's unique context this allows associating any view with the
   // platform view that
   // it is associated with(e.g if a platform view creates other views in the same virtual display.
   private final HashMap<Context, View> contextToPlatformView;

   private final PlatformViewsChannel.PlatformViewsHandler channelHandler =
       new PlatformViewsChannel.PlatformViewsHandler() {
         @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
         @Override
         public long createPlatformView(
             @NonNull PlatformViewsChannel.PlatformViewCreationRequest request) {
           ensureValidAndroidVersion();

           if (!validateDirection(request.direction)) {
             throw new IllegalStateException(
                 "Trying to create a view with unknown direction value: "
                     + request.direction
                     + "(view id: "
                     + request.viewId
                     + ")");
           }

           if (vdControllers.containsKey(request.viewId)) {
             throw new IllegalStateException(
                 "Trying to create an already created platform view, view id: " + request.viewId);
           }

           PlatformViewFactory viewFactory = registry.getFactory(request.viewType);
           if (viewFactory == null) {
             throw new IllegalStateException(
                 "Trying to create a platform view of unregistered type: " + request.viewType);
           }

           Object createParams = null;
           if (request.params != null) {
             createParams = viewFactory.getCreateArgsCodec().decodeMessage(request.params);
           }

           int physicalWidth = toPhysicalPixels(request.logicalWidth);
           int physicalHeight = toPhysicalPixels(request.logicalHeight);
           validateVirtualDisplayDimensions(physicalWidth, physicalHeight);

           TextureRegistry.SurfaceTextureEntry textureEntry = textureRegistry.createSurfaceTexture();
           VirtualDisplayController vdController =
               VirtualDisplayController.create(
                   context,
                   accessibilityEventsDelegate,
                   viewFactory,
                   textureEntry,
                   physicalWidth,
                   physicalHeight,
                   request.viewId,
                   createParams,
                   (view, hasFocus) -> {
                     if (hasFocus) {
                       platformViewsChannel.invokeViewFocused(request.viewId);
                     }
                   });

           if (vdController == null) {
             throw new IllegalStateException(
                 "Failed creating virtual display for a "
                     + request.viewType
                     + " with id: "
                     + request.viewId);
           }

           // If our FlutterEngine is already attached to a Flutter UI, provide that Android
           // View to this new platform view.
           if (flutterView != null) {
             vdController.onFlutterViewAttached(flutterView);
           }

           vdControllers.put(request.viewId, vdController);
           View platformView = vdController.getView();
           platformView.setLayoutDirection(request.direction);
           contextToPlatformView.put(platformView.getContext(), platformView);

           // TODO(amirh): copy accessibility nodes to the FlutterView's accessibility tree.

           return textureEntry.id();
         }

         @Override
         public void disposePlatformView(int viewId) {
           ensureValidAndroidVersion();

           VirtualDisplayController vdController = vdControllers.get(viewId);
           if (vdController == null) {
             throw new IllegalStateException(
                 "Trying to dispose a platform view with unknown id: " + viewId);
           }

           if (textInputPlugin != null) {
             textInputPlugin.clearPlatformViewClient(viewId);
           }

           contextToPlatformView.remove(vdController.getView().getContext());
           vdController.dispose();
           vdControllers.remove(viewId);
         }

         @Override
         public void resizePlatformView(
             @NonNull PlatformViewsChannel.PlatformViewResizeRequest request,
             @NonNull Runnable onComplete) {
           ensureValidAndroidVersion();

           final VirtualDisplayController vdController = vdControllers.get(request.viewId);
           if (vdController == null) {
             throw new IllegalStateException(
                 "Trying to resize a platform view with unknown id: " + request.viewId);
           }

           int physicalWidth = toPhysicalPixels(request.newLogicalWidth);
           int physicalHeight = toPhysicalPixels(request.newLogicalHeight);
           validateVirtualDisplayDimensions(physicalWidth, physicalHeight);

           // Resizing involved moving the platform view to a new virtual display. Doing so
           // potentially results in losing an active input connection. To make sure we preserve
           // the input connection when resizing we lock it here and unlock after the resize is
           // complete.
           lockInputConnection(vdController);
           vdController.resize(
               physicalWidth,
               physicalHeight,
               new Runnable() {
                 @Override
                 public void run() {
                   unlockInputConnection(vdController);
                   onComplete.run();
                 }
               });
         }

         @Override
         public void onTouch(@NonNull PlatformViewsChannel.PlatformViewTouch touch) {
           ensureValidAndroidVersion();

           float density = context.getResources().getDisplayMetrics().density;
           PointerProperties[] pointerProperties =
               parsePointerPropertiesList(touch.rawPointerPropertiesList)
                   .toArray(new PointerProperties[touch.pointerCount]);
           PointerCoords[] pointerCoords =
               parsePointerCoordsList(touch.rawPointerCoords, density)
                   .toArray(new PointerCoords[touch.pointerCount]);

           if (!vdControllers.containsKey(touch.viewId)) {
             throw new IllegalStateException(
                 "Sending touch to an unknown view with id: " + touch.viewId);
           }

           MotionEvent event =
               MotionEvent.obtain(
                   touch.downTime.longValue(),
                   touch.eventTime.longValue(),
                   touch.action,
                   touch.pointerCount,
                   pointerProperties,
                   pointerCoords,
                   touch.metaState,
                   touch.buttonState,
                   touch.xPrecision,
                   touch.yPrecision,
                   touch.deviceId,
                   touch.edgeFlags,
                   touch.source,
                   touch.flags);

           vdControllers.get(touch.viewId).dispatchTouchEvent(event);
         }

         @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
         @Override
         public void setDirection(int viewId, int direction) {
           ensureValidAndroidVersion();

           if (!validateDirection(direction)) {
             throw new IllegalStateException(
                 "Trying to set unknown direction value: "
                     + direction
                     + "(view id: "
                     + viewId
                     + ")");
           }

           View view = vdControllers.get(viewId).getView();
           if (view == null) {
             throw new IllegalStateException(
                 "Sending touch to an unknown view with id: " + direction);
           }

           view.setLayoutDirection(direction);
         }

         @Override
         public void clearFocus(int viewId) {
           View view = vdControllers.get(viewId).getView();
           view.clearFocus();
         }

         private void ensureValidAndroidVersion() {
           if (Build.VERSION.SDK_INT < MINIMAL_SDK) {
             throw new IllegalStateException(
                 "Trying to use platform views with API "
                     + Build.VERSION.SDK_INT
                     + ", required API level is: "
                     + MINIMAL_SDK);
           }
         }
       };

   public PlatformViewsController() {
     registry = new PlatformViewRegistryImpl();
     vdControllers = new HashMap<>();
     accessibilityEventsDelegate = new AccessibilityEventsDelegate();
     contextToPlatformView = new HashMap<>();
   }

   /**
    * Attaches this platform views controller to its input and output channels.
    *
    * @param context The base context that will be passed to embedded views created by this
    *     controller. This should be the context of the Activity hosting the Flutter application.
    * @param textureRegistry The texture registry which provides the output textures into which the
    *     embedded views will be rendered.
    * @param dartExecutor The dart execution context, which is used to setup a system channel.
    */
   public void attach(
       Context context, TextureRegistry textureRegistry, @NonNull DartExecutor dartExecutor) {
     if (this.context != null) {
       throw new AssertionError(
           "A PlatformViewsController can only be attached to a single output target.\n"
               + "attach was called while the PlatformViewsController was already attached.");
     }
     this.context = context;
     this.textureRegistry = textureRegistry;
     platformViewsChannel = new PlatformViewsChannel(dartExecutor);
     platformViewsChannel.setPlatformViewsHandler(channelHandler);
   }

   /**
    * Detaches this platform views controller.
    *
    * <p>This is typically called when a Flutter applications moves to run in the background, or is
    * destroyed. After calling this the platform views controller will no longer listen to it's
    * previous messenger, and will not maintain references to the texture registry, context, and
    * messenger passed to the previous attach call.
    */
   @UiThread
   public void detach() {
     platformViewsChannel.setPlatformViewsHandler(null);
     platformViewsChannel = null;
     context = null;
     textureRegistry = null;
   }

   /**
    * This {@code PlatformViewsController} and its {@code FlutterEngine} is now attached to an
    * Android {@code View} that renders a Flutter UI.
    */
   public void attachToView(@NonNull View flutterView) {
     this.flutterView = flutterView;

     // Inform all existing platform views that they are now associated with
     // a Flutter View.
     for (VirtualDisplayController controller : vdControllers.values()) {
       controller.onFlutterViewAttached(flutterView);
     }
   }

   /**
    * This {@code PlatformViewController} and its {@code FlutterEngine} are no longer attached to an
    * Android {@code View} that renders a Flutter UI.
    *
    * <p>All platform views controlled by this {@code PlatformViewController} will be detached from
    * the previously attached {@code View}.
    */
   public void detachFromView() {
     this.flutterView = null;

     // Inform all existing platform views that they are no longer associated with
     // a Flutter View.
     for (VirtualDisplayController controller : vdControllers.values()) {
       controller.onFlutterViewDetached();
     }
   }

   @Override
   public void attachAccessibilityBridge(AccessibilityBridge accessibilityBridge) {
     accessibilityEventsDelegate.setAccessibilityBridge(accessibilityBridge);
   }

   @Override
   public void detachAccessibiltyBridge() {
     accessibilityEventsDelegate.setAccessibilityBridge(null);
   }

   /**
    * Attaches this controller to a text input plugin.
    *
    * <p>While a text input plugin is available, the platform views controller interacts with it to
    * facilitate delegation of text input connections to platform views.
    *
    * <p>A platform views controller should be attached to a text input plugin whenever it is
    * possible for the Flutter framework to receive text input.
    */
   public void attachTextInputPlugin(TextInputPlugin textInputPlugin) {
     this.textInputPlugin = textInputPlugin;
   }

   /** Detaches this controller from the currently attached text input plugin. */
   public void detachTextInputPlugin() {
     textInputPlugin = null;
   }

   /**
    * Returns true if Flutter should perform input connection proxying for the view.
    *
    * <p>If the view is a platform view managed by this platform views controller returns true. Else
    * if the view was created in a platform view's VD, delegates the decision to the platform view's
    * {@link View#checkInputConnectionProxy(View)} method. Else returns false.
    */
   public boolean checkInputConnectionProxy(View view) {
     if (!contextToPlatformView.containsKey(view.getContext())) {
       return false;
     }
     View platformView = contextToPlatformView.get(view.getContext());
     if (platformView == view) {
       return true;
     }
     return platformView.checkInputConnectionProxy(view);
   }

   public PlatformViewRegistry getRegistry() {
     return registry;
   }

   /**
    * Invoked when the {@link io.flutter.embedding.engine.FlutterEngine} that owns this {@link
    * PlatformViewsController} attaches to JNI.
    */
   public void onAttachedToJNI() {
     // Currently no action needs to be taken after JNI attachment.
   }

   /**
    * Invoked when the {@link io.flutter.embedding.engine.FlutterEngine} that owns this {@link
    * PlatformViewsController} detaches from JNI.
    */
   public void onDetachedFromJNI() {
     // Dispose all virtual displays so that any future updates to textures will not be
     // propagated to the native peer.
     flushAllViews();
   }

   public void onPreEngineRestart() {
     flushAllViews();
   }

   @Override
   public View getPlatformViewById(Integer id) {
     VirtualDisplayController controller = vdControllers.get(id);
     if (controller == null) {
       return null;
     }
     return controller.getView();
   }

   private void lockInputConnection(@NonNull VirtualDisplayController controller) {
     if (textInputPlugin == null) {
       return;
     }
     textInputPlugin.lockPlatformViewInputConnection();
     controller.onInputConnectionLocked();
   }

   private void unlockInputConnection(@NonNull VirtualDisplayController controller) {
     if (textInputPlugin == null) {
       return;
     }
     textInputPlugin.unlockPlatformViewInputConnection();
     controller.onInputConnectionUnlocked();
   }

   private static boolean validateDirection(int direction) {
     return direction == View.LAYOUT_DIRECTION_LTR || direction == View.LAYOUT_DIRECTION_RTL;
   }

   @SuppressWarnings("unchecked")
   private static List<PointerProperties> parsePointerPropertiesList(Object rawPropertiesList) {
     List<Object> rawProperties = (List<Object>) rawPropertiesList;
     List<PointerProperties> pointerProperties = new ArrayList<>();
     for (Object o : rawProperties) {
       pointerProperties.add(parsePointerProperties(o));
     }
     return pointerProperties;
   }

   @SuppressWarnings("unchecked")
   private static PointerProperties parsePointerProperties(Object rawProperties) {
     List<Object> propertiesList = (List<Object>) rawProperties;
     PointerProperties properties = new MotionEvent.PointerProperties();
     properties.id = (int) propertiesList.get(0);
     properties.toolType = (int) propertiesList.get(1);
     return properties;
   }

   @SuppressWarnings("unchecked")
   private static List<PointerCoords> parsePointerCoordsList(Object rawCoordsList, float density) {
     List<Object> rawCoords = (List<Object>) rawCoordsList;
     List<PointerCoords> pointerCoords = new ArrayList<>();
     for (Object o : rawCoords) {
       pointerCoords.add(parsePointerCoords(o, density));
     }
     return pointerCoords;
   }

   @SuppressWarnings("unchecked")
   private static PointerCoords parsePointerCoords(Object rawCoords, float density) {
     List<Object> coordsList = (List<Object>) rawCoords;
     PointerCoords coords = new MotionEvent.PointerCoords();
     coords.orientation = (float) (double) coordsList.get(0);
     coords.pressure = (float) (double) coordsList.get(1);
     coords.size = (float) (double) coordsList.get(2);
     coords.toolMajor = (float) (double) coordsList.get(3) * density;
     coords.toolMinor = (float) (double) coordsList.get(4) * density;
     coords.touchMajor = (float) (double) coordsList.get(5) * density;
     coords.touchMinor = (float) (double) coordsList.get(6) * density;
     coords.x = (float) (double) coordsList.get(7) * density;
     coords.y = (float) (double) coordsList.get(8) * density;
     return coords;
   }

   // Creating a VirtualDisplay larger than the size of the device screen size
   // could cause the device to restart: https://github.com/flutter/flutter/issues/28978
   private void validateVirtualDisplayDimensions(int width, int height) {
     DisplayMetrics metrics = context.getResources().getDisplayMetrics();
     if (height > metrics.heightPixels || width > metrics.widthPixels) {
       String message =
           "Creating a virtual display of size: "
               + "["
               + width
               + ", "
               + height
               + "] may result in problems"
               + "(https://github.com/flutter/flutter/issues/2897)."
               + "It is larger than the device screen size: "
               + "["
               + metrics.widthPixels
               + ", "
               + metrics.heightPixels
               + "].";
       Log.w(TAG, message);
     }
   }

   private int toPhysicalPixels(double logicalPixels) {
     float density = context.getResources().getDisplayMetrics().density;
     return (int) Math.round(logicalPixels * density);
   }

   private void flushAllViews() {
     for (VirtualDisplayController controller : vdControllers.values()) {
       controller.dispose();
     }
     vdControllers.clear();
   }
 }
	// Copyright 2013 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	package io.flutter.plugin.platform;

	import static android.view.MotionEvent.PointerCoords;
	import static android.view.MotionEvent.PointerProperties;

	import android.annotation.TargetApi;
	import android.content.Context;
	import android.os.Build;
	import android.util.DisplayMetrics;
	import android.util.Log;
	import android.view.MotionEvent;
	import android.view.View;
	import androidx.annotation.NonNull;
	import androidx.annotation.UiThread;
	import androidx.annotation.VisibleForTesting;
	import io.flutter.embedding.engine.dart.DartExecutor;
	import io.flutter.embedding.engine.systemchannels.PlatformViewsChannel;
	import io.flutter.plugin.editing.TextInputPlugin;
	import io.flutter.view.AccessibilityBridge;
	import io.flutter.view.TextureRegistry;
	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.List;

	/**
	* Manages platform views.
	*
	* <p>Each {@link io.flutter.app.FlutterPluginRegistry} has a single platform views controller. A
	* platform views controller can be attached to at most one Flutter view.
	*/
	public class PlatformViewsController implements PlatformViewsAccessibilityDelegate {
	private static final String TAG = "PlatformViewsController";

	// API level 20 is required for VirtualDisplay#setSurface which we use when resizing a platform
	// view.
	private static final int MINIMAL_SDK = Build.VERSION_CODES.KITKAT_WATCH;

	private final PlatformViewRegistryImpl registry;

	// The context of the Activity or Fragment hosting the render target for the Flutter engine.
	private Context context;

	// The View currently rendering the Flutter UI associated with these platform views.
	private View flutterView;

	// The texture registry maintaining the textures into which the embedded views will be rendered.
	private TextureRegistry textureRegistry;

	private TextInputPlugin textInputPlugin;

	// The system channel used to communicate with the framework about platform views.
	private PlatformViewsChannel platformViewsChannel;

	// The accessibility bridge to which accessibility events form the platform views will be
	// dispatched.
	private final AccessibilityEventsDelegate accessibilityEventsDelegate;

	// TODO(mattcarroll): Refactor overall platform views to facilitate testing and then make
	// this private. This is visible as a hack to facilitate testing. This was deemed the least
	// bad option at the time of writing.
	@VisibleForTesting /* package */ final HashMap<Integer, VirtualDisplayController> vdControllers;

	// Maps a virtual display's context to the platform view hosted in this virtual display.
	// Since each virtual display has it's unique context this allows associating any view with the
	// platform view that
	// it is associated with(e.g if a platform view creates other views in the same virtual display.
	private final HashMap<Context, View> contextToPlatformView;

	private final PlatformViewsChannel.PlatformViewsHandler channelHandler =
	new PlatformViewsChannel.PlatformViewsHandler() {
	@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
	@Override
	public long createPlatformView(
	@NonNull PlatformViewsChannel.PlatformViewCreationRequest request) {
	ensureValidAndroidVersion();

	if (!validateDirection(request.direction)) {
	throw new IllegalStateException(
	"Trying to create a view with unknown direction value: "
	+ request.direction
	+ "(view id: "
	+ request.viewId
	+ ")");
	}

	if (vdControllers.containsKey(request.viewId)) {
	throw new IllegalStateException(
	"Trying to create an already created platform view, view id: " + request.viewId);
	}

	PlatformViewFactory viewFactory = registry.getFactory(request.viewType);
	if (viewFactory == null) {
	throw new IllegalStateException(
	"Trying to create a platform view of unregistered type: " + request.viewType);
	}

	Object createParams = null;
	if (request.params != null) {
	createParams = viewFactory.getCreateArgsCodec().decodeMessage(request.params);
	}

	int physicalWidth = toPhysicalPixels(request.logicalWidth);
	int physicalHeight = toPhysicalPixels(request.logicalHeight);
	validateVirtualDisplayDimensions(physicalWidth, physicalHeight);

	TextureRegistry.SurfaceTextureEntry textureEntry = textureRegistry.createSurfaceTexture();
	VirtualDisplayController vdController =
	VirtualDisplayController.create(
	context,
	accessibilityEventsDelegate,
	viewFactory,
	textureEntry,
	physicalWidth,
	physicalHeight,
	request.viewId,
	createParams,
	(view, hasFocus) -> {
	if (hasFocus) {
	platformViewsChannel.invokeViewFocused(request.viewId);
	}
	});

	if (vdController == null) {
	throw new IllegalStateException(
	"Failed creating virtual display for a "
	+ request.viewType
	+ " with id: "
	+ request.viewId);
	}

	// If our FlutterEngine is already attached to a Flutter UI, provide that Android
	// View to this new platform view.
	if (flutterView != null) {
	vdController.onFlutterViewAttached(flutterView);
	}

	vdControllers.put(request.viewId, vdController);
	View platformView = vdController.getView();
	platformView.setLayoutDirection(request.direction);
	contextToPlatformView.put(platformView.getContext(), platformView);

	// TODO(amirh): copy accessibility nodes to the FlutterView's accessibility tree.

	return textureEntry.id();
	}

	@Override
	public void disposePlatformView(int viewId) {
	ensureValidAndroidVersion();

	VirtualDisplayController vdController = vdControllers.get(viewId);
	if (vdController == null) {
	throw new IllegalStateException(
	"Trying to dispose a platform view with unknown id: " + viewId);
	}

	if (textInputPlugin != null) {
	textInputPlugin.clearPlatformViewClient(viewId);
	}

	contextToPlatformView.remove(vdController.getView().getContext());
	vdController.dispose();
	vdControllers.remove(viewId);
	}

	@Override
	public void resizePlatformView(
	@NonNull PlatformViewsChannel.PlatformViewResizeRequest request,
	@NonNull Runnable onComplete) {
	ensureValidAndroidVersion();

	final VirtualDisplayController vdController = vdControllers.get(request.viewId);
	if (vdController == null) {
	throw new IllegalStateException(
	"Trying to resize a platform view with unknown id: " + request.viewId);
	}

	int physicalWidth = toPhysicalPixels(request.newLogicalWidth);
	int physicalHeight = toPhysicalPixels(request.newLogicalHeight);
	validateVirtualDisplayDimensions(physicalWidth, physicalHeight);

	// Resizing involved moving the platform view to a new virtual display. Doing so
	// potentially results in losing an active input connection. To make sure we preserve
	// the input connection when resizing we lock it here and unlock after the resize is
	// complete.
	lockInputConnection(vdController);
	vdController.resize(
	physicalWidth,
	physicalHeight,
	new Runnable() {
	@Override
	public void run() {
	unlockInputConnection(vdController);
	onComplete.run();
	}
	});
	}

	@Override
	public void onTouch(@NonNull PlatformViewsChannel.PlatformViewTouch touch) {
	ensureValidAndroidVersion();

	float density = context.getResources().getDisplayMetrics().density;
	PointerProperties[] pointerProperties =
	parsePointerPropertiesList(touch.rawPointerPropertiesList)
	.toArray(new PointerProperties[touch.pointerCount]);
	PointerCoords[] pointerCoords =
	parsePointerCoordsList(touch.rawPointerCoords, density)
	.toArray(new PointerCoords[touch.pointerCount]);

	if (!vdControllers.containsKey(touch.viewId)) {
	throw new IllegalStateException(
	"Sending touch to an unknown view with id: " + touch.viewId);
	}

	MotionEvent event =
	MotionEvent.obtain(
	touch.downTime.longValue(),
	touch.eventTime.longValue(),
	touch.action,
	touch.pointerCount,
	pointerProperties,
	pointerCoords,
	touch.metaState,
	touch.buttonState,
	touch.xPrecision,
	touch.yPrecision,
	touch.deviceId,
	touch.edgeFlags,
	touch.source,
	touch.flags);

	vdControllers.get(touch.viewId).dispatchTouchEvent(event);
	}

	@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
	@Override
	public void setDirection(int viewId, int direction) {
	ensureValidAndroidVersion();

	if (!validateDirection(direction)) {
	throw new IllegalStateException(
	"Trying to set unknown direction value: "
	+ direction
	+ "(view id: "
	+ viewId
	+ ")");
	}

	View view = vdControllers.get(viewId).getView();
	if (view == null) {
	throw new IllegalStateException(
	"Sending touch to an unknown view with id: " + direction);
	}

	view.setLayoutDirection(direction);
	}

	@Override
	public void clearFocus(int viewId) {
	View view = vdControllers.get(viewId).getView();
	view.clearFocus();
	}

	private void ensureValidAndroidVersion() {
	if (Build.VERSION.SDK_INT < MINIMAL_SDK) {
	throw new IllegalStateException(
	"Trying to use platform views with API "
	+ Build.VERSION.SDK_INT
	+ ", required API level is: "
	+ MINIMAL_SDK);
	}
	}
	};

	public PlatformViewsController() {
	registry = new PlatformViewRegistryImpl();
	vdControllers = new HashMap<>();
	accessibilityEventsDelegate = new AccessibilityEventsDelegate();
	contextToPlatformView = new HashMap<>();
	}

	/**
	* Attaches this platform views controller to its input and output channels.
	*
	* @param context The base context that will be passed to embedded views created by this
	* controller. This should be the context of the Activity hosting the Flutter application.
	* @param textureRegistry The texture registry which provides the output textures into which the
	* embedded views will be rendered.
	* @param dartExecutor The dart execution context, which is used to setup a system channel.
	*/
	public void attach(
	Context context, TextureRegistry textureRegistry, @NonNull DartExecutor dartExecutor) {
	if (this.context != null) {
	throw new AssertionError(
	"A PlatformViewsController can only be attached to a single output target.\n"
	+ "attach was called while the PlatformViewsController was already attached.");
	}
	this.context = context;
	this.textureRegistry = textureRegistry;
	platformViewsChannel = new PlatformViewsChannel(dartExecutor);
	platformViewsChannel.setPlatformViewsHandler(channelHandler);
	}

	/**
	* Detaches this platform views controller.
	*
	* <p>This is typically called when a Flutter applications moves to run in the background, or is
	* destroyed. After calling this the platform views controller will no longer listen to it's
	* previous messenger, and will not maintain references to the texture registry, context, and
	* messenger passed to the previous attach call.
	*/
	@UiThread
	public void detach() {
	platformViewsChannel.setPlatformViewsHandler(null);
	platformViewsChannel = null;
	context = null;
	textureRegistry = null;
	}

	/**
	* This {@code PlatformViewsController} and its {@code FlutterEngine} is now attached to an
	* Android {@code View} that renders a Flutter UI.
	*/
	public void attachToView(@NonNull View flutterView) {
	this.flutterView = flutterView;

	// Inform all existing platform views that they are now associated with
	// a Flutter View.
	for (VirtualDisplayController controller : vdControllers.values()) {
	controller.onFlutterViewAttached(flutterView);
	}
	}

	/**
	* This {@code PlatformViewController} and its {@code FlutterEngine} are no longer attached to an
	* Android {@code View} that renders a Flutter UI.
	*
	* <p>All platform views controlled by this {@code PlatformViewController} will be detached from
	* the previously attached {@code View}.
	*/
	public void detachFromView() {
	this.flutterView = null;

	// Inform all existing platform views that they are no longer associated with
	// a Flutter View.
	for (VirtualDisplayController controller : vdControllers.values()) {
	controller.onFlutterViewDetached();
	}
	}

	@Override
	public void attachAccessibilityBridge(AccessibilityBridge accessibilityBridge) {
	accessibilityEventsDelegate.setAccessibilityBridge(accessibilityBridge);
	}

	@Override
	public void detachAccessibiltyBridge() {
	accessibilityEventsDelegate.setAccessibilityBridge(null);
	}

	/**
	* Attaches this controller to a text input plugin.
	*
	* <p>While a text input plugin is available, the platform views controller interacts with it to
	* facilitate delegation of text input connections to platform views.
	*
	* <p>A platform views controller should be attached to a text input plugin whenever it is
	* possible for the Flutter framework to receive text input.
	*/
	public void attachTextInputPlugin(TextInputPlugin textInputPlugin) {
	this.textInputPlugin = textInputPlugin;
	}

	/** Detaches this controller from the currently attached text input plugin. */
	public void detachTextInputPlugin() {
	textInputPlugin = null;
	}

	/**
	* Returns true if Flutter should perform input connection proxying for the view.
	*
	* <p>If the view is a platform view managed by this platform views controller returns true. Else
	* if the view was created in a platform view's VD, delegates the decision to the platform view's
	* {@link View#checkInputConnectionProxy(View)} method. Else returns false.
	*/
	public boolean checkInputConnectionProxy(View view) {
	if (!contextToPlatformView.containsKey(view.getContext())) {
	return false;
	}
	View platformView = contextToPlatformView.get(view.getContext());
	if (platformView == view) {
	return true;
	}
	return platformView.checkInputConnectionProxy(view);
	}

	public PlatformViewRegistry getRegistry() {
	return registry;
	}

	/**
	* Invoked when the {@link io.flutter.embedding.engine.FlutterEngine} that owns this {@link
	* PlatformViewsController} attaches to JNI.
	*/
	public void onAttachedToJNI() {
	// Currently no action needs to be taken after JNI attachment.
	}

	/**
	* Invoked when the {@link io.flutter.embedding.engine.FlutterEngine} that owns this {@link
	* PlatformViewsController} detaches from JNI.
	*/
	public void onDetachedFromJNI() {
	// Dispose all virtual displays so that any future updates to textures will not be
	// propagated to the native peer.
	flushAllViews();
	}

	public void onPreEngineRestart() {
	flushAllViews();
	}

	@Override
	public View getPlatformViewById(Integer id) {
	VirtualDisplayController controller = vdControllers.get(id);
	if (controller == null) {
	return null;
	}
	return controller.getView();
	}

	private void lockInputConnection(@NonNull VirtualDisplayController controller) {
	if (textInputPlugin == null) {
	return;
	}
	textInputPlugin.lockPlatformViewInputConnection();
	controller.onInputConnectionLocked();
	}

	private void unlockInputConnection(@NonNull VirtualDisplayController controller) {
	if (textInputPlugin == null) {
	return;
	}
	textInputPlugin.unlockPlatformViewInputConnection();
	controller.onInputConnectionUnlocked();
	}

	private static boolean validateDirection(int direction) {
	return direction == View.LAYOUT_DIRECTION_LTR \|\| direction == View.LAYOUT_DIRECTION_RTL;
	}

	@SuppressWarnings("unchecked")
	private static List<PointerProperties> parsePointerPropertiesList(Object rawPropertiesList) {
	List<Object> rawProperties = (List<Object>) rawPropertiesList;
	List<PointerProperties> pointerProperties = new ArrayList<>();
	for (Object o : rawProperties) {
	pointerProperties.add(parsePointerProperties(o));
	}
	return pointerProperties;
	}

	@SuppressWarnings("unchecked")
	private static PointerProperties parsePointerProperties(Object rawProperties) {
	List<Object> propertiesList = (List<Object>) rawProperties;
	PointerProperties properties = new MotionEvent.PointerProperties();
	properties.id = (int) propertiesList.get(0);
	properties.toolType = (int) propertiesList.get(1);
	return properties;
	}

	@SuppressWarnings("unchecked")
	private static List<PointerCoords> parsePointerCoordsList(Object rawCoordsList, float density) {
	List<Object> rawCoords = (List<Object>) rawCoordsList;
	List<PointerCoords> pointerCoords = new ArrayList<>();
	for (Object o : rawCoords) {
	pointerCoords.add(parsePointerCoords(o, density));
	}
	return pointerCoords;
	}

	@SuppressWarnings("unchecked")
	private static PointerCoords parsePointerCoords(Object rawCoords, float density) {
	List<Object> coordsList = (List<Object>) rawCoords;
	PointerCoords coords = new MotionEvent.PointerCoords();
	coords.orientation = (float) (double) coordsList.get(0);
	coords.pressure = (float) (double) coordsList.get(1);
	coords.size = (float) (double) coordsList.get(2);
	coords.toolMajor = (float) (double) coordsList.get(3) * density;
	coords.toolMinor = (float) (double) coordsList.get(4) * density;
	coords.touchMajor = (float) (double) coordsList.get(5) * density;
	coords.touchMinor = (float) (double) coordsList.get(6) * density;
	coords.x = (float) (double) coordsList.get(7) * density;
	coords.y = (float) (double) coordsList.get(8) * density;
	return coords;
	}

	// Creating a VirtualDisplay larger than the size of the device screen size
	// could cause the device to restart: https://github.com/flutter/flutter/issues/28978
	private void validateVirtualDisplayDimensions(int width, int height) {
	DisplayMetrics metrics = context.getResources().getDisplayMetrics();
	if (height > metrics.heightPixels \|\| width > metrics.widthPixels) {
	String message =
	"Creating a virtual display of size: "
	+ "["
	+ width
	+ ", "
	+ height
	+ "] may result in problems"
	+ "(https://github.com/flutter/flutter/issues/2897)."
	+ "It is larger than the device screen size: "
	+ "["
	+ metrics.widthPixels
	+ ", "
	+ metrics.heightPixels
	+ "].";
	Log.w(TAG, message);
	}
	}

	private int toPhysicalPixels(double logicalPixels) {
	float density = context.getResources().getDisplayMetrics().density;
	return (int) Math.round(logicalPixels * density);
	}

	private void flushAllViews() {
	for (VirtualDisplayController controller : vdControllers.values()) {
	controller.dispose();
	}
	vdControllers.clear();
	}
	}