shell/platform/android/io/flutter/embedding/android/FlutterImageView.java - mirrors/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.embedding.android;

 import static io.flutter.Build.API_LEVELS;

 import android.annotation.SuppressLint;
 import android.annotation.TargetApi;
 import android.content.Context;
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
 import android.graphics.ColorSpace;
 import android.graphics.PixelFormat;
 import android.hardware.HardwareBuffer;
 import android.media.Image;
 import android.media.Image.Plane;
 import android.media.ImageReader;
 import android.util.AttributeSet;
 import android.view.Surface;
 import android.view.View;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;
 import io.flutter.Log;
 import io.flutter.embedding.engine.renderer.FlutterRenderer;
 import io.flutter.embedding.engine.renderer.RenderSurface;
 import java.nio.ByteBuffer;
 import java.util.Locale;

 /**
  * Paints a Flutter UI provided by an {@link android.media.ImageReader} onto a {@link
  * android.graphics.Canvas}.
  *
  * <p>A {@code FlutterImageView} is intended for situations where a developer needs to render a
  * Flutter UI, but also needs to render an interactive {@link
  * io.flutter.plugin.platform.PlatformView}.
  *
  * <p>This {@code View} takes an {@link android.media.ImageReader} that provides the Flutter UI in
  * an {@link android.media.Image} and renders it to the {@link android.graphics.Canvas} in {@code
  * onDraw}.
  */
 public class FlutterImageView extends View implements RenderSurface {
   private static final String TAG = "FlutterImageView";

   @NonNull private ImageReader imageReader;
   @Nullable private Image currentImage;
   @Nullable private Bitmap currentBitmap;
   @Nullable private FlutterRenderer flutterRenderer;

   public ImageReader getImageReader() {
     return imageReader;
   }

   public enum SurfaceKind {
     /** Displays the background canvas. */
     background,

     /** Displays the overlay surface canvas. */
     overlay,
   }

   /** The kind of surface. */
   private SurfaceKind kind;

   /** Whether the view is attached to the Flutter render. */
   private boolean isAttachedToFlutterRenderer = false;

   /**
    * Constructs a {@code FlutterImageView} with an {@link android.media.ImageReader} that provides
    * the Flutter UI.
    */
   public FlutterImageView(@NonNull Context context, int width, int height, SurfaceKind kind) {
     this(context, createImageReader(width, height), kind);
   }

   public FlutterImageView(@NonNull Context context) {
     this(context, 1, 1, SurfaceKind.background);
   }

   public FlutterImageView(@NonNull Context context, @NonNull AttributeSet attrs) {
     this(context, 1, 1, SurfaceKind.background);
   }

   @VisibleForTesting
   /*package*/ FlutterImageView(
       @NonNull Context context, @NonNull ImageReader imageReader, SurfaceKind kind) {
     super(context, null);
     this.imageReader = imageReader;
     this.kind = kind;
     init();
   }

   private void init() {
     setAlpha(0.0f);
   }

   private static void logW(String format, Object... args) {
     Log.w(TAG, String.format(Locale.US, format, args));
   }

   @SuppressLint("WrongConstant") // RGBA_8888 is a valid constant.
   @NonNull
   private static ImageReader createImageReader(int width, int height) {
     if (width <= 0) {
       logW("ImageReader width must be greater than 0, but given width=%d, set width=1", width);
       width = 1;
     }
     if (height <= 0) {
       logW("ImageReader height must be greater than 0, but given height=%d, set height=1", height);
       height = 1;
     }
     if (android.os.Build.VERSION.SDK_INT >= API_LEVELS.API_29) {
       return ImageReader.newInstance(
           width,
           height,
           PixelFormat.RGBA_8888,
           3,
           HardwareBuffer.USAGE_GPU_SAMPLED_IMAGE | HardwareBuffer.USAGE_GPU_COLOR_OUTPUT);
     } else {
       return ImageReader.newInstance(width, height, PixelFormat.RGBA_8888, 3);
     }
   }

   @NonNull
   public Surface getSurface() {
     return imageReader.getSurface();
   }

   @Nullable
   @Override
   public FlutterRenderer getAttachedRenderer() {
     return flutterRenderer;
   }

   /**
    * Invoked by the owner of this {@code FlutterImageView} when it wants to begin rendering a
    * Flutter UI to this {@code FlutterImageView}.
    */
   @Override
   public void attachToRenderer(@NonNull FlutterRenderer flutterRenderer) {
     switch (kind) {
       case background:
         flutterRenderer.swapSurface(imageReader.getSurface());
         break;
       case overlay:
         // Do nothing since the attachment is done by the handler of
         // `FlutterJNI#createOverlaySurface()` in the native side.
         break;
     }
     setAlpha(1.0f);
     this.flutterRenderer = flutterRenderer;
     isAttachedToFlutterRenderer = true;
   }

   /**
    * Invoked by the owner of this {@code FlutterImageView} when it no longer wants to render a
    * Flutter UI to this {@code FlutterImageView}.
    */
   public void detachFromRenderer() {
     if (!isAttachedToFlutterRenderer) {
       return;
     }
     setAlpha(0.0f);
     // Drop the latest image as it shouldn't render this image if this view is
     // attached to the renderer again.
     acquireLatestImage();
     // Clear drawings.
     currentBitmap = null;

     // Close and clear the current image if any.
     closeCurrentImage();
     invalidate();
     isAttachedToFlutterRenderer = false;
   }

   public void pause() {
     // Not supported.
   }

   public void resume() {
     // Not supported.
   }

   /**
    * Acquires the next image to be drawn to the {@link android.graphics.Canvas}. Returns true if
    * there's an image available in the queue.
    */
   public boolean acquireLatestImage() {
     if (!isAttachedToFlutterRenderer) {
       return false;
     }
     // 1. `acquireLatestImage()` may return null if no new image is available.
     // 2. There's no guarantee that `onDraw()` is called after `invalidate()`.
     // For example, the device may not produce new frames if it's in sleep mode
     // or some special Android devices so the calls to `invalidate()` queued up
     // until the device produces a new frame.
     // 3. While the engine will also stop producing frames, there is a race condition.
     final Image newImage = imageReader.acquireLatestImage();
     if (newImage != null) {
       // Only close current image after acquiring valid new image
       closeCurrentImage();
       currentImage = newImage;
       invalidate();
     }
     return newImage != null;
   }

   /** Creates a new image reader with the provided size. */
   public void resizeIfNeeded(int width, int height) {
     if (flutterRenderer == null) {
       return;
     }
     if (width == imageReader.getWidth() && height == imageReader.getHeight()) {
       return;
     }

     // Close resources.
     closeCurrentImage();
     // Close the current image reader, then create a new one with the new size.
     // Image readers cannot be resized once created.
     closeImageReader();
     imageReader = createImageReader(width, height);
   }

   /**
    * Closes the image reader associated with the current {@code FlutterImageView}.
    *
    * <p>Once the image reader is closed, calling {@code acquireLatestImage} will result in an {@code
    * IllegalStateException}.
    */
   public void closeImageReader() {
     imageReader.close();
   }

   @Override
   protected void onDraw(Canvas canvas) {
     super.onDraw(canvas);
     if (currentImage != null) {
       updateCurrentBitmap();
     }
     if (currentBitmap != null) {
       canvas.drawBitmap(currentBitmap, 0, 0, null);
     }
   }

   private void closeCurrentImage() {
     // Close and clear the current image if any.
     if (currentImage != null) {
       currentImage.close();
       currentImage = null;
     }
   }

   @TargetApi(API_LEVELS.API_29)
   private void updateCurrentBitmap() {
     if (android.os.Build.VERSION.SDK_INT >= API_LEVELS.API_29) {
       final HardwareBuffer buffer = currentImage.getHardwareBuffer();
       currentBitmap = Bitmap.wrapHardwareBuffer(buffer, ColorSpace.get(ColorSpace.Named.SRGB));
       buffer.close();
     } else {
       final Plane[] imagePlanes = currentImage.getPlanes();
       if (imagePlanes.length != 1) {
         return;
       }

       final Plane imagePlane = imagePlanes[0];
       final int desiredWidth = imagePlane.getRowStride() / imagePlane.getPixelStride();
       final int desiredHeight = currentImage.getHeight();

       if (currentBitmap == null
           || currentBitmap.getWidth() != desiredWidth
           || currentBitmap.getHeight() != desiredHeight) {
         currentBitmap =
             Bitmap.createBitmap(
                 desiredWidth, desiredHeight, android.graphics.Bitmap.Config.ARGB_8888);
       }
       ByteBuffer buffer = imagePlane.getBuffer();
       buffer.rewind();
       currentBitmap.copyPixelsFromBuffer(buffer);
     }
   }

   @Override
   protected void onSizeChanged(int width, int height, int oldWidth, int oldHeight) {
     if (width == imageReader.getWidth() && height == imageReader.getHeight()) {
       return;
     }
     // `SurfaceKind.overlay` isn't resized. Instead, the `FlutterImageView` instance
     // is destroyed. As a result, an instance with the new size is created by the surface
     // pool in the native side.
     if (kind == SurfaceKind.background && isAttachedToFlutterRenderer) {
       resizeIfNeeded(width, height);
       // Bind native window to the new surface, and create a new onscreen surface
       // with the new size in the native side.
       flutterRenderer.swapSurface(imageReader.getSurface());
     }
   }
 }
	// 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.embedding.android;

	import static io.flutter.Build.API_LEVELS;

	import android.annotation.SuppressLint;
	import android.annotation.TargetApi;
	import android.content.Context;
	import android.graphics.Bitmap;
	import android.graphics.Canvas;
	import android.graphics.ColorSpace;
	import android.graphics.PixelFormat;
	import android.hardware.HardwareBuffer;
	import android.media.Image;
	import android.media.Image.Plane;
	import android.media.ImageReader;
	import android.util.AttributeSet;
	import android.view.Surface;
	import android.view.View;
	import androidx.annotation.NonNull;
	import androidx.annotation.Nullable;
	import androidx.annotation.VisibleForTesting;
	import io.flutter.Log;
	import io.flutter.embedding.engine.renderer.FlutterRenderer;
	import io.flutter.embedding.engine.renderer.RenderSurface;
	import java.nio.ByteBuffer;
	import java.util.Locale;

	/**
	* Paints a Flutter UI provided by an {@link android.media.ImageReader} onto a {@link
	* android.graphics.Canvas}.
	*
	* <p>A {@code FlutterImageView} is intended for situations where a developer needs to render a
	* Flutter UI, but also needs to render an interactive {@link
	* io.flutter.plugin.platform.PlatformView}.
	*
	* <p>This {@code View} takes an {@link android.media.ImageReader} that provides the Flutter UI in
	* an {@link android.media.Image} and renders it to the {@link android.graphics.Canvas} in {@code
	* onDraw}.
	*/
	public class FlutterImageView extends View implements RenderSurface {
	private static final String TAG = "FlutterImageView";

	@NonNull private ImageReader imageReader;
	@Nullable private Image currentImage;
	@Nullable private Bitmap currentBitmap;
	@Nullable private FlutterRenderer flutterRenderer;

	public ImageReader getImageReader() {
	return imageReader;
	}

	public enum SurfaceKind {
	/** Displays the background canvas. */
	background,

	/** Displays the overlay surface canvas. */
	overlay,
	}

	/** The kind of surface. */
	private SurfaceKind kind;

	/** Whether the view is attached to the Flutter render. */
	private boolean isAttachedToFlutterRenderer = false;

	/**
	* Constructs a {@code FlutterImageView} with an {@link android.media.ImageReader} that provides
	* the Flutter UI.
	*/
	public FlutterImageView(@NonNull Context context, int width, int height, SurfaceKind kind) {
	this(context, createImageReader(width, height), kind);
	}

	public FlutterImageView(@NonNull Context context) {
	this(context, 1, 1, SurfaceKind.background);
	}

	public FlutterImageView(@NonNull Context context, @NonNull AttributeSet attrs) {
	this(context, 1, 1, SurfaceKind.background);
	}

	@VisibleForTesting
	/package/ FlutterImageView(
	@NonNull Context context, @NonNull ImageReader imageReader, SurfaceKind kind) {
	super(context, null);
	this.imageReader = imageReader;
	this.kind = kind;
	init();
	}

	private void init() {
	setAlpha(0.0f);
	}

	private static void logW(String format, Object... args) {
	Log.w(TAG, String.format(Locale.US, format, args));
	}

	@SuppressLint("WrongConstant") // RGBA_8888 is a valid constant.
	@NonNull
	private static ImageReader createImageReader(int width, int height) {
	if (width <= 0) {
	logW("ImageReader width must be greater than 0, but given width=%d, set width=1", width);
	width = 1;
	}
	if (height <= 0) {
	logW("ImageReader height must be greater than 0, but given height=%d, set height=1", height);
	height = 1;
	}
	if (android.os.Build.VERSION.SDK_INT >= API_LEVELS.API_29) {
	return ImageReader.newInstance(
	width,
	height,
	PixelFormat.RGBA_8888,
	3,
	HardwareBuffer.USAGE_GPU_SAMPLED_IMAGE \| HardwareBuffer.USAGE_GPU_COLOR_OUTPUT);
	} else {
	return ImageReader.newInstance(width, height, PixelFormat.RGBA_8888, 3);
	}
	}

	@NonNull
	public Surface getSurface() {
	return imageReader.getSurface();
	}

	@Nullable
	@Override
	public FlutterRenderer getAttachedRenderer() {
	return flutterRenderer;
	}

	/**
	* Invoked by the owner of this {@code FlutterImageView} when it wants to begin rendering a
	* Flutter UI to this {@code FlutterImageView}.
	*/
	@Override
	public void attachToRenderer(@NonNull FlutterRenderer flutterRenderer) {
	switch (kind) {
	case background:
	flutterRenderer.swapSurface(imageReader.getSurface());
	break;
	case overlay:
	// Do nothing since the attachment is done by the handler of
	// `FlutterJNI#createOverlaySurface()` in the native side.
	break;
	}
	setAlpha(1.0f);
	this.flutterRenderer = flutterRenderer;
	isAttachedToFlutterRenderer = true;
	}

	/**
	* Invoked by the owner of this {@code FlutterImageView} when it no longer wants to render a
	* Flutter UI to this {@code FlutterImageView}.
	*/
	public void detachFromRenderer() {
	if (!isAttachedToFlutterRenderer) {
	return;
	}
	setAlpha(0.0f);
	// Drop the latest image as it shouldn't render this image if this view is
	// attached to the renderer again.
	acquireLatestImage();
	// Clear drawings.
	currentBitmap = null;

	// Close and clear the current image if any.
	closeCurrentImage();
	invalidate();
	isAttachedToFlutterRenderer = false;
	}

	public void pause() {
	// Not supported.
	}

	public void resume() {
	// Not supported.
	}

	/**
	* Acquires the next image to be drawn to the {@link android.graphics.Canvas}. Returns true if
	* there's an image available in the queue.
	*/
	public boolean acquireLatestImage() {
	if (!isAttachedToFlutterRenderer) {
	return false;
	}
	// 1. `acquireLatestImage()` may return null if no new image is available.
	// 2. There's no guarantee that `onDraw()` is called after `invalidate()`.
	// For example, the device may not produce new frames if it's in sleep mode
	// or some special Android devices so the calls to `invalidate()` queued up
	// until the device produces a new frame.
	// 3. While the engine will also stop producing frames, there is a race condition.
	final Image newImage = imageReader.acquireLatestImage();
	if (newImage != null) {
	// Only close current image after acquiring valid new image
	closeCurrentImage();
	currentImage = newImage;
	invalidate();
	}
	return newImage != null;
	}

	/** Creates a new image reader with the provided size. */
	public void resizeIfNeeded(int width, int height) {
	if (flutterRenderer == null) {
	return;
	}
	if (width == imageReader.getWidth() && height == imageReader.getHeight()) {
	return;
	}

	// Close resources.
	closeCurrentImage();
	// Close the current image reader, then create a new one with the new size.
	// Image readers cannot be resized once created.
	closeImageReader();
	imageReader = createImageReader(width, height);
	}

	/**
	* Closes the image reader associated with the current {@code FlutterImageView}.
	*
	* <p>Once the image reader is closed, calling {@code acquireLatestImage} will result in an {@code
	* IllegalStateException}.
	*/
	public void closeImageReader() {
	imageReader.close();
	}

	@Override
	protected void onDraw(Canvas canvas) {
	super.onDraw(canvas);
	if (currentImage != null) {
	updateCurrentBitmap();
	}
	if (currentBitmap != null) {
	canvas.drawBitmap(currentBitmap, 0, 0, null);
	}
	}

	private void closeCurrentImage() {
	// Close and clear the current image if any.
	if (currentImage != null) {
	currentImage.close();
	currentImage = null;
	}
	}

	@TargetApi(API_LEVELS.API_29)
	private void updateCurrentBitmap() {
	if (android.os.Build.VERSION.SDK_INT >= API_LEVELS.API_29) {
	final HardwareBuffer buffer = currentImage.getHardwareBuffer();
	currentBitmap = Bitmap.wrapHardwareBuffer(buffer, ColorSpace.get(ColorSpace.Named.SRGB));
	buffer.close();
	} else {
	final Plane[] imagePlanes = currentImage.getPlanes();
	if (imagePlanes.length != 1) {
	return;
	}

	final Plane imagePlane = imagePlanes[0];
	final int desiredWidth = imagePlane.getRowStride() / imagePlane.getPixelStride();
	final int desiredHeight = currentImage.getHeight();

	if (currentBitmap == null
	\|\| currentBitmap.getWidth() != desiredWidth
	\|\| currentBitmap.getHeight() != desiredHeight) {
	currentBitmap =
	Bitmap.createBitmap(
	desiredWidth, desiredHeight, android.graphics.Bitmap.Config.ARGB_8888);
	}
	ByteBuffer buffer = imagePlane.getBuffer();
	buffer.rewind();
	currentBitmap.copyPixelsFromBuffer(buffer);
	}
	}

	@Override
	protected void onSizeChanged(int width, int height, int oldWidth, int oldHeight) {
	if (width == imageReader.getWidth() && height == imageReader.getHeight()) {
	return;
	}
	// `SurfaceKind.overlay` isn't resized. Instead, the `FlutterImageView` instance
	// is destroyed. As a result, an instance with the new size is created by the surface
	// pool in the native side.
	if (kind == SurfaceKind.background && isAttachedToFlutterRenderer) {
	resizeIfNeeded(width, height);
	// Bind native window to the new surface, and create a new onscreen surface
	// with the new size in the native side.
	flutterRenderer.swapSurface(imageReader.getSurface());
	}
	}
	}