java/com/android/dialer/callcomposer/camera/HardwareCameraPreview.java

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.dialer.callcomposer.camera;

import android.content.Context;
import android.graphics.SurfaceTexture;
import android.hardware.Camera;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.view.TextureView;
import android.view.View;
import java.io.IOException;

/**
 * A hardware accelerated preview texture for the camera. This is the preferred CameraPreview
 * because it animates smoother. When hardware acceleration isn't available, SoftwareCameraPreview
 * is used.
 *
 * <p>There is a significant amount of duplication between HardwareCameraPreview and
 * SoftwareCameraPreview which we can't easily share due to a lack of multiple inheritance, The
 * implementations of the shared methods are delegated to CameraPreview
 */
public class HardwareCameraPreview extends TextureView implements CameraPreview.CameraPreviewHost {
  private CameraPreview mPreview;

  public HardwareCameraPreview(final Context context, final AttributeSet attrs) {
    super(context, attrs);
    mPreview = new CameraPreview(this);
    setSurfaceTextureListener(
        new SurfaceTextureListener() {
          @Override
          public void onSurfaceTextureAvailable(
              final SurfaceTexture surfaceTexture, final int i, final int i2) {
            CameraManager.get().setSurface(mPreview);
          }

          @Override
          public void onSurfaceTextureSizeChanged(
              final SurfaceTexture surfaceTexture, final int i, final int i2) {
            CameraManager.get().setSurface(mPreview);
          }

          @Override
          public boolean onSurfaceTextureDestroyed(final SurfaceTexture surfaceTexture) {
            CameraManager.get().setSurface(null);
            return true;
          }

          @Override
          public void onSurfaceTextureUpdated(final SurfaceTexture surfaceTexture) {
            CameraManager.get().setSurface(mPreview);
          }
        });
  }

  @Override
  public void setShown() {
    mPreview.setShown();
  }

  @Override
  protected void onVisibilityChanged(final View changedView, final int visibility) {
    super.onVisibilityChanged(changedView, visibility);
    mPreview.onVisibilityChanged(visibility);
  }

  @Override
  protected void onDetachedFromWindow() {
    super.onDetachedFromWindow();
    mPreview.onDetachedFromWindow();
  }

  @Override
  protected void onAttachedToWindow() {
    super.onAttachedToWindow();
    mPreview.onAttachedToWindow();
  }

  @Override
  protected void onRestoreInstanceState(final Parcelable state) {
    super.onRestoreInstanceState(state);
    mPreview.onRestoreInstanceState();
  }

  @Override
  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    widthMeasureSpec = mPreview.getWidthMeasureSpec(widthMeasureSpec, heightMeasureSpec);
    heightMeasureSpec = mPreview.getHeightMeasureSpec(widthMeasureSpec, heightMeasureSpec);
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
  }

  @Override
  public View getView() {
    return this;
  }

  @Override
  public boolean isValid() {
    return getSurfaceTexture() != null;
  }

  @Override
  public void startPreview(final Camera camera) throws IOException {
    camera.setPreviewTexture(getSurfaceTexture());
  }

  @Override
  public void onCameraPermissionGranted() {
    mPreview.onCameraPermissionGranted();
  }
}