java/com/android/dialer/callcomposer/camera/SoftwareCameraPreview.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.hardware.Camera;
import android.os.Parcelable;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import java.io.IOException;

/**
 * A software rendered preview surface for the camera. This renders slower and causes more jank, so
 * HardwareCameraPreview is preferred if possible.
 *
 * <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 SoftwareCameraPreview extends SurfaceView implements CameraPreview.CameraPreviewHost {
  private final CameraPreview mPreview;

  public SoftwareCameraPreview(final Context context) {
    super(context);
    mPreview = new CameraPreview(this);
    getHolder()
        .addCallback(
            new SurfaceHolder.Callback() {
              @Override
              public void surfaceCreated(final SurfaceHolder surfaceHolder) {
                CameraManager.get().setSurface(mPreview);
              }

              @Override
              public void surfaceChanged(
                  final SurfaceHolder surfaceHolder,
                  final int format,
                  final int width,
                  final int height) {
                CameraManager.get().setSurface(mPreview);
              }

              @Override
              public void surfaceDestroyed(final SurfaceHolder surfaceHolder) {
                CameraManager.get().setSurface(null);
              }
            });
  }

  @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 getHolder() != null;
  }

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

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