android.hardware.Camera#Area ( )源码实例Demo

private static String toString(Iterable<Camera.Area> areas) {
    if (areas == null) {
        return null;
    }
    StringBuilder result = new StringBuilder();
    for (Camera.Area area : areas) {
        result.append(area.rect).append(':').append(area.weight).append(' ');
    }
    return result.toString();
}
 

private static String toString(Iterable<Camera.Area> areas) {
  if (areas == null) {
    return null;
  }
  StringBuilder result = new StringBuilder();
  for (Camera.Area area : areas) {
    result.append(area.rect).append(':').append(area.weight).append(' ');
  }
  return result.toString();
}
 

private static String toString(Iterable<Camera.Area> areas) {
  if (areas == null) {
    return null;
  }
  StringBuilder result = new StringBuilder();
  for (Camera.Area area : areas) {
    result.append(area.rect).append(':').append(area.weight).append(' ');
  }
  return result.toString();
}
 

public static void setFocusArea(Camera.Parameters parameters) {
  if (parameters.getMaxNumFocusAreas() > 0) {
    Log.i(TAG, "Old focus areas: " + toString(parameters.getFocusAreas()));
    List<Camera.Area> middleArea = buildMiddleArea(AREA_PER_1000);
    Log.i(TAG, "Setting focus area to : " + toString(middleArea));
    parameters.setFocusAreas(middleArea);
  } else {
    Log.i(TAG, "Device does not support focus areas");
  }
}
 

public static void setFocusArea(Camera.Parameters parameters) {
    if (parameters.getMaxNumFocusAreas() > 0) {
        Log.i(TAG, "Old focus areas: " + toString(parameters.getFocusAreas()));
        List<Camera.Area> middleArea = buildMiddleArea(AREA_PER_1000);
        Log.i(TAG, "Setting focus area to : " + toString(middleArea));
        parameters.setFocusAreas(middleArea);
    } else {
        Log.i(TAG, "Device does not support focus areas");
    }
}
 

public static void setMetering(Camera.Parameters parameters) {
    if (parameters.getMaxNumMeteringAreas() > 0) {
        Log.i(TAG, "Old metering areas: " + parameters.getMeteringAreas());
        List<Camera.Area> middleArea = buildMiddleArea(AREA_PER_1000);
        Log.i(TAG, "Setting metering area to : " + toString(middleArea));
        parameters.setMeteringAreas(middleArea);
    } else {
        Log.i(TAG, "Device does not support metering areas");
    }
}
 

private static Point convertCameraPointToActiveArrayPoint(
        Rect activeArray, ZoomData zoomData, Point point, boolean usePreviewCrop) {
    Rect pointedRect = new Rect(point.x, point.y, point.x, point.y);
    Camera.Area pointedArea = new Area(pointedRect, /*weight*/1);

    WeightedRectangle adjustedRect =
            convertCameraAreaToActiveArrayRectangle(activeArray,
                    zoomData, pointedArea, usePreviewCrop);

    Point transformedPoint = new Point(adjustedRect.rect.left, adjustedRect.rect.top);

    return transformedPoint;
}
 

public static void setMetering(Camera.Parameters parameters) {
  if (parameters.getMaxNumMeteringAreas() > 0) {
    Log.i(TAG, "Old metering areas: " + parameters.getMeteringAreas());
    List<Camera.Area> middleArea = buildMiddleArea(AREA_PER_1000);
    Log.i(TAG, "Setting metering area to : " + toString(middleArea));
    parameters.setMeteringAreas(middleArea);
  } else {
    Log.i(TAG, "Device does not support metering areas");
  }
}
 

public boolean manualFocus(Camera camera, Camera.AutoFocusCallback cb, List<Camera.Area> focusAreas
        ,List<Camera.Area> mFocusAreas) {
    //判断系统是否是4.0以上的版本
    if (camera != null && focusAreas != null && SystemVersionUtil.hasICS()) {
        try {
            camera.cancelAutoFocus();
            Camera.Parameters parameters = camera.getParameters();
            if(parameters != null){
                // getMaxNumFocusAreas检测设备是否支持
                if (parameters.getMaxNumFocusAreas() > 0) {
                    parameters.setFocusAreas(focusAreas);
                }
                // getMaxNumMeteringAreas检测设备是否支持
                if (parameters.getMaxNumMeteringAreas() > 0)
                    parameters.setMeteringAreas(mFocusAreas);
                parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_MACRO);
                camera.setParameters(parameters);
                camera.autoFocus(cb);
                return true;
            }
        } catch (Exception e) {
            if (e != null)
                Log.e(" ", "autoFocus", e);
        }
    }
    return false;
}
 

public Observable<RxCamera> areaFocusAction(final List<Camera.Area> focusAreaList) {
    if (focusAreaList == null || focusAreaList.size() == 0) {
        return null;
    }
    return Observable.create(new Observable.OnSubscribe<RxCamera>() {
        @Override
        public void call(final Subscriber<? super RxCamera> subscriber) {
            Camera.Parameters parameters = rxCamera.getNativeCamera().getParameters();
            if (parameters.getMaxNumFocusAreas() < focusAreaList.size()) {
                subscriber.onError(new SettingAreaFocusError(SettingAreaFocusError.Reason.NOT_SUPPORT));
            } else {
                if (parameters.getFocusMode() != Camera.Parameters.FOCUS_MODE_AUTO) {
                    List<String> focusModes = parameters.getSupportedFocusModes();
                    if (focusModes.contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
                        parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
                    }
                }
                parameters.setFocusAreas(focusAreaList);
                rxCamera.getNativeCamera().setParameters(parameters);
                rxCamera.getNativeCamera().autoFocus(new Camera.AutoFocusCallback() {
                    @Override
                    public void onAutoFocus(boolean success, Camera camera) {
                        if (success) {
                            subscriber.onNext(rxCamera);
                        } else {
                            subscriber.onError(new SettingAreaFocusError(SettingAreaFocusError.Reason.SET_AREA_FOCUS_FAILED));
                        }
                    }
                });
            }
        }
    });
}
 

public static void setFocusArea(Camera.Parameters parameters) {
  if (parameters.getMaxNumFocusAreas() > 0) {
    Log.i(TAG, "Old focus areas: " + toString(parameters.getFocusAreas()));
    List<Camera.Area> middleArea = buildMiddleArea(AREA_PER_1000);
    Log.i(TAG, "Setting focus area to : " + toString(middleArea));
    parameters.setFocusAreas(middleArea);
  } else {
    Log.i(TAG, "Device does not support focus areas");
  }
}
 

public static void setMetering(Camera.Parameters parameters) {
    if (parameters.getMaxNumMeteringAreas() > 0) {
        Log.i(TAG, "Old metering areas: " + parameters.getMeteringAreas());
        List<Camera.Area> middleArea = buildMiddleArea(AREA_PER_1000);
        Log.i(TAG, "Setting metering area to : " + toString(middleArea));
        parameters.setMeteringAreas(middleArea);
    } else {
        Log.i(TAG, "Device does not support metering areas");
    }
}
 

public void focusOnPoint(int x, int y, int width, int height) {
    Log.v(TAG, "touch point (" + x + ", " + y + ")");
    if (mCamera == null) {
        return;
    }
    Parameters parameters = mCamera.getParameters();
    // 1.先要判断是否支持设置聚焦区域
    if (parameters.getMaxNumFocusAreas() > 0) {
        // 2.以触摸点为中心点，view窄边的1/4为聚焦区域的默认边长
        int length = Math.min(width, height) >> 3; // 1/8的长度
        int left = x - length;
        int top = y - length;
        int right = x + length;
        int bottom = y + length;
        // 3.映射，因为相机聚焦的区域是一个(-1000,-1000)到(1000,1000)的坐标区域
        left = left * 2000 / width - 1000;
        top = top * 2000 / height - 1000;
        right = right * 2000 / width - 1000;
        bottom = bottom * 2000 / height - 1000;
        // 4.判断上述矩形区域是否超过边界，若超过则设置为临界值
        left = left < -1000 ? -1000 : left;
        top = top < -1000 ? -1000 : top;
        right = right > 1000 ? 1000 : right;
        bottom = bottom > 1000 ? 1000 : bottom;
        Log.d(TAG, "focus area (" + left + ", " + top + ", " + right + ", " + bottom + ")");
        ArrayList<Camera.Area> areas = new ArrayList<>();
        areas.add(new Camera.Area(new Rect(left, top, right, bottom), 600));
        parameters.setFocusAreas(areas);
    }
    try {
        mCamera.cancelAutoFocus(); // 先要取消掉进程中所有的聚焦功能
        mCamera.setParameters(parameters);
        mCamera.autoFocus(this); // 调用聚焦
    } catch (Exception e) {
        e.printStackTrace();
    }
}
 

public static void setFocusArea(Camera.Parameters parameters) {
  if (parameters.getMaxNumFocusAreas() > 0) {
    Log.i(TAG, "Old focus areas: " + toString(parameters.getFocusAreas()));
    List<Camera.Area> middleArea = buildMiddleArea(AREA_PER_1000);
    Log.i(TAG, "Setting focus area to : " + toString(middleArea));
    parameters.setFocusAreas(middleArea);
  } else {
    Log.i(TAG, "Device does not support focus areas");
  }
}
 

public static void setMetering(Camera.Parameters parameters) {
  if (parameters.getMaxNumMeteringAreas() > 0) {
    Log.i(TAG, "Old metering areas: " + parameters.getMeteringAreas());
    List<Camera.Area> middleArea = buildMiddleArea(AREA_PER_1000);
    Log.i(TAG, "Setting metering area to : " + toString(middleArea));
    parameters.setMeteringAreas(middleArea);
  } else {
    Log.i(TAG, "Device does not support metering areas");
  }
}
 

@TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1)
private static List<Camera.Area> buildMiddleArea(int areaPer1000) {
    return Collections.singletonList(
            new Camera.Area(new Rect(-areaPer1000, -areaPer1000, areaPer1000, areaPer1000), 1));
}
 

private static List<Camera.Area> buildMiddleArea(int areaPer1000) {
  return Collections.singletonList(
      new Camera.Area(new Rect(-areaPer1000, -areaPer1000, areaPer1000, areaPer1000), 1));
}
 

private static List<Camera.Area> buildMiddleArea(int areaPer1000) {
  return Collections.singletonList(
      new Camera.Area(new Rect(-areaPer1000, -areaPer1000, areaPer1000, areaPer1000), 1));
}
 

/**
 * @param areas The areas for autoexposure. The coordinate system has domain
 *              and range [-1000,1000], measured relative to the visible
 *              preview image, with orientation matching that of the sensor.
 *              This means the coordinates must be transformed to account
 *              for the devices rotation---but not the zoom level---before
 *              being passed into this method.
 */
public void setMeteringAreas(List<Camera.Area> areas) {
    mMeteringAreas.clear();
    if (areas != null) {
        mMeteringAreas.addAll(areas);
    }
}
 

/**
 * Convert the normalized camera area from [-1000, 1000] coordinate space
 * into the active array-based coordinate space.
 *
 * <p>Values out of range are clipped to be within the resulting (reported) crop
 * region. It is possible to have values larger than the preview crop.</p>
 *
 * <p>Weights out of range of [0, 1000] are clipped to be within the range.</p>
 *
 * @param activeArraySize active array size of the sensor (e.g. max jpeg size)
 * @param zoomData the calculated zoom data corresponding to this request
 * @param area the normalized camera area
 *
 * @return the weighed rectangle in active array coordinate space, with the weight
 */
public static WeightedRectangle convertCameraAreaToActiveArrayRectangle(
        Rect activeArray, ZoomData zoomData, Camera.Area area) {
    return convertCameraAreaToActiveArrayRectangle(activeArray, zoomData, area,
            /*usePreviewCrop*/true);
}