package com.example.cameraaperture;import android.content.Context;import android.content.res.TypedArray;import android.graphics.Bitmap;import android.graphics.Bitmap.Config;import android.graphics.Canvas;import android.graphics.Paint;import android.graphics.Path;import android.graphics.PointF;import android.util.AttributeSet;import android.util.Log;import android.view.MotionEvent;import android.view.View;/** * 上下滑動可以調節光圈大小； * 調用setApertureChangedListener設置光圈值變動監聽接口； * 繪制的光圈最大直徑將填滿整個view * @author willhua http://www.cnblogs.com/willhua/ *  */public class ApertureView extends View {  public interface ApertureChanged {    public void onApertureChanged(float newapert);  }  private static final float ROTATE_ANGLE = 30;  private static final String TAG = "ApertureView";  private static final float COS_30 = 0.866025f;  private static final int WIDTH = 100; // 當設置為wrap_content時測量大小  private static final int HEIGHT = 100;  private int mCircleRadius;  private int mBladeColor;  private int mBackgroundColor;  private int mSpace;  private float mMaxApert = 1;  private float mMinApert = 0.2f;  private float mCurrentApert = 0.5f;  //利用PointF而不是Point可以減少計算誤差，以免葉片之間間隔由于計算誤差而不均衡  private PointF[] mPoints = new PointF[6];   private Bitmap mBlade;  private Paint mPaint;  private Path mPath;  private ApertureChanged mApertureChanged;  private float mPrevX;  private float mPrevY;  public ApertureView(Context context, AttributeSet attrs) {    super(context, attrs);    init(context, attrs);  }  private void init(Context context, AttributeSet attrs) {    //讀取自定義布局屬性    TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.ApertureView);    mSpace = (int)array.getDimension(R.styleable.ApertureView_blade_space, 5);    mBladeColor = array.getColor(R.styleable.ApertureView_blade_color, 0xFF000000);    mBackgroundColor = array.getColor(R.styleable.ApertureView_background_color, 0xFFFFFFFF);    array.recycle();    mPaint = new Paint(Paint.FILTER_BITMAP_FLAG | Paint.DITHER_FLAG);    mPaint.setAntiAlias(true);    for (int i = 0; i < 6; i++) {      mPoints[i] = new PointF();    }  }  @Override  protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {    super.onMeasure(widthMeasureSpec, heightMeasureSpec);    int widthSpecMode = MeasureSpec.getMode(widthMeasureSpec);    int heightSpecMode = MeasureSpec.getMode(heightMeasureSpec);    int widthSpecSize = MeasureSpec.getSize(widthMeasureSpec);    int heightSpecSize = MeasureSpec.getSize(heightMeasureSpec);    int paddX = getPaddingLeft() + getPaddingRight();    int paddY = getPaddingTop() + getPaddingBottom();    //光圈的大小要考慮減去view的padding值    mCircleRadius = widthSpecSize - paddX < heightSpecSize - paddY ? (widthSpecSize - paddX) / 2        : (heightSpecSize - paddY) / 2;    //對布局參數為wrap_content時的處理    if (widthSpecMode == MeasureSpec.AT_MOST        && heightSpecMode == MeasureSpec.AT_MOST) {      setMeasuredDimension(WIDTH, HEIGHT);      mCircleRadius = (WIDTH - paddX) / 2;    } else if (widthSpecMode == MeasureSpec.AT_MOST) {      setMeasuredDimension(WIDTH, heightSpecSize);      mCircleRadius = WIDTH - paddX < heightSpecSize - paddY ? (WIDTH - paddX) / 2          : (heightSpecSize - paddY) / 2;    } else if (heightSpecMode == MeasureSpec.AT_MOST) {      setMeasuredDimension(widthSpecSize, HEIGHT);      mCircleRadius = widthSpecSize - paddX < HEIGHT - paddY ? (widthSpecSize - paddX) / 2          : (HEIGHT - paddY) / 2;    }    if (mCircleRadius < 1) {      mCircleRadius = 1;    }    //measure之后才能知道所需要繪制的光圈大小    mPath = new Path();    mPath.addCircle(0, 0, mCircleRadius, Path.Direction.CW);    createBlade();  }  @Override  public void onDraw(Canvas canvas) {    canvas.save();    calculatePoints();    //先把canbvas平移到view的中間    canvas.translate(getWidth() / 2, getHeight() / 2);    //讓光圈的葉片整體旋轉，更加貼合實際    canvas.rotate(ROTATE_ANGLE * (mCurrentApert - mMinApert) / (mMaxApert - mMinApert));    canvas.clipPath(mPath);    canvas.drawColor(mBackgroundColor);    for (int i = 0; i < 6; i++) {      canvas.save();      canvas.translate(mPoints[i].x, mPoints[i].y);      canvas.rotate(-i * 60);      canvas.drawBitmap(mBlade, 0, 0, mPaint);      canvas.restore();    }    canvas.restore();  }  @Override  public boolean onTouchEvent(MotionEvent event) {    if (event.getPointerCount() > 1) {      return false;    }    switch (event.getAction()) {    case MotionEvent.ACTION_DOWN:      mPrevX = event.getX();      mPrevY = event.getY();      break;    case MotionEvent.ACTION_MOVE:      float diffx = Math.abs((event.getX() - mPrevX));      float diffy = Math.abs((event.getY() - mPrevY));      if (diffy > diffx) { // 豎直方向的滑動        float diff = (float) Math.sqrt(diffx * diffx + diffy * diffy)            / mCircleRadius * mMaxApert;        if (event.getY() > mPrevY) { //判斷方向          setCurrentApert(mCurrentApert - diff);        } else {          setCurrentApert(mCurrentApert + diff);        }        mPrevX = event.getX();        mPrevY = event.getY();      }      break;    default:      break;    }    return true;  }  private void calculatePoints() {    if (mCircleRadius - mSpace <= 0) {      Log.e(TAG, "the size of view is too small and Space is too large");      return;    }    //mCircleRadius - mSpace可以保證內嵌六邊形在光圈內    float curRadius = mCurrentApert / mMaxApert * (mCircleRadius - mSpace);    //利用對稱關系，減少計算    mPoints[0].x = curRadius / 2;    mPoints[0].y = -curRadius * COS_30;    mPoints[1].x = -mPoints[0].x;    mPoints[1].y = mPoints[0].y;    mPoints[2].x = -curRadius;    mPoints[2].y = 0;    mPoints[3].x = mPoints[1].x;    mPoints[3].y = -mPoints[1].y;    mPoints[4].x = -mPoints[3].x;    mPoints[4].y = mPoints[3].y;    mPoints[5].x = curRadius;    mPoints[5].y = 0;  }  //創建光圈葉片，讓美工MM提供更好  private void createBlade() {    mBlade = Bitmap.createBitmap(mCircleRadius,        (int) (mCircleRadius * 2 * COS_30), Config.ARGB_8888);    Path path = new Path();    Canvas canvas = new Canvas(mBlade);    path.moveTo(mSpace / 2 / COS_30, mSpace);    path.lineTo(mBlade.getWidth(), mBlade.getHeight());    path.lineTo(mBlade.getWidth(), mSpace);    path.close();    canvas.clipPath(path);    canvas.drawColor(mBladeColor);  }  /**   * 設置光圈片的顏色   * @param bladeColor   */  public void setBladeColor(int bladeColor) {    mBladeColor = bladeColor;  }  /**   * 設置光圈背景色   */  public void setBackgroundColor(int backgroundColor) {    mBackgroundColor = backgroundColor;  }  /**   * 設置光圈片之間的間隔   * @param space   */  public void setSpace(int space) {    mSpace = space;  }  /**   * 設置光圈最大值   * @param maxApert   */  public void setMaxApert(float maxApert) {    mMaxApert = maxApert;  }  /**   * 設置光圈最小值   * @param mMinApert   */  public void setMinApert(float mMinApert) {    this.mMinApert = mMinApert;  }  public float getCurrentApert() {    return mCurrentApert;  }  public void setCurrentApert(float currentApert) {    if (currentApert > mMaxApert) {      currentApert = mMaxApert;    }    if (currentApert < mMinApert) {      currentApert = mMinApert;    }    if (mCurrentApert == currentApert) {      return;    }    mCurrentApert = currentApert;    invalidate();    if (mApertureChanged != null) {      mApertureChanged.onApertureChanged(currentApert);    }  }  /**   * 設置光圈值變動的監聽   * @param listener   */  public void setApertureChangedListener(ApertureChanged listener) {    mApertureChanged = listener;  }}

<?xml version="1.0" encoding="utf-8"?><resources>  <declare-styleable name="ApertureView">    <attr name="blade_color" format="color" />    <attr name="background_color" format="color" />    <attr name="blade_space" format="dimension" />  </declare-styleable></resources>