Android自定义view实现图片选色器

allprojects {
  repositories {
   ...
   maven { url "https://jitpack.io" }
  }
 }

dependencies {
   compile 'com.github.autume:ColorPickerView:1.0'
 }

<RelativeLayout
  android:id="@+id/rl_picker"
  android:layout_below="@+id/img_color"
  android:layout_marginTop="30dp"
  android:layout_centerHorizontal="true"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content">

  <colorpickerview.oden.com.colorpicker.ColorPickerView
   android:id="@+id/color_picker"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"/>


  <ImageView
   android:id="@+id/img_picker"
   android:layout_centerInParent="true"
   android:src="@mipmap/color_picker"
   android:layout_width="25dp"
   android:layout_height="25dp" />

 </RelativeLayout>

private void initRgbPicker() {
  colorPickerView = (ColorPickerView) findViewById(R.id.color_picker);
  colorPickerView.setImgPicker(MainActivity.this, img_picker, 25); //最后一个参数是该颜色指示圈的大小(dp)
  colorPickerView.setColorChangedListener(new ColorPickerView.onColorChangedListener() {
   @Override
   public void colorChanged(int red, int blue, int green) {
    img_color.setColorFilter(Color.argb(255, red, green, blue));
   }

   @Override
   public void stopColorChanged(int red, int blue, int green) {

   }
  });
 }

 public void setImgPicker(final Context context, final ImageView imgPicker, final int pickerViewWidth)
 public void setImgResource(final int imgResource)
 public void setColorChangedListener(onColorChangedListener colorChangedListener)

 <declare-styleable name="ColorPickerView">
  <attr name="picture_resource" format="reference"/>
 </declare-styleable>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:id="@+id/rl_root"
 tools:background="@color/black"
 android:layout_width="match_parent"
 android:layout_height="wrap_content">

 <ImageView
  android:id="@+id/img_color_rang"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_centerInParent="true"
  android:src="@mipmap/lights_colors" />


</RelativeLayout>

private void initAttrs(Context context, AttributeSet attrs) {
  if (null != attrs) {
   TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.ColorPickerView);
   imgResource = typedArray.getResourceId(R.styleable.ColorPickerView_picture_resource, 0);
   typedArray.recycle();
  }
 }

 private void initView(Context context) {
  View view = LayoutInflater.from(context).inflate(R.layout.color_picker, this);
  imgColorRang = (ImageView) view.findViewById(R.id.img_color_rang);
  rl_root = (RelativeLayout) view.findViewById(R.id.rl_root);

  if (imgResource != 0)
   imgColorRang.setImageResource(imgResource);

  bitmap = ((BitmapDrawable) imgColorRang.getDrawable()).getBitmap();//获取圆盘图片
 }

 private onColorChangedListener colorChangedListener;//颜色变换监听

 public void setColorChangedListener(onColorChangedListener colorChangedListener) {
  this.colorChangedListener = colorChangedListener;
 }

 /**
  * 颜色变换监听接口
  */
 public interface onColorChangedListener {
  void colorChanged(int red, int blue, int green);
  void stopColorChanged(int red, int blue, int green);
 }

 private void initTouchListener() {
  rl_root.setOnTouchListener(new OnTouchListener() {
   @Override
   public boolean onTouch(View v, MotionEvent event) {

    if (range_radius == 0) {
     range_radius = imgColorRang.getWidth() / 2; //圆盘半径
     centreX = imgColorRang.getRight() - range_radius;
     centreY = imgColorRang.getBottom() - imgColorRang.getHeight() / 2;
     select_radius = range_radius - pickerViewPadding/5;
    }

    float xInView = event.getX();
    float yInView = event.getY();
    Log.d(TAG, "xInView: " + xInView + ",yInView: " + yInView + ",left: " + imgColorRang.getLeft() + ",top: " + imgColorRang.getTop() + ",right: " +imgColorRang.getRight() + ",bottom: " + imgColorRang.getBottom());

    //触摸点与圆盘圆心距离
    float diff = (float) Math.sqrt((centreY - yInView) * (centreY - yInView) + (centreX - xInView) *
      (centreX - xInView));

    //在选色图片内则进行读取颜色等操作
    if (diff <= select_radius) {

     //选色位置指示，若设置了则移动到点取的位置
     if (imgPicker != null ) {
      int xInWindow = (int) event.getX();
      int yInWindow = (int) event.getY();
      int left = xInWindow + v.getLeft() - imgPicker.getWidth() / 2;
      int top = yInWindow + v.getTop() - imgPicker.getWidth() / 2;
      int right = left + imgPicker.getWidth();
      int bottom = top + imgPicker.getHeight();

      imgPicker.layout(left, top, right, bottom);
     }


     if ((event.getY() - imgColorRang.getTop()) < 0)
      return true;
     //读取颜色
     int pixel = bitmap.getPixel((int) (event.getX() - imgColorRang.getLeft()), (int) (event.getY() - imgColorRang.getTop())); //获取选择像素
     if (colorChangedListener != null) {
      if (event.getAction() == MotionEvent.ACTION_UP) {
       colorChangedListener.stopColorChanged(Color.red(pixel), Color.blue(pixel), Color.green(pixel));
      }else {
       colorChangedListener.colorChanged(Color.red(pixel), Color.blue(pixel), Color.green(pixel));
      }
     }
     Log.d(TAG, "radValue=" + Color.red(pixel) + " blueValue=" + Color.blue(pixel) + " greenValue" + Color.green(pixel));
    }
    return true;
   }
  });
 }

public void setImgPicker(final Context context, final ImageView imgPicker, final int pickerViewWidth) {
  this.imgPicker = imgPicker;
  pickerViewPadding = dip2px(context, pickerViewWidth/2);
  new Handler().postDelayed(new Runnable() {
   @Override
   public void run() {
    rl_root.setPadding(pickerViewPadding, pickerViewPadding, pickerViewPadding, pickerViewPadding);
    bitmap = ((BitmapDrawable) imgColorRang.getDrawable()).getBitmap();//获取圆盘图片
   }
  },10);
 }