Android双向选择控件DoubleSeekBar使用详解

public class DoubleSlideSeekBar extends View {
 /**
 * 线条（进度条）的宽度
 */
 private int lineWidth;
 /**
 * 线条（进度条）的长度
 */
 private int lineLength = 400;
 /**
 * 字所在的高度 100$
 */
 private int textHeight;
 /**
 * 游标 图片宽度
 */
 private int imageWidth;
 /**
 * 游标 图片高度
 */
 private int imageHeight;
 /**
 * 是否有刻度线
 */
 private boolean hasRule;
 /**
 * 左边的游标是否在动
 */
 private boolean isLowerMoving;
 /**
 * 右边的游标是否在动
 */
 private boolean isUpperMoving;
 /**
 * 字的大小 100$
 */
 private int textSize;
 /**
 * 字的颜色 100$
 */
 private int textColor;
 /**
 * 两个游标内部 线（进度条）的颜色
 */
 private int inColor = Color.BLUE;
 /**
 * 两个游标外部 线（进度条）的颜色
 */
 private int outColor = Color.BLUE;
 /**
 * 刻度的颜色
 */
 private int ruleColor = Color.BLUE;
 /**
 * 刻度上边的字 的颜色
 */
 private int ruleTextColor = Color.BLUE;
 /**
 * 左边图标的图片
 */
 private Bitmap bitmapLow;
 /**
 * 右边图标 的图片
 */
 private Bitmap bitmapBig;
 /**
 * 左边图标所在X轴的位置
 */
 private int slideLowX;
 /**
 * 右边图标所在X轴的位置
 */
 private int slideBigX;
 /**
 * 图标（游标） 高度
 */
 private int bitmapHeight;
 /**
 * 图标（游标） 宽度
 */
 private int bitmapWidth;
 /**
 * 加一些padding 大小酌情考虑 为了我们的自定义view可以显示完整
 */
 private int paddingLeft = 100;
 private int paddingRight = 100;
 private int paddingTop = 50;
 private int paddingBottom = 10;
 /**
 * 线（进度条） 开始的位置
 */
 private int lineStart = paddingLeft;
 /**
 * 线的Y轴位置
 */
 private int lineY;
 /**
 * 线（进度条）的结束位置
 */
 private int lineEnd = lineLength + paddingLeft;
 /**
 * 选择器的最大值
 */
 private int bigValue = 100;
 /**
 * 选择器的最小值
 */
 private int smallValue = 0;
 /**
 * 选择器的当前最小值
 */
 private float smallRange;
 /**
 * 选择器的当前最大值
 */
 private float bigRange;
 /**
 * 单位 元
 */
 private String unit = " ";
 /**
 * 单位份数
 */
 private int equal = 20;
 /**
 * 刻度单位 $
 */
 private String ruleUnit = " ";
 /**
 * 刻度上边文字的size
 */
 private int ruleTextSize = 20;
 /**
 * 刻度线的高度
 */
 private int ruleLineHeight = 20;
 private Paint linePaint;
 private Paint bitmapPaint;
 private Paint textPaint;
 private Paint paintRule;
 public DoubleSlideSeekBar(Context context) {
 this(context, null);
 }
 public DoubleSlideSeekBar(Context context, @Nullable AttributeSet attrs) {
 this(context, attrs, 0);
 }
 public DoubleSlideSeekBar(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);
 TypedArray typedArray = context.getTheme().obtainStyledAttributes(attrs, R.styleable.DoubleSlideSeekBar, defStyleAttr, 0);
 int size = typedArray.getIndexCount();
 for (int i = 0; i < size; i++) {
  int type = typedArray.getIndex(i);
  switch (type) {
  case R.styleable.DoubleSlideSeekBar_inColor:
   inColor = typedArray.getColor(type, Color.BLACK);
   break;
  case R.styleable.DoubleSlideSeekBar_lineHeight:
   lineWidth = (int) typedArray.getDimension(type, dip2px(getContext(), 10));
   break;
  case R.styleable.DoubleSlideSeekBar_outColor:
   outColor = typedArray.getColor(type, Color.YELLOW);
   break;
  case R.styleable.DoubleSlideSeekBar_textColor:
   textColor = typedArray.getColor(type, Color.BLUE);
   break;
  case R.styleable.DoubleSlideSeekBar_textSize:
   textSize = typedArray.getDimensionPixelSize(type, (int) TypedValue.applyDimension(
    TypedValue.COMPLEX_UNIT_SP, 16, getResources().getDisplayMetrics()));
   break;
  case R.styleable.DoubleSlideSeekBar_imageLow:
   bitmapLow = BitmapFactory.decodeResource(getResources(), typedArray.getResourceId(type, 0));
   break;
  case R.styleable.DoubleSlideSeekBar_imageBig:
   bitmapBig = BitmapFactory.decodeResource(getResources(), typedArray.getResourceId(type, 0));
   break;
  case R.styleable.DoubleSlideSeekBar_imageheight:
   imageHeight = (int) typedArray.getDimension(type, dip2px(getContext(), 20));
   break;
  case R.styleable.DoubleSlideSeekBar_imagewidth:
   imageWidth = (int) typedArray.getDimension(type, dip2px(getContext(), 20));
   break;
  case R.styleable.DoubleSlideSeekBar_hasRule:
   hasRule = typedArray.getBoolean(type, false);
   break;
  case R.styleable.DoubleSlideSeekBar_ruleColor:
   ruleColor = typedArray.getColor(type, Color.BLUE);
   break;
  case R.styleable.DoubleSlideSeekBar_ruleTextColor:
   ruleTextColor = typedArray.getColor(type, Color.BLUE);
   break;
  case R.styleable.DoubleSlideSeekBar_unit:
   unit = typedArray.getString(type);
   break;
  case R.styleable.DoubleSlideSeekBar_equal:
   equal = typedArray.getInt(type, 10);
   break;
  case R.styleable.DoubleSlideSeekBar_ruleUnit:
   ruleUnit = typedArray.getString(type);
   break;
  case R.styleable.DoubleSlideSeekBar_ruleTextSize:
   ruleTextSize = typedArray.getDimensionPixelSize(type, (int) TypedValue.applyDimension(
    TypedValue.COMPLEX_UNIT_SP, 16, getResources().getDisplayMetrics()));
   break;
  case R.styleable.DoubleSlideSeekBar_ruleLineHeight:
   ruleLineHeight = (int) typedArray.getDimension(type, dip2px(getContext(), 10));
   break;
  case R.styleable.DoubleSlideSeekBar_bigValue:
   bigValue = typedArray.getInteger(type, 100);
   break;
  case R.styleable.DoubleSlideSeekBar_smallValue:
   smallValue = typedArray.getInteger(type, 100);
   break;
  default:
   break;
  }
 }
 typedArray.recycle();
 init();
 }
 private void init() {
 /**游标的默认图*/
 if (bitmapLow == null) {
  bitmapLow = BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher);
 }
 if (bitmapBig == null) {
  bitmapBig = BitmapFactory.decodeResource(getResources(), R.mipmap.ic_launcher);
 }
 /**游标图片的真实高度 之后通过缩放比例可以把图片设置成想要的大小*/
 bitmapHeight = bitmapLow.getHeight();
 bitmapWidth = bitmapLow.getWidth();
 // 设置想要的大小
 int newWidth = imageWidth;
 int newHeight = imageHeight;
 // 计算缩放比例
 float scaleWidth = ((float) newWidth) / bitmapWidth;
 float scaleHeight = ((float) newHeight) / bitmapHeight;
 Matrix matrix = new Matrix();
 matrix.postScale(scaleWidth, scaleHeight);
 /**缩放图片*/
 bitmapLow = Bitmap.createBitmap(bitmapLow, 0, 0, bitmapWidth, bitmapHeight, matrix, true);
 bitmapBig = Bitmap.createBitmap(bitmapBig, 0, 0, bitmapWidth, bitmapHeight, matrix, true);
 /**重新获取游标图片的宽高*/
 bitmapHeight = bitmapLow.getHeight();
 bitmapWidth = bitmapLow.getWidth();
 /**初始化两个游标的位置*/
 slideLowX = lineStart;
 slideBigX = lineEnd;
 smallRange = smallValue;
 bigRange = bigValue;
 if (hasRule) {
  //有刻度时 paddingTop 要加上（text高度）和（刻度线高度加刻度线上边文字的高度和） 之间的最大值
  paddingTop = paddingTop + Math.max(textSize, ruleLineHeight + ruleTextSize);
 } else {
  //没有刻度时 paddingTop 加上 text的高度
  paddingTop = paddingTop + textSize;
 }
 }
 @Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
 int width = getMyMeasureWidth(widthMeasureSpec);
 int height = getMyMeasureHeight(heightMeasureSpec);
 setMeasuredDimension(width, height);
 }
 private int getMyMeasureHeight(int heightMeasureSpec) {
 int mode = MeasureSpec.getMode(heightMeasureSpec);
 int size = MeasureSpec.getSize(heightMeasureSpec);
 if (mode == MeasureSpec.EXACTLY) {
  // matchparent 或者 固定大小 view最小应为 paddingBottom + paddingTop + bitmapHeight + 10 否则显示不全
  size = Math.max(size, paddingBottom + paddingTop + bitmapHeight + 10);
 } else {
  //wrap content
  int height = paddingBottom + paddingTop + bitmapHeight + 10;
  size = Math.min(size, height);
 }
 return size;
 }
 private int getMyMeasureWidth(int widthMeasureSpec) {
 int mode = MeasureSpec.getMode(widthMeasureSpec);
 int size = MeasureSpec.getSize(widthMeasureSpec);
 if (mode == MeasureSpec.EXACTLY) {
  size = Math.max(size, paddingLeft + paddingRight + bitmapWidth * 2);
 } else {
  //wrap content
  int width = paddingLeft + paddingRight + bitmapWidth * 2;
  size = Math.min(size, width);
 }
 // match parent 或者 固定大小 此时可以获取线（进度条）的长度
 lineLength = size - paddingLeft - paddingRight - bitmapWidth;
 //线（进度条）的结束位置
 lineEnd = lineLength + paddingLeft + bitmapWidth / 2;
 //线（进度条）的开始位置
 lineStart = paddingLeft + bitmapWidth / 2;
 //初始化 游标位置
 slideBigX = lineEnd;
 slideLowX = lineStart;
 return size;
 }
 @Override
 protected void onDraw(Canvas canvas) {
 super.onDraw(canvas);
 // Y轴 坐标
 lineY = getHeight() - paddingBottom - bitmapHeight / 2;
 // 字所在高度 100$
 textHeight = lineY - bitmapHeight / 2 - 10;
// //是否画刻度
// if (hasRule) {
//  drawRule(canvas);
// }
// if (linePaint == null) {
//  linePaint = new Paint();
// }
 linePaint = new Paint();
 //画内部线
 linePaint.setAntiAlias(true);
 linePaint.setStrokeWidth(lineWidth);
 linePaint.setColor(inColor);
 linePaint.setStrokeCap(Paint.Cap.ROUND);
 canvas.drawLine(slideLowX, lineY, slideBigX, lineY, linePaint);
 linePaint.setColor(outColor);
 linePaint.setStrokeCap(Paint.Cap.ROUND);
 //画 外部线
 canvas.drawLine(lineStart, lineY, slideLowX, lineY, linePaint);
 canvas.drawLine(slideBigX, lineY, lineEnd, lineY, linePaint);
 //画游标
 if (bitmapPaint == null) {
  bitmapPaint = new Paint();
 }
 canvas.drawBitmap(bitmapLow, slideLowX - bitmapWidth / 2, lineY - bitmapHeight / 2, bitmapPaint);
 canvas.drawBitmap(bitmapBig, slideBigX - bitmapWidth / 2, lineY - bitmapHeight / 2, bitmapPaint);
 //画 游标上边的字
 if (textPaint == null) {
  textPaint = new Paint();
 }
 textPaint.setColor(textColor);
 textPaint.setTextSize(textSize);
 textPaint.setAntiAlias(true);
 canvas.drawText(String.format("%.0f" + unit, smallRange), slideLowX - bitmapWidth / 2, textHeight, textPaint);
 canvas.drawText(String.format("%.0f" + unit, bigRange), slideBigX - bitmapWidth / 2, textHeight, textPaint);
 }
 @Override
 public boolean onTouchEvent(MotionEvent event) {
 //事件机制
 super.onTouchEvent(event);
 float nowX = event.getX();
 float nowY = event.getY();
 switch (event.getAction()) {
  case MotionEvent.ACTION_DOWN:
  //按下 在线（进度条）范围上
  boolean rightY = Math.abs(nowY - lineY) < bitmapHeight / 2;
  //按下 在左边游标上
  boolean lowSlide = Math.abs(nowX - slideLowX) < bitmapWidth / 2;
  //按下 在右边游标上
  boolean bigSlide = Math.abs(nowX - slideBigX) < bitmapWidth / 2;
  if (rightY && lowSlide) {
   isLowerMoving = true;
  } else if (rightY && bigSlide) {
   isUpperMoving = true;
   //点击了游标外部 的线上
  } else if (nowX >= lineStart && nowX <= slideLowX - bitmapWidth / 2 && rightY) {
   slideLowX = (int) nowX;
   updateRange();
   postInvalidate();
  } else if (nowX <= lineEnd && nowX >= slideBigX + bitmapWidth / 2 && rightY) {
   slideBigX = (int) nowX;
   updateRange();
   postInvalidate();
  }
  break;
  case MotionEvent.ACTION_MOVE:
  //左边游标是运动状态
  if (isLowerMoving) {
   //当前 X坐标在线上 且在右边游标的左边
   if (nowX <= slideBigX - bitmapWidth && nowX >= lineStart - bitmapWidth / 2) {
   slideLowX = (int) nowX;
   if (slideLowX < lineStart) {
    slideLowX = lineStart;
   }
   //更新进度
   updateRange();
   postInvalidate();
   }
  } else if (isUpperMoving) {
   //当前 X坐标在线上 且在左边游标的右边
   if (nowX >= slideLowX + bitmapWidth && nowX <= lineEnd + bitmapWidth / 2) {
   slideBigX = (int) nowX;
   if (slideBigX > lineEnd) {
    slideBigX = lineEnd;
   }
   //更新进度
   updateRange();
   postInvalidate();
   }
  }
  break;
  //手指抬起
  case MotionEvent.ACTION_UP:
  isUpperMoving = false;
  isLowerMoving = false;
  break;
  default:
  break;
 }
 return true;
 }
 private void updateRange() {
 //当前 左边游标数值
 smallRange = computRange(slideLowX);
 //当前 右边游标数值
 bigRange = computRange(slideBigX);
 //接口 实现值的传递
 if (onRangeListener != null) {
  onRangeListener.onRange(smallRange, bigRange);
 }
 }
 /**
 * 获取当前值
 */
 private float computRange(float range) {
 return (range - lineStart) * (bigValue - smallValue) / lineLength + smallValue;
 }
 public int dip2px(Context context, float dpValue) {
 final float scale = context.getResources().getDisplayMetrics().density;
 return (int) (dpValue * scale + 0.5f);
 }
// /**
// * 画刻度
// */
// protected void drawRule(Canvas canvas) {
// if (paintRule == null) {
//  paintRule = new Paint();
// }
// paintRule.setStrokeWidth(1);
// paintRule.setTextSize(ruleTextSize);
// paintRule.setTextAlign(Paint.Align.CENTER);
// paintRule.setAntiAlias(true);
// //遍历 equal份,画刻度
// for (int i = smallValue; i <= bigValue; i += (bigValue - smallValue) / equal) {
//  float degX = lineStart + i * lineLength / (bigValue - smallValue);
//  int degY = lineY - ruleLineHeight;
//  paintRule.setColor(ruleColor);
//  canvas.drawLine(degX, lineY, degX, degY, paintRule);
//  paintRule.setColor(ruleTextColor);
//  canvas.drawText(String.valueOf(i) + ruleUnit, degX, degY, paintRule);
// }
// }
 /**
 * 写个接口 用来传递最大最小值
 */
 public interface onRangeListener {
 void onRange(float low, float big);
 }
 private onRangeListener onRangeListener;
 public void setOnRangeListener(DoubleSlideSeekBar.onRangeListener onRangeListener) {
 this.onRangeListener = onRangeListener;
 }
}

<?xml version="1.0" encoding="utf-8"?>
<resources>
 <!--线（进度条）宽度-->
 <attr name="lineHeight" format="dimension" />
 <!--字的大小 100元-->
 <attr name="textSize" format="dimension" />
 <!--字的颜色 100元-->
 <attr name="textColor" format="color" />
 <!--两个游标内部 线（进度条）的颜色-->
 <attr name="inColor" format="color" />
 <!--两个游标外部 线（进度条）的颜色-->
 <attr name="outColor" format="color" />
 <!--左边图标的图片-->
 <attr name="imageLow" format="reference"/>
 <!--右边图标 的图片-->
 <attr name="imageBig" format="reference"/>
 <!--游标 图片宽度-->
 <attr name="imagewidth" format="dimension" />
 <!--游标 图片高度-->
 <attr name="imageheight" format="dimension" />
 <!--是否有刻度线-->
 <attr name="hasRule" format="boolean" />
 <!--刻度的颜色-->
 <attr name="ruleColor" format="color" />
 <!--刻度上边的字 的颜色-->
 <attr name="ruleTextColor" format="color" />
 <!--单位 元-->
 <attr name="unit" format="string"/>
 <!--单位份数-->
 <attr name="equal" format="integer"/>
 <!--刻度单位 $-->
 <attr name="ruleUnit" format="string"/>
 <!--刻度上边文字的size-->
 <attr name="ruleTextSize" format="dimension" />
 <!--刻度线的高度-->
 <attr name="ruleLineHeight" format="dimension" />
 <!--选择器的最大值-->
 <attr name="bigValue" format="integer"/>
 <!--选择器的最小值-->
 <attr name="smallValue" format="integer"/>
 <declare-styleable name="DoubleSlideSeekBar">
  <attr name="lineHeight" />
  <attr name="textSize" />
  <attr name="textColor" />
  <attr name="inColor" />
  <attr name="outColor" />
  <attr name="imageLow"/>
  <attr name="imageBig"/>
  <attr name="imagewidth" />
  <attr name="imageheight" />
  <attr name="hasRule" />
  <attr name="ruleColor" />
  <attr name="ruleTextColor" />
  <attr name="unit" />
  <attr name="equal" />
  <attr name="ruleUnit" />
  <attr name="ruleTextSize" />
  <attr name="ruleLineHeight" />
  <attr name="bigValue" />
  <attr name="smallValue" />
 </declare-styleable>
</resources> 

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 xmlns:custom="http://schemas.android.com/apk/res-auto"
 tools:context=".MainActivity"
 android:orientation="vertical">
 <com.XXX.XXX.DoubleSlideSeekBar
  android:id="@+id/doubleslide_withrule"
  android:layout_marginTop="20dp"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  custom:lineHeight="6dp"
  custom:textSize="12sp"
  custom:textColor="#0628e4"
  custom:inColor="#f10a0a"
  custom:outColor="#af08e2"
  custom:imagewidth="20dp"
  custom:imageheight="20dp"
  custom:hasRule="true"
  custom:ruleColor="#0e0e0e"
  custom:ruleTextColor="#f74104"
  custom:equal="10"
  custom:ruleTextSize="8sp"
  custom:ruleLineHeight="10dp"
  />
 <TextView
  android:id="@+id/tv_min_rule"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="0"
  android:layout_marginTop="10dp"></TextView>
 <TextView
  android:id="@+id/tv_max_rule"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="0"
  android:layout_marginTop="10dp"></TextView>
</LinearLayout>

public class MainActivity extends AppCompatActivity {
 private DoubleSlideSeekBar mDoubleslideWithrule;
 private TextView mTvMinRule;
 private TextView mTvMaxRule;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  mDoubleslideWithrule = (DoubleSlideSeekBar) findViewById(R.id.doubleslide_withrule);
  mTvMinRule = (TextView) findViewById(R.id.tv_min_rule);
  mTvMaxRule = (TextView) findViewById(R.id.tv_max_rule);
  setListener();
 }
 private void setListener() {
  mDoubleslideWithrule.setOnRangeListener(new DoubleSlideSeekBar.onRangeListener() {
   @Override
   public void onRange(float low, float big) {
    mTvMinRule.setText("最小值" + String.format("%.0f" , low));
    mTvMaxRule.setText("最大值" + String.format("%.0f" , big));
   }
  });
 }
}