<declare-styleable name="DragView"> <attr name="icon_drag" format="reference"/> <attr name="color_circle" format="color"/> <attr name="dot_num" format="integer"/> </declare-styleable>

public class CircleView extends View {
/** * 默认颜色 */ private final int DEFAULT_COLOR = Color.LTGRAY;
/** * 默认半径dp */ private final float DEFAULT_RADIUS = 32;
private int mColor;
private Paint mCirclePaint;
private float mRadius;
private float mCenterX;
private float mCenterY;
public CircleView(Context context) {
this(context, null);
}
public CircleView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public CircleView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.DragView);
mColor = array.getColor(R.styleable.DragView_color_circle,DEFAULT_COLOR);
mCirclePaint = new Paint();
mCirclePaint.setColor(mColor);
mCenterY = mCenterX = mRadius = getMeasuredWidth() == 0?DEFAULT_RADIUS:getMeasuredWidth()/2;
array.recycle();
}
public float getRadius(){
return mRadius;
}
public int getColor() {
return mColor;
}
@Override protected void onDraw(Canvas canvas) {
canvas.drawCircle(mCenterX,mCenterY,mRadius,mCirclePaint);
}
}

public class DragView extends RelativeLayout implements View.OnTouchListener {
private Drawable mDragIcon;
//拖动图标 private ImageView mDragView;
//拖动图标ImageView private int mCircleColor;
//圆的颜色 private Context mContext;
//上下文 private int mDotNum;
//节点数量 private int mWidth;
//组件的宽度 private int mHight;
//组件的高度 private int mCircleRadius;
//园的半径 private int mDragWidth;
//拖动图标的宽度 private int mLineWidth,mLineHeight;
//中间线的长宽 private float mStartX;
//开始拖动的屏幕坐标 private float mCurX;
//开始拖动的触点坐标 private float mMinX;
//拖动范围的最小值 private float mMaxX;
//拖动范围的最大值 private OnNodeSelect mOnNodeSelect;
//回调接口 public DragView(Context context) {
this(context,null);
}
public DragView(Context context, AttributeSet attrs) {
this(context, attrs,0);
}
public DragView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
TypedArray array=context.obtainStyledAttributes(attrs, R.styleable.DragView);
mDragIcon=array.getDrawable(R.styleable.DragView_icon_drag);
mCircleColor=array.getColor(R.styleable.DragView_color_circle,Color.WHITE);
mDotNum=array.getInt(R.styleable.DragView_dot_num,2);
array.recycle();
mContext=context;
initView();
}
/** *视图初始化，这个方法的作用是把所有的视图添加进来，并做一些初始化的配置 * 其实可以用LayoutInflater把xml的布局文件加载进来，这样比较简便 */ public void initView(){
for (int i=0;
i<mDotNum;
i++){
CircleView circleView=new CircleView(mContext);
circleView.setOnTouchListener(this);
addView(circleView);
}
View view=new View(mContext);
view.setBackgroundColor(mCircleColor);
addView(view);
// TODO: 2016/4/21 top not right mDragView=new ImageView(mContext);
mDragView.setImageDrawable(mDragIcon);
mDragView.setOnTouchListener(this);
addView(mDragView);
}
/** *这一步主要是为了测量、配置每个view的大小，以便于后面触摸事件的处理 */ @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
mWidth=getMeasuredWidth();
mHight=getMeasuredHeight();
mCircleRadius=dp2px(mContext,32);
mDragWidth=dp2px(mContext,50);
mLineWidth=mWidth-mDragWidth;
mLineHeight=mCircleRadius/2;
int count=getChildCount();
for (int i=0;
i<count;
i++){
View view=getChildAt(i);
LinearLayout.LayoutParams params;
if (view instanceof CircleView){
params=new LinearLayout.LayoutParams(mCircleRadius,mCircleRadius);
view.setLayoutParams(params);
}
else if (view instanceof ImageView){
params=new LinearLayout.LayoutParams(mDragWidth,mDragWidth);
view.setLayoutParams(params);
}
else {
params=new LinearLayout.LayoutParams(mLineWidth,mLineHeight);
view.setLayoutParams(params);
}
}
}
/** *这一步主要是为了放置每个view的位置，如果用LayoutInflater加载布局文件，那这一步就可以省略了 */ @Override protected void onLayout(boolean changed, int l, int t, int r, int b) {
// super.onLayout(changed, l, t, r, b);
if (changed){
int count =getChildCount();
int dLeft=0;
int dTop=mHight/2-mDragWidth/2;
int cLeft=mDragWidth/2-mCircleRadius/2;
int cTop=dTop+mDragWidth/2-mCircleRadius/2;
int lLeft=mDragWidth/2;
int lTop=dTop+mDragWidth/2-mLineHeight/2;
mMinX=dLeft;
mMaxX=dLeft+mLineWidth;
int cIndex=0;
int cSpace=0;
for (int i=0;
i<count;
i++){
View view=getChildAt(i);
if (view instanceof CircleView){
cLeft=cLeft+cSpace;
view.layout(cLeft,cTop,cLeft+mCircleRadius,cTop+mCircleRadius);
cIndex++;
cSpace=cIndex*mLineWidth;
}
else if (view instanceof ImageView){
view.layout(dLeft,dTop,dLeft+mDragWidth,dTop+mDragWidth);
}
else {
view.layout(lLeft,lTop,lLeft+mLineWidth,lTop+mLineHeight);
}
}
}
}
/** *触碰事件的处理，这是自定义view比较重要的地方 */ @Override public boolean onTouch(View v, MotionEvent event) {
if (v instanceof ImageView){
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN: mStartX = (int) event.getRawX();
mCurX = v.getTranslationX();
//获取view的偏移量 v.setPressed(true);
break;
case MotionEvent.ACTION_MOVE: float x = mCurX + event.getRawX() - mStartX;
if (x >= 0 && x <= mMaxX - mMinX) {
v.setTranslationX(mCurX + event.getRawX() - mStartX);
}
break;
case MotionEvent.ACTION_UP: case MotionEvent.ACTION_CANCEL: int distance=(int) (event.getRawX()-mStartX);
if (distance>0){
if (Math.abs(distance)>mLineWidth/2){
v.setTranslationX(mCurX + event.getRawX() - mStartX);
setAnim(mLineWidth,1);
}
else {
v.setTranslationX(mCurX + event.getRawX() - mStartX);
setAnim(0,0);
}
}
else if (distance<0){
if (Math.abs(distance)>mLineWidth/2){
v.setTranslationX(mCurX + event.getRawX() - mStartX);
setAnim(0,0);
}
else {
v.setTranslationX(mCurX + event.getRawX() - mStartX);
setAnim(mLineWidth,1);
}
}
break;
}
}
else if (v instanceof CircleView){
switch (event.getAction()) {
case MotionEvent.ACTION_UP: if (event.getRawX()>getDisplayWidth()/2){
setAnim(mLineWidth,1);
}
else {
setAnim(0,0);
}
break;
}
}
return true;
}
//设置平移动画 private void setAnim(float moveX, final int scrollPosition) {
ObjectAnimator animator = ObjectAnimator.ofFloat(mDragView, "translationX", mDragView.getTranslationX(), moveX);
animator.setDuration(300);
animator.start();
if (mOnNodeSelect != null) {
mOnNodeSelect.onNodeSelect(scrollPosition);
}
}
public void setNodeSelectListener(OnNodeSelect onNodeSelect) {
mOnNodeSelect = onNodeSelect;
}
//事件回调接口 public interface OnNodeSelect {
void onNodeSelect(int position);
}
//dp转px public int dp2px(Context context, float dpValue) {
final float scale = context.getResources().getDisplayMetrics().density;
return (int) (dpValue * scale + 0.5f);
}
//获取屏幕宽度 public int getDisplayWidth(){
DisplayMetrics metrics=new DisplayMetrics();
((Activity)mContext).getWindowManager().getDefaultDisplay().getMetrics(metrics);
return metrics.widthPixels;
}
}

<com.pengkv.apple.weight.DragView android:id="@+id/view_drag" android:layout_width="200dp" app:icon_drag="@drawable/ic_drag" app:color_circle="#CCCCCC" app:dot_num="2" android:layout_height="60dp"/>

dragView=(DragView)view.findViewById(R.id.view_drag);
dragView.setNodeSelectListener(new DragView.OnNodeSelect() {
@Override public void onNodeSelect(int position) {
Toast.makeText(getActivity(),"我选择了"+position,Toast.LENGTH_SHORT).show();
}
}
);