自定义viewpager

来源：互联网发布：sql int转date 编辑：程序博客网时间：2024/06/10 15:56
import android.content.Context;import android.support.v4.view.ViewConfigurationCompat;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;import android.view.ViewConfiguration;import android.view.animation.DecelerateInterpolator;import android.widget.LinearLayout;import android.widget.Scroller;import com.zoomy.studio.locker.utils.L;public class ScrollerLayout extends LinearLayout {    private Scroller mScroller;    //判定为拖动的最小移动像素数    private int mTouchSlop;    //手机按下时的屏幕坐标    private float mXDown;   //手机当时所处的屏幕坐标    private float mXMove;    //上次触发ACTION_MOVE事件时的屏幕坐标    private float mXLastMove;   //界面可滚动的左边界    private int leftBorder;   //界面可滚动的右边界    private int rightBorder;    //当前索引    private int targetIndex;    private boolean isUp;    public ScrollerLayout(Context context){        this(context,null);    }    public ScrollerLayout(Context context, AttributeSet attrs) {        super(context, attrs);        mScroller = new Scroller(context,new DecelerateInterpolator(1.2f));        ViewConfiguration configuration = ViewConfiguration.get(context);        mTouchSlop = ViewConfigurationCompat.getScaledPagingTouchSlop(configuration);        setOrientation(HORIZONTAL);    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        super.onMeasure(widthMeasureSpec, heightMeasureSpec);        int childCount = getChildCount();        for (int i = 0; i < childCount; i++) {            View childView = getChildAt(i);            measureChild(childView, widthMeasureSpec, heightMeasureSpec);        }    }    @Override    protected void onLayout(boolean changed, int l, int t, int r, int b) {        super.onLayout(changed,l,t,r,b);        L.i("qgl", "ScrollerLayout onLayout change=" + changed);        if (changed) {//            int childCount = getChildCount();//            for (int i = 0; i < childCount; i++) {//                View childView = getChildAt(i);//                // 水平布局//                childView.layout(i * childView.getMeasuredWidth(), 0, (i + 1) * childView.getMeasuredWidth(), childView.getMeasuredHeight());//            }            // 初始化左右边界值            leftBorder = getChildAt(0).getLeft();            rightBorder = getChildAt(getChildCount() - 1).getRight();            scrollTo(getWidth(), 0);            targetIndex = 1;        }    }    @Override    public boolean onInterceptTouchEvent(MotionEvent ev) {        switch (ev.getAction()) {            case MotionEvent.ACTION_DOWN:                isUp = false;                mXDown = ev.getRawX();                mXLastMove = mXDown;                L.i("qgl onInterceptTouchEvent ACTION_DOWN  mXDown=" + mXDown + " mXLastMove=" + mXLastMove);                break;            case MotionEvent.ACTION_MOVE:                mXMove = ev.getRawX();                float diff = Math.abs(mXMove - mXDown);                mXLastMove = mXMove;                L.i("qgl onInterceptTouchEvent ACTION_MOVE  mXMove=" + mXMove + " mXLastMove=" + mXLastMove + " diff=" + diff);                // 当手指拖动值大于TouchSlop值时，认为应该进行滚动，拦截子控件的事件                if (diff > mTouchSlop) {                    L.i("qgl","ScrollerLayout 拦截了");                    return true;                }                break;        }        return super.onInterceptTouchEvent(ev);    }    float startx = 0;    float endx = 0;    @Override    public boolean onTouchEvent(MotionEvent event) {        switch (event.getAction()) {            case MotionEvent.ACTION_DOWN:                isUp = false;                startx = event.getX();                L.i("qgl  startx=" + startx);                break;            case MotionEvent.ACTION_MOVE:                L.i("qgl","ScrollerLayout ACTION_MOVE onPageScrolled 执行了 position="+targetIndex);                listener.onPageScrolled(targetIndex);                mXMove = event.getRawX();                L.i("qgl onTouchEvent ACTION_MOVE  mXMove=" + mXMove);                int scrolledX = (int) (mXLastMove - mXMove);                L.i("qgl onTouchEvent ACTION_MOVE  scrolledX=" + scrolledX + " getScrollX()=" + getScrollX());                L.i("qgl onTouchEvent ACTION_MOVE  getScrollX() + scrolledX =" + getScrollX() + scrolledX + " leftBorder=" + leftBorder);                if (getScrollX() + scrolledX < leftBorder) {                    scrollTo(leftBorder, 0);                    return true;                } else if (getScrollX() + getWidth() + scrolledX > rightBorder) {                    L.i("qgl onTouchEvent ACTION_MOVE  getScrollX() + getWidth() + scrolledX =" + getScrollX() + getWidth() + scrolledX + " rightBorder=" + rightBorder);                    scrollTo(rightBorder - getWidth(), 0);                    return true;                }                scrollBy(scrolledX, 0);                L.i("qgl onTouchEvent ACTION_MOVE scrolledX =" + scrolledX);                mXLastMove = mXMove;                break;            case MotionEvent.ACTION_UP:                endx = event.getX();                isUp = true;                L.i("qgl onTouchEvent ACTION_UP mxdown=" + mXDown + "  mXLastMove=" + mXLastMove);                // 当手指抬起时，根据当前的滚动值来判定应该滚动到哪个子控件的界面                if(Math.abs(mXLastMove-mXDown) > getWidth() /8){                    if(mXLastMove < mXDown){                        targetIndex++;                    }else {                        targetIndex--;                    }                }                L.i("qgl onTouchEvent ACTION_UP  targetIndex=" + targetIndex);                if(targetIndex >= getChildCount()){                    targetIndex = getChildCount() -1;                }                if(targetIndex < 0){                    targetIndex = 0;                }                int dx = targetIndex * getWidth() - getScrollX();                L.i("qgl onTouchEvent ACTION_UP  dx=" + dx);                mScroller.startScroll(getScrollX(), 0, dx, 0,300);                invalidate();                break;        }        return super.onTouchEvent(event);    }    @Override    public void computeScroll() {        if (mScroller.computeScrollOffset()) {            L.i("qgl","ScrollerLayout computeScroll onPageScrolled 执行了 position="+targetIndex);            listener.onPageScrolled(targetIndex);            scrollTo(mScroller.getCurrX(), mScroller.getCurrY());            invalidate();        }else {            if(isUp) {                L.i("qgl", "ScrollerLayout onPageSelected 执行了");                listener.onPageSelected(targetIndex);            }        }    }    private OnPageChangeListener listener;    public void addOnPageChangeListener(OnPageChangeListener listener){        this.listener = listener;    }    public interface OnPageChangeListener{        void onPageScrolled(int position);        void onPageSelected(int position);    }    public  void setCurrentItem(int position){        scrollTo(getWidth()*position, 0);        targetIndex = position;    }}
1 0