自定义Android可滑动控件源码

package com.qin.scrollerview; import android.content.Context; import android.util.AttributeSet; import android.util.Log; import android.view.MotionEvent; import android.view.VelocityTracker; import android.view.View; import android.view.ViewConfiguration; import android.view.ViewGroup; import android.widget.LinearLayout; import android.widget.Scroller; public class MultiViewGroup extends ViewGroup { private Context mContext; private static String TAG = "MultiViewGroup"; private int curScreen = 0 ; private Scroller mScroller = null ; private static final int TOUCH_STATE_REST = 0; private static final int TOUCH_STATE_SCROLLING = 1; private int mTouchState = TOUCH_STATE_REST; public static int SNAP_VELOCITY = 600 ; private int mTouchSlop = 0 ; private float mLastionMotionX = 0 ; private float mLastMotionY = 0 ; private VelocityTracker mVelocityTracker = null ; public MultiViewGroup(Context context) { super(context); mContext = context; init(); } public MultiViewGroup(Context context, AttributeSet attrs) { super(context, attrs); mContext = context; init(); } private void init() { mScroller = new Scroller(mContext); LinearLayout oneLL = new LinearLayout(mContext); oneLL.setBackgroundDrawable(getResources().getDrawable(R.drawable.bg1)); addView(oneLL); LinearLayout twoLL = new LinearLayout(mContext); twoLL.setBackgroundDrawable(getResources().getDrawable(R.drawable.bg2)); addView(twoLL); LinearLayout threeLL = new LinearLayout(mContext); threeLL.setBackgroundDrawable(getResources().getDrawable(R.drawable.bg3)); addView(threeLL); LinearLayout fourLL = new LinearLayout(mContext); fourLL.setBackgroundDrawable(getResources().getDrawable(R.drawable.bg4)); addView(fourLL); mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop(); } public void moveToLeftSide(){ if (curScreen >= getChildCount() - 1) { return; } curScreen++ ; Log.i(TAG, "----moveToLeftSide---- curScreen " + curScreen); Log.i(TAG, "----width " + getWidth()); mScroller.startScroll((curScreen-1) * getWidth(), 0, getWidth(), 0, 3000); scrollTo(curScreen * getWidth(), 0); invalidate(); } public void moveToRightSide(){ if (curScreen <= 0) { return; } curScreen-- ; Log.i(TAG, "----moveToRightSide---- curScreen " + curScreen); mScroller.startScroll((curScreen + 1) * getWidth(), 0, -getWidth(), 0, 3000); scrollTo(curScreen * getWidth(), 0); invalidate(); } public void stopMove(){ Log.v(TAG, "----stopMove ----"); if(mScroller != null){ if(!mScroller.isFinished()){ int scrollCurX= mScroller.getCurrX() ; //calculate destination screen int descScreen = ( scrollCurX + getWidth() / 2) / getWidth() ; Log.i(TAG, "----mScroller.is not finished ---- shouldNext" + descScreen); Log.i(TAG, "----mScroller.is not finished ---- scrollCurX " + scrollCurX); mScroller.abortAnimation(); scrollTo(descScreen * getWidth() , 0); mScroller.forceFinished(true); curScreen = descScreen ; } } else Log.i(TAG, "----OK mScroller.is finished ---- "); } @Override public void computeScroll() { // TODO Auto-generated method stub Log.e(TAG, "computeScroll"); if (mScroller.computeScrollOffset()) { Log.e(TAG, mScroller.getCurrX() + "======" + mScroller.getCurrY()); scrollTo(mScroller.getCurrX(), mScroller.getCurrY()); Log.e(TAG, "### getleft is " + getLeft() + " ### getRight is " + getRight()); postInvalidate(); } else Log.i(TAG, "have done the scoller -----"); } @Override public boolean onInterceptTouchEvent(MotionEvent ev) { // TODO Auto-generated method stub Log.e(TAG, "onInterceptTouchEvent-slop:" + mTouchSlop); final int action = ev.getAction(); if ((action == MotionEvent.ACTION_MOVE) && (mTouchState != TOUCH_STATE_REST)) { return true; } final float x = ev.getX(); final float y = ev.getY(); switch (action) { case MotionEvent.ACTION_MOVE: Log.e(TAG, "onInterceptTouchEvent move"); final int xDiff = (int) Math.abs(mLastionMotionX - x); if (xDiff > mTouchSlop) { mTouchState = TOUCH_STATE_SCROLLING; } break; case MotionEvent.ACTION_DOWN: Log.e(TAG, "onInterceptTouchEvent down"); mLastionMotionX = x; mLastMotionY = y; Log.e(TAG, "scroller is finished" + mScroller.isFinished() + ""); mTouchState = mScroller.isFinished() ? TOUCH_STATE_REST : TOUCH_STATE_SCROLLING; break; case MotionEvent.ACTION_CANCEL: case MotionEvent.ACTION_UP: Log.e(TAG, "onInterceptTouchEvent up or cancel"); mTouchState = TOUCH_STATE_REST; break; } Log.e(TAG, mTouchState + "====" + TOUCH_STATE_REST); return mTouchState != TOUCH_STATE_REST; } public boolean onTouchEvent(MotionEvent event){ Log.i(TAG, "--- onTouchEvent--> " ); // TODO Auto-generated method stub Log.e(TAG, "onTouchEvent start"); if (mVelocityTracker == null) { Log.e(TAG, "onTouchEvent start-------** VelocityTracker.obtain"); mVelocityTracker = VelocityTracker.obtain(); } mVelocityTracker.addMovement(event); super.onTouchEvent(event); float x = event.getX(); float y = event.getY(); switch(event.getAction()){ case MotionEvent.ACTION_DOWN: if(mScroller != null){ if(!mScroller.isFinished()){ mScroller.abortAnimation(); } } mLastionMotionX = x ; break ; case MotionEvent.ACTION_MOVE: int deltaX = (int)(mLastionMotionX - x ); int deltaY = (int)(mLastMotionY - y); if (Math.abs(deltaX) < Math.abs(deltaY)) { break; } scrollBy(deltaX, 0); Log.e(TAG, "--- MotionEvent.ACTION_MOVE--> detaX is " + deltaX ); mLastionMotionX = x ; break ; case MotionEvent.ACTION_UP: final VelocityTracker velocityTracker = mVelocityTracker ; velocityTracker.computeCurrentVelocity(1000); int velocityX = (int) velocityTracker.getXVelocity() ; Log.e(TAG , "---velocityX---" + velocityX); if (velocityX > SNAP_VELOCITY && curScreen > 0) { // Fling enough to move left Log.e(TAG, "snap left"); snapToScreen(curScreen - 1); } else if(velocityX < -SNAP_VELOCITY && curScreen < (getChildCount()-1)){ Log.e(TAG, "snap right"); snapToScreen(curScreen + 1); } else{ snapToDestination(); } if (mVelocityTracker != null) { mVelocityTracker.recycle(); mVelocityTracker = null; } mTouchState = TOUCH_STATE_REST ; break; case MotionEvent.ACTION_CANCEL: mTouchState = TOUCH_STATE_REST ; break; } return true ; } private void snapToDestination(){ int scrollX = getScrollX() ; int scrollY = getScrollY() ; Log.e(TAG, "### onTouchEvent snapToDestination ### scrollX is " + scr