滑动效果
?
package com.test.canvas;import java.util.HashMap;import java.util.Iterator;import java.util.Map;import android.content.Context;import android.content.res.TypedArray;import android.graphics.Rect;import android.os.Handler;import android.os.Message;import android.util.AttributeSet;import android.util.Log;import android.view.GestureDetector;import android.view.GestureDetector.SimpleOnGestureListener;import android.view.MotionEvent;import android.view.View;import android.view.ViewGroup;import android.view.animation.Interpolator;import android.widget.LinearLayout;import android.widget.Scroller;import android.widget.SpinnerAdapter;public class Switcher extends ViewGroup {private static final int SCROLL = 0;private static final int JUSTIFY = 1;private static final int DISMISS_CONTROLS = 2;//private static final int ANIMATION_DURATION = 750;//private static final int IDLE_TIMEOUT = 3 * 1000;private int mOrientation;//宽度或高度，具体根据Orientation来决定private int mSize;//private Drawable mDecreaseButtonDrawable;//private Drawable mIncreaseButtonDrawable;//private ImageButton mDecreaseButton;//private ImageButton mIncreaseButton;//private PopupWindow mDecreasePopup;//private PopupWindow mIncreasePopup;private int mIndex;private int mPosition;private Scroller mScroller;private Map<View, Integer> mViews;private SpinnerAdapter mAdapter;private int mPackedViews;private GestureDetector mGestureDetector;private Rect mGlobal;private int mAnimationDuration;public Switcher(Context context, AttributeSet attrs) {super(context, attrs);int[] linerarLayoutAttrs = {android.R.attr.orientation};TypedArray a = context.obtainStyledAttributes(attrs, linerarLayoutAttrs);mOrientation = a.getInteger(0, LinearLayout.HORIZONTAL);a.recycle();//a = context.obtainStyledAttributes(attrs, R.styleable.Switcher);//mDecreaseButtonDrawable = a.getDrawable(R.styleable.Switcher_decreaseButton);//mIncreaseButtonDrawable = a.getDrawable(R.styleable.Switcher_increaseButton);//mAnimationDuration = a.getInteger(R.styleable.Switcher_animationDuration, ANIMATION_DURATION);//mIdleTimeout = a.getInteger(R.styleable.Switcher_idleTimeout, IDLE_TIMEOUT);//a.recycle();//if(mDecreaseButtonDrawable == null) {//throw new IllegalArgumentException(a.getPositionDescription() + ": decreaseButton attrubute not specified.");//}//if(mIncreaseButtonDrawable == null) {//throw new IllegalArgumentException(a.getPositionDescription() + ": increaseButton attrubute not specified.");//}//mDecreaseButton = new ImageButton(context);//mDecreaseButton.setEnabled(false);//mDecreaseButton.setBackgroundDrawable(mDecreaseButtonDrawable);//mIncreaseButton = new ImageButton(context);//mIncreaseButton.setEnabled(false);//mIncreaseButton.setBackgroundDrawable(mIncreaseButtonDrawable);////mDecreaseButton.setOnClickListener(new OnClickListener() {//public void onClick(View v) {//setPreviousView();//}//});//mIncreaseButton.setOnClickListener(new OnClickListener() {//public void onClick(View v) {//setNextView();//}//});mScroller = new Scroller(context);mIndex = -1;mPosition = -1;mPackedViews = -1;mViews = new HashMap<View, Integer>();mGestureDetector = new GestureDetector(gestureListener);mGestureDetector.setIsLongpressEnabled(false);setFocusable(true);setFocusableInTouchMode(true);//mDecreasePopup = new PopupWindow(mDecreaseButton, mDecreaseButtonDrawable.getIntrinsicWidth(), mDecreaseButtonDrawable.getIntrinsicHeight());//mIncreasePopup = new PopupWindow(mIncreaseButton, mIncreaseButtonDrawable.getIntrinsicWidth(), mIncreaseButtonDrawable.getIntrinsicHeight());//mDecreasePopup.setAnimationStyle(android.R.style.Animation_Toast);//mIncreasePopup.setAnimationStyle(android.R.style.Animation_Toast);mGlobal = new Rect();}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {super.onMeasure(widthMeasureSpec, heightMeasureSpec);mSize = mOrientation == LinearLayout.HORIZONTAL? getMeasuredWidth() : getMeasuredHeight();}private int getPackedViews(int offset) {int size = mSize;int start = offset / size;int numViews = offset % size != 0? 1 : 0;//都是位操作，从左往右依次执行,如果offset能被size整除则直接得出结果，如果不能整除，则结果再加1.return start << 1 | numViews;}Handler handler = new Handler() {@Overridepublic void handleMessage(Message msg) {if (msg.what == DISMISS_CONTROLS) {//mDecreasePopup.dismiss();//mIncreasePopup.dismiss();return;}Log.v("", "handleMessage-what:"+msg.what);mScroller.computeScrollOffset();int currX = mScroller.getCurrX();int delta = mPosition - currX;mPosition = currX;int packed = getPackedViews(mPosition);manageViews(packed);scroll(delta);if (!mScroller.isFinished()) {Log.v("", "mScroller.isFinished()=false");handler.sendEmptyMessage(msg.what);} else {if (msg.what == SCROLL) {justify();} else {mIndex = mPosition / mSize;setupButtons();}}}};//private long mIdleTimeout;//最后的矫正private void justify() {int offset = mPosition % mSize;if (offset != 0) {int endPosition = mPosition - offset;//如果移动超过中线则...if (offset > mSize / 2) {endPosition += mSize;}mScroller.startScroll(mPosition, 0, endPosition - mPosition, 0);handler.sendEmptyMessage(JUSTIFY);} else {mIndex = mPosition / mSize;setupButtons();}}private void scroll(int offset) {if (mOrientation == LinearLayout.HORIZONTAL) {for (View view : mViews.keySet()) {view.offsetLeftAndRight(offset);}} else {for (View view : mViews.keySet()) {view.offsetTopAndBottom(offset);}}invalidate();}private void setupButtons() {//if (mAdapter != null) {//boolean enabled = mIndex > 0;//mDecreaseButton.setEnabled(enabled);//enabled = mIndex + 1 < mAdapter.getCount();//mIncreaseButton.setEnabled(enabled);//}}public void setSelection(int index, boolean animate) {if (index == mIndex) {return;}int endPosition = index * mSize;int diff = Math.abs(index - mIndex);int sign = index > mIndex? 1 : -1;mIndex = index;if (diff > 1) {mPosition = endPosition - sign * mSize;}if (animate) {mScroller.startScroll(mPosition, 0, endPosition - mPosition, 0, mAnimationDuration);handler.removeMessages(JUSTIFY);handler.removeMessages(SCROLL);handler.sendEmptyMessage(JUSTIFY);} else {mPosition = endPosition;manageViews(index << 1);setupButtons();invalidate();}}private void manageViews(int packedViews) {if (packedViews == mPackedViews) {return;}Log.v("", "manageViews-packedViews:"+packedViews);mPackedViews = packedViews;int startIdx = packedViews >> 1;int endIdx = startIdx + (packedViews & 1);//如果packedViews是奇数endIdx=startIdx,如果是偶数则endIdx=startIdx+1.int viewIdx = startIdx;while (viewIdx <= endIdx) {if (!mViews.containsValue(viewIdx)) {if (viewIdx >= 0 && viewIdx < mAdapter.getCount()) {View view = mAdapter.getView(viewIdx, null, this);mViews.put(view, viewIdx);addView(view);}}viewIdx++;}// remove not visible viewsIterator<View> iterator = mViews.keySet().iterator();while (iterator.hasNext()) {View view = iterator.next();int idx = mViews.get(view);if (idx < startIdx || idx > endIdx) {iterator.remove();removeView(view);}}}//public int getSelection() {//return mIndex;//}////public void setPreviousView() {//if (mAdapter != null && mIndex > 0) {//setSelection(mIndex-1, true);//setupDismiss();//}//}////public void setNextView() {//if (mAdapter != null && mIndex + 1 < mAdapter.getCount()) {//setSelection(mIndex+1, true);//setupDismiss();//}//}public void setAdapter(SpinnerAdapter adapter) {mAdapter = adapter;if (mAdapter != null) {setSelection(0, false);setupButtons();}}private void setupDismiss() {//handler.removeMessages(DISMISS_CONTROLS);//handler.sendEmptyMessageDelayed(DISMISS_CONTROLS, mIdleTimeout);}@Overridepublic boolean onTouchEvent(MotionEvent event) {boolean rc = mGestureDetector.onTouchEvent(event);//有数据时应该是没有机会执行里面的代码if (!rc && event.getAction() == MotionEvent.ACTION_UP) {justify();}return true;}SimpleOnGestureListener gestureListener = new SimpleOnGestureListener() {@Overridepublic boolean onDown(MotionEvent e) {requestFocus();popup();return true;}@Overridepublic boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {if (mAdapter != null) {int distance = (int) (mOrientation == LinearLayout.HORIZONTAL? distanceX : distanceY);int pos = mPosition + distance;if (pos >= 0 && pos < (mAdapter.getCount() - 1) * mSize) {mPosition = pos;int packed = getPackedViews(mPosition);manageViews(packed);scroll(-distance);return true;}}return false;}@Overridepublic boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {if (mAdapter != null) {Log.v("", "onFling");float velocity = mOrientation == LinearLayout.HORIZONTAL? velocityX : velocityY;mScroller.fling(mPosition, 0, (int) -velocity, 0,0, (mAdapter.getCount() - 1) * mSize,0, 0);handler.removeMessages(JUSTIFY);handler.removeMessages(SCROLL);handler.sendEmptyMessage(SCROLL);return true;}return false;}};@Overrideprotected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) {super.onFocusChanged(gainFocus, direction, previouslyFocusedRect);if (gainFocus) {popup();} else {handler.removeMessages(DISMISS_CONTROLS);//mDecreasePopup.dismiss();//mIncreasePopup.dismiss();}}private void popup() {//if (mDecreasePopup.isShowing() && mIncreasePopup.isShowing()) {//return;//}getGlobalVisibleRect(mGlobal);//if (mOrientation == LinearLayout.HORIZONTAL) {//mDecreasePopup.showAtLocation(this,//Gravity.NO_GRAVITY,//mGlobal.left, //mGlobal.centerY() - mDecreasePopup.getHeight()/2);//mIncreasePopup.showAtLocation(this,//Gravity.NO_GRAVITY,//mGlobal.right - mIncreasePopup.getWidth(), //mGlobal.centerY() - mIncreasePopup.getHeight()/2);//} else {//// TODO: re-position when Switcher is at the very top/bottom of screen//mDecreasePopup.showAtLocation(this,//Gravity.NO_GRAVITY,//mGlobal.centerX() - mDecreasePopup.getWidth()/2,//mGlobal.top-mDecreasePopup.getHeight());//mIncreasePopup.showAtLocation(this,//Gravity.NO_GRAVITY,//mGlobal.centerX() - mIncreasePopup.getWidth()/2,//mGlobal.bottom);//}setupDismiss();}@Overrideprotected void onLayout(boolean changed, int l, int t, int r, int b) {for (View view : mViews.keySet()) {if (view.getWidth() == 0) {// new View: not layout()edint idx = mViews.get(view);if (mOrientation == LinearLayout.HORIZONTAL) {int left = mSize * idx - mPosition;view.layout(left, 0, left+r-l, b-t);} else {int top = mSize * idx - mPosition;view.layout(0, top, r-l, top+b-t);}}}}@Overrideprotected void onDetachedFromWindow() {super.onDetachedFromWindow();//mDecreasePopup.dismiss();//mIncreasePopup.dismiss();}public void setInterpolator(Interpolator interpolator) {mScroller = new Scroller(getContext(), interpolator);}}??