/*
* Created by LuaView.
* Copyright (c) 2017, Alibaba Group. All rights reserved.
*
* This source code is licensed under the MIT.
* For the full copyright and license information,please view the LICENSE file in the root directory of this source tree.
*/
package com.taobao.luaview.view.viewpager;
import android.content.Context;
import android.os.Handler;
import android.os.Message;
import android.support.v4.view.MotionEventCompat;
import android.support.v4.view.PagerAdapter;
import android.view.MotionEvent;
import android.view.View;
import java.lang.ref.WeakReference;
public class AutoScrollViewPager extends LoopViewPager {
public static final int DEFAULT_INTERVAL = 3000;
public static final int LEFT = 0;
public static final int RIGHT = 1;
/**
* do nothing when sliding at the last or first item
**/
public static final int SLIDE_BORDER_MODE_NONE = 0;
/**
* cycle when sliding at the last or first item
**/
public static final int SLIDE_BORDER_MODE_CYCLE = 1;
/**
* deliver event to parent when sliding at the last or first item
**/
public static final int SLIDE_BORDER_MODE_TO_PARENT = 2;
/**
* auto scroll time in milliseconds, default is {@link #DEFAULT_INTERVAL}
**/
private long interval = DEFAULT_INTERVAL;
/**
* auto scroll direction, default is {@link #RIGHT}
**/
private int direction = RIGHT;
/**
* whether stop auto scroll when touching, default is true
**/
private boolean stopScrollWhenTouch = true;
/**
* how to process when sliding at the last or first item, default is {@link #SLIDE_BORDER_MODE_NONE}
**/
private int slideBorderMode = SLIDE_BORDER_MODE_NONE;
private Handler handler;
private boolean reverseDirection = false;
private boolean isAutoScroll = false;
private boolean isStopByUIChange = false;
private boolean isStopByTouch = false;
private float touchX = 0f, downX = 0f;
private boolean canAutoScroll = false;
public static final int SCROLL_WHAT = 0;
public AutoScrollViewPager(Context context) {
super(context);
init();
}
private void init() {
handler = new MyHandler(this);
}
/**
* 设置是否可以自动滚动，所有自动滚动的逻辑都受该参数影响
*
* @param canAutoScroll
*/
public void setCanAutoScroll(boolean canAutoScroll) {
this.canAutoScroll = canAutoScroll;
}
/**
* start auto scroll, first scroll delay time is {@link #getInterval()}
*/
public void startAutoScroll() {
isAutoScroll = true;
sendScrollMessage(interval);
}
/**
* start auto scroll
*
* @param delayTimeInMills first scroll delay time
*/
public void startAutoScroll(int delayTimeInMills) {
isAutoScroll = true;
sendScrollMessage(delayTimeInMills);
}
/**
* stop auto scroll
*/
public void stopAutoScroll() {
isAutoScroll = false;
handler.removeMessages(SCROLL_WHAT);
}
private void sendScrollMessage(long delayTimeInMills) {
/** remove messages before, keeps one message is running at most **/
handler.removeMessages(SCROLL_WHAT);
handler.sendEmptyMessageDelayed(SCROLL_WHAT, delayTimeInMills);
}
/**
* scroll only once
*/
public void scrollOnce() {
PagerAdapter adapter = getAdapter();
int realPosition = getCurrentItem();
int realCount;
if (adapter == null || (realCount = getRealCount()) <= 1) {
return;
}
//调整方向
if (reverseDirection) {
if (direction == RIGHT && realPosition + 1 >= realCount) {
direction = LEFT;
} else if (direction == LEFT && realPosition - 1 < 0) {
direction = RIGHT;
}
}
if (isLooping()) {
setCurrentItem(direction == LEFT ? (realPosition - 1) % getCount() : (realPosition + 1) % getCount(), true);
} else {
int nextItem = (direction == LEFT) ? --realPosition : ++realPosition;
if (nextItem < 0) {
setCurrentItem(realCount - 1, true);
} else if (nextItem == realCount) {
setCurrentItem(0, true);
} else {
setCurrentItem(nextItem, true);
}
}
}
/**
* <ul>
* if stopScrollWhenTouch is true
* <li>if event is down, stop auto scroll.</li>
* <li>if event is up, start auto scroll again.</li>
* </ul>
*
* bugfix: 增加ev.getAction() == MotionEvent.ACTION_CANCEL条件判断,Action Cancel事件发生的时候也要重新开始自动滚动
*
*/
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
if (!canAutoScroll) {
return super.dispatchTouchEvent(ev);
}
int action = MotionEventCompat.getActionMasked(ev);
if (stopScrollWhenTouch) {
if ((action == MotionEvent.ACTION_DOWN) && isAutoScroll) {
isStopByTouch = true;
stopAutoScroll();
} else if ((ev.getAction() == MotionEvent.ACTION_UP || ev.getAction() == MotionEvent.ACTION_CANCEL) && isStopByTouch) {
startAutoScroll();
}
}
// if (slideBorderMode == SLIDE_BORDER_MODE_TO_PARENT || slideBorderMode == SLIDE_BORDER_MODE_CYCLE) {
// touchX = ev.getX();
// if (ev.getAction() == MotionEvent.ACTION_DOWN) {
// downX = touchX;
// }
// int currentItem = getCurrentItem();
// PagerAdapter adapter = getAdapter();
// int pageCount = adapter == null ? 0 : adapter.getCount();
// /**
// * current index is first one and slide to right or current index is last one and slide to left.<br/>
// * if slide border mode is to parent, then requestDisallowInterceptTouchEvent false.<br/>
// * else scroll to last one when current item is first one, scroll to first one when current item is last
// * one.
// */
// if ((currentItem == 0 && downX <= touchX) || (currentItem == pageCount - 1 && downX >= touchX)) {
// if (slideBorderMode == SLIDE_BORDER_MODE_TO_PARENT) {
// getParent().requestDisallowInterceptTouchEvent(false);
// } else {
// if (pageCount > 1) {
// setCurrentItem(pageCount - currentItem - 1, false);
// }
//// getParent().requestDisallowInterceptTouchEvent(true);
// }
// return super.dispatchTouchEvent(ev);
// }
// }
//// getParent().requestDisallowInterceptTouchEvent(true);
return super.dispatchTouchEvent(ev);
}
private static class MyHandler extends Handler {
private final WeakReference<AutoScrollViewPager> autoScrollViewPager;
public MyHandler(AutoScrollViewPager autoScrollViewPager) {
this.autoScrollViewPager = new WeakReference<AutoScrollViewPager>(autoScrollViewPager);
}
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (msg.what) {
case SCROLL_WHAT:
AutoScrollViewPager pager = this.autoScrollViewPager.get();
if (pager != null) {
pager.scrollOnce();
pager.sendScrollMessage(pager.interval);
}
default:
break;
}
}
}
/**
* get auto scroll time in milliseconds, default is {@link #DEFAULT_INTERVAL}
*
* @return the interval
*/
public long getInterval() {
return interval;
}
/**
* set auto scroll time in milliseconds, default is {@link #DEFAULT_INTERVAL}
*
* @param interval the interval to set
*/
public void setInterval(long interval) {
this.interval = interval;
}
/**
* get auto scroll direction
*
* @return {@link #LEFT} or {@link #RIGHT}, default is {@link #RIGHT}
*/
public int getDirection() {
return (direction == LEFT) ? LEFT : RIGHT;
}
/**
* set auto scroll direction
*
* @param direction {@link #LEFT} or {@link #RIGHT}, default is {@link #RIGHT}
*/
public void setDirection(int direction) {
this.direction = direction;
}
/**
* whether stop auto scroll when touching, default is true
*
* @return the stopScrollWhenTouch
*/
public boolean isStopScrollWhenTouch() {
return stopScrollWhenTouch;
}
/**
* set whether stop auto scroll when touching, default is true
*
* @param stopScrollWhenTouch
*/
public void setStopScrollWhenTouch(boolean stopScrollWhenTouch) {
this.stopScrollWhenTouch = stopScrollWhenTouch;
}
/**
* get how to process when sliding at the last or first item
*
* @return the slideBorderMode {@link #SLIDE_BORDER_MODE_NONE}, {@link #SLIDE_BORDER_MODE_TO_PARENT},
* {@link #SLIDE_BORDER_MODE_CYCLE}, default is {@link #SLIDE_BORDER_MODE_NONE}
*/
public int getSlideBorderMode() {
return slideBorderMode;
}
/**
* set how to process when sliding at the last or first item
*
* @param slideBorderMode {@link #SLIDE_BORDER_MODE_NONE}, {@link #SLIDE_BORDER_MODE_TO_PARENT},
* {@link #SLIDE_BORDER_MODE_CYCLE}, default is {@link #SLIDE_BORDER_MODE_NONE}
*/
public void setSlideBorderMode(int slideBorderMode) {
this.slideBorderMode = slideBorderMode;
}
public void setReverseDirection(boolean reverseDirection) {
this.reverseDirection = reverseDirection;
}
@Override
protected void onVisibilityChanged(View changedView, int visibility) {
if (canAutoScroll && visibility == View.VISIBLE && isStopByUIChange) {
isStopByUIChange = false;
startAutoScroll();
}
super.onVisibilityChanged(changedView, visibility);
if (canAutoScroll && visibility != View.VISIBLE) {
isStopByUIChange = true;
stopAutoScroll();
}
}
@Override
protected void onDetachedFromWindow() {
super.onDetachedFromWindow();
if (!canAutoScroll) {
return;
}
isStopByUIChange = true;
stopAutoScroll();
}
}