先做一些准备的工作
- 自定义的圆点
package widget;
/**
* 一个接口定义ViewFlow和之间的合同FlowIndicator
* FlowIndicator负责节目的视觉指示器的总观点
* 数量和当前视图可见。
*/
public interface FlowIndicator extends ViewFlow.ViewSwitchListener {
/**
* 设置当前ViewFlow。由ViewFlow当调用此方法
* FlowIndicator相连。
*/
public void setViewFlow(ViewFlow view);
/**
* 滚动的位置已经发生了改变。FlowIndicator可能实现这个
* 方法反映了当前位置
*/
public void onScrolled(int h, int v, int oldh, int oldv);
}
package widget;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.os.AsyncTask;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import com.example.administrator.viewpagercarousel.R;
/**
* 一个FlowIndicator画圆圈(一个为每个视图)。
* activeColor:定义用于画活动圆的颜色(默认为白色)
* inactiveColor:定义用于画不活跃的圆圈的颜色(默认为0 x44ffffff)
* inactiveType:定义如何画不活跃的圈子,中风或填补中风(默认)
* activeType:定义如何画活动圈,中风或填补填补(默认)
* 渐隐:定义时间(ms),直到指示器将淡出(默认为0 =从未淡出)
* 半径:定义圆半径(默认为4.0)
*/
public class CircleFlowIndicator extends View implements FlowIndicator,
Animation.AnimationListener {
private static final int STYLE_STROKE = 0;
private static final int STYLE_FILL = 1;
private float radius = 4;
private float circleSeparation = 2 * radius + radius;
private float activeRadius = 0.5f;
private int fadeOutTime = 0;
private final Paint mPaintInactive = new Paint(Paint.ANTI_ALIAS_FLAG);
private final Paint mPaintActive = new Paint(Paint.ANTI_ALIAS_FLAG);
private ViewFlow viewFlow;
private int currentScroll = 0;
private int flowWidth = 0;
private FadeTimer timer;
public Animation.AnimationListener animationListener = this;
private Animation animation;
private boolean mCentered = false;
/**
* 默认构造函数
*/
public CircleFlowIndicator(Context context) {
super(context);
initColors(0xFFFFFFFF, 0xFFFFFFFF, STYLE_FILL, STYLE_STROKE);
}
/**
* 构造函数使用一个增压泵
*/
public CircleFlowIndicator(Context context, AttributeSet attrs) {
super(context, attrs);
// Retrieve styles attributs 检索风格attributs
TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.CircleFlowIndicator);
// Gets the inactive circle type, defaulting to "fill" 变得不活跃的圆类型,默认为“填充”
int activeType = a.getInt(R.styleable.CircleFlowIndicator_activeType,
STYLE_FILL);
int activeDefaultColor = 0xFFFFFFFF;
// Get a custom inactive color if there is one 得到一个定制的如果有一个不活跃的颜色
int activeColor = a
.getColor(R.styleable.CircleFlowIndicator_activeColor,
activeDefaultColor);
// Gets the inactive circle type, defaulting to "stroke" 变得不活跃的圆类型,默认为“中风”
int inactiveType = a.getInt(
R.styleable.CircleFlowIndicator_inactiveType, STYLE_STROKE);
int inactiveDefaultColor = 0x44FFFFFF;
// Get a custom inactive color if there is one 得到一个定制的如果有一个不活跃的颜色
int inactiveColor = a.getColor(
R.styleable.CircleFlowIndicator_inactiveColor,
inactiveDefaultColor);
// Retrieve the radius 检索半径
radius = a.getDimension(R.styleable.CircleFlowIndicator_radius, 4.0f);
circleSeparation = a.getDimension(R.styleable.CircleFlowIndicator_circleSeparation, 2 * radius + radius);
activeRadius = a.getDimension(R.styleable.CircleFlowIndicator_activeRadius, 0.5f);
// Retrieve the fade out time 检索淡出
fadeOutTime = a.getInt(R.styleable.CircleFlowIndicator_fadeOut, 0);
mCentered = a.getBoolean(R.styleable.CircleFlowIndicator_centered, false);
initColors(activeColor, inactiveColor, activeType, inactiveType);
}
private void initColors(int activeColor, int inactiveColor, int activeType,
int inactiveType) {
// Select the paint type given the type attr 选择油漆类型类型attr
switch (inactiveType) {
case STYLE_FILL:
mPaintInactive.setStyle(Style.FILL);
break;
default:
mPaintInactive.setStyle(Style.STROKE);
}
mPaintInactive.setColor(inactiveColor);
// Select the paint type given the type attr 选择油漆类型类型attr
switch (activeType) {
case STYLE_STROKE:
mPaintActive.setStyle(Style.STROKE);
break;
default:
mPaintActive.setStyle(Style.FILL);
}
mPaintActive.setColor(activeColor);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
int count = 3;
if (viewFlow != null) {
count = viewFlow.getViewsCount();
}
//this is the amount the first circle should be offset to make the entire thing centered
//这是《第一圈》应该抵消使整个集中
float centeringOffset = 0;
int leftPadding = getPaddingLeft();
// Draw stroked circles 画抚摸着圆圈
for (int iLoop = 0; iLoop < count; iLoop++) {
canvas.drawCircle(leftPadding + radius
+ (iLoop * circleSeparation) + centeringOffset,
getPaddingTop() + radius, radius, mPaintInactive);
}
float cx = 0;
if (flowWidth != 0) {
// Draw the filled circle according to the current scroll 根据当前卷轴画的实心圆
cx = (currentScroll * circleSeparation) / flowWidth;
}
// The flow width has been upadated yet. Draw the default position 流宽度已经upadated呢。把默认的位置
canvas.drawCircle(leftPadding + radius + cx + centeringOffset, getPaddingTop()
+ radius, radius + activeRadius, mPaintActive);
}
@Override
public void onSwitched(View view, int position) {
}
@Override
public void setViewFlow(ViewFlow view) {
resetTimer();
viewFlow = view;
flowWidth = viewFlow.getWidth();
invalidate();
}
@Override
public void onScrolled(int h, int v, int oldh, int oldv) {
setVisibility(View.VISIBLE);
resetTimer();
flowWidth = viewFlow.getWidth();
if (viewFlow.getViewsCount() * flowWidth != 0) {
currentScroll = h % (viewFlow.getViewsCount() * flowWidth);
} else {
currentScroll = h;
}
invalidate();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
setMeasuredDimension(measureWidth(widthMeasureSpec),
measureHeight(heightMeasureSpec));
}
/**
* 决定这个视图的宽度
*
* @param measureSpec measureSpec挤进一个int
* @return视图的宽度,纪念从measureSpec约束
*/
private int measureWidth(int measureSpec) {
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
// We were told how big to be 我们被告知要多大
if (specMode == MeasureSpec.EXACTLY) {
result = specSize;
}
// Calculate the width according the views count 计算宽度显示视图
else {
int count = 3;
if (viewFlow != null) {
count = viewFlow.getViewsCount();
}
float temp = circleSeparation - 2 * radius;
result = (int) (getPaddingLeft() + getPaddingRight()
+ (count * 2 * radius) + (count - 1) * temp + 1);
if (specMode == MeasureSpec.AT_MOST) {
result = Math.min(result, specSize);
}
}
return result;
}
/**
* 的高度决定了这一观点
*
* @param measureSpec measureSpec挤进一个int
* @return视图的高度,从measureSpec纪念约束
*/
private int measureHeight(int measureSpec) {
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
// We were told how big to be
if (specMode == MeasureSpec.EXACTLY) {
result = specSize;
}
// Measure the height
else {
result = (int) (2 * radius + getPaddingTop() + getPaddingBottom() + 1);
// Respect AT_MOST value if that was what is called for by
// measureSpec
if (specMode == MeasureSpec.AT_MOST) {
result = Math.min(result, specSize);
}
}
return result;
}
/**
* Sets the fill color
*
* @param color ARGB value for the text
*/
public void setFillColor(int color) {
mPaintActive.setColor(color);
invalidate();
}
/**
* Sets the stroke color
*
* @param color ARGB value for the text
*/
public void setStrokeColor(int color) {
mPaintInactive.setColor(color);
invalidate();
}
/**
* Resets the fade out timer to 0. Creating a new one if needed
*/
private void resetTimer() {
// Only set the timer if we have a timeout of at least 1 millisecond
if (fadeOutTime > 0) {
// Check if we need to create a new timer
if (timer == null || timer._run == false) {
// Create and start a new timer
timer = new FadeTimer();
timer.execute();
} else {
// Reset the current tiemr to 0
timer.resetTimer();
}
}
}
/**
* Counts from 0 to the fade out time and animates the view away when
* reached
*/
private class FadeTimer extends AsyncTask<Void, Void, Void> {
// The current count
private int timer = 0;
// If we are inside the timing loop
private boolean _run = true;
public void resetTimer() {
timer = 0;
}
@Override
protected Void doInBackground(Void... arg0) {
while (_run) {
try {
// Wait for a millisecond
Thread.sleep(1);
// Increment the timer
timer++;
// Check if we've reached the fade out time
if (timer == fadeOutTime) {
// Stop running
_run = false;
}
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return null;
}
@Override
protected void onPostExecute(Void result) {
animation = AnimationUtils.loadAnimation(getContext(),
android.R.anim.fade_out);
animation.setAnimationListener(animationListener);
startAnimation(animation);
}
}
@Override
public void onAnimationEnd(Animation animation) {
setVisibility(View.GONE);
}
@Override
public void onAnimationRepeat(Animation animation) {
}
@Override
public void onAnimationStart(Animation animation) {
}
}
- 自定义的水平滚动(相当于Viewpager)
做准备工作:
再values文件夹下新建一个 attrs.xml,设置需要的一些属性如下:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<!--水平滚动-->
<declare-styleable name="ViewFlow">
<attr name="sidebuffer" format="integer"/>
</declare-styleable>
<!--圆点-->
<declare-styleable name="CircleFlowIndicator">
<attr name="activeColor" format="color"/>
<attr name="inactiveColor" format="color"/>
<attr name="radius" format="dimension"/>
<attr name="centered" format="boolean"/>
<attr name="fadeOut" format="integer"/>
<attr name="inactiveType">
<flag name="stroke" value="0"/>
<flag name="fill" value="1"/>
</attr>
<attr name="activeType">
<flag name="stroke" value="0"/>
<flag name="fill" value="1"/>
</attr>
<attr name="circleSeparation" format="dimension"/>
<attr name="activeRadius" format="dimension"/>
</declare-styleable>
</resources>
package widget;
import android.content.Context;
import android.content.res.Configuration;
import android.content.res.TypedArray;
import android.database.DataSetObserver;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.widget.AbsListView;
import android.widget.Adapter;
import android.widget.AdapterView;
import android.widget.Scroller;
import com.example.administrator.viewpagercarousel.R;
import java.util.ArrayList;
import java.util.LinkedList;
/**
* 相当于Viewpager
* 水平滚动{ @link ViewGroup }与物品从一个填充
* { @link适配器}。ViewFlow使用缓冲区来存储加载{ @link视图}年代。
* 缓冲区的默认大小是3目前两岸的元素
* } { @link视图可见,占总缓冲区大小3 * 2 + 1 = 7。的
* 缓冲区大小可以改变使用{ @code sidebuffer } xml属性。
*/
public class ViewFlow extends AdapterView<Adapter> {
private static final int SNAP_VELOCITY = 1000;
private static final int INVALID_SCREEN = -1;
private final static int TOUCH_STATE_REST = 0;
private final static int TOUCH_STATE_SCROLLING = 1;
private LinkedList<View> mLoadedViews;
private int mCurrentBufferIndex;
private int mCurrentAdapterIndex;
private int mSideBuffer = 2;
private Scroller mScroller;
private VelocityTracker mVelocityTracker;
private int mTouchState = TOUCH_STATE_REST;
private float mLastMotionX;
private int mTouchSlop;
private int mMaximumVelocity;
private int mCurrentScreen;
private int mNextScreen = INVALID_SCREEN;
private boolean mFirstLayout = true;
private ViewSwitchListener mViewSwitchListener;
private Adapter mAdapter;
private int mLastScrollDirection;
private AdapterDataSetObserver mDataSetObserver;
private FlowIndicator mIndicator;
private int mLastOrientation = -1;
private long timeSpan = 3000;
private Handler handler;
private OnGlobalLayoutListener orientationChangeListener = new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
getViewTreeObserver().removeGlobalOnLayoutListener(
orientationChangeListener);
setSelection(mCurrentAdapterIndex);
}
};
/**
* Receives call backs when a new {@link View} has been scrolled to.
*/
public static interface ViewSwitchListener {
/**
* This method is called when a new View has been scrolled to.
*
* @param view the {@link View} currently in focus.
* @param position The position in the adapter of the {@link View} currently in focus.
*/
void onSwitched(View view, int position);
}
public ViewFlow(Context context) {
super(context);
mSideBuffer = 3;
init();
}
public ViewFlow(Context context, int sideBuffer) {
super(context);
mSideBuffer = sideBuffer;
init();
}
public ViewFlow(Context context, AttributeSet attrs) {
super(context, attrs);
TypedArray styledAttrs = context.obtainStyledAttributes(attrs,
R.styleable.ViewFlow);
mSideBuffer = styledAttrs.getInt(R.styleable.ViewFlow_sidebuffer, 3);
init();
}
private void init() {
mLoadedViews = new LinkedList<View>();
mScroller = new Scroller(getContext());
final ViewConfiguration configuration = ViewConfiguration
.get(getContext());
mTouchSlop = configuration.getScaledTouchSlop();
mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
}
/**
* 启动自动轮播
*/
public void startAutoFlowTimer() {
handler = new Handler() {
@Override
public void handleMessage(Message msg) {
snapToScreen((mCurrentScreen + 1) % getChildCount());
Message message = handler.obtainMessage(0);
sendMessageDelayed(message, timeSpan);
}
};
Message message = handler.obtainMessage(0);
handler.sendMessageDelayed(message, timeSpan);
}
/**
* 停止自动轮播
*/
public void stopAutoFlowTimer() {
if (handler != null)
handler.removeMessages(0);
handler = null;
}
public void onConfigurationChanged(Configuration newConfig) {
if (newConfig.orientation != mLastOrientation) {
mLastOrientation = newConfig.orientation;
getViewTreeObserver().addOnGlobalLayoutListener(orientationChangeListener);
}
}
public int getViewsCount() {
return mSideBuffer;
}
/**
* 重新计算宽、高
* @param widthMeasureSpec
* @param heightMeasureSpec
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
final int width = MeasureSpec.getSize(widthMeasureSpec);
final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
if (widthMode != MeasureSpec.EXACTLY && !isInEditMode()) {
throw new IllegalStateException(
"ViewFlow can only be used in EXACTLY mode.");
}
final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
if (heightMode != MeasureSpec.EXACTLY && !isInEditMode()) {
throw new IllegalStateException(
"ViewFlow can only be used in EXACTLY mode.");
}
// The children are given the same width and height as the workspace
final int count = getChildCount();
for (int i = 0; i < count; i++) {
getChildAt(i).measure(widthMeasureSpec, heightMeasureSpec);
}
if (mFirstLayout) {
mScroller.startScroll(0, 0, mCurrentScreen * width, 0, 0);
mFirstLayout = false;
}
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
int childLeft = 0;
final int count = getChildCount();
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (child.getVisibility() != View.GONE) {
final int childWidth = child.getMeasuredWidth();
child.layout(childLeft, 0, childLeft + childWidth,
child.getMeasuredHeight());
childLeft += childWidth;
}
}
}
/**
* 事件分发
* @param ev
* @return
*/
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
if (getChildCount() == 0)
return false;
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(ev);
final int action = ev.getAction();
final float x = ev.getX();
switch (action) {
case MotionEvent.ACTION_DOWN:
/*
* If being flinged and user touches, stop the fling. isFinished
* will be false if being flinged.
*/
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}
// Remember where the motion event started
mLastMotionX = x;
mTouchState = mScroller.isFinished() ? TOUCH_STATE_REST
: TOUCH_STATE_SCROLLING;
if (handler != null)
handler.removeMessages(0);
break;
case MotionEvent.ACTION_MOVE:
final int xDiff = (int) Math.abs(x - mLastMotionX);
boolean xMoved = xDiff > mTouchSlop;
if (xMoved) {
// Scroll if the user moved far enough along the X axis
mTouchState = TOUCH_STATE_SCROLLING;
}
if (mTouchState == TOUCH_STATE_SCROLLING) {
// Scroll to follow the motion event
final int deltaX = (int) (mLastMotionX - x);
mLastMotionX = x;
final int scrollX = getScrollX();
if (deltaX < 0) {
if (scrollX > 0) {
scrollBy(Math.max(-scrollX, deltaX), 0);
}
} else if (deltaX > 0) {
final int availableToScroll = getChildAt(
getChildCount() - 1).getRight()
- scrollX - getWidth();
if (availableToScroll > 0) {
scrollBy(Math.min(availableToScroll, deltaX), 0);
}
}
return true;
}
break;
case MotionEvent.ACTION_UP:
if (mTouchState == TOUCH_STATE_SCROLLING) {
final VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
int velocityX = (int) velocityTracker.getXVelocity();
if (velocityX > SNAP_VELOCITY && mCurrentScreen > 0) {
// Fling hard enough to move left
snapToScreen(mCurrentScreen - 1);
} else if (velocityX < -SNAP_VELOCITY
&& mCurrentScreen < getChildCount() - 1) {
// Fling hard enough to move right
snapToScreen(mCurrentScreen + 1);
} else {
snapToDestination();
}
if (mVelocityTracker != null) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
}
mTouchState = TOUCH_STATE_REST;
if (handler != null) {
Message message = handler.obtainMessage(0);
handler.sendMessageDelayed(message, timeSpan);
}
break;
case MotionEvent.ACTION_CANCEL:
mTouchState = TOUCH_STATE_REST;
}
return false;
}
/**
* 触摸的监听
* @param ev
* @return
*/
@Override
public boolean onTouchEvent(MotionEvent ev) {
if (getChildCount() == 0)
return false;
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(ev);
final int action = ev.getAction();
final float x = ev.getX();
switch (action) {
case MotionEvent.ACTION_DOWN:
/**
* 如果被扔,用户触摸,停止扔。结束
*将假如果被扔。
*/
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}
// Remember where the motion event started
mLastMotionX = x;
mTouchState = mScroller.isFinished() ? TOUCH_STATE_REST
: TOUCH_STATE_SCROLLING;
if (handler != null)
handler.removeMessages(0);
break;
case MotionEvent.ACTION_MOVE:
final int xDiff = (int) Math.abs(x - mLastMotionX);
boolean xMoved = xDiff > mTouchSlop;
if (xMoved) {
// Scroll if the user moved far enough along the X axis
mTouchState = TOUCH_STATE_SCROLLING;
}
if (mTouchState == TOUCH_STATE_SCROLLING) {
// Scroll to follow the motion event
final int deltaX = (int) (mLastMotionX - x);
mLastMotionX = x;
final int scrollX = getScrollX();
if (deltaX < 0) {
if (scrollX > 0) {
scrollBy(Math.max(-scrollX, deltaX), 0);
}
} else if (deltaX > 0) {
final int availableToScroll = getChildAt(
getChildCount() - 1).getRight()
- scrollX - getWidth();
if (availableToScroll > 0) {
scrollBy(Math.min(availableToScroll, deltaX), 0);
}
}
return true;
}
break;
case MotionEvent.ACTION_UP:
if (mTouchState == TOUCH_STATE_SCROLLING) {
final VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
int velocityX = (int) velocityTracker.getXVelocity();
if (velocityX > SNAP_VELOCITY && mCurrentScreen > 0) {
// Fling hard enough to move left
snapToScreen(mCurrentScreen - 1);
} else if (velocityX < -SNAP_VELOCITY
&& mCurrentScreen < getChildCount() - 1) {
// Fling hard enough to move right
snapToScreen(mCurrentScreen + 1);
}
// else if (velocityX < -SNAP_VELOCITY
// && mCurrentScreen == getChildCount() - 1) {
// snapToScreen(0);
// }
// else if (velocityX > SNAP_VELOCITY
// && mCurrentScreen == 0) {
// snapToScreen(getChildCount() - 1);
// }
else {
snapToDestination();
}
if (mVelocityTracker != null) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
}
mTouchState = TOUCH_STATE_REST;
if (handler != null) {
Message message = handler.obtainMessage(0);
handler.sendMessageDelayed(message, timeSpan);
}
break;
case MotionEvent.ACTION_CANCEL:
snapToDestination();
mTouchState = TOUCH_STATE_REST;
}
return true;
}
/**
* 滚动改变
* @param h
* @param v
* @param oldh
* @param oldv
*/
@Override
protected void onScrollChanged(int h, int v, int oldh, int oldv) {
super.onScrollChanged(h, v, oldh, oldv);
if (mIndicator != null) {
/*
* The actual horizontal scroll origin does typically not match the
* perceived one. Therefore, we need to calculate the perceived
* horizontal scroll origin here, since we use a view buffer.
*/
int hPerceived = h + (mCurrentAdapterIndex - mCurrentBufferIndex)
* getWidth();
mIndicator.onScrolled(hPerceived, v, oldh, oldv);
}
}
private void snapToDestination() {
final int screenWidth = getWidth();
final int whichScreen = (getScrollX() + (screenWidth / 2))
/ screenWidth;
snapToScreen(whichScreen);
}
private void snapToScreen(int whichScreen) {
mLastScrollDirection = whichScreen - mCurrentScreen;
if (!mScroller.isFinished())
return;
whichScreen = Math.max(0, Math.min(whichScreen, getChildCount() - 1));
mNextScreen = whichScreen;
final int newX = whichScreen * getWidth();
final int delta = newX - getScrollX();
mScroller.startScroll(getScrollX(), 0, delta, 0, Math.abs(delta) * 2);
invalidate();
}
@Override
public void computeScroll() {
if (mScroller.computeScrollOffset()) {
scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
postInvalidate();
} else if (mNextScreen != INVALID_SCREEN) {
mCurrentScreen = Math.max(0,
Math.min(mNextScreen, getChildCount() - 1));
mNextScreen = INVALID_SCREEN;
postViewSwitched(mLastScrollDirection);
}
}
/**
* Scroll to the {@link View} in the view buffer specified by the index.
*
* @param indexInBuffer Index of the view in the view buffer.
*/
private void setVisibleView(int indexInBuffer, boolean uiThread) {
mCurrentScreen = Math.max(0,
Math.min(indexInBuffer, getChildCount() - 1));
int dx = (mCurrentScreen * getWidth()) - mScroller.getCurrX();
mScroller.startScroll(mScroller.getCurrX(), mScroller.getCurrY(), dx,
0, 0);
if (dx == 0)
onScrollChanged(mScroller.getCurrX() + dx, mScroller.getCurrY(), mScroller.getCurrX() + dx, mScroller.getCurrY());
if (uiThread)
invalidate();
else
postInvalidate();
}
/**
* Set the listener that will receive notifications every time the {code
* ViewFlow} scrolls.
*
* @param l the scroll listener
*/
public void setOnViewSwitchListener(ViewSwitchListener l) {
mViewSwitchListener = l;
}
@Override
public Adapter getAdapter() {
return mAdapter;
}
/**
* 适配器
* @param adapter
*/
@Override
public void setAdapter(Adapter adapter) {
setAdapter(adapter, 0);
}
public void setAdapter(Adapter adapter, int initialPosition) {
if (mAdapter != null) {
mAdapter.unregisterDataSetObserver(mDataSetObserver);
}
mAdapter = adapter;
if (mAdapter != null) {
mDataSetObserver = new AdapterDataSetObserver();
mAdapter.registerDataSetObserver(mDataSetObserver);
}
if (mAdapter == null || mAdapter.getCount() == 0)
return;
setSelection(initialPosition);
}
@Override
public View getSelectedView() {
return (mCurrentBufferIndex < mLoadedViews.size() ? mLoadedViews
.get(mCurrentBufferIndex) : null);
}
@Override
public int getSelectedItemPosition() {
return mCurrentAdapterIndex;
}
/**
* Set the FlowIndicator
*
* @param flowIndicator
*/
public void setFlowIndicator(FlowIndicator flowIndicator) {
mIndicator = flowIndicator;
mIndicator.setViewFlow(this);
}
@Override
public void setSelection(int position) {
mNextScreen = INVALID_SCREEN;
mScroller.forceFinished(true);
if (mAdapter == null)
return;
position = Math.max(position, 0);
position = Math.min(position, mAdapter.getCount() - 1);
ArrayList<View> recycleViews = new ArrayList<View>();
View recycleView;
while (!mLoadedViews.isEmpty()) {
recycleViews.add(recycleView = mLoadedViews.remove());
detachViewFromParent(recycleView);
}
View currentView = makeAndAddView(position, true,
(recycleViews.isEmpty() ? null : recycleViews.remove(0)));
mLoadedViews.addLast(currentView);
for (int offset = 1; mSideBuffer - offset >= 0; offset++) {
int leftIndex = position - offset;
int rightIndex = position + offset;
if (leftIndex >= 0)
mLoadedViews.addFirst(makeAndAddView(leftIndex, false,
(recycleViews.isEmpty() ? null : recycleViews.remove(0))));
if (rightIndex < mAdapter.getCount())
mLoadedViews.addLast(makeAndAddView(rightIndex, true,
(recycleViews.isEmpty() ? null : recycleViews.remove(0))));
}
mCurrentBufferIndex = mLoadedViews.indexOf(currentView);
mCurrentAdapterIndex = position;
for (View view : recycleViews) {
removeDetachedView(view, false);
}
requestLayout();
setVisibleView(mCurrentBufferIndex, false);
if (mIndicator != null) {
mIndicator.onSwitched(mLoadedViews.get(mCurrentBufferIndex),
mCurrentAdapterIndex);
}
if (mViewSwitchListener != null) {
mViewSwitchListener
.onSwitched(mLoadedViews.get(mCurrentBufferIndex),
mCurrentAdapterIndex);
}
}
private void resetFocus() {
mLoadedViews.clear();
removeAllViewsInLayout();
for (int i = Math.max(0, mCurrentAdapterIndex - mSideBuffer); i < Math
.min(mAdapter.getCount(), mCurrentAdapterIndex + mSideBuffer
+ 1); i++) {
mLoadedViews.addLast(makeAndAddView(i, true, null));
if (i == mCurrentAdapterIndex)
mCurrentBufferIndex = mLoadedViews.size() - 1;
}
requestLayout();
}
private void postViewSwitched(int direction) {
if (direction == 0)
return;
if (direction > 0) { // to the right
mCurrentAdapterIndex++;
mCurrentBufferIndex++;
// if(direction > 1) {
// mCurrentAdapterIndex += mAdapter.getCount() - 2;
// mCurrentBufferIndex += mAdapter.getCount() - 2;
// }
View recycleView = null;
// Remove view outside buffer range
if (mCurrentAdapterIndex > mSideBuffer) {
recycleView = mLoadedViews.removeFirst();
detachViewFromParent(recycleView);
// removeView(recycleView);
mCurrentBufferIndex--;
}
// Add new view to buffer
int newBufferIndex = mCurrentAdapterIndex + mSideBuffer;
if (newBufferIndex < mAdapter.getCount())
mLoadedViews.addLast(makeAndAddView(newBufferIndex, true,
recycleView));
} else { // to the left
mCurrentAdapterIndex--;
mCurrentBufferIndex--;
// if(direction < -1) {
// mCurrentAdapterIndex -= mAdapter.getCount() - 2;
// mCurrentBufferIndex -= mAdapter.getCount() - 2;
// }
View recycleView = null;
// Remove view outside buffer range
if (mAdapter.getCount() - 1 - mCurrentAdapterIndex > mSideBuffer) {
recycleView = mLoadedViews.removeLast();
detachViewFromParent(recycleView);
}
// Add new view to buffer
int newBufferIndex = mCurrentAdapterIndex - mSideBuffer;
if (newBufferIndex > -1) {
mLoadedViews.addFirst(makeAndAddView(newBufferIndex, false,
recycleView));
mCurrentBufferIndex++;
}
}
requestLayout();
setVisibleView(mCurrentBufferIndex, true);
if (mIndicator != null) {
mIndicator.onSwitched(mLoadedViews.get(mCurrentBufferIndex),
mCurrentAdapterIndex);
}
if (mViewSwitchListener != null) {
mViewSwitchListener
.onSwitched(mLoadedViews.get(mCurrentBufferIndex),
mCurrentAdapterIndex);
}
}
private View setupChild(View child, boolean addToEnd, boolean recycle) {
ViewGroup.LayoutParams p = (ViewGroup.LayoutParams) child
.getLayoutParams();
if (p == null) {
p = new AbsListView.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT,
ViewGroup.LayoutParams.WRAP_CONTENT, 0);
}
if (recycle)
attachViewToParent(child, (addToEnd ? -1 : 0), p);
else
addViewInLayout(child, (addToEnd ? -1 : 0), p, true);
return child;
}
private View makeAndAddView(int position, boolean addToEnd, View convertView) {
View view = mAdapter.getView(position, convertView, this);
return setupChild(view, addToEnd, convertView != null);
}
class AdapterDataSetObserver extends DataSetObserver {
@Override
public void onChanged() {
View v = getChildAt(mCurrentBufferIndex);
if (v != null) {
for (int index = 0; index < mAdapter.getCount(); index++) {
if (v.equals(mAdapter.getItem(index))) {
mCurrentAdapterIndex = index;
break;
}
}
}
resetFocus();
}
@Override
public void onInvalidated() {
// Not yet implemented!
}
}
public void setTimeSpan(long timeSpan) {
this.timeSpan = timeSpan;
}
public void setmSideBuffer(int mSideBuffer) {
this.mSideBuffer = mSideBuffer;
}
}
准备工作完成,进入主程序
- 主的xml布局文件
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.administrator.viewpagercarousel.MainActivity">
<widget.ViewFlow
android:id="@+id/viewflow"
android:layout_width="fill_parent"
android:layout_height="170dip"
/>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/viewflow"
android:layout_gravity="bottom"
android:background="@color/back"
android:gravity="center"
android:orientation="vertical"
android:padding="5dip">
<widget.CircleFlowIndicator
android:id="@+id/viewflowindic"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal|bottom"
android:layout_marginTop="3dp"
android:padding="2dip"
app:activeColor="#222"
app:activeType="fill"
app:circleSeparation="20dip"
app:inactiveColor="#ffffff"
app:inactiveType="fill"
app:radius="4dip"
/>
</LinearLayout>
</RelativeLayout>
- 主程序代码
import android.app.Activity;
import android.os.Bundle;
import java.util.ArrayList;
import java.util.List;
import adapter.FlowAdapter;
import bean.Ad;
import widget.CircleFlowIndicator;
import widget.ViewFlow;
public class MainActivity extends Activity {
private ViewFlow viewFlow;
private List<Ad> adlist;
private CircleFlowIndicator indic;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initViewpager();
}
private void initViewpager() {
//找控件
viewFlow = (ViewFlow) findViewById(R.id.viewflow);
indic = (CircleFlowIndicator) findViewById(R.id.viewflowindic);
//初始化数据
adlist = new ArrayList<Ad>();
adlist.add(new Ad(R.mipmap.b));
adlist.add(new Ad(R.mipmap.c));
adlist.add(new Ad(R.mipmap.d));
adlist.add(new Ad(R.mipmap.e));
//为viewFlow送数据
viewFlow.setAdapter(new FlowAdapter(this, adlist));
viewFlow.setmSideBuffer(adlist.size()); // 实际图片张数
viewFlow.setFlowIndicator(indic); //与圆点联动
viewFlow.setTimeSpan(4000); //自动轮播的时间
viewFlow.setSelection(3 * 1000); //设置初始位置
viewFlow.startAutoFlowTimer(); //启动自动播放
}
}
- viewFlow所需要的适配器
package adapter;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import com.example.administrator.viewpagercarousel.R;
import com.example.administrator.viewpagercarousel.StepActivity;
import java.util.List;
import bean.Ad;
/**
* viewFlow的适配器
*/
public class FlowAdapter extends BaseAdapter {
private final LayoutInflater mInflater;
private Context mContext;
private List<Ad> mAdList;
public FlowAdapter(Context context, List<Ad> adList) {
mContext = context;
mAdList = adList;
mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public int getCount() {
return Integer.MAX_VALUE; // 最大,无限循环
}
@Override
public Object getItem(int position) {
return mAdList.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
if (convertView == null) {
convertView = mInflater.inflate(R.layout.item_image, null);
}
((ImageView) convertView.findViewById(R.id.image)).setImageResource(mAdList.get(position % mAdList.size()).getImages()); //设置显示的图片
//给整张图片加监听
convertView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//跳转页面
Intent intent = new Intent(mContext, StepActivity.class);
Bundle bundle = new Bundle();
bundle.putInt("image_id", mAdList.get(position % mAdList.size()).getImages());
intent.putExtras(bundle);
mContext.startActivity(intent);
}
});
return convertView;
}
}
- 适配器需要的item布局
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:id="@+id/image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="fitXY"
android:src="@mipmap/b"
/>
</LinearLayout>