Develop Reference

PageAdapter + VerticalViewPager NOT working Together. Why?

I'm trying to figure out why my images within class CustomPagerAdapter mResources are NOT showing up once the VerticalViewPager widget appears -- nothing on start and nothing during vertical swipe.
I've been at it for a couple days but just cant crack it. Doesnt help the documentation on ViewPager / Adapters isnt very clear.
Using - Nexus 6 AVD, minSdkVersion = 19
When i attempt to scroll up (single click from the bottom and swipe up all the way to the top) i then receive this error message...
*AndroidRuntime: FATAL EXCEPTION: main
Process: sparktic.com.verticalviewpager, PID: 19242
java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
at android.view.ViewGroup.addViewInner(ViewGroup.java:3562)*
AFAIK i'm adding and removing pager_item correctly.
java/ MainActivity.java
package sparktic.com.verticalviewpager;
import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
public class MainActivity extends AppCompatActivity
{
VerticalViewPager mPager;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mPager = findViewById(R.id.viewpager);
CustomPagerAdapter adapter = new CustomPagerAdapter(this);
mPager.setAdapter(adapter);
}
class CustomPagerAdapter extends PagerAdapter
{
Context mContext;
public LayoutInflater mLayoutInflater;
int[] mResources = {
R.drawable.first, // Dload: https://i.imgur.com/suvAa9x.jpg
R.drawable.second, // Dload: https://i.imgur.com/c2f0Hvy.jpg
R.drawable.third // Dload: https://i.imgur.com/0GAs8qp.jpg
};
public CustomPagerAdapter(Context context)
{
mContext = context;
mLayoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
#Override
public int getCount()
{
return mResources.length;
}
#Override
public boolean isViewFromObject(View view, Object object)
{
return view == ((LinearLayout) object);
}
#Override
public Object instantiateItem(ViewGroup container, int position)
{
View itemView = mLayoutInflater.inflate(R.layout.pager_item, container, false);
ImageView imageView = (ImageView) itemView.findViewById(R.id.imageView);
imageView.setImageResource(mResources[position]);
container.addView(imageView);
return itemView;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object)
{
container.removeView((LinearLayout) object);
}
}
}
layout/ activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="sparktic.com.verticalviewpager.MainActivity">
<sparktic.com.verticalviewpager.VerticalViewPager
android:id="#+id/viewpager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
layout/ pager_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/imageView" />
</LinearLayout>
java/ VerticalViewPager.java
package sparktic.com.verticalviewpager;
import android.content.Context;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
public class VerticalViewPager extends ViewPager
{
public VerticalViewPager(Context context)
{
this(context, null);
}
public VerticalViewPager(Context context, AttributeSet attrs)
{
super(context, attrs);
init();
}
#Override
public boolean canScrollHorizontally(int direction)
{
return false;
}
#Override
public boolean canScrollVertically(int direction)
{
return super.canScrollHorizontally(direction);
}
private void init()
{
setPageTransformer(true, new VerticalPageTransformer());
setOverScrollMode(View.OVER_SCROLL_NEVER);
}
#Override
public boolean onInterceptTouchEvent(MotionEvent ev)
{
final boolean toIntercept = super.onInterceptTouchEvent(flipXY(ev));
flipXY(ev);
return toIntercept;
}
#Override
public boolean onTouchEvent(MotionEvent ev)
{
final boolean toHandle = super.onTouchEvent(flipXY(ev));
flipXY(ev);
return toHandle;
}
private MotionEvent flipXY(MotionEvent ev)
{
final float width = getWidth();
final float height = getHeight();
final float x = (ev.getY() / height) * width;
final float y = (ev.getX() / width) * height;
ev.setLocation(x, y);
return ev;
}
private static final class VerticalPageTransformer implements ViewPager.PageTransformer
{
#Override
public void transformPage(View view, float position)
{
final int pageWidth = view.getWidth();
final int pageHeight = view.getHeight();
if (position < -1)
{
view.setAlpha(0);
}
else if (position <= 1)
{
view.setAlpha(1);
view.setTranslationX(pageWidth * -position);
float yPosition = position * pageHeight;
view.setTranslationY(yPosition);
}
else
{
view.setAlpha(0);
}
}
}
}

Solved my own problem. In case it helps someone else...
the issue was within "instantiateItem" method.
container.addView(imageView); should have been container.addView(itemView);
I still dont have a solid grasp as to what is happening within the PageAdapter overrides but it works so i'll take the win and move on.

VideoView disappearing while scrolling/swiping in VerticalViewPager

I am having an issue with VideoView when using with VerticalViewPager.
When I scroll/swipe the ViewPager the VideoView becomes black. Actually here VideoView is getting disappeared the black color is the background of the ViewPager.
I don't have this issue when using horizontal ViewPager even with current custom VerticalViewpager set to horizontal.
When I scroll, VideoView disappears and when I lift my finger from screen VideoView appears back again.
I have tried many VerticalViewpager libraries and almost all of them have this same issue.
Have anyone faced this issue before? How to fix this?
These are the screenshots:
VideoView when not swiping:
VideoView when swiping vertically:
Here is my code
VerticalViewpager.java
import android.content.Context;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
public class VerticalViewpager extends ViewPager {
public VerticalViewpager(Context context) {
super(context);
init();
}
public VerticalViewpager(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init() {
// The majority of the magic happens here
setPageTransformer(true, new VerticalPageTransformer());
// The easiest way to get rid of the overscroll drawing that happens on the left and right
setOverScrollMode(OVER_SCROLL_NEVER);
}
private class VerticalPageTransformer implements ViewPager.PageTransformer {
#Override
public void transformPage(View view, float position) {
if (position < -1) { // [-Infinity,-1)
// This page is way off-screen to the left.
view.setAlpha(0);
} else if (position <= 1) { // [-1,1]
view.setAlpha(1);
// Counteract the default slide transition
view.setTranslationX(view.getWidth() * -position);
//set Y position to swipe in from top
float yPosition = position * view.getHeight();
view.setTranslationY(yPosition);
} else { // (1,+Infinity]
// This page is way off-screen to the right.
view.setAlpha(0);
}
}
}
/**
* Swaps the X and Y coordinates of your touch event.
*/
private MotionEvent swapXY(MotionEvent ev) {
float width = getWidth();
float height = getHeight();
float newX = (ev.getY() / height) * width;
float newY = (ev.getX() / width) * height;
ev.setLocation(newX, newY);
return ev;
}
#Override
public boolean onInterceptTouchEvent(MotionEvent ev){
boolean intercepted = super.onInterceptTouchEvent(swapXY(ev));
swapXY(ev); // return touch coordinates to original reference frame for any child views
return intercepted;
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
return super.onTouchEvent(swapXY(ev));
}
}
MainActivity.java
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentStatePagerAdapter;
import android.support.v7.app.AppCompatActivity;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
MyPagerAdapter adapterViewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
VerticalViewpager vpPager = (VerticalViewpager) findViewById(R.id.vpPAger);
adapterViewPager = new MyPagerAdapter(getSupportFragmentManager());
vpPager.setAdapter(adapterViewPager);
for (int i = 0; i < 2; i++) {
adapterViewPager.addFragment(FragmentWithOneImage.newInstance("Frag "+ i,R.drawable.jackie));
}
vpPager.setAdapter(adapterViewPager);
}
public static class MyPagerAdapter extends FragmentStatePagerAdapter {
private final List<Fragment> mFragments = new ArrayList<>();
public MyPagerAdapter(FragmentManager fm) {
super(fm);
}
public void addFragment(Fragment fragment) {
mFragments.add(fragment);
}
#Override
public Fragment getItem(int position) {
return mFragments.get(position);
}
#Override
public int getCount() {
return mFragments.size();
}
#Override
public float getPageWidth(int position) {
return super.getPageWidth(position);
}
}
}
FragmentWithOneImage.java
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.VideoView;
public class FragmentWithOneImage extends Fragment {
private String title;
private int image;
public static FragmentWithOneImage newInstance(String title, int resImage) {
FragmentWithOneImage fragment = new FragmentWithOneImage();
Bundle args = new Bundle();
args.putInt("image", resImage);
args.putString("title", title);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
image = getArguments().getInt("image", 0);
title = getArguments().getString("title");
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_one_img, container, false);
ImageView imageView = (ImageView) view.findViewById(R.id.imgMain);
imageView.setImageResource(image);
Uri uri = Uri.parse("http://abhiandroid-8fb4.kxcdn.com/ui/wp-content/uploads/2016/04/videoviewtestingvideo.mp4");
VideoView simpleVideoView = (VideoView) view.findViewById(R.id.simpleVideoView); // initiate a video view
simpleVideoView.setVideoURI(uri);
simpleVideoView.start();
return view;
}
#Override
public void onResume() {
super.onResume();
}
}
activiy_main.xml
<?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">
<com.example.sudheeshm.verticalviewpager.VerticalViewpager
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/vpPAger"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:swipe_orientation="vertical"
android:background="#android:color/black"/>
</LinearLayout>
fragment_one_img.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/white"
>
<VideoView
android:id="#+id/simpleVideoView"
android:layout_width="match_parent"
android:layout_height="300dp" />
<ImageView
android:layout_below="#+id/simpleVideoView"
android:id="#+id/imgMain"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>
attrs.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="VerticalViewpager" >
<attr name="swipe_orientation" format="enum" >
<enum name="horizontal" value="0" />
<enum name="vertical" value="1" />
</attr>
</declare-styleable>
</resources>

It has to do with VideoView being based on SurfaceView and this view is not optimized for tranlations (scrolling in a ViewPager). Check out these answers related to VideoViews in a ViewPager at these following links: post 1, 2.
Maybe you can find a solution to your issue.

Android : ViewPager with a dynamic height within a ScrollView

I have a ScrollView which hosts a ViewPager which hosts Fragments of dynamic height. Since a ScrollView and ViewPager don't go well together due to the scroll handling, I used one of the custom solution from here. But I am currently getting really abnormal results. The first fragment in the ViewPager always gets a height of 0. Also sometimes the fragments don't show their content but when I scroll back and forth and come back to that fragment, content might show up.
Some code for you to look at :
The custom ViewPager :
import android.content.Context;
import android.support.v4.view.ViewPager;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
/**
* Created by Narayan Acharya on 12/07/2016.
*/
public class DynamicHeightWrappingViewPager extends ViewPager {
private View mCurrentView;
public DynamicHeightWrappingViewPager(Context context) {
super(context);
}
public DynamicHeightWrappingViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
if (mCurrentView == null) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
return;
}
int height = 0;
mCurrentView.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
int h = mCurrentView.getMeasuredHeight();
if (h > height) height = h;
heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
Log.d("ViewPager Measure", h + ":" + heightMeasureSpec);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
public void measureCurrentView(View currentView) {
mCurrentView = currentView;
requestLayout();
}
}
The custom ScrollView :
import android.content.Context;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.widget.ScrollView;
/**
* Created by Narayan Acharya on 12/07/2016.
*/
public class ChildrenHeightAdaptingScrollView extends ScrollView {
private GestureDetector mGestureDetector;
public ChildrenHeightAdaptingScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
mGestureDetector = new GestureDetector(context, new YScrollDetector());
setFadingEdgeLength(0);
}
#Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
return super.onInterceptTouchEvent(ev)
&& mGestureDetector.onTouchEvent(ev);
}
// Return false if we're scrolling in the x direction
class YScrollDetector extends GestureDetector.SimpleOnGestureListener {
#Override
public boolean onScroll(MotionEvent e1, MotionEvent e2,
float distanceX, float distanceY) {
return (Math.abs(distanceY) > Math.abs(distanceX));
}
}
}
The PagerAdapter :
import android.app.Fragment;
import android.app.FragmentManager;
import android.support.v13.app.FragmentPagerAdapter;
import android.util.Log;
import android.view.ViewGroup;
/.. Some more project specific imports here../
/**
* Created by Narayan Acharya on 22/06/2016.
*/
public class EventsPagerAdapter extends FragmentPagerAdapter {
private Event event;
private int PAGE_COUNT = 2;
private int mCurrentPosition = -1;
private String tabTitles[] = new String[]{"INFO", "FAQs"};
public EventsPagerAdapter(FragmentManager fm, Event event) {
super(fm);
this.event = event;
}
#Override
public Fragment getItem(int position) {
switch (position) {
case 0:
return EventInfoFragment.getInstance(event);
case 1:
return EventFAQsFragment.getInstance(event);
default:
return null;
}
}
#Override
public int getCount() {
return PAGE_COUNT;
}
#Override
public CharSequence getPageTitle(int position) {
// Generate title based on item position
return tabTitles[position];
}
#Override
public void setPrimaryItem(ViewGroup container, int position, Object object) {
super.setPrimaryItem(container, position, object);
if (position != mCurrentPosition) {
Fragment fragment = (Fragment) object;
DynamicHeightWrappingViewPager pager = (DynamicHeightWrappingViewPager) container;
if (fragment != null && fragment.getView() != null) {
mCurrentPosition = position;
pager.measureCurrentView(fragment.getView());
Log.d("Requested Measure for", position + " " + fragment.getClass().getSimpleName());
}
}
}
}
As per my observations, the only difference I could spot in the code from the link I mentioned above and the one I am using is that the link uses FragmentPagerAdapter from support library v4 while I am using from the v13(Cannot change this to v4, due to some other restrictions). What are the major differences between the two versions of support library for how I am using it?

This might seem like really stupid and I am not sure why this works exactly! If anyone knows why, please do answer.
The problem with the ViewPager collapsing was that it simply contained a WebView in each Fragment. I toiled hard trying to find solutions and writing more custom ViewPagers and ScrollViews. Just when I was about to give up I wrapped the WebView in a LinearLayout and the Fragment at position 0 did not collapse. It works smoothly now.
So if anyone is getting blank pages while trying this or similar solutions please try to wrap it in a LinearLayout or something.
Hope this helps someone!

Can't create a View Pager

I want to create a ViewPager, but when I execute the application in my phone, it shows me a blank activity and then the following error message:
The application testViewPager (process com.example.testviewpager) has stopped unexpectedly. Please try again.
How can I go about fixing this problem?
Main.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent">
<com.example.testviewpager.PagerContainer
android:id="#+id/pager_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#CCC">
<android.support.v4.view.ViewPager
android:layout_width="150dp"
android:layout_height="100dp"
android:layout_gravity="center_horizontal" />
</com.example.testviewpager.PagerContainer>
</RelativeLayout>
PagerActivity.java:
public class PagerActivity extends Activity {
PagerContainer mContainer;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mContainer = (PagerContainer) findViewById(R.id.pager_container);
ViewPager pager = mContainer.getViewPager();
PagerAdapter adapter = new MyPagerAdapter();
pager.setAdapter(adapter);
//Necessary or the pager will only have one extra page to show
// make this at least however many pages you can see
pager.setOffscreenPageLimit(adapter.getCount());
//A little space between pages
pager.setPageMargin(15);
//If hardware acceleration is enabled, you should also remove
// clipping on the pager for its children.
pager.setClipChildren(false);
}
//Nothing special about this adapter, just throwing up colored views for demo
private class MyPagerAdapter extends PagerAdapter {
#Override
public Object instantiateItem(ViewGroup container, int position) {
TextView view = new TextView(PagerActivity.this);
view.setText("Item "+position);
view.setGravity(Gravity.CENTER);
view.setBackgroundColor(Color.argb(255, position * 50, position * 10, position * 50));
container.addView(view);
return view;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View)object);
}
#Override
public int getCount() {
return 5;
}
#Override
public boolean isViewFromObject(View view, Object object) {
return (view == object);
}
}
}
PagerContainer.java:
public class PagerContainer extends FrameLayout implements ViewPager.OnPageChangeListener {
private ViewPager mPager;
boolean mNeedsRedraw = false;
public PagerContainer(Context context) {
super(context);
init();
}
public PagerContainer(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public PagerContainer(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
private void init() {
setClipChildren(false);
}
#Override
protected void onFinishInflate() {
try {
mPager = (ViewPager) getChildAt(0);
mPager.setOnPageChangeListener(this);
} catch (Exception e) {
throw new IllegalStateException("The root child of PagerContainer must be a ViewPager");
}
}
public ViewPager getViewPager() {
return mPager;
}
private Point mCenter = new Point();
private Point mInitialTouch = new Point();
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
mCenter.x = w / 2;
mCenter.y = h / 2;
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
//We capture any touches not already handled by the ViewPager
// to implement scrolling from a touch outside the pager bounds.
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
mInitialTouch.x = (int)ev.getX();
mInitialTouch.y = (int)ev.getY();
default:
ev.offsetLocation(mCenter.x - mInitialTouch.x, mCenter.y - mInitialTouch.y);
break;
}
return mPager.dispatchTouchEvent(ev);
}
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
//Force the container to redraw on scrolling.
//Without this the outer pages render initially and then stay static
if (mNeedsRedraw) invalidate();
}
#Override
public void onPageSelected(int position) { }
#Override
public void onPageScrollStateChanged(int state) {
mNeedsRedraw = (state != ViewPager.SCROLL_STATE_IDLE);
}
}
MainActivity.java:
public class MainActivity extends Activity
{
PagerContainer mContainer;
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mContainer = (PagerContainer) findViewById(R.id.pager_container);
ViewPager pager = mContainer.getViewPager();
PagerAdapter adapter = new MyPagerAdapter();
pager.setAdapter(adapter);
// Necessary or the pager will only have one extra page to show
// make this at least however many pages you can see
pager.setOffscreenPageLimit(adapter.getCount());
// A little space between pages
pager.setPageMargin(15);
}
// Nothing special about this adapter, just throwing up colored views for
// demo
private class MyPagerAdapter extends PagerAdapter
{
#Override
public Object instantiateItem(ViewGroup container, int position)
{
TextView view = new TextView(MainActivity.this);
view.setText("Item " + position);
view.setGravity(Gravity.CENTER);
view.setBackgroundColor(Color.argb(255, position * 50,
position * 10, position * 50));
container.addView(view);
return view;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object)
{
container.removeView((View) object);
}
#Override
public int getCount()
{
return 5;
}
#Override
public boolean isViewFromObject(View view, Object object)
{
return (view == object);
}
}
}

How to do Horizontal scroll view with images scroll in two directions

I am trying to show horizontal scroll view with images to scroll in two directions.Previously for this i used Gallery View but galleryview is deprected ,i am using horizontal scroll view instead of gallery view but horizontal scroll view is different with gallery view.
Now i have to do two implementation
1) Scrolling in two directions continuously.
2) Center lock feature as same as gallery.
My screen looks like

you can use viewpager,
try this code and modify it as your need .
note : this not my code already found it on the net belong to:
( Dave Smith,#devunwired Date: 8/17/12 PagerActivity).
MainActivity:
public class MainActivity extends Activity{
PagerContainer mContainer;
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mContainer = (PagerContainer) findViewById(R.id.pager_container);
ViewPager pager = mContainer.getViewPager();
PagerAdapter adapter = new MyPagerAdapter();
pager.setAdapter(adapter);
// Necessary or the pager will only have one extra page to show
// make this at least however many pages you can see
pager.setOffscreenPageLimit(adapter.getCount());
// A little space between pages
pager.setPageMargin(15);}
// Nothing special about this adapter, just throwing up colored views for
// demo
private class MyPagerAdapter extends PagerAdapter{
#Override
public Object instantiateItem(ViewGroup container, int position){
TextView view = new TextView(MainActivity.this);
view.setText("Item " + position);
view.setGravity(Gravity.CENTER);
view.setBackgroundColor(Color.argb(255, position * 50,
position * 10, position * 50));
container.addView(view);
return view;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object)
{
container.removeView((View) object);}
#Override
public int getCount(){
return 5;
}
#Override
public boolean isViewFromObject(View view, Object object)
{
return (view == object);
}}}
PagerContainer:
public class PagerContainer extends FrameLayout implements
ViewPager.OnPageChangeListener {
private ViewPager mPager;
boolean mNeedsRedraw = false;
public PagerContainer(Context context) {
super(context);
init();
}
public PagerContainer(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public PagerContainer(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
private void init() {
setClipChildren(false);
}
#Override
protected void onFinishInflate() {
try {
mPager = (ViewPager) getChildAt(0);
mPager.setOnPageChangeListener(this);
} catch (Exception e) {
throw new IllegalStateException("The root child of PagerContainer must be a
ViewPager");
}
}
public ViewPager getViewPager() {
return mPager;
}
private Point mCenter = new Point();
private Point mInitialTouch = new Point();
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
mCenter.x = w / 2;
mCenter.y = h / 2;
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
//We capture any touches not already handled by the ViewPager
// to implement scrolling from a touch outside the pager bounds.
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
mInitialTouch.x = (int)ev.getX();
mInitialTouch.y = (int)ev.getY();
default:
ev.offsetLocation(mCenter.x - mInitialTouch.x, mCenter.y -
mInitialTouch.y);
break;
}
return mPager.dispatchTouchEvent(ev);
}
public void onPageScrolled(int position, float positionOffset, int
positionOffsetPixels) {
//Force the container to redraw on scrolling.
//Without this the outer pages render initially and then stay static
if (mNeedsRedraw) invalidate();
}
public void onPageSelected(int position) { }
public void onPageScrollStateChanged(int state) {
mNeedsRedraw = (state != ViewPager.SCROLL_STATE_IDLE);
}
}
activity_main.xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<com.example.testviewpager.PagerContainer
android:id="#+id/pager_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#CCC" >
<android.support.v4.view.ViewPager
android:layout_width="150dp"
android:layout_height="100dp"
android:layout_gravity="center_horizontal" />
</com.example.testviewpager.PagerContainer>
</RelativeLayout>
hope help you.