Can I use view pager with views (not with fragments)
You need to override these two methods rather than getItem():
@Override
public Object instantiateItem(ViewGroup collection, int position) {
View v = layoutInflater.inflate(...);
...
collection.addView(v,0);
return v;
}
@Override
public void destroyItem(ViewGroup collection, int position, Object view) {
collection.removeView((View) view);
}
Based on the previous answers, I made the following class to achieve that in a proper and clearest way (I hope):
public class MyViewPagerAdapter extends PagerAdapter {
ArrayList<ViewGroup> views;
LayoutInflater inflater;
public MyViewPagerAdapter(ActionBarActivity ctx){
inflater = LayoutInflater.from(ctx);
//instantiate your views list
views = new ArrayList<ViewGroup>(5);
}
/**
* To be called by onStop
* Clean the memory
*/
public void release(){
views.clear();
views = null;
}
/**
* Return the number of views available.
*/
@Override
public int getCount() {
return 5;
}
/**
* Create the page for the given position. The adapter is responsible
* for adding the view to the container given here, although it only
* must ensure this is done by the time it returns from
* {@link #finishUpdate(ViewGroup)}.
*
* @param container The containing View in which the page will be shown.
* @param position The page position to be instantiated.
* @return Returns an Object representing the new page. This does not
* need to be a View, but can be some other container of
* the page. ,container
*/
public Object instantiateItem(ViewGroup container, int position) {
ViewGroup currentView;
Log.e("MyViewPagerAdapter", "instantiateItem for " + position);
if(views.size()>position&&views.get(position) != null){
Log.e("MyViewPagerAdapter",
"instantiateItem views.get(position) " +
views.get(position));
currentView = views.get(position);
}
else{
Log.e("MyViewPagerAdapter", "instantiateItem need to create the View");
int rootLayout = R.layout.view_screen;
currentView = (ViewGroup) inflater.inflate(rootLayout, container, false);
((TextView)currentView.findViewById(R.id.txvTitle)).setText("My Views " + position);
((TextView)currentView.findViewById(R.id.btnButton)).setText("Button");
((ImageView)currentView.findViewById(R.id.imvPicture)).setBackgroundColor(0xFF00FF00);
}
container.addView(currentView);
return currentView;
}
/**
* Remove a page for the given position. The adapter is responsible
* for removing the view from its container, although it only must ensure
* this is done by the time it returns from {@link #finishUpdate(ViewGroup)}.
*
* @param container The containing View from which the page will be removed.
* @param position The page position to be removed.
* @param object The same object that was returned by
* {@link #instantiateItem(View, int)}.
*/
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View)object);
}
/**
* Determines whether a page View is associated with a specific key object
* as returned by {@link #instantiateItem(ViewGroup, int)}. This method is
* required for a PagerAdapter to function properly.
*
* @param view Page View to check for association with <code>object</code>
* @param object Object to check for association with <code>view</code>
* @return true if <code>view</code> is associated with the key object <code>object</code>
*/
@Override
public boolean isViewFromObject(View view, Object object) {
return view==((View)object);
}
}
And you have to set it in your activity:
public class ActivityWithViewsPaged extends ActionBarActivity {
/**
* The page Adapter: Manage the list of views (in fact here, its fragments)
* And send them to the ViewPager
*/
private MyViewPagerAdapter pagerAdapter;
/**
* The ViewPager is a ViewGroup that manage the swipe from left
* to right to left.
* Like a listView with a gesture listener...
*/
private ViewPager viewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_with_views);
// Find the viewPager
viewPager = (ViewPager) super.findViewById(R.id.viewpager);
// Instantiate the PageAdapter
pagerAdapter = new MyViewPagerAdapter(this);
// Affectation de l'adapter au ViewPager
viewPager.setAdapter(pagerAdapter);
viewPager.setClipToPadding(false);
viewPager.setPageMargin(12);
// Add animation when the page are swiped
// this instanciation only works with honeyComb and more
// if you want it all version use AnimatorProxy of the nineoldAndroid lib
//@see:http://stackoverflow.com/questions/15767729/backwards-compatible-pagetransformer
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB){
viewPager.setPageTransformer(true, new PageTransformer());
}
}
@Override
protected void onStop() {
super.onStop();
pagerAdapter.release();
}
Where the XML files are obvious view_screen.xml:
<xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/screen"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/txvTitle"
android:layout_width="wrap_content"
android:layout_gravity="center"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:layout_marginTop="5dp"
android:shadowColor="#FF00FF"
android:shadowDx="10"
android:shadowDy="10"
android:shadowRadius="5"
android:textSize="32dp"
android:textStyle="italic"
android:background="#FFFFF000"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#FFFF00F0">
<TextView
android:id="@+id/txvLeft"
android:layout_width="wrap_content"
android:layout_gravity="left"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:layout_marginTop="5dp"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="1"/>
<TextView
android:id="@+id/txvRight"
android:layout_width="wrap_content"
android:layout_gravity="right"
android:layout_height="wrap_content"
android:layout_marginBottom="5dp"
android:layout_marginTop="5dp"/>
</LinearLayout>
<Button
android:id="@+id/btnButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"/>
<ImageView
android:id="@+id/imvPicture"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"/>
</LinearLayout>
And ActivtyMain has the following layout:
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.view.ViewPager
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:paddingLeft="24dp"
android:paddingRight="24dp"
android:id="@+id/viewpager"
android:background="#FF00F0F0">
</android.support.v4.view.ViewPager>
Big thanks to Brian and Nicholas for your answer, I hope I add some clearest information and hightlight some good practices for this feature.
Use this example
You can use a single XML layout nesting the children views.
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.v4.view.ViewPager
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="@+id/page_one"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:text="PAGE ONE IN"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:textColor="#fff"
android:textSize="24dp"/>
</LinearLayout>
<LinearLayout
android:id="@+id/page_two"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:text="PAGE TWO IN"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:textColor="#fff"
android:textSize="24dp"/>
</LinearLayout>
</android.support.v4.view.ViewPager>
</LinearLayout>
BUT... you need handle this with an adapter also. Here we return the finded view ID without inflate any other layout.
class WizardPagerAdapter extends PagerAdapter {
public Object instantiateItem(ViewGroup collection, int position) {
int resId = 0;
switch (position) {
case 0:
resId = R.id.page_one;
break;
case 1:
resId = R.id.page_two;
break;
}
return findViewById(resId);
}
@Override
public int getCount() {
return 2;
}
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == arg1;
}
@Override public void destroyItem(ViewGroup container, int position, Object object) {
// No super
}
}
// Set the ViewPager adapter
WizardPagerAdapter adapter = new WizardPagerAdapter();
ViewPager pager = (ViewPager) findViewById(R.id.pager);
pager.setAdapter(adapter);
We have build a very simple subclass of the ViewPager that we use sometimes.
/**
* View pager used for a finite, low number of pages, where there is no need for
* optimization.
*/
public class StaticViewPager extends ViewPager {
/**
* Initialize the view.
*
* @param context
* The application context.
*/
public StaticViewPager(final Context context) {
super(context);
}
/**
* Initialize the view.
*
* @param context
* The application context.
* @param attrs
* The requested attributes.
*/
public StaticViewPager(final Context context, final AttributeSet attrs) {
super(context, attrs);
}
@Override
protected void onAttachedToWindow() {
super.onAttachedToWindow();
// Make sure all are loaded at once
final int childrenCount = getChildCount();
setOffscreenPageLimit(childrenCount - 1);
// Attach the adapter
setAdapter(new PagerAdapter() {
@Override
public Object instantiateItem(final ViewGroup container, final int position) {
return container.getChildAt(position);
}
@Override
public boolean isViewFromObject(final View arg0, final Object arg1) {
return arg0 == arg1;
}
@Override
public int getCount() {
return childrenCount;
}
@Override
public void destroyItem(final View container, final int position, final Object object) {}
});
}
}
This class does not need a adapter as it will load the views from the layout. In order to use it your projects, just use it instead of the android.support.v4.view.ViewPager.
All the fancy stuff will still work, but you do not need to be bothered with the adapters.