Develop Reference

Viewpager page not expanding on button click

I have a page in viewpager which have a button and a few views which are hidden by default. On click of the button, the views are to be toggled(Show/Hide). My issue is button click is working, but viewpager's height does not changes.
This is the code for adapter:
public class HomeCategoryAdapter extends PagerAdapter implements View.OnClickListener {
private LayoutInflater inflater;
private View lin_view_more, lin_view_less, lin_view_1, lin_view_2, lin_view_3, lin_view_4;
private WrapContentViewPager pager;
public HomeCategoryAdapter(Context context) {
this.mContext = context;
this.inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
#Override
public int getCount() {
return 5;
}
#Override
public int getItemPosition(Object object) {
return super.getItemPosition(object);
}
#Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == arg1;
}
#Override
public Object instantiateItem(final ViewGroup container, final int position) {
pager = (EnhancedWrapContentViewPager) container;
View itemView = inflater.inflate(R.layout.homescreen_category_adapter, container, false);
...
lin_view_more = itemView.findViewById(R.id.lin_view_more);
lin_view_more.setOnClickListener(this);
lin_view_1 = itemView.findViewById(R.id.lin_view_1);
lin_view_1.setOnClickListener(this);
lin_view_2 = itemView.findViewById(R.id.lin_view_2);
lin_view_2.setOnClickListener(this);
lin_view_3 = itemView.findViewById(R.id.lin_view_3);
lin_view_3.setOnClickListener(this);
lin_view_4 = itemView.findViewById(R.id.lin_view_4);
lin_view_4.setOnClickListener(this);
switch (position) {
case 0:
parent_1.setVisibility(View.VISIBLE);
parent_2.setVisibility(View.GONE);
parent_3.setVisibility(View.GONE);
parent_4.setVisibility(View.GONE);
parent_5.setVisibility(View.GONE);
break;
case 1:
parent_1.setVisibility(View.GONE);
parent_2.setVisibility(View.VISIBLE);
parent_3.setVisibility(View.GONE);
parent_4.setVisibility(View.GONE);
parent_5.setVisibility(View.GONE);
break;
case 2:
parent_1.setVisibility(View.GONE);
parent_2.setVisibility(View.GONE);
parent_3.setVisibility(View.VISIBLE);
parent_4.setVisibility(View.GONE);
parent_5.setVisibility(View.GONE);
break;
case 3:
parent_1.setVisibility(View.GONE);
parent_2.setVisibility(View.GONE);
parent_3.setVisibility(View.GONE);
parent_4.setVisibility(View.VISIBLE);
parent_5.setVisibility(View.GONE);
break;
case 4:
parent_1.setVisibility(View.GONE);
parent_2.setVisibility(View.GONE);
parent_3.setVisibility(View.GONE);
parent_4.setVisibility(View.GONE);
parent_5.setVisibility(View.VISIBLE);
break;
}
...
((WrapContentViewPager) container).addView(itemView);
return itemView;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
((WrapContentViewPager) container).removeView((View) object);
}
#Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.lin_view_more:
lin_view_more.setVisibility(View.GONE);
lin_view_1.setVisibility(View.VISIBLE);
lin_view_2.setVisibility(View.VISIBLE);
lin_view_3.setVisibility(View.VISIBLE);
lin_view_4.setVisibility(View.VISIBLE);
lin_view_less.setVisibility(View.VISIBLE);
if (pager != null) {
pager.measureView();
}
break;
case R.id.lin_view_less:
lin_view_more.setVisibility(View.VISIBLE);
lin_view_1.setVisibility(View.GONE);
lin_view_2.setVisibility(View.GONE);
lin_view_3.setVisibility(View.GONE);
lin_view_4.setVisibility(View.GONE);
lin_view_less.setVisibility(View.GONE);
if (pager != null) {
pager.post(new Runnable() {
#Override
public void run() {
pager.measureView();
}
});
}
break;
}
}
}
This is the code for modified view pager to make it wrap_content:
public class WrapContentViewPager extends ViewPager {
public WrapContentViewPager (Context context) {
super(context);
}
public WrapContentViewPager (Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int mode = MeasureSpec.getMode(heightMeasureSpec);
if (mode == MeasureSpec.UNSPECIFIED || mode == MeasureSpec.AT_MOST) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int height = 0;
for (int i = 0; i < getChildCount(); i++) {
View child = getChildAt(i);
child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
int childMeasuredHeight = child.getMeasuredHeight();
if (childMeasuredHeight > height) {
Log.debugMessage("WrapContentViewPager", "page height updated");
height = childMeasuredHeight;
}
}
heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
}
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
public void measureView(){
requestLayout();
}
}
As shown in onClick above, I am calling requestLayout() on pager. The page height gets calculated but the layout is not expanding.
Update:
If I swipe to another page(3rd or 4th) then go back to this page, show/hide are working fine.
Not getting why is it not working.

Can you add this code after requestLayout();code line:
invalidate();
if it doesn't work also can you try this:
postInvalidate();
For what these code lines do, you can take a look at this:
What does postInvalidate() do?

Is it possible to have a viewpager wrap_content on a simple pager adapter without children

I would like to know if is it possible to have a PagerAdapter with wrap_content without using getChildCount() and getChildAt(i)?
I have checked the answer below, but since on my adapter doesn't have children it doesn't work.
https://stackoverflow.com/a/20784791/10020799
Does someone know how to make an wrap_content adapter in this case?
My PagerAdapter code is:
public class SectionsPagerAdapter extends PagerAdapter {
private Integer pagerTotal = 10;
public SectionsPagerAdapter(Context c) {
super();
inflater = (LayoutInflater) c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public void setPagerTotal(Integer item) {
pagerTotal = item;
}
#Override
public int getCount() {
return pagerTotal;
}
#Override
public Object instantiateItem(ViewGroup container, int position) {
LinearLayout layout = (LinearLayout) inflater.inflate(R.layout.home_top_page, null);
container.addView(layout);
topMain = (ImageView) layout.findViewById(R.id.top_main);
if(imageBitmapArray != null && imageBitmapArray.length > 0){
topMain.setImageBitmap(imageBitmapArray[position]);
}else{
if(intImageArray != null) {
topMain.setImageResource(R.drawable.top_main_01);
}
}
return layout;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
((ViewPager) container).removeView((View) object);
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view.equals(object);
}
}

You can resize the ViewPager to it's current page size on page swipe from this answer.
You can use the following code:
public class WrapContentViewPager extends ViewPager {
private int mCurrentPagePosition = 0;
public WrapContentViewPager(Context context) {
super(context);
}
public WrapContentViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
try {
boolean wrapHeight = MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST;
if (wrapHeight) {
View child = getChildAt(mCurrentPagePosition);
if (child != null) {
child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
int h = child.getMeasuredHeight();
heightMeasureSpec = MeasureSpec.makeMeasureSpec(h, MeasureSpec.EXACTLY);
}
}
} catch (Exception e) {
e.printStackTrace();
}
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
public void reMeasureCurrentPage(int position) {
mCurrentPagePosition = position;
requestLayout();
}
}
Use it in xml:
<your.package.name.WrapContentViewPager
android:id="#+id/view_pager"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</your.package.name.WrapContentViewPager>
After that call reMeasureCurrentpage function on page swipe.
final WrapContentViewPager wrapContentViewPager = (WrapContentViewPager) findViewById(R.id.view_pager);
wrapContentViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
wrapContentViewPager.reMeasureCurrentPage(wrapContentViewPager.getCurrentItem());
}
#Override
public void onPageScrollStateChanged(int state) {
}
});
Note that a list can have hundreds of items then this is not good to use this wrap_content ViewPager.

Even with a not expandable adapter is possible to use getChildCount() and getChildAt(i) functions.
Based on Khemraj's answer and this post's answer, I was able to solve the problem with the following code:
class:
public class WrapContentViewPager extends ViewPager {
public WrapContentViewPager(Context context) {
super(context);
}
public WrapContentViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int height = 0;
for(int i = 0; i < getChildCount(); i++) {
View child = getChildAt(i);
child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
int h = child.getMeasuredHeight();
if(h > height) height = h;
}
if (height != 0) {
heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
}
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
xml:
<your.package.name.WrapContentViewPager
android:id="#+id/view_pager"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</your.package.name.WrapContentViewPager>
on page swipe:
final WrapContentViewPager wrapContentViewPager = (WrapContentViewPager) findViewById(R.id.view_pager);
wrapContentViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
}
#Override
public void onPageScrollStateChanged(int state) {
}
});

How to set dynamic height to view pager child fragments in android?

I am having view pager with 4 different fragments. In this, 3 fragments only contains webview. All the fragments load different contents. I unable to set a height based on the loaded content. For that, I wrote a custom viewpager to measure height of viewpager. For the first viewpager fragment, height is calculated properly. But when navigate to second or third fragment, viewpager height is not calculated accurately. I don't know, what is the issue is in my code and what i need to change to calculate proper height for each fragment after navigate to that view pager page. Here is my view pager and pager adapter codes. Kindly help me.
Custom View pager:
public class CustomViewPager extends ViewPager {
public CustomViewPager (Context context) {
super(context);
}
public CustomViewPager (Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
boolean wrapHeight = MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST;
final View tab = getChildAt(0);
int width = getMeasuredWidth();
int tabHeight = tab.getMeasuredHeight();
if (wrapHeight) {
// Keep the current measured width.
widthMeasureSpec = MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY);
}
int fragmentHeight = measureFragment(((Fragment) getAdapter().instantiateItem(this, getCurrentItem())).getView());
heightMeasureSpec = MeasureSpec.makeMeasureSpec(tabHeight + fragmentHeight + (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 50, getResources().getDisplayMetrics()), MeasureSpec.AT_MOST);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
#Override
public void setOnPageChangeListener(OnPageChangeListener listener) {
requestLayout();
invalidate();
super.setOnPageChangeListener(listener);
}
#Override
public void addOnPageChangeListener(OnPageChangeListener listener) {
super.addOnPageChangeListener(listener);
}
public int measureFragment(View view) {
if (view == null)
return 0;
view.measure(0, 0);
return view.getMeasuredHeight();
}
}
PagerAdapter:
public class MerchantsCataAdapter extends FragmentPagerAdapter {
Context context;
Merchant merchant;
Fragment fragment;
private int mCurrentPosition = -1;
private String[] tabs = {"Home", "About Us","Promotions","Store Information"};
public MerchantsCataAdapter(FragmentManager fm, Context context,Merchant merchant) {
super(fm);
this.context = context;
this.merchant = merchant;
}
#Override
public Fragment getItem(int index) {
switch (index) {
case 0:
fragment= new HomeContentFragment().newInstance(merchant.getCompany_home_content(),merchant.getVideo_url());
break;
case 1:
fragment= new AboutusFragment().newInstance(merchant.getFull_description(),merchant.getVideo_url());
break;
case 2:
fragment= new AboutusFragment().newInstance(merchant.getCompany_promotions(),merchant.getVideo_url());
break;
case 3:
fragment= new FragmentStoreInformation().newInstance(merchant.getMerchantId(),merchant.getName());
break;
}
return fragment;
}
#Override
public int getCount() {
return tabs.length;
}
public String getTabView(int position) {
return tabs[position];
}

Finally, I find the answer. Place below property in Webview in xml. This will take webview height automatically based on the content.
android:scrollbarStyle="insideOverlay"

How to invalidate view after it changed?

Please see this example img below first.
Sorry, my reputation is not enough, click below to see gif please
example img
Just as you see, i am using horizontalscrollview in bottom area. I can not scroll it to border when it become bigger. I can not figure out why, hope someone can help me solve this problem.
public class Rebound extends HorizontalScrollView implements View.OnClickListener {
private LinearLayout container;
private HorizontalScrollViewAdapter adapter;
private int childWidth, childHeight;
private CurrentImageChangeListener listener;
private OnItemClickListener onClickListener;
public Rebound(Context context, AttributeSet attrs) {
super(context);
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
container = (LinearLayout) getChildAt(0);
}
#Override
public void invalidate() {
super.invalidate();
}
public void initDatas(HorizontalScrollViewAdapter adapter) {
this.adapter = adapter;
container = (LinearLayout) getChildAt(0);
final View view = adapter.getView(0, null, container);
container.addView(view);
calculateChildView(view);
}
private void calculateChildView(View view) {
if (childWidth == 0 && childHeight == 0) {
int w = View.MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
int h = View.MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
view.measure(w, h);
childHeight = view.getMeasuredHeight();
childWidth = view.getMeasuredWidth();
}
initChild();
}
private void initChild() {
container = (LinearLayout) getChildAt(0);
container.removeAllViews();
for (int i = 0; i < adapter.getCount(); i++) {
View view = adapter.getView(i, null, container);
view.setOnClickListener(this);
container.addView(view);
}
}
#Override
public void onClick(View v) {
}
public interface CurrentImageChangeListener {
void onCurrentImgChanged(int position, View viewIndicator);
}
public interface OnItemClickListener {
void onClick(View view, int pos);
}
public void setOnItemClickListener(OnItemClickListener onClickListener) {
this.onClickListener = onClickListener;
}
public void setCurrentImageChangeListener(CurrentImageChangeListener listener) {
this.listener = listener;
}
}

Dynamic height viewpager

I'm trying to create a custom viewpager inside custom scroll viewthat dynamically wraps the current child's height.
package com.example.vihaan.dynamicviewpager;
import android.content.Context;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.widget.ScrollView;
/**
* Created by vihaan on 1/9/15.
*/
public class CustomScrollView extends ScrollView {
private GestureDetector mGestureDetector;
public CustomScrollView(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));
}
}
}
CustomPager
/**
* Created by vihaan on 1/9/15.
*/
public class CustomPager extends ViewPager {
public CustomPager (Context context) {
super(context);
}
public CustomPager (Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
boolean wrapHeight = MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST;
final View tab = getChildAt(0);
int width = getMeasuredWidth();
int tabHeight = tab.getMeasuredHeight();
if (wrapHeight) {
// Keep the current measured width.
widthMeasureSpec = MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY);
}
int fragmentHeight = measureFragment(((Fragment) getAdapter().instantiateItem(this, getCurrentItem())).getView());
heightMeasureSpec = MeasureSpec.makeMeasureSpec(tabHeight + fragmentHeight + (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 50, getResources().getDisplayMetrics()), MeasureSpec.AT_MOST);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
public int measureFragment(View view) {
if (view == null)
return 0;
view.measure(0, 0);
return view.getMeasuredHeight();
}
}
MyPagerAdapter
public class MyPagerAdapter extends FragmentPagerAdapter {
private List<Fragment> fragments;
public MyPagerAdapter(FragmentManager fm) {
super(fm);
this.fragments = new ArrayList<Fragment>();
fragments.add(new FirstFragment());
fragments.add(new SecondFragment());
fragments.add(new ThirdFragment());
fragments.add(new FourthFragment());
}
#Override
public Fragment getItem(int position) {
return fragments.get(position);
}
#Override
public int getCount() {
return fragments.size();
}
}
I was hoping that this would wrap around current fragments height but it is only taking the height of first child into consideration.
Sample github project : https://github.com/VihaanVerma89/DynamicViewPager

Made a few tweaks in your code and it is working fine now.
1] onMeasure function wasn't proper. Use below logic
#Override
public 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);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
2] ViewPager needs to be re-measured each time a page is changed. Good place to do this is setPrimaryItem function of PagerAdapter
#Override
public void setPrimaryItem(ViewGroup container, int position, Object object) {
super.setPrimaryItem(container, position, object);
if (position != mCurrentPosition) {
Fragment fragment = (Fragment) object;
CustomPager pager = (CustomPager) container;
if (fragment != null && fragment.getView() != null) {
mCurrentPosition = position;
pager.measureCurrentView(fragment.getView());
}
}
}
Here is the link to GitHub project with these tweaks:
https://github.com/vabhishek/WrapContentViewPagerDemo

#abhishek's ans does what is required but the code below also adds animation during height change
public class WrappingViewPager extends ViewPager {
private Boolean mAnimStarted = false;
public WrappingViewPager(Context context) {
super(context);
}
public WrappingViewPager(Context context, AttributeSet attrs){
super(context, attrs);
}
#TargetApi(Build.VERSION_CODES.JELLY_BEAN)
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if(!mAnimStarted && null != getAdapter()) {
int height = 0;
View child = ((FragmentPagerAdapter) getAdapter()).getItem(getCurrentItem()).getView();
if (child != null) {
child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
height = child.getMeasuredHeight();
if (VersionUtils.isJellyBean() && height < getMinimumHeight()) {
height = getMinimumHeight();
}
}
// Not the best place to put this animation, but it works pretty good.
int newHeight = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
if (getLayoutParams().height != 0 && heightMeasureSpec != newHeight) {
final int targetHeight = height;
final int currentHeight = getLayoutParams().height;
final int heightChange = targetHeight - currentHeight;
Animation a = new Animation() {
#Override
protected void applyTransformation(float interpolatedTime, Transformation t) {
if (interpolatedTime >= 1) {
getLayoutParams().height = targetHeight;
} else {
int stepHeight = (int) (heightChange * interpolatedTime);
getLayoutParams().height = currentHeight + stepHeight;
}
requestLayout();
}
#Override
public boolean willChangeBounds() {
return true;
}
};
a.setAnimationListener(new Animation.AnimationListener() {
#Override
public void onAnimationStart(Animation animation) {
mAnimStarted = true;
}
#Override
public void onAnimationEnd(Animation animation) {
mAnimStarted = false;
}
#Override
public void onAnimationRepeat(Animation animation) {
}
});
a.setDuration(1000);
startAnimation(a);
mAnimStarted = true;
} else {
heightMeasureSpec = newHeight;
}
}
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}

Just in case someone else find this post like me. Worked version without bug of initially zero height:
public class DynamicHeightViewPager extends ViewPager {
private View mCurrentView;
public DynamicHeightViewPager(Context context) {
super(context);
}
public DynamicHeightViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (mCurrentView != null) {
mCurrentView.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
int height = Math.max(0, mCurrentView.getMeasuredHeight());
heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
public void measureCurrentView(View currentView) {
mCurrentView = currentView;
requestLayout();
}
}
And used it in custom FragmentPagerAdapter, like this
public abstract class AutoheightFragmentPagerAdapter extends FragmentPagerAdapter {
private int mCurrentPosition = -1;
public AutoheightFragmentPagerAdapter(FragmentManager fm) {
super(fm);
}
#Override
public void setPrimaryItem(ViewGroup container, int position, Object object) {
super.setPrimaryItem(container, position, object);
if (position != mCurrentPosition && container instanceof DynamicHeightViewPager) {
Fragment fragment = (Fragment) object;
DynamicHeightViewPager pager = (DynamicHeightViewPager) container;
if (fragment != null && fragment.getView() != null) {
mCurrentPosition = position;
pager.measureCurrentView(fragment.getView());
}
}
}
}

Adding to #vihaan's solution, if you have a PagerTitleStrip or PagetTabStrip, you can add this
// Account for pagerTitleStrip or pagerTabStrip
View tabStrip = getChildAt(0);
if (tabStrip instanceof PagerTitleStrip) {
tabStrip.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(getMeasuredWidth(), MeasureSpec.UNSPECIFIED));
height += tabStrip.getMeasuredHeight();
}
just before starting the animation (before the comment
// Not the best place to put this animation, but it works pretty good.
so that the height of the strip is taken into account.

public class WrapContentViewPager extends ViewPager {
private Boolean mAnimStarted = false;
public WrapContentViewPager(Context context) {
super(context);
}
public WrapContentViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
#TargetApi(Build.VERSION_CODES.JELLY_BEAN)
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (!mAnimStarted && null != getAdapter()) {
int height = 0;
View child = ((CommonViewPagerAdapter) getAdapter()).getItem(getCurrentItem()).getView();
if (child != null) {
child.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
height = child.getMeasuredHeight();
if (height < getMinimumHeight()) {
height = getMinimumHeight();
}
}
// Not the best place to put this animation, but it works pretty good.
int newHeight = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
if (getLayoutParams().height != 0 && heightMeasureSpec != newHeight) {
final int targetHeight = height;
final int currentHeight = getLayoutParams().height;
final int heightChange = targetHeight - currentHeight;
Animation a = new Animation() {
#Override
protected void applyTransformation(float interpolatedTime, Transformation t) {
if (interpolatedTime >= 1) {
getLayoutParams().height = targetHeight;
} else {
int stepHeight = (int) (heightChange * interpolatedTime);
getLayoutParams().height = currentHeight + stepHeight;
}
requestLayout();
}
#Override
public boolean willChangeBounds() {
return true;
}
};
a.setAnimationListener(new Animation.AnimationListener() {
#Override
public void onAnimationStart(Animation animation) {
mAnimStarted = true;
}
#Override
public void onAnimationEnd(Animation animation) {
mAnimStarted = false;
}
#Override
public void onAnimationRepeat(Animation animation) {
}
});
a.setDuration(100);
startAnimation(a);
mAnimStarted = true;
} else {
heightMeasureSpec = newHeight;
}
}
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
==============================
wrapContentViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
wrapContentViewPager.measure(wrapContentViewPager.getMeasuredWidth(), wrapContentViewPager.getMeasuredHeight());
}
#Override
public void onPageScrollStateChanged(int state) {
}
});

This few lines of code will solve the problem.
Create a custome widget for viewpager class. and in xml use it for viewpager.
public class DynamicHeightViewPager extends ViewPager {
private View mCurrentView;
public DynamicHeightViewPager(Context context) {
super(context);
}
public DynamicHeightViewPager(Context context, AttributeSet attrs) {
super(context, attrs);
}
#Override
public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (mCurrentView != null) {
mCurrentView.measure(widthMeasureSpec, MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED));
int height = Math.max(0, mCurrentView.getMeasuredHeight());
heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
public void measureCurrentView(View currentView) {
mCurrentView = currentView;
requestLayout();
}
}
Then in the view pager adapter override the below method and add the code.
#Override
public void setPrimaryItem(#NonNull ViewGroup container, int position, #NonNull Object object) {
super.setPrimaryItem(container, position, object);
if (container instanceof DynamicHeightViewPager) {
// instead of card view give your root view from your item.xml file.
CardView cardView = (CardView) object;
((DynamicHeightViewPager) container).measureCurrentView(cardView);
}
}
Make your view pager height wrap_content inside xml file so you can check the result.