Android - ViewPager tab not showing first time

Question

I have a tablayout with viewpager and a recyclerview inside... I've override the onMeasure method... The first time I open the fragment, the fragment inside the viewpager not show, but if i change tab it appear and if i go back to the tab that doesn't show, it begin to show... Can some one help me please!!!

I Think i saw is the viewpager get visible on screen if it fit on the screen, if i need to scroll the screen to see the viewpager it begin hided until i go to another tab and back again to see the content.

I got diferent sizes of contents inside the viewpager, that's why i need to use a custom view pager and override the onMeasure...

The source code below...

THE VIEW PAGER

public class CustomPager extends ViewPager {

    private int mCurrentPagePosition = 0;

    public CustomPager(Context context) {
        super(context);
    }

    public CustomPager(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        try {
            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();
    }
}

THE SCROLLVIEW

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));
        }
    }
}

THE LAYOUT

<LinearLayout 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"
    android:orientation="vertical"
    tools:context="br.com.ole.oleconsignado.ui.fragment.main.LastEntriesFragment">

    <View
        android:id="@+id/vw_divider"
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:layout_marginTop="@dimen/dimen_mdpi"
        android:layout_marginLeft="@dimen/dimen_mdpi"
        android:layout_marginRight="@dimen/dimen_mdpi"
        android:layout_marginEnd="@dimen/dimen_mdpi"
        android:layout_marginStart="@dimen/dimen_mdpi"
        android:background="@color/colorGrey"/>

    <android.support.design.widget.TabLayout
        android:id="@+id/tab_layout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:tabIndicatorColor="@color/colorLightBlue"
        app:tabSelectedTextColor="@color/colorLightBlue"
        android:layout_marginLeft="@dimen/dimen_mdpi"
        android:layout_marginRight="@dimen/dimen_mdpi">

        <android.support.design.widget.TabItem
            android:id="@+id/tab_national"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/title_national" />

        <android.support.design.widget.TabItem
            android:id="@+id/tab_international"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/title_international" />

    </android.support.design.widget.TabLayout>

    <br.com.ole.oleconsignado.util.CustomScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <br.com.ole.oleconsignado.util.CustomPager
            android:id="@+id/vp_pager"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="@dimen/dimen_mdpi" />

    </br.com.ole.oleconsignado.util.CustomScrollView>
</LinearLayout>

I realy don't know why it happen... Please, help me!

Here some examples similar...

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ViewPager wrap_content not working

Android - ViewPager tab not showing first time

Answer 1

Sorry I couldn't understan your use-case completely but I think I can help.

Are You Trying to get any sort Dimensional-Measurements from the activity?

If Yes Then unfortunately the activities and fragments are not completely generated until onPause()

but you can try to do this-

Create a variable of your parent layout in your activity ;

    RelativeLayout canvas;

            canvas = (RelativeLayout) findViewById(R.id.canvas);

 canvas.getViewTreeObserver().addOnGlobalLayoutListener(new 
 ViewTreeObserver.OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {

 canvas.getViewTreeObserver().removeOnGlobalLayoutListener(this);

     /* Code to get dimensional measurements */


        }
    });

Hope It Helps :)