TabLayout not filling width when tabMode set to 'scrollable'

Question

I have added TabLayout (from support library v22.2.1) to my Fragment as:

<android.support.design.widget.TabLayout
        android:id="@+id/tabs"
        style="@style/MyColorAccentTabLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:tabMode="scrollable"/>

The issue is that when the Fragment's orientation is landscape (before or after the initial creation of the fragment), the TabLayout doesn't match the width of the Fragment (yes the parent has its width set to match_parent as well).

When screen width is small (i.e not all tabs can be shown at same time):

When screen width is big enough to show all tabs (see the blank space at the right):

If I change tabMode to fixed, width is filled but tabs are too small. Is there any proper solution out there?

Answer 1

androidx version:

<androidx.viewpager.widget.ViewPager
    android:id="@+id/view_pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior" >
    <com.google.android.material.tabs.TabLayout
        android:id="@+id/tabs"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:tabMaxWidth="0dp"
        app:tabGravity="fill"
        app:tabMode="fixed"
        />
</androidx.viewpager.widget.ViewPager>

***** BELOW IS OLD ANSWER *****

Try this one, it's a workaround which sets tabMaxWidth="0dp", tabGravity="fill" and tabMode="fixed".

 <android.support.v4.view.ViewPager
     android:id="@+id/container"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     app:layout_behavior="@string/appbar_scrolling_view_behavior">
     <android.support.design.widget.TabLayout
         android:id="@+id/tabs"
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         app:tabMaxWidth="0dp"
         app:tabGravity="fill"
         app:tabMode="fixed"/>
</android.support.v4.view.ViewPager>

Screenshot on a 10 inch tablet:

Answer 2

Instead of creating custom TabLayout and hacking around or creating more layouts which acts as wrapper around TabLayout only for background. Try this,

<android.support.design.widget.TabLayout
    android:id="@+id/tabs"
    style="@style/MyColorAccentTabLayout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    <!-- Instead of setting app:tabBackground -->
    android:background="@color/colorAccent"
    app:tabGravity="fill"
    app:tabMode="scrollable"/>

This will set background to behind tabLayout instead of setting background behind every tab.

Answer 3

I guess this is the simpliest way to achieve what you want.

public class CustomTabLayout extends TabLayout {
    public CustomTabLayout(Context context) {
        super(context);
    }

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

    public CustomTabLayout(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        try {
            if (getTabCount() == 0)
                return;
            Field field = TabLayout.class.getDeclaredField("mTabMinWidth");
            field.setAccessible(true);
            field.set(this, (int) (getMeasuredWidth() / (float) getTabCount()));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Answer 4

Here is my 2021 Kotlin solution. It achieves the following which I couldn't do from other answers:

• If not many tabs they expand to fill the whole width.
• If lots of tabs they are scrollable so they aren't squished.
• Works correctly even if tabLayout is not the full width of the screen.

To achieve this I created a subclass of TabLayout that overrides onMeasure

class ScalableTabLayout : TabLayout {
    constructor(context: Context) : super(context)
    constructor(context: Context, attrs: AttributeSet?) : super(context, attrs)
    constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : super(
        context,
        attrs,
        defStyleAttr
    )

    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
        val tabLayout = getChildAt(0) as ViewGroup
        val childCount = tabLayout.childCount
        if (childCount > 0) {
            val widthPixels = MeasureSpec.getSize(widthMeasureSpec)
            val tabMinWidth = widthPixels / childCount
            var remainderPixels = widthPixels % childCount
            tabLayout.forEachChild {
                if (remainderPixels > 0) {
                    it.minimumWidth = tabMinWidth + 1
                    remainderPixels--
                } else {
                    it.minimumWidth = tabMinWidth
                }
            }
        }
        super.onMeasure(widthMeasureSpec, heightMeasureSpec)
    }
}

And then used it in my layout file:

<com.package.name.ScalableTabLayout
    android:id="@+id/tabs"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:tabMaxWidth="0dp"
    app:tabMode="scrollable" />

both tabMaxWidth="0dp" and tabMode="scrollable" are required

Answer 5

please use this it will solve this problem definitely

<android.support.design.widget.TabLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:tabMaxWidth="0dp"
        app:tabGravity="fill"
        app:tabMode="fixed" />

Answer 6

I have tried almost all answeres, atlast found this one works like a charm.

public void dynamicSetTabLayoutMode(TabLayout tabLayout) {
            int tabWidth = calculateTabWidth(tabLayout);
            int screenWidth =  getApplicationContext().getResources().getDisplayMetrics().widthPixels;
            if (tabWidth <= screenWidth) {
                tabLayout.setTabMode(TabLayout.MODE_FIXED);
            } else {
                tabLayout.setTabMode(TabLayout.MODE_SCROLLABLE);
            }
        }
    
      private int calculateTabWidth(TabLayout tabLayout) {
            int tabWidth = 0;
            for (int i = 0; i < tabLayout.getChildCount(); i++) {
                final View view = tabLayout.getChildAt(i);
                view.measure(0, 0); 
                tabWidth += view.getMeasuredWidth();
            }
            return tabWidth;
        }