Tab not taking full width on Tablet device [Using android.support.design.widget.TabLayout]

I have setup tabs as UPDATE 29/05/2015 this post. Tabs take full width on my Nexus 4 mobile but on nexus 7 tablet it in center and not cover full screen width.

Nexus 7 screenshot Nexus 4 screenshot

A "simpler" answer borrowed from Kaizie would just be adding app:tabMaxWidth="0dp" in your TabLayout xml:

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

I had the same problem and I checked the TabLayout style, and i found that its default style is Widget.Design.TabLayout which has different implementations (normal, landscape and sw600dp).

The one we need is the one for tablets (sw600dp) which has the following implementation:

<style name="Widget.Design.TabLayout" parent="Base.Widget.Design.TabLayout">
        <item name="tabGravity">center</item>
        <item name="tabMode">fixed</item>
 </style>

From this style we will use "tabGravity" (which possible values are "center" or "fill") using the "fill" value.

But we need to go deeper, and then we see that this one extends from Base.Widget.Design.TabLayout, which implementation is:

<style name="Base.Widget.Design.TabLayout" parent="android:Widget">
    <item name="tabMaxWidth">@dimen/tab_max_width</item>
    <item name="tabIndicatorColor">?attr/colorAccent</item>
    <item name="tabIndicatorHeight">2dp</item>
    <item name="tabPaddingStart">12dp</item>
    <item name="tabPaddingEnd">12dp</item>
    <item name="tabBackground">?attr/selectableItemBackground</item>
    <item name="tabTextAppearance">@style/TextAppearance.Design.Tab</item>
    <item name="tabSelectedTextColor">?android:textColorPrimary</item>
</style>

So, from this style we will need to override "tabMaxWidth". In my case I set it to 0dp, so it has no limit.

And my style looked like this:

<style name="MyTabLayout" parent="Widget.Design.TabLayout">
        <item name="tabGravity">fill</item>
        <item name="tabMaxWidth">0dp</item>
</style>

And then the tab bar will fill the whole screen from side to side.

Solution for scrollable: (TabLayout.MODE_SCROLLABLE), that is when ever you need more than 2 tabs (Dynamic tabs)

Step 1 : style.xml

<style name="tabCustomStyle" parent="Widget.Design.TabLayout">
            <item name="tabGravity">fill</item>
            <item name="tabMaxWidth">0dp</item>
            <item name="tabIndicatorColor">#FFFEEFC4</item>
            <item name="tabIndicatorHeight">2dp</item>
            <item name="tabTextAppearance">@style/MyCustomTabTextAppearance</item>
            <item name="tabSelectedTextColor">#FFFEEFC4</item>
        </style>
    
        <style name="MyCustomTabTextAppearance" parent="TextAppearance.Design.Tab">
            <item name="android:textSize">@dimen/tab_text_size</item>
            <item name="android:textAppearance">@style/TextAppearance.roboto_medium</item>
            <item name="textAllCaps">true</item>
        </style>
        <style name="TextAppearance.roboto_medium" parent="android:TextAppearance">
            <item name="android:fontFamily">sans-serif-medium</item>
        </style>

Step 2 : Your xml layout

<android.support.design.widget.TabLayout
            android:id="@+id/sliding_tabs"
            style="@style/tabCustomStyle"
            android:layout_width="match_parent"
            android:layout_height="@dimen/tab_strip_height"
            android:background="@color/your_color"
            app:tabMode="scrollable"
            app:tabTextColor="@color/your_color" />

Step 3: In your Activity/Fragment where ever you have tabs.

/**
     * To allow equal width for each tab, while (TabLayout.MODE_SCROLLABLE)
     */
    private void allotEachTabWithEqualWidth() {

        ViewGroup slidingTabStrip = (ViewGroup) mTabLayout.getChildAt(0);
        for (int i = 0; i < mTabLayout.getTabCount(); i++) {
            View tab = slidingTabStrip.getChildAt(i);
            LinearLayout.LayoutParams layoutParams = (LinearLayout.LayoutParams) tab.getLayoutParams();
            layoutParams.weight = 1;
            tab.setLayoutParams(layoutParams);
        }

    }

To force tabs to take up the full width (split into equal sizes), apply the following to the TabLayout view:

TabLayout tabLayout = (TabLayout) findViewById(R.id.your_tab_layout);
tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
tabLayout.setTabMode(TabLayout.MODE_FIXED);

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

work for me. This also have xmlns:app="http://schemas.android.com/apk/res-auto"

This is helpful you must try

 <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"
        app:tabIndicatorColor="@color/white"
        app:tabSelectedTextColor="@color/white"
        app:tabTextColor="@color/orange" />

For me the following code worked and was enough.

<android.support.design.widget.TabLayout
        android:id="@+id/tabs"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:tabGravity="fill"/>

Solution for Scrollable (Kotlin)

In xml:

     <com.google.android.material.tabs.TabLayout
            android:id="@+id/home_tab_layout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            app:tabMaxWidth="0dp"
            app:tabMode="scrollable"
            android:fillViewport="true"
            app:tabGravity="fill" />

In Kotlin:

In my case if less than 3 tabs I allocate equal space.

Note: If condition is as per your requirement

        if(list.size <= 3){
          allotEachTabWithEqualWidth(your_tab_layout)
        }

     fun allotEachTabWithEqualWidth(tabLayout: TabLayout) {
        tabLayout.tabMode=  TabLayout.MODE_SCROLLABLE
        val slidingTabStrip = tabLayout.getChildAt(0) as ViewGroup
        for (i in 0 until tabLayout.getTabCount()) {
            val tab = slidingTabStrip.getChildAt(i)
            val layoutParams = tab.layoutParams as LinearLayout.LayoutParams
            layoutParams.weight = 1f
            tab.layoutParams = layoutParams
        }

    }

Just did this and worked like a charm

<com.google.android.material.tabs.TabLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:tabGravity="fill"
    app:tabMaxWidth="0dp"/>

Check below code for solutions.

Below is layout code:

<com.yourpackage.CustomTabLayout
    android:id="@+id/tabs"
    android:layout_width="match_parent"
    android:layout_height="?attr/actionBarSize"
    android:background="@color/off_white"
    app:tabIndicatorColor="@color/primaryColor"
    app:tabIndicatorHeight="3dp"
    app:tabMode="scrollable"
    app:tabPaddingEnd="0dp"
    app:tabPaddingStart="0dp" />

Note, for dynamic tab count, don't forget to call setTabNumbers(tabcount).

import android.content.Context;
import android.support.design.widget.TabLayout;
import android.util.AttributeSet;
import android.util.
import java.lang.reflect.Field;

public class CustomTabLayout extends TabLayout
{
    private static final int WIDTH_INDEX = 0;
    private int DIVIDER_FACTOR = 3;
    private static final String SCROLLABLE_TAB_MIN_WIDTH = "mScrollableTabMinWidth";

    public CustomTabLayout(Context context) {
        super(context);
        initTabMinWidth();
    }

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

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

    public void setTabNumbers(int num)
    {
        this.DIVIDER_FACTOR = num;
        initTabMinWidth();
    }

    private void initTabMinWidth()
    {
        int[] wh = getScreenSize(getContext());
        int tabMinWidth = wh[WIDTH_INDEX] / DIVIDER_FACTOR;

        Log.v("CUSTOM TAB LAYOUT", "SCREEN WIDTH = " + wh[WIDTH_INDEX] + " && tabTotalWidth = " + (tabMinWidth*DIVIDER_FACTOR) + " && TotalTabs = " + DIVIDER_FACTOR);

        Field field;
        try {
            field = TabLayout.class.getDeclaredField(SCROLLABLE_TAB_MIN_WIDTH);
            field.setAccessible(true);
            field.set(this, tabMinWidth);
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private static final int WIDTH_INDEX = 0;
	private static final int HEIGHT_INDEX = 1;

	public static int[] getScreenSize(Context context) {
		int[] widthHeight = new int[2];
		widthHeight[WIDTH_INDEX] = 0;
		widthHeight[HEIGHT_INDEX] = 0;

		try {
			WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
			Display display = windowManager.getDefaultDisplay();

			Point size = new Point();
			display.getSize(size);
			widthHeight[WIDTH_INDEX] = size.x;
			widthHeight[HEIGHT_INDEX] = size.y;

			if (!isScreenSizeRetrieved(widthHeight))
            {
                DisplayMetrics metrics = new DisplayMetrics();
                display.getMetrics(metrics);
                widthHeight[0] = metrics.widthPixels;
                widthHeight[1] = metrics.heightPixels;
            }

			// Last defense. Use deprecated API that was introduced in lower than API 13
			if (!isScreenSizeRetrieved(widthHeight)) {
                widthHeight[0] = display.getWidth(); // deprecated
                widthHeight[1] = display.getHeight(); // deprecated
            }
		} catch (Exception e) {
			e.printStackTrace();
		}

		return widthHeight;
	}

	private static boolean isScreenSizeRetrieved(int[] widthHeight) {
		return widthHeight[WIDTH_INDEX] != 0 && widthHeight[HEIGHT_INDEX] != 0;
	}
}

Reference taken from https://medium.com/@elsenovraditya/set-tab-minimum-width-of-scrollable-tablayout-programmatically-8146d6101efe

Why all that hectic work ? Just put app:tabMode="scrollable" in your TabLayout in XML. Thats it.

In my variant of this problem, I had 3 tabs of moderate size which weren't taking up full width on tablets. I didn't need the tabs to be scrollable on tablets, since tablets are big enough to display the tabs all together without any scrolling. But I did need the tabs to be scrollable on phones, since phones are too small to display all the tabs together.

The best solution in my case was to add a res/layout-sw600dp/main_activity.xml file, where the relevant TabLayout could have app:tabGravity="fill" and app:tabMode="fixed". But in my regular res/layout/main_activity.xml, I left out app:tabGravity="fill" and app:tabMode="fixed", and had app:tabMode="scrollable" instead.

Please note that you also need to set

  app:tabPaddingStart="-1dp"
  app:tabPaddingEnd="-1dp"

to fill all space