Android Support Design TabLayout: Gravity Center a

问题:

I am trying to use the new Design TabLayout in my project. I want the layout to adapt to every screen size and orientation, but it can be seen correctly in one orientation.

I am dealing with Gravity and Mode setting my tabLayout as:

    tabLayout.setTabGravity(TabLayout.GRAVITY_CENTER);
    tabLayout.setTabMode(TabLayout.MODE_SCROLLABLE);

So I expect that if there is no room, the tabLayout is scrollable, but if there is room, it is centered.

From the guides:

public static final int GRAVITY_CENTER Gravity used to lay out the tabs in the center of the TabLayout.

public static final int GRAVITY_FILL Gravity used to fill the TabLayout as much as possible. This option only takes effect when used with MODE_FIXED.

public static final int MODE_FIXED Fixed tabs display all tabs concurrently and are best used with content that benefits from quick pivots between tabs. The maximum number of tabs is limited by the view’s width. Fixed tabs have equal width, based on the widest tab label.

public static final int MODE_SCROLLABLE Scrollable tabs display a subset of tabs at any given moment, and can contain longer tab labels and a larger number of tabs. They are best used for browsing contexts in touch interfaces when users don’t need to directly compare the tab labels.

So GRAVITY_FILL is compatible only with MODE_FIXED but, at is doesn't specify anything for GRAVITY_CENTER, I expect it to be compatible with MODE_SCROLLABLE, but this is what I get using GRAVITY_CENTER and MODE_SCROLLABLE

So it is using SCROLLABLE in both orientations, but it is not using GRAVITY_CENTER.

This is what I would expect for landscape; but to have this, I need to set MODE_FIXED, so what I get in portrait is:

Why is GRAVITY_CENTER not working for SCROLLABLE if the tabLayout fits the screen? Is there any way to set gravity and mode dynamically (and to see what I am expecting)?

Thank you very much!

EDITED: This is the Layout of my TabLayout:

<android.support.design.widget.TabLayout
    android:id="@+id/sliding_tabs"
    android:layout_width="match_parent"
    android:background="@color/orange_pager"
    android:layout_height="wrap_content" />

回答1:

Tab gravity only effects MODE_FIXED.

One possible solution is to set your layout_width to wrap_content and layout_gravity to center_horizontal:

<android.support.design.widget.TabLayout
    android:id="@+id/sliding_tabs"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    app:tabMode="scrollable" />

If the tabs are smaller than the screen width, the TabLayout itself will also be smaller and it will be centered because of the gravity. If the tabs are bigger than the screen width, the TabLayout will match the screen width and scrolling will activate.

回答2:

this is how i did it

TabLayout.xml

<android.support.design.widget.TabLayout
            android:id="@+id/tab_layout"
            android:layout_height="wrap_content"
            android:layout_width="wrap_content"
            android:background="@android:color/transparent"
            app:tabGravity="fill"
            app:tabMode="scrollable"
            app:tabTextAppearance="@style/TextAppearance.Design.Tab"
            app:tabSelectedTextColor="@color/myPrimaryColor"
            app:tabIndicatorColor="@color/myPrimaryColor"
            android:overScrollMode="never"
            />

Oncreate

@Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mToolbar = (Toolbar) findViewById(R.id.toolbar_actionbar);
        mTabLayout = (TabLayout)findViewById(R.id.tab_layout);
        mTabLayout.setOnTabSelectedListener(this);
        setSupportActionBar(mToolbar);

        mTabLayout.addTab(mTabLayout.newTab().setText("Dashboard"));
        mTabLayout.addTab(mTabLayout.newTab().setText("Signature"));
        mTabLayout.addTab(mTabLayout.newTab().setText("Booking/Sampling"));
        mTabLayout.addTab(mTabLayout.newTab().setText("Calendar"));
        mTabLayout.addTab(mTabLayout.newTab().setText("Customer Detail"));

        mTabLayout.post(mTabLayout_config);
    }

    Runnable mTabLayout_config = new Runnable()
    {
        @Override
        public void run()
        {

           if(mTabLayout.getWidth() < MainActivity.this.getResources().getDisplayMetrics().widthPixels)
            {
                mTabLayout.setTabMode(TabLayout.MODE_FIXED);
                ViewGroup.LayoutParams mParams = mTabLayout.getLayoutParams();
                mParams.width = ViewGroup.LayoutParams.MATCH_PARENT;
                mTabLayout.setLayoutParams(mParams);

            }
            else
            {
                mTabLayout.setTabMode(TabLayout.MODE_SCROLLABLE);
            }
        }
    };

I made small changes of @Mario Velasco's solution on the runnable part

回答3:

Look at android-tablayouthelper

Automatically switch TabLayout.MODE_FIXED and TabLayout.MODE_SCROLLABLE depends on total tab width.

回答4:

keeps things simple just add app:tabMode="scrollable" and android:layout_gravity= "bottom"

just like this

<android.support.design.widget.TabLayout
android:id="@+id/tabs"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:layout_gravity="bottom"
app:tabMode="scrollable"
app:tabIndicatorColor="@color/colorAccent" />

回答5:

As I didn't find why does this behaviour happen I have used the following code:

float myTabLayoutSize = 360;
if (DeviceInfo.getWidthDP(this) >= myTabLayoutSize ){
    tabLayout.setTabMode(TabLayout.MODE_FIXED);
} else {
    tabLayout.setTabMode(TabLayout.MODE_SCROLLABLE);
}

Basically, I have to calculate manually the width of my tabLayout and then I set the Tab Mode depending on if the tabLayout fits in the device or not.

The reason why I get the size of the layout manually is because not all the tabs have the same width in Scrollable mode, and this could provoke that some names use 2 lines as it happened to me in the example.

回答6:

This is the solution I used to automatically change between SCROLLABLE and FIXED+FILL. It is the complete code for the @Fighter42 solution:

(The code below shows where to put the modification if you've used Google's tabbed activity template)

@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    // Create the adapter that will return a fragment for each of the three
    // primary sections of the activity.
    mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.container);
    mViewPager.setAdapter(mSectionsPagerAdapter);

    // Set up the tabs
    final TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
    tabLayout.setupWithViewPager(mViewPager);

    // Mario Velasco's code
    tabLayout.post(new Runnable()
    {
        @Override
        public void run()
        {
            int tabLayoutWidth = tabLayout.getWidth();

            DisplayMetrics metrics = new DisplayMetrics();
            ActivityMain.this.getWindowManager().getDefaultDisplay().getMetrics(metrics);
            int deviceWidth = metrics.widthPixels;

            if (tabLayoutWidth < deviceWidth)
            {
                tabLayout.setTabMode(TabLayout.MODE_FIXED);
                tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);
            } else
            {
                tabLayout.setTabMode(TabLayout.MODE_SCROLLABLE);
            }
        }
    });
}

Layout:

    <android.support.design.widget.TabLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal" />

If you don't need to fill width, better to use @karaokyo solution.

回答7:

I created an AdaptiveTabLayout class to achieve this. This was the only way I found to actually solve the problem, answer the question and avoid/workaround problems that other answers here don't.

Notes:

• Handles phone/tablet layouts.
• Handles cases where there's enough room for MODE_SCROLLABLE but not enough room for MODE_FIXED. If you don't handle this case it's gonna happen on some devices you'll see different text sizes or oven two lines of text in some tabs, which looks bad.
• It gets real measures and doesn't make any assumptions (like screen is 360dp wide or whatever...). This works with real screen sizes and real tab sizes. This means works well with translations because doesn't assume any tab size, the tabs get measure.
• Deals with the different passes on the onLayout phase in order to avoid extra work.
• Layout width needs to be wrap_content on the xml. Don't set any mode or gravity on the xml.

AdaptiveTabLayout.java

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.design.widget.TabLayout;
import android.util.AttributeSet;
import android.widget.LinearLayout;

public class AdaptiveTabLayout extends TabLayout
{
    private boolean mGravityAndModeSeUpNeeded = true;

    public AdaptiveTabLayout(@NonNull final Context context)
    {
        this(context, null);
    }

    public AdaptiveTabLayout(@NonNull final Context context, @Nullable final AttributeSet attrs)
    {
        this(context, attrs, 0);
    }

    public AdaptiveTabLayout
    (
            @NonNull final Context context,
            @Nullable final AttributeSet attrs,
            final int defStyleAttr
    )
    {
        super(context, attrs, defStyleAttr);
        setTabMode(MODE_SCROLLABLE);
    }

    @Override
    protected void onLayout(final boolean changed, final int l, final int t, final int r, final int b)
    {
        super.onLayout(changed, l, t, r, b);

        if (mGravityAndModeSeUpNeeded)
        {
            setModeAndGravity();
        }
    }

    private void setModeAndGravity()
    {
        final int tabCount = getTabCount();
        final int screenWidth = UtilsDevice.getScreenWidth();
        final int minWidthNeedForMixedMode = getMinSpaceNeededForFixedMode(tabCount);

        if (minWidthNeedForMixedMode == 0)
        {
            return;
        }
        else if (minWidthNeedForMixedMode < screenWidth)
        {
            setTabMode(MODE_FIXED);
            setTabGravity(UtilsDevice.isBigTablet() ? GRAVITY_CENTER : GRAVITY_FILL) ;
        }
        else
        {
            setTabMode(TabLayout.MODE_SCROLLABLE);
        }

        setLayoutParams(new LinearLayout.LayoutParams
                (LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));

        mGravityAndModeSeUpNeeded = false;
    }

    private int getMinSpaceNeededForFixedMode(final int tabCount)
    {
        final LinearLayout linearLayout = (LinearLayout) getChildAt(0);
        int widestTab = 0;
        int currentWidth;

        for (int i = 0; i < tabCount; i++)
        {
            currentWidth = linearLayout.getChildAt(i).getWidth();

            if (currentWidth == 0) return 0;

            if (currentWidth > widestTab)
            {
                widestTab = currentWidth;
            }
        }

        return widestTab * tabCount;
    }

}

And this is the DeviceUtils class:

import android.content.res.Resources;

public class UtilsDevice extends Utils
{
    private static final int sWIDTH_FOR_BIG_TABLET_IN_DP = 720;

    private UtilsDevice() {}

    public static int pixelToDp(final int pixels)
    {
        return (int) (pixels / Resources.getSystem().getDisplayMetrics().density);
    }

    public static int getScreenWidth()
    {
        return Resources
                .getSystem()
                .getDisplayMetrics()
                .widthPixels;
    }

    public static boolean isBigTablet()
    {
        return pixelToDp(getScreenWidth()) >= sWIDTH_FOR_BIG_TABLET_IN_DP;
    }

}

Use example:

<?xml version="1.0" encoding="utf-8"?>

<FrameLayout
    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">

    <com.com.stackoverflow.example.AdaptiveTabLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="?colorPrimary"
        app:tabIndicatorColor="@color/white"
        app:tabSelectedTextColor="@color/text_white_primary"
        app:tabTextColor="@color/text_white_secondary"
        tools:layout_width="match_parent"/>

</FrameLayout>

Gist

Problems/Ask for help:

• You'll see this:

Logcat:

W/View: requestLayout() improperly called by android.support.design.widget.TabLayout$SlidingTabStrip{3e1ebcd6 V.ED.... ......ID 0,0-466,96} during layout: running second layout pass
W/View: requestLayout() improperly called by android.support.design.widget.TabLayout$TabView{3423cb57 VFE...C. ..S...ID 0,0-144,96} during layout: running second layout pass
W/View: requestLayout() improperly called by android.support.design.widget.TabLayout$TabView{377c4644 VFE...C. ......ID 144,0-322,96} during layout: running second layout pass
W/View: requestLayout() improperly called by android.support.design.widget.TabLayout$TabView{19ead32d VFE...C. ......ID 322,0-466,96} during layout: running second layout pass

I'm not sure how to solve it. Any suggestions?

• To make the TabLayout child measures, I'm making some castings and assumptions (Like the child is a LinearLayout containing other views....) This might cause problems with in further Design Support Library updates. A better approach/suggestions?

回答8:

This is the only code that worked for me:

public static void adjustTabLayoutBounds(final TabLayout tabLayout,
                                         final DisplayMetrics displayMetrics){

    final ViewTreeObserver vto = tabLayout.getViewTreeObserver();
    vto.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {

        @Override
        public void onGlobalLayout() {

            tabLayout.getViewTreeObserver().removeOnGlobalLayoutListener(this);

            int totalTabPaddingPlusWidth = 0;
            for(int i=0; i < tabLayout.getTabCount(); i++){

                final LinearLayout tabView = ((LinearLayout)((LinearLayout) tabLayout.getChildAt(0)).getChildAt(i));
                totalTabPaddingPlusWidth += (tabView.getMeasuredWidth() + tabView.getPaddingLeft() + tabView.getPaddingRight());
            }

            if (totalTabPaddingPlusWidth <= displayMetrics.widthPixels){

                tabLayout.setTabMode(TabLayout.MODE_FIXED);
                tabLayout.setTabGravity(TabLayout.GRAVITY_FILL);

            }else{
                tabLayout.setTabMode(TabLayout.MODE_SCROLLABLE);
            }

            tabLayout.setLayoutParams(new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));
        }
    });
}

The DisplayMetrics can be retrieved using this:

public DisplayMetrics getDisplayMetrics() {

    final WindowManager wm = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
    final Display display = wm.getDefaultDisplay();
    final DisplayMetrics displayMetrics = new DisplayMetrics();

    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1) {
        display.getMetrics(displayMetrics);

    }else{
        display.getRealMetrics(displayMetrics);
    }

    return displayMetrics;
}

And your TabLayout XML should look like this (don't forget to set tabMaxWidth to 0):

<android.support.design.widget.TabLayout
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/tab_layout"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    app:tabMaxWidth="0dp"/>

回答9:

All you need is to add the following to your TabLayout

custom:tabGravity="fill"

So then you'll have:

xmlns:custom="http://schemas.android.com/apk/res-auto"
<android.support.design.widget.TabLayout
        android:id="@+id/tabs"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        custom:tabGravity="fill"
        />

回答10:

I solved this using following

if(tabLayout_chemistCategory.getTabCount()<4)
    {
        tabLayout_chemistCategory.setTabGravity(TabLayout.GRAVITY_FILL);
    }else
    {
        tabLayout_chemistCategory.setTabMode(TabLayout.MODE_SCROLLABLE);

    }