import android.content.Context;
import android.os.Build;
import android.support.annotation.NonNull;
import android.support.design.widget.TabLayout;
import android.util.AttributeSet;

/**
 * Created by dale on 2/28/17.
 * Tab Layout that auto converts from MODE_FIXED to MODE_SCROLLABLE when the tabs don't fit anymore.
 */

public class FillScrollableTabLayout extends TabLayout {

    private int scrollableTabMinWidth;

    public FillScrollableTabLayout(Context context) {
        super(context);
        initialize();
    }

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

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

    private void initialize() {
        // waiting for google to make this an attr
        scrollableTabMinWidth = getResources()
                .getDimensionPixelSize(android.support.design.R.dimen.design_tab_scrollable_min_width);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        adjustSize();
    }

    @Override
    public void addTab(@NonNull Tab tab) {
        super.addTab(tab);
    }

    private void adjustSize() {
        int totalTabSize = 0;
        for(int i=0; i < getTabCount(); i++) {
            if(getTabAt(i).getCustomView() != null) {
                totalTabSize += getTabAt(i).getCustomView().getMeasuredWidth() > scrollableTabMinWidth ?
                        getTabAt(i).getCustomView().getMeasuredWidth() : scrollableTabMinWidth;
            }
        }

        if(totalTabSize >= getMeasuredWidth()) {
            setTabMode(TabLayout.MODE_SCROLLABLE);
        }
        else {
            setTabMode(TabLayout.MODE_FIXED);
            setTabGravity(TabLayout.GRAVITY_FILL);
        }
    }
}