title: Android Studio: Error: Expected resource of type styleable [ResourceType]
body: <p>in android studio, when i want generate signed apk, Leads to the following error:</p>
  
  <p><code>Error:Error: Expected resource of type styleable [ResourceType]</code></p>
  
  <p>this Class is: <a href="https://github.com/astuetz/PagerSlidingTabStrip" rel="nofollow">https://github.com/astuetz/PagerSlidingTabStrip</a></p>
  
  <p>How can I fix the error?</p>
  
  <p><code>PagerSlidingTabStrip</code> class:</p>
  
  <pre><code>import android.annotation.SuppressLint;
      import android.content.Context;
      import android.content.res.TypedArray;
      import android.graphics.Canvas;
      import android.graphics.Paint;
      import android.graphics.Paint.Style;
      import android.graphics.Typeface;
      import android.os.Build;
      import android.os.Parcel;
      import android.os.Parcelable;
      import android.support.v4.view.ViewPager;
      import android.support.v4.view.ViewPager.OnPageChangeListener;
      import android.util.AttributeSet;
      import android.util.DisplayMetrics;
      import android.util.TypedValue;
      import android.view.Gravity;
      import android.view.View;
      import android.view.ViewTreeObserver.OnGlobalLayoutListener;
      import android.widget.HorizontalScrollView;
      import android.widget.ImageButton;
      import android.widget.LinearLayout;
      import android.widget.TextView;
  
      import java.util.Locale;
  
      public class PagerSlidingTabStrip extends HorizontalScrollView {
  
          public interface IconTabProvider {
              public int getPageIconResId(int position);
          }
  
          // @formatter:off
          private static final int[] ATTRS = new int[] {
              android.R.attr.textSize,
              android.R.attr.textColor
          };
          // @formatter:on
  
          private LinearLayout.LayoutParams defaultTabLayoutParams;
          private LinearLayout.LayoutParams expandedTabLayoutParams;
  
          private final PageListener pageListener = new PageListener();
          public OnPageChangeListener delegatePageListener;
  
          private LinearLayout tabsContainer;
          private ViewPager pager;
  
          private int tabCount;
  
          private int currentPosition = 0;
          private float currentPositionOffset = 0f;
  
          private Paint rectPaint;
          private Paint dividerPaint;
  
          private int indicatorColor = 0xFF666666;
          private int underlineColor = 0x1A000000;
          private int dividerColor = 0x1A000000;
  
          private boolean shouldExpand = false;
          private boolean textAllCaps = true;
  
          private int scrollOffset = 52;
          private int indicatorHeight = 8;
          private int underlineHeight = 2;
          private int dividerPadding = 12;
          private int tabPadding = 24;
          private int dividerWidth = 1;
  
          private int tabTextSize = 12;
          private int tabTextColor = 0xFF666666;
          private Typeface tabTypeface = null;
          private int tabTypefaceStyle = Typeface.BOLD;
  
          private int lastScrollX = 0;
  
          private int tabBackgroundResId = R.drawable.background_tab;
  
          private Locale locale;
  
          public PagerSlidingTabStrip(Context context) {
              this(context, null);
          }
  
          public PagerSlidingTabStrip(Context context, AttributeSet attrs) {
              this(context, attrs, 0);
          }
  
          public PagerSlidingTabStrip(Context context, AttributeSet attrs, int defStyle) {
              super(context, attrs, defStyle);
  
              setFillViewport(true);
              setWillNotDraw(false);
  
              tabsContainer = new LinearLayout(context);
              tabsContainer.setOrientation(LinearLayout.HORIZONTAL);
              tabsContainer.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
              addView(tabsContainer);
  
              DisplayMetrics dm = getResources().getDisplayMetrics();
  
              scrollOffset = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, scrollOffset, dm);
              indicatorHeight = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, indicatorHeight, dm);
              underlineHeight = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, underlineHeight, dm);
              dividerPadding = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dividerPadding, dm);
              tabPadding = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, tabPadding, dm);
              dividerWidth = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dividerWidth, dm);
              tabTextSize = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, tabTextSize, dm);
  
              // get system attrs (android:textSize and android:textColor)
  
              TypedArray a = context.obtainStyledAttributes(attrs, ATTRS);
  
              tabTextSize = a.getDimensionPixelSize(0, tabTextSize);
              tabTextColor = a.getColor(1, tabTextColor);
  
              a.recycle();
  
              // get custom attrs
  
              a = context.obtainStyledAttributes(attrs, R.styleable.PagerSlidingTabStrip);
  
              indicatorColor = a.getColor(R.styleable.PagerSlidingTabStrip_pstsIndicatorColor, indicatorColor);
              underlineColor = a.getColor(R.styleable.PagerSlidingTabStrip_pstsUnderlineColor, underlineColor);
              dividerColor = a.getColor(R.styleable.PagerSlidingTabStrip_pstsDividerColor, dividerColor);
              indicatorHeight = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_pstsIndicatorHeight, indicatorHeight);
              underlineHeight = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_pstsUnderlineHeight, underlineHeight);
              dividerPadding = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_pstsDividerPadding, dividerPadding);
              tabPadding = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_pstsTabPaddingLeftRight, tabPadding);
              tabBackgroundResId = a.getResourceId(R.styleable.PagerSlidingTabStrip_pstsTabBackground, tabBackgroundResId);
              shouldExpand = a.getBoolean(R.styleable.PagerSlidingTabStrip_pstsShouldExpand, shouldExpand);
              scrollOffset = a.getDimensionPixelSize(R.styleable.PagerSlidingTabStrip_pstsScrollOffset, scrollOffset);
              textAllCaps = a.getBoolean(R.styleable.PagerSlidingTabStrip_pstsTextAllCaps, textAllCaps);
  
              a.recycle();
  
              rectPaint = new Paint();
              rectPaint.setAntiAlias(true);
              rectPaint.setStyle(Style.FILL);
  
              dividerPaint = new Paint();
              dividerPaint.setAntiAlias(true);
              dividerPaint.setStrokeWidth(dividerWidth);
  
              defaultTabLayoutParams = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);
              expandedTabLayoutParams = new LinearLayout.LayoutParams(0, LayoutParams.MATCH_PARENT, 1.0f);
  
              if (locale == null) {
                  locale = getResources().getConfiguration().locale;
              }
          }
  
          public void setViewPager(ViewPager pager) {
              this.pager = pager;
  
              if (pager.getAdapter() == null) {
                  throw new IllegalStateException("ViewPager does not have adapter instance.");
              }
  
              pager.setOnPageChangeListener(pageListener);
  
              notifyDataSetChanged();
          }
  
          public void setOnPageChangeListener(OnPageChangeListener listener) {
              this.delegatePageListener = listener;
          }
  
          public void notifyDataSetChanged() {
  
              tabsContainer.removeAllViews();
  
              tabCount = pager.getAdapter().getCount();
  
              for (int i = 0; i &lt; tabCount; i++) {
  
                  if (pager.getAdapter() instanceof IconTabProvider) {
                      addIconTab(i, ((IconTabProvider) pager.getAdapter()).getPageIconResId(i));
                  } else {
                      addTextTab(i, pager.getAdapter().getPageTitle(i).toString());
                  }
  
              }
  
              updateTabStyles();
  
              getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
  
                  @SuppressWarnings("deprecation")
                  @SuppressLint("NewApi")
                  @Override
                  public void onGlobalLayout() {
  
                      if (Build.VERSION.SDK_INT &lt; Build.VERSION_CODES.JELLY_BEAN) {
                          getViewTreeObserver().removeGlobalOnLayoutListener(this);
                      } else {
                          getViewTreeObserver().removeOnGlobalLayoutListener(this);
                      }
  
                      currentPosition = pager.getCurrentItem();
                      scrollToChild(currentPosition, 0);
                  }
              });
  
          }
  
          private void addTextTab(final int position, String title) {
  
              TextView tab = new TextView(getContext());
              tab.setText(title);
              tab.setGravity(Gravity.CENTER);
              tab.setSingleLine();
  
              addTab(position, tab);
          }
  
          private void addIconTab(final int position, int resId) {
  
              ImageButton tab = new ImageButton(getContext());
              tab.setImageResource(resId);
  
              addTab(position, tab);
  
          }
  
          private void addTab(final int position, View tab) {
              tab.setFocusable(true);
              tab.setOnClickListener(new OnClickListener() {
                  @Override
                  public void onClick(View v) {
                      pager.setCurrentItem(position);
                  }
              });
  
              tab.setPadding(tabPadding, 0, tabPadding, 0);
              tabsContainer.addView(tab, position, shouldExpand ? expandedTabLayoutParams : defaultTabLayoutParams);
          }
  
          private void updateTabStyles() {
  
              for (int i = 0; i &lt; tabCount; i++) {
  
                  View v = tabsContainer.getChildAt(i);
  
                  v.setBackgroundResource(tabBackgroundResId);
  
                  if (v instanceof TextView) {
  
                      TextView tab = (TextView) v;
                      tab.setTextSize(TypedValue.COMPLEX_UNIT_PX, tabTextSize);
                      tab.setTypeface(tabTypeface, tabTypefaceStyle);
                      tab.setTextColor(tabTextColor);
  
                      // setAllCaps() is only available from API 14, so the upper case is made manually if we are on a
                      // pre-ICS-build
                      if (textAllCaps) {
                          if (Build.VERSION.SDK_INT &gt;= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
                              tab.setAllCaps(true);
                          } else {
                              tab.setText(tab.getText().toString().toUpperCase(locale));
                          }
                      }
                  }
              }
  
          }
  
          private void scrollToChild(int position, int offset) {
  
              if (tabCount == 0) {
                  return;
              }
  
              int newScrollX = tabsContainer.getChildAt(position).getLeft() + offset;
  
              if (position &gt; 0 || offset &gt; 0) {
                  newScrollX -= scrollOffset;
              }
  
              if (newScrollX != lastScrollX) {
                  lastScrollX = newScrollX;
                  scrollTo(newScrollX, 0);
              }
  
          }
  
          @Override
          protected void onDraw(Canvas canvas) {
              super.onDraw(canvas);
  
              if (isInEditMode() || tabCount == 0) {
                  return;
              }
  
              final int height = getHeight();
  
              // draw indicator line
  
              rectPaint.setColor(indicatorColor);
  
              // default: line below current tab
              View currentTab = tabsContainer.getChildAt(currentPosition);
              float lineLeft = currentTab.getLeft();
              float lineRight = currentTab.getRight();
  
              // if there is an offset, start interpolating left and right coordinates between current and next tab
              if (currentPositionOffset &gt; 0f &amp;&amp; currentPosition &lt; tabCount - 1) {
  
                  View nextTab = tabsContainer.getChildAt(currentPosition + 1);
                  final float nextTabLeft = nextTab.getLeft();
                  final float nextTabRight = nextTab.getRight();
  
                  lineLeft = (currentPositionOffset * nextTabLeft + (1f - currentPositionOffset) * lineLeft);
                  lineRight = (currentPositionOffset * nextTabRight + (1f - currentPositionOffset) * lineRight);
              }
  
              canvas.drawRect(lineLeft, height - indicatorHeight, lineRight, height, rectPaint);
  
              // draw underline
  
              rectPaint.setColor(underlineColor);
              canvas.drawRect(0, height - underlineHeight, tabsContainer.getWidth(), height, rectPaint);
  
              // draw divider
  
              dividerPaint.setColor(dividerColor);
              for (int i = 0; i &lt; tabCount - 1; i++) {
                  View tab = tabsContainer.getChildAt(i);
                  canvas.drawLine(tab.getRight(), dividerPadding, tab.getRight(), height - dividerPadding, dividerPaint);
              }
          }
  
          private class PageListener implements OnPageChangeListener {
  
              @Override
              public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
  
                  currentPosition = position;
                  currentPositionOffset = positionOffset;
  
                  scrollToChild(position, (int) (positionOffset * tabsContainer.getChildAt(position).getWidth()));
  
                  invalidate();
  
                  if (delegatePageListener != null) {
                      delegatePageListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
                  }
              }
  
              @Override
              public void onPageScrollStateChanged(int state) {
                  if (state == ViewPager.SCROLL_STATE_IDLE) {
                      scrollToChild(pager.getCurrentItem(), 0);
                  }
  
                  if (delegatePageListener != null) {
                      delegatePageListener.onPageScrollStateChanged(state);
                  }
              }
  
              @Override
              public void onPageSelected(int position) {
                  if (delegatePageListener != null) {
                      delegatePageListener.onPageSelected(position);
                  }
              }
  
          }
  
          public void setIndicatorColor(int indicatorColor) {
              this.indicatorColor = indicatorColor;
              invalidate();
          }
  
          public void setIndicatorColorResource(int resId) {
              this.indicatorColor = getResources().getColor(resId);
              invalidate();
          }
  
          public int getIndicatorColor() {
              return this.indicatorColor;
          }
  
          public void setIndicatorHeight(int indicatorLineHeightPx) {
              this.indicatorHeight = indicatorLineHeightPx;
              invalidate();
          }
  
          public int getIndicatorHeight() {
              return indicatorHeight;
          }
  
          public void setUnderlineColor(int underlineColor) {
              this.underlineColor = underlineColor;
              invalidate();
          }
  
          public void setUnderlineColorResource(int resId) {
              this.underlineColor = getResources().getColor(resId);
              invalidate();
          }
  
          public int getUnderlineColor() {
              return underlineColor;
          }
  
          public void setDividerColor(int dividerColor) {
              this.dividerColor = dividerColor;
              invalidate();
          }
  
          public void setDividerColorResource(int resId) {
              this.dividerColor = getResources().getColor(resId);
              invalidate();
          }
  
          public int getDividerColor() {
              return dividerColor;
          }
  
          public void setUnderlineHeight(int underlineHeightPx) {
              this.underlineHeight = underlineHeightPx;
              invalidate();
          }
  
          public int getUnderlineHeight() {
              return underlineHeight;
          }
  
          public void setDividerPadding(int dividerPaddingPx) {
              this.dividerPadding = dividerPaddingPx;
              invalidate();
          }
  
          public int getDividerPadding() {
              return dividerPadding;
          }
  
          public void setScrollOffset(int scrollOffsetPx) {
              this.scrollOffset = scrollOffsetPx;
              invalidate();
          }
  
          public int getScrollOffset() {
              return scrollOffset;
          }
  
          public void setShouldExpand(boolean shouldExpand) {
              this.shouldExpand = shouldExpand;
              requestLayout();
          }
  
          public boolean getShouldExpand() {
              return shouldExpand;
          }
  
          public boolean isTextAllCaps() {
              return textAllCaps;
          }
  
          public void setAllCaps(boolean textAllCaps) {
              this.textAllCaps = textAllCaps;
          }
  
          public void setTextSize(int textSizePx) {
              this.tabTextSize = textSizePx;
              updateTabStyles();
          }
  
          public int getTextSize() {
              return tabTextSize;
          }
  
          public void setTextColor(int textColor) {
              this.tabTextColor = textColor;
              updateTabStyles();
          }
  
          public void setTextColorResource(int resId) {
              this.tabTextColor = getResources().getColor(resId);
              updateTabStyles();
          }
  
          public int getTextColor() {
              return tabTextColor;
          }
  
          public void setTypeface(Typeface typeface, int style) {
              this.tabTypeface = typeface;
              this.tabTypefaceStyle = style;
              updateTabStyles();
          }
  
          public void setTabBackground(int resId) {
              this.tabBackgroundResId = resId;
          }
  
          public int getTabBackground() {
              return tabBackgroundResId;
          }
  
          public void setTabPaddingLeftRight(int paddingPx) {
              this.tabPadding = paddingPx;
              updateTabStyles();
          }
  
          public int getTabPaddingLeftRight() {
              return tabPadding;
          }
  
          @Override
          public void onRestoreInstanceState(Parcelable state) {
              SavedState savedState = (SavedState) state;
              super.onRestoreInstanceState(savedState.getSuperState());
              currentPosition = savedState.currentPosition;
              requestLayout();
          }
  
          @Override
          public Parcelable onSaveInstanceState() {
              Parcelable superState = super.onSaveInstanceState();
              SavedState savedState = new SavedState(superState);
              savedState.currentPosition = currentPosition;
              return savedState;
          }
  
          static class SavedState extends BaseSavedState {
              int currentPosition;
  
              public SavedState(Parcelable superState) {
                  super(superState);
              }
  
              private SavedState(Parcel in) {
                  super(in);
                  currentPosition = in.readInt();
              }
  
              @Override
              public void writeToParcel(Parcel dest, int flags) {
                  super.writeToParcel(dest, flags);
                  dest.writeInt(currentPosition);
              }
  
              public static final Parcelable.Creator&lt;SavedState&gt; CREATOR = new Parcelable.Creator&lt;SavedState&gt;() {
                  @Override
                  public SavedState createFromParcel(Parcel in) {
                      return new SavedState(in);
                  }
  
                  @Override
                  public SavedState[] newArray(int size) {
                      return new SavedState[size];
                  }
              };
          }
  
      }
  </code></pre>
  
  <p>values/attrs.xml</p>
  
  <pre><code>&lt;declare-styleable name="PagerSlidingTabStrip"&gt;
          &lt;attr name="pstsIndicatorColor" format="color" /&gt;
          &lt;attr name="pstsUnderlineColor" format="color" /&gt;
          &lt;attr name="pstsDividerColor" format="color" /&gt;
          &lt;attr name="pstsIndicatorHeight" format="dimension" /&gt;
          &lt;attr name="pstsUnderlineHeight" format="dimension" /&gt;
          &lt;attr name="pstsDividerPadding" format="dimension" /&gt;
          &lt;attr name="pstsTabPaddingLeftRight" format="dimension" /&gt;
          &lt;attr name="pstsScrollOffset" format="dimension" /&gt;
          &lt;attr name="pstsTabBackground" format="reference" /&gt;
          &lt;attr name="pstsShouldExpand" format="boolean" /&gt;
          &lt;attr name="pstsTextAllCaps" format="boolean" /&gt;
      &lt;/declare-styleable&gt;
  </code></pre>