content: package im.actor.sdk.view;
  
  import android.annotation.SuppressLint;
  import android.content.Context;
  import android.content.res.TypedArray;
  import android.graphics.Canvas;
  import android.graphics.Color;
  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.FrameLayout;
  import android.widget.ImageButton;
  import android.widget.LinearLayout;
  import android.widget.TextView;
  
  import java.util.Locale;
  
  import im.actor.sdk.R;
  import im.actor.sdk.util.Screen;
  
  public class PagerSlidingTabStrip extends FrameLayout {
  
  
  
      public interface IconTabProvider {
          public int getPageIconResId(int position, Context context);
      }
      public interface TabProvider {
          public View getTab(int position, Context context);
      }
      // @formatter:off
      private static final int[] ATTRS = new int[]{
              android.R.attr.textSize,
              android.R.attr.textColor
      };
      // @formatter:on
  
      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 = 0xFFFFFFFF;
      private int underlineColor = 0x1A000000;
      private int dividerColor = 0x1A000000;
  
      private boolean textAllCaps = true;
  
      private int scrollOffset = 52;
      private int indicatorHeight = 8;
      private int underlineHeight = 2;
      private int dividerPadding = 12;
      private int tabPadding = Screen.dp(5);
      private int dividerWidth = 1;
  
      private int tabTextSize = 12;
      private int tabTextColor = 0xFFFFFFFF;
      private Typeface tabTypeface = null;
      private int tabTypefaceStyle = Typeface.BOLD;
      private int tabsContainerPaddingLeft = Screen.dp(11);
      private int tabsContainerPaddingTop = 0;
      private int tabsContainerPaddingRight = 0;
      private int tabsContainerPaddingBottom = 0;
  
      private int lastScrollX = 0;
  
      private int indicatorPadding = 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);
  
          setWillNotDraw(false);
  
          tabsContainer = new LinearLayout(context);
          tabsContainer.setOrientation(LinearLayout.HORIZONTAL);
          tabsContainer.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
          tabsContainer.setPadding(tabsContainerPaddingLeft, tabsContainerPaddingTop, tabsContainerPaddingRight, tabsContainerPaddingBottom);
          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);
          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);
  
          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();
  
          redrawTabs(pager.getCurrentItem());
      }
  
      public void setOnPageChangeListener(OnPageChangeListener listener) {
          this.delegatePageListener = listener;
      }
  
      public void notifyDataSetChanged() {
  
          tabsContainer.removeAllViews();
  
          tabCount = pager.getAdapter().getCount();
  
          for (int i = 0; i < tabCount; i++) {
  
              if (pager.getAdapter() instanceof IconTabProvider) {
                  if (((IconTabProvider) pager.getAdapter()).getPageIconResId(i, getContext()) != -1) {
                      addIconTab(i, ((IconTabProvider) pager.getAdapter()).getPageIconResId(i, getContext()));
                  } else {
                      addTextTab(i, pager.getAdapter().getPageTitle(i).toString());
                  }
              } else if(pager.getAdapter() instanceof TabProvider){
                  addTab(i, ((TabProvider)pager.getAdapter()).getTab(i, getContext()));
              } 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 < Build.VERSION_CODES.JELLY_BEAN) {
                      getViewTreeObserver().removeGlobalOnLayoutListener(this);
                  } else {
                      getViewTreeObserver().removeOnGlobalLayoutListener(this);
                  }
  
                  currentPosition = pager.getCurrentItem();
              }
          });
  
      }
  
      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, final View tab) {
          tab.setFocusable(true);
          tab.setOnClickListener(new OnClickListener() {
              @Override
              public void onClick(View v) {
                  pager.setCurrentItem(position);
              }
          });
          if(tabPadding>0)
              tab.setPadding(tabPadding, 0, tabPadding, 0);
          tabsContainer.addView(tab, position, expandedTabLayoutParams);
      }
  
      private void updateTabStyles() {
  
          for (int i = 0; i < 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
                  tab.setAllCaps(true);
  
              }
          }
  
      }
  
      @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() + indicatorPadding;
          float lineRight = currentTab.getRight() - indicatorPadding;
          int currentTabColor;
          int nextTabColor;
  
          // if there is an offset, start interpolating left and right coordinates between current and next tab
          if (currentPositionOffset > 0f && currentPosition < tabCount - 1) {
  
              View nextTab = tabsContainer.getChildAt(currentPosition + 1);
              final float nextTabLeft = nextTab.getLeft() + indicatorPadding;
              final float nextTabRight = nextTab.getRight() - indicatorPadding;
  
              lineLeft = (currentPositionOffset * nextTabLeft + (1f - currentPositionOffset) * lineLeft);
              lineRight = (currentPositionOffset * nextTabRight + (1f - currentPositionOffset) * lineRight);
  
              currentTabColor = blendColors(tabTextColor, 0x30000000, currentPositionOffset, false);
  
              nextTabColor = blendColors(tabTextColor, 0x30000000, currentPositionOffset, true);
  
              if (currentTab instanceof TextView) {
                  ((TextView) currentTab).setTextColor(currentTabColor);
              } else if (currentTab instanceof ImageButton) {
                  ((ImageButton) currentTab).setAlpha(Color.alpha(currentTabColor));
              }
  
              if (nextTab instanceof TextView) {
                  ((TextView) nextTab).setTextColor(nextTabColor);
              } else if (nextTab instanceof ImageButton) {
                  ((ImageButton) nextTab).setAlpha(Color.alpha(nextTabColor));
              }
          } else {
              for (int i = 0; i < tabCount; i++) {
                  if (tabsContainer.getChildAt(i) instanceof TextView) {
                      if (i == currentPosition) {
                          ((TextView) tabsContainer.getChildAt(i)).setTextColor(blendColors(tabTextColor, 0x30000000, currentPositionOffset, false));
                      } else {
                          ((TextView) tabsContainer.getChildAt(i)).setTextColor(blendColors(tabTextColor, 0x30000000, currentPositionOffset, true));
                      }
                  } else if (tabsContainer.getChildAt(i) instanceof ImageButton) {
                      if (i == currentPosition) {
                          ((ImageButton) tabsContainer.getChildAt(i)).setAlpha(Color.alpha(blendColors(tabTextColor, 0x30000000, currentPositionOffset, false)));
                      } else {
                          ((ImageButton) tabsContainer.getChildAt(i)).setAlpha(Color.alpha(blendColors(tabTextColor, 0x30000000, currentPositionOffset, true)));
                      }
                  }
              }
          }
  
  
          // canvas.drawRect(lineLeft, 0, lineRight, indicatorHeight, rectPaint);
          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 < tabCount - 1; i++) {
              View tab = tabsContainer.getChildAt(i);
              canvas.drawLine(tab.getRight(), dividerPadding, tab.getRight(), height - dividerPadding, dividerPaint);
          }
  
      }
  
      private static int blendColors(int color1, int color2, float ratio, boolean inverse) {
          final float inverseRation = 1f - ratio;
          float a = (Color.alpha(color1)) - (Color.alpha(color2) * (inverse ? inverseRation : ratio));
          float r = (Color.red(color1)) - (Color.red(color2) * (inverse ? inverseRation : ratio));
          float g = (Color.green(color1)) - (Color.green(color2) * (inverse ? inverseRation : ratio));
          float b = (Color.blue(color1)) - (Color.blue(color2) * (inverse ? inverseRation : ratio));
          return Color.argb((int) a, (int) r, (int) g, (int) b);
      }
  
      private class PageListener implements OnPageChangeListener {
  
          @Override
          public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
  
              currentPosition = position;
              currentPositionOffset = positionOffset;
  
              invalidate();
  
              if (delegatePageListener != null) {
                  delegatePageListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
              }
          }
  
          @Override
          public void onPageScrollStateChanged(int state) {
  
              if (delegatePageListener != null) {
                  delegatePageListener.onPageScrollStateChanged(state);
              }
          }
  
          @Override
          public void onPageSelected(int position) {
              redrawTabs(position);
              if (delegatePageListener != null) {
                  delegatePageListener.onPageSelected(position);
              }
          }
  
      }
  
      public void redrawTabs(int currentPosition) {
          try {
              for (int i = 0; i < tabsContainer.getChildCount(); ++i) {
                  View tmp = tabsContainer.getChildAt(i);
                  if (i == currentPosition) {
                      tmp.setSelected(true);
                  } else {
                      tmp.setSelected(false);
                  }
              }
          } catch (Exception e) {
              //no-op
          }
      }
  
      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 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;
      }
  
      public void setTabLayoutParams(LinearLayout.LayoutParams tabLayoutParams) {
          this.expandedTabLayoutParams = tabLayoutParams;
      }
  
      public int getIndicatorPadding() {
          return indicatorPadding;
      }
  
      public void setIndicatorPadding(int indicatorPadding) {
          this.indicatorPadding = indicatorPadding;
      }
  
      @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 Creator<SavedState> CREATOR = new Creator<SavedState>() {
              @Override
              public SavedState createFromParcel(Parcel in) {
                  return new SavedState(in);
              }
  
              @Override
              public SavedState[] newArray(int size) {
                  return new SavedState[size];
              }
          };
      }
  
  }
  