content: /*
   * Copyright (C) 2011 The Android Open Source Project
   * Copyright (C) 2011 Jake Wharton
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package viewpagerindicator;
  
  import android.content.Context;
  import android.support.v4.view.PagerAdapter;
  import android.support.v4.view.ViewPager;
  import android.support.v4.view.ViewPager.OnPageChangeListener;
  import android.util.AttributeSet;
  import android.view.View;
  import android.view.ViewGroup;
  import android.widget.HorizontalScrollView;
  import android.widget.LinearLayout;
  import android.widget.TextView;
  
  
  import com.cjj.bb.R;
  
  import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
  import static android.view.ViewGroup.LayoutParams.WRAP_CONTENT;
  
  /**
   * This widget implements the dynamic action bar tab behavior that can change
   * across different configurations or circumstances.
   */
  public class TabPageIndicator extends HorizontalScrollView implements PageIndicator {
      /** Title text used when no title is provided by the adapter. */
      private static final CharSequence EMPTY_TITLE = "";
  
      /**
       * Interface for a callback when the selected tab has been reselected.
       */
      public interface OnTabReselectedListener {
          /**
           * Callback when the selected tab has been reselected.
           *
           * @param position Position of the current center item.
           */
          void onTabReselected(int position);
      }
  
      private Runnable mTabSelector;
  
      private final OnClickListener mTabClickListener = new OnClickListener() {
          public void onClick(View view) {
              TabView tabView = (TabView)view;
              final int oldSelected = mViewPager.getCurrentItem();
              final int newSelected = tabView.getIndex();
              mViewPager.setCurrentItem(newSelected);
              if (oldSelected == newSelected && mTabReselectedListener != null) {
                  mTabReselectedListener.onTabReselected(newSelected);
              }
          }
      };
  
      private final IcsLinearLayout mTabLayout;
  
      private ViewPager mViewPager;
      private ViewPager.OnPageChangeListener mListener;
  
      private int mMaxTabWidth;
      private int mSelectedTabIndex;
  
      private OnTabReselectedListener mTabReselectedListener;
  
      public TabPageIndicator(Context context) {
          this(context, null);
      }
  
      public TabPageIndicator(Context context, AttributeSet attrs) {
          super(context, attrs);
          setHorizontalScrollBarEnabled(false);
  
          mTabLayout = new IcsLinearLayout(context, R.attr.vpiTabPageIndicatorStyle);
          addView(mTabLayout, new ViewGroup.LayoutParams(WRAP_CONTENT, MATCH_PARENT));
      }
  
      public void setOnTabReselectedListener(OnTabReselectedListener listener) {
          mTabReselectedListener = listener;
      }
  
      @Override
      public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
          final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
          final boolean lockedExpanded = widthMode == MeasureSpec.EXACTLY;
          setFillViewport(lockedExpanded);
  
          final int childCount = mTabLayout.getChildCount();
          if (childCount > 1 && (widthMode == MeasureSpec.EXACTLY || widthMode == MeasureSpec.AT_MOST)) {
              if (childCount > 2) {
                  mMaxTabWidth = (int)(MeasureSpec.getSize(widthMeasureSpec) * 0.4f);
              } else {
                  mMaxTabWidth = MeasureSpec.getSize(widthMeasureSpec) / 2;
              }
          } else {
              mMaxTabWidth = -1;
          }
  
          final int oldWidth = getMeasuredWidth();
          super.onMeasure(widthMeasureSpec, heightMeasureSpec);
          final int newWidth = getMeasuredWidth();
  
          if (lockedExpanded && oldWidth != newWidth) {
              // Recenter the tab display if we're at a new (scrollable) size.
              setCurrentItem(mSelectedTabIndex);
          }
      }
  
      private void animateToTab(final int position) {
          final View tabView = mTabLayout.getChildAt(position);
          if (mTabSelector != null) {
              removeCallbacks(mTabSelector);
          }
          mTabSelector = new Runnable() {
              public void run() {
                  final int scrollPos = tabView.getLeft() - (getWidth() - tabView.getWidth()) / 2;
                  smoothScrollTo(scrollPos, 0);
                  mTabSelector = null;
              }
          };
          post(mTabSelector);
      }
  
      @Override
      public void onAttachedToWindow() {
          super.onAttachedToWindow();
          if (mTabSelector != null) {
              // Re-post the selector we saved
              post(mTabSelector);
          }
      }
  
      @Override
      public void onDetachedFromWindow() {
          super.onDetachedFromWindow();
          if (mTabSelector != null) {
              removeCallbacks(mTabSelector);
          }
      }
  
      private void addTab(int index, CharSequence text, int iconResId) {
          final TabView tabView = new TabView(getContext());
          tabView.mIndex = index;
          tabView.setFocusable(true);
          tabView.setOnClickListener(mTabClickListener);
          tabView.setText(text);
  
          if (iconResId != 0) {
              tabView.setCompoundDrawablesWithIntrinsicBounds(iconResId, 0, 0, 0);
          }
  
          mTabLayout.addView(tabView, new LinearLayout.LayoutParams(0, MATCH_PARENT, 1));
      }
  
      @Override
      public void onPageScrollStateChanged(int arg0) {
          if (mListener != null) {
              mListener.onPageScrollStateChanged(arg0);
          }
      }
  
      @Override
      public void onPageScrolled(int arg0, float arg1, int arg2) {
          if (mListener != null) {
              mListener.onPageScrolled(arg0, arg1, arg2);
          }
      }
  
      @Override
      public void onPageSelected(int arg0) {
          setCurrentItem(arg0);
          if (mListener != null) {
              mListener.onPageSelected(arg0);
          }
      }
  
      @Override
      public void setViewPager(ViewPager view) {
          if (mViewPager == view) {
              return;
          }
          if (mViewPager != null) {
              mViewPager.setOnPageChangeListener(null);
          }
          final PagerAdapter adapter = view.getAdapter();
          if (adapter == null) {
              throw new IllegalStateException("ViewPager does not have adapter instance.");
          }
          mViewPager = view;
          view.setOnPageChangeListener(this);
          notifyDataSetChanged();
      }
  
      public void notifyDataSetChanged() {
          mTabLayout.removeAllViews();
          PagerAdapter adapter = mViewPager.getAdapter();
          IconPagerAdapter iconAdapter = null;
          if (adapter instanceof IconPagerAdapter) {
              iconAdapter = (IconPagerAdapter)adapter;
          }
          final int count = adapter.getCount();
          for (int i = 0; i < count; i++) {
              CharSequence title = adapter.getPageTitle(i);
              if (title == null) {
                  title = EMPTY_TITLE;
              }
              int iconResId = 0;
              if (iconAdapter != null) {
                  iconResId = iconAdapter.getIconResId(i);
              }
              addTab(i, title, iconResId);
          }
          if (mSelectedTabIndex > count) {
              mSelectedTabIndex = count - 1;
          }
          setCurrentItem(mSelectedTabIndex);
          requestLayout();
      }
  
      @Override
      public void setViewPager(ViewPager view, int initialPosition) {
          setViewPager(view);
          setCurrentItem(initialPosition);
      }
  
      @Override
      public void setCurrentItem(int item) {
          if (mViewPager == null) {
              throw new IllegalStateException("ViewPager has not been bound.");
          }
          mSelectedTabIndex = item;
          mViewPager.setCurrentItem(item);
  
          final int tabCount = mTabLayout.getChildCount();
          for (int i = 0; i < tabCount; i++) {
              final View child = mTabLayout.getChildAt(i);
              final boolean isSelected = (i == item);
              child.setSelected(isSelected);
              if (isSelected) {
                  animateToTab(item);
              }
          }
      }
  
      @Override
      public void setOnPageChangeListener(OnPageChangeListener listener) {
          mListener = listener;
      }
  
      private class TabView extends TextView {
          private int mIndex;
  
          public TabView(Context context) {
              super(context, null, R.attr.vpiTabPageIndicatorStyle);
          }
  
          @Override
          public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
              super.onMeasure(widthMeasureSpec, heightMeasureSpec);
  
              // Re-measure if we went beyond our maximum size.
              if (mMaxTabWidth > 0 && getMeasuredWidth() > mMaxTabWidth) {
                  super.onMeasure(MeasureSpec.makeMeasureSpec(mMaxTabWidth, MeasureSpec.EXACTLY),
                          heightMeasureSpec);
              }
          }
  
          public int getIndex() {
              return mIndex;
          }
      }
  }
  