content: /*
   * Copyright (C) 2012 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.content.res.Resources;
  import android.content.res.TypedArray;
  import android.graphics.Canvas;
  import android.graphics.Paint;
  import android.graphics.drawable.Drawable;
  import android.os.Parcel;
  import android.os.Parcelable;
  import android.support.v4.view.MotionEventCompat;
  import android.support.v4.view.ViewConfigurationCompat;
  import android.support.v4.view.ViewPager;
  import android.util.AttributeSet;
  import android.util.FloatMath;
  import android.view.MotionEvent;
  import android.view.View;
  import android.view.ViewConfiguration;
  
  import com.cjj.bb.R;
  
  /**
   * Draws a line for each page. The current page line is colored differently
   * than the unselected page lines.
   */
  public class LinePageIndicator extends View implements PageIndicator {
      private static final int INVALID_POINTER = -1;
  
      private final Paint mPaintUnselected = new Paint(Paint.ANTI_ALIAS_FLAG);
      private final Paint mPaintSelected = new Paint(Paint.ANTI_ALIAS_FLAG);
      private ViewPager mViewPager;
      private ViewPager.OnPageChangeListener mListener;
      private int mCurrentPage;
      private boolean mCentered;
      private float mLineWidth;
      private float mGapWidth;
  
      private int mTouchSlop;
      private float mLastMotionX = -1;
      private int mActivePointerId = INVALID_POINTER;
      private boolean mIsDragging;
  
  
      public LinePageIndicator(Context context) {
          this(context, null);
      }
  
      public LinePageIndicator(Context context, AttributeSet attrs) {
          this(context, attrs, R.attr.vpiLinePageIndicatorStyle);
      }
  
      public LinePageIndicator(Context context, AttributeSet attrs, int defStyle) {
          super(context, attrs, defStyle);
          if (isInEditMode()) return;
  
          final Resources res = getResources();
  
          //Load defaults from resources
          final int defaultSelectedColor = res.getColor(R.color.default_line_indicator_selected_color);
          final int defaultUnselectedColor = res.getColor(R.color.default_line_indicator_unselected_color);
          final float defaultLineWidth = res.getDimension(R.dimen.default_line_indicator_line_width);
          final float defaultGapWidth = res.getDimension(R.dimen.default_line_indicator_gap_width);
          final float defaultStrokeWidth = res.getDimension(R.dimen.default_line_indicator_stroke_width);
          final boolean defaultCentered = res.getBoolean(R.bool.default_line_indicator_centered);
  
          //Retrieve styles attributes
          TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.LinePageIndicator, defStyle, 0);
  
          mCentered = a.getBoolean(R.styleable.LinePageIndicator_centered, defaultCentered);
          mLineWidth = a.getDimension(R.styleable.LinePageIndicator_lineWidth, defaultLineWidth);
          mGapWidth = a.getDimension(R.styleable.LinePageIndicator_gapWidth, defaultGapWidth);
          setStrokeWidth(a.getDimension(R.styleable.LinePageIndicator_strokeWidth, defaultStrokeWidth));
          mPaintUnselected.setColor(a.getColor(R.styleable.LinePageIndicator_unselectedColor, defaultUnselectedColor));
          mPaintSelected.setColor(a.getColor(R.styleable.LinePageIndicator_selectedColor, defaultSelectedColor));
  
          Drawable background = a.getDrawable(R.styleable.LinePageIndicator_android_background);
          if (background != null) {
            setBackgroundDrawable(background);
          }
  
          a.recycle();
  
          final ViewConfiguration configuration = ViewConfiguration.get(context);
          mTouchSlop = ViewConfigurationCompat.getScaledPagingTouchSlop(configuration);
      }
  
  
      public void setCentered(boolean centered) {
          mCentered = centered;
          invalidate();
      }
  
      public boolean isCentered() {
          return mCentered;
      }
  
      public void setUnselectedColor(int unselectedColor) {
          mPaintUnselected.setColor(unselectedColor);
          invalidate();
      }
  
      public int getUnselectedColor() {
          return mPaintUnselected.getColor();
      }
  
      public void setSelectedColor(int selectedColor) {
          mPaintSelected.setColor(selectedColor);
          invalidate();
      }
  
      public int getSelectedColor() {
          return mPaintSelected.getColor();
      }
  
      public void setLineWidth(float lineWidth) {
          mLineWidth = lineWidth;
          invalidate();
      }
  
      public float getLineWidth() {
          return mLineWidth;
      }
  
      public void setStrokeWidth(float lineHeight) {
          mPaintSelected.setStrokeWidth(lineHeight);
          mPaintUnselected.setStrokeWidth(lineHeight);
          invalidate();
      }
  
      public float getStrokeWidth() {
          return mPaintSelected.getStrokeWidth();
      }
  
      public void setGapWidth(float gapWidth) {
          mGapWidth = gapWidth;
          invalidate();
      }
  
      public float getGapWidth() {
          return mGapWidth;
      }
  
      @Override
      protected void onDraw(Canvas canvas) {
          super.onDraw(canvas);
  
          if (mViewPager == null) {
              return;
          }
          final int count = mViewPager.getAdapter().getCount();
          if (count == 0) {
              return;
          }
  
          if (mCurrentPage >= count) {
              setCurrentItem(count - 1);
              return;
          }
  
          final float lineWidthAndGap = mLineWidth + mGapWidth;
          final float indicatorWidth = (count * lineWidthAndGap) - mGapWidth;
          final float paddingTop = getPaddingTop();
          final float paddingLeft = getPaddingLeft();
          final float paddingRight = getPaddingRight();
  
          float verticalOffset = paddingTop + ((getHeight() - paddingTop - getPaddingBottom()) / 2.0f);
          float horizontalOffset = paddingLeft;
          if (mCentered) {
              horizontalOffset += ((getWidth() - paddingLeft - paddingRight) / 2.0f) - (indicatorWidth / 2.0f);
          }
  
          //Draw stroked circles
          for (int i = 0; i < count; i++) {
              float dx1 = horizontalOffset + (i * lineWidthAndGap);
              float dx2 = dx1 + mLineWidth;
              canvas.drawLine(dx1, verticalOffset, dx2, verticalOffset, (i == mCurrentPage) ? mPaintSelected : mPaintUnselected);
          }
      }
  
      public boolean onTouchEvent(MotionEvent ev) {
          if (super.onTouchEvent(ev)) {
              return true;
          }
          if ((mViewPager == null) || (mViewPager.getAdapter().getCount() == 0)) {
              return false;
          }
  
          final int action = ev.getAction() & MotionEventCompat.ACTION_MASK;
          switch (action) {
              case MotionEvent.ACTION_DOWN:
                  mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
                  mLastMotionX = ev.getX();
                  break;
  
              case MotionEvent.ACTION_MOVE: {
                  final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);
                  final float x = MotionEventCompat.getX(ev, activePointerIndex);
                  final float deltaX = x - mLastMotionX;
  
                  if (!mIsDragging) {
                      if (Math.abs(deltaX) > mTouchSlop) {
                          mIsDragging = true;
                      }
                  }
  
                  if (mIsDragging) {
                      mLastMotionX = x;
                      if (mViewPager.isFakeDragging() || mViewPager.beginFakeDrag()) {
                          mViewPager.fakeDragBy(deltaX);
                      }
                  }
  
                  break;
              }
  
              case MotionEvent.ACTION_CANCEL:
              case MotionEvent.ACTION_UP:
                  if (!mIsDragging) {
                      final int count = mViewPager.getAdapter().getCount();
                      final int width = getWidth();
                      final float halfWidth = width / 2f;
                      final float sixthWidth = width / 6f;
  
                      if ((mCurrentPage > 0) && (ev.getX() < halfWidth - sixthWidth)) {
                          if (action != MotionEvent.ACTION_CANCEL) {
                              mViewPager.setCurrentItem(mCurrentPage - 1);
                          }
                          return true;
                      } else if ((mCurrentPage < count - 1) && (ev.getX() > halfWidth + sixthWidth)) {
                          if (action != MotionEvent.ACTION_CANCEL) {
                              mViewPager.setCurrentItem(mCurrentPage + 1);
                          }
                          return true;
                      }
                  }
  
                  mIsDragging = false;
                  mActivePointerId = INVALID_POINTER;
                  if (mViewPager.isFakeDragging()) mViewPager.endFakeDrag();
                  break;
  
              case MotionEventCompat.ACTION_POINTER_DOWN: {
                  final int index = MotionEventCompat.getActionIndex(ev);
                  mLastMotionX = MotionEventCompat.getX(ev, index);
                  mActivePointerId = MotionEventCompat.getPointerId(ev, index);
                  break;
              }
  
              case MotionEventCompat.ACTION_POINTER_UP:
                  final int pointerIndex = MotionEventCompat.getActionIndex(ev);
                  final int pointerId = MotionEventCompat.getPointerId(ev, pointerIndex);
                  if (pointerId == mActivePointerId) {
                      final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
                      mActivePointerId = MotionEventCompat.getPointerId(ev, newPointerIndex);
                  }
                  mLastMotionX = MotionEventCompat.getX(ev, MotionEventCompat.findPointerIndex(ev, mActivePointerId));
                  break;
          }
  
          return true;
      }
  
      @Override
      public void setViewPager(ViewPager viewPager) {
          if (mViewPager == viewPager) {
              return;
          }
          if (mViewPager != null) {
              //Clear us from the old pager.
              mViewPager.setOnPageChangeListener(null);
          }
          if (viewPager.getAdapter() == null) {
              throw new IllegalStateException("ViewPager does not have adapter instance.");
          }
          mViewPager = viewPager;
          mViewPager.setOnPageChangeListener(this);
          invalidate();
      }
  
      @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.");
          }
          mViewPager.setCurrentItem(item);
          mCurrentPage = item;
          invalidate();
      }
  
      @Override
      public void notifyDataSetChanged() {
          invalidate();
      }
  
      @Override
      public void onPageScrollStateChanged(int state) {
          if (mListener != null) {
              mListener.onPageScrollStateChanged(state);
          }
      }
  
      @Override
      public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
          if (mListener != null) {
              mListener.onPageScrolled(position, positionOffset, positionOffsetPixels);
          }
      }
  
      @Override
      public void onPageSelected(int position) {
          mCurrentPage = position;
          invalidate();
  
          if (mListener != null) {
              mListener.onPageSelected(position);
          }
      }
  
      @Override
      public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {
          mListener = listener;
      }
  
      @Override
      protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
          setMeasuredDimension(measureWidth(widthMeasureSpec), measureHeight(heightMeasureSpec));
      }
  
      /**
       * Determines the width of this view
       *
       * @param measureSpec
       *            A measureSpec packed into an int
       * @return The width of the view, honoring constraints from measureSpec
       */
      private int measureWidth(int measureSpec) {
          float result;
          int specMode = MeasureSpec.getMode(measureSpec);
          int specSize = MeasureSpec.getSize(measureSpec);
  
          if ((specMode == MeasureSpec.EXACTLY) || (mViewPager == null)) {
              //We were told how big to be
              result = specSize;
          } else {
              //Calculate the width according the views count
              final int count = mViewPager.getAdapter().getCount();
              result = getPaddingLeft() + getPaddingRight() + (count * mLineWidth) + ((count - 1) * mGapWidth);
              //Respect AT_MOST value if that was what is called for by measureSpec
              if (specMode == MeasureSpec.AT_MOST) {
                  result = Math.min(result, specSize);
              }
          }
          return (int)FloatMath.ceil(result);
      }
  
      /**
       * Determines the height of this view
       *
       * @param measureSpec
       *            A measureSpec packed into an int
       * @return The height of the view, honoring constraints from measureSpec
       */
      private int measureHeight(int measureSpec) {
          float result;
          int specMode = MeasureSpec.getMode(measureSpec);
          int specSize = MeasureSpec.getSize(measureSpec);
  
          if (specMode == MeasureSpec.EXACTLY) {
              //We were told how big to be
              result = specSize;
          } else {
              //Measure the height
              result = mPaintSelected.getStrokeWidth() + getPaddingTop() + getPaddingBottom();
              //Respect AT_MOST value if that was what is called for by measureSpec
              if (specMode == MeasureSpec.AT_MOST) {
                  result = Math.min(result, specSize);
              }
          }
          return (int)FloatMath.ceil(result);
      }
  
      @Override
      public void onRestoreInstanceState(Parcelable state) {
          SavedState savedState = (SavedState)state;
          super.onRestoreInstanceState(savedState.getSuperState());
          mCurrentPage = savedState.currentPage;
          requestLayout();
      }
  
      @Override
      public Parcelable onSaveInstanceState() {
          Parcelable superState = super.onSaveInstanceState();
          SavedState savedState = new SavedState(superState);
          savedState.currentPage = mCurrentPage;
          return savedState;
      }
  
      static class SavedState extends BaseSavedState {
          int currentPage;
  
          public SavedState(Parcelable superState) {
              super(superState);
          }
  
          private SavedState(Parcel in) {
              super(in);
              currentPage = in.readInt();
          }
  
          @Override
          public void writeToParcel(Parcel dest, int flags) {
              super.writeToParcel(dest, flags);
              dest.writeInt(currentPage);
          }
  
          @SuppressWarnings("UnusedDeclaration")
          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];
              }
          };
      }
  }