Java 类android.view.FocusFinder 实例源码

private boolean handleHorizontalFocusWithinListItem(int direction) {
    if (direction == 33 || direction == 130) {
        int numChildren = getChildCount();
        if (this.mItemsCanFocus && numChildren > 0 && this.mSelectedPosition != -1) {
            View selectedView = getSelectedView();
            if (selectedView != null && selectedView.hasFocus() && (selectedView instanceof ViewGroup)) {
                View currentFocus = selectedView.findFocus();
                View nextFocus = FocusFinder.getInstance().findNextFocus((ViewGroup) selectedView, currentFocus, direction);
                if (nextFocus != null) {
                    currentFocus.getFocusedRect(this.mTempRect);
                    offsetDescendantRectToMyCoords(currentFocus, this.mTempRect);
                    offsetRectIntoDescendantCoords(nextFocus, this.mTempRect);
                    if (nextFocus.requestFocus(direction, this.mTempRect)) {
                        return true;
                    }
                }
                View globalNextFocus = FocusFinder.getInstance().findNextFocus((ViewGroup) getRootView(), currentFocus, direction);
                if (globalNextFocus != null) {
                    return isViewAncestorOf(globalNextFocus, this);
                }
            }
        }
        return false;
    }
    throw new IllegalArgumentException("direction must be one of {View.FOCUS_UP, View.FOCUS_DOWN}");
}

/**
 * When looking for focus in children of a scroll view, need to be a little
 * more careful not to give focus to something that is scrolled off screen.
 * <p/>
 * This is more expensive than the default {@link android.view.ViewGroup}
 * implementation, otherwise this behavior might have been made the default.
 */
@Override
protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {
    // convert from forward / backward notation to up / down / left / right
    // (ugh).
    if (direction == View.FOCUS_FORWARD) {
        direction = View.FOCUS_DOWN;
    } else if (direction == View.FOCUS_BACKWARD) {
        direction = View.FOCUS_UP;
    }

    final View nextFocus = previouslyFocusedRect == null ?
            FocusFinder.getInstance().findNextFocus(this, null, direction) :
            FocusFinder.getInstance().findNextFocusFromRect(this,
                    previouslyFocusedRect, direction);

    if (nextFocus == null) {
        return false;
    }

    return nextFocus.requestFocus(direction, previouslyFocusedRect);
}

@Override
public View focusSearch(View focused, int direction) {
    View result = mLayout.onInterceptFocusSearch(focused, direction);
    if (result != null) {
        return result;
    }
    final FocusFinder ff = FocusFinder.getInstance();
    result = ff.findNextFocus(this, focused, direction);
    if (result == null && mAdapter != null && mLayout != null && !isComputingLayout()
            && !mLayoutFrozen) {
        eatRequestLayout();
        result = mLayout.onFocusSearchFailed(focused, direction, mRecycler, mState);
        resumeRequestLayout(false);
    }
    return result != null ? result : super.focusSearch(focused, direction);
}

protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {
    if (direction == 2) {
        direction = 130;
    } else if (direction == 1) {
        direction = 33;
    }
    View nextFocus = previouslyFocusedRect == null ? FocusFinder.getInstance().findNextFocus(this, null, direction) : FocusFinder.getInstance().findNextFocusFromRect(this, previouslyFocusedRect, direction);
    if (nextFocus == null || isOffScreen(nextFocus)) {
        return false;
    }
    return nextFocus.requestFocus(direction, previouslyFocusedRect);
}

/**
 * 获得滑动的方向
 */
public boolean arrowScroll(int direction) {
    View currentFocused = findFocus();
    if (currentFocused == this) currentFocused = null;

    boolean handled = false;

    View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused,
            direction);
    if (nextFocused != null && nextFocused != currentFocused) {
        if (direction == View.FOCUS_LEFT) {
            handled = nextFocused.requestFocus();
        } else if (direction == View.FOCUS_RIGHT) {
            // If there is nothing to the right, or this is causing us to
            // jump to the left, then what we really want to do is page right.
            if (currentFocused != null && nextFocused.getLeft() <= currentFocused.getLeft()) {
                handled = pageRight();
            } else {
                handled = nextFocused.requestFocus();
            }
        }
    } else if (direction == FOCUS_LEFT || direction == FOCUS_BACKWARD) {
        // Trying to move left and nothing there; try to page.
        handled = pageLeft();
    } else if (direction == FOCUS_RIGHT || direction == FOCUS_FORWARD) {
        // Trying to move right and nothing there; try to page.
        handled = pageRight();
    }
    if (handled) {
        playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction));
    }
    return handled;
}

/**
 * To avoid horizontal focus searches changing the selected item, we
 * manually focus search within the selected item (as applicable), and
 * prevent focus from jumping to something within another item.
 * 
 * @param direction
 *            one of {View.FOCUS_LEFT, View.FOCUS_RIGHT}
 * @return Whether this consumes the key event.
 */
private boolean handleHorizontalFocusWithinListItem(int direction) {
    // TODO: implement this
    if (direction != View.FOCUS_UP && direction != View.FOCUS_DOWN) {
        throw new IllegalArgumentException("direction must be one of" + " {View.FOCUS_UP, View.FOCUS_DOWN}");
    }

    final int numChildren = getChildCount();
    if (mItemsCanFocus && numChildren > 0 && mSelectedPosition != INVALID_POSITION) {
        final View selectedView = getSelectedView();
        if (selectedView != null && selectedView.hasFocus() && selectedView instanceof ViewGroup) {

            final View currentFocus = selectedView.findFocus();
            final View nextFocus = FocusFinder.getInstance().findNextFocus((ViewGroup) selectedView, currentFocus,
                    direction);
            if (nextFocus != null) {
                // do the math to get interesting rect in next focus'
                // coordinates
                currentFocus.getFocusedRect(mTempRect);
                offsetDescendantRectToMyCoords(currentFocus, mTempRect);
                offsetRectIntoDescendantCoords(nextFocus, mTempRect);
                if (nextFocus.requestFocus(direction, mTempRect)) {
                    return true;
                }
            }
            // we are blocking the key from being handled (by returning
            // true)
            // if the global result is going to be some other view within
            // this
            // list. this is to acheive the overall goal of having
            // horizontal d-pad navigation remain in the current item.
            final View globalNextFocus = FocusFinder.getInstance().findNextFocus((ViewGroup) getRootView(),
                    currentFocus, direction);
            if (globalNextFocus != null) {
                return isViewAncestorOf(globalNextFocus, this);
            }
        }
    }
    return false;
}

@Override
public View focusSearch(View focused, int direction) {
    View result = mLayout.onInterceptFocusSearch(focused, direction);
    if (result != null) {
        return result;
    }
    final FocusFinder ff = FocusFinder.getInstance();
    result = ff.findNextFocus(this, focused, direction);
    if (result == null && mAdapter != null && mLayout != null && !isComputingLayout()
            && !mLayoutFrozen) {
        eatRequestLayout();
        result = mLayout.onFocusSearchFailed(focused, direction, mRecycler, mState);
        resumeRequestLayout(false);
    }
    return result != null ? result : super.focusSearch(focused, direction);
}

public boolean arrowScroll(int direction) {
    View currentFocused = findFocus();
    if (currentFocused == this) currentFocused = null;

    boolean handled = false;

    View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused,
            direction);
    if (nextFocused != null && nextFocused != currentFocused) {
        if (direction == View.FOCUS_LEFT) {
            handled = nextFocused.requestFocus();
        } else if (direction == View.FOCUS_RIGHT) {
            // If there is nothing to the right, or this is causing us to
            // jump to the left, then what we really want to do is page right.
            if (currentFocused != null && nextFocused.getLeft() <= currentFocused.getLeft()) {
                handled = pageRight();
            } else {
                handled = nextFocused.requestFocus();
            }
        }
    } else if (direction == FOCUS_LEFT || direction == FOCUS_BACKWARD) {
        // Trying to move left and nothing there; try to page.
        handled = pageLeft();
    } else if (direction == FOCUS_RIGHT || direction == FOCUS_FORWARD) {
        // Trying to move right and nothing there; try to page.
        handled = pageRight();
    }
    if (handled) {
        playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction));
    }
    return handled;
}

public boolean arrowScroll(int direction) {
    View currentFocused = findFocus();
    if (currentFocused == this) currentFocused = null;

    boolean handled = false;

    View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused,
            direction);
    if (nextFocused != null && nextFocused != currentFocused) {
        if (direction == View.FOCUS_LEFT) {
            handled = nextFocused.requestFocus();
        } else if (direction == View.FOCUS_RIGHT) {
            // If there is nothing to the right, or this is causing us to
            // jump to the left, then what we really want to do is page right.
            if (currentFocused != null && nextFocused.getLeft() <= currentFocused.getLeft()) {
                handled = pageRight();
            } else {
                handled = nextFocused.requestFocus();
            }
        }
    } else if (direction == FOCUS_LEFT || direction == FOCUS_BACKWARD) {
        // Trying to move left and nothing there; try to page.
        handled = pageLeft();
    } else if (direction == FOCUS_RIGHT || direction == FOCUS_FORWARD) {
        // Trying to move right and nothing there; try to page.
        handled = pageRight();
    }
    if (handled) {
        playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction));
    }
    return handled;
}

public boolean arrowScroll(int direction) {
    View currentFocused = findFocus();
    if (currentFocused == this) currentFocused = null;

    boolean handled = false;

    View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused,
            direction);
    if (nextFocused != null && nextFocused != currentFocused) {
        if (direction == View.FOCUS_LEFT) {
            handled = nextFocused.requestFocus();
        } else if (direction == View.FOCUS_RIGHT) {
            // If there is nothing to the right, or this is causing us to
            // jump to the left, then what we really want to do is page right.
            if (currentFocused != null && nextFocused.getLeft() <= currentFocused.getLeft()) {
                handled = pageRight();
            } else {
                handled = nextFocused.requestFocus();
            }
        }
    } else if (direction == FOCUS_LEFT || direction == FOCUS_BACKWARD) {
        // Trying to move left and nothing there; try to page.
        handled = pageLeft();
    } else if (direction == FOCUS_RIGHT || direction == FOCUS_FORWARD) {
        // Trying to move right and nothing there; try to page.
        handled = pageRight();
    }
    if (handled) {
        playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction));
    }
    return handled;
}

/**
 * When looking for focus in children of a scroll view, need to be a little
 * more careful not to give focus to something that is scrolled off screen.
 * <p>
 * This is more expensive than the default {@link android.view.ViewGroup}
 * implementation, otherwise this behavior might have been made the default.
 */
@Override
protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect)
{
    // convert from forward / backward notation to up / down / left / right
    // (ugh).
    if (direction == View.FOCUS_FORWARD)
    {
        direction = View.FOCUS_DOWN;
    } else if (direction == View.FOCUS_BACKWARD)
    {
        direction = View.FOCUS_UP;
    }

    final View nextFocus = previouslyFocusedRect == null ?
            FocusFinder.getInstance().findNextFocus(this, null, direction) :
            FocusFinder.getInstance().findNextFocusFromRect(this,
                    previouslyFocusedRect, direction);

    return nextFocus != null && nextFocus.requestFocus(direction, previouslyFocusedRect);
}

/**
 * When looking for focus in children of a scroll view, need to be a little
 * more careful not to give focus to something that is scrolled off screen.
 * <p/>
 * This is more expensive than the default {@link ViewGroup}
 * implementation, otherwise this behavior might have been made the default.
 */
@Override
protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {

    // convert from forward / backward notation to up / down / left / right
    // (ugh).
    if (direction == View.FOCUS_FORWARD) {
        direction = View.FOCUS_DOWN;
    } else if (direction == View.FOCUS_BACKWARD) {
        direction = View.FOCUS_UP;
    }

    final View nextFocus = previouslyFocusedRect == null ? FocusFinder.getInstance().findNextFocus(this, null,
            direction) : FocusFinder.getInstance().findNextFocusFromRect(this, previouslyFocusedRect, direction);

    if (nextFocus == null) {
        return false;
    }

    if (isOffScreen(nextFocus)) {
        return false;
    }

    return nextFocus.requestFocus(direction, previouslyFocusedRect);
}

/**
 * When looking for focus in children of a scroll view, need to be a little
 * more careful not to give focus to something that is scrolled off screen.
 * <p/>
 * This is more expensive than the default {@link ViewGroup}
 * implementation, otherwise this behavior might have been made the default.
 */
@Override
protected boolean onRequestFocusInDescendants(int direction, @Nullable Rect previouslyFocusedRect) {

    // convert from forward / backward notation to up / down / left / right
    // (ugh).
    if (direction == View.FOCUS_FORWARD) {
        direction = View.FOCUS_DOWN;
    } else if (direction == View.FOCUS_BACKWARD) {
        direction = View.FOCUS_UP;
    }

    View nextFocus = (previouslyFocusedRect == null) ? FocusFinder.getInstance().findNextFocus(this, null, direction) : FocusFinder.getInstance().findNextFocusFromRect(this, previouslyFocusedRect, direction);

    if (nextFocus == null) {
        return false;
    }

    return !isOffScreen(nextFocus) && nextFocus.requestFocus(direction, previouslyFocusedRect);

}

/**
 * When looking for focus in children of a scroll view, need to be a little
 * more careful not to give focus to something that is scrolled off screen.
 * <p/>
 * This is more expensive than the default {@link android.view.ViewGroup}
 * implementation, otherwise this behavior might have been made the default.
 */
@Override
protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {
    // convert from forward / backward notation to up / down / left / right
    // (ugh).
    if (direction == View.FOCUS_FORWARD) {
        direction = View.FOCUS_DOWN;
    } else if (direction == View.FOCUS_BACKWARD) {
        direction = View.FOCUS_UP;
    }

    final View nextFocus = previouslyFocusedRect == null ?
            FocusFinder.getInstance().findNextFocus(this, null, direction) :
            FocusFinder.getInstance().findNextFocusFromRect(this,
                    previouslyFocusedRect, direction);

    if (nextFocus == null) {
        return false;
    }

    return nextFocus.requestFocus(direction, previouslyFocusedRect);
}

/**
 * When looking for focus in children of a scroll view, need to be a little
 * more careful not to give focus to something that is scrolled off screen.
 *
 * This is more expensive than the default {@link ViewGroup}
 * implementation, otherwise this behavior might have been made the default.
 */
@Override
protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {
 // convert from forward / backward notation to up / down / left / right
 // (ugh).
 if (direction == View.FOCUS_FORWARD) {
     direction = View.FOCUS_DOWN;
 } else if (direction == View.FOCUS_BACKWARD) {
     direction = View.FOCUS_UP;
 }

 final View nextFocus = previouslyFocusedRect == null ?
         FocusFinder.getInstance().findNextFocus(this, null, direction) :
             FocusFinder.getInstance().findNextFocusFromRect(this,
                     previouslyFocusedRect, direction);

         if (nextFocus == null) {
             return false;
         }

         return nextFocus.requestFocus(direction, previouslyFocusedRect);
}

/**
 * When looking for focus in children of a scroll view, need to be a little
 * more careful not to give focus to something that is scrolled off screen.
 * <p/>
 * This is more expensive than the default {@link android.view.ViewGroup}
 * implementation, otherwise this behavior might have been made the default.
 */
@Override
protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {
    // convert from forward / backward notation to up / down / left / right
    // (ugh).
    if (direction == View.FOCUS_FORWARD) {
        direction = View.FOCUS_DOWN;
    } else if (direction == View.FOCUS_BACKWARD) {
        direction = View.FOCUS_UP;
    }

    final View nextFocus = previouslyFocusedRect == null ?
            FocusFinder.getInstance().findNextFocus(this, null, direction) :
            FocusFinder.getInstance().findNextFocusFromRect(this,
                    previouslyFocusedRect, direction);

    if (nextFocus == null) {
        return false;
    }

    return nextFocus.requestFocus(direction, previouslyFocusedRect);
}

public View focusSearch(View paramView, int paramInt)
{
  View localView1 = this.mLayout.onInterceptFocusSearch(paramView, paramInt);
  if (localView1 != null) {
    return localView1;
  }
  View localView2 = FocusFinder.getInstance().findNextFocus(this, paramView, paramInt);
  if ((localView2 == null) && (this.mAdapter != null) && (this.mLayout != null) && (!isComputingLayout()) && (!this.mLayoutFrozen))
  {
    eatRequestLayout();
    localView2 = this.mLayout.onFocusSearchFailed$1539f5dc(paramInt, this.mRecycler, this.mState);
    resumeRequestLayout(false);
  }
  if (localView2 != null) {
    return localView2;
  }
  return super.focusSearch(paramView, paramInt);
}

public View focusSearch(View paramView, int paramInt)
{
  View localView = FocusFinder.getInstance().findNextFocus(this, paramView, paramInt);
  if ((localView == null) && (this.g != null) && (this.h != null)) {
    if (this.r <= 0) {
      break label82;
    }
  }
  label82:
  for (int i1 = 1;; i1 = 0)
  {
    if ((i1 == 0) && (!this.n))
    {
      a();
      localView = this.h.c(paramInt, this.b, this.y);
      a(false);
    }
    if (localView == null) {
      break;
    }
    return localView;
  }
  return super.focusSearch(paramView, paramInt);
}

/**
 * When looking for focus in children of a scroll view, need to be a little
 * more careful not to give focus to something that is scrolled off screen.
 * <p/>
 * This is more expensive than the default {@link ViewGroup}
 * implementation, otherwise this behavior might have been made the default.
 */
@Override
protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {

    // convert from forward / backward notation to up / down / left / right
    // (ugh).
    if (direction == View.FOCUS_FORWARD) {
        direction = View.FOCUS_DOWN;
    } else if (direction == View.FOCUS_BACKWARD) {
        direction = View.FOCUS_UP;
    }

    final View nextFocus = previouslyFocusedRect == null ? FocusFinder.getInstance().findNextFocus(this, null, direction) : FocusFinder
            .getInstance().findNextFocusFromRect(this, previouslyFocusedRect, direction);

    if (nextFocus == null) {
        return false;
    }

    if (isOffScreen(nextFocus)) {
        return false;
    }

    return nextFocus.requestFocus(direction, previouslyFocusedRect);
}

/**
 * When looking for focus in children of a scroll view, need to be a little
 * more careful not to give focus to something that is scrolled off screen.
 * <p/>
 * This is more expensive than the default {@link ViewGroup}
 * implementation, otherwise this behavior might have been made the default.
 */
@Override
protected boolean onRequestFocusInDescendants(int direction, @Nullable Rect previouslyFocusedRect) {

    // convert from forward / backward notation to up / down / left / right
    // (ugh).
    if (direction == View.FOCUS_FORWARD) {
        direction = View.FOCUS_DOWN;
    } else if (direction == View.FOCUS_BACKWARD) {
        direction = View.FOCUS_UP;
    }

    View nextFocus = (previouslyFocusedRect == null) ? FocusFinder.getInstance().findNextFocus(this, null, direction) : FocusFinder.getInstance().findNextFocusFromRect(this, previouslyFocusedRect, direction);

    if (nextFocus == null) {
        return false;
    }

    return !isOffScreen(nextFocus) && nextFocus.requestFocus(direction, previouslyFocusedRect);

}

/**
 * When looking for focus in children of a scroll view, need to be a little
 * more careful not to give focus to something that is scrolled off screen.
 * <p/>
 * This is more expensive than the default {@link ViewGroup}
 * implementation, otherwise this behavior might have been made the default.
 */
@Override
protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {

    // convert from forward / backward notation to up / down / left / right
    // (ugh).
    if (direction == View.FOCUS_FORWARD) {
        direction = View.FOCUS_DOWN;
    } else if (direction == View.FOCUS_BACKWARD) {
        direction = View.FOCUS_UP;
    }

    final View nextFocus = previouslyFocusedRect == null ? FocusFinder.getInstance().findNextFocus(this, null, direction) : FocusFinder
            .getInstance().findNextFocusFromRect(this, previouslyFocusedRect, direction);

    if (nextFocus == null) {
        return false;
    }

    if (isOffScreen(nextFocus)) {
        return false;
    }

    return nextFocus.requestFocus(direction, previouslyFocusedRect);
}

@Override
protected void setUp() throws Exception {
    super.setUp();

    mFocusFinder = FocusFinder.getInstance();

    // inflate the layout
    final Context context = getContext();
    final LayoutInflater inflater = LayoutInflater.from(context);
    mRoot = (ViewGroup) inflater.inflate(R.layout.focus_2, null);

    // manually measure it, and lay it out
    mRoot.measure(500, 500);
    mRoot.layout(0, 0, 500, 500);

    mLeftButton = (Button) mRoot.findViewById(R.id.leftButton);
    mCenterButton = (Button) mRoot.findViewById(R.id.centerButton);
    mRightButton = (Button) mRoot.findViewById(R.id.rightButton);
}

/**
 * When looking for focus in children of a scroll view, need to be a little
 * more careful not to give focus to something that is scrolled off screen.
 *
 * This is more expensive than the default {@link android.view.ViewGroup}
 * implementation, otherwise this behavior might have been made the default.
 */
@Override
protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {
 // convert from forward / backward notation to up / down / left / right
 // (ugh).
 if (direction == View.FOCUS_FORWARD) {
     direction = View.FOCUS_DOWN;
 } else if (direction == View.FOCUS_BACKWARD) {
     direction = View.FOCUS_UP;
 }

 final View nextFocus = previouslyFocusedRect == null ?
         FocusFinder.getInstance().findNextFocus(this, null, direction) :
             FocusFinder.getInstance().findNextFocusFromRect(this,
                     previouslyFocusedRect, direction);

         if (nextFocus == null) {
             return false;
         }

         return nextFocus.requestFocus(direction, previouslyFocusedRect);
}

@Override
protected void setUp() throws Exception {
    super.setUp();

    mFocusFinder = FocusFinder.getInstance();

    // inflate the layout
    final Context context = getContext();
    final LayoutInflater inflater = LayoutInflater.from(context);
    mRoot = (ViewGroup) inflater.inflate(R.layout.focus_2, null);

    // manually measure it, and lay it out
    mRoot.measure(500, 500);
    mRoot.layout(0, 0, 500, 500);

    mLeftButton = (Button) mRoot.findViewById(R.id.leftButton);
    mCenterButton = (Button) mRoot.findViewById(R.id.centerButton);
    mRightButton = (Button) mRoot.findViewById(R.id.rightButton);
}

@Override
protected void setUp() throws Exception {
    super.setUp();

    mFocusFinder = FocusFinder.getInstance();

    // inflate the layout
    final Context context = getContext();
    final LayoutInflater inflater = LayoutInflater.from(context);
    mRoot = (ViewGroup) inflater.inflate(R.layout.focus_2, null);

    // manually measure it, and lay it out
    mRoot.measure(500, 500);
    mRoot.layout(0, 0, 500, 500);

    mLeftButton = (Button) mRoot.findViewById(R.id.leftButton);
    mCenterButton = (Button) mRoot.findViewById(R.id.centerButton);
    mRightButton = (Button) mRoot.findViewById(R.id.rightButton);
}

@Override
protected void setUp() throws Exception {
    super.setUp();

    mFocusFinder = FocusFinder.getInstance();

    // inflate the layout
    final Context context = getContext();
    final LayoutInflater inflater = LayoutInflater.from(context);
    mRoot = (ViewGroup) inflater.inflate(R.layout.focus_2, null);

    // manually measure it, and lay it out
    mRoot.measure(500, 500);
    mRoot.layout(0, 0, 500, 500);

    mLeftButton = (Button) mRoot.findViewById(R.id.leftButton);
    mCenterButton = (Button) mRoot.findViewById(R.id.centerButton);
    mRightButton = (Button) mRoot.findViewById(R.id.rightButton);
}

@Override
protected void setUp() throws Exception {
    super.setUp();

    mFocusFinder = FocusFinder.getInstance();

    // inflate the layout
    final Context context = getContext();
    final LayoutInflater inflater = LayoutInflater.from(context);
    mRoot = (ViewGroup) inflater.inflate(R.layout.focus_2, null);

    // manually measure it, and lay it out
    mRoot.measure(500, 500);
    mRoot.layout(0, 0, 500, 500);

    mLeftButton = (Button) mRoot.findViewById(R.id.leftButton);
    mCenterButton = (Button) mRoot.findViewById(R.id.centerButton);
    mRightButton = (Button) mRoot.findViewById(R.id.rightButton);
}

@Override
protected void setUp() throws Exception {
    super.setUp();

    mFocusFinder = FocusFinder.getInstance();

    // inflate the layout
    final Context context = getContext();
    final LayoutInflater inflater = LayoutInflater.from(context);
    mRoot = (ViewGroup) inflater.inflate(R.layout.focus_2, null);

    // manually measure it, and lay it out
    mRoot.measure(500, 500);
    mRoot.layout(0, 0, 500, 500);

    mLeftButton = (Button) mRoot.findViewById(R.id.leftButton);
    mCenterButton = (Button) mRoot.findViewById(R.id.centerButton);
    mRightButton = (Button) mRoot.findViewById(R.id.rightButton);
}

@Override
protected void setUp() throws Exception {
    super.setUp();

    mFocusFinder = FocusFinder.getInstance();

    // inflate the layout
    final Context context = getContext();
    final LayoutInflater inflater = LayoutInflater.from(context);
    mRoot = (ViewGroup) inflater.inflate(R.layout.focus_2, null);

    // manually measure it, and lay it out
    mRoot.measure(500, 500);
    mRoot.layout(0, 0, 500, 500);

    mLeftButton = (Button) mRoot.findViewById(R.id.leftButton);
    mCenterButton = (Button) mRoot.findViewById(R.id.centerButton);
    mRightButton = (Button) mRoot.findViewById(R.id.rightButton);
}

public boolean arrowScroll(int direction) {
    View currentFocused = findFocus();
    if (currentFocused == this) {
        currentFocused = null;
    } else if (currentFocused != null) {
        boolean isChild = false;
        for (ViewParent parent = currentFocused.getParent(); parent instanceof ViewGroup;
             parent = parent.getParent()) {
            if (parent == this) {
                isChild = true;
                break;
            }
        }
        if (!isChild) {
            // This would cause the focus search down below to fail in fun ways.
            final StringBuilder sb = new StringBuilder();
            sb.append(currentFocused.getClass().getSimpleName());
            for (ViewParent parent = currentFocused.getParent(); parent instanceof ViewGroup;
                 parent = parent.getParent()) {
                sb.append(" => ").append(parent.getClass().getSimpleName());
            }
            Log.e(TAG, "arrowScroll tried to find focus based on non-child " +
                    "current focused view " + sb.toString());
            currentFocused = null;
        }
    }

    boolean handled = false;

    View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused,
            direction);
    if (nextFocused != null && nextFocused != currentFocused) {
        if (direction == View.FOCUS_UP) {
            // If there is nothing to the left, or this is causing us to
            // jump to the right, then what we really want to do is page left.
            final int nextTop = getChildRectInPagerCoordinates(mTempRect, nextFocused).top;
            final int currTop = getChildRectInPagerCoordinates(mTempRect, currentFocused).top;
            if (currentFocused != null && nextTop >= currTop) {
                handled = pageUp();
            } else {
                handled = nextFocused.requestFocus();
            }
        } else if (direction == View.FOCUS_DOWN) {
            // If there is nothing to the right, or this is causing us to
            // jump to the left, then what we really want to do is page right.
            final int nextDown = getChildRectInPagerCoordinates(mTempRect, nextFocused).bottom;
            final int currDown = getChildRectInPagerCoordinates(mTempRect, currentFocused).bottom;
            if (currentFocused != null && nextDown <= currDown) {
                handled = pageDown();
            } else {
                handled = nextFocused.requestFocus();
            }
        }
    } else if (direction == FOCUS_UP || direction == FOCUS_BACKWARD) {
        // Trying to move left and nothing there; try to page.
        handled = pageUp();
    } else if (direction == FOCUS_DOWN || direction == FOCUS_FORWARD) {
        // Trying to move right and nothing there; try to page.
        handled = pageDown();
    }
    if (handled) {
        playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction));
    }
    return handled;
}

/**
 * 找到下一个焦点的itemView
 *
 * @param focusView
 * @param vector
 * @param direction
 * @return
 */
private boolean findNextFocusView(View focusView, Point vector, int direction) {
    View nextFocus = FocusFinder.getInstance()
            .findNextFocus(this, focusView, direction);
    //  Log.i(TAG, "right is null:" + (rightView == null));
    if (nextFocus != null) {
        nextFocus.requestFocus();
        return true;
    } else {
        this.smoothScrollBy(vector.x, vector.y);
        return true;
    }
}

/**
 * Handle scrolling in response to a left or right arrow click.
 *
 * @param direction The direction corresponding to the arrow key that was pressed. It should be
 *                  either {@link View#FOCUS_LEFT} or {@link View#FOCUS_RIGHT}.
 * @return Whether the scrolling was handled successfully.
 */
public boolean arrowScroll(int direction) {
    View currentFocused = findFocus();
    if (currentFocused == this) {
        currentFocused = null;
    } else if (currentFocused != null) {
        boolean isChild = false;
        for (ViewParent parent = currentFocused.getParent(); parent instanceof ViewGroup;
             parent = parent.getParent()) {
            if (parent == this) {
                isChild = true;
                break;
            }
        }
        if (!isChild) {
            // This would cause the focus search down below to fail in fun ways.
            final StringBuilder sb = new StringBuilder();
            sb.append(currentFocused.getClass().getSimpleName());
            for (ViewParent parent = currentFocused.getParent(); parent instanceof ViewGroup;
                 parent = parent.getParent()) {
                sb.append(" => ").append(parent.getClass().getSimpleName());
            }
            Log.e(TAG, "arrowScroll tried to find focus based on non-child "
                    + "current focused view " + sb.toString());
            currentFocused = null;
        }
    }

    boolean handled = false;

    View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused,
            direction);
    if (nextFocused != null && nextFocused != currentFocused) {
        if (direction == View.FOCUS_UP) {
            // If there is nothing to the left, or this is causing us to
            // jump to the right, then what we really want to do is page left.
            final int nextTop = getChildRectInPagerCoordinates(mTempRect, nextFocused).top;
            final int currTop = getChildRectInPagerCoordinates(mTempRect, currentFocused).top;
            if (currentFocused != null && nextTop >= currTop) {
                handled = pageUp();
            } else {
                handled = nextFocused.requestFocus();
            }
        } else if (direction == View.FOCUS_DOWN) {
            // If there is nothing to the right, or this is causing us to
            // jump to the left, then what we really want to do is page right.
            final int nextDown = getChildRectInPagerCoordinates(mTempRect, nextFocused).bottom;
            final int currDown = getChildRectInPagerCoordinates(mTempRect, currentFocused).bottom;
            if (currentFocused != null && nextDown <= currDown) {
                handled = pageDown();
            } else {
                handled = nextFocused.requestFocus();
            }
        }
    } else if (direction == FOCUS_UP || direction == FOCUS_BACKWARD) {
        // Trying to move left and nothing there; try to page.
        handled = pageUp();
    } else if (direction == FOCUS_DOWN || direction == FOCUS_FORWARD) {
        // Trying to move right and nothing there; try to page.
        handled = pageDown();
    }
    if (handled) {
        playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction));
    }
    return handled;
}

private ArrowScrollFocusResult arrowScrollFocused(int direction) {
    View newFocus;
    View selectedView = getSelectedView();
    if (selectedView == null || !selectedView.hasFocus()) {
        int xSearchPoint;
        if (direction == 130) {
            int listLeft = this.mListPadding.left + (this.mFirstPosition > 0 ? getArrowScrollPreviewLength() : 0);
            if (selectedView == null || selectedView.getLeft() <= listLeft) {
                xSearchPoint = listLeft;
            } else {
                xSearchPoint = selectedView.getLeft();
            }
            this.mTempRect.set(xSearchPoint, 0, xSearchPoint, 0);
        } else {
            int listRight = (getWidth() - this.mListPadding.right) - ((this.mFirstPosition + getChildCount()) + -1 < this.mItemCount ? getArrowScrollPreviewLength() : 0);
            if (selectedView == null || selectedView.getRight() >= listRight) {
                xSearchPoint = listRight;
            } else {
                xSearchPoint = selectedView.getRight();
            }
            this.mTempRect.set(xSearchPoint, 0, xSearchPoint, 0);
        }
        newFocus = FocusFinder.getInstance().findNextFocusFromRect(this, this.mTempRect, direction);
    } else {
        newFocus = FocusFinder.getInstance().findNextFocus(this, selectedView.findFocus(), direction);
    }
    if (newFocus != null) {
        int positionOfNewFocus = positionOfNewFocus(newFocus);
        if (!(this.mSelectedPosition == -1 || positionOfNewFocus == this.mSelectedPosition)) {
            int selectablePosition = lookForSelectablePositionOnScreen(direction);
            if (selectablePosition != -1 && ((direction == 130 && selectablePosition < positionOfNewFocus) || (direction == 33 && selectablePosition > positionOfNewFocus))) {
                return null;
            }
        }
        int focusScroll = amountToScrollToNewFocus(direction, newFocus, positionOfNewFocus);
        int maxScrollAmount = getMaxScrollAmount();
        if (focusScroll < maxScrollAmount) {
            newFocus.requestFocus(direction);
            this.mArrowScrollFocusResult.populate(positionOfNewFocus, focusScroll);
            return this.mArrowScrollFocusResult;
        } else if (distanceToView(newFocus) < maxScrollAmount) {
            newFocus.requestFocus(direction);
            this.mArrowScrollFocusResult.populate(positionOfNewFocus, maxScrollAmount);
            return this.mArrowScrollFocusResult;
        }
    }
    return null;
}

public View focusSearch(View focused, int direction) {
    View result = this.mLayout.onInterceptFocusSearch(focused, direction);
    if (result != null) {
        return result;
    }
    result = FocusFinder.getInstance().findNextFocus(this, focused, direction);
    if (!(result != null || this.mAdapter == null || this.mLayout == null || isComputingLayout() || this.mLayoutFrozen)) {
        eatRequestLayout();
        result = this.mLayout.onFocusSearchFailed(focused, direction, this.mRecycler, this.mState);
        resumeRequestLayout(false);
    }
    return result != null ? result : super.focusSearch(focused, direction);
}

public boolean arrowScroll(int direction) {
    View currentFocused = findFocus();
    if (currentFocused == this) {
        currentFocused = null;
    } else if (currentFocused != null) {
        boolean isChild = false;
        for (ViewPager parent = currentFocused.getParent(); parent instanceof ViewGroup; parent = parent.getParent()) {
            if (parent == this) {
                isChild = true;
                break;
            }
        }
        if (!isChild) {
            StringBuilder sb = new StringBuilder();
            sb.append(currentFocused.getClass().getSimpleName());
            for (ViewParent parent2 = currentFocused.getParent(); parent2 instanceof ViewGroup; parent2 = parent2.getParent()) {
                sb.append(" => ").append(parent2.getClass().getSimpleName());
            }
            Log.e(TAG, "arrowScroll tried to find focus based on non-child current focused view " + sb.toString());
            currentFocused = null;
        }
    }
    boolean handled = false;
    View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, direction);
    if (nextFocused == null || nextFocused == currentFocused) {
        if (direction == 17 || direction == 1) {
            handled = pageLeft();
        } else if (direction == 66 || direction == 2) {
            handled = pageRight();
        }
    } else if (direction == 17) {
        handled = (currentFocused == null || getChildRectInPagerCoordinates(this.mTempRect, nextFocused).left < getChildRectInPagerCoordinates(this.mTempRect, currentFocused).left) ? nextFocused.requestFocus() : pageLeft();
    } else if (direction == 66) {
        handled = (currentFocused == null || getChildRectInPagerCoordinates(this.mTempRect, nextFocused).left > getChildRectInPagerCoordinates(this.mTempRect, currentFocused).left) ? nextFocused.requestFocus() : pageRight();
    }
    if (handled) {
        playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction));
    }
    return handled;
}

public boolean executeKeyEvent(KeyEvent event) {
    this.mTempRect.setEmpty();
    if (canScroll()) {
        boolean handled = false;
        if (event.getAction() == 0) {
            switch (event.getKeyCode()) {
                case 19:
                    if (!event.isAltPressed()) {
                        handled = arrowScroll(33);
                        break;
                    }
                    handled = fullScroll(33);
                    break;
                case 20:
                    if (!event.isAltPressed()) {
                        handled = arrowScroll(130);
                        break;
                    }
                    handled = fullScroll(130);
                    break;
                case 62:
                    pageScroll(event.isShiftPressed() ? 33 : 130);
                    break;
            }
        }
        return handled;
    } else if (!isFocused() || event.getKeyCode() == 4) {
        return false;
    } else {
        View currentFocused = findFocus();
        if (currentFocused == this) {
            currentFocused = null;
        }
        View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, 130);
        if (nextFocused == null || nextFocused == this || !nextFocused.requestFocus(130)) {
            return false;
        }
        return true;
    }
}

public boolean arrowScroll(int direction) {
    View currentFocused = findFocus();
    if (currentFocused == this) {
        currentFocused = null;
    }
    View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, direction);
    int maxJump = getMaxScrollAmount();
    if (nextFocused == null || !isWithinDeltaOfScreen(nextFocused, maxJump, getHeight())) {
        int scrollDelta = maxJump;
        if (direction == 33 && getScrollY() < scrollDelta) {
            scrollDelta = getScrollY();
        } else if (direction == 130 && getChildCount() > 0) {
            int daBottom = getChildAt(0).getBottom();
            int screenBottom = (getScrollY() + getHeight()) - getPaddingBottom();
            if (daBottom - screenBottom < maxJump) {
                scrollDelta = daBottom - screenBottom;
            }
        }
        if (scrollDelta == 0) {
            return false;
        }
        int i;
        if (direction == 130) {
            i = scrollDelta;
        } else {
            i = -scrollDelta;
        }
        doScrollY(i);
    } else {
        nextFocused.getDrawingRect(this.mTempRect);
        offsetDescendantRectToMyCoords(nextFocused, this.mTempRect);
        doScrollY(computeScrollDeltaToGetChildRectOnScreen(this.mTempRect));
        nextFocused.requestFocus(direction);
    }
    if (currentFocused != null && currentFocused.isFocused() && isOffScreen(currentFocused)) {
        int descendantFocusability = getDescendantFocusability();
        setDescendantFocusability(131072);
        requestFocus();
        setDescendantFocusability(descendantFocusability);
    }
    return true;
}

public boolean arrowScroll(int direction)
{
    View currentFocused = findFocus();
    if (currentFocused == this)
    {
        currentFocused = null;
    }

    boolean handled = false;

    View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused,
            direction);
    if (nextFocused != null && nextFocused != currentFocused)
    {
        if (direction == View.FOCUS_LEFT)
        {
            handled = nextFocused.requestFocus();
        }
        else if (direction == View.FOCUS_RIGHT)
        {
            // If there is nothing to the right, or this is causing us to
            // jump to the left, then what we really want to do is page right.
            if (currentFocused != null && nextFocused.getLeft() <= currentFocused.getLeft())
            {
                handled = pageRight();
            }
            else
            {
                handled = nextFocused.requestFocus();
            }
        }
    }
    else if (direction == FOCUS_LEFT || direction == FOCUS_BACKWARD)
    {
        // Trying to move left and nothing there; try to page.
        handled = pageLeft();
    }
    else if (direction == FOCUS_RIGHT || direction == FOCUS_FORWARD)
    {
        // Trying to move right and nothing there; try to page.
        handled = pageRight();
    }
    if (handled)
    {
        playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction));
    }
    return handled;
}

/**
 * You can call this function yourself to have the scroll view perform
 * scrolling from a key event, just as if the event had been dispatched to
 * it by the view hierarchy.
 *
 * @param event The key event to execute.
 * @return Return true if the event was handled, else false.
 */
public boolean executeKeyEvent(KeyEvent event) {
    mTempRect.setEmpty();
    if (!canScroll()) {
        if (isFocused()) {
            View currentFocused = findFocus();
            if (currentFocused == this) currentFocused = null;
            View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, View.FOCUS_DOWN);
            return nextFocused != null && nextFocused != this && nextFocused.requestFocus(View.FOCUS_DOWN);
        }
        return false;
    }
    boolean handled = false;
    if (event.getAction() == KeyEvent.ACTION_DOWN) {
        switch (event.getKeyCode()) {
            case KeyEvent.KEYCODE_DPAD_UP:
                if (!event.isAltPressed()) {
                    handled = arrowScroll(View.FOCUS_UP, false);
                } else {
                    handled = fullScroll(View.FOCUS_UP, false);
                }
                break;
            case KeyEvent.KEYCODE_DPAD_DOWN:
                if (!event.isAltPressed()) {
                    handled = arrowScroll(View.FOCUS_DOWN, false);
                } else {
                    handled = fullScroll(View.FOCUS_DOWN, false);
                }
                break;
            case KeyEvent.KEYCODE_DPAD_LEFT:
                if (!event.isAltPressed()) {
                    handled = arrowScroll(View.FOCUS_LEFT, true);
                } else {
                    handled = fullScroll(View.FOCUS_LEFT, true);
                }
                break;
            case KeyEvent.KEYCODE_DPAD_RIGHT:
                if (!event.isAltPressed()) {
                    handled = arrowScroll(View.FOCUS_RIGHT, true);
                } else {
                    handled = fullScroll(View.FOCUS_RIGHT, true);
                }
                break;
        }
    }
    return handled;
}

public View focusSearch(View focused, int direction) {
    View result = this.mLayout.onInterceptFocusSearch(focused, direction);
    if (result != null) {
        return result;
    }
    result = FocusFinder.getInstance().findNextFocus(this, focused, direction);
    if (!(result != null || this.mAdapter == null || this.mLayout == null || isComputingLayout() || this.mLayoutFrozen)) {
        eatRequestLayout();
        result = this.mLayout.onFocusSearchFailed(focused, direction, this.mRecycler, this.mState);
        resumeRequestLayout(false);
    }
    return result != null ? result : super.focusSearch(focused, direction);
}