Java Code Examples for android.support.v7.widget.RecyclerView#getChildPosition()

@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
        RecyclerView.State state)
{
  super.getItemOffsets(outRect, view, parent, state);
  if (mDivider == null)
  {
    return;
  }
  if (parent.getChildPosition(view) < 1)
  {
    return;
  }

  if (getOrientation(parent) == LinearLayoutManager.VERTICAL)
  {
    outRect.top = mDivider.getIntrinsicHeight();
  }
  else
  {
    outRect.left = mDivider.getIntrinsicWidth();
  }
}
 

@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
                           RecyclerView.State state) {
    super.getItemOffsets(outRect, view, parent, state);
    if (mDivider == null) {
        return;
    }
    if (parent.getChildPosition(view) < 1) {
        return;
    }

    if (getOrientation(parent) == LinearLayoutManager.VERTICAL) {
        outRect.top = mDivider.getIntrinsicHeight();
    } else {
        outRect.left = mDivider.getIntrinsicWidth();
    }
}
 

@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
                           RecyclerView.State state) {
    super.getItemOffsets(outRect, view, parent, state);
    if (mDivider == null) {
        return;
    }
    if (parent.getChildPosition(view) < 1) {
        return;
    }

    if (getOrientation(parent) == LinearLayoutManager.VERTICAL) {
        outRect.top = mDivider.getIntrinsicHeight();
    } else {
        outRect.left = mDivider.getIntrinsicWidth();
    }
}
 

@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
    RecyclerView.State state) {
  super.getItemOffsets(outRect, view, parent, state);
  if (mDivider == null) {
    return;
  }
  if (parent.getChildPosition(view) < 1) {
    return;
  }

  if (getOrientation(parent) == LinearLayoutManager.VERTICAL) {
    outRect.top = mDivider.getIntrinsicHeight();
  } else {
    outRect.left = mDivider.getIntrinsicWidth();
  }
}
 

/**
 * @return Whether it is possible for the child view of this layout to
 * scroll up. Override this if the child view is a custom view.
 */
public boolean canChildScrollUp() {
    if (android.os.Build.VERSION.SDK_INT < 14) {
        if (mTarget instanceof AbsListView) {
            final AbsListView absListView = (AbsListView) mTarget;
            return absListView.getChildCount() > 0
                    && (absListView.getFirstVisiblePosition() > 0 || absListView.getChildAt(0)
                    .getTop() < absListView.getPaddingTop());
        } else {
            //Log.d(TAG, "canChildScrollUp :"+ mTarget.getScrollY()+" "+mTarget);
            boolean flag = mTarget.getScrollY() > 0;
            if (mTarget instanceof RecyclerView) {
                RecyclerView rv = (RecyclerView) mTarget;
                int firstVisiblePosition = rv.getChildPosition(rv.getChildAt(0));
                if (firstVisiblePosition == 0)
                    return rv.getChildAt(0).getTop() == 0 ? false : true;
                else
                    return true;
            }
            return flag;//ViewCompat.canScrollVertically(mTarget, -1);
        }
    } else {
        return ViewCompat.canScrollVertically(mTarget, -1);
    }
}
 

@Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
         int totalSpanCount = getSpanCount(parent);
         int itemPosition = parent.getChildPosition(view);

         boolean isLeft = isLeft(view, totalSpanCount);
         boolean isRight = isRight(view, totalSpanCount);
         boolean isFull = isFull(view, totalSpanCount);
         boolean isCenter = !isLeft && !isRight && !isFull;
         boolean isTop = isTop(parent, itemPosition, totalSpanCount);
         boolean isBottom = isBottom(parent, itemPosition, totalSpanCount);

//        LogUtil.d(itemPosition, "total:"+totalSpanCount, "index:"+getSpanIndex(view), "Size:"+getSpanSize(view), isLeft, isTop, isRight, isBottom, isFull, isCenter);

         int left = (isRight || isCenter) ? mHalfSpacingWidth : 0;
         int right = (isLeft || isCenter) ? mHalfSpacingWidth : 0;
         int top = !isTop ? mHalfSpacingHeight : 0;
         int bottom = !isBottom ? mHalfSpacingHeight : 0;

        outRect.set(left, top, right, bottom);
    }
 

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_main, container, false);
    // code copied from https://developer.android.com/training/material/lists-cards.html
    mRecyclerView = (RecyclerView) rootView.findViewById(R.id.content_recyclerview);

    mRecyclerView.setHasFixedSize(true);

    mLayoutManager = new LinearLayoutManager(getActivity());
    mRecyclerView.setLayoutManager(mLayoutManager);

    mAdapter = new MyAdapter(getActivity(), new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            int position = mRecyclerView.getChildPosition(v);
            mAdapter.toggleGroup(position);
        }
    });
    mRecyclerView.setAdapter(mAdapter);

    MyContent content = getDummyContent();
    mAdapter.add(content);
    List<MyComment> comments = getDummyComments();
    mAdapter.addAll(comments);

    if (savedInstanceState != null) {
        List<Integer> groups = savedInstanceState.getIntegerArrayList(GROUPS_KEY);
        mAdapter.restoreGroups(groups);
    }

    return rootView;
}
 

@Override
public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {


    final int childCount = parent.getChildCount();
    final RecyclerView.LayoutManager lm = parent.getLayoutManager();
    View header = headerViewHolder.itemView;
    Float lastY = null;

    for (int i = childCount - 1; i >= 0; i--) {
        final View child = parent.getChildAt(i);
        final RecyclerView.LayoutParams lp = (RecyclerView.LayoutParams)child.getLayoutParams();
        final int position = parent.getChildPosition(child);
        RecyclerView.ViewHolder holder = parent.getChildViewHolder(child);

        if (!lp.isItemRemoved()) {

            float translationY = ViewCompat.getTranslationY(child);

            if (i == 0 || isHeader(holder)) {

                float y = getHeaderY(child, lm) + translationY;

                if (lastY != null && lastY < y + headerHeight) {
                    y = lastY - headerHeight;
                }

                adapter.onBindViewHolder(headerViewHolder, position);

                c.save();
                c.translate(0, y);
                header.draw(c);
                c.restore();

                lastY = y;
            }
        }
    }
}
 

@Override
public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {


    final int childCount = parent.getChildCount();
    final RecyclerView.LayoutManager lm = parent.getLayoutManager();
    View header = headerViewHolder.itemView;
    Float lastY = null;

    for (int i = childCount - 1; i >= 0; i--) {
        final View child = parent.getChildAt(i);
        final RecyclerView.LayoutParams lp = (RecyclerView.LayoutParams)child.getLayoutParams();
        final int position = parent.getChildPosition(child);
        RecyclerView.ViewHolder holder = parent.getChildViewHolder(child);

        if (!lp.isItemRemoved()) {

            float translationY = ViewCompat.getTranslationY(child);

            if (i == 0 || isHeader(holder)) {

                float y = getHeaderY(child, lm) + translationY;

                if (lastY != null && lastY < y + headerHeight) {
                    y = lastY - headerHeight;
                }

                adapter.onBindViewHolder(headerViewHolder, position);

                c.save();
                c.translate(0, y);
                header.draw(c);
                c.restore();

                lastY = y;
            }
        }
    }
}
 

@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
    int firstVisibleItem = recyclerView.getChildPosition(recyclerView.getChildAt(0));
    int visibleItemCount = recyclerView.getChildCount();
    int totalItemCount = recyclerView.getAdapter().getItemCount();

    mHelper.onScrolled(recyclerView, firstVisibleItem, visibleItemCount, totalItemCount);

    notifyAdditionalOnScrolledListener(recyclerView, dx, dy);
}
 

/**
 * Find the new position by scanning through the items on
 * screen and finding the positional relationship.
 * This *seems* to work, another method would be to use
 * getItemOffsets, but I think that could miss items?..
 */
private int getNewPostion(RecyclerView rv)
{
    int itemsOnScreen = rv.getLayoutManager().getChildCount();

    float floatMiddleY = floatingItemBounds.top + floatingItemBounds.height()/2;

    int above=0;
    int below = Integer.MAX_VALUE;
    for (int n=0;n < itemsOnScreen;n++) //Scan though items on screen, however they may not
    {                                   // be in order!

        View view = rv.getLayoutManager().getChildAt(n);

        if (view.getVisibility() != View.VISIBLE)
            continue;

        int itemPos = rv.getChildPosition(view);

        if (itemPos == selectedDragItemPos) //Don't check against itself!
            continue;

        float viewMiddleY = view.getTop() + view.getHeight()/2;
        if (floatMiddleY > viewMiddleY) //Is above this item
        {
            if (itemPos > above)
                above = itemPos;
        }
        else if (floatMiddleY <= viewMiddleY) //Is below this item
        {
            if (itemPos < below)
                below = itemPos;
        }
    }
    debugLog("above = " + above + " below = " + below);

    if (below != Integer.MAX_VALUE) {
        if (below < selectedDragItemPos) //Need to count itself
            below++;
        return below - 1;
    }
    else
    {
        if (above < selectedDragItemPos)
            above++;

        return above;
    }
}
 

/**
 * Find the new position by scanning through the items on
 * screen and finding the positional relationship.
 * This *seems* to work, another method would be to use
 * getItemOffsets, but I think that could miss items?..
 */
private int getNewPostion(RecyclerView rv)
{
    int itemsOnScreen = rv.getLayoutManager().getChildCount();

    float floatMiddleY = floatingItemBounds.top + floatingItemBounds.height()/2;

    int above=0;
    int below = Integer.MAX_VALUE;
    for (int n=0;n < itemsOnScreen;n++) //Scan though items on screen, however they may not
    {                                   // be in order!

        View view = rv.getLayoutManager().getChildAt(n);

        if (view.getVisibility() != View.VISIBLE)
            continue;

        int itemPos = rv.getChildPosition(view);

        if (itemPos == selectedDragItemPos) //Don't check against itself!
            continue;

        float viewMiddleY = view.getTop() + view.getHeight()/2;
        if (floatMiddleY > viewMiddleY) //Is above this item
        {
            if (itemPos > above)
                above = itemPos;
        }
        else if (floatMiddleY <= viewMiddleY) //Is below this item
        {
            if (itemPos < below)
                below = itemPos;
        }
    }
    debugLog("above = " + above + " below = " + below);

    if (below != Integer.MAX_VALUE) {
        if (below < selectedDragItemPos) //Need to count itself
            below++;
        return below - 1;
    }
    else
    {
        if (above < selectedDragItemPos)
            above++;

        return above;
    }
}
 

@Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
    debugLog("onInterceptTouchEvent");

    //if (e.getAction() == MotionEvent.ACTION_DOWN)
    {
        View itemView = rv.findChildViewUnder(e.getX(), e.getY());

        if (itemView==null)
            return false;

        boolean dragging = false;

        if ((dragHandleWidth > 0 ) && (e.getX() < dragHandleWidth))
        {
            dragging = true;
        }
        else if (viewHandleId != -1)
        {
            //Find the handle in the list item
            View handleView = itemView.findViewById(viewHandleId);

            if (handleView == null)
            {
                Log.e(TAG, "The view ID " + viewHandleId + " was not found in the RecycleView item");
                return false;
            }

            //View should be visible to drag
            if(handleView.getVisibility()!=View.VISIBLE) {
                return false;
            }

            //We need to find the relative position of the handle to the parent view
            //Then we can work out if the touch is within the handle
            int[] parentItemPos = new int[2];
            itemView.getLocationInWindow(parentItemPos);

            int[] handlePos = new int[2];
            handleView.getLocationInWindow(handlePos);

            int xRel = handlePos[0] - parentItemPos[0];
            int yRel = handlePos[1] - parentItemPos[1];

            Rect touchBounds = new Rect(itemView.getLeft() + xRel, itemView.getTop() + yRel,
                    itemView.getLeft() + xRel + handleView.getWidth(),
                    itemView.getTop() + yRel  + handleView.getHeight()
            );

            if (touchBounds.contains((int)e.getX(), (int)e.getY()))
                dragging = true;

            debugLog("parentItemPos = " + parentItemPos[0] + " " + parentItemPos[1]);
            debugLog("handlePos = " + handlePos[0] + " " + handlePos[1]);
        }


        if (dragging)
        {
            debugLog("Started Drag");

            setIsDragging(true);

            floatingItem = createFloatingBitmap(itemView);

            fingerAnchorY = (int)e.getY();
            fingerOffsetInViewY = fingerAnchorY - itemView.getTop();
            fingerY = fingerAnchorY;

            selectedDragItemPos = rv.getChildPosition(itemView);
            debugLog("selectedDragItemPos = " + selectedDragItemPos);

            return true;
        }
    }
    return false;
}
 

@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView rv, RecyclerView.State state) {
    super.getItemOffsets(outRect, view, rv, state);

    debugLog("getItemOffsets");

    debugLog("View top = " + view.getTop());
    if (selectedDragItemPos != -1)
    {
        int itemPos =  rv.getChildPosition(view);
        debugLog("itemPos =" + itemPos);

        if(!canDragOver(itemPos)) {
            return;
        }

        //Movement of finger
        float totalMovement = fingerY-fingerAnchorY;

        if (itemPos == selectedDragItemPos)
        {
            view.setVisibility(View.INVISIBLE);
        }
        else
        {
            //Make view visible incase invisible
            view.setVisibility(View.VISIBLE);

            //Find middle of the floatingItem
            float floatMiddleY = floatingItemBounds.top + floatingItemBounds.height()/2;

            //Moving down the list
            //These will auto-animate if the device continually sends touch motion events
            // if (totalMovment>0)
            {
                if ((itemPos > selectedDragItemPos) && (view.getTop() < floatMiddleY))
                {
                    float amountUp = (floatMiddleY - view.getTop()) / (float)view.getHeight();
                    //  amountUp *= 0.5f;
                    if (amountUp > 1)
                        amountUp = 1;

                    outRect.top = -(int)(floatingItemBounds.height()*amountUp);
                    outRect.bottom = (int)(floatingItemBounds.height()*amountUp);
                }

            }//Moving up the list
            // else if (totalMovment < 0)
            {
                if((itemPos < selectedDragItemPos) && (view.getBottom() > floatMiddleY))
                {
                    float amountDown = ((float)view.getBottom() - floatMiddleY) / (float)view.getHeight();
                    //  amountDown *= 0.5f;
                    if (amountDown > 1)
                        amountDown = 1;

                    outRect.top = (int)(floatingItemBounds.height()*amountDown);
                    outRect.bottom = -(int)(floatingItemBounds.height()*amountDown);
                }
            }
        }
    }
    else
    {
        outRect.top = 0;
        outRect.bottom = 0;
        //Make view visible incase invisible
        view.setVisibility(View.VISIBLE);
    }
}
 

private void updatePosBasedOnReferenceList(RecyclerView referenceRv) {
    View firstVisibleView = referenceRv.getChildAt(0);
    int actual = referenceRv.getChildPosition(firstVisibleView);
    ((LinearLayoutManager) indexList.getLayoutManager()).scrollToPositionWithOffset(actual, firstVisibleView.getTop() + 0);
}
 

@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
	super.getItemOffsets(outRect, view, parent, state);

	int spacing = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, SPACING, view.getResources().getDisplayMetrics());
	int halfSpacing = spacing / 2;

	int childCount = parent.getChildCount();
	int childIndex = parent.getChildPosition(view);
	// Not an actual child (ie: during delete event)
	if(childIndex == -1) {
		return;
	}
	int spanCount = getTotalSpan(view, parent);
	int spanIndex = childIndex % spanCount;

	// If we can, use the SpanSizeLookup since headers screw up the index calculation
	RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
	if(layoutManager instanceof GridLayoutManager) {
		GridLayoutManager gridLayoutManager = (GridLayoutManager) layoutManager;
		GridLayoutManager.SpanSizeLookup spanSizeLookup = gridLayoutManager.getSpanSizeLookup();
		if(spanSizeLookup != null) {
			spanIndex = spanSizeLookup.getSpanIndex(childIndex, spanCount);
		}
	}
	int spanSize = getSpanSize(parent, childIndex);

       /* INVALID SPAN */
	if (spanCount < 1 || spanSize > 1) return;

	int margins = 0;
	if(view instanceof UpdateView) {
		View firstChild = ((ViewGroup) view).getChildAt(0);
		ViewGroup.LayoutParams layoutParams = firstChild.getLayoutParams();
		if (layoutParams instanceof LinearLayout.LayoutParams) {
			margins = ((LinearLayout.LayoutParams) layoutParams).bottomMargin;
		} else if (layoutParams instanceof FrameLayout.LayoutParams) {
			margins = ((FrameLayout.LayoutParams) layoutParams).bottomMargin;
		}
	}
	int doubleMargins = margins * 2;

	outRect.top = halfSpacing - margins;
	outRect.bottom = halfSpacing - margins;
	outRect.left = halfSpacing - margins;
	outRect.right = halfSpacing - margins;

	if (isTopEdge(childIndex, spanIndex, spanCount)) {
		outRect.top = spacing - doubleMargins;
	}

	if (isLeftEdge(spanIndex, spanCount)) {
		outRect.left = spacing - doubleMargins;
	}

	if (isRightEdge(spanIndex, spanCount)) {
		outRect.right = spacing - doubleMargins;
	}

	if (isBottomEdge(childIndex, childCount, spanCount)) {
		outRect.bottom = spacing - doubleMargins;
	}
}
 

@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView rv, RecyclerView.State state) {
    super.getItemOffsets(outRect, view, rv, state);

    debugLog("getItemOffsets");

    debugLog("View top = " + view.getTop());
    if (selectedDragItemPos != -1) {
        int itemPos = rv.getChildPosition(view);
        debugLog("itemPos =" + itemPos);

        if (!canDragOver(itemPos)) {
            return;
        }

        if (itemPos == selectedDragItemPos) {
            view.setVisibility(View.INVISIBLE);
        } else {
            //Make view visible incase invisible
            view.setVisibility(View.VISIBLE);

            //Find middle of the floatingItem
            float floatMiddleY = floatingItemBounds.top + floatingItemBounds.height() / 2;

            //Moving down the list
            //These will auto-animate if the device continually sends touch motion events
            // if (totalMovment>0)
            {
                if ((itemPos > selectedDragItemPos) && (view.getTop() < floatMiddleY)) {
                    float amountUp = (floatMiddleY - view.getTop()) / (float) view.getHeight();
                    //  amountUp *= 0.5f;
                    if (amountUp > 1)
                        amountUp = 1;

                    outRect.top = -(int) (floatingItemBounds.height() * amountUp);
                    outRect.bottom = (int) (floatingItemBounds.height() * amountUp);
                }

            }//Moving up the list
            // else if (totalMovment < 0)
            {
                if ((itemPos < selectedDragItemPos) && (view.getBottom() > floatMiddleY)) {
                    float amountDown = ((float) view.getBottom() - floatMiddleY) / (float) view.getHeight();
                    //  amountDown *= 0.5f;
                    if (amountDown > 1)
                        amountDown = 1;

                    outRect.top = (int) (floatingItemBounds.height() * amountDown);
                    outRect.bottom = -(int) (floatingItemBounds.height() * amountDown);
                }
            }
        }
    } else {
        outRect.top = 0;
        outRect.bottom = 0;
        //Make view visible incase invisible
        view.setVisibility(View.VISIBLE);
    }
}
 

/**
 * Find the new position by scanning through the items on
 * screen and finding the positional relationship.
 * This *seems* to work, another method would be to use
 * getItemOffsets, but I think that could miss items?..
 */
private int getNewPostion(RecyclerView rv) {
    int itemsOnScreen = rv.getLayoutManager().getChildCount();

    float floatMiddleY = floatingItemBounds.top + floatingItemBounds.height() / 2;

    int above = 0;
    int below = Integer.MAX_VALUE;
    for (int n = 0; n < itemsOnScreen; n++) //Scan though items on screen, however they may not
    {                                   // be in order!

        View view = rv.getLayoutManager().getChildAt(n);

        if (view.getVisibility() != View.VISIBLE)
            continue;

        int itemPos = rv.getChildPosition(view);

        if (itemPos == selectedDragItemPos) //Don't check against itself!
            continue;

        float viewMiddleY = view.getTop() + view.getHeight() / 2;
        if (floatMiddleY > viewMiddleY) //Is above this item
        {
            if (itemPos > above)
                above = itemPos;
        } else if (floatMiddleY <= viewMiddleY && itemPos < below) //Is below this item
        {
            below = itemPos;
        }
    }
    debugLog("above = " + above + " below = " + below);

    if (below != Integer.MAX_VALUE) {
        if (below < selectedDragItemPos) //Need to count itself
            below++;
        return below - 1;
    } else {
        if (above < selectedDragItemPos)
            above++;

        return above;
    }
}
 

@Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
    debugLog("onInterceptTouchEvent");

    //if (e.getAction() == MotionEvent.ACTION_DOWN)
    {
        View itemView = rv.findChildViewUnder(e.getX(), e.getY());

        if (itemView == null)
            return false;

        boolean dragging = false;

        if ((dragHandleWidth > 0) && (e.getX() < dragHandleWidth)) {
            dragging = true;
        } else if (viewHandleId != -1) {
            //Find the handle in the list item
            View handleView = itemView.findViewById(viewHandleId);

            if (handleView == null) {
                String TAG = "DragSortRecycler";
                Log.e(TAG, "The view ID " + viewHandleId + " was not found in the RecycleView item");
                return false;
            }

            //View should be visible to drag
            if (handleView.getVisibility() != View.VISIBLE) {
                return false;
            }

            //We need to find the relative position of the handle to the parent view
            //Then we can work out if the touch is within the handle
            int[] parentItemPos = new int[2];
            itemView.getLocationInWindow(parentItemPos);

            int[] handlePos = new int[2];
            handleView.getLocationInWindow(handlePos);

            int xRel = handlePos[0] - parentItemPos[0];
            int yRel = handlePos[1] - parentItemPos[1];

            Rect touchBounds = new Rect(itemView.getLeft() + xRel, itemView.getTop() + yRel,
                    itemView.getLeft() + xRel + handleView.getWidth(),
                    itemView.getTop() + yRel + handleView.getHeight()
            );

            if (touchBounds.contains((int) e.getX(), (int) e.getY()))
                dragging = true;

            debugLog("parentItemPos = " + parentItemPos[0] + " " + parentItemPos[1]);
            debugLog("handlePos = " + handlePos[0] + " " + handlePos[1]);
        }


        if (dragging) {
            debugLog("Started Drag");

            setIsDragging(true);

            floatingItem = createFloatingBitmap(itemView);

            fingerAnchorY = (int) e.getY();
            fingerOffsetInViewY = fingerAnchorY - itemView.getTop();
            fingerY = fingerAnchorY;

            selectedDragItemPos = rv.getChildPosition(itemView);
            debugLog("selectedDragItemPos = " + selectedDragItemPos);

            return true;
        }
    }
    return false;
}
 

private void updatePosBasedOnReferenceList(RecyclerView referenceRv) {
    View firstVisibleView = referenceRv.getChildAt(0);
    int actual = referenceRv.getChildPosition(firstVisibleView);
    ((LinearLayoutManager) indexList.getLayoutManager()).scrollToPositionWithOffset(actual, firstVisibleView.getTop() + 0);
}