Java Code Examples for androidx.recyclerview.widget.GridLayoutManager#getSpanCount()

/**
 * @param manager
 * @param position
 * @return
 */
protected int positionTotalSpanSize(GridLayoutManager manager, int position) {
    int totalSpanSize = 0;
    GridLayoutManager.SpanSizeLookup spanSizeLookup = manager.getSpanSizeLookup();
    int spanCount = manager.getSpanCount();
    int groupIndex = spanSizeLookup.getSpanGroupIndex(position, spanCount);
    for (int i = position; i >= 0; i--) {
        int thisGroupIndex = spanSizeLookup.getSpanGroupIndex(i, spanCount);
        if (thisGroupIndex == groupIndex) {
            totalSpanSize += spanSizeLookup.getSpanSize(i);
        } else {
            break;
        }
    }
    return totalSpanSize;
}
 

/**
 * @param manager
 * @param position
 * @return
 */
protected int positionTotalSpanSize(GridLayoutManager manager, int position) {
    int totalSpanSize = 0;
    GridLayoutManager.SpanSizeLookup spanSizeLookup = manager.getSpanSizeLookup();
    int spanCount = manager.getSpanCount();
    int groupIndex = spanSizeLookup.getSpanGroupIndex(position, spanCount);
    for (int i = position; i >= 0; i--) {
        int thisGroupIndex = spanSizeLookup.getSpanGroupIndex(i, spanCount);
        if (thisGroupIndex == groupIndex) {
            totalSpanSize += spanSizeLookup.getSpanSize(i);
        } else {
            break;
        }
    }
    return totalSpanSize;
}
 

GridLayoutManager.SpanSizeLookup getSpanSizeLookup(final GridLayoutManager gridLayoutManager) {
    return new GridLayoutManager.SpanSizeLookup() {
        @Override
        public int getSpanSize(int position) {
            SectionAdapter adapter = getCurrentAdapter();
            if (adapter != null) {
                int viewType = adapter.getItemViewType(position);
                if (viewType == SectionAdapter.VIEW_TYPE_HEADER) {
                    return gridLayoutManager.getSpanCount();
                } else {
                    return 1;
                }
            } else {
                return 1;
            }
        }
    };
}
 

private int getItemCount() {
    LinearLayoutManager linearLayoutManager = getVerticalLinearLayoutManager();
    if (linearLayoutManager == null) {
        return 0;
    }
    int itemCount = linearLayoutManager.getItemCount();
    if (itemCount == 0) {
        return 0;
    }
    if (linearLayoutManager instanceof GridLayoutManager) {
        GridLayoutManager gridLayoutManager = (GridLayoutManager) linearLayoutManager;
        itemCount = (itemCount - 1) / gridLayoutManager.getSpanCount() + 1;
    }
    return itemCount;
}
 

@Override
public GridLayoutManager.SpanSizeLookup getSpanSizeLookup(final GridLayoutManager gridLayoutManager) {
    return new GridLayoutManager.SpanSizeLookup() {
        @Override
        public int getSpanSize(int position) {
            int viewType = entryGridAdapter.getItemViewType(position);
            if (viewType == EntryGridAdapter.VIEW_TYPE_SONG || viewType == EntryGridAdapter.VIEW_TYPE_HEADER || viewType == EntryInfiniteGridAdapter.VIEW_TYPE_LOADING) {
                return gridLayoutManager.getSpanCount();
            } else {
                return 1;
            }
        }
    };
}
 

@Override
public void onScrolled(int dx, int dy) {
    super.onScrolled(dx, dy);
    if (onRecyclerViewPreloadListener != null) {
        if (isEnabledLoadMore) {
            LayoutManager layoutManager = getLayoutManager();
            if (layoutManager == null) {
                throw new RuntimeException("LayoutManager is null,Please check it!");
            }
            Adapter adapter = getAdapter();
            if (adapter == null) {
                throw new RuntimeException("Adapter is null,Please check it!");
            }
            boolean isReachBottom = false;
            if (layoutManager instanceof GridLayoutManager) {
                GridLayoutManager gridLayoutManager = (GridLayoutManager) layoutManager;
                int rowCount = adapter.getItemCount() / gridLayoutManager.getSpanCount();
                int lastVisibleRowPosition = gridLayoutManager.findLastVisibleItemPosition() / gridLayoutManager.getSpanCount();
                isReachBottom = (lastVisibleRowPosition >= rowCount - reachBottomRow);
            }

            if (!isReachBottom) {
                isInTheBottom = false;
            } else if (!isInTheBottom) {
                onRecyclerViewPreloadListener.onRecyclerViewPreloadMore();
                if (dy > 0) {
                    isInTheBottom = true;
                }
            } else {
                // 属于首次进入屏幕未滑动且内容未超过一屏，用于确保分页数设置过小导致内容不足二次上拉加载...
                if (dy == 0) {
                    isInTheBottom = false;
                }
            }
        }
    }
}
 

@Override
public void onAttach(Activity activity) {
    super.onAttach(activity);

    adapter.setThermometerMode();
    adapter.setBlueGeckoTabSelected(true);

    discovery.connect(activity);

    layout = new GridLayoutManager(activity, activity.getResources().getInteger(R.integer.device_selection_columns), LinearLayoutManager.VERTICAL, false);
    itemDecoration = new RecyclerView.ItemDecoration() {
        final int horizontalMargin = getResources().getDimensionPixelSize(R.dimen.item_margin);

        @Override
        public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
            final int columns = layout.getSpanCount();
            if (columns == 1) {
                outRect.set(0, 0, 0, 0);
            } else {
                int itemPos = parent.getChildAdapterPosition(view);
                if (itemPos % columns == columns - 1) {
                    outRect.set(0, 0, 0, 0);
                } else {
                    outRect.set(0, 0, horizontalMargin, 0);
                }
            }
        }
    };
}
 

private int getSpanCount() {
    if (spanCount != 0) {
        return spanCount;
    }
    GridLayoutManager gridLayoutManager = (GridLayoutManager) recyclerView.getLayoutManager();
    if (gridLayoutManager != null) {
        spanCount = gridLayoutManager.getSpanCount();
        return spanCount;
    }
    return 0;
}
 

private int getGroupIndex(int position, RecyclerView parent) {
    if (parent.getLayoutManager() instanceof GridLayoutManager) {
        GridLayoutManager layoutManager = (GridLayoutManager) parent.getLayoutManager();
        GridLayoutManager.SpanSizeLookup spanSizeLookup = layoutManager.getSpanSizeLookup();
        int spanCount = layoutManager.getSpanCount();
        return spanSizeLookup.getSpanGroupIndex(position, spanCount);
    }

    return position;
}
 

public void checkForNewElements(RecyclerView recyclerView) {
    int currentOffset = mLazyFetchingActivity.getCurrentOffset();
    int maxElementsToFetchTotal = mLazyFetchingActivity.getMaxElementsToFetch();

    // If the task has already been run, make a new task as a task can only be run once.
    if (getElementsTask.getStatus() == AsyncTask.Status.FINISHED) {
        getElementsTask = new GetVisualElementsTask<>(mLazyFetchingActivity);
    }

    // Only bother to check if we need to fetch more game objects if we are not already in the process of doing so.
    if (getElementsTask.getStatus() != AsyncTask.Status.RUNNING && currentOffset < maxElementsToFetchTotal) {
        GridLayoutManager lm = (GridLayoutManager) recyclerView.getLayoutManager();
        RecyclerView.Adapter mAdapter = recyclerView.getAdapter();
        if (mAdapter == null) {
            return;
        }

        int lastViewPosition = lm.findLastVisibleItemPosition();
        int spanCount = lm.getSpanCount();
        int itemCount = mAdapter.getItemCount();
        final double FETCH_WHEN_BELOW_FIVE = 5;
        final double NUMBER_OF_ROWS = Math.ceil(itemCount / (spanCount * 1.0)); // Round UP to the nearest Integer
        final double LAST_ROW_VISIBLE = Math.ceil(lastViewPosition / (spanCount * 1.0)); // Round UP to the nearest Integer

        // If the Second to last or the last row is visible, then fetch more game objects.
        if (LAST_ROW_VISIBLE >= NUMBER_OF_ROWS - FETCH_WHEN_BELOW_FIVE) {
            getElementsTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
            mLazyFetchingActivity.startProgress();
        }
    }
}
 

@Override
public GridLayoutManager.SpanSizeLookup getSpanSizeLookup(final GridLayoutManager gridLayoutManager) {
    return new GridLayoutManager.SpanSizeLookup() {
        @Override
        public int getSpanSize(int position) {
            int viewType = adapter.getItemViewType(position);
            if (viewType == EntryGridAdapter.VIEW_TYPE_SONG || viewType == EntryGridAdapter.VIEW_TYPE_HEADER || viewType == ArtistAdapter.VIEW_TYPE_ARTIST) {
                return gridLayoutManager.getSpanCount();
            } else {
                return 1;
            }
        }
    };
}
 

private int getFirstItemPosition() {
    int position = getFirstItemAdapterPosition();
    LinearLayoutManager linearLayoutManager = getVerticalLinearLayoutManager();
    if (linearLayoutManager == null) {
        return RecyclerView.NO_POSITION;
    }
    if (linearLayoutManager instanceof GridLayoutManager) {
        GridLayoutManager gridLayoutManager = (GridLayoutManager) linearLayoutManager;
        position /= gridLayoutManager.getSpanCount();
    }
    return position;
}
 

@Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
    super.onAttachedToRecyclerView(recyclerView);
    RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();

    if (layoutManager instanceof GridLayoutManager) {
        GridLayoutManager gridLayoutManager = ((GridLayoutManager) layoutManager);
        if (mGridSpanSizeLookup == null) {
            mSpanCount = gridLayoutManager.getSpanCount();
            mGridSpanSizeLookup = getGridSpanSizeLookup();
        }
        gridLayoutManager.setSpanSizeLookup(mGridSpanSizeLookup);
    }
}
 

public EndlessRecyclerViewScrollListener(GridLayoutManager layoutManager) {
    this.mLayoutManager = layoutManager;
    visibleThreshold = visibleThreshold * layoutManager.getSpanCount();
}
 

public EndlessRecyclerViewScrollListener(GridLayoutManager layoutManager) {
    this.mLayoutManager = layoutManager;
    visibleThreshold = visibleThreshold * layoutManager.getSpanCount();
}
 

public EndlessUpScrollListener(GridLayoutManager layoutManager) {
    this.mLayoutManager = layoutManager;
    visibleThreshold = visibleThreshold * layoutManager.getSpanCount();
}
 

/***/
private void drawGrideview1(Canvas canvas, RecyclerView parent) {
    GridLayoutManager linearLayoutManager = (GridLayoutManager) parent.getLayoutManager();
    int childSize = parent.getChildCount();
    int top, bottom, left, right, spancount;
    spancount = linearLayoutManager.getSpanCount();
    for (int i = 0; i < childSize; i++) {
        final View child = parent.getChildAt(i);
        //画横线
        RecyclerView.LayoutParams layoutParams = (RecyclerView.LayoutParams) child.getLayoutParams();
        top = child.getBottom() + layoutParams.bottomMargin;
        bottom = top + space;
        left = layoutParams.leftMargin + child.getPaddingLeft() + space;
        right = child.getMeasuredWidth() * (i + 1) + left + space * i;
        if (mDivider != null) {
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(canvas);
        }
        if (mPaint != null) {
            canvas.drawRect(left, top, right, bottom, mPaint);
        }
        //画竖线
        top = (layoutParams.topMargin + space) * (i / linearLayoutManager.getSpanCount() + 1);
        bottom = (child.getMeasuredHeight() + space) * (i / linearLayoutManager.getSpanCount() + 1) + space;
        left = child.getRight() + layoutParams.rightMargin;
        right = left + space;
        if (mDivider != null) {
            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(canvas);
        }
        if (mPaint != null) {
            canvas.drawRect(left, top, right, bottom, mPaint);
        }

        //画上缺失的线框
        if (i < spancount) {
            top = child.getTop() + layoutParams.topMargin;
            bottom = top + space;
            left = (layoutParams.leftMargin + space) * (i + 1);
            right = child.getMeasuredWidth() * (i + 1) + left + space * i;
            if (mDivider != null) {
                mDivider.setBounds(left, top, right, bottom);
                mDivider.draw(canvas);
            }
            if (mPaint != null) {
                canvas.drawRect(left, top, right, bottom, mPaint);
            }
        }
        if (i % spancount == 0) {
            top = (layoutParams.topMargin + space) * (i / linearLayoutManager.getSpanCount() + 1);
            bottom = (child.getMeasuredHeight() + space) * (i / linearLayoutManager.getSpanCount() + 1) + space;
            left = child.getLeft() + layoutParams.leftMargin;
            right = left + space;
            if (mDivider != null) {
                mDivider.setBounds(left, top, right, bottom);
                mDivider.draw(canvas);
            }
            if (mPaint != null) {
                canvas.drawRect(left, top, right, bottom, mPaint);
            }
        }
    }
}
 

@NonNull
private ItemDecoration createItemDecoration() {
  return new ItemDecoration() {

    private final Calendar startItem = UtcDates.getUtcCalendar();
    private final Calendar endItem = UtcDates.getUtcCalendar();

    @Override
    public void onDraw(
        @NonNull Canvas canvas, @NonNull RecyclerView recyclerView, @NonNull State state) {
      if (!(recyclerView.getAdapter() instanceof YearGridAdapter)
          || !(recyclerView.getLayoutManager() instanceof GridLayoutManager)) {
        return;
      }
      YearGridAdapter adapter = (YearGridAdapter) recyclerView.getAdapter();
      GridLayoutManager layoutManager = (GridLayoutManager) recyclerView.getLayoutManager();

      for (Pair<Long, Long> range : dateSelector.getSelectedRanges()) {
        if (range.first == null || range.second == null) {
          continue;
        }
        startItem.setTimeInMillis(range.first);
        endItem.setTimeInMillis(range.second);

        int firstHighlightPosition = adapter.getPositionForYear(startItem.get(Calendar.YEAR));
        int lastHighlightPosition = adapter.getPositionForYear(endItem.get(Calendar.YEAR));
        View firstView = layoutManager.findViewByPosition(firstHighlightPosition);
        View lastView = layoutManager.findViewByPosition(lastHighlightPosition);

        int firstRow = firstHighlightPosition / layoutManager.getSpanCount();
        int lastRow = lastHighlightPosition / layoutManager.getSpanCount();

        for (int row = firstRow; row <= lastRow; row++) {
          int firstPositionInRow = row * layoutManager.getSpanCount();
          View viewInRow = layoutManager.findViewByPosition(firstPositionInRow);
          if (viewInRow == null) {
            continue;
          }
          int top = viewInRow.getTop() + calendarStyle.year.getTopInset();
          int bottom = viewInRow.getBottom() - calendarStyle.year.getBottomInset();
          int left = row == firstRow ? firstView.getLeft() + firstView.getWidth() / 2 : 0;
          int right =
              row == lastRow
                  ? lastView.getLeft() + lastView.getWidth() / 2
                  : recyclerView.getWidth();
          canvas.drawRect(left, top, right, bottom, calendarStyle.rangeFill);
        }
      }
    }
  };
}
 

@Override
public void onAttach(Context context) {
    super.onAttach(context);

    adapter = new ScannedDevicesAdapter(new DeviceInfoViewHolder.Generator(R.layout.device_item) {
        @Override
        public DeviceInfoViewHolder generate(View itemView) {
            final ViewHolder holder = new ViewHolder(itemView);
            holder.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    int adapterPos = holder.getAdapterPosition();
                    if (adapterPos != RecyclerView.NO_POSITION) {
                        BluetoothDeviceInfo devInfo = (BluetoothDeviceInfo) adapter.getDevicesInfo().get(adapterPos);
                        connect(devInfo);
                    }
                }
            });
            return holder;
        }

    }, context);

    discovery = new Discovery(adapter, this);

    adapter.setThermometerMode();

    discovery.connect(context);

    layout = new GridLayoutManager(context, context.getResources().getInteger(R.integer.device_selection_columns), LinearLayoutManager.VERTICAL, false);
    itemDecoration = new RecyclerView.ItemDecoration() {
        final int horizontalMargin = getResources().getDimensionPixelSize(R.dimen.item_margin);

        @Override
        public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
            final int columns = layout.getSpanCount();
            if (columns == 1) {
                outRect.set(0, 0, 0, 0);
            } else {
                int itemPos = parent.getChildAdapterPosition(view);
                if (itemPos % columns == columns - 1) {
                    outRect.set(0, 0, 0, 0);
                } else {
                    outRect.set(0, 0, horizontalMargin, 0);
                }
            }
        }
    };
}
 

public int getSpanCount() {
    GridLayoutManager layoutManager = gridLayoutManager.get();
    return layoutManager == null ? 1 : layoutManager.getSpanCount();
}