androidx.recyclerview.widget.RecyclerView#HORIZONTAL源码实例Demo

public static boolean isScrollingView(View view) {
    if (ViewCatcherUtil.isViewPager(view)
            || view instanceof HorizontalScrollView
            || view instanceof WebView) {
        return true;
    } else if (ViewCatcherUtil.isRecyclerView(view)) {
        RecyclerView recyclerView = (RecyclerView) view;
        RecyclerView.LayoutManager manager = recyclerView.getLayoutManager();
        if (manager != null) {
            if (manager instanceof LinearLayoutManager) {
                LinearLayoutManager linearManager = ((LinearLayoutManager) manager);
                return linearManager.getOrientation() == RecyclerView.HORIZONTAL;
            } else if (manager instanceof StaggeredGridLayoutManager) {
                StaggeredGridLayoutManager gridLayoutManager =
                        (StaggeredGridLayoutManager) manager;
                return gridLayoutManager.getOrientation() == RecyclerView.HORIZONTAL;
            }
        }
    }
    return false;
}
 

public SimilarAppcAppsViewHolder(View view, DecimalFormat oneDecimalFormat,
    PublishSubject<SimilarAppClickEvent> similarAppClick) {
  super(view);
  this.oneDecimalFormat = oneDecimalFormat;
  this.similarAppClick = similarAppClick;

  similarAppcApps = view.findViewById(R.id.similar_appc_list);
  similarAppcApps.setNestedScrollingEnabled(false);
  HorizontalHeaderItemDecoration similarAppcHeaderItemDecoration =
      new HorizontalHeaderItemDecoration(view.getContext(), similarAppcApps,
          R.layout.appview_appc_similar_header,
          AptoideUtils.ScreenU.getPixelsForDip(112, view.getResources()),
          AptoideUtils.ScreenU.getPixelsForDip(5, view.getResources()));
  similarAppcApps.addItemDecoration(similarAppcHeaderItemDecoration);

  LinearLayoutManager similarAppcLayout =
      new LinearLayoutManager(view.getContext(), RecyclerView.HORIZONTAL, false);

  similarAppcApps.setLayoutManager(similarAppcLayout);
  SnapHelper similarSnap = new SnapToStartHelper();
  similarSnap.attachToRecyclerView(similarAppcApps);

  similarAppcApps.setAdapter(getSimilarAdapter());
}
 

private void initialize(@NonNull Context context) {
    inflate(context, R.layout.mapwize_mode_view, this);
    recyclerView = findViewById(R.id.mapwize_mode_recycler_view);
    LinearLayoutManager lm = new LinearLayoutManager(context, RecyclerView.HORIZONTAL, false);

    recyclerView.setLayoutManager(lm);
    modeViewAdapter = new ModeViewAdapter();
    modeViewAdapter.setListener(this);
    recyclerView.setAdapter(modeViewAdapter);
}
 

public static boolean canAutoLoadMore(View view) {
    if (ViewCatcherUtil.isRecyclerView(view)) {
        RecyclerView recyclerView = (RecyclerView) view;
        RecyclerView.LayoutManager manager = recyclerView.getLayoutManager();
        if (manager == null) {
            return false;
        }
        int lastVisiblePosition = 0;
        if (manager instanceof LinearLayoutManager) {
            LinearLayoutManager linearManager = ((LinearLayoutManager) manager);
            if (linearManager.getOrientation() != RecyclerView.HORIZONTAL) {
                return false;
            }
            lastVisiblePosition = linearManager.findLastVisibleItemPosition();
        } else if (manager instanceof StaggeredGridLayoutManager) {
            StaggeredGridLayoutManager gridLayoutManager = (StaggeredGridLayoutManager) manager;
            if (gridLayoutManager.getOrientation() != RecyclerView.HORIZONTAL) {
                return false;
            }
            int[] lastPositions = new int[gridLayoutManager.getSpanCount()];
            gridLayoutManager.findLastVisibleItemPositions(lastPositions);
            for (int value : lastPositions) {
                if (value > lastVisiblePosition) {
                    lastVisiblePosition = value;
                }
            }
        }
        RecyclerView.Adapter adapter = recyclerView.getAdapter();
        return adapter != null
                && adapter.getItemCount() > 0
                && lastVisiblePosition >= 0
                && lastVisiblePosition >= adapter.getItemCount() - 1;
    }
    return false;
}
 

public static boolean canAutoRefresh(View view) {
    if (ViewCatcherUtil.isRecyclerView(view)) {
        RecyclerView recyclerView = (RecyclerView) view;
        RecyclerView.LayoutManager manager = recyclerView.getLayoutManager();
        if (manager == null) {
            return false;
        }
        int firstVisiblePosition = -1;
        if (manager instanceof LinearLayoutManager) {
            LinearLayoutManager linearManager = ((LinearLayoutManager) manager);
            if (linearManager.getOrientation() != RecyclerView.HORIZONTAL) {
                return false;
            }
            firstVisiblePosition = linearManager.findFirstVisibleItemPosition();
        } else if (manager instanceof StaggeredGridLayoutManager) {
            StaggeredGridLayoutManager gridLayoutManager = (StaggeredGridLayoutManager) manager;
            if (gridLayoutManager.getOrientation() != RecyclerView.HORIZONTAL) {
                return false;
            }
            int[] firstPositions = new int[gridLayoutManager.getSpanCount()];
            gridLayoutManager.findFirstVisibleItemPositions(firstPositions);
            for (int value : firstPositions) {
                if (value == 0) {
                    firstVisiblePosition = 0;
                    break;
                }
            }
        }
        RecyclerView.Adapter adapter = recyclerView.getAdapter();
        return adapter != null && firstVisiblePosition == 0;
    }
    return false;
}
 

public void setOrientation(int orientation) {
    switch (orientation) {
        case RecyclerView.HORIZONTAL:
            mOrientationHelper = new HorizontalHelper();
            break;
        case RecyclerView.VERTICAL:
            mOrientationHelper = new VerticalHelper();
            break;
        default:
            throw new IllegalArgumentException("Unknown orientation " + orientation);
    }
    mOrientation = orientation;
    removeAllViews();
    requestLayout();
}
 

@Override
public int computeHorizontalScrollExtent(RecyclerView.State state) {
    if (getOrientation() == RecyclerView.HORIZONTAL) {
        return super.computeHorizontalScrollExtent(state);
    }
    return computeHorizontalScrollExtent();
}
 

/**
 * 计算水平滚动边界
 *
 * @return 滚动边界
 */
protected int computeHorizontalScrollExtent() {
    if (getOrientation() == RecyclerView.HORIZONTAL) {
        final RecyclerView view = getRecyclerView();
        return view == null ? 0 : view.computeHorizontalScrollExtent();
    }
    return getMeasuredWidth() - getPaddingLeft() - getPaddingRight();
}
 

/**
 * 计算水平滚动范围
 *
 * @return 滚动范围
 */
protected int computeHorizontalScrollRange() {
    if (getOrientation() == RecyclerView.HORIZONTAL) {
        final RecyclerView view = getRecyclerView();
        return view == null ? 0 : view.computeHorizontalScrollRange();
    }
    return getChildMaxWidth(mChildMaxWidth) + mLeftDecorationMaxWidthOfChildMaxWidth +
            mRightDecorationMaxWidthOfChildMaxWidth;
}
 

/**
 * 判断另一方向是否能够滚动
 *
 * @return 是否能够
 */
public boolean canScrollAnotherDirection() {
    if (getOrientation() == RecyclerView.HORIZONTAL) {
        return canScrollVertically();
    } else {
        return canScrollHorizontally();
    }
}
 

@Override
public int scrollHorizontallyBy(int dx, RecyclerView.Recycler recycler,
                                RecyclerView.State state) {
    if (getOrientation() == RecyclerView.HORIZONTAL) {
        return super.scrollHorizontallyBy(dx, recycler, state);
    }
    return scrollBy(dx);
}
 

@Override
public void layoutDecoratedWithMargins(@NonNull View child, int left, int top, int right, int bottom) {
    if (!mCenter) {
        super.layoutDecoratedWithMargins(child, left, top, right, bottom);
        return;
    }
    final RecyclerView.LayoutParams lp = (RecyclerView.LayoutParams) child.getLayoutParams();
    final int leftDecorationWidth = getLeftDecorationWidth(child);
    final int topDecorationHeight = getTopDecorationHeight(child);
    final int rightDecorationWidth = getRightDecorationWidth(child);
    final int bottomDecorationHeight = getBottomDecorationHeight(child);
    final ViewGroup parent = (ViewGroup) child.getParent();
    final int offset;
    if (getOrientation() == RecyclerView.HORIZONTAL) {
        final int contentHeight = parent.getMeasuredHeight() -
                parent.getPaddingTop() - parent.getPaddingBottom();
        offset = (contentHeight - (bottom - top)) / 2;
        child.layout(left + leftDecorationWidth + lp.leftMargin,
                top + topDecorationHeight + lp.topMargin + offset,
                right - rightDecorationWidth - lp.rightMargin,
                bottom - bottomDecorationHeight - lp.bottomMargin + offset);
    } else {
        final int contentWidth = parent.getMeasuredWidth() -
                parent.getPaddingLeft() - parent.getPaddingRight();
        offset = (contentWidth - (right - left)) / 2;
        child.layout(left + leftDecorationWidth + offset + lp.leftMargin,
                top + topDecorationHeight + lp.topMargin,
                right - rightDecorationWidth - lp.rightMargin + offset,
                bottom - bottomDecorationHeight - lp.bottomMargin);
    }
}
 

public void init(Context context, DatePickerDialog.ScrollOrientation scrollOrientation) {
    @RecyclerView.Orientation
    int layoutOrientation = scrollOrientation == DatePickerDialog.ScrollOrientation.VERTICAL
            ? RecyclerView.VERTICAL
            : RecyclerView.HORIZONTAL;
    LinearLayoutManager linearLayoutManager = new LinearLayoutManager(context, layoutOrientation, false);
    setLayoutManager(linearLayoutManager);
    setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
    setVerticalScrollBarEnabled(false);
    setHorizontalScrollBarEnabled(false);
    setClipChildren(false);

    mContext = context;
    setUpRecyclerView(scrollOrientation);
}
 

public TrendHorizontalLinearLayoutManager(Context context, int fillCount) {
    super(context, RecyclerView.HORIZONTAL, false);
    this.context = context;
    this.fillCount = fillCount;
}