android.support.v7.widget.RecyclerView#findViewHolderForLayoutPosition

Source File: CommonUtils.java From WanAndroid with MIT License

5 votes

/**
     * 设置Navigation menu item 高度
     */
    private void resetItemLayout(NavigationView navigationView) {
        //通过反射拿到menu的item布局。修改布局参数
        try {
            Field mPresenter = NavigationView.class.getDeclaredField("mPresenter");
            mPresenter.setAccessible(true);
            //此处mPresenter.get(navigationView)会得到一个NavigationMenuPresenter对象，但是该类是@hide的。所以此处直接再拿其内部的NavigationMenuView。该类也是@hide的。需要注意的是，该类继承自RecyclerView。菜单的布局也就是由其完成的。
            Field mMenuView = mPresenter.get(navigationView).getClass().getDeclaredField("mMenuView");
            mMenuView.setAccessible(true);
            //由于NavigationMenuView是隐藏类。此处用其父类。
            RecyclerView recycler = (RecyclerView) mMenuView.get(mPresenter.get(navigationView));
            for (int i = 0; i < recycler.getAdapter().getItemCount(); i++) {
                RecyclerView.ViewHolder holder = recycler.findViewHolderForLayoutPosition(i);
                //这里看实际项目了。我的项目中添加了一个head。
//                if (i == 0 || holder == null)//因为这里有一个header。所以要先排除第一个
//                    continue;
                if (holder == null)
                    return;
                //剩下的就是修改整体布局参数了。
                ViewGroup.LayoutParams params = holder.itemView.getLayoutParams();
                params.width = ViewGroup.LayoutParams.MATCH_PARENT;
                params.height = 10;
                holder.itemView.setLayoutParams(params);
            }
        } catch (NoSuchFieldException | IllegalAccessException e) {
            e.printStackTrace();
        }
    }

Source File: BaseQuickAdapter.java From imsdk-android with MIT License

5 votes

@Nullable
public View getViewByPosition(RecyclerView recyclerView, int position, @IdRes int viewId) {
    if (recyclerView == null) {
        return null;
    }
    BaseViewHolder viewHolder = (BaseViewHolder) recyclerView.findViewHolderForLayoutPosition(position);
    if (viewHolder == null) {
        return null;
    }
    return viewHolder.getView(viewId);
}

Source File: BaseQuickAdapter.java From demo4Fish with MIT License

5 votes

public View getViewByPosition(RecyclerView recyclerView, int position, int viewId) {
    if (recyclerView == null) {
        return null;
    }
    BaseViewHolder viewHolder = (BaseViewHolder) recyclerView.findViewHolderForLayoutPosition(position);
    return viewHolder.getView(viewId);
}

Source File: BaseQuickAdapter.java From JD-Test with Apache License 2.0

5 votes

public View getViewByPosition(RecyclerView recyclerView, int position, int viewId) {
    if (recyclerView == null) {
        return null;
    }
    BaseViewHolder viewHolder = (BaseViewHolder) recyclerView.findViewHolderForLayoutPosition(position);
    return viewHolder.getView(viewId);
}

Source File: RecyclerItemViewAssertion.java From mangosta-android with Apache License 2.0

5 votes

@Override
public final void check(View view, NoMatchingViewException e) {
    RecyclerView recyclerView = (RecyclerView) view;
    RecyclerView.ViewHolder viewHolderForPosition = recyclerView.findViewHolderForLayoutPosition(position);
    if (viewHolderForPosition == null) {
        throw (new PerformException.Builder())
                .withActionDescription(toString())
                .withViewDescription(HumanReadables.describe(view))
                .withCause(new IllegalStateException("No view holder at position: " + position))
                .build();
    } else {
        View viewAtPosition = viewHolderForPosition.itemView;
        itemViewAssertion.check(item, viewAtPosition, e);
    }
}

Source File: RecyclerItemViewAssertion.java From KataSuperHeroesAndroid with Apache License 2.0

5 votes

@Override public final void check(View view, NoMatchingViewException e) {
  RecyclerView recyclerView = (RecyclerView) view;
  RecyclerView.ViewHolder viewHolderForPosition =
      recyclerView.findViewHolderForLayoutPosition(position);
  if (viewHolderForPosition == null) {
    throw (new PerformException.Builder()).withActionDescription(toString())
        .withViewDescription(HumanReadables.describe(view))
        .withCause(new IllegalStateException("No view holder at position: " + position))
        .build();
  } else {
    View viewAtPosition = viewHolderForPosition.itemView;
    itemViewAssertion.check(item, viewAtPosition, e);
  }
}

Source File: RecyclerItemViewAssertion.java From Game-of-Thrones with Apache License 2.0

5 votes

@Override
public final void check(View view, NoMatchingViewException e) {
  RecyclerView recyclerView = (RecyclerView) view;
  RecyclerView.ViewHolder viewHolderForPosition =
      recyclerView.findViewHolderForLayoutPosition(position);
  if (viewHolderForPosition == null) {
    throw (new PerformException.Builder()).withActionDescription(toString())
        .withViewDescription(HumanReadables.describe(view))
        .withCause(new IllegalStateException("No view holder at position: " + position))
        .build();
  } else {
    View viewAtPosition = viewHolderForPosition.itemView;
    itemViewAssertion.check(item, viewAtPosition, e);
  }
}

Source File: SuspensionDecoration.java From Focus with GNU General Public License v3.0

4 votes

@Override
public void onDrawOver(Canvas c, final RecyclerView parent, RecyclerView.State state) {//最后调用 绘制在最上层
    int pos = ((LinearLayoutManager) (parent.getLayoutManager())).findFirstVisibleItemPosition();
    pos -= getHeaderViewCount();
    //pos为1，size为1，1>0? true
    if (mDatas == null || mDatas.isEmpty() || pos > mDatas.size() - 1 || pos < 0 || !mDatas.get(pos).isShowSuspension()) {
        return;//越界
    }

    String tag = mDatas.get(pos).getSuspensionTag();
    //View child = parent.getChildAt(pos);
    View child = parent.findViewHolderForLayoutPosition(pos + getHeaderViewCount()).itemView;//出现一个奇怪的bug，有时候child为空，所以将 child = parent.getChildAt(i)。-》 parent.findViewHolderForLayoutPosition(pos).itemView

    boolean flag = false;//定义一个flag，Canvas是否位移过的标志
    if ((pos + 1) < mDatas.size()) {//防止数组越界（一般情况不会出现）
        if (null != tag && !tag.equals(mDatas.get(pos + 1).getSuspensionTag())) {//当前第一个可见的Item的tag，不等于其后一个item的tag，说明悬浮的View要切换了
            Log.d("zxt", "onDrawOver() called with: c = [" + child.getTop());//当getTop开始变负，它的绝对值，是第一个可见的Item移出屏幕的距离，
            if (child.getHeight() + child.getTop() < mTitleHeight) {//当第一个可见的item在屏幕中还剩的高度小于title区域的高度时，我们也该开始做悬浮Title的“交换动画”
                c.save();//每次绘制前 保存当前Canvas状态，
                flag = true;

                //一种头部折叠起来的视效，个人觉得也还不错~
                //可与123行 c.drawRect 比较，只有bottom参数不一样，由于 child.getHeight() + child.getTop() < mTitleHeight，所以绘制区域是在不断的减小，有种折叠起来的感觉
             /*   c.clipRect(parent.getPaddingLeft(), parent.getPaddingTop(), parent.getRight() - parent.getPaddingRight(), parent.getPaddingTop() + child.getHeight() + child.getTop());*/

                //类似饿了么点餐时,商品列表的悬停头部切换“动画效果”
                //上滑时，将canvas上移 （y为负数） ,所以后面canvas 画出来的Rect和Text都上移了，有种切换的“动画”感觉
                c.translate(0, child.getHeight() + child.getTop() - mTitleHeight);
            }
        }
    }
    mPaint.setColor(COLOR_TITLE_BG);
    c.drawRect(parent.getPaddingLeft(), parent.getPaddingTop(), parent.getRight() - parent.getPaddingRight(), parent.getPaddingTop() + mTitleHeight, mPaint);
    mPaint.setColor(COLOR_TITLE_FONT);
    mPaint.getTextBounds(tag, 0, tag.length(), mBounds);
    c.drawText(tag, child.getPaddingLeft() + 30,
            parent.getPaddingTop() + mTitleHeight - (mTitleHeight / 2 - mBounds.height() / 2),
            mPaint);//滚动的过程中绘制title
    if (flag)
        c.restore();//恢复画布到之前保存的状态

}

Source File: SuspensionDecoration.java From Focus with GNU General Public License v3.0

4 votes

@Override
public void onDrawOver(Canvas c, final RecyclerView parent, RecyclerView.State state) {//最后调用 绘制在最上层
    int pos = ((LinearLayoutManager) (parent.getLayoutManager())).findFirstVisibleItemPosition();
    pos -= getHeaderViewCount();
    //pos为1，size为1，1>0? true
    if (mDatas == null || mDatas.isEmpty() || pos > mDatas.size() - 1 || pos < 0 || !mDatas.get(pos).isShowSuspension()) {
        return;//越界
    }

    String tag = mDatas.get(pos).getSuspensionTag();
    //View child = parent.getChildAt(pos);
    View child = parent.findViewHolderForLayoutPosition(pos + getHeaderViewCount()).itemView;//出现一个奇怪的bug，有时候child为空，所以将 child = parent.getChildAt(i)。-》 parent.findViewHolderForLayoutPosition(pos).itemView

    boolean flag = false;//定义一个flag，Canvas是否位移过的标志
    if ((pos + 1) < mDatas.size()) {//防止数组越界（一般情况不会出现）
        if (null != tag && !tag.equals(mDatas.get(pos + 1).getSuspensionTag())) {//当前第一个可见的Item的tag，不等于其后一个item的tag，说明悬浮的View要切换了
            Log.d("zxt", "onDrawOver() called with: c = [" + child.getTop());//当getTop开始变负，它的绝对值，是第一个可见的Item移出屏幕的距离，
            if (child.getHeight() + child.getTop() < mTitleHeight) {//当第一个可见的item在屏幕中还剩的高度小于title区域的高度时，我们也该开始做悬浮Title的“交换动画”
                c.save();//每次绘制前 保存当前Canvas状态，
                flag = true;

                //一种头部折叠起来的视效，个人觉得也还不错~
                //可与123行 c.drawRect 比较，只有bottom参数不一样，由于 child.getHeight() + child.getTop() < mTitleHeight，所以绘制区域是在不断的减小，有种折叠起来的感觉
             /*   c.clipRect(parent.getPaddingLeft(), parent.getPaddingTop(), parent.getRight() - parent.getPaddingRight(), parent.getPaddingTop() + child.getHeight() + child.getTop());*/

                //类似饿了么点餐时,商品列表的悬停头部切换“动画效果”
                //上滑时，将canvas上移 （y为负数） ,所以后面canvas 画出来的Rect和Text都上移了，有种切换的“动画”感觉
                c.translate(0, child.getHeight() + child.getTop() - mTitleHeight);
            }
        }
    }
    mPaint.setColor(COLOR_TITLE_BG);
    c.drawRect(parent.getPaddingLeft(), parent.getPaddingTop(), parent.getRight() - parent.getPaddingRight(), parent.getPaddingTop() + mTitleHeight, mPaint);
    mPaint.setColor(COLOR_TITLE_FONT);
    mPaint.getTextBounds(tag, 0, tag.length(), mBounds);
    c.drawText(tag, child.getPaddingLeft() + 30,
            parent.getPaddingTop() + mTitleHeight - (mTitleHeight / 2 - mBounds.height() / 2),
            mPaint);//滚动的过程中绘制title
    if (flag)
        c.restore();//恢复画布到之前保存的状态

}

Source File: ItemHeaderDecoration.java From AndroidSamples with Apache License 2.0

4 votes

/**
 * 可以绘制在内容的上面，覆盖内容
 *
 * @param c
 * @param parent
 * @param state
 */
@RequiresApi(api = Build.VERSION_CODES.KITKAT)
@Override
public void onDrawOver(Canvas c, final RecyclerView parent, RecyclerView.State state) {
    // 当前屏幕的第一个item
    int pos = ((LinearLayoutManager) (parent.getLayoutManager())).findFirstVisibleItemPosition();
    String tag = mDatas.get(pos).getTag();
    Log.e(TAG, "onDrawOver: pos：" + pos + "\ttag：" + tag);
    View child = parent.findViewHolderForLayoutPosition(pos).itemView;
    // 当发现下一个title顶上来的时候，将canvas向上平移，产生一种向上挤压的动画效果
    boolean flag = false;
    if ((pos + 1) < mDatas.size()) {
        String suspensionTag = mDatas.get(pos + 1).getTag();
        if (null != tag && !tag.equals(suspensionTag)) {
            if (child.getHeight() + child.getTop() < mTitleHeight) {
                c.save();
                flag = true;
                c.translate(0, child.getHeight() + child.getTop() - mTitleHeight);
            }
        }
    }

    // 绘制一个与列表中标题一样的东西（吸顶效果）
    View topTitleView = mInflater.inflate(R.layout.item_title, parent, false);
    TextView tvTitle = (TextView) topTitleView.findViewById(R.id.tv_title);
    tvTitle.setText("测试数据" + tag);
    int toDrawWidthSpec;//用于测量的widthMeasureSpec
    int toDrawHeightSpec;//用于测量的heightMeasureSpec
    RecyclerView.LayoutParams lp = (RecyclerView.LayoutParams) topTitleView.getLayoutParams();
    if (lp == null) {
        lp = new RecyclerView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);//这里是根据复杂布局layout的width height，new一个Lp
        // topTitleView.setLayoutParams(lp);
    }
    topTitleView.setLayoutParams(lp);
    if (lp.width == ViewGroup.LayoutParams.MATCH_PARENT) {
        //如果是MATCH_PARENT，则用父控件能分配的最大宽度和EXACTLY构建MeasureSpec。
        toDrawWidthSpec = View.MeasureSpec.makeMeasureSpec(parent.getWidth() - parent.getPaddingLeft() - parent.getPaddingRight(), View.MeasureSpec.EXACTLY);
    } else if (lp.width == ViewGroup.LayoutParams.WRAP_CONTENT) {
        //如果是WRAP_CONTENT，则用父控件能分配的最大宽度和AT_MOST构建MeasureSpec。
        toDrawWidthSpec = View.MeasureSpec.makeMeasureSpec(parent.getWidth() - parent.getPaddingLeft() - parent.getPaddingRight(), View.MeasureSpec.AT_MOST);
    } else {
        //否则则是具体的宽度数值，则用这个宽度和EXACTLY构建MeasureSpec。
        toDrawWidthSpec = View.MeasureSpec.makeMeasureSpec(lp.width, View.MeasureSpec.EXACTLY);
    }
    //高度同理
    if (lp.height == ViewGroup.LayoutParams.MATCH_PARENT) {
        toDrawHeightSpec = View.MeasureSpec.makeMeasureSpec(parent.getHeight() - parent.getPaddingTop() - parent.getPaddingBottom(), View.MeasureSpec.EXACTLY);
    } else if (lp.height == ViewGroup.LayoutParams.WRAP_CONTENT) {
        toDrawHeightSpec = View.MeasureSpec.makeMeasureSpec(parent.getHeight() - parent.getPaddingTop() - parent.getPaddingBottom(), View.MeasureSpec.AT_MOST);
    } else {
        toDrawHeightSpec = View.MeasureSpec.makeMeasureSpec(mTitleHeight, View.MeasureSpec.EXACTLY);
    }
    //依次调用 measure,layout,draw方法，将复杂头部显示在屏幕上。
    topTitleView.measure(toDrawWidthSpec, toDrawHeightSpec);
    topTitleView.layout(parent.getPaddingLeft(), parent.getPaddingTop(), parent.getPaddingLeft() + topTitleView.getMeasuredWidth(), parent.getPaddingTop() + topTitleView.getMeasuredHeight());
    topTitleView.draw(c);//Canvas默认在视图顶部，无需平移，直接绘制
    if (flag)
        c.restore();//恢复画布到之前保存的状态
    if (!TextUtils.equals(tag, currentTag)) {
        currentTag = tag;
        Integer integer = Integer.valueOf(currentTag);
        Log.e(TAG, "onDrawOver: " + integer);
        mCheckListener.check(integer);
    }

}

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