Android TV端的（RecyclerView）水平滚动焦点错乱问题 _RecyclerView

【Android TV端的（RecyclerView）水平滚动焦点错乱问题】不操千曲而后晓声，观千剑而后识器。这篇文章主要讲述Android TV端的（RecyclerView）水平滚动焦点错乱问题相关的知识，希望能为你提供帮助。

package com.hhzt.iptv.ui.customview;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Rect;
import android.os.Build;
import android.support.v4.view.ViewCompat;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.AttributeSet;
import android.util.Log;
import android.view.FocusFinder;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.View;

import com.hhzt.iptv.R;
import com.hhzt.iptv.lvb_w.interfaces.OnInterceptListener;
import com.hhzt.iptv.lvb_w.utils.VirturlKeyPadCtr;

/**
* Created by Administrator on 2017/6/7.
*/

public class TvRecyclerView extends RecyclerView {
private static final String TAG = "TvRecyclerView";

private int position;

//焦点是否居中
private boolean mSelectedItemCentered;

private int mSelectedItemOffsetStart;

private int mSelectedItemOffsetEnd;

//分页的时候使用
private int mLoadMoreBeforehandCount = 0;

public TvRecyclerView(Context context) {
this(context, null);
}

public TvRecyclerView(Context context, AttributeSet attrs) {
this(context, attrs, -1);
}

public TvRecyclerView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context, attrs, defStyle);
}

private void init(Context context, AttributeSet attrs, int defStyle) {
initView();
initAttr(context, attrs);
}

private void initView() {
setDescendantFocusability(FOCUS_AFTER_DESCENDANTS);
setHasFixedSize(true);
setWillNotDraw(true);
setOverScrollMode(View.OVER_SCROLL_NEVER);
setChildrenDrawingOrderEnabled(true);

setClipChildren(false);
setClipToPadding(false);

setClickable(false);
setFocusable(true);
setFocusableInTouchMode(true);
/**
防止RecyclerView刷新时焦点不错乱bug的步骤如下:
(1)adapter执行setHasStableIds(true)方法
(2)重写getItemId()方法,让每个view都有各自的id
(3)RecyclerView的动画必须去掉
*/
setItemAnimator(null);
}

private void initAttr(Context context, AttributeSet attrs) {
if (attrs != null) {
final TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.TvRecyclerView);
/**
* 如果是towWayView的layoutManager
*/
final String name = a.getString(R.styleable.TvRecyclerView_tv_layoutManager);

mSelectedItemCentered = a.getBoolean(R.styleable.TvRecyclerView_tv_selectedItemCentered, false);

mLoadMoreBeforehandCount = a.getInteger(R.styleable.TvRecyclerView_tv_loadMoreBeforehandCount, 0);

mSelectedItemOffsetStart = a.getDimensionPixelSize(R.styleable.TvRecyclerView_tv_selectedItemOffsetStart, 0);

mSelectedItemOffsetEnd = a.getDimensionPixelSize(R.styleable.TvRecyclerView_tv_selectedItemOffsetEnd, 0);

a.recycle();
}
}

private int getFreeWidth() {
return getWidth() - getPaddingLeft() - getPaddingRight();
}

private int getFreeHeight() {
return getHeight() - getPaddingTop() - getPaddingBottom();
}

@Override
protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) {
super.onFocusChanged(gainFocus, direction, previouslyFocusedRect);
}

@Override
public boolean hasFocus() {
return super.hasFocus();
}

@Override
public boolean isInTouchMode() {
// 解决4.4版本抢焦点的问题
if (Build.VERSION.SDK_INT == 19) {
return !(hasFocus() & & !super.isInTouchMode());
} else {
return super.isInTouchMode();
}

//return super.isInTouchMode();
}

@Override
public void requestChildFocus(View child, View focused) {

if (null != child) {
if (mSelectedItemCentered) {
mSelectedItemOffsetStart = !isVertical() ? (getFreeWidth() - child.getWidth()) : (getFreeHeight() - child.getHeight());
mSelectedItemOffsetStart /= 2;
mSelectedItemOffsetEnd = mSelectedItemOffsetStart;
}
}
super.requestChildFocus(child, focused);
}

@Override
public boolean requestChildRectangleOnScreen(View child, Rect rect, boolean immediate) {
final int parentLeft = getPaddingLeft();
final int parentRight = getWidth() - getPaddingRight();

final int parentTop = getPaddingTop();
final int parentBottom = getHeight() - getPaddingBottom();

final int childLeft = child.getLeft() + rect.left;
final int childTop = child.getTop() + rect.top;

final int childRight = childLeft + rect.width();
final int childBottom = childTop + rect.height();

final int offScreenLeft = Math.min(0, childLeft - parentLeft - mSelectedItemOffsetStart);
final int offScreenRight = Math.max(0, childRight - parentRight + mSelectedItemOffsetEnd);

final int offScreenTop = Math.min(0, childTop - parentTop - mSelectedItemOffsetStart);
final int offScreenBottom = Math.max(0, childBottom - parentBottom + mSelectedItemOffsetEnd);

final boolean canScrollHorizontal = getLayoutManager().canScrollHorizontally();
final boolean canScrollVertical = getLayoutManager().canScrollVertically();

// Favor the "start" layout direction over the end when bringing one side or the other
// of a large rect into view. If we decide to bring in end because start is already
// visible, limit the scroll such that start won‘t go out of bounds.
final int dx;
if (canScrollHorizontal) {
if (ViewCompat.getLayoutDirection(this) == ViewCompat.LAYOUT_DIRECTION_RTL) {
dx = offScreenRight != 0 ? offScreenRight
: Math.max(offScreenLeft, childRight - parentRight);
} else {
dx = offScreenLeft != 0 ? offScreenLeft
: Math.min(childLeft - parentLeft, offScreenRight);
}
} else {
dx = 0;
}

// Favor bringing the top into view over the bottom. If top is already visible and
// we should scroll to make bottom visible, make sure top does not go out of bounds.
final int dy;
if (canScrollVertical) {
dy = offScreenTop != 0 ? offScreenTop : Math.min(childTop - parentTop, offScreenBottom);
} else {
dy = 0;
}

if (dx != 0 || dy != 0) {
if (immediate) {
scrollBy(dx, dy);
} else {
smoothScrollBy(dx, dy);
}
// 重绘是为了选中item置顶，具体请参考getChildDrawingOrder方法
postInvalidate();
return true;
}

return false;
}

@Override
public int getBaseline() {
return -1;
}

public int getSelectedItemOffsetStart() {
return mSelectedItemOffsetStart;
}

public int getSelectedItemOffsetEnd() {
return mSelectedItemOffsetEnd;
}

@Override
public void setLayoutManager(LayoutManager layout) {
super.setLayoutManager(layout);
}

/**
* 判断是垂直，还是横向.
*/
private boolean isVertical() {
LayoutManager manager = getLayoutManager();
if (manager != null) {
LinearLayoutManager layout = (LinearLayoutManager) getLayoutManager();
return layout.getOrientation() == LinearLayoutManager.VERTICAL;

}
return false;
}

/**
* 设置选中的Item距离开始或结束的偏移量；
* 与滚动方向有关；
* 与setSelectedItemAtCentered()方法二选一
*
* @param offsetStart
* @param offsetEnd从结尾到你移动的位置.
*/
public void setSelectedItemOffset(int offsetStart, int offsetEnd) {
setSelectedItemAtCentered(false);
mSelectedItemOffsetStart = offsetStart;
mSelectedItemOffsetEnd = offsetEnd;
}

/**
* 设置选中的Item居中；
* 与setSelectedItemOffset()方法二选一
*
* @param isCentered
*/
public void setSelectedItemAtCentered(boolean isCentered) {
this.mSelectedItemCentered = isCentered;
}

@Override
protected int getChildDrawingOrder(int childCount, int i) {
View view = getFocusedChild();
if (null != view) {

position = getChildAdapterPosition(view) - getFirstVisiblePosition();
if (position < 0) {
return i;
} else {
if (i == childCount - 1) {//这是最后一个需要刷新的item
if (position > i) {
position = i;
}
return position;
}
if (i == position) {//这是原本要在最后一个刷新的item
return childCount - 1;
}
}
}
return i;
}

public int getFirstVisiblePosition() {
if (getChildCount() == 0)
return 0;
else
return getChildAdapterPosition(getChildAt(0));
}

public int getLastVisiblePosition() {
final int childCount = getChildCount();
if (childCount == 0)
return 0;
else
return getChildAdapterPosition(getChildAt(childCount - 1));
}

/***********
* 按键加载更多 start
**********/

private OnLoadMoreListener mOnLoadMoreListener;

public interface OnLoadMoreListener {
void onLoadMore();
}

public void setOnLoadMoreListener(OnLoadMoreListener onLoadMoreListener) {
this.mOnLoadMoreListener = onLoadMoreListener;
}

private OnInterceptListener mInterceptLister;

public void setOnInterceptListener(OnInterceptListener listener) {
this.mInterceptLister = listener;
}

/**
* 设置为0，这样可以防止View获取焦点的时候，ScrollView自动滚动到焦点View的位置
*/

protected int computeScrollDeltaToGetChildRectOnScreen(Rect rect) {
return 0;
}

@Override
public void onScrollStateChanged(int state) {
if (state == SCROLL_STATE_IDLE) {
// 加载更多回调
if (null != mOnLoadMoreListener) {
if (getLastVisiblePosition() > = getAdapter().getItemCount() - (1 + mLoadMoreBeforehandCount)) {
mOnLoadMoreListener.onLoadMore();
}
}
}
super.onScrollStateChanged(state);
}

@Override
public boolean dispatchKeyEvent(KeyEvent event) {
if (mInterceptLister != null & & mInterceptLister.onIntercept(event)) {
return true;
}

boolean result = super.dispatchKeyEvent(event);
View focusView = this.getFocusedChild();
if (focusView == null) {
return result;
} else {

int dy = 0;
int dx = 0;
if (getChildCount() > 0) {
View firstView = this.getChildAt(0);
dy = firstView.getHeight();
dx = firstView.getWidth();
}
if (event.getAction() == KeyEvent.ACTION_UP) {
return true;
} else {
switch (event.getKeyCode()) {
case KeyEvent.KEYCODE_DPAD_RIGHT:
if(VirturlKeyPadCtr.isFastDoubleClick()){
return true;
}else {
View rightView = FocusFinder.getInstance().findNextFocus(this, focusView, View.FOCUS_RIGHT);
Log.i(TAG, "rightView is null:" + (rightView == null));
if (rightView != null) {
rightView.requestFocus();
return true;
} else {
this.smoothScrollBy(dx, 0);
return true;
}
}
case KeyEvent.KEYCODE_DPAD_LEFT:
View leftView = FocusFinder.getInstance().findNextFocus(this, focusView, View.FOCUS_LEFT);
Log.i(TAG, "leftView is null:" + (leftView == null));
if (leftView != null) {
leftView.requestFocus();
return true;
} else {
this.smoothScrollBy(-dx, 0);
return true;
}
case KeyEvent.KEYCODE_DPAD_DOWN:
View downView = FocusFinder.getInstance().findNextFocus(this, focusView, View.FOCUS_DOWN);
Log.i(TAG, " downView is null:" + (downView == null));
if (downView != null) {
downView.requestFocus();
return true;
} else {
this.smoothScrollBy(0, dy);
return true;
}
case KeyEvent.KEYCODE_DPAD_UP:
View upView = FocusFinder.getInstance().findNextFocus(this, focusView, View.FOCUS_UP);
Log.i(TAG, "upView is null:" + (upView == null));
if (event.getAction() == KeyEvent.ACTION_UP) {
return true;
} else {
if (upView != null) {
upView.requestFocus();
return true;
} else {
this.smoothScrollBy(0, -dy);
return true;
}

}
}

}

}
return result;
}

@Override
public boolean onInterceptTouchEvent(MotionEvent e) {
return super.onInterceptTouchEvent(e);
}

/**
* 设置默认选中.
*/

public void setSelectedPosition(int pos) {
this.smoothScrollToPosition(pos);
}

//防止Activity时,RecyclerView崩溃
@Override
protected void onDetachedFromWindow() {
if (getLayoutManager() != null) {
super.onDetachedFromWindow();
}
}

/**
* 是否是最右边的item，如果是竖向，表示右边，如果是横向表示下边
*
* @param childPosition
* @return
*/
public boolean isRightEdge(int childPosition) {
LayoutManager layoutManager = getLayoutManager();

if (layoutManager instanceof GridLayoutManager) {

GridLayoutManager gridLayoutManager = (GridLayoutManager) layoutManager;
GridLayoutManager.SpanSizeLookup spanSizeLookUp = gridLayoutManager.getSpanSizeLookup();

int totalSpanCount = gridLayoutManager.getSpanCount();
int totalItemCount = gridLayoutManager.getItemCount();
int childSpanCount = 0;

for (int i = 0; i < = childPosition; i++) {
childSpanCount += spanSizeLookUp.getSpanSize(i);
}
if (isVertical()) {
if (childSpanCount % gridLayoutManager.getSpanCount() == 0) {
return true;
}
} else {
int lastColumnSize = totalItemCount % totalSpanCount;
if (lastColumnSize == 0) {
lastColumnSize = totalSpanCount;
}
if (childSpanCount > totalItemCount - lastColumnSize) {
return true;
}
}

} else if (layoutManager instanceof LinearLayoutManager) {
if (isVertical()) {
return true;
}else{
return childPosition == getLayoutManager().getItemCount() - 1;
}
}

return false;
}

/**
* 是否是最左边的item，如果是竖向，表示左方，如果是横向，表示上边
*
* @param childPosition
* @return
*/
public boolean isLeftEdge(int childPosition) {
LayoutManager layoutManager = getLayoutManager();
if (layoutManager instanceof GridLayoutManager) {
GridLayoutManager gridLayoutManager = (GridLayoutManager) layoutManager;
GridLayoutManager.SpanSizeLookup spanSizeLookUp = gridLayoutManager.getSpanSizeLookup();

int totalSpanCount = gridLayoutManager.getSpanCount();
int childSpanCount = 0;
for (int i = 0; i < = childPosition; i++) {
childSpanCount += spanSizeLookUp.getSpanSize(i);
}
if (isVertical()) {
if (childSpanCount % gridLayoutManager.getSpanCount() == 1) {
return true;
}
} else {
if (childSpanCount < = totalSpanCount) {
return true;
}
}

} else if (layoutManager instanceof LinearLayoutManager) {
if (isVertical()) {
return true;
} else {
return childPosition == 0;
}

}

return false;
}

/**
* 是否是最上边的item，以recyclerview的方向做参考
*
* @param childPosition
* @return
*/
public boolean isTopEdge(int childPosition) {
LayoutManager layoutManager = getLayoutManager();
if (layoutManager instanceof GridLayoutManager) {
GridLayoutManager gridLayoutManager = (GridLayoutManager) layoutManager;
GridLayoutManager.SpanSizeLookup spanSizeLookUp = gridLayoutManager.getSpanSizeLookup();

int totalSpanCount = gridLayoutManager.getSpanCount();

int childSpanCount = 0;
for (int i = 0; i < = childPosition; i++) {
childSpanCount += spanSizeLookUp.getSpanSize(i);
}

if (isVertical()) {
if (childSpanCount < = totalSpanCount) {
return true;
}
} else {
if (childSpanCount % totalSpanCount == 1) {
return true;
}
}

} else if (layoutManager instanceof LinearLayoutManager) {
if (isVertical()) {
return childPosition == 0;
} else {
return true;
}

}

return false;
}

/**
* 是否是最下边的item，以recyclerview的方向做参考
*
* @param childPosition
* @return
*/
public boolean isBottomEdge(int childPosition) {
LayoutManager layoutManager = getLayoutManager();
if (layoutManager instanceof GridLayoutManager) {
GridLayoutManager gridLayoutManager = (GridLayoutManager) layoutManager;
GridLayoutManager.SpanSizeLookup spanSizeLookUp = gridLayoutManager.getSpanSizeLookup();
int itemCount = gridLayoutManager.getItemCount();
int childSpanCount = 0;
int totalSpanCount = gridLayoutManager.getSpanCount();
for (int i = 0; i < = childPosition; i++) {
childSpanCount += spanSizeLookUp.getSpanSize(i);
}
if (isVertical()) {
//最后一行item的个数
int lastRowCount = itemCount % totalSpanCount;
if (lastRowCount == 0) {
lastRowCount = gridLayoutManager.getSpanCount();
}
if (childSpanCount > itemCount - lastRowCount) {
return true;
}
} else {
if (childSpanCount % totalSpanCount == 0) {
return true;
}
}

} else if (layoutManager instanceof LinearLayoutManager) {
if (isVertical()) {
return childPosition == getLayoutManager().getItemCount() - 1;
} else {
return true;
}

}
return false;
}

}
/*延时焦点的移动*/

public static boolean isFastDoubleClick() {
long time = System.currentTimeMillis();
long timeD = time - lastClickTime;
if ( 0 < timeD & & timeD < 200) {
return true;
}
lastClickTime = time;
return false;
}