效果图：
整个界面只用了RecyclerView实现，实现拖拽功能主要用到的了ItemTouchHelper类，添加和删除功能主要用到了位移动画实现位移效果。下面我们看看每一个相关的代码类；
- ClassifyAdapter.java
public class ClassifyActivity extends AppCompatActivity {
@BindView(R.id.recy)
RecyclerView mRecy;
private List items = new ArrayList<>();
private List otherItems = new ArrayList<>();
private ClassifyAdapter adapter;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_classify);
ButterKnife.bind(this);
setTitle("拖拽排序，点击删除");
initData();
init();
}
private void init() {
GridLayoutManager manager = new GridLayoutManager(this, 4);
mRecy.setLayoutManager(manager);
ItemDragHelperCallback callback = new ItemDragHelperCallback();
final ItemTouchHelper helper = new ItemTouchHelper(callback);
//将ItemTouchHelper和RecyclerView建立关联
helper.attachToRecyclerView(mRecy);
adapter = new ClassifyAdapter(this, helper, items, otherItems, 1);
manager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
@Override
public int getSpanSize(int position) {
int viewType = adapter.getItemViewType(position);
//从效果可知，当是两个头布局的时候要占据一行
return viewType == ClassifyAdapter.TYPE_MY || viewType == ClassifyAdapter.TYPE_OTHER ? 1 : 4;
}
});
mRecy.setAdapter(adapter);
adapter.setOnMyChannelItemClickListener(new ClassifyAdapter.OnMyChannelItemClickListener() {
@Override
public void onItemClick(View v, int position) {
Toast.makeText(ClassifyActivity.this, "要跳转了", Toast.LENGTH_SHORT).show();
}
});
adapter.setmCompleteListener(new ClassifyAdapter.OnCompleteListener() {
@Override
public void onComplete(List list) {
Toast.makeText(ClassifyActivity.this, "完成了", Toast.LENGTH_SHORT).show();
}
});
}
private void initData() {
items.add(new TagBean("推荐", 1));
items.add(new TagBean("视频", 2));
items.add(new TagBean("图片", 3));
items.add(new TagBean("娱乐", 4));
items.add(new TagBean("问答", 5));
...
}
}
上面代码中我们主要关注的就是ItemDragHelperCallback和ClassifyAdapter，其他的代码中都有详细注释。
- ItemDragHelperCallback.java
public class ItemDragHelperCallback extends ItemTouchHelper.Callback {
private static String TAG = ItemDragHelperCallback.class.getSimpleName();
/**
* 开始拖拽排序时被调用
* @param recyclerView
* @param viewHolder
* @return
*/
@Override
public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
Log.e(TAG,"getMovementFlags");
int dragFlags;
//针对第一个不能拖拽
if (viewHolder.getAdapterPosition() == 1) {
return 0;
}
RecyclerView.LayoutManager manager = recyclerView.getLayoutManager();
if (manager instanceof GridLayoutManager || manager instanceof StaggeredGridLayoutManager) {
dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
} else {
dragFlags = ItemTouchHelper.UP | ItemTouchHelper.DOWN;
}
// 如果想支持滑动(删除)操作, swipeFlags = ItemTouchHelper.START | ItemTouchHelper.END
int swipeFlags = 0;
return makeMovementFlags(dragFlags, swipeFlags);
}
/**
* 在拖拽移动过程中被调用
* @param recyclerView
* @param viewHolder
* @param target
* @return
*/
@Override
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
Log.e(TAG,"onMove");
// 不同Type之间不可移动
if (viewHolder.getItemViewType() != target.getItemViewType()) {
return false;
}
//如果目标点为第一个 也不能拖拽过去
if(target.getAdapterPosition()==1){
return false;
}
//ClassifyAdapter实现了OnItemMoveListener接口
if (recyclerView.getAdapter() instanceof OnItemMoveListener) {
OnItemMoveListener listener = ((OnItemMoveListener) recyclerView.getAdapter());
listener.onItemMove(viewHolder.getAdapterPosition(), target.getAdapterPosition());
}
return true;
}
@Override
public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
}
/**
* 在开始拖拽排序和结束拖拽时被调用
* @param viewHolder
* @param actionState
*/
@Override
public void onSelectedChanged(RecyclerView.ViewHolder viewHolder, int actionState) {
Log.e(TAG,"onSelectedChanged");
// 不在闲置状态
if (actionState != ItemTouchHelper.ACTION_STATE_IDLE) {
//我的频道ViewHolder实现了了OnDragVHListener接口
if (viewHolder instanceof OnDragVHListener) {
OnDragVHListener itemViewHolder = (OnDragVHListener) viewHolder;
itemViewHolder.onItemSelected();
}
}
super.onSelectedChanged(viewHolder, actionState);
}
/**
* 排序完成后调用
* @param recyclerView
* @param viewHolder
*/
@Override
public void clearView(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
Log.e(TAG,"clearView");
//我的频道ViewHolder实现了了OnDragVHListener接口
if (viewHolder instanceof OnDragVHListener) {
OnDragVHListener itemViewHolder = (OnDragVHListener) viewHolder;
itemViewHolder.onItemFinish();
}
super.clearView(recyclerView, viewHolder);
}
@Override
public boolean isLongPressDragEnabled() {
// 不支持长按拖拽功能 手动控制
return false;
}
@Override
public boolean isItemViewSwipeEnabled() {
// 不支持滑动功能
return false;
}
}
从上面除了注释，我们还要了解的是OnItemMoveListener和OnDragVHListener这两个接口。
- OnItemMoveListener.java
public interface OnItemMoveListener {
//在条目移动时，被调用
void onItemMove(int fromPosition, int toPosition);
}
- OnDragVHListener.java
public interface OnDragVHListener {
/**
* Item被选中时触发
*/
void onItemSelected();
/**
* Item在拖拽结束/滑动结束后触发
*/
void onItemFinish();
}
从ItemDragHelperCallback 中我们发现这两个接口的所有方法都被调用了，那么具体实现方法逻辑的代码在哪呢，下面就是我们的重头戏adapter了。
- ClassAdapter
public class ClassifyAdapter extends RecyclerView.Adapter implements OnItemMoveListener {
// 我的频道 标题部分
public static final int TYPE_MY_CHANNEL_HEADER = 0;
// 我的频道
public static final int TYPE_MY = 1;
// 其他频道 标题部分
public static final int TYPE_OTHER_CHANNEL_HEADER = 2;
// 其他频道
public static final int TYPE_OTHER = 3;
// 我的频道之前的header数量 该demo中 即标题部分 为 1
private static final int COUNT_PRE_MY_HEADER = 1;
// 其他频道之前的header数量 该demo中 即标题部分 为 COUNT_PRE_MY_HEADER + 1
private static final int COUNT_PRE_OTHER_HEADER = COUNT_PRE_MY_HEADER + 1;
private static final long ANIM_TIME = 360L;
private final Context mContext;
// touch 点击开始时间
private long startTime;
// touch 间隔时间 用于分辨是否是 "点击"
private static final long SPACE_TIME = 100;
private LayoutInflater mInflater;
private ItemTouchHelper mItemTouchHelper;
// 是否为 编辑 模式
private boolean isEditMode;
private List mMyChannelItems = new ArrayList<>();
private List mOtherChannelItems = new ArrayList<>();
// 我的频道点击事件
private OnMyChannelItemClickListener mChannelItemClickListener;
private OnCompleteListener mCompleteListener;
private int selectedType;
public ClassifyAdapter(Context context, ItemTouchHelper helper, List mMyChannelItems,
List mOtherChannelItems, int selectedType) {
this.mContext = context;
this.mInflater = LayoutInflater.from(context);
this.mItemTouchHelper = helper;
this.mMyChannelItems = mMyChannelItems;
this.mOtherChannelItems = mOtherChannelItems;
this.selectedType = selectedType;
}
/**
* 根据效果图我们知道该RecyclerView总共包含四种布局
*
* @param position
* @return
*/
@Override
public int getItemViewType(int position) {
if (mMyChannelItems == null && position == 1) {
return TYPE_OTHER_CHANNEL_HEADER;
}
if (position == 0) { // 我的频道 标题部分
return TYPE_MY_CHANNEL_HEADER;
} else if (position == mMyChannelItems.size() + 1) {// 其他频道 标题部分
return TYPE_OTHER_CHANNEL_HEADER;
} else if (position > 0 && position < mMyChannelItems.size() + 1) {
return TYPE_MY;
} else {
return TYPE_OTHER;
}
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(final ViewGroup parent, int viewType) {
final View view;
switch (viewType) {
case TYPE_MY_CHANNEL_HEADER://我的频道的头布局
view = mInflater.inflate(R.layout.item_my_channel_header, parent, false);
final MyChannelHeaderViewHolder holder = new MyChannelHeaderViewHolder(view);
holder.tvBtnEdit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (!isEditMode) {
startEditMode((RecyclerView) parent);
holder.tvBtnEdit.setText(R.string.finish);
holder.tvDescription.setText("拖拽可以排序");
} else {
cancelEditMode((RecyclerView) parent);
holder.tvBtnEdit.setText(R.string.edit);
holder.tvDescription.setText("点击进入频道");
mCompleteListener.onComplete(mMyChannelItems);
}
}
});
return holder;
case TYPE_MY://我的频道的条目布局
view = mInflater.inflate(R.layout.item_my, parent, false);
final MyViewHolder myHolder = new MyViewHolder(view);
myHolder.imgEdit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
clickMyChannelItem(myHolder, parent, v);
}
});
myHolder.textView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(final View v) {
clickMyChannelItem(myHolder, parent, v);
}
});
//我的频道条目的长按事件
myHolder.textView.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(final View v) {
if (!isEditMode) {
RecyclerView recyclerView = ((RecyclerView) parent);
startEditMode(recyclerView);
// header 按钮文字 改成 "完成"
View view = recyclerView.getChildAt(0);
if (view == recyclerView.getLayoutManager().findViewByPosition(0)) {
TextView tvBtnEdit = (TextView) view.findViewById(R.id.tv_btn_edit);
TextView tvDescription = (TextView) view.findViewById(R.id.tv_description);
tvBtnEdit.setText(R.string.finish);
tvDescription.setText("拖拽可以排序");
}
}
//调用ItemTouchHelper的开始拖拽方法
mItemTouchHelper.startDrag(myHolder);
return true;
}
});
myHolder.textView.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
if (isEditMode) {
switch (MotionEventCompat.getActionMasked(event)) {
case MotionEvent.ACTION_DOWN:
startTime = System.currentTimeMillis();
break;
case MotionEvent.ACTION_MOVE:
if (System.currentTimeMillis() - startTime > SPACE_TIME) {
//调用ItemTouchHelper的开始拖拽方法
mItemTouchHelper.startDrag(myHolder);
}
break;
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:
startTime = 0;
break;
}
}
return false;
}
});
return myHolder;
case TYPE_OTHER_CHANNEL_HEADER://其他频道的头布局
view = mInflater.inflate(R.layout.item_other_channel_header, parent, false);
return new RecyclerView.ViewHolder(view) {
};
case TYPE_OTHER://其他频道的条目布局
view = mInflater.inflate(R.layout.item_other, parent, false);
final OtherViewHolder otherHolder = new OtherViewHolder(view);
//其他频道条目的点击事件
otherHolder.textView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
RecyclerView recyclerView = ((RecyclerView) parent);
RecyclerView.LayoutManager manager = recyclerView.getLayoutManager();
int currentPiosition = otherHolder.getAdapterPosition();
// 如果RecyclerView滑动到底部,移动的目标位置的y轴 - height
View currentView = manager.findViewByPosition(currentPiosition);
// 目标位置的前一个item 即当前MyChannel的最后一个
View preTargetView = manager.findViewByPosition(mMyChannelItems.size() - 1 + COUNT_PRE_MY_HEADER);
// 如果targetView不在屏幕内,则为-1 此时不需要添加动画,因为此时notifyItemMoved自带一个向目标移动的动画
// 如果在屏幕内,则添加一个位移动画
if (recyclerView.indexOfChild(preTargetView) >= 0) {
Logger.e("从其他频道到我的频道，用到了自定义动画");
int targetX = preTargetView.getLeft();
int targetY = preTargetView.getTop();
int targetPosition = mMyChannelItems.size() - 1 + COUNT_PRE_OTHER_HEADER;
GridLayoutManager gridLayoutManager = ((GridLayoutManager) manager);
int spanCount = gridLayoutManager.getSpanCount();
// target 在最后一行第一个
if ((targetPosition - COUNT_PRE_MY_HEADER) % spanCount == 0) {
View targetView = manager.findViewByPosition(targetPosition);
targetX = targetView.getLeft();
targetY = targetView.getTop();
} else {
targetX += preTargetView.getWidth();
// 最后一个item可见
if (gridLayoutManager.findLastVisibleItemPosition() == getItemCount() - 1) {
// 最后的item在最后一行第一个位置
if ((getItemCount() - 1 - mMyChannelItems.size() - COUNT_PRE_OTHER_HEADER) % spanCount == 0) {
// RecyclerView实际高度 > 屏幕高度 && RecyclerView实际高度 < 屏幕高度 + item.height
int firstVisiblePostion = gridLayoutManager.findFirstVisibleItemPosition();
if (firstVisiblePostion == 0) {
// FirstCompletelyVisibleItemPosition == 0 即 内容不满一屏幕 , targetY值不需要变化
// // FirstCompletelyVisibleItemPosition != 0 即 内容满一屏幕 并且 可滑动 , targetY值 + firstItem.getTop
if (gridLayoutManager.findFirstCompletelyVisibleItemPosition() != 0) {
int offset = (-recyclerView.getChildAt(0).getTop()) - recyclerView.getPaddingTop();
targetY += offset;
}
} else { // 在这种情况下 并且 RecyclerView高度变化时(即可见第一个item的 position != 0),
// 移动后, targetY值 + 一个item的高度
targetY += preTargetView.getHeight();
}
}
} else {
System.out.println("current--No");
}
}
// 如果当前位置是otherChannel可见的最后一个
// 并且 当前位置不在grid的第一个位置
// 并且 目标位置不在grid的第一个位置
// 则 需要延迟250秒 notifyItemMove , 这是因为这种情况 , 并不触发ItemAnimator , 会直接刷新界面
// 导致我们的位移动画刚开始,就已经notify完毕,引起不同步问题
if (currentPiosition == gridLayoutManager.findLastVisibleItemPosition()
&& (currentPiosition - mMyChannelItems.size() - COUNT_PRE_OTHER_HEADER) % spanCount != 0
&& (targetPosition - COUNT_PRE_MY_HEADER) % spanCount != 0) {
moveOtherToMyWithDelay(otherHolder);
} else {
moveOtherToMy(otherHolder);
}
startAnimation(recyclerView, currentView, targetX, targetY);
} else {
moveOtherToMy(otherHolder);
}
}
});
return otherHolder;
}
return null;
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if (holder instanceof MyViewHolder) {
MyViewHolder myHolder = (MyViewHolder) holder;
myHolder.textView.setText(mMyChannelItems.get(position - COUNT_PRE_MY_HEADER).getText());
if (selectedType == -1 && position == 1) {
myHolder.textView.setTextColor(Color.RED);
}
if (mMyChannelItems.get(position - COUNT_PRE_MY_HEADER).getType() == selectedType) {
myHolder.textView.setTextColor(Color.RED);
} else {
myHolder.textView.setTextColor(mContext.getResources().getColor(R.color.channel_item_color));
}
if (isEditMode) {
myHolder.imgEdit.setVisibility(View.VISIBLE);
} else {
myHolder.imgEdit.setVisibility(View.INVISIBLE);
}
} else if (holder instanceof OtherViewHolder) {
((OtherViewHolder) holder).textView.setText(mOtherChannelItems.get(position - mMyChannelItems.size() - COUNT_PRE_OTHER_HEADER).getText());
} else if (holder instanceof MyChannelHeaderViewHolder) {
MyChannelHeaderViewHolder headerHolder = (MyChannelHeaderViewHolder) holder;
if (isEditMode) {
headerHolder.tvBtnEdit.setText(R.string.finish);
headerHolder.tvDescription.setText("拖拽可以排序");
} else {
headerHolder.tvBtnEdit.setText(R.string.edit);
headerHolder.tvDescription.setText("点击进入频道");
}
}
}
@Override
public int getItemCount() {
// 我的频道 标题 + 我的频道.size + 其他频道 标题 + 其他频道.size
if (mMyChannelItems != null && mOtherChannelItems != null) {
return mMyChannelItems.size() + mOtherChannelItems.size() + COUNT_PRE_OTHER_HEADER;
} else {
return COUNT_PRE_OTHER_HEADER;
}
}
/**
* 开始增删动画
*/
private void startAnimation(RecyclerView recyclerView, final View currentView, float targetX, float targetY) {
final ViewGroup viewGroup = (ViewGroup) recyclerView.getParent();
final ImageView mirrorView = addMirrorView(viewGroup, recyclerView, currentView);
Animation animation = getTranslateAnimator(
targetX - currentView.getLeft(), targetY - currentView.getTop());
currentView.setVisibility(View.INVISIBLE);
mirrorView.startAnimation(animation);
animation.setAnimationListener(new Animation.AnimationListener() {
@Override
public void onAnimationStart(Animation animation) {
}
@Override
public void onAnimationEnd(Animation animation) {
viewGroup.removeView(mirrorView);
if (currentView.getVisibility() == View.INVISIBLE) {
currentView.setVisibility(View.VISIBLE);
}
}
@Override
public void onAnimationRepeat(Animation animation) {
}
});
}
/**
* 我的频道 移动到 其他频道
*
* @param myHolder
*/
private void moveMyToOther(MyViewHolder myHolder) {
int position = myHolder.getAdapterPosition();
int startPosition = position - COUNT_PRE_MY_HEADER;
if (startPosition > mMyChannelItems.size() - 1) {
return;
}
TagBean item = mMyChannelItems.get(startPosition);
mMyChannelItems.remove(startPosition);
mOtherChannelItems.add(0, item);
notifyItemMoved(position, mMyChannelItems.size() + COUNT_PRE_OTHER_HEADER);
}
/**
* 其他频道 移动到 我的频道
*
* @param otherHolder
*/
private void moveOtherToMy(OtherViewHolder otherHolder) {
int position = processItemRemoveAdd(otherHolder);
if (position == -1) {
return;
}
notifyItemMoved(position, mMyChannelItems.size() - 1 + COUNT_PRE_MY_HEADER);
}
/**
* 其他频道 移动到 我的频道 伴随延迟
*
* @param otherHolder
*/
private void moveOtherToMyWithDelay(OtherViewHolder otherHolder) {
final int position = processItemRemoveAdd(otherHolder);
if (position == -1) {
return;
}
delayHandler.postDelayed(new Runnable() {
@Override
public void run() {
notifyItemMoved(position, mMyChannelItems.size() - 1 + COUNT_PRE_MY_HEADER);
}
}, ANIM_TIME);
}
private Handler delayHandler = new Handler();
private int processItemRemoveAdd(OtherViewHolder otherHolder) {
int position = otherHolder.getAdapterPosition();
int startPosition = position - mMyChannelItems.size() - COUNT_PRE_OTHER_HEADER;
if (startPosition > mOtherChannelItems.size() - 1) {
return -1;
}
TagBean item = mOtherChannelItems.get(startPosition);
mOtherChannelItems.remove(startPosition);
mMyChannelItems.add(item);
return position;
}
/**
* 添加需要移动的 镜像View
*/
private ImageView addMirrorView(ViewGroup parent, RecyclerView recyclerView, View view) {
/**
* 我们要获取cache首先要通过setDrawingCacheEnable方法开启cache，然后再调用getDrawingCache方法就可以获得view的cache图片了。
buildDrawingCache方法可以不用调用，因为调用getDrawingCache方法时，若果cache没有建立，系统会自动调用buildDrawingCache方法生成cache。
若想更新cache, 必须要调用destoryDrawingCache方法把旧的cache销毁，才能建立新的。
当调用setDrawingCacheEnabled方法设置为false, 系统也会自动把原来的cache销毁。
*/
view.destroyDrawingCache();
view.setDrawingCacheEnabled(true);
final ImageView mirrorView = new ImageView(recyclerView.getContext());
Bitmap bitmap = Bitmap.createBitmap(view.getDrawingCache());
mirrorView.setImageBitmap(bitmap);
view.setDrawingCacheEnabled(false);
int[] locations = new int[2];
view.getLocationOnScreen(locations);
int[] parenLocations = new int[2];
recyclerView.getLocationOnScreen(parenLocations);
FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(bitmap.getWidth(), bitmap.getHeight());
params.setMargins(locations[0], locations[1] - parenLocations[1], 0, 0);
parent.addView(mirrorView, params);
return mirrorView;
}
@Override
public void onItemMove(int fromPosition, int toPosition) {
TagBean item = mMyChannelItems.get(fromPosition - COUNT_PRE_MY_HEADER);
mMyChannelItems.remove(fromPosition - COUNT_PRE_MY_HEADER);
mMyChannelItems.add(toPosition - COUNT_PRE_MY_HEADER, item);
notifyItemMoved(fromPosition, toPosition);
}
/**
* 开启编辑模式
*
* @param parent
*/
private void startEditMode(RecyclerView parent) {
isEditMode = true;
int visibleChildCount = parent.getChildCount();
for (int i = 2; i < visibleChildCount; i++) {
View view = parent.getChildAt(i);
ImageView imgEdit = (ImageView) view.findViewById(R.id.img_edit);
if (imgEdit != null) {
imgEdit.setVisibility(View.VISIBLE);
}
}
}
/**
* 完成编辑模式
*
* @param parent
*/
private void cancelEditMode(RecyclerView parent) {
isEditMode = false;
int visibleChildCount = parent.getChildCount();
for (int i = 0; i < visibleChildCount; i++) {
View view = parent.getChildAt(i);
ImageView imgEdit = (ImageView) view.findViewById(R.id.img_edit);
if (imgEdit != null) {
imgEdit.setVisibility(View.INVISIBLE);
}
}
}
/**
* 获取位移动画
*/
private TranslateAnimation getTranslateAnimator(float targetX, float targetY) {
TranslateAnimation translateAnimation = new TranslateAnimation(
Animation.RELATIVE_TO_SELF, 0f,
Animation.ABSOLUTE, targetX,
Animation.RELATIVE_TO_SELF, 0f,
Animation.ABSOLUTE, targetY);
// RecyclerView默认移动动画250ms 这里设置360ms 是为了防止在位移动画结束后 remove(view)过早 导致闪烁
translateAnimation.setDuration(ANIM_TIME);
translateAnimation.setFillAfter(true);
return translateAnimation;
}
public interface OnMyChannelItemClickListener {
void onItemClick(View v, int position);
}
public interface OnCompleteListener {
void onComplete(List list);
}
public void setOnMyChannelItemClickListener(OnMyChannelItemClickListener listener) {
this.mChannelItemClickListener = listener;
}
public void setmCompleteListener(OnCompleteListener mCompleteListener) {
this.mCompleteListener = mCompleteListener;
}
/**
* 我的频道
*/
class MyViewHolder extends RecyclerView.ViewHolder implements OnDragVHListener {
@BindView(R.id.tv)
TextView textView;
@BindView(R.id.img_edit)
ImageView imgEdit;
public MyViewHolder(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
}
/**
* item 被选中时
*/
@Override
public void onItemSelected() {
textView.setBackgroundResource(R.drawable.bg_channel_p);
}
/**
* item 取消选中时
*/
@Override
public void onItemFinish() {
textView.setBackgroundResource(R.drawable.bg_channel);
}
}
/**
* 其他频道
*/
class OtherViewHolder extends RecyclerView.ViewHolder {
@BindView(R.id.tv)
TextView textView;
public OtherViewHolder(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
}
}
/**
* 我的频道 标题部分
*/
class MyChannelHeaderViewHolder extends RecyclerView.ViewHolder {
@BindView(R.id.tv_btn_edit)
TextView tvBtnEdit;
@BindView(R.id.tv_description)
TextView tvDescription;
public MyChannelHeaderViewHolder(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
}
}
/**
* 我的频道条目的点击事件
*
* @param myHolder
* @param parent
* @param v
*/
private void clickMyChannelItem(MyViewHolder myHolder, ViewGroup parent, View v) {
int position = myHolder.getAdapterPosition();
if (isEditMode) {
if (position != 1) {
RecyclerView recyclerView = ((RecyclerView) parent);
View targetView = recyclerView.getLayoutManager().findViewByPosition(mMyChannelItems.size() + COUNT_PRE_OTHER_HEADER);
View currentView = recyclerView.getLayoutManager().findViewByPosition(position);
// 如果targetView不在屏幕内,则indexOfChild为-1
// 此时不需要添加动画,因为此时notifyItemMoved自带一个向目标移动的动画
// 如果在屏幕内,则添加一个位移动画
if (recyclerView.indexOfChild(targetView) >= 0) {
Logger.e("从我的频道到其他频道，用到了自定义动画");
int targetX, targetY;
RecyclerView.LayoutManager manager = recyclerView.getLayoutManager();
int spanCount = ((GridLayoutManager) manager).getSpanCount();
// 移动后 高度将变化 (我的频道Grid 最后一个item在新的一行第一个)
if ((mMyChannelItems.size() - COUNT_PRE_MY_HEADER) % spanCount == 0) {
View preTargetView = recyclerView.getLayoutManager().findViewByPosition(mMyChannelItems.size() + COUNT_PRE_OTHER_HEADER - 1);
targetX = preTargetView.getLeft();
targetY = preTargetView.getTop();
} else {
targetX = targetView.getLeft();
targetY = targetView.getTop();
}
moveMyToOther(myHolder);
startAnimation(recyclerView, currentView, targetX, targetY);
} else {
moveMyToOther(myHolder);
}
}
} else {
if (mChannelItemClickListener != null) {
mChannelItemClickListener.onItemClick(v, position - COUNT_PRE_MY_HEADER);
}
}
}
public List getmOtherChannelItems() {
return mOtherChannelItems;
}
}
adpater的代码可能比较多，但逻辑也非常简单，从代码中我们可以发现实现了MyViewHolder.java实现了OnDragVHListener接口，ClassifyAdapter实现了OnItemMoveListener接口，这些调用逻辑清楚了，其实我们就比较好理解了。
完整demo地址