完全自定义RecyclerView下拉刷新上拉加载

自从谷歌推出SwipeRefreshLayout之后越来越多的博客都是使用SwipeRefreshLayout来完成下拉刷新,但是往往产品经理根本不会使用谷歌的样式.每个公司都有一套自己的下拉样式这个时候就需要我们完全自定义RecyclerView的下拉刷新,基本查阅了网上所有的下拉刷新,但是效果都不怎么样.个人感觉我写的这个下拉刷新效果方面绝对的66666,欢迎可以提出一些改进意见:

废话不多说 先上效果图:

RecyclerView 出现以后，Android 里的下拉刷新和加载更多实现起来就非常容易了。当然，现成的库也有很多，只是总会有不一样的需求，而且我们往往只需要最基本的下拉刷新和加载更多功能，而不需要其他多余的功能。我只需要一个最纯粹的下拉刷新和加载更多。所以，自己动手显然是最好的结果了，也算是个小练习

在介绍代码之前我们先来讲一下实现原理:

首先,我们先通过重写RecyclerView的Adapter类装饰器为起实现addHeaderView,addFootView方法来添加头部与尾部。头部的实现是通过动态的修改的头部控件的高度,尾部的实现是通过动态修改它的BottomMargin,因为尾部的是默认显示的,使用Margin好实现,如果想实现下拉刷新和上拉加载功能，那么就必须有拉伸效果，所以就像上面的那样，Header是通过设置height,Footer是通过设置BottomMargin来模拟拉伸效果。那么回弹效果呢？仅仅通过设置高度或者是间隔是达不到模拟回弹效果的，因此，就需要用Scroller来实现模拟回弹效果。

本项目我把它分为主要的五部分HeaderAndFooterWrapper,PullRefreshRecyclerView,RecyclerViewFooter,RecyclerViewHeader,MessageRelativeLayout

下面我们分开来介绍。

HeaderAndFooterWrapper

这个类主要实现了RecyclerView的addHeaderView,addFootView方法,详细资料看参考弘洋大神的Android 优雅的为RecyclerView添加HeaderView和FooterView

以下是详细代码:

1. /**

2. * Created by on 2017/7/5.

3. * 公司:北京华星成汇文化发展有限公司

4. * 描述:

5. */

6.  

7. public class HeaderAndFooterWrapper extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

8. private static final int BASE_ITEM_TYPE_HEADER = 100000;

9. private static final int BASE_ITEM_TYPE_FOOTER = 200000;

10. //头集合 尾结合

11. private SparseArrayCompat<View> mHeaderViews = new SparseArrayCompat<>();

12. private SparseArrayCompat<View> mFootViews = new SparseArrayCompat<>();

13.  

14. private RecyclerView.Adapter mInnerAdapter;

15.  

16. /**

17. * 把传进来的adapter赋值给成员变量

18. *

19. * @param adapter

20. */

21. public HeaderAndFooterWrapper(RecyclerView.Adapter adapter) {

22. mInnerAdapter = adapter;

23. }

24.  

25. private boolean isHeaderViewPos(int position) {

26. return position < getHeadersCount();

27. }

28.  

29. private boolean isFooterViewPos(int position) {

30. return position >= getHeadersCount() + getRealItemCount();

31. }

32.  

33. /**

34. * 添加头部方法

35. *

36. * @param view

37. */

38. public void addHeaderView(View view) {

39. mHeaderViews.put(mHeaderViews.size() + BASE_ITEM_TYPE_HEADER, view);

40. }

41.  

42. /**

43. * 添加尾部方法

44. *

45. * @param view

46. */

47. public void addFootView(View view) {

48. mFootViews.put(mFootViews.size() + BASE_ITEM_TYPE_FOOTER, view);

49. }

50.  

51. /**

52. * 获取头部集合的大小

53. *

54. * @return

55. */

56. public int getHeadersCount() {

57. return mHeaderViews.size();

58. }

59.  

60. /**

61. * 获取尾部集合的大小

62. *

63. * @return

64. */

65. public int getFootersCount() {

66. return mFootViews.size();

67. }

68.  

69. /**

70. * 获取adapter的大小

71. *

72. * @return

73. */

74. private int getRealItemCount() {

75. return mInnerAdapter.getItemCount();

76. }

77.  

78. @Override

79. public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {

80. if (mHeaderViews.get(viewType) != null) {

81.  

82. // ViewHolder holder = ViewHolder.createViewHolder(parent.getContext(), mHeaderViews.get(viewType));

83. // return holder;

84. return new HeaderViewHolder(mHeaderViews.get(viewType));

85.  

86. } else if (mFootViews.get(viewType) != null) {

87. // ViewHolder holder = ViewHolder.createViewHolder(parent.getContext(), mFootViews.get(viewType));

88. // return holder;

89. return new FootViewHolder(mFootViews.get(viewType));

90. }

91. return mInnerAdapter.onCreateViewHolder(parent, viewType);

92. }

93.  

94. @Override

95. public int getItemViewType(int position) {

96.  

97. if (isHeaderViewPos(position)) {

98. return mHeaderViews.keyAt(position);

99. } else if (isFooterViewPos(position)) {

100. return mFootViews.keyAt(position - getHeadersCount() - getRealItemCount());

101. }

102. return mInnerAdapter.getItemViewType(position - getHeadersCount());

103. }

104.  

105. @Override

106. public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {

107. if (isHeaderViewPos(position)) {

108. return;

109. }

110. if (isFooterViewPos(position)) {

111. return;

112. }

113. mInnerAdapter.onBindViewHolder(holder, position - getHeadersCount());

114. }

115.  

116. @Override

117. public int getItemCount() {

118. return getHeadersCount() + getFootersCount() + getRealItemCount();

119. }

120.  
121.  

122. @Override

123. public void onAttachedToRecyclerView(RecyclerView recyclerView) {

124. mInnerAdapter.onAttachedToRecyclerView(recyclerView);

125.  

126. /**

127. * 解决网格布局问题

128. */

129. RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();

130. if (layoutManager instanceof GridLayoutManager) {

131. final GridLayoutManager gridLayoutManager = (GridLayoutManager) layoutManager;

132.  

133. gridLayoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {

134. @Override

135. public int getSpanSize(int position) {

136. int viewType = getItemViewType(position);

137. if (mHeaderViews.get(viewType) != null) {

138. return gridLayoutManager.getSpanCount();

139. } else if (mFootViews.get(viewType) != null) {

140. return gridLayoutManager.getSpanCount();

141. } else {

142. return 1;

143. }

144. }

145. });

146. }

147. }

148.  

149. // /**

150. // * 解决 StaggeredGridLayoutManager样式的加头部问题,暂时没用

151. // * @param holder

152. // */

153. // @Override

154. // public void onViewAttachedToWindow(RecyclerView.ViewHolder holder) {

155. // mInnerAdapter.onViewAttachedToWindow(holder);

156. // int position = holder.getLayoutPosition();

157. // if (isHeaderViewPos(position) || isFooterViewPos(position)) {

158. // ViewGroup.LayoutParams lp = holder.itemView.getLayoutParams();

159. //

160. // if (lp != null && lp instanceof StaggeredGridLayoutManager.LayoutParams) {

161. //

162. // StaggeredGridLayoutManager.LayoutParams p = (StaggeredGridLayoutManager.LayoutParams) lp;

163. //

164. // p.setFullSpan(true);

165. // }

166. // }

167. // }

168.  
169.  

170. private class HeaderViewHolder extends RecyclerView.ViewHolder {

171. HeaderViewHolder(View itemView) {

172. super(itemView);

173. }

174. }

175.  

176. private class FootViewHolder extends RecyclerView.ViewHolder {

177. FootViewHolder(View itemView) {

178. super(itemView);

179.  

180. }

181. }

182. }

 

RecyclerViewHeader

RecyclerViewHeader继承自LinearLayout用来实现下拉刷新时的界面展示，可以分为三种状态：正常、准备刷新、正在加载。在添加布局文件的时候，指定高度为0，这是为了隐藏header,setState()是设置header的状态，因为header需要根据不同的状态，完成控件隐藏、显示、改变文字等操作，这个方法主要是在PullRefreshRecyclerView里面调用。除此之外，还有setVisiableHeight()和getVisiableHeight()，这两个方法是为了设置和获取Header中根布局文件的高度属性，从而完成拉伸和收缩的效果

1. /**

2. * Created by 刘龙 on 2017/7/18.

3. * 公司:北京华星成汇文化发展有限公司

4. * 描述:

5. */

6.  

7. public class RecyclerViewHeader extends LinearLayout {

8. /**

9. * 动画执行时间

10. */

11. private final int ROTATE_ANIM_DURATION = 180;

12.  

13. public final static int STATE_NORMAL = 0;

14. public final static int STATE_READY = 1;

15. public final static int STATE_REFRESHING = 2;

16. /**

17. * 当前状态

18. */

19. private int mState = STATE_NORMAL;

20.  

21. //获取到头布局

22. private LinearLayout mContainer;

23. //获取到控件

24. private ImageView mArrowImageView;

25. // private ProgressBar mProgressBar;

26. private TextView mHintTextView;

27. //初始化动画

28. // private RotateAnimation mRotateUpAnim;

29. // private Animation mRotateDownAnim;

30. private TextView mTitleTextView;

31. private RelativeLayout mRealityContent;

32.  
33.  

34. public RecyclerViewHeader(Context context) {

35. this(context, null);

36. }

37.  

38. public RecyclerViewHeader(Context context, @Nullable AttributeSet attrs) {

39. this(context, attrs, 0);

40. }

41.  

42. public RecyclerViewHeader(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {

43. super(context, attrs, defStyleAttr);

44.  

45. init(context);

46. }

47.  

48. private void init(Context context) {

49. // 初始情况，设置下拉刷新view高度为0

50. LayoutParams lp = new LayoutParams(LayoutParams.MATCH_PARENT, 0);

51. //获取下拉布局

52. mContainer = (LinearLayout) LayoutInflater.from(context).inflate(R.layout.pullrefrefh_recyclerview_header, (ViewGroup) getParent(), true);

53. //添加到改容器

54. addView(mContainer, lp);

55. //显示位置下面

56. setGravity(Gravity.BOTTOM | Gravity.CENTER_HORIZONTAL);

57. //初始化控件

58. mRealityContent = (RelativeLayout) mContainer.findViewById(R.id.pullRefresh_reality_content);

59. mArrowImageView = (ImageView) mContainer.findViewById(R.id.pullRefresh_arrow);

60. mHintTextView = (TextView) mContainer.findViewById(R.id.pullRefresh_text);

61. // mProgressBar = (ProgressBar) findViewById(R.id.pullRefresh_progressbar);

62. mTitleTextView = (TextView) mContainer.findViewById(R.id.pullRefresh_title);

63.  

64. //初始化动画

65. // mRotateUpAnim = new RotateAnimation(0.0f, -180.0f,

66. // Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,

67. // 0.5f);

68. // mRotateUpAnim.setDuration(ROTATE_ANIM_DURATION);

69. // mRotateUpAnim.setFillAfter(true);

70. // mRotateDownAnim = new RotateAnimation(-180.0f, 0.0f,

71. // Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF,

72. // 0.5f);

73. // mRotateDownAnim.setDuration(ROTATE_ANIM_DURATION);

74. // mRotateDownAnim.setFillAfter(true);

75. }

76.  

77. public void setState(int state) {

78. //如果状态相同 直接返回

79. if (mState == state) return;

80.  

81. //如果传进来的是刷新状态

82. if (state == STATE_REFRESHING) { // 正在加载显示圆圈进度

83. // mArrowImageView.clearAnimation();

84. // mArrowImageView.setVisibility(View.INVISIBLE);

85. // mProgressBar.setVisibility(View.VISIBLE);

86. } else { // 显示箭头图片

87. // mArrowImageView.setVisibility(View.VISIBLE);

88. // mProgressBar.setVisibility(View.INVISIBLE);

89. }

90.  

91. switch (state) {

92. case STATE_NORMAL://正常状态

93. if (mState == STATE_READY) {

94. // mArrowImageView.startAnimation(mRotateDownAnim);

95. }

96. if (mState == STATE_REFRESHING) {

97. // mArrowImageView.clearAnimation();

98. }

99. mHintTextView.setText("下拉刷新");

100. break;

101. case STATE_READY://可以刷新状态

102. if (mState != STATE_READY) {

103. // mArrowImageView.clearAnimation();

104. // mArrowImageView.startAnimation(mRotateUpAnim);

105. mHintTextView.setText("松开刷新数据");

106. }

107. break;

108. case STATE_REFRESHING://刷新状态

109. mHintTextView.setText("正在加载...");

110. break;

111. default:

112. }

113.  

114. mState = state;

115.  

116. }

117.  

118. /**

119. * 设置显示的图片

120. *

121. * @param imagePath

122. */

123. public void setPullImage(String imagePath) {

124. Drawable fromPath = Drawable.createFromPath(imagePath);

125. Bitmap bitmap = BitmapFactory.decodeFile(imagePath);

126. // mArrowImageView.setBackground(fromPath);

127. mArrowImageView.setImageBitmap(bitmap);

128. }

129.  

130. /**

131. * 设置显示的文字

132. *

133. * @param text

134. */

135. public void setPullContent(String text) {

136. mTitleTextView.setText(text);

137.  

138. }

139.  

140. /**

141. * 获取本身实际的高度

142. */

143. public int getRealityHeight() {

144. return mRealityContent.getHeight();

145. }

146.  
147.  

148. /**

149. * 设置隐藏高度

150. *

151. * @param height

152. */

153. public void setVisibleHeight(int height) {

154. if (height < 0) {

155. height = 0;

156. }

157.  

158. LayoutParams lp = (LayoutParams) mContainer.getLayoutParams();

159. lp.height = height;

160. mContainer.setLayoutParams(lp);

161. }

162.  

163. /**

164. * 获取隐藏的高度

165. *

166. * @return

167. */

168. public int getVisibleHeight() {

169. return mContainer.getLayoutParams().height;

170. }

171. }

 

说完了Header，我们再看看Footer。Footer是为了完成加载更多功能时候的界面展示，基本思路和Header是一样的，不过Footer的拉伸和显示效果不是通过高度来模拟的，而是通过设置BottomMargin来完成的。

1. /**

2. * Created by 刘龙 on 2017/8/9.

3. * 公司:北京华星成汇文化发展有限公司

4. * 描述:

5. */

6.  

7. public class RecyclerViewFooter extends LinearLayout {

8. public final static int STATE_NORMAL = 0;

9. public final static int STATE_READY = 1;

10. public final static int STATE_LOADING = 2;

11.  

12. private Context context;

13. private View contentView;

14. private View progressBar;

15. private TextView hintView;

16.  
17.  

18. public RecyclerViewFooter(Context context) {

19. this(context, null);

20. }

21.  

22. public RecyclerViewFooter(Context context, @Nullable AttributeSet attrs) {

23. this(context, attrs, 0);

24. }

25.  

26. public RecyclerViewFooter(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {

27. super(context, attrs, defStyleAttr);

28. this.context = context;

29. initView();

30.  

31. }

32.  

33. private void initView() {

34. LinearLayout moreView = (LinearLayout) LayoutInflater.from(context).inflate(R.layout.pullrefrefh_recyclerview_footer, null);

35. addView(moreView);

36. moreView.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));

37.  

38. contentView = moreView.findViewById(R.id.pullrefrefh_footer_content);

39. progressBar = moreView.findViewById(R.id.pullrefrefh_footer_ProgressBar);

40. hintView = (TextView) moreView.findViewById(R.id.pullrefrefh_footer_hint_TextView);

41. }

42.  

43. /**

44. * 设置状态

45. *

46. * @param state

47. */

48. public void setState(int state) {

49. hintView.setVisibility(View.INVISIBLE);

50. progressBar.setVisibility(View.INVISIBLE);

51. hintView.setVisibility(View.INVISIBLE);

52. if (state == STATE_READY) {

53. hintView.setVisibility(View.VISIBLE);

54. hintView.setText("松开载入更多");

55. } else if (state == STATE_LOADING) {

56. progressBar.setVisibility(View.VISIBLE);

57. } else {

58. hintView.setVisibility(View.VISIBLE);

59. hintView.setText("查看更多");

60. }

61. }

62.  

63. /**

64. * 设置距离下边的BottomMargin

65. *

66. * @param height

67. */

68. public void setBottomMargin(int height) {

69. if (height < 0) return;

70. LayoutParams lp = (LayoutParams) contentView.getLayoutParams();

71. lp.bottomMargin = height;

72. contentView.setLayoutParams(lp);

73.  

74. }

75.  

76. /**

77. * 获取BottomMargin

78. *

79. * @return

80. */

81. public int getBottomMargin() {

82. LayoutParams lp = (LayoutParams) contentView.getLayoutParams();

83. return lp.bottomMargin;

84. }

85.  
86.  

87. /**

88. * hide footer when disable pull load more

89. */

90. public void hide() {

91. LayoutParams lp = (LayoutParams) contentView.getLayoutParams();

92. lp.height = 0;

93. contentView.setLayoutParams(lp);

94. }

95.  

96. /**

97. * show footer

98. */

99. public void show() {

100. LayoutParams lp = (LayoutParams) contentView.getLayoutParams();

101. lp.height = LayoutParams.WRAP_CONTENT;

102. contentView.setLayoutParams(lp);

103. }

104. }

 

MessageRelativeLayout

该类主要是为了实现在刷新完毕的时候可以显示一个更新了多少条,网络错误等等的提示语:在添加布局文件的时候，指定高度为0，这是为了隐藏提示语,实现思路与头布局类似,如不需要此功能可忽略,不会影响代码的使用

1. /**

2. * Created by on 2017/7/18.

3. * 公司:北京华星成汇文化发展有限公司

4. * 描述:

5. */

6.  

7. public class MessageRelativeLayout extends RelativeLayout {

8.  

9. //显示消息的控件

10. private LinearLayout mHeaderMessageView;

11. private TextView mHeaderMessageText;

12.  
13.  

14. private int mHeaderMessageViewHeight;

15. //滚动类

16. private Scroller mScroller;

17.  

18. public MessageRelativeLayout(Context context) {

19. this(context, null);

20. }

21.  

22. public MessageRelativeLayout(Context context, AttributeSet attrs) {

23. this(context, attrs, 0);

24. }

25.  

26. public MessageRelativeLayout(Context context, AttributeSet attrs, int defStyleAttr) {

27. super(context, attrs, defStyleAttr);

28.  
29.  

30. init(context);

31. }

32.  

33. private void init(Context context) {

34. //滚动类

35. mScroller = new Scroller(context, new DecelerateInterpolator());

36. //初始化一个显示消息的textView

37. mHeaderMessageView = (LinearLayout) LayoutInflater.from(context).inflate(R.layout.pullrefresh_header_message, (ViewGroup) getParent(), false);

38. mHeaderMessageView.setLayoutParams(new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, 0));

39.  

40. mHeaderMessageText = (TextView) mHeaderMessageView.findViewById(R.id.pullRefresh_message);

41.  

42. // 初始化 头部高度

43. mHeaderMessageText.getViewTreeObserver().addOnGlobalLayoutListener(

44. new ViewTreeObserver.OnGlobalLayoutListener() {

45. @Override

46. public void onGlobalLayout() {

47. mHeaderMessageViewHeight = mHeaderMessageText.getHeight();//57

48.  

49. getViewTreeObserver().removeOnGlobalLayoutListener(this);

50. }

51. });

52.  

53. }

54.  

55. @Override

56. protected void onFinishInflate() {

57. super.onFinishInflate();

58. //确保添加到后面

59. addView(mHeaderMessageView, 1);

60. }

61.  

62. public void showMessage() {

63. mScroller.startScroll(0, getHeaderMessageViewHeight(), 0, 0, PullRefreshRecyclerView.SCROLL_DURATION);

64. invalidate();

65. }

66.  

67. public void hideMessage() {

68. mScroller.startScroll(0, getVisibleHeight(), 0, -getVisibleHeight(), PullRefreshRecyclerView.SCROLL_DURATION);

69. invalidate();

70. }

71.  
72.  

73. /**

74. * 设置消息

75. */

76. public void setMessage(String message) {

77. mHeaderMessageText.setText(message);

78.  

79. }

80.  
81.  

82. /**

83. * 获取消息总高度

84. *

85. * @return

86. */

87. public int getHeaderMessageViewHeight() {

88. return mHeaderMessageViewHeight;

89. }

90.  

91. /**

92. * 设置隐藏高度

93. *

94. * @param height

95. */

96. private void setVisibleHeight(int height) {

97. if (height < 0) {

98. height = 0;

99. }

100.  

101. LayoutParams lp = (LayoutParams) mHeaderMessageView.getLayoutParams();

102. lp.height = height;

103. mHeaderMessageView.setLayoutParams(lp);

104. }

105.  

106. /**

107. * 获取隐藏的高度

108. *

109. * @return

110. */

111. public int getVisibleHeight() {

112. return mHeaderMessageView.getLayoutParams().height;

113. }

114. @Override

115. public void computeScroll() {

116. if (mScroller.computeScrollOffset()) {

117.  

118. setVisibleHeight(mScroller.getCurrY());

119.  

120. postInvalidate();

121. }

122. super.computeScroll();

123. }

124. }

 

PullRefreshRecyclerView

在了解了Header,Footer和Message之后，我们就要介绍最核心的PullRefreshRecyclerView的代码实现了。便于观看,本代码有部分删减重构

1. /**

2. * Created by 刘龙 on 2017/7/18.

3. * 公司:北京华星成汇文化发展有限公司

4. * 描述:

5. */

6.  

7. public class PullRefreshRecyclerView extends RecyclerView {

8.  

9. private float mLastY = -1; // save event y

10. /**

11. * 滚动需要的时间

12. */

13. public final static int SCROLL_DURATION = 200;

14.  

15. /**

16. * 提示消息显示时间

17. */

18. public final static int MESSAGE_SHOW_DURATION = 2000;

19. /**

20. * 阻尼效果

21. */

22. private final static float OFFSET_RADIO = 1.5f;

23. /**

24. * 上拉加载的距离,默认50px

25. */

26. private static final int PULL_LOAD_MORE_DELTA = 50;

27.  

28. /**

29. * 是否设置为自动加载更多,目前没实现

30. */

31. private boolean mEnableAutoLoading = false;

32. /**

33. * 是否可以上拉 默认可以

34. */

35. private boolean mEnablePullLoad = true;

36. /**

37. * 是否可以下拉 默认可以

38. */

39. private boolean mEnablePullRefresh = true;

40. /**

41. * 是否正在加载

42. */

43. private boolean mPullLoading = false;

44. /**

45. * 是否正在刷新

46. */

47. private boolean mPullRefreshing = false;

48. /**

49. * 区分上拉和下拉

50. */

51. private int mScrollBack;

52. private final static int SCROLLBACK_HEADER = 0;

53. private final static int SCROLLBACK_FOOTER = 1;

54. //滚动类

55. private Scroller mScroller;

56.  

57. //头布局控件

58. private RecyclerViewHeader mHeaderView;

59. //尾控件

60. private RecyclerViewFooter mFooterView;

61. //消息提示类

62. private MessageRelativeLayout mParent;

63. //adapter的装饰类

64. private HeaderAndFooterWrapper mHeaderAndFooterWrapper;

65.  
66.  

67. public PullRefreshRecyclerView(Context context) {

68. this(context, null);

69. }

70.  

71. public PullRefreshRecyclerView(Context context, @Nullable AttributeSet attrs) {

72. this(context, attrs, 0);

73. }

74.  

75. public PullRefreshRecyclerView(Context context, @Nullable AttributeSet attrs, int defStyle) {

76. super(context, attrs, defStyle);

77. init(context);

78. }

79.  

80. private void init(Context context) {

81. //滚动类

82. mScroller = new Scroller(context, new DecelerateInterpolator());

83. //获取到头布局

84. mHeaderView = new RecyclerViewHeader(context);

85. mHeaderView.setLayoutParams(new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));

86. //获取尾布局

87. mFooterView = new RecyclerViewFooter(context);

88. mFooterView.setLayoutParams(new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));

89.  

90. }

91.  
92.  

93. private Adapter adapter;

94.  

95. @Override

96. public void setAdapter(Adapter adapter) {

97. this.adapter = adapter;

98. mHeaderAndFooterWrapper = new HeaderAndFooterWrapper(adapter);

99.  

100. super.setAdapter(mHeaderAndFooterWrapper);

101.  

102. //添加头,确保是第一个

103. mHeaderAndFooterWrapper.addHeaderView(mHeaderView);

104. //添加尾,确保是第最后一个

105. mHeaderAndFooterWrapper.addFootView(mFooterView);

106. //获取到它的父容器

107. if (getParent() instanceof MessageRelativeLayout) {

108. mParent = (MessageRelativeLayout) getParent();

109. }

110. }

111.  
112.  

113. @Override

114. public boolean onTouchEvent(MotionEvent e) {

115. if (mLastY == -1) {

116. mLastY = e.getRawY();

117. }

118. switch (e.getAction()) {

119. case MotionEvent.ACTION_DOWN:

120. //按下的时候记录值

121. mLastY = e.getRawY();

122. break;

123. case MotionEvent.ACTION_MOVE:

124.  
125.  

126. float moveY = e.getRawY();

127. //手指滑动的差值

128. float distanceY = moveY - mLastY;

129. mLastY = moveY;

130.  

131. //第一个条目完全显示 //头部高度大于0 deltaY大于0 向下移动

132. if ((((LinearLayoutManager) getLayoutManager()).findFirstCompletelyVisibleItemPosition() == 0 || ((LinearLayoutManager) getLayoutManager()).findFirstCompletelyVisibleItemPosition() == 1) && (mHeaderView.getVisibleHeight() > 0 || distanceY > 0)) {

133. // 更新头部高度

134. updateHeaderHeight(distanceY / OFFSET_RADIO);

135. } else if (isSlideToBottom() && (mFooterView.getBottomMargin() > 0 || distanceY < 0)) {

136. Log.e("PullRefreshRecyclerView","-------111------"+distanceY);

137. //已经到达底部,改变状态或者自动加载

138. updateFooterHeight(-distanceY / OFFSET_RADIO);

139. }else if (distanceY > 0){

140. updateFooterHeight(-distanceY / OFFSET_RADIO);

141. }

142.  

143. break;

144. default:

145. mLastY = -1; // 复位

146. if ((((LinearLayoutManager) getLayoutManager()).findFirstCompletelyVisibleItemPosition() == 0 || ((LinearLayoutManager) getLayoutManager()).findFirstCompletelyVisibleItemPosition() == 1)) {

147. // 松手的时候 高度大于 一定值 调用刷新

148. if (mEnablePullRefresh && mHeaderView.getVisibleHeight() > mHeaderView.getRealityHeight()) {

149. //变为刷新状态

150. mPullRefreshing = true;

151. mHeaderView.setState(RecyclerViewHeader.STATE_REFRESHING);

152. //回调事件

153. if (mOnRefreshListener != null) {

154. mOnRefreshListener.onRefresh();

155. }

156. }

157. resetHeaderHeight();

158. } else if (isSlideToBottom()) {

159. // invoke load more.

160. if (mEnablePullLoad && mFooterView.getBottomMargin() > PULL_LOAD_MORE_DELTA && !mPullLoading) {

161. mPullLoading = true;

162. mFooterView.setState(RecyclerViewFooter.STATE_LOADING);

163. if (mOnRefreshListener != null) {

164. mOnRefreshListener.onLoadMore();

165. }

166.  

167. }

168. resetFooterHeight();

169. } else {

170. // resetFooterHeight();

171. resetHeaderHeight();

172. }

173.  

174. break;

175. }

176.  
177.  

178. return super.onTouchEvent(e);

179. }

180.  

181. /**

182. * 更新尾部加载

183. *

184. * @param distance

185. */

186. private void updateFooterHeight(float distance) {

187. int height = mFooterView.getBottomMargin() + (int) distance;

188. Log.e("PullRefreshRecyclerView","-------------"+height);

189. if (mEnablePullLoad && !mPullLoading) {

190. if (height > PULL_LOAD_MORE_DELTA) {

191. //改变状态

192. mFooterView.setState(RecyclerViewFooter.STATE_READY);

193. } else {

194. mFooterView.setState(RecyclerViewFooter.STATE_NORMAL);

195. }

196. }

197. mFooterView.setBottomMargin(height);

198.  

199. }

200.  

201. /**

202. * 更新头部刷新

203. *

204. * @param distance

205. */

206. private void updateHeaderHeight(float distance) {

207.  

208. // 设置头部高度,原先的高度加上

209. mHeaderView.setVisibleHeight((int) distance + mHeaderView.getVisibleHeight());

210. // 未处于刷新状态，更新箭头

211. if (mEnablePullRefresh && !mPullRefreshing) {

212. //下拉高度到达可以刷新的位置

213. if (mHeaderView.getVisibleHeight() > mHeaderView.getRealityHeight()) {

214. mHeaderView.setState(RecyclerViewHeader.STATE_READY);

215. } else {

216. mHeaderView.setState(RecyclerViewHeader.STATE_NORMAL);

217. }

218. }

219. //移动到顶部

220. smoothScrollBy(0, 0);

221. }

222.  

223. /**

224. * 重置头部高度

225. */

226. private void resetHeaderHeight() {

227. int height = mHeaderView.getVisibleHeight();

228. if (height == 0) // 如果=0 是不可见的 直接返回

229. return;

230.  

231. if (mPullRefreshing && height <= mHeaderView.getRealityHeight()) {

232. return;

233. }

234.  

235. int finalHeight = 0;

236.  

237. if (mPullRefreshing && height > mHeaderView.getRealityHeight()) {

238. finalHeight = mHeaderView.getRealityHeight();

239. }

240. if (mParent != null) {

241. if (mHeaderView.getVisibleHeight() == mParent.getHeaderMessageViewHeight()) {

242. finalHeight = mParent.getHeaderMessageViewHeight();

243. }

244. }

245.  

246. mScrollBack = SCROLLBACK_HEADER;//设置标识

247. mScroller.startScroll(0, height, 0, finalHeight - height, SCROLL_DURATION);

248. // 触发计算滚动

249. invalidate();

250. }

251.  

252. /**

253. * 重置尾部高度

254. */

255. private void resetFooterHeight() {

256. int bottomMargin = mFooterView.getBottomMargin();

257. if (bottomMargin > 0) {

258. mScrollBack = SCROLLBACK_FOOTER;//设置标识

259. mScroller.startScroll(0, bottomMargin, 0, -bottomMargin, SCROLL_DURATION);

260. invalidate();

261. }

262. }

263.  

264. /**

265. * 停止刷新

266. */

267. public void stopRefresh() {

268. mScrollBack = SCROLLBACK_HEADER;//设置标识

269. int obligateHeight;

270. if (mParent != null) {

271. obligateHeight = mParent.getHeaderMessageViewHeight();

272. } else {

273. obligateHeight = 0;

274. }

275. int height = mHeaderView.getVisibleHeight();

276. if (mPullRefreshing) {

277. //是否复位

278.  

279. mPullRefreshing = false;

280.  

281. //显示更新了多少条消息

282. if (mParent != null) {

283. mParent.showMessage();

284. }

285. mScroller.startScroll(0, height, 0, obligateHeight - height, SCROLL_DURATION);

286. // 触发计算滚动

287. invalidate();

288.  

289. //延时执行复位移动

290. if (mParent != null) {

291. handler.removeCallbacksAndMessages(null);

292. handler.sendEmptyMessageDelayed(1, MESSAGE_SHOW_DURATION);

293. }

294. }

295.  

296. }

297.  

298. /**

299. * 停止加载

300. */

301. public void stopLoadMore() {

302. if (mPullLoading) {

303. mPullLoading = false;

304. mFooterView.setState(RecyclerViewFooter.STATE_NORMAL);

305. }

306. }

307.  

308. /**

309. * 消息

310. */

311. private Handler handler = new Handler() {

312. @Override

313. public void handleMessage(Message msg) {

314. super.handleMessage(msg);

315. if (mHeaderView.getVisibleHeight() == mParent.getHeaderMessageViewHeight()) {

316. // resetHeaderHeight();

317. mScroller.startScroll(0, mHeaderView.getVisibleHeight(), 0, -mHeaderView.getVisibleHeight(), SCROLL_DURATION);

318. postInvalidate();

319. }

320.  

321. mParent.hideMessage();

322. }

323. };

324.  

325. @Override

326. public void computeScroll() {

327. if (mScroller.computeScrollOffset()) {

328. if (mScrollBack == SCROLLBACK_HEADER) {

329. mHeaderView.setVisibleHeight(mScroller.getCurrY());

330. } else {

331. mFooterView.setBottomMargin(mScroller.getCurrY());

332. }

333. postInvalidate();

334. }

335. super.computeScroll();

336. }

337.  

338. private OnRefreshListener mOnRefreshListener;

339.  

340. public void setOnRefreshListener(OnRefreshListener onRefreshListener) {

341. mOnRefreshListener = onRefreshListener;

342. }

343.  

344. /**

345. * 刷新接口,

346. */

347. public interface OnRefreshListener {

348. void onRefresh();

349.  

350. void onLoadMore();

351. }

352.  

353. /**

354. * 判断是否到底

355. *

356. * @return

357. */

358. private boolean isSlideToBottom() {

359. return computeVerticalScrollExtent() + computeVerticalScrollOffset() >= computeVerticalScrollRange();

360. }

361. }