package com.tejia.lijin.app.ui.category.utilview;
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import android.content.Context;
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import android.graphics.Canvas;
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import android.graphics.Rect;
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import androidx.recyclerview.widget.GridLayoutManager;
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import androidx.recyclerview.widget.RecyclerView;
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import android.text.TextUtils;
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import android.util.Log;
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import android.util.TypedValue;
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import android.view.LayoutInflater;
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import android.view.View;
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import android.view.ViewGroup;
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import android.widget.TextView;
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import com.tejia.lijin.app.R;
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import com.tejia.lijin.app.entity.SecondCategory;
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import java.util.List;
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/**
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* Created by User on 2017/7/24.
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*/
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public class ItemHeaderDecoration extends RecyclerView.ItemDecoration {
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private Context mContext;
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private List<SecondCategory> mList;
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public static String currentTag = "0";
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private LayoutInflater mLayoutInflater;
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private int mTitleHight = 30;
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private int mTitleTextSize = 16;
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CategorySlideListener slideListener;
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public ItemHeaderDecoration(Context context, List<SecondCategory> dataList) {
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super();
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this.mContext = context;
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this.mList = dataList;
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mTitleHight = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 30, context.getResources().getDisplayMetrics());
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// mTitleTextSize = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 20, context.getResources().getDisplayMetrics());
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this.mLayoutInflater = LayoutInflater.from(mContext);
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}
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public static void setCurrentTag(String tag) {
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ItemHeaderDecoration.currentTag = tag;
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}
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@Override
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public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
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super.onDraw(c, parent, state);
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}
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@Override
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public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
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super.getItemOffsets(outRect, view, parent, state);
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}
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@Override
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public void onDrawOver(Canvas c, RecyclerView parent, RecyclerView.State state) {
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//获取到视图中第一个可见的item的position
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int position = ((GridLayoutManager) parent.getLayoutManager()).findFirstVisibleItemPosition();
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// int position = ((GridLayoutManager) parent.getLayoutManager()).findFirstCompletelyVisibleItemPosition();
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String tag = mList.get(position).getTag();
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View child = parent.findViewHolderForLayoutPosition(position).itemView;
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boolean flag = false;
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if ((position + 3) < mList.size()) {
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String suspensionTag1 = mList.get(position + 1).getTag();
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String suspensionTag2 = mList.get(position + 2).getTag();
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String suspensionTag3 = mList.get(position + 3).getTag();
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if (null != tag && (!tag.equals(suspensionTag1) || !tag.equals(suspensionTag2) || !tag.equals(suspensionTag3))) {
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Log.d("ZHG-TEST", "!!!!!!!!!!!!!child.Height() = " + child.getHeight() + " , child.top = " + child.getTop() + " , mTitleHight = " + mTitleHight);
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if (child.getHeight() + child.getTop() < mTitleHight) {
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c.save();
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flag = true;
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c.translate(0, child.getHeight() + child.getTop() - mTitleHight);
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}
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}
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}
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View topTitleView = mLayoutInflater.inflate(R.layout.detail_title, parent, false);
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TextView textView = topTitleView.findViewById(R.id.title_textview);
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textView.setTextSize(mTitleTextSize);
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textView.setText(tag);
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int toDrawWidthSpec;//用于测量的widthMeasureSpec
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int toDrawHeightSpec;//用于测量的heightMeasureSpec
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RecyclerView.LayoutParams lp = (RecyclerView.LayoutParams) topTitleView.getLayoutParams();
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if (lp == null) {
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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
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topTitleView.setLayoutParams(lp);
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}
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topTitleView.setLayoutParams(lp);
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if (lp.width == ViewGroup.LayoutParams.MATCH_PARENT) {
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//如果是MATCH_PARENT，则用父控件能分配的最大宽度和EXACTLY构建MeasureSpec。
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toDrawWidthSpec = View.MeasureSpec.makeMeasureSpec(parent.getWidth() - parent.getPaddingLeft() - parent.getPaddingRight(), View.MeasureSpec.EXACTLY);
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} else if (lp.width == ViewGroup.LayoutParams.WRAP_CONTENT) {
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//如果是WRAP_CONTENT，则用父控件能分配的最大宽度和AT_MOST构建MeasureSpec。
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toDrawWidthSpec = View.MeasureSpec.makeMeasureSpec(parent.getWidth() - parent.getPaddingLeft() - parent.getPaddingRight(), View.MeasureSpec.AT_MOST);
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} else {
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//否则则是具体的宽度数值，则用这个宽度和EXACTLY构建MeasureSpec。
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toDrawWidthSpec = View.MeasureSpec.makeMeasureSpec(lp.width, View.MeasureSpec.EXACTLY);
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}
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//高度同理
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if (lp.height == ViewGroup.LayoutParams.MATCH_PARENT) {
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toDrawHeightSpec = View.MeasureSpec.makeMeasureSpec(parent.getHeight() - parent.getPaddingTop() - parent.getPaddingBottom(), View.MeasureSpec.EXACTLY);
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} else if (lp.height == ViewGroup.LayoutParams.WRAP_CONTENT) {
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toDrawHeightSpec = View.MeasureSpec.makeMeasureSpec(parent.getHeight() - parent.getPaddingTop() - parent.getPaddingBottom(), View.MeasureSpec.AT_MOST);
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} else {
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toDrawHeightSpec = View.MeasureSpec.makeMeasureSpec(mTitleHight, View.MeasureSpec.EXACTLY);
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}
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//依次调用 measure,layout,draw方法，将复杂头部显示在屏幕上。
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topTitleView.measure(toDrawWidthSpec, toDrawHeightSpec);
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topTitleView.layout(parent.getPaddingLeft(), parent.getPaddingTop(), parent.getPaddingLeft() + topTitleView.getMeasuredWidth(), parent.getPaddingTop() + topTitleView.getMeasuredHeight());
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topTitleView.draw(c);//Canvas默认在视图顶部，无需平移，直接绘制
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if (flag)
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c.restore();//恢复画布到之前保存的状态
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if (!TextUtils.equals(tag, currentTag)) {
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currentTag = tag;
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}
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}
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}
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