Java tutorial
package com.mlxing.mlguide.adapter.base.recyclerview;/* * Copyright (C) 2014 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * limitations under the License. */ import android.content.Context; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Rect; import android.graphics.drawable.Drawable; import android.support.v4.content.ContextCompat; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.view.View; /** * This class is from the v7 samples of the Android SDK. It's not by me! * <p/> * See the license above for details. */ public class DividerItemDecoration extends RecyclerView.ItemDecoration { private static final int[] ATTRS = new int[] { android.R.attr.listDivider }; public static final int HORIZONTAL_LIST = LinearLayoutManager.HORIZONTAL; public static final int VERTICAL_LIST = LinearLayoutManager.VERTICAL; private Drawable mDivider; private int mOrientation; private Paint mPaint; private int mDividerHeight = 2;//1px public DividerItemDecoration(Context context, int orientation) { final TypedArray a = context.obtainStyledAttributes(ATTRS); mDivider = a.getDrawable(0); a.recycle(); setOrientation(orientation); } /** * * * @param context * @param orientation ? * @param drawableId */ public DividerItemDecoration(Context context, int orientation, int drawableId) { this(context, orientation); mDivider = ContextCompat.getDrawable(context, drawableId); mDividerHeight = mDivider.getIntrinsicHeight(); } /** * * * @param context * @param orientation ? * @param dividerHeight * @param dividerColor */ public DividerItemDecoration(Context context, int orientation, int dividerHeight, int dividerColor) { this(context, orientation); mDividerHeight = dividerHeight; mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); mPaint.setColor(dividerColor); mPaint.setStyle(Paint.Style.FILL); } public void setOrientation(int orientation) { if (orientation != HORIZONTAL_LIST && orientation != VERTICAL_LIST) { throw new IllegalArgumentException("invalid orientation"); } mOrientation = orientation; } @Override public void onDraw(Canvas c, RecyclerView parent) { if (mOrientation == VERTICAL_LIST) { drawVertical(c, parent); } else { drawHorizontal(c, parent); } } public void drawVertical(Canvas c, RecyclerView parent) { final int left = parent.getPaddingLeft(); final int right = parent.getWidth() - parent.getPaddingRight(); final int childCount = parent.getChildCount(); for (int i = 0; i < childCount; i++) { final View child = parent.getChildAt(i); android.support.v7.widget.RecyclerView v = new android.support.v7.widget.RecyclerView( parent.getContext()); final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams(); final int top = child.getBottom() + params.bottomMargin; final int bottom = top + mDividerHeight; if (mDivider != null) { mDivider.setBounds(left, top, right, bottom); mDivider.draw(c); } if (mPaint != null) { c.drawRect(left, top, right, bottom, mPaint); } } } public void drawHorizontal(Canvas c, RecyclerView parent) { final int top = parent.getPaddingTop(); final int bottom = parent.getHeight() - parent.getPaddingBottom(); final int childCount = parent.getChildCount(); for (int i = 0; i < childCount; i++) { final View child = parent.getChildAt(i); final RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams(); final int left = child.getRight() + params.rightMargin; final int right = left + mDividerHeight; if (mDivider != null) { mDivider.setBounds(left, top, right, bottom); mDivider.draw(c); } if (mPaint != null) { c.drawRect(left, top, right, bottom, mPaint); } } } @Override public void getItemOffsets(Rect outRect, int itemPosition, RecyclerView parent) { if (mOrientation == VERTICAL_LIST) { outRect.set(0, 0, 0, mDividerHeight); } else { //mDivider.getIntrinsicWidth() outRect.set(0, 0, mDividerHeight, 0); } } }