Android之基于RecycleVew的相册选择器

本文主要记录一个Android自定义的相册

相册可以实现选择图片，视频，gif(或其他任何格式文件)

源码：https://github.com/CL-window/my_photo_view

看看效果

其中RecycleView的分割线修改了一下，基本上可以实现万能分割线类了

package com.example.photoview;

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.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.StaggeredGridLayoutManager;
import android.view.View;

/**
 * 
Description: 分割线  (近乎万能)
 * Created by slack on 2016/7/21 13:56 .
 */
public class DividerGridItemDecoration extends RecyclerView.ItemDecoration {

    private static final int[] ATTRS = new int[]{android.R.attr.listDivider};
    private Drawable mDivider;
    private int type = 0; // 分割线种类  0：水平（默认）   1：垂直   2 ：网格
    private int mDividerHeight = 2;//分割线高度，默认为1px
    private Paint mPaint;

    /**
     * 默认分割线：高度为2px，颜色为灰色
     * @param context
     */
    public DividerGridItemDecoration(Context context) {
        final TypedArray a = context.obtainStyledAttributes(ATTRS);
        mDivider = a.getDrawable(0);
        mDividerHeight = mDivider.getIntrinsicHeight();
        a.recycle();
    }

    /**
     * @param type  分割线种类  0：水平（默认）   1：垂直   2 ：网格
     */
    public DividerGridItemDecoration(Context context, int type) {
        this.type = type;
        final TypedArray a = context.obtainStyledAttributes(ATTRS);
        mDivider = a.getDrawable(0);
        mDividerHeight = mDivider.getIntrinsicHeight();
        a.recycle();
    }

    /**
     * @param drawableId  分割线图片(自定义drawable)
     */
    public DividerGridItemDecoration(Context context, int type,int drawableId) {
        this.type = type;
        mDivider =  ContextCompat.getDrawable(context, drawableId);
        mDividerHeight = mDivider.getIntrinsicHeight();
    }

    /**
     * @param dividerHeight  分割线高度
     * @param dividerColor  分割线颜色
     */
    public DividerGridItemDecoration(Context context, int type,int dividerHeight, int dividerColor) {
        this.type = type;
        mDividerHeight = dividerHeight;
        mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaint.setColor(dividerColor);
        mPaint.setStyle(Paint.Style.FILL);

    }


    //绘制分割线
    @Override
    public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {

        if (type == 0) {
            drawHorizontal(c, parent);
        } else if (type == 1) {
            drawVertical(c, parent);
        }else{
            drawVertical(c, parent);
            drawHorizontal(c, parent);
        }

    }

    private int getSpanCount(RecyclerView parent) {
        // 列数
        int spanCount = -1;
        RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();
        if (layoutManager instanceof GridLayoutManager) {

            spanCount = ((GridLayoutManager) layoutManager).getSpanCount();
        } else if (layoutManager instanceof StaggeredGridLayoutManager) {
            spanCount = ((StaggeredGridLayoutManager) layoutManager)
                    .getSpanCount();
        }
        return spanCount;
    }

    //绘制横向 item 分割线
    public void drawHorizontal(Canvas canvas, RecyclerView parent) {
        int childCount = parent.getChildCount();
        final int left = parent.getPaddingLeft();
        final int right = parent.getMeasuredWidth() - parent.getPaddingRight();
        for (int i = 0; i < childCount; i++) {
            final View child = parent.getChildAt(i);
            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(canvas);
            }
            if (mPaint != null) {
                canvas.drawRect(left, top, right, bottom, mPaint);
            }
        }
    }

    //绘制纵向 item 分割线
    public void drawVertical(Canvas canvas, RecyclerView parent) {
        final int top = parent.getPaddingTop();
        final int bottom = parent.getMeasuredHeight() - 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(canvas);
            }
            if (mPaint != null) {
                canvas.drawRect(left, top, right, bottom, mPaint);
            }
        }
    }

    private boolean isLastColum(RecyclerView parent, int pos, int spanCount,
                                int childCount) {
        RecyclerView.LayoutManager layoutManager = parent.getLayoutManager();