package com.allen.view;

import static android.view.View.MeasureSpec.EXACTLY;

import static android.view.View.MeasureSpec.makeMeasureSpec;

import android.content.Context;

import android.content.res.TypedArray;

import android.util.AttributeSet;

import android.view.View;

import android.view.ViewGroup;

import com.allen.mygridlayout.R;

/**

 * @author allen

 * @email jaylong1302@163.com

 * @date 2013-11-26 下午1:19:35

 * @company 富媒科技

 * @version 1.0

 * @description 格子布局(类似4.0中的gridlayout)

 */

public class MyGridLayout extends ViewGroup {

    private final String TAG = "MyGridLayout";

    int margin = 2;// 每个格子的水平和垂直间隔

    int colums = 2;

    private int mMaxChildWidth = 0;

    private int mMaxChildHeight = 0;

    int count = 0;

    GridAdatper adapter;

    public MyGridLayout(Context context, AttributeSet attrs, int defStyle) {

        super(context, attrs, defStyle);

        if (attrs != null) {

            TypedArray a = getContext().obtainStyledAttributes(attrs,

                    R.styleable.MyGridLayout);

            colums = a.getInteger(R.styleable.MyGridLayout_numColumns, 2);

            margin = (int) a.getInteger(R.styleable.MyGridLayout_itemMargin, 2);

        }

    }

    public MyGridLayout(Context context, AttributeSet attrs) {

        this(context, attrs, 0);

    }

    public MyGridLayout(Context context) {

        this(context, null);

    }

    @Override

    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

        // TODO Auto-generated method stub

        mMaxChildWidth = 0;

        mMaxChildHeight = 0;

        int modeW = 0, modeH = 0;

        if (MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED)

            modeW = MeasureSpec.UNSPECIFIED;

        if (MeasureSpec.getMode(heightMeasureSpec) != MeasureSpec.UNSPECIFIED)

            modeH = MeasureSpec.UNSPECIFIED;

        final int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(

                MeasureSpec.getSize(widthMeasureSpec), modeW);

        final int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(

                MeasureSpec.getSize(heightMeasureSpec), modeH);

        count = getChildCount();

        if (count == 0) {

            super.onMeasure(childWidthMeasureSpec, childHeightMeasureSpec);

            return;

        }

        for (int i = 0; i < count; i++) {

            final View child = getChildAt(i);

            if (child.getVisibility() == GONE) {

                continue;

            }

            child.measure(childWidthMeasureSpec, childHeightMeasureSpec);

            mMaxChildWidth = Math.max(mMaxChildWidth, child.getMeasuredWidth());

            mMaxChildHeight = Math.max(mMaxChildHeight,

                    child.getMeasuredHeight());

        }

        setMeasuredDimension(resolveSize(mMaxChildWidth, widthMeasureSpec),

                resolveSize(mMaxChildHeight, heightMeasureSpec));

    }

    @Override

    protected void onLayout(boolean changed, int l, int t, int r, int b) {

        // TODO Auto-generated method stub

        int height = b - t;// 布局区域高度

        int width = r - l;// 布局区域宽度

        int rows = count % colums == 0 ? count / colums : count / colums + 1;// 行数

        if (count == 0)

            return;

        int gridW = (width - margin * (colums - 1)) / colums;// 格子宽度

        int gridH = (height - margin * rows) / rows;// 格子高度

        int left = 0;

        int top = margin;

        for (int i = 0; i < rows; i++) {// 遍历行

            for (int j = 0; j < colums; j++) {// 遍历每一行的元素

                View child = this.getChildAt(i * colums + j);

                if (child == null)

                    return;

                left = j * gridW + j * margin;

                // 如果当前布局宽度和测量宽度不一样，就直接用当前布局的宽度重新测量

                if (gridW != child.getMeasuredWidth()

                        || gridH != child.getMeasuredHeight()) {

                    child.measure(makeMeasureSpec(gridW, EXACTLY),

                            makeMeasureSpec(gridH, EXACTLY));

                }

                child.layout(left, top, left + gridW, top + gridH);

                // System.out

                // .println("--top--" + top + ",bottom=" + (top + gridH));

            }

            top += gridH + margin;

        }

    }

    public interface GridAdatper {

        View getView(int index);

        int getCount();

    }

    /** 设置适配器 */

    public void setGridAdapter(GridAdatper adapter) {

        this.adapter = adapter;

        // 动态添加视图

        int size = adapter.getCount();

        for (int i = 0; i < size; i++) {

            addView(adapter.getView(i));

        }

    }

    public interface OnItemClickListener {

        void onItemClick(View v, int index);

    }

    public void setOnItemClickListener(final OnItemClickListener click) {

        if (this.adapter == null)

            return;

        for (int i = 0; i < adapter.getCount(); i++) {

            final int index = i;

            View view = getChildAt(i);

            view.setOnClickListener(new View.OnClickListener() {

                @Override

                public void onClick(View v) {

                    // TODO Auto-generated method stub

                    click.onItemClick(v, index);

                }

            });

        }

    }

}