package com.example.canvasdemo;

import android.annotation.SuppressLint;

import android.content.Context;

import android.graphics.Canvas;

import android.graphics.Color;

import android.graphics.Paint;

import android.graphics.Paint.FontMetrics;

import android.graphics.Rect;

import android.util.AttributeSet;

import android.util.Log;

import android.view.View;

import android.view.animation.Animation;

import android.view.animation.Transformation;

public class ChartView extends View{

	@SuppressLint("NewApi")

	public ChartView(Context context, AttributeSet attrs, int defStyleAttr,

			int defStyleRes) {

		super(context, attrs, defStyleAttr, defStyleRes);

		initData();

	}

	public ChartView(Context context, AttributeSet attrs, int defStyleAttr) {

		this(context, attrs, defStyleAttr, 0);

	}

	public ChartView(Context context, AttributeSet attrs) {

		this(context, attrs, 0);

	}

	public ChartView(Context context) {

		this(context, null);

	}

	public void initData(){

		mPaints = new Paint[mChartNum];

		//--初始化需要的画笔

		for (int i = 0; i < mPaints.length; i++) {

			mPaints[i] = new Paint();

			mPaints[i].setAntiAlias(true);

			mPaints[i].setDither(true);

			mPaints[i].setStyle(Paint.Style.FILL);

			mPaints[i].setColor(0x880FF000 + i * 0x019e8860);

			mPaints[i].setTextSize(30);

		}

		initAnim();

	}

	/**

	 * 初始化自定义动画

	 */

	private void initAnim(){

		anim = new ChartAnim();

		anim.setDuration(2000);

	}

	/**

	 * 直方图的数目

	 */

	private int mChartNum = 8;

	private Paint[] mPaints;

	/**

	 * 直方图的宽度

	 */

	private int mChartW = 80;

	//--间隔

	private int mInterval = 20;

	@SuppressLint("DrawAllocation")

	@Override

	protected void onDraw(Canvas canvas) {

		super.onDraw(canvas);

		//--绘制背景色

		canvas.drawColor(Color.TRANSPARENT);

		canvas.save();

		canvas.translate(100, 0);

		//--绘制直方图

		for (int i = 0; i < mPaints.length; i++) {

			canvas.drawRect(new Rect(mChartW*i + mInterval*(i+1),(int)(mH/2 - mmLs[i] * percent),mChartW*(i+1) + mInterval*i,mH/2), mPaints[i]);

		}

		//--绘制文本

		for(int i = 0; i < mmLs.length; i ++){

			int textw = (int) mPaints[i].measureText(mmLs[i]+"");

			FontMetrics mfontm = mPaints[i].getFontMetrics();

			int texth = (int) (mfontm.descent - mfontm.ascent);

			int textT = (mChartW*(i+1) + mInterval*i) - (mChartW*i + mInterval*(i+1));

			int temp = (textT - textw)/2;

			canvas.drawText(mmLs[i]+"",temp + mChartW*i + mInterval*(i+1), mH/2 + texth + mInterval, mPaints[i]);

		}

		//--底部分割线的绘制

		Paint mPaint = new Paint();

		mPaint.setDither(true);

		mPaint.setAntiAlias(true);

		mPaint.setStrokeWidth(3);

//		int rNum = (int) (Math.random()*mmLs.length);

		mPaint.setColor(0x880FF000 + 2*0x019e8860);

		canvas.drawLine(0, mH/2 , (mChartW + mInterval)*mChartNum, mH/2 , mPaint);

		canvas.restore();

	}

	private float percent = 0;

	private int mW;

	private int mH;

	private int[] mmLs;

	private ChartAnim anim;

	@Override

	protected void onSizeChanged(int w, int h, int oldw, int oldh) {

		super.onSizeChanged(w, h, oldw, oldh);

		this.mW = w;

		this.mH = h;

		initChartData();

	}

	private void initChartData(){

		mmLs = new int[mChartNum];

		for(int i =0 ;i < mmLs.length; i++){

			mmLs[i] = (int)(Math.random()*mH/2);

			Log.d("TAG","initData = " + mmLs[i]);

		}

	}

	public void startAnim(){

		this.startAnimation(anim);

	}

	private class ChartAnim extends Animation{

		/**

		 * 每次系统调用这个方法时， 改变percent的值，

		 * 然后调用postInvalidate()不停的绘制view。

		 */

		@Override

		protected void applyTransformation(float interpolatedTime,

				Transformation t) {

			super.applyTransformation(interpolatedTime, t);

			percent = interpolatedTime;

			postInvalidate();

		}

	}

	public void reset(){

		initChartData();

	}

}