package com.electric.chargingpile.view;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;

import com.electric.chargingpile.R;

public class ImageShowActivity extends Activity {

    private ImageView imageShow;
    private static String tag = "ResolvePicture";
    private String[] imageUrls;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_image_show);
        initView();
    }

    private void initView() {
        imageShow = (ImageView) findViewById(R.id.imageShow);
//        Bitmap bitmap = BitmapFactory.decodeResource(getResources(),
//                R.drawable.yd1_625);
//        imageShow.setImageDrawable(resizeImage2("/storage/emulated/0/alterandroidapp.jpg", 200, 100));
        imageUrls = getIntent().getStringArrayExtra("url");
//        imageShow.setImageDrawable();
        imageShow.setOnTouchListener(new TouchListener());

    }

    //使用BitmapFactory.Options的inSampleSize参数来缩放
    public static Drawable resizeImage2(String path,
                                        int width, int height) {
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;//不加载bitmap到内存中
        BitmapFactory.decodeFile(path, options);
        int outWidth = options.outWidth;
        int outHeight = options.outHeight;
        options.inDither = false;
        options.inPreferredConfig = Bitmap.Config.ARGB_8888;
        options.inSampleSize = 1;

        if (outWidth != 0 && outHeight != 0 && width != 0 && height != 0) {
            int sampleSize = (outWidth / width + outHeight / height) / 2;
            Log.d(tag, "sampleSize = " + sampleSize);
            options.inSampleSize = sampleSize;
        }

        options.inJustDecodeBounds = false;
        return new BitmapDrawable(BitmapFactory.decodeFile(path, options));
    }

    public static Drawable resizeImage(Bitmap bitmap, int w, int h) {
        Bitmap BitmapOrg = bitmap;
        int width = BitmapOrg.getWidth();
        int height = BitmapOrg.getHeight();
        int newWidth = w;
        int newHeight = h;

        float scaleWidth = ((float) newWidth) / width;
        float scaleHeight = ((float) newHeight) / height;

        Matrix matrix = new Matrix();
        matrix.postScale(scaleWidth, scaleHeight);
        // if you want to rotate the Bitmap
        // matrix.postRotate(45);
        Bitmap resizedBitmap = Bitmap.createBitmap(BitmapOrg, 0, 0, width,
                height, matrix, true);
        return new BitmapDrawable(resizedBitmap);
    }

    private final class TouchListener implements View.OnTouchListener {

        /**
         * 记录是拖拉照片模式还是放大缩小照片模式
         */
        private int mode = 0;// 初始状态
        /**
         * 拖拉照片模式
         */
        private static final int MODE_DRAG = 1;
        /**
         * 放大缩小照片模式
         */
        private static final int MODE_ZOOM = 2;

        /**
         * 用于记录开始时候的坐标位置
         */
        private PointF startPoint = new PointF();
        /**
         * 用于记录拖拉图片移动的坐标位置
         */
        private Matrix matrix = new Matrix();
        /**
         * 用于记录图片要进行拖拉时候的坐标位置
         */
        private Matrix currentMatrix = new Matrix();

        /**
         * 两个手指的开始距离
         */
        private float startDis;
        /**
         * 两个手指的中间点
         */
        private PointF midPoint;

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            /** 通过与运算保留最后八位 MotionEvent.ACTION_MASK = 255 */
            switch (event.getAction() & MotionEvent.ACTION_MASK) {
                // 手指压下屏幕
                case MotionEvent.ACTION_DOWN:
                    mode = MODE_DRAG;
                    // 记录ImageView当前的移动位置
                    currentMatrix.set(imageShow.getImageMatrix());
                    startPoint.set(event.getX(), event.getY());
                    break;
                // 手指在屏幕上移动，改事件会被不断触发
                case MotionEvent.ACTION_MOVE:
                    // 拖拉图片
                    if (mode == MODE_DRAG) {
                        float dx = event.getX() - startPoint.x; // 得到x轴的移动距离
                        float dy = event.getY() - startPoint.y; // 得到x轴的移动距离
                        // 在没有移动之前的位置上进行移动
                        matrix.set(currentMatrix);
                        matrix.postTranslate(dx, dy);
                    }
                    // 放大缩小图片
                    else if (mode == MODE_ZOOM) {
                        float endDis = distance(event);// 结束距离
                        if (endDis > 10f) { // 两个手指并拢在一起的时候像素大于10
                            float scale = endDis / startDis;// 得到缩放倍数
                            matrix.set(currentMatrix);
                            matrix.postScale(scale, scale, midPoint.x, midPoint.y);
                        }
                    }
                    break;
                // 手指离开屏幕
                case MotionEvent.ACTION_UP:
                    // 当触点离开屏幕，但是屏幕上还有触点(手指)
                case MotionEvent.ACTION_POINTER_UP:
                    mode = 0;
                    break;
                // 当屏幕上已经有触点(手指)，再有一个触点压下屏幕
                case MotionEvent.ACTION_POINTER_DOWN:
                    mode = MODE_ZOOM;
                    /** 计算两个手指间的距离 */
                    startDis = distance(event);
                    /** 计算两个手指间的中间点 */
                    if (startDis > 10f) { // 两个手指并拢在一起的时候像素大于10
                        midPoint = mid(event);
                        //记录当前ImageView的缩放倍数
                        currentMatrix.set(imageShow.getImageMatrix());
                    }
                    break;
            }
            imageShow.setImageMatrix(matrix);
            return true;
        }

        /**
         * 计算两个手指间的距离
         */
        private float distance(MotionEvent event) {
            float dx = event.getX(1) - event.getX(0);
            float dy = event.getY(1) - event.getY(0);
            /** 使用勾股定理返回两点之间的距离 */
            return (float) Math.sqrt(dx * dx + dy * dy);
        }

        /**
         * 计算两个手指间的中间点
         */
        private PointF mid(MotionEvent event) {
            float midX = (event.getX(1) + event.getX(0)) / 2;
            float midY = (event.getY(1) + event.getY(0)) / 2;
            return new PointF(midX, midY);
        }

    }

}