基于Android 实现图片平移、缩放、旋转同时进行
前言
之前因为项目需求，其中使用到了图片的单击显示取消，图片平移缩放功能，昨天突然想再加上图片的旋转功能，在网上看了很多相关的例子，可是没看到能同时实现我想要的功能的。
需求：
（1）图片平移、缩放、旋转等一系列操作后，图片需要自动居中显示。
（2）图片旋转后选自动水平显示或者垂直显示
（3）图片在放大缩小的同时都能旋转
Demo实现部分效果截图
Demo主要代码
Java
MainActivity.java
package com.practice.noyet.rotatezoomimageview;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.graphics.RectF;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;
import com.ypy.eventbus.EventBus;
import java.io.File;
import java.math.BigDecimal;
/**
* package: com.practice.noyet.rotatezoomimageview
* Created by noyet on 2015/11/11.
*/
public class MainActivity extends Activity implements View.OnTouchListener {
private ImageView mImageView;
private PointF point0 = new PointF();
private PointF pointM = new PointF();
private final int NONE = 0;
/**
* 平移
*/
private final int DRAG = 1;
/**
* 旋转、缩放
*/
private final int ZOOM = 2;
/**
* 设定事件模式
*/
private int mode = NONE;
/**
* 图片缩放矩阵
*/
private Matrix matrix = new Matrix();
/**
* 保存触摸前的图片缩放矩阵
*/
private Matrix savedMatrix = new Matrix();
/**
* 保存触点移动过程中的图片缩放矩阵
*/
private Matrix matrix1 = new Matrix();
/**
* 屏幕高度
*/
private int displayHeight;
/**
* 屏幕宽度
*/
private int displayWidth;
/**
* 最小缩放比例
*/
protected float minScale = 1f;
/**
* 最大缩放比例
*/
protected float maxScale = 3f;
/**
* 当前缩放比例
*/
protected float currentScale = 1f;
/**
* 多点触摸2个触摸点间的起始距离
*/
private float oldDist;
/**
* 多点触摸时图片的起始角度
*/
private float oldRotation = 0;
/**
* 旋转角度
*/
protected float rotation = 0;
/**
* 图片初始宽度
*/
private int imgWidth;
/**
* 图片初始高度
*/
private int imgHeight;
/**
* 设置单点触摸退出图片显示时，单点触摸的灵敏度（可针对不同手机单独设置）
*/
protected final int MOVE_MAX = 2;
/**
* 单点触摸时手指触发的‘MotionEvent.ACTION_MOVE'次数
*/
private int fingerNumMove = 0;
private Bitmap bm;
/**
* 保存matrix缩放比例
*/
private float matrixScale= 1;
/*private String imagePath;*/
/**
* 显示被存入缓存中的网络图片
*
* @param event 观察者事件
*/
public void onEventMainThread(CustomEventBus event) {
if (event == null) {
return;
}
if (event.type == CustomEventBus.EventType.SHOW_PICTURE) {
bm = (Bitmap) event.obj;
showImage();
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initData();
}
public void initData() {
// TODO Auto-generated method stub
bm = BitmapFactory.decodeResource(getResources(), R.drawable.alipay);
DisplayMetrics dm = getResources().getDisplayMetrics();
displayWidth = dm.widthPixels;
displayHeight = dm.heightPixels;
mImageView = (ImageView) findViewById(R.id.image_view);
mImageView.setOnTouchListener(this);
showImage();
//显示网络图片时使用
/*File file = MainApplication.getInstance().getImageCache()
.getDiskCache().get(图片路径);
if (!file.exists()) {
Toast.makeText(this, "图片路径错误", Toast.LENGTH_SHORT).show();
} else {
new MyTask().execute(file);
}*/
}
@Override
public boolean onTouch(View view, MotionEvent event) {
ImageView imageView = (ImageView) view;
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
point0.set(event.getX(), event.getY());
mode = DRAG;
System.out.println("MotionEvent--ACTION_DOWN");
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
oldRotation = rotation(event);
savedMatrix.set(matrix);
setMidPoint(pointM, event);
mode = ZOOM;
System.out.println("MotionEvent--ACTION_POINTER_DOWN---" + oldRotation);
break;
case MotionEvent.ACTION_UP:
if (mode == DRAG & (fingerNumMove this.finish();
}
checkView();
centerAndRotate();
imageView.setImageMatrix(matrix);
System.out.println("MotionEvent--ACTION_UP");
fingerNumMove = 0;
break;
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
System.out.println("MotionEvent--ACTION_POINTER_UP");
break;
case MotionEvent.ACTION_MOVE:
operateMove(event);
imageView.setImageMatrix(matrix1);
fingerNumMove++;
System.out.println("MotionEvent--ACTION_MOVE");
break;
}
return true;
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
if (bm != null & !bm.isRecycled()) {
bm.recycle(); // 回收图片所占的内存
System.gc(); // 提醒系统及时回收
}
}
/**
* 显示图片
*/
private void showImage() {
imgWidth = bm.getWidth();
imgHeight = bm.getHeight();
mImageView.setImageBitmap(bm);
matrix.setScale(1, 1);
centerAndRotate();
mImageView.setImageMatrix(matrix);
}
/**
* 触点移动时的操作
*
* @param event 触摸事件
*/
private void operateMove(MotionEvent event) {
matrix1.set(savedMatrix);
switch (mode) {
case DRAG:
matrix1.postTranslate(event.getX() - point0.x, event.getY() - point0.y);
break;
case ZOOM:
rotation = rotation(event) - oldRotation;
float newDist = spacing(event);
float scale = newDist / oldDist;
currentScale = (scale > 3.5f) ? 3.5f : scale;
System.out.println("缩放倍数---" + currentScale);
System.out.println("旋转角度---" + rotation);
/** 縮放 */
matrix1.postScale(currentScale, currentScale, pointM.x, pointM.y);
/** 旋轉 */
matrix1.postRotate(rotation, displayWidth / 2, displayHeight / 2);
break;
}
}
/**
* 两个触点的距离
*
* @param event 触摸事件
* @return float
*/
private float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return (float) Math.sqrt(x * x + y * y);
}
/**
* 获取旋转角度
*/
private float rotation(MotionEvent event) {
double delta_x = (event.getX(0) - event.getX(1));
double delta_y = (event.getY(0) - event.getY(1));
double radians = Math.atan2(delta_y, delta_x);
return (float) Math.toDegrees(radians);
}
/**
* 两个触点的中间坐标
*
* @param pointM 中间坐标
* @param event 触摸事件
*/
private void setMidPoint(PointF pointM, MotionEvent event) {
float x = event.getX(0) + event.getY(1);
float y = event.getY(0) + event.getY(1);
pointM.set(x / 2, y / 2);
}
/**
* 检查约束条件(缩放倍数)
*/
private void checkView() {
if (currentScale > 1) {
if (currentScale * matrixScale > maxScale) {
matrix.postScale(maxScale / matrixScale, maxScale / matrixScale, pointM.x, pointM.y);
matrixScale = maxScale;
} else {
matrix.postScale(currentScale, currentScale, pointM.x, pointM.y);
matrixScale *= currentScale;
}
} else {
if (currentScale * matrixScale else {
matrix.postScale(currentScale, currentScale, pointM.x, pointM.y);
matrixScale *= currentScale;
}
}
}
/**
* 图片居中显示、判断旋转角度 小于（90 * x + 45）度图片旋转（90 * x）度 大于则旋转（90 * (x+1)）
*/
private void centerAndRotate() {
RectF rect = new RectF(0, 0, imgWidth, imgHeight);
matrix.mapRect(rect);
float width = rect.width();
float height = rect.height();
float dx = 0;
float dy = 0;
if (width 2 - width / 2 - rect.left;
} else if (rect.left > 0) {
dx = -rect.left;
} else if (rect.right if (height 2 - height / 2 - rect.top;
} else if (rect.top > 0) {
dy = -rect.top;
} else if (rect.bottom if (rotation != 0) {
int rotationNum = (int) (rotation / 90);
float rotationAvai = new BigDecimal(rotation % 90).setScale(1, BigDecimal.ROUND_HALF_UP).floatValue();
float realRotation = 0;
if (rotation > 0) {
realRotation = rotationAvai > 45 ? (rotationNum + 1) * 90 : rotationNum * 90;
} else if (rotation 0) {
realRotation = rotationAvai 45 ? (rotationNum - 1) * 90 : rotationNum * 90;
}
System.out.println("realRotation: " + realRotation);
matrix.postRotate(realRotation, displayWidth / 2, displayHeight / 2);
rotation = 0;
}
}
/**
* 显示网络图片时使用
*/
private class MyTask extends AsyncTaskFile, File, Bitmap> {
Bitmap bitmap;
String path;
int scale = 1;
long size;
@Override
protected Bitmap doInBackground(File... params) {
// TODO Auto-generated method stub
try {
size = params[0].length();
path = params[0].getAbsolutePath();
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(path, options);
scale = calculateInSampleSize(options, displayWidth,
displayHeight);
options.inJustDecodeBounds = false;
options.inSampleSize = scale;
bitmap = BitmapFactory.decodeFile(path, options);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return bitmap;
}
@Override
protected void onPostExecute(Bitmap result) {
// TODO Auto-generated method stub
EventBus.getDefault().post(
new CustomEventBus(CustomEventBus.EventType.SHOW_PICTURE, result));
}
/**
* 获取图片缩放比例
*
* @param paramOptions Options
* @param paramInt1 宽
* @param paramInt2 高
* @return int
*/
private int calculateInSampleSize(BitmapFactory.Options paramOptions,
int paramInt1, int paramInt2) {
int i = paramOptions.outHeight;
int j = paramOptions.outWidth;
int k = 1;
if ((i > paramInt2) || (j > paramInt1)) {
int m = Math.round(i / paramInt2);
int n = Math.round(j / paramInt1);
k = m return k;
}
}
}
CustomEventBus.java
package com.practice.noyet.rotatezoomimageview;
/**
* package: com.practice.noyet.rotatezoomimageview
* Created by noyet on 2015/11/11.
*/
public class CustomEventBus {
public EventType type;
public Object obj;
public CustomEventBus(EventType type, Object obj) {
this.type = type;
this.obj = obj;
}
enum EventType {
SHOW_PICTURE
}
}
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