package net.micode.notes; import java.io.File; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Date; import java.util.Iterator; import android.app.Activity; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Path; import android.util.AttributeSet; import android.util.DisplayMetrics; import android.view.MotionEvent; import android.view.View; /** * * @category: View实现涂鸦、撤销以及重做功能 * @author: dingruihua * @date: 2022.10.10 * */ public class PaintView extends View { private Canvas mCanvas; private Path mPath; private Paint mBitmapPaint; private Bitmap mBitmap; private Paint mPaint; private ArrayList savePath; private ArrayList deletePath; private DrawPath dp; private float mX, mY; private static final float TOUCH_TOLERANCE = 4; private int bitmapWidth; private int bitmapHeight; public PaintView(Context c) { super(c); //得到屏幕的分辨率 DisplayMetrics dm = new DisplayMetrics(); ((Activity) c).getWindowManager().getDefaultDisplay().getMetrics(dm); bitmapWidth = dm.widthPixels; bitmapHeight = dm.heightPixels - 2 * 45; initCanvas(); savePath = new ArrayList(); deletePath = new ArrayList(); } public PaintView(Context c, AttributeSet attrs) { super(c,attrs); //得到屏幕的分辨率 DisplayMetrics dm = new DisplayMetrics(); ((Activity) c).getWindowManager().getDefaultDisplay().getMetrics(dm); bitmapWidth = dm.widthPixels; bitmapHeight = dm.heightPixels - 2 * 45; initCanvas(); savePath = new ArrayList(); deletePath = new ArrayList(); } //初始化画布 public void initCanvas(){ mPaint = new Paint(); mPaint.setAntiAlias(true); mPaint.setDither(true); mPaint.setColor(0xFF00FF00); mPaint.setStyle(Paint.Style.STROKE); mPaint.setStrokeJoin(Paint.Join.ROUND); mPaint.setStrokeCap(Paint.Cap.ROUND); mPaint.setStrokeWidth(10); mBitmapPaint = new Paint(Paint.DITHER_FLAG); //画布大小 mBitmap = Bitmap.createBitmap(bitmapWidth, bitmapHeight, Bitmap.Config.RGB_565); mCanvas = new Canvas(mBitmap); //所有mCanvas画的东西都被保存在了mBitmap中 mCanvas.drawColor(Color.WHITE); mPath = new Path(); mBitmapPaint = new Paint(Paint.DITHER_FLAG); } @Override protected void onDraw(Canvas canvas) { canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint); //显示旧的画布 if (mPath != null) { // 实时的显示 canvas.drawPath(mPath, mPaint); } } //路径对象 class DrawPath{ Path path; Paint paint; } /** * 撤销的核心思想就是将画布清空， * 将保存下来的Path路径最后一个移除掉， * 重新将路径画在画布上面。 */ public void undo(){ System.out.println(savePath.size()+"--------------"); if(savePath != null && savePath.size() > 0){ //调用初始化画布函数以清空画布 initCanvas(); //将路径保存列表中的最后一个元素删除 ,并将其保存在路径删除列表中 DrawPath drawPath = savePath.get(savePath.size() - 1); deletePath.add(drawPath); savePath.remove(savePath.size() - 1); //将路径保存列表中的路径重绘在画布上 Iterator iter = savePath.iterator(); //重复保存 while (iter.hasNext()) { DrawPath dp = iter.next(); mCanvas.drawPath(dp.path, dp.paint); } invalidate();// 刷新 } } /** * 恢复的核心思想就是将撤销的路径保存到另外一个列表里面(栈)， * 然后从redo的列表里面取出最顶端对象， * 画在画布上面即可 */ public void redo(){ if(deletePath.size() > 0){ //将删除的路径列表中的最后一个，也就是最顶端路径取出（栈）,并加入路径保存列表中 DrawPath dp = deletePath.get(deletePath.size() - 1); savePath.add(dp); //将取出的路径重绘在画布上 mCanvas.drawPath(dp.path, dp.paint); //将该路径从删除的路径列表中去除 deletePath.remove(deletePath.size() - 1); invalidate(); } } /* * 清空的主要思想就是初始化画布 * 将保存路径的两个List清空 * */ public void removeAllPaint(){ //调用初始化画布函数以清空画布 initCanvas(); invalidate();//刷新 savePath.clear(); deletePath.clear(); } /* * 保存所绘图形 * 返回绘图文件的存储路径 * public String saveBitmap(){ //获得系统当前时间，并以该时间作为文件名 SimpleDateFormat formatter = new SimpleDateFormat ("yyyyMMddHHmmss"); Date curDate = new Date(System.currentTimeMillis());//获取当前时间 String str = formatter.format(curDate); String paintPath = ""; str = str + "paint.png"; File dir = new File("/sdcard/notes/"); File file = new File("/sdcard/notes/",str); if (!dir.exists()) { dir.mkdir(); } else{ if(file.exists()){ file.delete(); } } try { FileOutputStream out = new FileOutputStream(file); mBitmap.compress(Bitmap.CompressFormat.PNG, 100, out); out.flush(); out.close(); //保存绘图文件路径 paintPath = "/sdcard/notes/" + str; } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return paintPath; }*/ private void touch_start(float x, float y) { mPath.reset();//清空path mPath.moveTo(x, y); mX = x; mY = y; } private void touch_move(float x, float y) { float dx = Math.abs(x - mX); float dy = Math.abs(y - mY); if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) { //mPath.quadTo(mX, mY, x, y); mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);//源代码是这样写的，可是我没有弄明白，为什么要这样？ mX = x; mY = y; } } private void touch_up() { mPath.lineTo(mX, mY); mCanvas.drawPath(mPath, mPaint); savePath.add(dp); mPath = null; } @Override public boolean onTouchEvent(MotionEvent event) { float x = event.getX(); float y = event.getY(); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: mPath = new Path(); dp = new DrawPath(); dp.path = mPath; dp.paint = mPaint; touch_start(x, y); invalidate(); //清屏 break; case MotionEvent.ACTION_MOVE: touch_move(x, y); invalidate(); break; case MotionEvent.ACTION_UP: touch_up(); invalidate(); break; } return true; } }