android 便签 手写签到demo

package com.handson.game; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.PorterDuffXfermode; import android.graphics.Rect; import android.graphics.PorterDuff.Mode; import android.view.MotionEvent; import android.view.SurfaceHolder; import android.view.SurfaceView; public class TypeNoteDemo extends SurfaceView implements SurfaceHolder.Callback, Runnable { // 定义一个SurfaceHolder private SurfaceHolder holder; // 定义已经写好的文字数组 private Bitmap[] images = new Bitmap[100]; // 当前手写使用的Canvas private Canvas currentCanvas; // 手写绘制的图片 private Bitmap currentBitmap; // 每一行的高度 private int heightPerLine = 32; // 每一个文字的宽度 private int widthForWord = 32; // 每一行的文字数量 private int wordsForLine = 10; // 画笔的宽度 private int widthForPaint = 3; private Paint paintForLine = new Paint(); { paintForLine.setColor(Color.GRAY); } private Paint paintForWord = new Paint(); { paintForWord.setColor(Color.RED); } //用于清空屏幕的Paint private Paint paintForClear = new Paint(); { paintForClear.setColor(Color.TRANSPARENT); paintForClear.setXfermode(new PorterDuffXfermode(Mode.DST)); } // 定义触屏时的坐标 private float oldX, oldY, x, y; // 是否有新画笔 private boolean write = false; // 间隔时间 private int time; //已经写过的文字数量 private int count; public TypeNoteDemo(Context context) { super(context); holder = getHolder(); // 注册回调方法 holder.addCallback(this); // 设置键盘和屏幕可用 setFocusable(true); setFocusableInTouchMode(true); } @Override public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) { // TODO Auto-generated method stub } @Override public void surfaceCreated(SurfaceHolder holder) { // TODO Auto-generated method stub init(); reDraw(); new Thread(this).start(); } @Override public void surfaceDestroyed(SurfaceHolder holder) { // TODO Auto-generated method stub } public void init() { currentBitmap = Bitmap.createBitmap(this.getWidth(), this.getHeight(), Bitmap.Config.ARGB_8888); currentCanvas = new Canvas(currentBitmap); } public void reDraw() { // 锁定画布 Canvas canvas = holder.lockCanvas(); // 设置画布颜色 canvas.drawColor(0xff556677); // 画出直线 for (int i = 0; i < this.getHeight() / heightPerLine; i++) { canvas.drawLine(0, i * heightPerLine, this.getWidth(), i * heightPerLine, paintForLine); } // 绘制写过的文字 for (int i = 0; i < images.length; i++) { if (images[i] != null) { canvas.drawBitmap(images[i], i * widthForWord, (i / wordsForLine) * heightPerLine, null); } } // 绘制手写的Canvas绘制的Bitmap if (currentBitmap != null) { canvas.drawBitmap(currentBitmap, 0, 0, null); } // 解锁，显示内容 holder.unlockCanvasAndPost(canvas); } @Override public boolean onTouchEvent(MotionEvent event) { // TODO Auto-generated method stub switch (event.getAction()) { case MotionEvent.ACTION_DOWN: oldX = event.getX(); oldY = event.getY(); lineTo(event.getX(), event.getY()); break; case MotionEvent.ACTION_MOVE: lineTo(event.getX(), event.getY()); break; case MotionEvent.ACTION_UP: write = true; default: break; } reDraw(); return true; } public void lineTo(float x, float y) { float dx = x - oldX; float dy = y - oldY; if (dx == 0 && dy == 0) { currentCanvas.drawCircle(x, y, widthForPaint, paintForWord); } else if (dx != 0 && dy / dx >= -1 && dy / dx <= 1) { float tan = dy / dx; for (float tmpx = 0; tmpx < dx; tmpx++) { float tmpy = tmpx * tan; currentCanvas.drawCircle(oldX + tmpx, oldY + tmpy, widthForPaint, paintForWord); } for (float tmpx = dx; tmpx < 0; tmpx++) { float tmpy = tmpx * tan; currentCanvas.drawCircle(oldX + tmpx, oldY + tmpy, widthForPaint, paintForWord); } } else if (dy != 0 && dx / dy >= -1 && dx / dy <= 1) { float cot = dx / dy; for (float tmpy = 0; tmpy < dy; tmpy++) { float tmpx = tmpy * cot; currentCanvas.drawCircle(oldX + tmpx, oldY + tmpy, widthForPaint, paintForWord); } for (float tmpy = dy; tmpy < 0; tmpy++) { float tmpx = tmpy * cot; currentCanvas.drawCircle(oldX + tmpx, oldY + tmpy, widthForPaint, paintForWord); } } oldX = x; oldY = y; time = 0; } @Override public void run() { while (true) { long start = System.currentTimeMillis(); try { Thread.sleep(200); } catch (Exception e) { // TODO: handle exception } long end = System.currentTimeMillis(); time += (end - start); if (write && time >= 1000) { write = false; //新建一个小图片 Bitmap imageBitmap = Bitmap.createBitmap(this.widthForWord, this.heightPerLine, Bitmap.Config.ARGB_8888); Canvas imageCanvas = new Canvas(imageBitmap); //手写的文字绘制在小图片中 imageCanvas.drawBitmap(currentBitmap, new Rect(0, 0, this .getWidth(), this.getHeight()), new Rect(0, 0, this.widthForWord, this.heightPerLine), null); images[count]= imageBitmap; count++; //需要清空CurrentCanvas // currentCanvas.drawRect(0, 0, currentCanvas.getWidth(), currentCanvas.getHeight(), paintForClear); currentBitmap.eraseColor(Color.TRANSPARENT); reDraw(); } } } }