android 涂鸦

public class PaintView extends View {

	private Canvas mCanvas;
	private Path mPath;
	private Paint mPaint;
	private float mX, mY;
	private Bitmap imgBitmap;


	private static final float TOUCH_TOLERANCE = 4;

	/**
	 * 构造
	 * 
	 * @param context
	 * @param width
	 *            屏幕宽度
	 * 
	 * @param height
	 *            屏幕高度
	 * 
	 */

	public PaintView(Context context, Bitmap bm, Paint paint) {
		super(context);
		this.imgBitmap = bm;
		this.mPaint = paint;
		mCanvas = new Canvas(imgBitmap);
		mPath = new Path();
	}

	@Override
	protected void onSizeChanged(int w, int h, int oldw, int oldh) {
		super.onSizeChanged(w, h, oldw, oldh);
	}

	@Override
	protected void onDraw(Canvas canvas) {
		canvas.drawBitmap(imgBitmap, 0, 0, mPaint);
		canvas.drawPath(mPath, mPaint);
		canvas.save(Canvas.ALL_SAVE_FLAG);
		canvas.restore();
	}

	public Bitmap getBitmap() {
		return imgBitmap;
	}

	/**
	 * 屏幕触摸开始
	 * 
	 * @param x
	 *            X坐标
	 * @param y
	 *            Y坐标
	 */
	private void touchStart(float x, float y) {
		mPath.reset();
		mPath.moveTo(x, y);
		this.mX = x;
		this.mY = y;
	}

	private void touchUp() {
		mPath.lineTo(mX, mY);
		mCanvas.drawPath(mPath, mPaint);
		mPath.reset();
	}

	private void touchMove(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 + mX) / 2, (y + mY) / 2);
			mX = x;
			mY = y;
		}
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		float x = event.getX();
		float y = event.getY();

		switch (event.getAction()) {
		case MotionEvent.ACTION_DOWN:
			touchStart(x, y);
			invalidate();
			break;
		case MotionEvent.ACTION_MOVE:
			touchMove(x, y);
			invalidate();
			break;
		case MotionEvent.ACTION_UP:
			touchUp();
			invalidate();
			break;
		default:
			break;
		}

		return true;

	}

}

private Paint mPaint;
	private MaskFilter mEmboss;
	private MaskFilter mBlur;	
	Bitmap bitmap;
	PaintView paintView;		
	LinearLayout linearLayout;	
	Bitmap imageBitmap;
	

	public static final String MIME_TYPE_IMAGE_JPEG = "image/jpeg";
	public static final int ACTIVITY_GET_IMAGE = 0;
	private byte[] mContent;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		this.setContentView(R.layout.paint);
		
	
		
		mPaint = new Paint();
		mPaint.setAntiAlias(true); 
		
		mPaint.setStyle(Paint.Style.STROKE);
		mPaint.setStrokeWidth(6); 
		mEmboss=new EmbossMaskFilter(new float[] { 1, 1, 1 }, 0.4f, 6, 3.5f);
		mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL);
		linearLayout = (LinearLayout) findViewById(R.id.linearLayout);
		
		//默认为灰色背景
		mPaint.setColor(0xFFFF0000);	

	}
	

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// 填充选项菜单
		MenuInflater inflater = getMenuInflater();		 
		SubMenu choosepicMenu = menu.addSubMenu(0,1,1,"选择图片");  
		SubMenu boldMenu = menu.addSubMenu(0,2,2,"线条粗细");
		SubMenu effectMenu=menu.addSubMenu(0,3,3,"线条效果");
		effectMenu.add(11, 7, 1, "浮雕");
		effectMenu.add(11, 8, 2, "空心");
		effectMenu.add(11, 9, 3, "模糊");
		effectMenu.add(11, 10, 4, "正常");
		SubMenu colorMenu=menu.addSubMenu(0,4,4,"线条颜色");
		SubMenu clearMenu=menu.addSubMenu(0,5,5,"清除");
		SubMenu saveMenu=menu.addSubMenu(0,6,6,"保存");

		return super.onCreateOptionsMenu(menu);
	}

	@Override
	public boolean onOptionsItemSelected(MenuItem item) {
		
		switch (item.getItemId()) {
		case 1:			
			Intent getImage = new Intent(Intent.ACTION_GET_CONTENT);
			getImage.addCategory(Intent.CATEGORY_OPENABLE);
			getImage.setType(MIME_TYPE_IMAGE_JPEG);
			startActivityForResult(getImage, ACTIVITY_GET_IMAGE);
			
			break;
		case 2:
			Toast.makeText(this, "线条粗细", Toast.LENGTH_LONG).show();
			break;
		case 4:
			new ColorPickerDialog(this, this, mPaint.getColor()).show();
			break;
		case 5: //清除
			break;
		case 6: //保存图片
			Bitmap bitmap = paintView.getBitmap();
			FileOutputStream fos = null;
			String filepath="/sdcard/"+System.currentTimeMillis()+".jpg";
			try {
				
				fos = new FileOutputStream(filepath);
			} catch (FileNotFoundException e) {

				e.printStackTrace();
			}
			bitmap.compress(Bitmap.CompressFormat.JPEG, 90, fos);
			Toast.makeText(this, "图片文件已经保存到"+filepath +" 。",Toast.LENGTH_LONG).show();
			try {
				fos.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
			break;
		case 7: //浮雕
            mPaint.setMaskFilter(mEmboss);
  			break;
		case 8 :
			
			break;
		case 9: 
			mPaint.setMaskFilter(mBlur);
			break;
		case 10:
			mPaint.setMaskFilter(null);
		default:
			break;
		}
		
		return super.onOptionsItemSelected(item);
	}

	@Override
	public void colorChanged(int color) {
		mPaint.setColor(color);		
	}
	
	
	@Override
	protected void onActivityResult(int requestCode, int resultCode, Intent data) {

		if (resultCode != RESULT_OK) {
			return;
		}

		ContentResolver resolver = getContentResolver();

		if (requestCode == ACTIVITY_GET_IMAGE) {
			try {
				Uri originalUri = data.getData();
				mContent = getBytesFromInputStream(resolver.openInputStream(Uri
						.parse(originalUri.toString())), 3500000);
				imageBitmap = getPicFromBytes(mContent, null);
				
				bitmap = Bitmap.createBitmap(imageBitmap, 0, 0, imageBitmap.getWidth(), imageBitmap
						.getHeight());
				Bitmap b=bitmap.copy(Bitmap.Config.ARGB_8888, true);
				
				paintView = new PaintView(this, b, mPaint);
				linearLayout.removeAllViews();
				linearLayout.addView(paintView);
				
				b=null;
				imageBitmap=null;
				
			} catch (IOException e) {
				System.out.println(e.getMessage());
			}

		}

	}

	public static Bitmap getPicFromBytes(byte[] bytes,
			BitmapFactory.Options opts) {

		if (bytes != null)
			if (opts != null) {
				return BitmapFactory.decodeByteArray(bytes, 0, bytes.length,
						opts);
			} else {
				return BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
			}
		return null;
	}

	public static byte[] getBytesFromInputStream(InputStream is, int bufsiz)
			throws IOException {
		int total = 0;
		byte[] bytes = new byte[4096];
		ByteBuffer bb = ByteBuffer.allocate(bufsiz);

		while (true) {
			int read = is.read(bytes);
			if (read == -1)
				break;
			bb.put(bytes, 0, read);
			total += read;
		}

		byte[] content = new byte[total];
		bb.flip();
		bb.get(content, 0, total);

		return content;
	}