涂鸦|绘制|draw|paint|view的绘制|undo|redo|恢复|撤销|保存

<com.cinread.note.view.DrawView
android:id="@+id/paintView"
android:layout_width="match_parent"
android:layout_height="match_parent"/>

package com.cinread.note.view;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;

import com.cinread.note.utils.FileUtils;
import com.cinread.note.utils.LogUtils;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.util.ArrayList;

/**
* @project：Note
* @package：com.cinread.note.view
* @author：pengjf
* @update：2016/4/7
* @desc： TODO
*/
// Created by pengjf on 2016/4/7.
public class DrawView extends View {
private static final float   TOUCH_TOLERANCE = 4;  //thumb width
private              boolean isPaint         = true;

private Bitmap mBitmapInit;
private Bitmap mBitmap;
private Paint  mPaint;
private Paint  mErase;
private Paint  mBitmapPaint;
private Canvas mCanvas;
private Path   mPath;

private float mX;
private float mY;
private int   mWidth;
private int   mHeight;
private ArrayList<Path> paths       = new ArrayList<Path>();
private ArrayList<Path> undonePaths = new ArrayList<Path>();

public DrawView(Context context) {
this(context, null);
}

public DrawView(Context context, AttributeSet attrs) {
super(context, attrs);
mPaint = new Paint();
mErase = new Paint();
initPaint(2);
initErase();
WindowManager manager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
mWidth = manager.getDefaultDisplay().getWidth();
mHeight = manager.getDefaultDisplay().getHeight();
mBitmap = Bitmap.createBitmap(mWidth, mHeight, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
}

private void initPaint(int width) {
mPaint.setDither(true);
mPaint.setAntiAlias(true);
mPaint.setStrokeWidth(width);
mPaint.setColor(Color.BLACK);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
}

private void initErase() {
mErase.setAntiAlias(true);
mErase.setDither(true);
mErase.setStrokeWidth(20);
mErase.setColor(0xFFFFFFFF);
mErase.setStyle(Paint.Style.STROKE);
mErase.setStrokeJoin(Paint.Join.ROUND);
mErase.setStrokeCap(Paint.Cap.ROUND);
mErase.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
}

@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
if (isPaint) {
for (Path p : paths) {
canvas.drawPath(p, mPaint);
LogUtils.d("   - -- -  ");
}
//canvas.drawPath(mPath, mPaint);
} else
canvas.drawPoint(10, 10, mErase);
}

@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
Touch_Down(x, y);
break;
case MotionEvent.ACTION_MOVE:
Touch_Move(x, y);
break;
case MotionEvent.ACTION_UP:
if (isPaint)
Touch_Up(mPaint);
else
Touch_Up(mErase);
break;
}
invalidate();
return true;
}

private void Touch_Down(float x, float y) {
mPath.reset();
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 + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
}
}

private void Touch_Up(Paint paint) {
mPath.lineTo(mX, mY);
mCanvas.drawPath(mPath, paint);
mPath = new Path();
paths.add(mPath);
mPath.reset();
}

public void undo() {
if (paths.size() > 0) {
LogUtils.d("undo " + paths.size());
clearDraw();
undonePaths.add(paths.remove(paths.size() - 1));
invalidate();
}
}

public void redo() {
if (undonePaths.size() > 0) {
LogUtils.d("redo " + undonePaths.size());
clearDraw();
paths.add(undonePaths.remove(undonePaths.size() - 1));
invalidate();
}
}

public void setPaint(int width) {
isPaint = true;
initPaint(width);
invalidate();
}

public void setErase() {
isPaint = false;
initErase();
invalidate();
}

public void setBitmap(String url) {
InputStream is = null;
try {
is = new FileInputStream(url);
mBitmapInit = BitmapFactory.decodeStream(is);
drawBitmapToCanvas(mBitmapInit);
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
FileUtils.close(is);
}
invalidate();
}

public void clearDraw() {
mBitmap = Bitmap.createBitmap(mWidth, mHeight, Bitmap.Config.ARGB_8888);
mCanvas.setBitmap(mBitmap);
invalidate();
}

public void clear() {
paths.clear();
undonePaths.clear();
invalidate();
}

private void drawBitmapToCanvas(Bitmap bitmap) {
if (bitmap.getHeight() > mHeight || bitmap.getWidth() > mWidth) {
RectF rectF = new RectF(0, 0, mWidth, mHeight);
mCanvas.drawBitmap(bitmap, null, rectF, mBitmapPaint);
} else {
mCanvas.drawBitmap(bitmap, 0, 0, mBitmapPaint);
}
}

public void BitmapToPicture(File file, Bitmap bitmap) {
FileOutputStream fos = null;
try {
fos = new FileOutputStream(file);
if (null != fos) {
bitmap.compress(Bitmap.CompressFormat.PNG, 10, fos);
fos.flush();
}
} catch (Exception e) {
e.printStackTrace();
} finally {
FileUtils.close(fos);
}
}
}