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自定义view实现涂鸦(画板)功能

时间:2016-05-30 15:38:05      阅读:313      评论:0      收藏:0      [点我收藏+]

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自定义view实现涂鸦功能,包括撤销、恢复、重做、保存以及橡皮擦(在风格中实现)功能,小模块包括画笔颜色调整、画笔尺寸调整、画笔类型(包括正常画笔以及橡皮擦功能),之后又陆续实现了画圆、画矩形以及画箭头的功能,这里我们先完成前面的需求

撤销:

/**
     * 撤销
     * 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() {
        if (savePath != null && savePath.size() > 0) {
            DrawPath drawPath = savePath.get(savePath.size() - 1);
            deletePath.add(drawPath);
            savePath.remove(savePath.size() - 1);
            redrawOnBitmap();
        }
    }

重做:
/**
     * 重做 www.2cto.com
     */
    public void redo() {
        if (savePath != null && savePath.size() > 0) {
            savePath.clear();
            redrawOnBitmap();
        }
    }

完成以上两项功能的重要模块

private void redrawOnBitmap() {
        initCanvas();
        Iterator<DrawPath> iter = savePath.iterator();
        while (iter.hasNext()) {
            DrawPath drawPath = iter.next();
            mCanvas.drawPath(drawPath.path, drawPath.paint);
        }
        invalidate();// 刷新
    }

原理:通过onTouch()方法完成,当down时创建path类,并记录起点,up时获取重点位置,并将该条路径存入path实体类中,之后将该path存入一个集合savepath集合中。撤销时,删除最上层的path,重做则是删除所有path即可。


恢复:

/**
     * 恢复,恢复的核心就是将删除的那条路径重新添加到savapath中重新绘画即可
     */
    public void recover() {
        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();
        }
    }
原理:创建另外一个集合deletaPath用来存放撤销时删除的path,当需要恢复时将该集合中的path重新放入savePath集合中,重新画在画板上,之后savepath中移除该path,invalidate()即可

保存:

//保存到sd卡
    public void saveToSDCard() {
        //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) + "paint.png";
        File file = new File("sdcard/" + str);
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(file);
        } catch (Exception e) {
            e.printStackTrace();
        }
        mBitmap.compress(CompressFormat.PNG, 100, fos);
        //发送Sd卡的就绪广播,要不然在手机图库中不存在
        Intent intent = new Intent(Intent.ACTION_MEDIA_MOUNTED);
        intent.setData(Uri.fromFile(Environment.getExternalStorageDirectory()));
        context.sendBroadcast(intent);
        Log.e("TAG", "图片已保存");
    }

原理很简单存到本地即可,但是我们在存储时可以记录当前时间,以当前时间为图片名字以示区别,注意:可以发广播,不发的话可能造成用户无法在图库中查看到(如果配置的是临时路径建议不添加)


样式修改:画板样式,画笔尺寸,画笔颜色

//以下为样式修改内容
    //设置画笔样式
    public void selectPaintStyle(int which) {
        if (which == 0) {
            currentStyle = 1;
            setPaintStyle();
        }
        //当选择的是橡皮擦时,设置颜色为白色
        if (which == 1) {
            currentStyle = 2;
            setPaintStyle();
            mPaint.setStrokeWidth(20);
        }
    }
    //选择画笔大小
    public void selectPaintSize(int which){
        int size =Integer.parseInt(this.getResources().getStringArray(R.array.paintsize)[which]);
        currentSize = size;
        setPaintStyle();
    }
    //设置画笔颜色
    public void selectPaintColor(int which){
        currentColor = paintColor[which];
        setPaintStyle();
    }

//初始化画笔样式
    private void setPaintStyle() {
        mPaint = new Paint();
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setStrokeJoin(Paint.Join.ROUND);// 设置外边缘
        mPaint.setStrokeCap(Paint.Cap.ROUND);// 形状
        mPaint.setAntiAlias(true);
        mPaint.setDither(true);
        if (currentStyle == 1) {//普通画笔功能
            mPaint.setStrokeWidth(currentSize);
            mPaint.setColor(currentColor);
        } else {//橡皮擦
            mPaint.setAlpha(0);
            mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));//这两个方法一起使用才能出现橡皮擦效果
            mPaint.setColor(Color.TRANSPARENT);
            mPaint.setStrokeWidth(50);
            currentDrawGraphics = DRAW_PATH;//使用橡皮擦时默认用线的方式擦除
        }
    }


橡皮擦功能:
基本原理:橡皮擦就是用和画布颜色一致颜色的画笔在屏幕触摸,简接实现橡皮擦的功能。
1)初始化画笔,并且设置画笔的颜色为白色(这里其实要设置为画布的颜色)。
2)设置画笔的大小为合适的大小。
3)用一个变量记住橡皮擦的颜色,用于在其他操作后重新使用橡皮擦。

以上为简易的橡皮擦主要使用白色来覆盖,但当背景图为一张照片时是不可行的,因为白色会很明显的展示在背景图上,而且需要注意的是:即使是将画笔颜色变为透明色也是不可行的,综上我们选择用渲染模式来处理
这里选择渲染模式Xfermode的DIS_IN,这样我们处理后会发现出现黑色阴影边框,效果实现了,但是bug非常明显
之后选择渲染模式的CLEAR这个模式会擦除所有像素点,但是发现是以黑色线条的形式去擦除的
通过STACK OVER FLOW网站超找到两者解决办法:
1.改变touch_move方法的path画图的相关方法,效果实现了但是对撤销和重做造成了一定影响,最终没有选用

private void touch_move(float x, float y) {
        float dx = Math.abs(x - mX);
        float dy = Math.abs(mY - y);
        if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
            // 从x1,y1到x2,y2画一条贝塞尔曲线,更平滑(直接用mPath.lineTo也可以)
           // mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
            mPath.lineTo(mX, mY);
            mCanvas.drawPath(mPath, mPaint);
            //将一条完整的路径保存下来(相当于入栈操作)
            savePath.add(dp);
            mPath.reset();
            mPath.moveTo(mX, mY);
            mX = x;
            mY = y;
        }
    }
    private void touch_up() {
        mPath = null;// 重新置空
        //mPath.reset();
    }
2.最终发现只需要设置默认type就能解决该问题

 setLayerType(LAYER_TYPE_SOFTWARE,null);//设置默认样式,去除dis-in的黑色方框以及clear模式的黑线效果

还需要设置在不加背景图时设置背景资源为0,0即代表显示默认背景颜色(一般为白色)


橡皮擦相关代码:

if (currentStyle == 1) {//正常画笔
            mPaint.setStrokeWidth(currentSize);
            mPaint.setColor(currentColor);
        } else {//橡皮擦
            mPaint.setAlpha(0);
            mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
            mPaint.setColor(Color.TRANSPARENT);
            mPaint.setStrokeWidth(50);
        }
注意 mPaint.setAlpha(0);mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));两者搭配使用


设置画笔大小的功能:
1)初始化画笔。
2)设置画笔的大小为所选择的大小。
3)用一个变量记住当前画笔的大小,用于在进行其他操作后还保持之前设置的画笔大小。

设置画笔颜色的功能:
1)初始化画笔。
2)设置画笔的颜色为所选择的颜色。
3)用一个变量记住当前画笔的颜色,用于在进行其他操作后还保持之前设置的画笔颜色。


以下为完整代码:
布局:

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自定义TuyaView:

package com.banhai.paintboard;
/**
 * Created by zhaopengxiang on 2016/4/6.
 * View实现涂鸦、撤销以及重做功能
 */
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.net.Uri;
import android.os.Environment;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import java.io.File;
import java.io.FileOutputStream;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
public class TuyaView extends View {
    private Context context;
    private Bitmap mBitmap;
    private Canvas mCanvas;
    private Path mPath;
    private Paint mBitmapPaint;// 画布的画笔
    private Paint mPaint;// 真实的画笔
    private float mX, mY;// 临时点坐标
    private static final float TOUCH_TOLERANCE = 4;
    // 保存Path路径的集合,用List集合来模拟栈
    private static List<DrawPath> savePath;
    // 保存已删除Path路径的集合
    private static List<DrawPath> deletePath;
    // 记录Path路径的对象
    private DrawPath dp;
    private int screenWidth, screenHeight;
    private int currentColor = Color.RED;
    private int currentSize = 5;
    private int currentStyle = 1;
    private int[] paintColor;//颜色集合
    private class DrawPath {
        public Path path;// 路径
        public Paint paint;// 画笔
    }
    public TuyaView(Context context, int w, int h) {
        super(context);
        this.context = context;
        screenWidth = w;
        screenHeight = h;
        paintColor = new int[]{
                Color.RED, Color.BLUE, Color.GREEN, Color.YELLOW, Color.BLACK, Color.GRAY, Color.CYAN
        };
        setLayerType(LAYER_TYPE_SOFTWARE,null);//设置默认样式,去除dis-in的黑色方框以及clear模式的黑线效果
        initCanvas();
        savePath = new ArrayList<DrawPath>();
        deletePath = new ArrayList<DrawPath>();
    }
    public void initCanvas() {
        setPaintStyle();
        mBitmapPaint = new Paint(Paint.DITHER_FLAG);
        //画布大小
        mBitmap = Bitmap.createBitmap(screenWidth, screenHeight, Bitmap.Config.ARGB_8888);
        mBitmap.eraseColor(Color.argb(0, 0, 0, 0));
        mCanvas = new Canvas(mBitmap);  //所有mCanvas画的东西都被保存在了mBitmap中
        mCanvas.drawColor(Color.TRANSPARENT);
    }
    //初始化画笔样式
    private void setPaintStyle() {
        mPaint = new Paint();
        mPaint.setStyle(Paint.Style.STROKE);
        mPaint.setStrokeJoin(Paint.Join.ROUND);// 设置外边缘
        mPaint.setStrokeCap(Paint.Cap.ROUND);// 形状
        mPaint.setAntiAlias(true);
        mPaint.setDither(true);
        if (currentStyle == 1) {
            mPaint.setStrokeWidth(currentSize);
            mPaint.setColor(currentColor);
        } else {//橡皮擦
            mPaint.setAlpha(0);
            mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
            mPaint.setColor(Color.TRANSPARENT);
            mPaint.setStrokeWidth(50);
        }
    }
    @Override
    public void onDraw(Canvas canvas) {
        //canvas.drawColor(0xFFAAAAAA);
        // 将前面已经画过得显示出来
        canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
        if (mPath != null) {
            // 实时的显示
            canvas.drawPath(mPath, mPaint);
        }
    }
    private void touch_start(float x, float y) {
        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(mY - y);
        if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
            // 从x1,y1到x2,y2画一条贝塞尔曲线,更平滑(直接用mPath.lineTo也可以)
            mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
            //mPath.lineTo(mX,mY);
            mX = x;
            mY = y;
        }
    }
    private void touch_up() {
        mPath.lineTo(mX, mY);
        mCanvas.drawPath(mPath, mPaint);
        //将一条完整的路径保存下来(相当于入栈操作)
        savePath.add(dp);
        mPath = null;// 重新置空
    }
    /**
     * 撤销
     * 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() {
        if (savePath != null && savePath.size() > 0) {
            DrawPath drawPath = savePath.get(savePath.size() - 1);
            deletePath.add(drawPath);
            savePath.remove(savePath.size() - 1);
            redrawOnBitmap();
        }
    }
    /**
     * 重做
     */
    public void redo() {
        if (savePath != null && savePath.size() > 0) {
            savePath.clear();
            redrawOnBitmap();
        }
    }
    private void redrawOnBitmap() {
        /*mBitmap = Bitmap.createBitmap(screenWidth, screenHeight,
                Bitmap.Config.RGB_565);
        mCanvas.setBitmap(mBitmap);// 重新设置画布,相当于清空画布*/
        initCanvas();
        Iterator<DrawPath> iter = savePath.iterator();
        while (iter.hasNext()) {
            DrawPath drawPath = iter.next();
            mCanvas.drawPath(drawPath.path, drawPath.paint);
        }
        invalidate();// 刷新
    }
    /**
     * 恢复,恢复的核心就是将删除的那条路径重新添加到savapath中重新绘画即可
     */
    public void recover() {
        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();
        }
    }
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        float x = event.getX();
        float y = event.getY();
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                // 每次down下去重新new一个Path
                mPath = new Path();
                //每一次记录的路径对象是不一样的
                dp = new DrawPath();
                dp.path = mPath;
                dp.paint = mPaint;
                touch_start(x, y);
                invalidate();
                break;
            case MotionEvent.ACTION_MOVE:
                touch_move(x, y);
                invalidate();
                break;
            case MotionEvent.ACTION_UP:
                touch_up();
                invalidate();
                break;
        }
        return true;
    }
    //保存到sd卡
    public void saveToSDCard() {
        //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) + "paint.png";
        File file = new File("sdcard/" + str);
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(file);
        } catch (Exception e) {
            e.printStackTrace();
        }
        mBitmap.compress(CompressFormat.PNG, 100, fos);
        //发送Sd卡的就绪广播,要不然在手机图库中不存在
        Intent intent = new Intent(Intent.ACTION_MEDIA_MOUNTED);
        intent.setData(Uri.fromFile(Environment.getExternalStorageDirectory()));
        context.sendBroadcast(intent);
        Log.e("TAG", "图片已保存");
    }
    //以下为样式修改内容
    //设置画笔样式
    public void selectPaintStyle(int which) {
        if (which == 0) {
            currentStyle = 1;
            setPaintStyle();
        }
        //当选择的是橡皮擦时,设置颜色为白色
        if (which == 1) {
            currentStyle = 2;
            setPaintStyle();
        }
    }
    //选择画笔大小
    public void selectPaintSize(int which) {
        //int size = Integer.parseInt(this.getResources().getStringArray(R.array.paintsize)[which]);
        currentSize = which;
        setPaintStyle();
    }
    //设置画笔颜色
    public void selectPaintColor(int which) {
        currentColor = paintColor[which];
        setPaintStyle();
    }
}

MainActivity:

package com.banhai.paintboard;
import android.content.DialogInterface;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Display;
import android.view.View;
import android.view.Window;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.SeekBar;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
    private FrameLayout frameLayout;
    private Button btn_undo;
    private Button btn_redo;
    private Button btn_save;
    private Button btn_recover;
    private TuyaView tuyaView;//自定义涂鸦板
    private Button btn_paintcolor;
    private Button btn_paintsize;
    private Button btn_paintstyle;
    private SeekBar sb_size;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.activity_main);
        initView();
        initData();
        initListener();
    }
    private void initView() {
        frameLayout = (FrameLayout) findViewById(R.id.fl_boardcontainer);
        btn_undo = (Button) findViewById(R.id.btn_last);
        btn_redo = (Button) findViewById(R.id.btn_redo);
        btn_save = (Button) findViewById(R.id.btn_savesd);
        btn_recover = (Button) findViewById(R.id.btn_recover);
        btn_paintcolor = (Button) findViewById(R.id.btn_paintcolor);
        btn_paintsize = (Button) findViewById(R.id.btn_paintsize);
        btn_paintstyle = (Button) findViewById(R.id.btn_paintstyle);
        sb_size = (SeekBar) findViewById(R.id.sb_size);
    }
    private void initData() {
        //虽然此时获取的是屏幕宽高,但是我们可以通过控制framlayout来实现控制涂鸦板大小
        Display defaultDisplay = getWindowManager().getDefaultDisplay();
        int screenWidth = defaultDisplay.getWidth();
        int screenHeight = defaultDisplay.getHeight();
        tuyaView = new TuyaView(this,screenWidth,screenHeight);
        frameLayout.addView(tuyaView);
        tuyaView.requestFocus();
        tuyaView.selectPaintSize(sb_size.getProgress());
    }
    private void initListener() {
        btn_undo.setOnClickListener(this);
        btn_redo.setOnClickListener(this);
        btn_save.setOnClickListener(this);
        btn_recover.setOnClickListener(this);
        btn_paintcolor.setOnClickListener(this);
        btn_paintsize.setOnClickListener(this);
        btn_paintstyle.setOnClickListener(this);
        sb_size.setOnSeekBarChangeListener(new MySeekChangeListener());
    }
     class MySeekChangeListener implements SeekBar.OnSeekBarChangeListener {
        @Override
        public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
            tuyaView.selectPaintSize(seekBar.getProgress());
            //Toast.makeText(MainActivity.this,"当前画笔尺寸为"+seekBar.getProgress(),Toast.LENGTH_SHORT ).show();
        }
         @Override
         public void onStartTrackingTouch(SeekBar seekBar) {
             tuyaView.selectPaintSize(seekBar.getProgress());
             //Toast.makeText(MainActivity.this,"当前画笔尺寸为"+seekBar.getProgress(),Toast.LENGTH_SHORT ).show();
         }
         @Override
        public void onStopTrackingTouch(SeekBar seekBar) {}
    }
    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.btn_last://撤销
                tuyaView.undo();
                break;
            case R.id.btn_redo://重做
                tuyaView.redo();
                break;
            case R.id.btn_recover://恢
                tuyaView.recover();
                break;
            case R.id.btn_savesd://保存
                tuyaView.saveToSDCard();
                break;
            case R.id.btn_paintcolor:
                sb_size.setVisibility(View.GONE);
                showPaintColorDialog(v);
                break;
            case R.id.btn_paintsize:
                sb_size.setVisibility(View.VISIBLE);
                break;
            case R.id.btn_paintstyle:
                sb_size.setVisibility(View.GONE);
                showMoreDialog(v);
                break;
        }
    }
    private int select_paint_color_index = 0;
    private int select_paint_style_index = 0;
    //private int select_paint_size_index = 0;
    public void showPaintColorDialog(View parent){
        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
        alertDialogBuilder.setTitle("选择画笔颜色:");
        alertDialogBuilder.setSingleChoiceItems(R.array.paintcolor, select_paint_color_index, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                select_paint_color_index = which;
                tuyaView.selectPaintColor(which);
                dialog.dismiss();
            }
        });
        alertDialogBuilder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();
            }
        });
        alertDialogBuilder.create().show();
    }
/*
//弹出画笔大小选项对话框
    public void showPaintSizeDialog(View parent){
        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
        alertDialogBuilder.setTitle("选择画笔大小:");
        alertDialogBuilder.setSingleChoiceItems(R.array.paintsize, select_paint_size_index, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                select_paint_size_index = which;
                tuyaView.selectPaintSize(which);
                dialog.dismiss();
            }
        });
        alertDialogBuilder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();
            }
        });
        alertDialogBuilder.create().show();
    }
*/
//弹出选择画笔或橡皮擦的对话框
    public void showMoreDialog(View parent){
        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
        alertDialogBuilder.setTitle("选择画笔或橡皮擦:");
        alertDialogBuilder.setSingleChoiceItems(R.array.paintstyle, select_paint_style_index, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                select_paint_style_index = which;
                tuyaView.selectPaintStyle(which);
                dialog.dismiss();
            }
        });
        alertDialogBuilder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dialog.dismiss();
            }
        });
        alertDialogBuilder.create().show();
    }
}

之后应该会有添加了部分新功能的画板,不会太久

自定义view实现涂鸦(画板)功能

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原文地址:http://blog.csdn.net/zhao980919517/article/details/51518044

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