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这是绘图和撤消的代码，但无法加入擦除。

它是绘图 + 擦除或绘图 + 撤消，但不能是其中三个。

public class Drawing extends View {
private Paint mPaint, mBitmapPaint;
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;

private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;

private int color, size, state;

private ArrayList<Path> paths = new ArrayList<Path>();
private ArrayList<Path> undonePaths = new ArrayList<Path>();
private ArrayList<Integer> colors = new ArrayList<Integer>();
private ArrayList<Integer> sizes = new ArrayList<Integer>();

public Drawing(Context c) {
    super(c);
}

public Drawing(Context c,int width, int height, int size, int color, int state) {
    super(c);

    mBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    mCanvas = new Canvas(mBitmap);
    mPath = new Path();

    mPaint = new Paint();
    mPaint.setAntiAlias(true);
    mPaint.setDither(true);
    mPaint.setStyle(Paint.Style.STROKE);
    mPaint.setStrokeJoin(Paint.Join.ROUND);
    mPaint.setStrokeCap(Paint.Cap.ROUND);

//      mBitmapPaint = new Paint(Paint.DITHER_FLAG);
//      mBitmapPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC));

    setColor(color);
    setSize(size);
    setState(state);
}

@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.drawColor(Color.TRANSPARENT);
//      canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
//
//      if (state == 0)
//          mBitmap.eraseColor(Color.TRANSPARENT);

    for (int i = 0; i < paths.size(); i++) {
        mPaint.setColor(colors.get(i));
        mPaint.setStrokeWidth(sizes.get(i));
        canvas.drawPath(paths.get(i), mPaint);
    }
    mPaint.setColor(color);
    mPaint.setStrokeWidth(size);
    canvas.drawPath(mPath, mPaint);

}

public void setColor(int color) {
    this.color = color;
}

public void setSize(int size) {
    this.size = size;
}

public void setState(int state) {
    this.state = state;
    // if (state == 0)
    // mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
    // else
    // mPaint.setXfermode(null);
}

public void onClickUndo() {
    if (paths.size() > 0) {
        undonePaths.add(paths.remove(paths.size() - 1));
        sizes.remove(sizes.size() - 1);
        colors.remove(colors.size() - 1);
        invalidate();
    }
}

private void touch_start(float x, float y) {
    undonePaths.clear();
    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() {
    mPath.lineTo(mX, mY);
    mCanvas.drawPath(mPath, mPaint);

    colors.add(color);
    sizes.add(size);
    paths.add(mPath);
    mPath = new Path();
}

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

    switch (event.getAction()) {
    case MotionEvent.ACTION_DOWN:
        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;
}
}

我试图使颜色透明，但这没有意义，因为不改变像素而是创建新路径。

4

1 回答 1

0

下面可用于绘制擦除、浮雕、保存到画廊、模糊。您可以使用代码添加撤消和重做功能。下面的代码工作正常。您可以从 grapics 文件夹中的 api demos 下的 adk 的示例文件夹中检查 FingerPaint.java。

在 android 中为触摸绘制创建喷雾效果。此链接将帮助您通过喷涂点创建喷涂效果。

public class FingerPaintActivity extends GraphicsActivity
    implements ColorPickerDialog.OnColorChangedListener {

    private Paint       mPaint;
    private MaskFilter  mEmboss;
    private MaskFilter  mBlur;
    Button b;
    Dialog dialog;
    static MyView mv;
    File f;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    LinearLayout ll = (LinearLayout) findViewById(R.id.ll);
    mv= new MyView(this);
    mv.setDrawingCacheEnabled(true);
    ll.addView(mv);
    b= (Button) findViewById(R.id.button1);
    b.setOnClickListener(new OnClickListener()
    {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            final CharSequence[] items = {"Pick Color", "Emboss", "Blur","Erase","SaveToGallery"};

            AlertDialog.Builder builder = new AlertDialog.Builder(FingerPaintActivity.this);
            builder.setTitle("Options");
            builder.setItems(items, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int item) {

                       if(item==0)
                       {
                           new ColorPickerDialog(FingerPaintActivity.this, FingerPaintActivity.this, mPaint.getColor()).show();
                       }
                       if(item==1)
                       {
                           if (mPaint.getMaskFilter() != mEmboss) {
                                mPaint.setMaskFilter(mEmboss);
                            } else {
                                mPaint.setMaskFilter(null);
                            }

                       }
                       if(item==2)
                       {
                           if (mPaint.getMaskFilter() != mBlur) {
                                mPaint.setMaskFilter(mBlur);
                            } else {
                                mPaint.setMaskFilter(null);
                            }
                       }
                       if(item==3)
                       {
                           mPaint.setXfermode(new PorterDuffXfermode(
                                   PorterDuff.Mode.CLEAR));
                       }
                       if(item==4)
                       {

                          saveImage();
                       }
                   }
               });


            builder.show();
        }


    });
    mPaint = new Paint();
    mPaint.setAntiAlias(true);
    mPaint.setDither(true);
    mPaint.setColor(0xFFFF0000);
    mPaint.setStyle(Paint.Style.STROKE);
    mPaint.setStrokeJoin(Paint.Join.ROUND);
    mPaint.setStrokeCap(Paint.Cap.ROUND);
    mPaint.setStrokeWidth(20);

    mEmboss = new EmbossMaskFilter(new float[] { 1, 1, 1 },
                                   0.4f, 6, 3.5f);

    mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL);
}


public void colorChanged(int color) {
    mPaint.setColor(color);
}


public class MyView extends View {

    private static final float MINP = 0.25f;
    private static final float MAXP = 0.75f;

    private Bitmap  mBitmap;
    private Canvas  mCanvas;
    private Path    mPath;
    private Paint   mBitmapPaint;
    Context mcontext;

    public MyView(Context c) {
        super(c);
        mcontext=c;
        mPath = new Path();
        mBitmapPaint = new Paint();
        mBitmapPaint.setColor(Color.RED);
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
        mCanvas = new Canvas(mBitmap);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        canvas.drawColor(0xFFAAAAAA);
        Display display = ( (Activity) mcontext).getWindowManager().getDefaultDisplay();  
        float w = display.getWidth(); 
        float h = display.getHeight();
        canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
        canvas.drawLine(0, 0, w, 0,mBitmapPaint);
        canvas.drawLine(0, 0, 0, h,mBitmapPaint);
        canvas.drawLine(w,h,w,0,mBitmapPaint);
        canvas.drawLine(w, h, 0,h , mBitmapPaint);
        canvas.drawPath(mPath, mPaint);
    }

    private float mX, mY;
    private static final float TOUCH_TOLERANCE = 4;

    private void touch_start(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() {
        mPath.lineTo(mX, mY);
        // commit the path to our offscreen
        mCanvas.drawPath(mPath, mPaint);
        mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SCREEN));
        // kill this so we don't double draw
        mPath.reset();
    }

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

        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                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;
    }
}
    public void saveImage()
    {
    AlertDialog.Builder editalert = new AlertDialog.Builder(FingerPaintActivity.this);
    editalert.setTitle("Please Enter the name with which you want to Save");
    final EditText input = new EditText(FingerPaintActivity.this);
    LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
            LinearLayout.LayoutParams.FILL_PARENT,
            LinearLayout.LayoutParams.FILL_PARENT);
    input.setLayoutParams(lp);
    editalert.setView(input);
    editalert.setPositiveButton("OK", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int whichButton) {
        mv.setDrawingCacheEnabled(true);
        String name= input.getText().toString();
        Bitmap bitmap = mv.getDrawingCache();
     String root = Environment.getExternalStorageDirectory().toString();
        File myDir = new File(root + "/MapleBearDraw");    
        myDir.mkdirs();
        File file = new File (myDir, name+".jpg");
        if (file.exists ()) file.delete ();         
        try 
        {
            if(!file.exists())
        {
            file.createNewFile();
        }
            FileOutputStream ostream = new FileOutputStream(file);
            bitmap.compress(CompressFormat.JPEG, 50, ostream);
            ostream.flush();
            ostream.close();  
            mv.invalidate();                            
        } 
        catch (Exception e) 
        {
            e.printStackTrace();
        }finally
        {

            mv.setDrawingCacheEnabled(false);                           
        }
        }
    });

    editalert.show();   
 }
private static final int COLOR_MENU_ID = Menu.FIRST;
private static final int EMBOSS_MENU_ID = Menu.FIRST + 1;
private static final int BLUR_MENU_ID = Menu.FIRST + 2;
private static final int ERASE_MENU_ID = Menu.FIRST + 3;
private static final int SRCATOP_MENU_ID = Menu.FIRST + 4;


public boolean onCreateOptionsMenu(Menu menu) {
    super.onCreateOptionsMenu(menu);

    menu.add(0, COLOR_MENU_ID, 0, "Color").setShortcut('3', 'c');
    menu.add(0, EMBOSS_MENU_ID, 0, "Emboss").setShortcut('4', 's');
    menu.add(0, BLUR_MENU_ID, 0, "Blur").setShortcut('5', 'z');
    menu.add(0, ERASE_MENU_ID, 0, "Erase").setShortcut('5', 'z');
    menu.add(0, SRCATOP_MENU_ID, 0, "SrcATop").setShortcut('5', 'z');

    /****   Is this the mechanism to extend with filter effects?
    Intent intent = new Intent(null, getIntent().getData());
    intent.addCategory(Intent.CATEGORY_ALTERNATIVE);
    menu.addIntentOptions(
                          Menu.ALTERNATIVE, 0,
                          new ComponentName(this, NotesList.class),
                          null, intent, 0, null);
    *****/
    return true;
}

@Override
public boolean onPrepareOptionsMenu(Menu menu) {
    super.onPrepareOptionsMenu(menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    mPaint.setXfermode(null);
    mPaint.setAlpha(0xFF);

    switch (item.getItemId()) {
        case COLOR_MENU_ID:
            new ColorPickerDialog(FingerPaintActivity.this, this, mPaint.getColor()).show();
            return true;
        case EMBOSS_MENU_ID:
            if (mPaint.getMaskFilter() != mEmboss) {
                mPaint.setMaskFilter(mEmboss);
            } else {
                mPaint.setMaskFilter(null);
            }
            return true;
        case BLUR_MENU_ID:
            if (mPaint.getMaskFilter() != mBlur) {
                mPaint.setMaskFilter(mBlur);
            } else {
                mPaint.setMaskFilter(null);
            }
            return true;
        case ERASE_MENU_ID:
            mPaint.setXfermode(new PorterDuffXfermode(
                                                    PorterDuff.Mode.CLEAR));
            return true;
        case SRCATOP_MENU_ID:
            mPaint.setXfermode(new PorterDuffXfermode(
                                                PorterDuff.Mode.SRC_ATOP));
            mPaint.setAlpha(0x80);
            return true;
    }
    return super.onOptionsItemSelected(item);
}

}
于 2013-03-19T06:35:47.070 回答