在android中撤消自定义图像视图上的绘图[已关闭]

我正在开发绘图应用程序,到目前为止,我能够在图像上绘制线条,问题是我发现它无法在自定义图像视图中集成撤消操作。

我应用了“逐个存储绘制路径,并在onDraw短语上绘制”的逻辑,但代码中似乎有一些缺失/缺陷。

如果您想了解更多有关代码的详细信息,欢迎提出任何问题。截图是我的应用程序的样子(在图像上绘制)

谢谢你的帮助。

在 主要活动 :

// set image

    bitmap = downScale(view.getTag().toString(),1280,1024);
    altered_bitmap = Bitmap.createBitmap(bitmap.getWidth(),bitmap.getHeight(), bitmap.getConfig());
    draw_view.setNewImage(altered_bitmap,bitmap);

undo.setOnClickListener(new OnClickListener(){
            @Override
            public void onClick(View arg0) {
                if (pencil.getVisibility() == View.VISIBLE || pen.getVisibility() == View.VISIBLE) {
                    draw_view.onClickUndo();
                }
            }
        });

在 自定义图像视图 :

private ArrayList<Path> paths = new ArrayList<Path>();
    private Path mPath;

  public ScaleImageView(Context context) {
            super(context);
            sharedConstructing(context);
        }

    public void sharedConstructing(Context context) {
            super.setClickable(true);
            this.context = context;

            mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
            matrix = new Matrix();
            m = new float[9];
            setImageMatrix(matrix);
            setScaleType(ScaleType.MATRIX);

            paint = new Paint();

            paint.setAntiAlias(true);
            paint.setStrokeWidth(width);
            paint.setColor(color);
            paint.setStyle(Paint.Style.STROKE);
            paint.setStrokeJoin(Paint.Join.ROUND);
            paint.setStrokeCap(Paint.Cap.ROUND);
            paint.setAlpha(alpha);


            drawListener = new OnTouchListener() {
                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    if (getDrawable() != null) {
                        int action = event.getAction();
                        switch (action) {
                            case MotionEvent.ACTION_DOWN:
                                downx = getPointerCoords(event)[0];// event.getX();
                                downy = getPointerCoords(event)[1];// event.getY();
                                break;
                            case MotionEvent.ACTION_MOVE:
                                upx = getPointerCoords(event)[0];// event.getX();
                                upy = getPointerCoords(event)[1];// event.getY();
                                canvas.drawLine(downx, downy, upx, upy, paint);
                                mPath = new Path();
                                paths.add(mPath);
                                invalidate();
                                downx = upx;
                                downy = upy;
                                break;
                            case MotionEvent.ACTION_UP:
                                upx = getPointerCoords(event)[0];// event.getX();
                                upy = getPointerCoords(event)[1];// event.getY();
                                canvas.drawLine(downx, downy, upx, upy, paint);
                                mPath = new Path();
                                paths.add(mPath);
                                invalidate();
                                break;
                            case MotionEvent.ACTION_CANCEL:
                                break;
                            default:
                                break;
                        }
                    }
                    return true;
                }
            };

            setOnTouchListener(drawListener);
        }

        //draw view start
        public void setNewImage(Bitmap alteredBitmap, Bitmap bmp) {
            canvas = new Canvas(alteredBitmap);
            matrix_draw = new Matrix();
            canvas.drawBitmap(bmp, matrix_draw, paint);
            setImageBitmap(alteredBitmap);  
            mPath = new Path();
            paths.add(mPath);
        }

        public void setBrushColor(int color) {
            this.color = color;
            paint.setColor(color);
            paint.setAlpha(alpha);
        }

        public void setAlpha(int alpha) {
            this.alpha = alpha;
            paint.setAlpha(alpha);
        }

        public void setWidth(float width) {
            this.width = width;
            paint.setStrokeWidth(width);
        }

        final float[] getPointerCoords(MotionEvent e) {
            final int index = e.getActionIndex();
            final float[] coords = new float[] { e.getX(index), e.getY(index) };
            Matrix matrix = new Matrix();
            getImageMatrix().invert(matrix);
            matrix.postTranslate(getScrollX(), getScrollY());
            matrix.mapPoints(coords);
            return coords;
        }

        public void setIsScale() {
            isScale = !isScale;
            setOnTouchListener(isScale ? zoomListener : drawListener);
        }

    @Override
    protected void onDraw(Canvas canvas) {  
        for (Path p : paths){
            canvas.drawPath(p, paint_line);
        }
    }

    public void onClickUndo () {
        if (paths.size()>0){
            paths.remove(paths.size()-1);
            invalidate();
        }
    }
    //draw view end

更新:测试结果

测试一段时间后,发现应用程序运行,但所选图像未在自定义图像视图中绘制,如下所示:

如果你有空闲时间,我已经上传了项目(<1 mb), 这是一个小型绘图工具,首先将包含一些图像的文件夹复制到设备中的文件夹“HistoryTool”

例如,路径如下:

sd card root/ HistoryTool/ folder1 / a.jpg 

,然后就可以在上面绘制了,仅此而已,但现在撤消操作无法运行,需要修复。

https://drive.google.com/file/d/0B9mELZtUJp0LLVh0b1Q0a3VTcG8/view?usp=sharing

谢谢