到目前为止,我已经尝试了两件事。
我尝试使用Color.TRANSPARENT作为我的画笔颜色。
我尝试使用与背景相同的颜色-但是-保存图像时,“背景”在被删除的地方显示为黑色。
我的问题是这个:
是否有可用来擦除的“颜色”?本质上,我希望在“擦除”点透明。
这是我的PaintView的类:
class PaintView extends View {
public ArrayList<Point> listOfColors = new ArrayList<Point>();
public static int BRUSH_SIZE = 60;
public static final int DEFAULT_COLOR = Color.RED;
public static final int DEFAULT_BG_COLOR = Color.WHITE;
private static final float TOUCH_TOLERANCE = 4;
private float mX, mY;
private Path mPath;
private Paint mPaint;
private ArrayList<FingerPath> paths = new ArrayList<>();
private int currentColor;
private int backgroundColor = DEFAULT_BG_COLOR;
private int strokeWidth;
private boolean emboss;
private boolean blur;
private boolean doClear = false;
private MaskFilter mEmboss;
private MaskFilter mBlur;
private Bitmap mBitmap;
private Canvas mCanvas;
private Paint mBitmapPaint = new Paint(Paint.DITHER_FLAG);
ArrayList<Point> listOfPoints = new ArrayList<Point>();
public Bitmap passTheCache;
private DisplayMetrics displayMetrics;
public int xwidth, xheight;
public PaintView(Context context) {
this(context, null);
}
public PaintView(Context context, AttributeSet attrs) {
super(context, attrs);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(DEFAULT_COLOR);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setXfermode(null);
mPaint.setAlpha(0xff);
mEmboss = new EmbossMaskFilter(new float[]{1, 1, 1}, 0.4f, 6, 3.5f);
mBlur = new BlurMaskFilter(5, BlurMaskFilter.Blur.NORMAL);
}
public void setColor(int color) {
currentColor = color;
}
public void init(DisplayMetrics metrics) {
int height = metrics.heightPixels;
int width = metrics.widthPixels;
displayMetrics = metrics;
mBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
passTheCache = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
xwidth = width;
xheight = height;
backgroundColor = Color.BLACK;
currentColor = DEFAULT_COLOR;
strokeWidth = BRUSH_SIZE;
}
public void normal() {
emboss = false;
blur = false;
}
public void emboss() {
emboss = true;
blur = false;
}
public void blur() {
emboss = false;
blur = true;
}
public void clear() {
doClear = true;
setBackgroundColor(0x00AAAAAA);
init(displayMetrics);
paths = new ArrayList<FingerPath>();
normal();
invalidate();
Log.d("FILEZ", "cleared...");
}
@Override
protected void onDraw(Canvas canvas) {
canvas.save();
mCanvas.drawColor(0x00AAAAAA);
Log.d("FILEZ", "size: " + paths.size());
for (FingerPath fp : paths) {
mPaint.setColor(fp.color);
mPaint.setStrokeWidth(fp.strokeWidth);
mPaint.setMaskFilter(null);
if (fp.emboss)
mPaint.setMaskFilter(mEmboss);
else if (fp.blur)
mPaint.setMaskFilter(mBlur);
mCanvas.drawPath(fp.path, mPaint);
}
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.restore();
}
private void touchStart(float x, float y) {
mPath = new Path();
FingerPath fp = new FingerPath(currentColor, emboss, blur, strokeWidth, mPath);
paths.add(fp);
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
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;
}
}
private void touchUp() {
mPath.lineTo(mX, mY);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
Point point = new Point((int) x, (int) y);
listOfColors.add(point);
Log.d("OK", "wtf?!");
Log.d("z", "OK:" + point);
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;
}
return true;
}
}