Code for drawing in any View with finger

To draw using finger in any LinearLayout, set the padding of the LinearLayout​ to 0 and add following code in onCreate event using add source directly block.

dv = new DrawingView(this);linear2.addView(dv); mPaint = new Paint(); mPaint.setAntiAlias(true); mPaint.setDither(true); mPaint.setColor(Color.GREEN); mPaint.setStyle(Paint.Style.STROKE); mPaint.setStrokeJoin(Paint.Join.ROUND); mPaint.setStrokeCap(Paint.Cap.ROUND); mPaint.setStrokeWidth(12); }

DrawingView dv; private Paint mPaint;
private Canvas mCanvas;

public class DrawingView extends View { public int width;
public int height;
private Bitmap mBitmap;
private Path mPath;
private Paint mBitmapPaint;
Context context; private Paint circlePaint; private Path circlePath;

public DrawingView(Context c) { super(c); context=c; mPath = new Path(); mBitmapPaint = new Paint(Paint.DITHER_FLAG); circlePaint = new Paint(); circlePath = new Path(); circlePaint.setAntiAlias(true); circlePaint.setColor(Color.BLUE); circlePaint.setStyle(Paint.Style.STROKE); circlePaint.setStrokeJoin(Paint.Join.MITER); circlePaint.setStrokeWidth(4f); }

@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) { super.onDraw(canvas); canvas.drawBitmap( mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath( mPath, mPaint); canvas.drawPath( circlePath, circlePaint);
invalidate(); }

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; circlePath.reset(); circlePath.addCircle(mX, mY, 30, Path.Direction.CW); } }
private void touch_up() { mPath.lineTo(mX, mY); circlePath.reset();
mCanvas.drawPath(mPath, mPaint);
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; }

Note that in this code linear2 is the ID of the LinearLayout in which Drawing View is added. Change it as per the ID of your LinearLayout.

To share the image drawn in LinearLayout using finger, add following code in onCreate event right after the above code:

}
private void storeImage(Bitmap image) { java.io.File pictureFile = new java.io.File(getExternalCacheDir() + "/image.jpg");
if (pictureFile == null) { Log.d("MainActivity", "Error creating media file, check storage permissions: ");
return; } try {
java.io.FileOutputStream fos = new java.io.FileOutputStream(pictureFile); image.compress(Bitmap.CompressFormat.PNG, 90, fos);
fos.close(); } catch (java.io.FileNotFoundException e) { Log.d("MainActivity", "File not found: " + e.getMessage()); } catch (java.io.IOException e) { Log.d("MainActivity", "Error accessing file: " + e.getMessage());
}

Intent iten = new Intent(android.content.Intent.ACTION_SEND);
iten.setType("*/*");
iten.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(new java.io.File(getExternalCacheDir() + "/image.jpg")));
startActivity(Intent.createChooser(iten, "Send image"));
}

private Bitmap getBitmapFromView(View view) { Bitmap returnedBitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(),Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(returnedBitmap);
android.graphics.drawable.Drawable bgDrawable =view.getBackground();
if (bgDrawable!=null) { bgDrawable.draw(canvas); } else{ canvas.drawColor(Color.WHITE); }
view.draw(canvas);
return returnedBitmap;

After this add a Button in VIEW area, which will act as share button, and onButtonClick event, add following code:

storeImage(getBitmapFromView(linear2));

In this way you can draw with your finger and share the image.

In order to clear the drawing, add a new Button in VIEW area. In LOGIC area, in onClick event for that button, use add source directly block to put following code:

mCanvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR);


Example of an app which can be used to draw over a pic from gallery, and then share it.