How To Draw A Flower In Android Each Petal By Petal

Question

In android I would like to draw flower by adding each petal from a center point. I used setRotation on the image view but the center point is different for each petal. (I mean the center point from the flower) Can anybody look at my code and suggest me correction? Thanks.

   int angle=0;
   int ypos=500;
   int xpos=500;

   RelativeLayout layout = (RelativeLayout)findViewById(R.id.ln1);

   for(int i=0;i<10;i++)
   {

      ImageView image = new ImageView(this);
      image.setLayoutParams(new android.view.ViewGroup.LayoutParams(150,400));
      image.setX(xpos);
      image.setY(ypos);
      image.setPadding(-7,-30,-10,0);
      image.setPivotX(1.0f);
      image.setScaleX(1.5f);
      image.setScaleY(1.5f);

      image.setImageResource(R.drawable.petal);
      image.setRotation(image.getRotation() + angle);
      angle=angle+36;
      layout.addView(image);
   }

Image I get is this

Answer 1

When you rotate the image, the rotation is done with the top left corner of the image, not the center of the rotated image.

Below image might illustrate this. The black square represents your image. The lefthand site shows the situation you have now. The righthand side shows the situation you want.

Before rotating, you should subtract half the width from the x position, and add half the height from the y position. Then you should get the desired image.

As user Ralf Renz pointed out in their comment, you could also simply start with an angle of -36. This is a useful workaround.