Why can't use the same Span object to setSpan above twice?

Question

Why can't use the same Span object to setSpan above twice?

SpannableString ss = new SpannableString("aaaaa[1]bbbb[1]cccc[1]");

I need to replace all the [1] with a image. If I use the following code, only the last one is replaced by the image:

etShow = (EditText) findViewById(R.id.show);
SpannableString ss = new SpannableString("aaaaa[1]bbbb[1]cccc[1]");
int[] starts = new int[3];
int[] ends = new int[3];
int h = 0;
int k = 0;
for (int i = 0; i < ss.length(); i++) {
    if (ss.charAt(i) == '[') {
    starts[h] = i;
    h++;
    } else if (ss.charAt(i) == ']') {
    ends[k] = i;
    k++;
    }
    }

Drawable d = getResources().getDrawable(R.drawable.ic_launcher);
        d.setBounds(0, 0, 50, 50);
        ImageSpan im = new ImageSpan(d);

for(int i=0;i<3;i++){
        ss.setSpan(im, starts[i], ends[i]+1, Spannable.SPAN_INCLUSIVE_EXCLUSIVE);   
        }
etShow.getText().insert(0, ss);

If change to the following code， all the [1] are replaced by the image.

Drawable d = getResources().getDrawable(R.drawable.ic_launcher);
        d.setBounds(0, 0, 50, 50);
        ImageSpan im = new ImageSpan(d);
        ImageSpan im1 = new ImageSpan(d);
        ImageSpan im2 = new ImageSpan(d);
        //for(int i=0;i<3;i++){
//      ss.setSpan(im, starts[i], ends[i]+1, Spannable.SPAN_INCLUSIVE_EXCLUSIVE);
        ss.setSpan(im, starts[0], ends[0]+1, Spannable.SPAN_INCLUSIVE_EXCLUSIVE);
        ss.setSpan(im1, starts[1], ends[1]+1, Spannable.SPAN_INCLUSIVE_EXCLUSIVE);
        ss.setSpan(im2, starts[2], ends[2]+1, Spannable.SPAN_INCLUSIVE_EXCLUSIVE);
    //  }

How can explaint this?

Answer 1

I suspect that the span objects wind up as keys of a HashMap, inside the Spanned representation. Hence, reusing the same span object has the effect of replacing its prior use with a new use.