Faster/Less Overhead Approach to ClickableSpans and Using Cursors?

Question

I'm feeding data between databases in my Android app. One database's information appears in a textview as clickable spans. A cursor reorders all spans when a new span is created before they are all re-appended to the textview.

This functionality works, but iterating through a cursor every time the data changes over a short period of time is noticeably slow once the database has around 50 or more rows.

Is there a way to implement an approach that only needs to look at the new row to add it in its proper place, instead of iterating through every row in a cursor every single time a new span is created? Similarly, is there a way to remove the span without having to reload the entire textview?

Code for preparing data for textview consisting of clickableSpans:

        Cursor cursor = dbHelper.fetchAllTT3Values();

        do {
            String value = cursor.getString(cursor.getColumnIndex("mainValues"));
            doClickSpanForString(tv1, value, cursor.getInt(3));

        } while (cursor.moveToNext());

        cursor.close();

(Note: the dbHelper.fetchAllTT3Values() function orders data by a column of integers, so this rearranges what is appended in the function below.)

Code for clickable spans tagged with data:

public void doClickSpanForString(TextView txtSpan, String valtag, Integer valordtag) {
        spanText = new SpannableString(valtag+" ");
        MyClickableSpan a = new MyClickableSpan(valtag);
        a.setTag1(valtag);
        a.setTag2(valordtag);
        spanText.setSpan(a, 0, valtag.length(), 0);
        txtSpan.append(spanText);

    }

private class MyClickableSpan extends ClickableSpan {

        private String mtag1;
        private int mtag2;

        void setTag1(String tag) {
            mtag1 = tag;
        }
        String getTag1() {
            return mtag1;
        }
        void setTag2(Integer tag) {
            mtag2 = tag;
        }
        int getTag2() {
            return mtag2;
        }

        MyClickableSpan(String string) {
            super();
        }
        public void onClick(View tv) {
            //tv.performLongClick();


            setstr4val(getTag1());
            setint4valord(getTag2());

        }
}

Boom100100 · Answer 1 · 2018-05-10T19:16:49.567

Edit:

I ended up not using the method below by querying data only once from the database during use of that database's data. It's way faster, but after about a thousand pieces of data are added to the textview, it's still noticeably slow. Either attaching a large spannablestringbuilder to textview or updating data beforehand via loops is contributing to the slowness. I think removing the loops is the only solution. But that won't make attaching data to textview any faster, if that attachment is a bottleneck. WHAT FOLLOWS IS AN OLD, INSUFFICIENT SOLUTION.

    sb = new SpannableStringBuilder("");
    do {

        String value = cursor.getString(cursor.getColumnIndex("mainValues"));
        sb.append(doClickSpanForString(value, cursor.getInt(3)));

    } while (cursor.moveToNext());

    tv1.setText(sb);

Changing the function doClickSpanForString to not act on the textView at every iteration of the loop made this code much more efficient. But it's still slow.

Faster/Less Overhead Approach to ClickableSpans and Using Cursors?

1 Answers1