Combining Spannable with String.format()

android, spannable, spannablestring

Solution

Using Spannables like that is a headache -- this is probably the most straightforward way around:

String s = "The cold hand reaches for the %1$s %2$s Ellesse's";
String old = "<font color=\"blue\">old</font>"; 
String tan = "<strike>tan</strike>"; 
String formatted = String.format(s,old,tan); //The cold hand reaches for the <font color="blue">old</font> <strike>tan</strike> Ellesse's

Spannable spannable = Html.fromHtml(formatted);

Problem: this does not put in a `StrikethroughSpan`. To make the `StrikethroughSpan`, we borrow a custom `TagHandler` from this question.

Spannable spannable = Html.fromHtml(text,null,new MyHtmlTagHandler());

MyTagHandler:

public class MyHtmlTagHandler implements Html.TagHandler {
    public void handleTag(boolean opening, String tag, Editable output,
                          XMLReader xmlReader) {
        if (tag.equalsIgnoreCase("strike") || tag.equals("s")) {
            processStrike(opening, output);
        }
    }
    private void processStrike(boolean opening, Editable output) {
        int len = output.length();
        if (opening) {
            output.setSpan(new StrikethroughSpan(), len, len, Spannable.SPAN_MARK_MARK);
        } else {
            Object obj = getLast(output, StrikethroughSpan.class);
            int where = output.getSpanStart(obj);
            output.removeSpan(obj);
            if (where != len) {
                output.setSpan(new StrikethroughSpan(), where, len, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
            }
        }
    }

    private Object getLast(Editable text, Class kind) {
        Object[] objs = text.getSpans(0, text.length(), kind);
        if (objs.length == 0) {
            return null;
        } else {
            for (int i = objs.length; i > 0; i--) {
                if (text.getSpanFlags(objs[i - 1]) == Spannable.SPAN_MARK_MARK) {
                    return objs[i - 1];
                }
            }
            return null;
        }
    }
}

Problem

Suppose you have the following string: ``` String s = "The cold hand reaches for the %1$s %2$s Ellesse's"; String old = "old"; String tan = "tan"; String formatted = String.format(s,old,tan); //"The cold hand reaches for the old tan Ellesse's" ``` Suppose you want to end up with this string, but also have a particular `Span` set for any word replaced by `String.format`. For instance, we also want to do the following: ``` Spannable spannable = new SpannableString(formatted); spannable.setSpan(new StrikethroughSpan(), oldStart, oldStart+old.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); spannable.setSpan(new ForegroundColorSpan(Color.BLUE), tanStart, tanStart+tan.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); ``` Is there a robust way of getting to know the start indices of `old` and `tan`? Note that just searching for 'old' returns the 'old' in 'cold', so that won't work. What will work, I guess, is searching for `%[0-9]$s` beforehand, and calculating the offsets to account for the replacements in `String.format`. This seems like a headache though, I suspect there might be a method like `String.format` that is more informative about the specifics of its formatting. Well, is there?

Original source

Related problems