How can I get the fgcolor attribute to work on recent Android versions?

问题

I used to be able to do this:

<string name="foo">white <font fgcolor="#ff6890a5">blue</font></string>

But now it doesn't work any more. It seems to be a bug in the integer parsing code; see https://code.google.com/p/android/issues/detail?id=58192

Problem is, I'm getting customer complaints now; I can't wait for the bug to be fixed.

Does anybody know a work-around, such as using named resources from color.xml or something like that?

ETA: I've discovered fgcolor="blue" still works, but it's the wrong shade of blue. Is there a list of legal color names somewhere? Maybe I could find one that's close enough. It also works if the color is a number without the high bit set, like #7f6890a5, but of course that's too faint to be useful; I need a solid color, not semi-transparent.

ETA: browsing source code shows these colors:

  aqua      0x00FFFF
  black     0x000000
  blue      0x0000FF
  fuchsia   0xFF00FF
  green     0x008000
  grey      0x808080
  lime      0x00FF00
  maroon    0x800000
  navy      0x000080
  olive     0x808000
  purple    0x800080
  red       0xFF0000
  silver    0xC0C0C0
  teal      0x008080
  white     0xFFFFFF
  yellow    0xFFFF00

This doesn't fix my problem, but perhaps other people searching on this question could find this information useful.

回答1:

How about we leverage the fact that colors without the high bit set still works and just replace it with the correct colors? So you can have a method like this:

private CharSequence fixSpanColor(CharSequence text) {
    if (text instanceof Spanned) {
        final SpannableString s = new SpannableString(text);
        final ForegroundColorSpan[] spans = s.getSpans(0, s.length(), ForegroundColorSpan.class);
        for (final ForegroundColorSpan oldSpan : spans) {
            final ForegroundColorSpan newSpan = new ForegroundColorSpan(oldSpan.getForegroundColor() | 0xFF000000);
            s.setSpan(newSpan, s.getSpanStart(oldSpan), s.getSpanEnd(oldSpan), s.getSpanFlags(oldSpan));
            s.removeSpan(oldSpan);
        }
        return s;
    } else {
        return text;
    }
}

You will then need to pass any text with the required color accent through this method, the simplest example would be modifying all calls like this:

tv.setText(getText(R.string.foo));

To:

tv.setText(fixSpanColor(getText(R.string.foo)));

Hopefully, depending on how your code is structured, there might already a central place where you can add this extra method call.

回答2:

I have some awful workaround in my client code to manually reset the ForegroundColorSpans to the proper color, but it would be great not to have to do so.

I think the workaround that the issue reporter's talking about is the following:

Define the string as:

<string name="foo">white blue</string>

In your activity:

TextView tv = (TextView) findViewById(R.id.textView1);

SpannableString spannableString = new 
                       SpannableString(getResources().getString(R.string.foo));

ForegroundColorSpan fcs = new 
                       ForegroundColorSpan(getResources().getColor(R.color.bluish));

spannableString.setSpan(fcs, spannableString.toString().indexOf(" ") + 1,
                       spannableString.length(), Spannable.SPAN_INCLUSIVE_INCLUSIVE);

tv.setText(spannableString);

R.color.bluish is defined as <color name="bluish">#ff6890a5</color>.

But, using " " (space) to distinguish and apply the ForegroundColorSpan would only be practical if you have a small number of strings defined.

The following modification might actually be easier for you to carry out:

Define the string as:

<string name="foo_sep_1"><![CDATA[white <font color=\"#6890a5\">blue</font>]]></string>

Or:

<string name="foo_sep_1">white &lt;font color="#6890a5"&gt;blue&lt;/font&gt;</string>

In your activity:

TextView tv2 = (TextView) findViewById(R.id.textView2);

tv2.setText(Html.fromHtml(getResources().getString(R.string.foo_sep_1)));

Be careful about the color code: HTML color codes do not have alpha values (RRGGBB will work, AARRGGBB will not)

Another workaround is using Html.fromHtml(String) directly:

TextView tv3 = (TextView) findViewById(R.id.textView3);

tv3.setText(Html.fromHtml("white <font color='#6890a5'>blue</font>"));

回答3:

Kudos to TWiStErRob who found a solution that doesn't involve code in https://stackoverflow.com/a/11577658/338479. To quote:

for any color above 7fffffff apply the following: <font color="#ff6890a5"> put ff6890a5 into a calculator (optionally convert to decimal first) and flip the sign, then (optionally convert back to hexa) take the last 8 hexadecimal digits and use <font color="-#00976F5B">.

来源：https://stackoverflow.com/questions/18735290/how-can-i-get-the-fgcolor-attribute-to-work-on-recent-android-versions

标签

android

android-resources