Most probably you've read up on SpannableStringBuilder
, which allows you to add color to the text in your TextView's content. Check out the code below:
SpannableStringBuilder ssb = new SpannableStringBuilder(<your text>);
ForegroundColorSpan fcs = new ForegroundColorSpan(Color.rgb(255, 0, 0));
ssb.setSpan(fcs, 0, ssb.length, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
textView.setText(ssb);
The code above will work in most cases, however what you want is to have different alternating colors on a single TextView. Then you should do the following:
String text = your_text + text_from_database;
SpannableStringBuilder ssb = new SpannableStringBuilder(text);
ForegroundColorSpan fcs = new ForegroundColorSpan(Color.rgb(255, 0, 0));
ForegroundColorSpan fcs2 = new ForegroundColorSpan(Color.rgb(0, 255 0));
ssb.setSpan(fcs, 0, your_text, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
ssb.setSpan(fcs2, your_text.length(), ssb.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
textView.setText(ssb);
The above code will now work, but you'll notice that if you add another text your_another_text
and want to use the previous fcs
instance for a second time, the previously colored your_text
will now lose its formatting (color). This time you'll need to create another ForegroundColorSpan fcs3 to format the third part of the SpannableStringBuilder. The key here is to use a character style in a setSpan
method only once. See below:
String testTest = "abcdefgh";
String testTest2 = "ijklmnop";
String testTest3 = "qrstuvwxyz";
SpannableStringBuilder ssb = new SpannableStringBuilder(testTest+testTest2+testTest3);
ForegroundColorSpan fcs = new ForegroundColorSpan(Color.rgb(255, 0, 0));
ForegroundColorSpan fcs2 = new ForegroundColorSpan(Color.rgb(0, 255, 0));
ForegroundColorSpan fcs3 = new ForegroundColorSpan(Color.rgb(255, 0, 0));
ssb.setSpan(fcs, 0, testTest.length(), Spannable.SPAN_INCLUSIVE_INCLUSIVE);
ssb.setSpan(fcs2, testTest.length(), (testTest+testTest2).length(), Spannable.SPAN_INCLUSIVE_INCLUSIVE);
ssb.setSpan(fcs3, (testTest+testTest2).length(), ssb.length(), Spannable.SPAN_INCLUSIVE_INCLUSIVE);
test.setText(ssb);
This method is good if you know you have a fixed number of String elements in your SpannableStringBuilder. If you have wish to have a TextView of dynamic length and number of elements, you need to do this in a different approach. What worked for me was to convert each string element into a SpannableString, use setSpan
, and append
it to the TextView. This is useful if you're using a loop to build your TextView.
TextView test = (TextView)findViewById(R.id.test);
String testTest = "abcdefgh";
String testTest2 = "ijklmnop";
String testTest3 = "qrstuvwxyz";
SpannableString ssb = new SpannableString(testTest);
ForegroundColorSpan fcs = new ForegroundColorSpan(Color.rgb(255, 0, 0));
ForegroundColorSpan fcs2 = new ForegroundColorSpan(Color.rgb(0, 255, 0));
ForegroundColorSpan fcs3 = new ForegroundColorSpan(Color.rgb(255, 0, 0));
ssb.setSpan(fcs, 0, ssb.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
test.setText(ssb);
SpannableString ssb2 = new SpannableString(testTest2);
ssb2.setSpan(fcs2, 0, ssb2.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
test.append(ssb2);
SpannableString ssb3 = new SpannableString(testTest3);
ssb3.setSpan(fcs3, 0, ssb3.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
test.append(ssb3);