I know I'm a bit late for the party but I think this is going to help future visitors out.
You might wanna set partial text colors on the layout XML instead of using Java code, so based on previous answers on this thread I've created a small class that does the trick.
1 - First let's create our component
package yourpackagehere.component;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Color;
import android.text.Spannable;
import android.text.SpannableString;
import android.text.style.ForegroundColorSpan;
import android.util.AttributeSet;
import yourpackagehere.R;
public class FontSpannableTextView extends TextView {
public FontSpannableTextView(Context context) {
super(context);
}
public FontSpannableTextView(Context context, AttributeSet attrs) {
super(context, attrs);
setColorPartialString(context, attrs);
}
public FontSpannableTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
setColorPartialString(context, attrs);
}
private void setColorPartialString(Context context, AttributeSet attrs) {
if (isInEditMode()) {
return;
}
String partialText = null;
int partialTextColor = Integer.MIN_VALUE;
if (attrs != null) {
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.FontSpannableTextView);
for (int i = 0; i < a.getIndexCount(); i++) {
int attr = a.getIndex(i);
switch (attr) {
case R.styleable.FontSpannableTextView_fontspannabletextview_partialText:
partialText = a.getString(attr);
break;
case R.styleable.FontSpannableTextView_fontspannabletextview_partialTextColor:
partialTextColor = a.getColor(attr, Color.BLACK);
break;
}
}
a.recycle();
}
if (partialText != null && partialTextColor != Integer.MIN_VALUE) {
String wholeText = getText().toString();
Spannable spannable = new SpannableString(wholeText);
spannable.setSpan(new ForegroundColorSpan(partialTextColor),
wholeText.indexOf(partialText),
wholeText.indexOf(partialText) + partialText.length(),
Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
setText(spannable);
} else {
Log.e("YOURTAGHERE","You must provide both partialText and partialTextColor values");
}
}
}
2 - on attrs.xml
<?xml version="1.0" encoding="utf-8"?>
<resources>
<declare-styleable name="FontSpannableTextView">
<attr name="fontspannabletextview_partialText" format="string" />
<attr name="fontspannabletextview_partialTextColor" format="color" />
</declare-styleable>
</resources>
3 - Let's use it in our test layout
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto">
<yourpackagehere.component.FontSpannableTextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/hello_world" <!-- Hello world! -->
android:layout_margin="25dp"
app:fontspannabletextview_partialText="@string/world" <!-- world! -->
app:fontspannabletextview_partialTextColor="@color/tutorial_yellow"
android:textSize="40sp"
/>
</LinearLayout>
Example:
