package org.droidplanner.services.android.impl.utils;
import android.graphics.Typeface;
import android.text.Spannable;
import android.text.SpannableStringBuilder;
import android.text.Spanned;
import android.text.style.ForegroundColorSpan;
import android.text.style.StyleSpan;
/**
* Contains text, and formatting related functions.
*/
public class TextUtils {
// Not instantiable
private TextUtils() {
}
/**
* Returns a CharSequence that concatenates the specified array of
* CharSequence objects and then applies a list of zero or more tags to the
* entire range.
*
* @param content
* an array of character sequences to apply a style to
* @param tags
* the styled span objects to apply to the content such as
* android.text.style.StyleSpan
*
*/
private static CharSequence apply(CharSequence[] content, Object... tags) {
SpannableStringBuilder text = new SpannableStringBuilder();
openTags(text, tags);
for (CharSequence item : content) {
text.append(item);
}
closeTags(text, tags);
return text;
}
/**
* Iterates over an array of tags and applies them to the beginning of the
* specified Spannable object so that future text appended to the text will
* have the styling applied to it. Do not call this method directly.
*/
private static void openTags(Spannable text, Object[] tags) {
for (Object tag : tags) {
text.setSpan(tag, 0, 0, Spanned.SPAN_MARK_MARK);
}
}
/**
* "Closes" the specified tags on a Spannable by updating the spans to be
* endpoint-exclusive so that future text appended to the end will not take
* on the same styling. Do not call this method directly.
*/
private static void closeTags(Spannable text, Object[] tags) {
int len = text.length();
for (Object tag : tags) {
if (len > 0) {
text.setSpan(tag, 0, len, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
} else {
text.removeSpan(tag);
}
}
}
/**
* Returns a CharSequence that applies boldface to the concatenation of the
* specified CharSequence objects.
*/
public static CharSequence bold(CharSequence... content) {
return apply(content, new StyleSpan(Typeface.BOLD));
}
/**
* Returns a CharSequence that applies italics to the concatenation of the
* specified CharSequence objects.
*/
public static CharSequence italic(CharSequence... content) {
return apply(content, new StyleSpan(Typeface.ITALIC));
}
/**
* Returns a CharSequence that removes applied type faces.
*/
public static CharSequence normal(CharSequence... content) {
return apply(content, new StyleSpan(Typeface.NORMAL));
}
/**
* Returns a CharSequence that applies a foreground color to the
* concatenation of the specified CharSequence objects.
*/
public static CharSequence color(int color, CharSequence... content) {
return apply(content, new ForegroundColorSpan(color));
}
}