我不喜欢每次我想为所有我的应用程序做了很多工作的文本部分着色时都通过代码执行此操作的想法（由于在某些情况下，文本是在运行时使用不同的内联设置的，定义的颜色），所以我创建了自己的颜色MarkableTextView。
这个想法是：
- 从字符串检测XML标签
- 识别并匹配标签名称
- 提取并保存文本的属性和位置
- 删除标签并保留内容
- 遍历属性并应用样式
这是逐步的过程：
首先，我需要一种在给定字符串中查找XML标签的方法，然后Regex完成了窍门。
<([a-zA-Z]+(?:-[a-zA-Z0-9]+)*)(?:\s+([^>]*))?>([^>][^<]*)</\1\s*>
为了使上述内容与XML标签匹配，它必须具有以下条件：
- 有效标签名称，例如
<a> <a > <a-a> <a ..attrs..>但不是< a> <1>
- 闭合标签的名称与相似，
<a></a>但不相似<a></b>
- 任何内容，因为无需设置“无”样式
现在，对于属性，我们将使用此属性。
([a-zA-Z]+)\s*=\s*(['"])\s*([^'"]+?)\s*\2
它具有相同的概念，通常我都不需要走太远，因为如果任何格式出现问题，编译器将负责其余的工作。
现在我们需要一个可以保存提取数据的类：
public class MarkableSheet {
private String attributes;
private String content;
private int outset;
private int ending;
private int offset;
private int contentLength;
public MarkableSheet(String attributes, String content, int outset, int ending, int offset, int contentLength) {
this.attributes = attributes;
this.content = content;
this.outset = outset;
this.ending = ending;
this.offset = offset;
this.contentLength = contentLength;
}
public String getAttributes() {
return attributes;
}
public String getContent() {
return content;
}
public int getOutset() {
return outset;
}
public int getContentLength() {
return contentLength;
}
public int getEnding() {
return ending;
}
public int getOffset() {
return offset;
}
}
在此之前，我们将添加这个我已经使用了很长时间的酷迭代器来循环进行匹配（不记得作者）：
public static Iterable<MatchResult> matches(final Pattern p, final CharSequence input) {
return new Iterable<MatchResult>() {
public Iterator<MatchResult> iterator() {
return new Iterator<MatchResult>() {
// Use a matcher internally.
final Matcher matcher = p.matcher(input);
// Keep a match around that supports any interleaving of hasNext/next calls.
MatchResult pending;
public boolean hasNext() {
// Lazily fill pending, and avoid calling find() multiple times if the
// clients call hasNext() repeatedly before sampling via next().
if (pending == null && matcher.find()) {
pending = matcher.toMatchResult();
}
return pending != null;
}
public MatchResult next() {
// Fill pending if necessary (as when clients call next() without
// checking hasNext()), throw if not possible.
if (!hasNext()) { throw new NoSuchElementException(); }
// Consume pending so next call to hasNext() does a find().
MatchResult next = pending;
pending = null;
return next;
}
/** Required to satisfy the interface, but unsupported. */
public void remove() { throw new UnsupportedOperationException(); }
};
}
};
}
MarkableTextView：
public class MarkableTextView extends AppCompatTextView {
public MarkableTextView(Context context) {
super(context);
}
public MarkableTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public MarkableTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public void setText(CharSequence text, BufferType type) {
// Intercept and process text
text = prepareText(text.toString());
super.setText(text, type);
}
public Spannable Markable;
private Spannable prepareText(String text) {
String parcel = text;
Multimap<String, MarkableSheet> markableSheets = ArrayListMultimap.create();
// Used to correct content position after tossing tags
int totalOffset = 0;
// Iterate through text
for (MatchResult match : matches(Markable.Patterns.XML, parcel)) {
// Get tag name
String tag = match.group(1);
// Match with a defined tag name "case-sensitive"
if (!tag.equals(Markable.Tags.MARKABLE)) {
// Break if no match
break;
}
// Extract data
String attributes = match.group(2);
String content = match.group(3);
int outset = match.start(0);
int ending = match.end(0);
int offset = totalOffset; // offset=0 since no preceded changes happened
int contentLength = match.group(3).length();
// Calculate offset for the next element
totalOffset = (ending - outset) - contentLength;
// Add to markable sheets
MarkableSheet sheet =
new MarkableSheet(attributes, content, outset, ending, offset, contentLength);
markableSheets.put(tag, sheet);
// Toss the tag and keep content
Matcher reMatcher = Markable.Patterns.XML.matcher(parcel);
parcel = reMatcher.replaceFirst(content);
}
// Initialize spannable with the modified text
Markable = new SpannableString(parcel);
// Iterate through markable sheets
for (MarkableSheet sheet : markableSheets.values()) {
// Iterate through attributes
for (MatchResult match : matches(Markable.Patterns.ATTRIBUTES, sheet.getAttributes())) {
String attribute = match.group(1);
String value = match.group(3);
// Apply styles
stylate(attribute,
value,
sheet.getOutset(),
sheet.getOffset(),
sheet.getContentLength());
}
}
return Markable;
}
最后，样式，这是我为这个答案制作的一个非常简单的样式器：
public void stylate(String attribute, String value, int outset, int offset, int length) {
// Correct position
outset -= offset;
length += outset;
if (attribute.equals(Markable.Tags.TEXT_STYLE)) {
if (value.contains(Markable.Tags.BOLD) && value.contains(Markable.Tags.ITALIC)) {
Markable.setSpan(
new StyleSpan(Typeface.BOLD_ITALIC),
outset,
length,
Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
}
else if (value.contains(Markable.Tags.BOLD)) {
Markable.setSpan(
new StyleSpan(Typeface.BOLD),
outset,
length,
Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
}
else if (value.contains(Markable.Tags.ITALIC)) {
Markable.setSpan(
new StyleSpan(Typeface.ITALIC),
outset,
length,
Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
}
if (value.contains(Markable.Tags.UNDERLINE)) {
Markable.setSpan(
new UnderlineSpan(),
outset,
length,
Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
}
}
if (attribute.equals(Markable.Tags.TEXT_COLOR)) {
if (value.equals(Markable.Tags.ATTENTION)) {
Markable.setSpan(
new ForegroundColorSpan(ContextCompat.getColor(
getContext(),
R.color.colorAttention)),
outset,
length,
Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
}
else if (value.equals(Markable.Tags.INTERACTION)) {
Markable.setSpan(
new ForegroundColorSpan(ContextCompat.getColor(
getContext(),
R.color.colorInteraction)),
outset,
length,
Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
}
}
}
这是Markable包含定义的类的样子：
public class Markable {
public static class Patterns {
public static final Pattern XML =
Pattern.compile("<([a-zA-Z]+(?:-[a-zA-Z0-9]+)*)(?:\\s+([^>]*))?>([^>][^<]*)</\\1\\s*>");
public static final Pattern ATTRIBUTES =
Pattern.compile("(\\S+)\\s*=\\s*(['\"])\\s*(.+?)\\s*\\2");
}
public static class Tags {
public static final String MARKABLE = "markable";
public static final String TEXT_STYLE = "textStyle";
public static final String BOLD = "bold";
public static final String ITALIC = "italic";
public static final String UNDERLINE = "underline";
public static final String TEXT_COLOR = "textColor";
public static final String ATTENTION = "attention";
public static final String INTERACTION = "interaction";
}
}
我们现在需要的只是引用一个字符串，基本上它应该看起来像这样：
<string name="markable_string">
<![CDATA[Hello <markable textStyle=\"underline\" textColor=\"interaction\">world</markable>!]]>
</string>
请务必用包装标签CDATA Section和逃生"用\。
我将其作为一种模块化解决方案，以各种方式处理文本的各个部分，而无需在后面填充不必要的代码。
