[Android]為TextView提供雙色文本配置的小工具ColorPhrase

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本文連結http://blog.csdn.net/jan_s/article/details/51338944，轉載請留言。

在安卓開發過程中，經常會看到文本中有重點的欄位是需要換色的，為了表現其特殊性。這個時候大多數人都會用比較簡單的方式就是再New 一個TextView出來，顯然很快速，然而這樣做無疑是給布局繪製添加麻煩，這裡簡單提供一個工具ColorPhrase類，幫你解決這一的麻煩。

先看demo

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使用方式：

1.MainActivity.java

public class MainActivity extends Activity {private EditText editText;private TextView textView;private Button button;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);editText = (EditText) findViewById(R.id.editText1);textView = (TextView) findViewById(R.id.textView1);button = (Button) findViewById(R.id.button1);button.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {//這裡是使用方法：將主要換色的文本用“{}”區分出來，然後對其文本風格顏色做處理，這就是ColorPhrase的工作了。String pattern = editText.getText().toString();CharSequence chars = ColorPhrase.from(pattern).withSeparator("{}").innerColor(getResources().getColor(R.color.in_color)).outerColor(getResources().getColor(R.color.out_color)).format();textView.setText(chars);}});}}

2.ColorPhrase.java-這是主要的功能實作類別，拷貝到項目中即可。

public class ColorPhrase {/** The unmodified original pattern. */private final CharSequence pattern;/** Cached result after replacing all keys with corresponding values. */private CharSequence formatted;/** * The constructor parses the original pattern into this doubly-linked list * of tokens. */private Token head;/** When parsing, this is the current character. */private char curChar;private String separator;// default "{}"private int curCharIndex;private int outerColor;// color that outside the separators,default 0xFF666666private int innerColor;// color that between the separators,default 0xFFA6454A/** Indicates parsing is complete. */private static final int EOF = 0;/** * Entry point into this API. *  * @throws IllegalArgumentException *             if pattern contains any syntax errors. */@TargetApi(Build.VERSION_CODES.HONEYCOMB)public static ColorPhrase from(Fragment f, int patternResourceId) {return from(f.getResources(), patternResourceId);}/** * Entry point into this API. *  * @throws IllegalArgumentException *             if pattern contains any syntax errors. */public static ColorPhrase from(View v, int patternResourceId) {return from(v.getResources(), patternResourceId);}/** * Entry point into this API. *  * @throws IllegalArgumentException *             if pattern contains any syntax errors. */public static ColorPhrase from(Context c, int patternResourceId) {return from(c.getResources(), patternResourceId);}/** * Entry point into this API. *  * @throws IllegalArgumentException *             if pattern contains any syntax errors. */public static ColorPhrase from(Resources r, int patternResourceId) {return from(r.getText(patternResourceId));}/** * Entry point into this API; pattern must be non-null. *  * @throws IllegalArgumentException *             if pattern contains any syntax errors. */public static ColorPhrase from(CharSequence pattern) {return new ColorPhrase(pattern);}private ColorPhrase(CharSequence pattern) {curChar = (pattern.length() > 0) ? pattern.charAt(0) : EOF;this.pattern = pattern;// Invalidate the cached formatted text.formatted = null;separator = "{}";// initialize the default separatorouterColor = 0xFF666666;//initialize the default valueinnerColor =0xFFE6454A;//initialize the default value}/** * set the separator of the target，called after from() method. *  * @param _separator * @return */public ColorPhrase withSeparator(String _separator) {if (TextUtils.isEmpty(_separator)) {throw new IllegalArgumentException("separator must not be empty!");}if (_separator.length() > 2) {throw new IllegalArgumentException("separator‘s length must not be more than 3 charactors!");}this.separator = _separator;return this;}/** * init the outerColor *  * @param _outerColor * @return */public ColorPhrase outerColor(int _outerColor) {this.outerColor = _outerColor;return this;}/** * init the innerColor *  * @param _innerColor * @return */public ColorPhrase innerColor(int _innerColor) {this.innerColor = _innerColor;return this;}/** * cut the pattern with the separators and linked them with double link * structure; */private void createDoubleLinkWithToken() {// A hand-coded lexer based on the idioms in// "Building Recognizers By Hand".// http://www.antlr2.org/book/byhand.pdf.Token prev = null;Token next;while ((next = token(prev)) != null) {// Creates a doubly-linked list of tokens starting with head.if (head == null)head = next;prev = next;}}/** * Returns the next token from the input pattern, or null when finished * parsing. */private Token token(Token prev) {if (curChar == EOF) {return null;}if (curChar == getLeftSeparator()) {char nextChar = lookahead();if (nextChar == getLeftSeparator()) {return leftSeparator(prev);} else {return inner(prev);}}return outer(prev);}private char getLeftSeparator() {return separator.charAt(0);}private char getRightSeparator() {if (separator.length() == 2) {return separator.charAt(1);}return separator.charAt(0);}/** * Returns the text after replacing all keys with values. *  * @throws IllegalArgumentException *             if any keys are not replaced. */public CharSequence format() {if (formatted == null) {if (!checkPattern()) {throw new IllegalStateException("the separators don't match in the pattern!");}createDoubleLinkWithToken();// Copy the original pattern to preserve all spans, such as bold,// italic, etc.SpannableStringBuilder sb = new SpannableStringBuilder(pattern);for (Token t = head; t != null; t = t.next) {t.expand(sb);}formatted = sb;}return formatted;}/** * check if the pattern has legal separators *  * @return */private boolean checkPattern() {if (pattern == null) {return false;}char leftSeparator = getLeftSeparator();char rightSeparator = getRightSeparator();Stack<Character> separatorStack = new Stack<Character>();for (int i = 0; i < pattern.length(); i++) {char cur = pattern.charAt(i);if (cur == leftSeparator) {separatorStack.push(cur);} else if (cur == rightSeparator) {if (!separatorStack.isEmpty() && (separatorStack.pop() == leftSeparator)) {continue;} else {return false;}}}return separatorStack.isEmpty();}private InnerToken inner(Token prev) {// Store keys as normal Strings; we don't want keys to contain spans.StringBuilder sb = new StringBuilder();// Consume the left separator.consume();char rightSeparator = getRightSeparator();while (curChar != rightSeparator && curChar != EOF) {sb.append(curChar);consume();}if (curChar == EOF) {throw new IllegalArgumentException("Missing closing separator");}        //consume the right separator.consume();if (sb.length() == 0) {throw new IllegalStateException("Disallow empty content between separators,for example {}");}String key = sb.toString();return new InnerToken(prev, key, innerColor);}/** Consumes and returns a token for a sequence of text. */private OuterToken outer(Token prev) {int startIndex = curCharIndex;while (curChar != getLeftSeparator() && curChar != EOF) {consume();}return new OuterToken(prev, curCharIndex - startIndex, outerColor);}/** * Consumes and returns a token representing two consecutive curly brackets. */private LeftSeparatorToken leftSeparator(Token prev) {consume();consume();return new LeftSeparatorToken(prev, getLeftSeparator());}/** Returns the next character in the input pattern without advancing. */private char lookahead() {return curCharIndex < pattern.length() - 1 ? pattern.charAt(curCharIndex + 1) : EOF;}/** * Advances the current character position without any error checking. * Consuming beyond the end of the string can only happen if this parser * contains a bug. */private void consume() {curCharIndex++;curChar = (curCharIndex == pattern.length()) ? EOF : pattern.charAt(curCharIndex);}/** * Returns the raw pattern without expanding keys; only useful for * debugging. Does not pass through to {@link #format()} because doing so * would drop all spans. */@Overridepublic String toString() {return pattern.toString();}private abstract static class Token {private final Token prev;private Token next;protected Token(Token prev) {this.prev = prev;if (prev != null)prev.next = this;}/** Replace text in {@code target} with this token's associated value. */abstract void expand(SpannableStringBuilder target);/** Returns the number of characters after expansion. */abstract int getFormattedLength();/** Returns the character index after expansion. */final int getFormattedStart() {if (prev == null) {// The first token.return 0;} else {// Recursively ask the predecessor node for the starting index.return prev.getFormattedStart() + prev.getFormattedLength();}}}/** Ordinary text between tokens. */private static class OuterToken extends Token {private final int textLength;private int color;OuterToken(Token prev, int textLength, int _color) {super(prev);this.textLength = textLength;this.color = _color;}@Overridevoid expand(SpannableStringBuilder target) {int startPoint = getFormattedStart();int endPoint = startPoint + textLength;target.setSpan(new ForegroundColorSpan(color), startPoint, endPoint, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);}@Overrideint getFormattedLength() {return textLength;}}/** A sequence of two curly brackets. */private static class LeftSeparatorToken extends Token {private char leftSeparetor;LeftSeparatorToken(Token prev, char _leftSeparator) {super(prev);leftSeparetor = _leftSeparator;}@Overridevoid expand(SpannableStringBuilder target) {int start = getFormattedStart();target.replace(start, start + 2, String.valueOf(leftSeparetor));}@Overrideint getFormattedLength() {// for example,,Replace "{{" with "{".return 1;}}private static class InnerToken extends Token {/** The InnerText without separators,like '{' and '}'. */private final String innerText;private int color;InnerToken(Token prev, String _inner, int _color) {super(prev);this.innerText = _inner;color = _color;}@Overridevoid expand(SpannableStringBuilder target) {int replaceFrom = getFormattedStart();// Add 2 to account for the separators.int replaceTo = replaceFrom + innerText.length() + 2;target.replace(replaceFrom, replaceTo, innerText);target.setSpan(new ForegroundColorSpan(color), replaceFrom, replaceTo - 2, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);}@Overrideint getFormattedLength() {// Note that value is only present after expand. Don't error check// because this is all// private code.return innerText.length();}}}

好了，需要demo的朋友請點此下載

[Android]為TextView提供雙色文本配置的小工具ColorPhrase