Cocos2dx change line

在 cocos2dx change line 的实现中，我们能够简单的使用 dimensions属性控制换行。使用它仅仅需将相应的參数值传入构造函数，或者调用 setDimensions 函数就可以。

它的换行策略是：当一个单词超出限制长度时。将它移动到下一行。

有时这样的策略并不合适。

比如。在某些语言中，单词都比較长。

假设採用这样的策略。会出现每一行中仅仅有一个单词。

因此须要更改换行策略。当超出限制长度时，使用 - 作为一个分隔单词的标志。

换行策略调用

通过查看Cocos2d-x中换行的实现方式，我发现换行策略是区分平台编程出来的代码。

也就是说。为了更改换行策略，我须要分别编写 IOS 和 Java 两部分代码。

由于我的目标平台是 Android 平台，因此我仅仅对Java文件进行了更改。IOS 平台的换行策略调用的是系统函数，有兴趣研究的读者能够跟踪源代码更改。入口函数为:

bool CCTexture2D::initWithString(const char *text, ccFontDefinition *textDefinition)
{
    ......
 
    CCImage* pImage = new CCImage();
    do
    {
        CC_BREAK_IF(NULL == pImage);
        
        bRet = pImage->initWithStringShadowStroke(text,
                                                  (int)textDefinition->m_dimensions.width,
                                                  (int)textDefinition->m_dimensions.height,
                                                  eAlign,
                                                  textDefinition->m_fontName.c_str(),
                                                  textDefinition->m_fontSize,
                                                  textDefinition->m_fontFillColor.r / 255,
                                                  textDefinition->m_fontFillColor.g / 255,
                                                  textDefinition->m_fontFillColor.b / 255,
                                                  shadowEnabled,
                                                  shadowDX,
                                                  shadowDY,
                                                  shadowOpacity,
                                                  shadowBlur,
                                                  strokeEnabled,
                                                  strokeColorR,
                                                  strokeColorG,
                                                  strokeColorB,
                                                  strokeSize);
        
        
        CC_BREAK_IF(!bRet);
        bRet = initWithImage(pImage);
        
    } while (0);
    
    ......
}

Android 平台相应的 Java 文件位于 $(2DX-Root)/cocos2dx/platform/android/java/src/org/cocos2dx/lib 目录中。文件名称是 Cocos2dxBitmap.java

首先，我添加了 divideStringWithMaxWidthByFlag 函数。将它作为还有一个换行策略的实现函数。

// add by fansy for "—" style words
    private static LinkedList<String> divideStringWithMaxWidthByFlag(
           final String pString, final int pMaxWidth, final Paint pPaint) {
        final int charLength = pString.length();
        int start = 0;
        int tempWidth = 0;
        LinkedList<String> strList = new LinkedList<String>();
        
        if( !isChinese(pString) )
        {
            /* Break a String into String[] by the width & should wrap the word. */
            for (int i = 1; i < charLength-1; ++i) {
                tempWidth = (int) FloatMath.ceil(pPaint.measureText(pString, start,i+1));
                if (tempWidth >= pMaxWidth) {
                    if(pString.charAt(i) == ‘ ‘) //end with " "
                    {
                        //change line at i
                        strList.add(pString.substring(start, i));
                        i = i + 1; // skip space
                    }
                    else if(i>1 && pString.charAt(i-2) == ‘ ‘) //only one "-" left after change line
                    {
                        //change line at i-2
                        strList.add(pString.substring(start, i-2));
                        i = i -2; // skip space
                    }
                    else if(i>0 && pString.charAt(i-1) == ‘ ‘) //only one "-" left after change line
                    {
                        //change line at i-1
                        strList.add(pString.substring(start, i-1));
                        i = i -1; // skip space
                    }
                    else if(i>0) //replace "-" at i-2
                    {
                        //split at i-1 add "-" at tail change line at i-1
                        strList.add(pString.substring(start, i-1)+"-");
                        i--;
                    }
                    
                    /* Remove spaces at the beginning of a new line. */
                    while (pString.charAt(i) == ‘ ‘) {
                        ++i;
                    }
                    
                    start = i;
                }
            }
            
            /* Add the last chars. */
            if (start < charLength) {
                strList.add(pString.substring(start));
            }
        }
        else
        {
            strList = divideStringWithMaxWidth(pString, pMaxWidth, pPaint);
        }
        return strList;
    }
    
    // 依据Unicode编码完美的推断中文汉字和符号
    private static boolean isChinese(char c) {
        Character.UnicodeBlock ub = Character.UnicodeBlock.of(c);
        if (ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS
            || ub == Character.UnicodeBlock.CJK_COMPATIBILITY_IDEOGRAPHS
            || ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A
            || ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_B
            || ub == Character.UnicodeBlock.CJK_SYMBOLS_AND_PUNCTUATION
            || ub == Character.UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS
            || ub == Character.UnicodeBlock.GENERAL_PUNCTUATION) {
            return true;
        }
        return false;
    }
    
    // 完整的推断中文汉字和符号
    public static boolean isChinese(String strName) {
        char[] ch = strName.toCharArray();
        for (int i = 0; i < ch.length; i++) {
            char c = ch[i];
            if (isChinese(c)) {
                return true;
            }
        }
        return false;
    }
    
 //end add by fansy

添加函数之后。改动在 splitString 中的调用：

private static String[] splitString(final String pString,
            final int pMaxWidth, final int pMaxHeight, final Paint pPaint) {
        final String[] lines = pString.split("\\n");
        String[] ret = null;
        final FontMetricsInt fm = pPaint.getFontMetricsInt();
        final int heightPerLine = (int) Math.ceil(fm.bottom - fm.top);
        final int maxLines = pMaxHeight / heightPerLine;
 
        if (pMaxWidth != 0) {
            final LinkedList<String> strList = new LinkedList<String>();
            for (final String line : lines) {
                /*
                 * The width of line is exceed maxWidth, should divide it into
                 * two or more lines.
                 */
                final int lineWidth = (int) FloatMath.ceil(pPaint
                        .measureText(line));
                if (lineWidth > pMaxWidth) {
                    strList.addAll(Cocos2dxBitmap.divideStringWithMaxWidthByFlag(
                            line, pMaxWidth, pPaint));
                } else {
                    strList.add(line);
        ......
}