克隆SpannableStringBuilder

Question

我正在使用一个Activity来解析带有标记字符的文本.我正在做的是将它们转换为几种类型的ClickableSpans.

问题是我需要实现一个函数(让我们称之为函数B),这意味着有重叠的ClickableSpans并导致一些问题.

所以我现在正在做的是在检测重叠跨度的同时创建一个新的SSB,并删除我不需要这个特定功能的SSB.工作正常.

但是,我需要能够回到之前的SSB,这似乎不起作用.

一步步:

// I CREATE THE SSBs
...
static SpannableStringBuilder ssb;
static SpannableStringBuilder ssbCopy;

// I IMPLEMENT MY CUSTOM FUNCTION THAT PARSES THE TEXT AND SETS THE SBB AS A TEXTVIEW CONTENT
...
textView.setMovementMethod(new LinkTouchMovementMethod());
ssb = addClickablePart(chapterTextStr, markupCharactersArray);
textView.setText(ssb);

// WHEN A BUTTON IS CLICKED I IMPLEMENT MY FUNCTION B. WHERE I CREATE A COPY OF MY ORIGINAL SSB AND STORE IT IN ssbCopy, AND SET IT AS THE TEXTVIEW CONTENT
...
ssbCopy = SpannableStringBuilder.valueOf(ssb);

// I REMOVE THE OVERLAPPING SPANS
...
overlapSpans = ssbCopy.getSpans(index, index+word.length(), TouchableSpan.class);

for (int c=0;c<overlapSpans.length;c++) {                       
    ssbCopy.removeSpan(overlapSpans[c]);
}                       

// I SET THE NEW CLICKABLE SPANS
...
ssbCopy.setSpan(touchableSpan, index, index + word.length(), 0);

// AND SET THE NEW SSB CONTENT TO THE TEXTVIEW
textView.setText(ssbCopy);

// EVERYTHING WORKS FINE UP TO HERE
// BUT WHEN I TRY TO SET BACK THE ORIGINAL SSB BACK AS THE CONTENT OF MY TEXTVIEW WHEN THE USER CLICKS A BUTTON
...
textView.setText(ssb);

// THE ORIGINAL SSB IS EXACTLY LIKE THE COPY (ssbCopy) AND CONTAINS THE SAME CLICKABLE SPANS I ADDED. NOT ONLY THE ORIGINAL ONES

我想这听起来有点令人困惑,我不确定我是否正确解释,但我不能解决这个问题.

编辑:

根据kcoppock的回答,我知道克隆ssb是不可能的,而valueOf(ssb)只是对象的副本.所以我最终通过循环遍历所有元素并将它们应用到新的ssb来手动克隆我的"ssb".像这样:

TouchableSpan[] spans = ssb.getSpans(0, ssb.length(), TouchableSpan.class);

ssbCopy = new SpannableStringBuilder(chapterTextStr+"dsadsa");

for (int c=0;c<spans.length;c++) {
    TouchableSpan obj = spans[c];

    ssbCopy.setSpan(obj, ssb.getSpanStart(obj), ssb.getSpanEnd(obj), 0);
}

顺便说一句,TouchableSpan是我创建的自定义类,它扩展了ClickableSpan

Answer 1

这里的问题是你对valueOf(). 它不会做你认为它会做的事。它所做的只是返回传入的对象（如果它是SpannableStringBuilder; ）否则，它将给定包装CharSequence在SpannableStringBuilder. 从源头看：

public static SpannableStringBuilder valueOf(CharSequence source) {
    if (source instanceof SpannableStringBuilder) {
        return (SpannableStringBuilder) source;
    } else {
        return new SpannableStringBuilder(source);
    }
}

所以本质上是：

ssb == SpannableStringBuilder.valueOf(ssb);

它们是同一个对象。SpannableStringBuilder没有实现Cloneable，因此除了生成两个副本之外，没有简单的方法来制作副本，例如：

ssb = addClickablePart(chapterTextStr, markupCharactersArray);
ssbCopy = addClickablePart(chapterTextStr, markupCharactersArray);