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Edit Spanned Text

由 守給你的承諾、 提交于 2019-12-21 23:21:27

问题


I need to design an editor for my project that allow user to style some part of the text. I have used an EditText and bold selected text by adding following codes in onClickListener of a button.

String selectedText = "<b>" + mEditTextContent.getText().toString().substring(
                    mEditTextContent.getSelectionStart(),
                    mEditTextContent.getSelectionEnd()
            ) + "</b>";

mEditTextContent.getText().replace(
                    mEditTextContent.getSelectionStart(),
                    mEditTextContent.getSelectionEnd(),
                    Html.fromHtml(selectedText)
            );

But i am wonder how i can toggle bold style? For example if selected text is already bolded, unbold it, and if not, bold it.


回答1:


I write these codes to toggle bold & italic styles of selected text.

Create a class and name it SpanStyleHelper:

public class SpanStyleHelper
{
protected EditText mEditText;
protected Spannable mSpannable;
protected int mSelectedTextStart;
protected int mSelectedTextEnd;

public SpanStyleHelper(EditText editText)
{
    mEditText = editText;
    mSpannable = mEditText.getText();
    mSelectedTextStart = mEditText.getSelectionStart();
    mSelectedTextEnd = mEditText.getSelectionEnd();
}

public Spannable boldSelectedText()
{
    Log.d("Ramansoft", "Try to bold selected text..");

    StyleSpan[] styleSpans = mEditText.getText().getSpans(
            mSelectedTextStart,
            mSelectedTextEnd,
            StyleSpan.class
    );

    if(styleSpans.length > 0) {

        int lastSpanEnd = 0;

        for (StyleSpan styleSpan : styleSpans) {
            /**
             * Save old style
             */
            int oldStyle = styleSpan.getStyle();


            /**
             * Get start and end of span
             */
            int spanStart = mSpannable.getSpanStart(styleSpan);
            int spanEnd = mSpannable.getSpanEnd(styleSpan);


            /**
             * Before bold this span, we check if any unspanned
             * text between this span and last span remains. if any
             * unspanned text exist, we should bold it
             */
            if(spanStart > lastSpanEnd)
            {
                mSpannable.setSpan(
                        new StyleSpan(Typeface.BOLD),
                        lastSpanEnd,
                        spanStart,
                        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
                );
            }

            /**
             * Update last span end
             */
            lastSpanEnd = spanEnd;


            /**
             * Remove the span
             */
            mSpannable.removeSpan(styleSpan);


            /**
             * Because we just need change selected text,
             * if span start is lower than selected text start or
             * if span end is higher than selected text end start
             * we should restore span for unselected part of span
             */
            if (spanStart < mEditText.getSelectionStart()) {
                mSpannable.setSpan(
                        new StyleSpan(oldStyle),
                        spanStart,
                        mSelectedTextStart,
                        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
                );
            }

            if (spanEnd > mEditText.getSelectionEnd()) {
                mSpannable.setSpan(
                        new StyleSpan(oldStyle),
                        mSelectedTextEnd,
                        spanEnd,
                        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
                );
            }

            /**
             * We want to add bold style to current style
             * so we most detect current style and change
             * the style depend on current style
             */
            if (oldStyle == Typeface.ITALIC) {
                mSpannable.setSpan(
                        new StyleSpan(Typeface.BOLD_ITALIC),
                        spanStart,
                        spanEnd,
                        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
                );
            } else {
                mSpannable.setSpan(
                        new StyleSpan(Typeface.BOLD),
                        spanStart,
                        spanEnd,
                        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
                );
            }
        }

        /**
         * Now we should check if any
         * unspanned selected text remains
         */
        if(mSelectedTextEnd != lastSpanEnd)
        {
            mSpannable.setSpan(
                    new StyleSpan(Typeface.BOLD),
                    lastSpanEnd,
                    mSelectedTextEnd,
                    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
            );
        }
    }
    else
    {
        mSpannable.setSpan(
                new StyleSpan(Typeface.BOLD),
                mSelectedTextStart,
                mSelectedTextEnd,
                Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
        );
    }

    return mSpannable;
}

public Spannable unBoldSelectedText()
{
    Log.d("Ramansoft", "Try to unbold selected text..");

    StyleSpan[] styleSpans = mEditText.getText().getSpans(
            mSelectedTextStart,
            mSelectedTextEnd,
            StyleSpan.class
    );

    for(StyleSpan styleSpan:styleSpans)
    {
        /**
         * Save old style
         */
        int oldStyle = styleSpan.getStyle();


        /**
         * Get start and end of span
         */
        int spanStart = mSpannable.getSpanStart(styleSpan);
        int spanEnd = mSpannable.getSpanEnd(styleSpan);


        /**
         * Remove the span
         */
        mSpannable.removeSpan(styleSpan);


        /**
         * Because we just need change selected text,
         * if span start is lower than selected text start or
         * if span end is higher than selected text end start
         * we should restore span for unselected part of span
         */
        if(spanStart < mEditText.getSelectionStart())
        {
            mSpannable.setSpan(
                    new StyleSpan(oldStyle),
                    spanStart,
                    mSelectedTextStart,
                    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
            );
        }

        if(spanEnd > mEditText.getSelectionEnd())
        {
            mSpannable.setSpan(
                    new StyleSpan(oldStyle),
                    mSelectedTextEnd,
                    spanEnd,
                    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
            );
        }

        /**
         * Because we just want to remove bold style,
         * if the span has another style, we should restore it
         */
        if(oldStyle == Typeface.BOLD_ITALIC)
        {
            mSpannable.setSpan(
                    new StyleSpan(Typeface.ITALIC),
                    spanStart,
                    spanEnd,
                    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
            );
        }
    }

    return mSpannable;
}

public Spannable toggleBoldSelectedText()
{
    Log.d("Ramansoft", "Try to toggle bold selected text..");

    boolean isAllSpansBold = true;


    StyleSpan[] styleSpans = mEditText.getText().getSpans(
            mSelectedTextStart,
            mSelectedTextEnd,
            StyleSpan.class
    );


    if(styleSpans.length == 0)
    {
        return boldSelectedText();
    }
    else
    {
        for(StyleSpan styleSpan:styleSpans)
        {
            Log.d("Ramansoft", "styleSpan.getStyle() = " + styleSpan.getStyle());

            if (styleSpan.getStyle() != Typeface.BOLD && styleSpan.getStyle() != Typeface.BOLD_ITALIC) {
                isAllSpansBold = false;
                break;
            }
        }

        Log.d("Ramansoft", "isAllSpansBold = " + isAllSpansBold);


        if(isAllSpansBold)
            return unBoldSelectedText();
        else
            return boldSelectedText();
    }

}

public Spannable italicSelectedText()
{
    Log.d("Ramansoft", "Try to italic selected text..");

    StyleSpan[] styleSpans = mEditText.getText().getSpans(
            mSelectedTextStart,
            mSelectedTextEnd,
            StyleSpan.class
    );

    if(styleSpans.length > 0)
    {
        int lastSpanEnd = 0;

        for (StyleSpan styleSpan : styleSpans) {
            /**
             * Save old style
             */
            int oldStyle = styleSpan.getStyle();


            /**
             * Get start and end of span
             */
            int spanStart = mSpannable.getSpanStart(styleSpan);
            int spanEnd = mSpannable.getSpanEnd(styleSpan);


            /**
             * Before italic this span, we check if any unspanned
             * text between this span and last span remains. if any
             * unspanned text exist, we should italic it
             */
            if(spanStart > lastSpanEnd)
            {
                mSpannable.setSpan(
                        new StyleSpan(Typeface.ITALIC),
                        lastSpanEnd,
                        spanStart,
                        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
                );
            }


            /**
             * Update last span end
             */
            lastSpanEnd = spanEnd;


            /**
             * Remove the span
             */
            mSpannable.removeSpan(styleSpan);


            /**
             * Because we just need change selected text,
             * if span start is lower than selected text start or
             * if span end is higher than selected text end start
             * we should restore span for unselected part of span
             */
            if (spanStart < mEditText.getSelectionStart()) {
                mSpannable.setSpan(
                        new StyleSpan(oldStyle),
                        spanStart,
                        mSelectedTextStart,
                        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
                );
            }

            if (spanEnd > mEditText.getSelectionEnd()) {
                mSpannable.setSpan(
                        new StyleSpan(oldStyle),
                        mSelectedTextEnd,
                        spanEnd,
                        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
                );
            }

            /**
             * We want to add bold style to current style
             * so we most detect current style and change
             * the style depend on current style
             */
            if (oldStyle == Typeface.BOLD) {
                mSpannable.setSpan(
                        new StyleSpan(Typeface.BOLD_ITALIC),
                        spanStart,
                        spanEnd,
                        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
                );
            } else {
                mSpannable.setSpan(
                        new StyleSpan(Typeface.ITALIC),
                        spanStart,
                        spanEnd,
                        Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
                );
            }
        }

        /**
         * Now we should check if any
         * unspanned selected text remains
         */
        if(mSelectedTextEnd != lastSpanEnd)
        {
            mSpannable.setSpan(
                    new StyleSpan(Typeface.ITALIC),
                    lastSpanEnd,
                    mSelectedTextEnd,
                    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
            );
        }
    }
    else
    {
        mSpannable.setSpan(
                new StyleSpan(Typeface.ITALIC),
                mSelectedTextStart,
                mSelectedTextEnd,
                Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
        );
    }

    return mSpannable;
}

public Spannable unItalicSelectedText()
{
    Log.d("Ramansoft", "Try to un-italic selected text..");

    StyleSpan[] styleSpans = mEditText.getText().getSpans(
            mSelectedTextStart,
            mSelectedTextEnd,
            StyleSpan.class
    );

    for(StyleSpan styleSpan:styleSpans)
    {
        /**
         * Save old style
         */
        int oldStyle = styleSpan.getStyle();


        /**
         * Get start and end of span
         */
        int spanStart = mSpannable.getSpanStart(styleSpan);
        int spanEnd = mSpannable.getSpanEnd(styleSpan);


        /**
         * Remove the span
         */
        mSpannable.removeSpan(styleSpan);


        /**
         * Because we just need change selected text,
         * if span start is lower than selected text start or
         * if span end is higher than selected text end start
         * we should restore span for unselected part of span
         */
        if(spanStart < mEditText.getSelectionStart())
        {
            mSpannable.setSpan(
                    new StyleSpan(oldStyle),
                    spanStart,
                    mSelectedTextStart,
                    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
            );
        }

        if(spanEnd > mEditText.getSelectionEnd())
        {
            mSpannable.setSpan(
                    new StyleSpan(oldStyle),
                    mSelectedTextEnd,
                    spanEnd,
                    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
            );
        }

        /**
         * Because we just want to remove bold style,
         * if the span has another style, we should restore it
         */
        if(oldStyle == Typeface.BOLD_ITALIC)
        {
            mSpannable.setSpan(
                    new StyleSpan(Typeface.BOLD),
                    spanStart,
                    spanEnd,
                    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE
            );
        }
    }

    return mSpannable;
}

public Spannable toggleItalicSelectedText()
{
    Log.d("Ramansoft", "Try to toggle italic selected text..");

    boolean isAllSpansItalic = true;


    StyleSpan[] styleSpans = mEditText.getText().getSpans(
            mSelectedTextStart,
            mSelectedTextEnd,
            StyleSpan.class
    );


    if(styleSpans.length == 0)
    {
        return italicSelectedText();
    }
    else
    {
        for(StyleSpan styleSpan:styleSpans)
        {
            Log.d("Ramansoft", "styleSpan.getStyle() = " + styleSpan.getStyle());

            if (styleSpan.getStyle() != Typeface.ITALIC && styleSpan.getStyle() != Typeface.BOLD_ITALIC) {
                isAllSpansItalic = false;
                break;
            }
        }

        Log.d("Ramansoft", "isAllSpansItalic = " + isAllSpansItalic);


        if(isAllSpansItalic)
            return unItalicSelectedText();
        else
            return italicSelectedText();
    }
}

Here is the code to use SpanStyleHelper in OnClickListener:

public class onButtonBoldClick implements ImageButton.OnClickListener {

    @Override
    public void onClick(View v)
    {
        SpanStyleHelper spanStyleHelper = new SpanStyleHelper(mEditTextContent);
        mEditTextContent.setText(
                spanStyleHelper.toggleBoldSelectedText()
        );
    }
}

public class onButtonItalicClick implements ImageButton.OnClickListener {

    @Override
    public void onClick(View v)
    {
        SpanStyleHelper spanStyleHelper = new SpanStyleHelper(mEditTextContent);
        mEditTextContent.setText(
                spanStyleHelper.toggleItalicSelectedText()
        );
    }
}


来源：https://stackoverflow.com/questions/36290847/edit-spanned-text

标签
android
spanned
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