在棒棒糖上断开的 TextView fromHtml 链接

Question

我们的应用程序有几个 TextViews 实例，其内容设置myTv.setText(Html.fromHtml());为适用于 Android 4.4.0 及更低版本。

从 4.4.2 和 Lollypop 开始，这些链接已停止工作。文本仍然带有下划线和超链接颜色，但点击它们不会产生任何结果。

不得不说，这些字段被标记为可复制粘贴的，众所周知，它与这些可生成对象有交互。

有没有人能够解决这个问题？

Answer 1

问题是，当在 TextView 中启用复制和粘贴时，Android 将使用 ArrowKeyMovementMethod，它支持选择文本但不支持单击链接。当您使用 LinkMovementMethod 时，您可以单击链接，但不能选择文本（无论您使用的是 Lollipop、KitKat 还是较低的 Android 版本）。

为了解决这个问题，我扩展了 ArrayKeyMovementMethod 类，并使用 LinkMovementMethod onTouchEvent 覆盖了 onTouchEvent。为了允许文本选择，我必须删除三行代码。由于我在具有大量文本格式的富文本编辑器中使用该类，因此我还添加了逻辑来查找单击的字符，无论文本大小、缩进或文本对齐方式如何。如果您想要一个可以很好地处理纯文本的简单解决方案，请在自定义 ArrowKeyMovementMethod 类中使用它：

@Override
public boolean onTouchEvent(TextView widget, Spannable buffer, MotionEvent event) {

    int action = event.getAction();
    if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_DOWN) {
        int x = (int) event.getX();
        int y = (int) event.getY();

        x -= widget.getTotalPaddingLeft();
        y -= widget.getTotalPaddingTop();

        x += widget.getScrollX();
        y += widget.getScrollY();

        Layout layout = widget.getLayout();
        int line = layout.getLineForVertical(y);
        int off = layout.getOffsetForHorizontal(line, x);

        ClickableSpan[] link = buffer.getSpans(off, off, ClickableSpan.class);

        if (link.length != 0) {
            if (action == MotionEvent.ACTION_UP) {
                link[0].onClick(widget);
            } else if (action == MotionEvent.ACTION_DOWN) {
                Selection.setSelection(buffer,
                        buffer.getSpanStart(link[0]),
                        buffer.getSpanEnd(link[0]));
            }

            return true;
        }
        /* These are the lines of code you want to remove
        else {
            Selection.removeSelection(buffer);
        }*/
    }

    return super.onTouchEvent(widget, buffer, event);
}

不要忘记调用：myTv.setMovementMethod(new ClickAndSelectMovementMethod());

如果您想要支持各种文本格式的版本，请改用：

import android.graphics.Rect;
import android.text.Layout;
import android.text.Selection;
import android.text.Spannable;
import android.text.Spanned;
import android.text.TextPaint;
import android.text.method.ArrowKeyMovementMethod;
import android.text.method.MovementMethod;
import android.text.style.AbsoluteSizeSpan;
import android.text.style.ClickableSpan;
import android.text.style.LeadingMarginSpan;
import android.view.MotionEvent;
import android.widget.TextView;

/**
 * ArrowKeyMovementMethod does support selection of text but not the clicking of
 * links. LinkMovementMethod does support clicking of links but not the
 * selection of text. This class adds the link clicking to the
 * ArrowKeyMovementMethod. We basically take the LinkMovementMethod onTouchEvent
 * code and remove the line Selection.removeSelection(buffer); which de-selects
 * all text when no link was found.
 */
public class ClickAndSelectMovementMethod extends ArrowKeyMovementMethod {

    private static Rect sLineBounds = new Rect();

    @Override
    public boolean onTouchEvent(TextView widget, Spannable buffer, MotionEvent event) {
        int action = event.getAction();

        if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_DOWN) {

            int index = getCharIndexAt(widget, event);
            if (index != -1) {
                ClickableSpan[] link = buffer.getSpans(index, index, ClickableSpan.class);
                if (link.length != 0) {
                    if (action == MotionEvent.ACTION_UP) {
                        link[0].onClick(widget);
                    } else if (action == MotionEvent.ACTION_DOWN) {
                        Selection.setSelection(buffer, buffer.getSpanStart(link[0]), buffer.getSpanEnd(link[0]));
                    }
                    return true;
                }
            }
            /*
             * else { Selection.removeSelection(buffer); }
             */

        }

        return super.onTouchEvent(widget, buffer, event);
    }

    private int getCharIndexAt(TextView textView, MotionEvent event) {
        // get coordinates
        int x = (int) event.getX();
        int y = (int) event.getY();
        x -= textView.getTotalPaddingLeft();
        y -= textView.getTotalPaddingTop();
        x += textView.getScrollX();
        y += textView.getScrollY();

        /*
         * Fail-fast check of the line bound. If we're not within the line bound
         * no character was touched
         */
        Layout layout = textView.getLayout();
        int line = layout.getLineForVertical(y);
        synchronized (sLineBounds) {
            layout.getLineBounds(line, sLineBounds);
            if (!sLineBounds.contains(x, y)) {
                return -1;
            }
        }

        // retrieve line text
        Spanned text = (Spanned) textView.getText();
        int lineStart = layout.getLineStart(line);
        int lineEnd = layout.getLineEnd(line);
        int lineLength = lineEnd - lineStart;
        if (lineLength == 0) {
            return -1;
        }
        Spanned lineText = (Spanned) text.subSequence(lineStart, lineEnd);

        // compute leading margin and subtract it from the x coordinate
        int margin = 0;
        LeadingMarginSpan[] marginSpans = lineText.getSpans(0, lineLength, LeadingMarginSpan.class);
        if (marginSpans != null) {
            for (LeadingMarginSpan span : marginSpans) {
                margin += span.getLeadingMargin(true);
            }
        }
        x -= margin;

        // retrieve text widths
        float[] widths = new float[lineLength];
        TextPaint paint = textView.getPaint();
        paint.getTextWidths(lineText, 0, lineLength, widths);

        // scale text widths by relative font size (absolute size / default size)
        final float defaultSize = textView.getTextSize();
        float scaleFactor = 1f;
        AbsoluteSizeSpan[] absSpans = lineText.getSpans(0, lineLength, AbsoluteSizeSpan.class);
        if (absSpans != null) {
            for (AbsoluteSizeSpan span : absSpans) {
                int spanStart = lineText.getSpanStart(span);
                int spanEnd = lineText.getSpanEnd(span);
                scaleFactor = span.getSize() / defaultSize;
                int start = Math.max(lineStart, spanStart);
                int end = Math.min(lineEnd, spanEnd);
                for (int i = start; i < end; i++) {
                    widths[i] *= scaleFactor;
                }
            }
        }

        // find index of touched character
        float startChar = 0;
        float endChar = 0;
        for (int i = 0; i < lineLength; i++) {
            startChar = endChar;
            endChar += widths[i];
            if (endChar >= x) {
                // which "end" is closer to x, the start or the end of the character?
                int index = lineStart + (x - startChar < endChar - x ? i : i + 1);
                return index;
            }
        }

        return -1;
    }
}