Android文本超链接实现及滑动冲突处理

我们知道使用SpannableString和ClickableSpan可以实现部分文字高亮点击效果，但是设置了setMovementMethod(LinkMovementMethod.getInstance())会使文字自带滑动。最近有个需求是在Dialog中显示高亮可点击跳转的文字，但是受Dialog大小限制，需要添加ScrollView以上下滑动，这样就会出现滑动冲突，参考一些资料后琢磨出了解决方案。

ps：setMovementMethod(LinkMovementMethod.getInstance())不是自带滑动效果吗？为啥还用ScrollView包一层？实际上这个自带点击的滑动效果贼垃圾，一碰就触发点击了，根本不滑，谁用谁知道

看下效果

冲突.png

贴出主要代码

1、高亮文字和点击跳转——自定义Span

public class CustomSpan extends URLSpan {

    public Context mContext;
    public String mId;

    public CustomSpan(String url) {
        super(url);
    }

    public CustomSpan(String url, Context context, String id) {
        super(url);
        this.mContext = context;
        this.mId = id;
    }

    @Override
    public void updateDrawState(@NonNull TextPaint ds) {
        super.updateDrawState(ds);
        ds.setColor(Color.parseColor("#5F7AB8"));
        ds.setUnderlineText(false);
    }

    @Override
    public void onClick(View widget) {
        if (!TextUtils.isEmpty(mId)) {
            Intent intent = new Intent(mContext, XXX.class);
            intent.putExtra("id", mId);
            mContext.startActivity(intent);
        }
    }

    /**
     *
     * @param context
     * @param spannableContent 要匹配的高亮可点击内容
     * @param content 全文
     * @param id
     * @return
     */
    public static SpannableString getSpannableContent(Context context, SpannableString spannableContent, String content, String id) {
        Pattern pattern = Pattern.compile(content, Pattern.CASE_INSENSITIVE);
        Matcher matcher = pattern.matcher(spannableContent);
        while (matcher.find()) {
            URLSpan span = new CustomSpan(content, context, id);
            spannableContent.setSpan(span, matcher.start(0), matcher.end(0), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        }
        return spannableContent;
    }

}

获取Dialog中要显示的内容，Conflict对象中有id和name，具体我就不写了

private SpannableString getConflictMessage(List<Conflict> conflicts) {
    String str = "与{count}个计划{name}时间冲突，确认接受？";
    str = str.replace("{count}", conflicts.size() + "");
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < conflicts.size(); i++) {
        sb.append("【").append(conflicts.get(i).getName()).append("】");
        if (i != conflicts.size() - 1) {
            sb.append("、");
        }
    }
    str = str.replace("{name}", sb);

    SpannableString ss = new SpannableString(str);
    for (int i = 0; i < conflicts.size(); i++) {
        StringBuilder match = new StringBuilder();
        match.append("【").append(conflicts.get(i).getName()).append("】");
        if (i != conflicts.size() - 1) {
            match.append("、");
        }
        ss = CustomSpan.getSpannableContent(mContext, ss, match.toString(), String.valueOf(conflicts.get(i).getId()));
    }
    return ss;
}

再给TextView加上tv.setMovementMethod(LinkMovementMethod.getInstance());就实现了部分文字高亮点击跳转

2、滑动冲突处理——自定义MovementMethod

这里就是复制修改下LinkMovementMethod的源码，把滑动部分去掉就可以了，LinkMovementMethod的源码就不贴了，用到时自己对照查看，这里只贴CustomMovementMethod代码

public class CustomMovementMethod extends BaseMovementMethod {

    private static CustomMovementMethod customMovementMethod;

    public static CustomMovementMethod getInstance() {
        if (customMovementMethod == null) {
            synchronized (CustomMovementMethod .class) {
                if (customMovementMethod == null) {
                    customMovementMethod = new CustomMovementMethod ();
                }
            }
        }
        return customMovementMethod;
    }

    @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) {
                    // 只处理点击事件
                    link[0].onClick(widget);
                }
                return true;
            }
        }
        return super.onTouchEvent(widget, buffer, event);
    }

    private CustomMovementMethod () {

    }
}

这样在ScrollView中的TextView就可以滑动了

3、Dialog大小适配——自定义可设置最大高度的ScrollView

如果Dialog中ScrollView高度写死，文字多了可视范围大，效果好，当只有一行时就尴尬了，于是就设置个最大高度吧

public class MaxHeightScrollView extends ScrollView {

    private int maxHeight;

    public MaxHeightScrollView(Context context) {
        super(context);
    }

    public MaxHeightScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.MaxHeightScrollView);
        maxHeight = typedArray.getDimensionPixelSize(R.styleable.MaxHeightScrollView_max_height, 0);
    }

    public MaxHeightScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public void setMaxHeight(int maxHeight) {
        this.maxHeight = maxHeight;
        requestLayout();
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        if (maxHeight > 0) {
            heightMeasureSpec = MeasureSpec.makeMeasureSpec(maxHeight, MeasureSpec.AT_MOST);
        }
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
}


attrs.xml中
<declare-styleable name="MaxHeightScrollView">
    <attr name="max_height" format="dimension"/>
</declare-styleable>

以上几步在Dialog中使用

TextView tv = (TextView) dialog.findViewById(R.id.message);
tv.setText(getConflictMessage(conflicts));
tv.setMovementMethod(CustomMovementMethod.getInstance());

tv.setMovementMethod(CustomMovementMethod.getInstance());是重点，漏了这句点击没有效果

如果有更好的实现方法告诉下，互相学习