ClickableSpan奇怪的行为：点击空白时调用onClick（） [英] ClickableSpan strange behavior:onClick() called when clicking empty space

问题描述

我有一个 TextView 和 ClickableSpan ，因为layout_height和layout_width都是wrap_content。

当 TextView 中的文本不太长时，它可以正常工作。
当文本足够长以至于需要2行时，它也可以正常工作，但有一些奇怪的行为。

那是当我点击第二行line的空白空间（未填充文本但是 TextView的一部分）， ClickableSpan onClick （）回调被调用。

我不指望这是因为我只点击了空白空间，而没有点击空白文本。
虽然它并没有太大影响，但我想知道背后是什么。

我设置了 ClickableSpan 以下代码：

  TextView tv =（TextView）findViewById（R.id.text）; 
 tv.setText（TEXT TEXT TEXT TEXT）; 
 SpannableStringBuilder ssb = new SpannableStringBuilder（）; 
 ssb.append（tv.getText（））; 
 ssb.setSpan（new TestClickableSpan（），ssb.length（） -  5，ssb.length（），0）; 
 tv.setText（ssb）; 
 tv.setMovementMethod（LinkMovementMethod.getInstance（））; 
 tv.setOnTouchListener（new TextViewOnTouchListener（））; b 
 
 
 $ b 
  class TextViewOnTouchListener实现OnTouchListener {
 $ b $ @覆盖
 public boolean onTouch（View v，MotionEvent event）{
 Log.d（TextView，onTouch ）; 
返回false; 
} 
} 
  

TestClickableSpan：



  class TestClickableSpan extends ClickableSpan {
 $ b @Override 
 public void onClick（View arg0）{
 Log.d （ClickableSpan，确认OnClick：+ arg0.toString（））; 
} 
} 
  




解决方案

I设法通过扩展LinkMovementMethod来解决它，并检查触摸事件
offset是否等于或大于文本长度：



  public class MovementMethod extends LinkMovementMethod {
 $ b $ @Override 
 public boolean onTouchEvent（TextView小部件，Spannable缓冲区，MotionEvent事件）{
 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（）; 
 
布局布局= widget.getLayout（）; 
 int line = layout.getLineForVertical（y）; 
 int off = layout.getOffsetForHorizo​​ntal（line，x）; 
 
 if（off> = widget.getText（）。length（））{
 //返回true，所以点击不会在剩余的空白区域被触发
 return真正; 
} 
} 
 
返回super.onTouchEvent（widget，buffer，event）; 
} 
} 
  




I have a TextView with ClickableSpan in that both layout_height and layout_width is wrap_content.

When the text in TextView in not too long, it work fine. When the text is long enough such that it take 2 line, it also work fine but have some strange behavior.

That is when I clicked on the second line's empty space(not fill with text yet but part of TextView) , the ClickableSpan onClick() callback is called.

I do not expect this as I clicked the empty space only but not the spanned text. Although it does not affect much, I want to know what is behind.

I set the ClickableSpan with below code:

TextView tv = (TextView) findViewById(R.id.text);
tv.setText("TEXT TEXT TEXT TEXT");
SpannableStringBuilder ssb = new SpannableStringBuilder();
ssb.append(tv.getText());
ssb.setSpan(new TestClickableSpan(), ssb.length()-5, ssb.length(), 0);
tv.setText(ssb);
tv.setMovementMethod(LinkMovementMethod.getInstance());
tv.setOnTouchListener(new TextViewOnTouchListener());

The TextViewOnTouchListener:

class TextViewOnTouchListener implements OnTouchListener{

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            Log.d("TextView", "onTouch");
            return false;
        }       
}

The TestClickableSpan:

class TestClickableSpan extends ClickableSpan{

        @Override
        public void onClick(View arg0) {
            Log.d("ClickableSpan", "Confirm OnClick: "+arg0.toString());
        }       
    }

解决方案

I managed to solve it by extending LinkMovementMethod, and check whether the touch event offset is equals or bigger than the text lenght:

public class MovementMethod extends LinkMovementMethod {

    @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);

            if (off >= widget.getText().length()) {
               // Return true so click won't be triggered in the leftover empty space
                return true;
            }
        }

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

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