TouchMovementMethod.java 文件源码

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

    int action = event.getAction();
    if(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);

        mClickLinks = buffer.getSpans(off, off, ClickableSpan.class);
        if(mClickLinks.length > 0){
            // 点击的是Span区域，不要把点击事件传递
            setPassToTv(false);
            Selection.setSelection(buffer,
                    buffer.getSpanStart(mClickLinks[0]),
                    buffer.getSpanEnd(mClickLinks[0]));
            //设置点击区域的背景色
            mBgSpan = new BackgroundColorSpan(mPressSpanBgColor);
            buffer.setSpan(mBgSpan,
                    buffer.getSpanStart(mClickLinks[0]),
                    buffer.getSpanEnd(mClickLinks[0]),
                    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        }else{
            setPassToTv(true);
            // textView选中效果
            widget.setBackgroundColor(mPressSpanBgColor);
        }

    }else if(action == MotionEvent.ACTION_UP){
        if(mClickLinks.length > 0){
            mClickLinks[0].onClick(widget);
            if(mBgSpan != null){//移除点击时设置的背景span
                buffer.removeSpan(mBgSpan);
            }
        }
        Selection.removeSelection(buffer);
        widget.setBackgroundColor(mTextViewBgColor);
    }else if(action == MotionEvent.ACTION_MOVE){
        //这种情况不用做处理
    }else{
        if(mBgSpan != null){//移除点击时设置的背景span
            buffer.removeSpan(mBgSpan);
        }
        widget.setBackgroundColor(mTextViewBgColor);
    }
    return Touch.onTouchEvent(widget, buffer, event);
}