ClickableSpan使用问题

• 当给文字设置clickablespan是，点击时会触发TextView的点击事件

从TextView的源码看起，找到TextView的onTouchEvent的方法

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        final int action = event.getActionMasked();
        if (mEditor != null) {
            mEditor.onTouchEvent(event);
            if (mEditor.mSelectionModifierCursorController != null &&
                    mEditor.mSelectionModifierCursorController.isDragAcceleratorActive()) {
                return true;
            }
        }
        final boolean superResult = super.onTouchEvent(event);
    
...
        
        final boolean touchIsFinished = (action == MotionEvent.ACTION_UP) &&
                (mEditor == null || !mEditor.mIgnoreActionUpEvent) && isFocused();
         if ((mMovement != null || onCheckIsTextEditor()) && isEnabled()
                && mText instanceof Spannable && mLayout != null) {
            boolean handled = false;
            if (mMovement != null) {
                handled |= mMovement.onTouchEvent(this, (Spannable) mText, event);
            }
            final boolean textIsSelectable = isTextSelectable();
            if (touchIsFinished && mLinksClickable && mAutoLinkMask != 0 && textIsSelectable) {
                
                ClickableSpan[] links = ((Spannable) mText).getSpans(getSelectionStart(),
                        getSelectionEnd(), ClickableSpan.class);
                if (links.length > 0) {
                    links[0].onClick(this);
                    handled = true;
                }
            }
            
        return superResult;
    }

可以看到调用了super.onTouchEvent();，所以会触发TextView的监听事件，接着执行clickablespan的点击事件。

ClickableSpan[] links = ((Spannable) mText).getSpans(getSelectionStart(), getSelectionEnd(), ClickableSpan.class);
 if (links.length > 0) { 
  links[0].onClick(this); 
  handled = true; }

• 当点击未设置span的textview部分时，发现textview消费了事件，并没有传递给viewgroup

设置clickablespan使设置了一个LinkMovementMethod，看一下LinkMovementMehod的源码

@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;
            } else {
                Selection.removeSelection(buffer);
            }
        }
        return super.onTouchEvent(widget, buffer, event);
    }

可以看到当点击设置了span的textview时return true，如果点击的是没有设置span的text或者空白部分时返回的是一个super.onTouchEvent(); ，这是一个true，也就是默认消费了事件。所以我们要重写LinkMovementMethod中的onTouchEvent，让最后默认返回显式为return false。即不消耗事件，事件继续向上传递。

但是这样修改完之后还是不能解决这个问题，问题出在textview的setMovementMethod方法里面：

public final void setMovementMethod(MovementMethod movement) {
        if (mMovement != movement) {
            mMovement = movement;
            if (movement != null && !(mText instanceof Spannable)) {
                setText(mText);
            }
            fixFocusableAndClickableSettings();
            // SelectionModifierCursorController depends on textCanBeSelected, which depends on
            // mMovement
            if (mEditor != null) mEditor.prepareCursorControllers();
        }
    }
    private void fixFocusableAndClickableSettings() {
        if (mMovement != null || (mEditor != null && mEditor.mKeyListener != null)) {
            setFocusable(true);
            setClickable(true);
            setLongClickable(true);
        } else {
            setFocusable(false);
            setClickable(false);
            setLongClickable(false);
        }
    }

可以看到在fixFocusableAndClickableSettings方法里面if(mMovement!=null)时setFocusable、setClickable的值都为true，所以我们需要在setMovementMethod之后再制定这几个值为false。

public class CustomClickMovementMethod extends BaseMovementMethod{

    private static CustomClickMovementMethod sInstance;

    public static CustomClickMovementMethod getInstance(){
        if (sInstance==null){
            sInstance = new CustomClickMovementMethod();
        }
        return sInstance;
    }

    @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;
            } else {
                Selection.removeSelection(buffer);
            }
        }
        return false;
    }

    @Override
    public void initialize(TextView widget, Spannable text) {
        Selection.removeSelection(text);
    }
}

content_text.setMovementMethod(CustomClickMovementMethod.getInstance());
content_text.setFocusable(false);
content_text.setClickable(false);
content_text.setLongClickable(false);

事件接受的顺序是从最外层布局到最内层布局，而事件的响应顺序是从最内层到最外层，事件先从最外层的viewgroup一层一层往最内层，分发如果最内层view不消费再一层一层的返还事件，这是一个haoshi