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我正在开发一个适用于visual disabilities. 如果设备有一个Android API大于 14 我想增强Talkback一下。

ListView填满了整个屏幕,每一行只有一个TextView. 由于文本可能很长,我想marquee在用户单击文本时使用单行来滚动文本。

我在没有的情况下对其进行了测试,并且Talkback可以正常工作:

选框作品

所以我决定用 Talkback active测试它。在这种情况下,我有两种问题:

1- 有些行根本不滚动。

2-有些行滚动,但我看不到比不滚动文本时显示的文本更多的文本:

选框不起作用

我不知道为什么有些行滚动而有些不滚动,我对所有行都使用相同的代码。

要更改背景颜色并启动选取框,我将AccessibilityDelegate在每一行添加一个。

这是每一行的布局:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" >

    <TextView
        android:id="@+id/rowTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:layout_marginLeft="10dp"
        android:layout_marginRight="10dp"
        android:ellipsize="marquee"
        android:marqueeRepeatLimit="marquee_forever"
        android:singleLine="true"
        android:textSize="18dp" />

</LinearLayout>

这是我的适配器的一些代码:

@Override
public View getView(int position, View convertView, ViewGroup parent) {

    if(convertView == null){ // If the View is not cached
        // Inflates the Common View from XML file
        convertView = this.inflater.inflate(R.layout.list_simple_row, parent, false);
    }

    TextView tv = (TextView) convertView.findViewById(R.id.rowTextView);
    tv.setText( list.get(position) );
    convertView.setContentDescription( list.get(position) );

    addAccessibilityDelegate(tv, position); // Add delegate to the TextView to detect touches

    tv.setSingleLine(true);

    if(position == selected){

        // The user touched this row: Change background color to green. 

        convertView.setBackgroundColor(Color.GREEN);
        tv.setTextColor(Color.BLACK);
        tv.setSelected(true);

    }
    else{

        convertView.setBackgroundColor(Color.TRANSPARENT);
        tv.setTextColor(Color.WHITE);
        tv.setSelected(false);

    }

    return convertView;
}

protected void addAccessibilityDelegate( View v, final int position ){

    v.setAccessibilityDelegate(new AccessibilityDelegate(){
        @Override
        public void onInitializeAccessibilityEvent(View host, AccessibilityEvent event) {
            super.onInitializeAccessibilityEvent(host, event);
        }

        @Override
        public void onInitializeAccessibilityNodeInfo(View host,
                AccessibilityNodeInfo info) {
            super.onInitializeAccessibilityNodeInfo(host, info);
        }

        @Override
        public void onPopulateAccessibilityEvent(View host, AccessibilityEvent event) {
            super.onPopulateAccessibilityEvent(host, event);

            if(event.getEventType() == AccessibilityEvent.TYPE_VIEW_HOVER_ENTER){
                focusBackground(position);
            }
        }
    });     
}

public void focusBackground(int position){

    if(selected != position){
        selected = position;
        notifyDataSetInvalidated();
    }
}

有人知道我是否可以在 Talkback 中使用选框吗?

谢谢!

4

1 回答 1

1

Check out this bug on the Android bug tracker, it looks like Accessibility services interfere with the ellipsize property on TextViews. I was having similar issues with android:ellipsize="start" jumping to the start of the string until I disabled the LastPass Accessibility service. I verified that the Talkback service caused the same issue.

于 2014-07-21T04:38:17.107 回答