Я хочу прослушать ScrollView, чтобы увидеть, прокручивается ли он. Я использовал OnTouchListener, он работает хорошо. Но когда я хочу добавить совместимость с трекболом, используя OnKeyListener или переопределяя метод OnKeydown, это не сработает. Похоже, что дочерние кнопки, принимающие фокус, вызывают проблему.
Любое решение или обходной путь для решения этой проблемы? Любая помощь приветствуется.
Вот несколько демонстрационных кодов для воспроизведения моей проблемы:
public class TestActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
ScrollView scrollView = (ScrollView) findViewById(R.id.scroll_view);
LinearLayout mainLayout = (LinearLayout) findViewById(R.id.main_layout);
LinearLayout.LayoutParams wrapParams = new LinearLayout.LayoutParams(
ViewGroup.LayoutParams.FILL_PARENT,
ViewGroup.LayoutParams.WRAP_CONTENT);
for (int i = 0; i < 100; i++) {
MyItem item = (MyItem) LayoutInflater.from(this).inflate(R.layout.item, null);
item.setParent(scrollView);
item.setBackgroundColor(Color.WHITE);
item.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,
LayoutParams.WRAP_CONTENT));
mainLayout.addView(item, wrapParams);
}
scrollView.setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
// can go into here
}
});
scrollView.setOnKeyListener(new OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_DPAD_DOWN || keyCode == KeyEvent.KEYCODE_DPAD_DOWN) {
// never go in, unless no child button get focus
}
return false;
}
});
}
}
main.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<com.fannyxie.MyScroller
android:id="@+id/scroll_view"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:descendantFocusability="beforeDescendants"
android:clickable="true"
android:focusable="true">
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<LinearLayout android:id="@+id/main_layout"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
</LinearLayout>
</LinearLayout>
</com.fannyxie.MyScroller>
</LinearLayout>
item.xml:
<?xml version="1.0" encoding="utf-8"?>
<com.fannyxie.MyItem xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="TITLE"/>
<Button android:layout_width="wrap_content" android:layout_height="wrap_content"
android:id="@+id/myButton" android:text="Button"></Button>
</com.fannyxie.MyItem>
MyScroller.java
public class MyScroller extends ScrollView {
public MyScroller(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
//not go into here...
Log.i("MyScroller", "onKeyDown");
return super.onKeyDown(keyCode, event);
}
@Override
public boolean onTrackballEvent(MotionEvent event) {
//not go into here...
Log.i("MyScroller", "onTrackballEvent");
return super.onTrackballEvent(event);
}
@Override
protected boolean onRequestFocusInDescendants(int direction,
Rect previouslyFocusedRect) {
//some times go into here, when no button get the focus when entering first time
Log.i("MyScroller", "request focus in descendants");
return super.onRequestFocusInDescendants(direction, previouslyFocusedRect);
}
}
MyItem.java
public class MyItem extends LinearLayout {
private Button myButton;
public MyItem(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
protected boolean onRequestFocusInDescendants(int direction,
Rect previouslyFocusedRect) {
// never go into here
Log.i("MyItem", "request focus in descendants");
return super.onRequestFocusInDescendants(direction, previouslyFocusedRect);
}
}