因此,我正在制作一个简单的Android上的待办事项列表应用程序,并尝试使事情变得更棘手。
我要开始工作的一件事是detecting swipes
。现在,我希望能够检测到放置在swipe on a TextView
内的linear layout
。这种线性布局是一个RecyclingView item
的视图持有者。
令我困惑的是,检测到onDown和onScroll但未检测到onFling。
这是我的代码
class ViewHolder extends RecyclerView.ViewHolder {
public TextView toDoText;
public Button checkButton;
public ViewHolder(View itemView){
super(itemView);
toDoText = itemView.findViewById(R.id.toDoText);
checkButton = itemView.findViewById(R.id.checkButton);
}
}
class ToDoAdapter extends RecyclerView.Adapter<ViewHolder> {
List<String> toDos;
public ToDoAdapter(List<String> toDos){
this.toDos = toDos;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int id){
Context context = parent.getContext();
LayoutInflater inflater = LayoutInflater.from(context);
View toDoView = inflater.inflate(R.layout.to_do_row, parent, false);
ViewHolder viewHolder = new ViewHolder(toDoView);
return viewHolder;
}
@SuppressLint("ClickableViewAccessibility")
@Override
public void onBindViewHolder(ViewHolder viewHolder, final int position){
String toDo = toDos.get(position);
final TextView textView = viewHolder.toDoText;
textView.setText(toDo);
textView.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
GestureDetector detector;
GestureDetector.OnGestureListener listener = new GestureDetector.OnGestureListener() {
@Override
public boolean onDown(MotionEvent e) {
System.out.println("DOWN");
return true;
}
@Override
public void onShowPress(MotionEvent e) {
System.out.println("SHOW PRESS");
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
System.out.println("SINGLE TAP UP");
return true;
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
System.out.println("SCROLL");
return true;
}
@Override
public void onLongPress(MotionEvent e) {
System.out.println("LONG PRESS");
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
System.out.println("FLING");
return true;
}
};
detector = new GestureDetector(listener);
detector.setIsLongpressEnabled(false);
return detector.onTouchEvent(event);
}
});
Button button = viewHolder.checkButton;
button.setEnabled(true);
button.setText("Check");
button.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v) {
toDos.remove(position);
ToDoAdapter.this.notifyItemRemoved(position);
notifyItemRangeChanged(position, toDos.size());
}
});
}
@Override
public int getItemCount(){
return toDos.size();
}
}
public class MainActivity extends AppCompatActivity {
ArrayList<String> items;
RecyclerView rvItems;
EditText editText;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
rvItems = findViewById(R.id.itemListRecycler);
items = new ArrayList<>();
items.add("Test this todo out");
final ToDoAdapter adapter = new ToDoAdapter(items);
rvItems.setAdapter(adapter);
final RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(this);
rvItems.setLayoutManager(layoutManager);
Button addItem = findViewById(R.id.addNewItemButton);
editText = findViewById(R.id.newItemText);
addItem.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
String input = editText.getText().toString();
if(input == null) {
input = "";
}
items.add(input);
adapter.notifyItemInserted(items.size()-1);
layoutManager.scrollToPosition(items.size()-1);
}
});
}
}
这是我主要活动的XML
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:id="@+id/addNewItemButton"
android:layout_width="wrap_content"
android:layout_height="0dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="16dp"
android:layout_marginRight="16dp"
android:layout_marginBottom="16dp"
android:text="Add Item"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toEndOf="@+id/newItemText"
app:layout_constraintTop_toBottomOf="@+id/itemListRecycler"
app:layout_constraintVertical_bias="1.0" />
<EditText
android:id="@+id/newItemText"
android:layout_width="0dp"
android:layout_height="44dp"
android:layout_marginStart="16dp"
android:layout_marginLeft="16dp"
android:layout_marginEnd="16dp"
android:layout_marginRight="16dp"
android:layout_marginBottom="16dp"
android:ems="10"
android:inputType="textPersonName"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="@+id/addNewItemButton"
app:layout_constraintStart_toStartOf="parent" />
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/itemListRecycler"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginStart="16dp"
android:layout_marginLeft="16dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="16dp"
android:layout_marginRight="16dp"
android:layout_marginBottom="16dp"
android:scrollbars="vertical"
app:layout_constraintBottom_toTopOf="@+id/newItemText"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0" />
</androidx.constraintlayout.widget.ConstraintLayout>
这是线性布局的XML
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal"
android:layout_width="match_parent"
android:id="@+id/toDoItemLayout"
android:layout_height="wrap_content"
android:paddingTop="10dp"
android:paddingBottom="10dp"
>
<TextView
android:id="@+id/toDoText"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:textSize="20dp"/>
<Button
android:id="@+id/checkButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingLeft="16dp"
android:paddingRight="16dp"
android:textSize="10sp"
/>
</LinearLayout>
最佳答案
原来,您必须像这样在onTouchListener的匿名子类外移动GestureListener和detector的初始化
public void onBindViewHolder(ViewHolder viewHolder, final int position){
String toDo = toDos.get(position);
final TextView textView = viewHolder.toDoText;
textView.setText(toDo);
final GestureDetector detector;
final GestureDetector.OnGestureListener listener = new GestureDetector.OnGestureListener() {
@Override
public boolean onDown(MotionEvent e) {
System.out.println("DOWN");
return true;
}
@Override
public void onShowPress(MotionEvent e) {
System.out.println("SHOW PRESS");
}
@Override
public boolean onSingleTapUp(MotionEvent e) {
System.out.println("SINGLE TAP UP");
return true;
}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
System.out.println("SCROLL");
return true;
}
@Override
public void onLongPress(MotionEvent e) {
System.out.println("LONG PRESS");
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
System.out.println("FLING");
return true;
}
};
detector = new GestureDetector(listener);
detector.setIsLongpressEnabled(false);
textView.setOnTouchListener(new View.OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
return detector.onTouchEvent(event);
}
});
Button button = viewHolder.checkButton;
button.setEnabled(true);
button.setText("Check");
button.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v) {
toDos.remove(position);
ToDoAdapter.this.notifyItemRemoved(position);
notifyItemRangeChanged(position, toDos.size());
}
});
}