Поместите пользовательский чертежный вид (холст) внутри класса, который расширяет фрагмент

Question

Мне нужно создать «страницу», где я могу рисовать пальцем. Я нашел, как это сделать в stackoverflow, но я не хочу создавать новую активность, я хочу сделать так, как показано ниже, возможно ли это?

Компоновка класса, который расширяет frament:

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="match_parent" 
android:layout_height="wrap_content" 
xmlns:app="http://schemas.android.com/apk/res-auto" 
android:orientation="vertical"> 

<android.support.v7.widget.CardView 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:card_view="http://schemas.android.com/apk/res-auto" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:layout_gravity="center" 
    android:layout_margin="8dp" 
    card_view:cardCornerRadius="4dp"> 
    <EditText 
     android:id="@+id/note_draw_titolo" 
     android:layout_width="match_parent" 
     android:layout_height="?attr/listPreferredItemHeight" 
     android:gravity="center_vertical" 
     android:padding="8dp" 
     android:hint="Titolo" 
     android:textAlignment="center" 
     android:textStyle="bold" 
     style="@style/Base.TextAppearance.AppCompat.Body2"/> 
</android.support.v7.widget.CardView> 

<RelativeLayout 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:layout_margin="8dp"> 
    <com.marcocreation.********.DrawingView 
     android:id="@+id/drawView" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:background="#ffffff" 
     android:visibility="visible" 
     android:layout_alignParentBottom="true"> 
    </com.marcocreation.*******.DrawingView> 
</RelativeLayout> 

Drawingview класс:

public class DrawingView extends View { 

public int width; 
public int height; 
private Bitmap mBitmap; 
private Canvas mCanvas; 
private Path mPath; 
private Paint mBitmapPaint; 
Context context; 
private Paint circlePaint; 
private Path circlePath; 
private Paint mPaint; 

public DrawingView(Context c, AttributeSet attrs, int defStyle) { 
    super(c, attrs, defStyle); 
    context=c; 
    mPath = new Path(); 
    mBitmapPaint = new Paint(Paint.DITHER_FLAG); 
    circlePaint = new Paint(); 
    circlePath = new Path(); 
    circlePaint.setAntiAlias(true); 
    circlePaint.setColor(Color.BLUE); 
    circlePaint.setStyle(Paint.Style.STROKE); 
    circlePaint.setStrokeJoin(Paint.Join.MITER); 
    circlePaint.setStrokeWidth(4f); 
    initPaint(); 
} 

protected void initPaint(){ 
    mPaint = new Paint(); 
    mPaint.setAntiAlias(true); 
    mPaint.setDither(true); 
    mPaint.setColor(Color.GREEN); 
    mPaint.setStyle(Paint.Style.STROKE); 
    mPaint.setStrokeJoin(Paint.Join.ROUND); 
    mPaint.setStrokeCap(Paint.Cap.ROUND); 
    mPaint.setStrokeWidth(12); 
} 

@Override 
protected void onSizeChanged(int w, int h, int oldw, int oldh) { 
    super.onSizeChanged(w, h, oldw, oldh); 

    mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888); 
    mCanvas = new Canvas(mBitmap); 
} 

@Override 
protected void onDraw(Canvas canvas) { 
    super.onDraw(canvas); 

    canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint); 
    canvas.drawPath(mPath, mPaint); 
    canvas.drawPath(circlePath, circlePaint); 
} 

private float mX, mY; 
private static final float TOUCH_TOLERANCE = 4; 

private void touch_start(float x, float y) { 
    mPath.reset(); 
    mPath.moveTo(x, y); 
    mX = x; 
    mY = y; 
} 

private void touch_move(float x, float y) { 
    float dx = Math.abs(x - mX); 
    float dy = Math.abs(y - mY); 
    if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) { 
     mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2); 
     mX = x; 
     mY = y; 

     circlePath.reset(); 
     circlePath.addCircle(mX, mY, 30, Path.Direction.CW); 
    } 
} 

private void touch_up() { 
    mPath.lineTo(mX, mY); 
    circlePath.reset(); 
    // commit the path to our offscreen 
    mCanvas.drawPath(mPath, mPaint); 
    // kill this so we don't double draw 
    mPath.reset(); 
} 

@Override 
public boolean onTouchEvent(MotionEvent event) { 
    float x = event.getX(); 
    float y = event.getY(); 

    switch (event.getAction()) { 
     case MotionEvent.ACTION_DOWN: 
      touch_start(x, y); 
      invalidate(); 
      break; 
     case MotionEvent.ACTION_MOVE: 
      touch_move(x, y); 
      invalidate(); 
      break; 
     case MotionEvent.ACTION_UP: 
      touch_up(); 
      invalidate(); 
      break; 
    } 
    return true; 
} 
} 

И в customFragment я все начинать с:

public class NoteFragment extends Fragment { 

private EditText sharedTitolo; 
private EditText sharedNota; 
private NoteDataSource notesource; 
private TextView recordTimeText; 
private ImageButton audioSendButton; 
private View recordPanel; 
private View slideText; 
private Context context; 
private DrawingView drawView; 

public static NoteFragment createInstance(int index, int tipo, Context c) { 
    NoteFragment noteFragment = new NoteFragment(c); 
    Bundle bundle = new Bundle(); 
    ... 
    return noteFragment; 
} 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 

} 

@SuppressLint("ValidFragment") 
public NoteFragment (Context c){ 
    this.context = c; 
} 


@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
    View view = null; 
    Bundle bundle = getArguments(); 
    switch (bundle.getInt("type")){ 
     case 1: 
      ... 
      break; 
     case 2: 
      view = (View) inflater.inflate(R.layout.note_draw_layout, container, false); 
      sharedTitolo = (EditText)view.findViewById(R.id.note_draw_titolo); 
      drawView = (DrawingView)view.findViewById(R.id.drawView); 
      if(bundle.getInt("index")>0){ 
       Log.i("nf_indice",""+bundle.getInt("index")); 
       sharedTitolo.setText("text"); 
      } 
      else{ 
       ... 
      } 
      break; 
     case 3: 
      ... 
      break; 
     default: 
      break; 
    } 

    return view; 
} 
} 

Но я получить эту ошибку:

android.view.InflateException: Binary XML file line #32: Binary XML file line #32: Error inflating class com.marcocreation.******.DrawingView 

пс Notefragment запускается класс, расширяющий appcompactactivity и создал FragmentPagerAdapter, и имеет компоновку координаторов.

Полный журнал ошибок:

07-24 11:03:44.805 29830-29830/com.marcocreation.******* E/AndroidRuntime: FATAL EXCEPTION: main 
                      Process: com.marcocreation.*******, PID: 29830 
                      android.view.InflateException: Binary XML file line #28: Binary XML file line #28: Error inflating class com.marcocreation.*******.DrawingView 
                       at android.view.LayoutInflater.inflate(LayoutInflater.java:539) 
                       at android.view.LayoutInflater.inflate(LayoutInflater.java:423) 
                       at com.marcocreation.*******.NoteFragment.onCreateView(NoteFragment.java:86) 
                       at android.support.v4.app.Fragment.performCreateView(Fragment.java:2074) 
                       at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104) 
                       at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1286) 
                       at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:758) 
                       at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:1632) 
                       at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:637) 
                       at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:143) 
                       at android.support.v4.view.ViewPager.populate(ViewPager.java:1235) 
                       at android.support.v4.view.ViewPager.populate(ViewPager.java:1083) 
                       at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1609) 
                       at android.view.View.measure(View.java:18794) 
                       at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951) 
                       at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:669) 
                       at android.support.design.widget.HeaderScrollingViewBehavior.onMeasureChild(HeaderScrollingViewBehavior.java:89) 
                       at android.support.design.widget.AppBarLayout$ScrollingViewBehavior.onMeasureChild(AppBarLayout.java:1319) 
                       at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:734) 
                       at android.view.View.measure(View.java:18794) 
                       at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951) 
                       at android.support.design.widget.CoordinatorLayout.onMeasureChild(CoordinatorLayout.java:669) 
                       at android.support.design.widget.CoordinatorLayout.onMeasure(CoordinatorLayout.java:736) 
                       at android.view.View.measure(View.java:18794) 
                       at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951) 
                       at android.widget.FrameLayout.onMeasure(FrameLayout.java:194) 
                       at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:135) 
                       at android.view.View.measure(View.java:18794) 
                       at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951) 
                       at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465) 
                       at android.widget.LinearLayout.measureVertical(LinearLayout.java:748) 
                       at android.widget.LinearLayout.onMeasure(LinearLayout.java:630) 
                       at android.view.View.measure(View.java:18794) 
                       at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951) 
                       at android.widget.FrameLayout.onMeasure(FrameLayout.java:194) 
                       at android.view.View.measure(View.java:18794) 
                       at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951) 
                       at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1465) 
                       at android.widget.LinearLayout.measureVertical(LinearLayout.java:748) 
                       at android.widget.LinearLayout.onMeasure(LinearLayout.java:630) 
                       at android.view.View.measure(View.java:18794) 
                       at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5951) 
                       at android.widget.FrameLayout.onMeasure(FrameLayout.java:194) 
                       at com.android.internal.policy.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2643) 
                       at android.view.View.measure(View.java:18794) 
                       at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2100) 
                       at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1216) 
                       at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1452) 
                       at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1107) 
                       at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6013) 
                       at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858) 
                       at android.view.Choreographer.doCallbacks(Choreographer.java:670) 
                       at android.view.Choreographer.doFrame(Choreographer.java:606) 

Answer 1

Для дальнейшего использования, здесь это решение, которое работало.

Конструктор View, который вызывается во время инфляции, равен View(Context context, AttributeSet attrs), однако такой конструктор не указан в DrawingView выше. Таким образом, система Android не смогла раздуть файл макета, поскольку он не смог найти соответствующий конструктор.

Следующая DrawingView конструкторы должны решить вопрос:

// Constructor called during inflation 
public DrawingView(Context c, AttributeSet attrs) { 
    this(c, attrs, 0); 
} 

public DrawingView(Context c, AttributeSet attrs, int defStyle) { 
    super(c, attrs, defStyle); 
    // ... 
}