Widget.paint() must call super

@@ -57,6 +57,12 @@ class LimitedBox extends SingleChildWidget {
     }
     box = PdfRect.fromPoints(PdfPoint.zero, size);
   }
+
+  @override
+  void paint(Context context) {
+    super.paint(context);
+    paintChild(context);
+  }
 }
 
 class Padding extends SingleChildWidget {
@@ -101,12 +107,7 @@ class Padding extends SingleChildWidget {
 
   @override
   void paint(Context context) {
-    assert(() {
-      if (Document.debug) {
-        debugPaint(context);
-      }
-      return true;
-    }());
+    super.paint(context);
 
     if (child != null) {
       final Matrix4 mat = Matrix4.identity();
@@ -191,12 +192,7 @@ class Transform extends SingleChildWidget {
 
   @override
   void paint(Context context) {
-    assert(() {
-      if (Document.debug) {
-        debugPaint(context);
-      }
-      return true;
-    }());
+    super.paint(context);
 
     if (child != null) {
       final Matrix4 mat = _effectiveTransform;
@@ -258,6 +254,12 @@ class Align extends SingleChildWidget {
           height: shrinkWrapHeight ? 0.0 : double.infinity);
     }
   }
+
+  @override
+  void paint(Context context) {
+    super.paint(context);
+    paintChild(context);
+  }
 }
 
 /// A widget that imposes additional constraints on its child.
@@ -282,6 +284,12 @@ class ConstrainedBox extends SingleChildWidget {
           this.constraints.enforce(constraints).constrain(PdfPoint.zero));
     }
   }
+
+  @override
+  void paint(Context context) {
+    super.paint(context);
+    paintChild(context);
+  }
 }
 
 class Center extends Align {
@@ -323,6 +331,8 @@ class FittedBox extends SingleChildWidget {
 
   @override
   void paint(Context context) {
+    super.paint(context);
+
     if (child != null) {
       final PdfPoint childSize = child.box.size;
       final FittedSizes sizes = applyBoxFit(fit, childSize, box.size);
@@ -404,6 +414,12 @@ class AspectRatio extends SingleChildWidget {
           BoxConstraints.tightFor(width: box.width, height: box.height));
     assert(child.box != null);
   }
+
+  @override
+  void paint(Context context) {
+    super.paint(context);
+    paintChild(context);
+  }
 }
 
 typedef CustomPainter = Function(PdfGraphics canvas, PdfPoint size);
@@ -435,12 +451,7 @@ class CustomPaint extends SingleChildWidget {
 
   @override
   void paint(Context context) {
-    assert(() {
-      if (Document.debug) {
-        debugPaint(context);
-      }
-      return true;
-    }());
+    super.paint(context);
 
     final Matrix4 mat = Matrix4.identity();
     mat.translate(box.x, box.y);

@@ -29,12 +29,7 @@ class ClipRect extends SingleChildWidget {
 
   @override
   void paint(Context context) {
-    assert(() {
-      if (Document.debug) {
-        debugPaint(context);
-      }
-      return true;
-    }());
+    super.paint(context);
 
     if (child != null) {
       final Matrix4 mat = Matrix4.identity();
@@ -71,12 +66,7 @@ class ClipRRect extends SingleChildWidget {
 
   @override
   void paint(Context context) {
-    assert(() {
-      if (Document.debug) {
-        debugPaint(context);
-      }
-      return true;
-    }());
+    super.paint(context);
 
     if (child != null) {
       final Matrix4 mat = Matrix4.identity();
@@ -109,12 +99,7 @@ class ClipOval extends SingleChildWidget {
 
   @override
   void paint(Context context) {
-    assert(() {
-      if (Document.debug) {
-        debugPaint(context);
-      }
-      return true;
-    }());
+    super.paint(context);
 
     final double rx = box.width / 2.0;
     final double ry = box.height / 2.0;

@@ -147,11 +147,12 @@ class DecoratedBox extends SingleChildWidget {
 
   @override
   void paint(Context context) {
+    super.paint(context);
     if (position == DecorationPosition.background) {
       decoration.paintBackground(context, box);
       decoration.border?.paintBorders(context, box);
     }
-    super.paint(context);
+    paintChild(context);
     if (position == DecorationPosition.foreground) {
       decoration.paintBackground(context, box);
       decoration.border?.paintBorders(context, box);

@@ -506,6 +506,12 @@ class Expanded extends SingleChildWidget {
   final int flex;
 
   final FlexFit fit;
+
+  @override
+  void paint(Context context) {
+    super.paint(context);
+    paintChild(context);
+  }
 }
 
 class ListView extends Flex {

@@ -44,6 +44,12 @@ class Positioned extends SingleChildWidget {
   double get width => box?.width;
 
   double get height => box?.height;
+
+  @override
+  void paint(Context context) {
+    super.paint(context);
+    paintChild(context);
+  }
 }
 
 /// A widget that positions its children relative to the edges of its box.

@@ -74,6 +74,7 @@ abstract class Widget {
   /// Draw itself and its children, according to the calculated
   /// [box.offset]
   @protected
+  @mustCallSuper
   void paint(Context context) {
     assert(() {
       if (Document.debug) {
@@ -147,10 +148,8 @@ abstract class SingleChildWidget extends Widget {
     }
   }
 
-  @override
-  void paint(Context context) {
-    super.paint(context);
-
+  @protected
+  void paintChild(Context context) {
     if (child != null) {
       final Matrix4 mat = Matrix4.identity();
       mat.translate(box.x, box.y);