More detailed debugging info for RenderPointerListener et al

Elaborate on the debugging information exposed by
RenderPointerListener, Listener, and GestureDetector.

packages/flutter/lib/src/rendering/proxy_box.dart

@@ -1038,8 +1038,17 @@ class RenderPointerListener extends RenderProxyBox {
     if (listeners.isEmpty)
       listeners.add('<none>');
     settings.add('listeners: ${listeners.join(", ")}');
-    if (behavior != HitTestBehavior.deferToChild)
-      settings.add('behavior: $behavior');
+    switch (behavior) {
+      case HitTestBehavior.translucent:
+        settings.add('behavior: translucent');
+        break;
+      case HitTestBehavior.opaque:
+        settings.add('behavior: opaque');
+        break;
+      case HitTestBehavior.deferToChild:
+        settings.add('behavior: defer-to-child');
+        break;
+    }
   }
 }
 

packages/flutter/lib/src/widgets/basic.dart

@@ -1258,6 +1258,33 @@ class Listener extends OneChildRenderObjectWidget {
     renderObject.onPointerCancel = onPointerCancel;
     renderObject.behavior = behavior;
   }
+
+  void debugFillDescription(List<String> description) {
+    super.debugFillDescription(description);
+    List<String> listeners = <String>[];
+    if (onPointerDown != null)
+      listeners.add('down');
+    if (onPointerMove != null)
+      listeners.add('move');
+    if (onPointerUp != null)
+      listeners.add('up');
+    if (onPointerCancel != null)
+      listeners.add('cancel');
+    if (listeners.isEmpty)
+      listeners.add('<none>');
+    description.add('listeners: ${listeners.join(", ")}');
+    switch (behavior) {
+      case HitTestBehavior.translucent:
+        description.add('behavior: translucent');
+        break;
+      case HitTestBehavior.opaque:
+        description.add('behavior: opaque');
+        break;
+      case HitTestBehavior.deferToChild:
+        description.add('behavior: defer-to-child');
+        break;
+    }
+  }
 }
 
 class IgnorePointer extends OneChildRenderObjectWidget {

packages/flutter/lib/src/widgets/gesture_detector.dart

@@ -259,5 +259,16 @@ class _GestureDetectorState extends State<GestureDetector> {
     if (gestures.isEmpty)
       gestures.add('<none>');
     description.add('gestures: ${gestures.join(", ")}');
+    switch (config.behavior) {
+      case HitTestBehavior.translucent:
+        description.add('behavior: translucent');
+        break;
+      case HitTestBehavior.opaque:
+        description.add('behavior: opaque');
+        break;
+      case HitTestBehavior.deferToChild:
+        description.add('behavior: defer-to-child');
+        break;
+    }
   }
 }