Change all ocurrences of '$runtimeType#$hashCode' to use the idAndType method. (flutter#10871)

* Change all instances of '$runtimeType#$hashCode' to use the describeIdentity method.

The describeIdentity method generates a shorter description with a consistent length
consisting of the runtime type and the a 5 hex character long truncated
version of the hash code.

Author: jacob314

packages/flutter/lib/src/animation/animation.dart

@@ -81,7 +81,7 @@ abstract class Animation<T> extends Listenable {
 
   @override
   String toString() {
-    return '$runtimeType#$hashCode(${toStringDetails()})';
+    return '${describeIdentity(this)}(${toStringDetails()})';
   }
 
   /// Provides a string describing the status of this object, but not including

packages/flutter/lib/src/foundation/change_notifier.dart

@@ -7,6 +7,7 @@ import 'package:meta/meta.dart';
 import 'assertions.dart';
 import 'basic_types.dart';
 import 'observer_list.dart';
+import 'print.dart';
 
 /// An object that maintains a list of listeners.
 abstract class Listenable {
@@ -185,5 +186,5 @@ class ValueNotifier<T> extends ChangeNotifier {
   }
 
   @override
-  String toString() => '$runtimeType#$hashCode($value)';
+  String toString() => '${idAndType(this)}($value)';
 }

packages/flutter/lib/src/foundation/tree_diagnostics_mixin.dart

@@ -6,6 +6,15 @@ import 'package:meta/meta.dart';
 
 import 'print.dart';
 
+/// Returns a 5 character long hexadecimal hash code for [object].
+String shortHash(Object object) {
+  return object.hashCode.toUnsigned(20).toRadixString(16).padLeft(5, '0');
+}
+
+/// Returns a summary of [object]'s runtime type and hash code.
+String describeIdentity(Object object) =>
+    '${object.runtimeType}#${shortHash(object)}';
+
 /// A mixin that helps dump string representations of trees.
 abstract class TreeDiagnosticsMixin {
   // This class is intended to be used as a mixin, and should not be
@@ -20,7 +29,7 @@ abstract class TreeDiagnosticsMixin {
   ///  * [toStringShallow], for a detailed description of the object.
   ///  * [toStringDeep], for a description of the subtree rooted at this object.
   @override
-  String toString() => '$runtimeType#$hashCode';
+  String toString() => describeIdentity(this);
 
   /// Returns a one-line detailed description of the object.
   ///

packages/flutter/lib/src/gestures/recognizer.dart

@@ -86,7 +86,7 @@ abstract class GestureRecognizer extends GestureArenaMember {
   }
 
   @override
-  String toString() => '$runtimeType#$hashCode';
+  String toString() => describeIdentity(this);
 }
 
 /// Base class for gesture recognizers that can only recognize one
@@ -321,5 +321,5 @@ abstract class PrimaryPointerGestureRecognizer extends OneSequenceGestureRecogni
   }
 
   @override
-  String toString() => '$runtimeType#$hashCode($state)';
+  String toString() => '${describeIdentity(this)}($state)';
 }

packages/flutter/lib/src/material/app_bar.dart

@@ -604,7 +604,7 @@ class _SliverAppBarDelegate extends SliverPersistentHeaderDelegate {
 
   @override
   String toString() {
-    return '$runtimeType#$hashCode(topPadding: ${topPadding.toStringAsFixed(1)}, bottomHeight: ${_bottomHeight.toStringAsFixed(1)}, ...)';
+    return '${describeIdentity(this)}(topPadding: ${topPadding.toStringAsFixed(1)}, bottomHeight: ${_bottomHeight.toStringAsFixed(1)}, ...)';
   }
 }
 

packages/flutter/lib/src/material/material.dart

@@ -425,5 +425,5 @@ abstract class InkFeature {
   void paintFeature(Canvas canvas, Matrix4 transform);
 
   @override
-  String toString() => '$runtimeType#$hashCode';
+  String toString() => describeIdentity(this);
 }

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

@@ -572,7 +572,7 @@ class BoxHitTestEntry extends HitTestEntry {
   final Offset localPosition;
 
   @override
-  String toString() => '${target.runtimeType}#${target.hashCode}@$localPosition';
+  String toString() => '${describeIdentity(target)}@$localPosition';
 }
 
 /// Parent data used by [RenderBox] and its subclasses.

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

@@ -636,7 +636,7 @@ abstract class _SemanticsFragment {
   Iterable<SemanticsNode> compile({ _SemanticsGeometry geometry, SemanticsNode currentSemantics, SemanticsNode parentSemantics });
 
   @override
-  String toString() => '$runtimeType#$hashCode';
+  String toString() => describeIdentity(this);
 }
 
 /// A SemanticsFragment that doesn't produce any [SemanticsNode]s when compiled.
@@ -2686,7 +2686,7 @@ abstract class RenderObject extends AbstractNode implements HitTestTarget {
   /// Returns a human understandable name.
   @override
   String toString() {
-    String header = '$runtimeType#$hashCode';
+    String header = describeIdentity(this);
     if (_relayoutBoundary != null && _relayoutBoundary != this) {
       int count = 1;
       RenderObject target = parent;

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

@@ -2034,7 +2034,7 @@ abstract class CustomPainter extends Listenable {
   bool hitTest(Offset position) => null;
 
   @override
-  String toString() => '$runtimeType#$hashCode(${ _repaint?.toString() ?? "" })';
+  String toString() => '${describeIdentity(this)}(${ _repaint?.toString() ?? "" })';
 }
 
 /// Provides a canvas on which to draw during the paint phase.

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

@@ -781,5 +781,5 @@ class SemanticsOwner extends ChangeNotifier {
   }
 
   @override
-  String toString() => '$runtimeType#$hashCode';
+  String toString() => describeIdentity(this);
 }