Complete Flutter's setState() as a whole statement, with a closure, a…

…nd the caret inside the closure.

[email protected], [email protected]

Bug: flutter/flutter-intellij#1916
Change-Id: I90b8c11c5435e1981fb334a4762bbe2131f3064f
Reviewed-on: https://dart-review.googlesource.com/48526
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

pkg/analysis_server/lib/src/services/completion/dart/inherited_reference_contributor.dart

@@ -6,6 +6,7 @@ import 'dart:async';
 
 import 'package:analysis_server/src/provisional/completion/dart/completion_dart.dart';
 import 'package:analysis_server/src/services/completion/dart/suggestion_builder.dart';
+import 'package:analysis_server/src/utilities/flutter.dart' as flutter;
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/standard_resolution_map.dart';
 import 'package:analyzer/dart/element/element.dart';
@@ -81,16 +82,17 @@ class InheritedReferenceContributor extends DartCompletionContributor
         skipChildClass: skipChildClass);
   }
 
-  _addSuggestionsForType(InterfaceType type, OpType optype,
+  _addSuggestionsForType(InterfaceType type, DartCompletionRequest request,
       {bool isFunctionalArgument: false}) {
+    OpType opType = request.opType;
     if (!isFunctionalArgument) {
       for (PropertyAccessorElement elem in type.accessors) {
         if (elem.isGetter) {
-          if (optype.includeReturnValueSuggestions) {
+          if (opType.includeReturnValueSuggestions) {
             addSuggestion(elem);
           }
         } else {
-          if (optype.includeVoidReturnSuggestions) {
+          if (opType.includeVoidReturnSuggestions) {
             addSuggestion(elem);
           }
         }
@@ -100,12 +102,13 @@ class InheritedReferenceContributor extends DartCompletionContributor
       if (elem.returnType == null) {
         addSuggestion(elem);
       } else if (!elem.returnType.isVoid) {
-        if (optype.includeReturnValueSuggestions) {
+        if (opType.includeReturnValueSuggestions) {
           addSuggestion(elem);
         }
       } else {
-        if (optype.includeVoidReturnSuggestions) {
-          addSuggestion(elem);
+        if (opType.includeVoidReturnSuggestions) {
+          CompletionSuggestion suggestion = addSuggestion(elem);
+          _updateFlutterSuggestions(request, elem, suggestion);
         }
       }
     }
@@ -118,17 +121,58 @@ class InheritedReferenceContributor extends DartCompletionContributor
     kind = isFunctionalArgument
         ? CompletionSuggestionKind.IDENTIFIER
         : CompletionSuggestionKind.INVOCATION;
-    OpType optype = request.opType;
-
     if (!skipChildClass) {
-      _addSuggestionsForType(classElement.type, optype,
+      _addSuggestionsForType(classElement.type, request,
           isFunctionalArgument: isFunctionalArgument);
     }
 
     for (InterfaceType type in classElement.allSupertypes) {
-      _addSuggestionsForType(type, optype,
+      _addSuggestionsForType(type, request,
           isFunctionalArgument: isFunctionalArgument);
     }
     return suggestions;
   }
+
+  void _updateFlutterSuggestions(DartCompletionRequest request, Element element,
+      CompletionSuggestion suggestion) {
+    if (suggestion == null) {
+      return;
+    }
+    if (element is MethodElement &&
+        element.name == 'setState' &&
+        flutter.isExactState(element.enclosingElement)) {
+      // Find the line indentation.
+      String content = request.result.content;
+      int lineStartOffset = request.offset;
+      int notWhitespaceOffset = request.offset;
+      for (; lineStartOffset > 0; lineStartOffset--) {
+        var char = content.substring(lineStartOffset - 1, lineStartOffset);
+        if (char == '\n') {
+          break;
+        }
+        if (char != ' ' && char != '\t') {
+          notWhitespaceOffset = lineStartOffset - 1;
+        }
+      }
+      String indent = content.substring(lineStartOffset, notWhitespaceOffset);
+
+      // Let the user know that we are going to insert a complete statement.
+      suggestion.displayText = 'setState(() {});';
+
+      // Build the completion and the selection offset.
+      var buffer = new StringBuffer();
+      buffer.writeln('setState(() {');
+      buffer.write('$indent  ');
+      suggestion.selectionOffset = buffer.length;
+      buffer.writeln();
+      buffer.write('$indent});');
+      suggestion.completion = buffer.toString();
+
+      // There are no arguments to fill.
+      suggestion.parameterNames = null;
+      suggestion.parameterTypes = null;
+      suggestion.requiredParameterCount = null;
+      suggestion.hasNamedParameters = null;
+    }
+  }
 }

pkg/analysis_server/lib/src/services/completion/dart/suggestion_builder.dart

@@ -144,13 +144,13 @@ abstract class ElementSuggestionBuilder {
   /**
    * Add a suggestion based upon the given element.
    */
-  void addSuggestion(Element element,
+  CompletionSuggestion addSuggestion(Element element,
       {String prefix,
       int relevance: DART_RELEVANCE_DEFAULT,
       String elementCompletion}) {
     if (element.isPrivate) {
       if (element.library != containingLibrary) {
-        return;
+        return null;
       }
     }
     String completion = elementCompletion ?? element.displayName;
@@ -162,7 +162,7 @@ abstract class ElementSuggestionBuilder {
       }
     }
     if (completion == null || completion.length <= 0) {
-      return;
+      return null;
     }
     CompletionSuggestion suggestion = createSuggestion(element,
         completion: completion, kind: kind, relevance: relevance);
@@ -195,7 +195,7 @@ abstract class ElementSuggestionBuilder {
                 typeParameters: getter.element.typeParameters,
                 parameters: null,
                 returnType: getter.returnType);
-            return;
+            return existingSuggestion;
           }
 
           // Cache lone getter/setter so that it can be paired
@@ -206,6 +206,7 @@ abstract class ElementSuggestionBuilder {
         suggestions.add(suggestion);
       }
     }
+    return suggestion;
   }
 }
 

pkg/analysis_server/lib/src/utilities/flutter.dart

@@ -259,6 +259,11 @@ bool isExactlyStatelessWidgetType(DartType type) {
       _isExactWidget(type.element, _STATELESS_WIDGET_NAME, _WIDGET_URI);
 }
 
+/// Return `true` if the given [element] is the Flutter class `State`.
+bool isExactState(ClassElement element) {
+  return _isExactWidget(element, _STATE_NAME, _WIDGET_URI);
+}
+
 /**
  * Return `true` if the given [type] is the Flutter class `Center`.
  */

pkg/analysis_server/test/services/completion/dart/inherited_reference_contributor_test.dart

@@ -1,6 +1,7 @@
 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
+import 'dart:async';
 
 import 'package:analysis_server/src/protocol_server.dart';
 import 'package:analysis_server/src/provisional/completion/dart/completion_dart.dart';
@@ -125,6 +126,42 @@ class A extends E implements I with M {a() {^}}''');
     assertSuggestMethod('m2', 'M', 'int');
   }
 
+  test_flutter_setState_hasPrefix() async {
+    var spaces_4 = ' ' * 4;
+    var spaces_6 = ' ' * 6;
+    await _check_flutter_setState(
+        '    setSt',
+        '''
+setState(() {
+$spaces_6
+$spaces_4});''',
+        20);
+  }
+
+  test_flutter_setState_longPrefix() async {
+    var spaces_6 = ' ' * 6;
+    var spaces_8 = ' ' * 8;
+    await _check_flutter_setState(
+        '      setSt',
+        '''
+setState(() {
+$spaces_8
+$spaces_6});''',
+        22);
+  }
+
+  test_flutter_setState_noPrefix() async {
+    var spaces_4 = ' ' * 4;
+    var spaces_6 = ' ' * 6;
+    await _check_flutter_setState(
+        '    ',
+        '''
+setState(() {
+$spaces_6
+$spaces_4});''',
+        20);
+  }
+
   test_inherited() async {
     resolveSource('/testB.dart', '''
 lib libB;
@@ -604,4 +641,37 @@ class B extends A1 with A2 {
     assertNotSuggested('x2');
     assertNotSuggested('y2');
   }
+
+  Future<void> _check_flutter_setState(
+      String line, String completion, int selectionOffset) async {
+    addFlutterPackage();
+    addTestSource('''
+import 'package:flutter/widgets.dart';
+
+class TestWidget extends StatefulWidget {
+  @override
+  TestWidgetState createState() {
+    return new TestWidgetState();
+  }
+}
+
+class TestWidgetState extends State<TestWidget> {
+  @override
+  Widget build(BuildContext context) {
+$line^
+  }
+}
+''');
+    await computeSuggestions();
+    CompletionSuggestion cs =
+        assertSuggest(completion, selectionOffset: selectionOffset);
+    expect(cs.selectionLength, 0);
+
+    // It is an invocation, but we don't need any additional info for it.
+    // So, all parameter information is absent.
+    expect(cs.parameterNames, isNull);
+    expect(cs.parameterTypes, isNull);
+    expect(cs.requiredParameterCount, isNull);
+    expect(cs.hasNamedParameters, isNull);
+  }
 }