CodeAssist: Ensure perfect match for keywords

...as otherwise the completion windows stays open and gets in the way.

Fixes: QTCREATORBUG-21767
Change-Id: Ib0a841b9d9de52109439f067c466478744361814
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/clangcodemodel/clangassistproposalitem.cpp

@@ -489,6 +489,12 @@ QString ClangAssistProposalItem::detail() const
     return detail;
 }
 
+bool ClangAssistProposalItem::isKeyword() const
+{
+    // KeywordCompletionKind includes real keywords but also "code patterns"/snippets.
+    return m_codeCompletions[0].completionKind == CodeCompletion::KeywordCompletionKind;
+}
+
 bool ClangAssistProposalItem::isSnippet() const
 {
     return false;

src/plugins/clangcodemodel/clangassistproposalitem.h

@@ -47,6 +47,7 @@ public:
     QString text() const final;
     QIcon icon() const final;
     QString detail() const final;
+    bool isKeyword() const final;
     bool isSnippet() const final;
     bool isValid() const final;
     quint64 hash() const final;

src/plugins/cpptools/cppcompletionassist.cpp

@@ -92,7 +92,10 @@ public:
     void keepCompletionOperator(unsigned compOp) { m_completionOperator = compOp; }
     void keepTypeOfExpression(const QSharedPointer<TypeOfExpression> &typeOfExp)
     { m_typeOfExpression = typeOfExp; }
-
+    bool isKeyword() const final
+    { return m_isKeyword; }
+    void setIsKeyword(bool isKeyword)
+    { m_isKeyword = isKeyword; }
 
     quint64 hash() const override;
 
@@ -101,6 +104,7 @@ private:
     unsigned m_completionOperator = T_EOF_SYMBOL;
     mutable QChar m_typedChar;
     bool m_isOverloaded = false;
+    bool m_isKeyword = false;
 };
 
 } // Internal
@@ -1531,6 +1535,16 @@ bool InternalCppCompletionAssistProcessor::globalCompletion(Scope *currentScope)
     return !m_completions.isEmpty();
 }
 
+void InternalCppCompletionAssistProcessor::addKeywordCompletionItem(const QString &text)
+{
+    auto item = new CppAssistProposalItem;
+    item->setText(text);
+    item->setIcon(Icons::keywordIcon());
+    item->setOrder(KeywordsOrder);
+    item->setIsKeyword(true);
+    m_completions.append(item);
+}
+
 bool InternalCppCompletionAssistProcessor::completeMember(const QList<LookupItem> &baseResults)
 {
     const LookupContext &context = m_model->m_typeOfExpression->context();
@@ -1859,16 +1873,16 @@ void InternalCppCompletionAssistProcessor::addKeywords()
 
     // keyword completion items.
     for (int i = T_FIRST_KEYWORD; i < keywordLimit; ++i)
-        addCompletionItem(QLatin1String(Token::name(i)), Icons::keywordIcon(), KeywordsOrder);
+        addKeywordCompletionItem(QLatin1String(Token::name(i)));
 
     // primitive type completion items.
     for (int i = T_FIRST_PRIMITIVE; i <= T_LAST_PRIMITIVE; ++i)
-        addCompletionItem(QLatin1String(Token::name(i)), Icons::keywordIcon(), KeywordsOrder);
+        addKeywordCompletionItem(QLatin1String(Token::name(i)));
 
     // "Identifiers with special meaning"
     if (m_interface->languageFeatures().cxx11Enabled) {
-        addCompletionItem(QLatin1String("override"), Icons::keywordIcon(), KeywordsOrder);
+        addKeywordCompletionItem(QLatin1String("override"));
-        addCompletionItem(QLatin1String("final"), Icons::keywordIcon(), KeywordsOrder);
+        addKeywordCompletionItem(QLatin1String("final"));
     }
 }
 

src/plugins/cpptools/cppcompletionassist.h

@@ -138,6 +138,7 @@ private:
                                    CPlusPlus::Scope *cursorScope);
     bool globalCompletion(CPlusPlus::Scope *scope);
 
+    void addKeywordCompletionItem(const QString &text);
     void addCompletionItem(const QString &text,
                            const QIcon &icon = QIcon(),
                            int order = 0,

src/plugins/texteditor/codeassist/assistproposaliteminterface.h

@@ -62,6 +62,7 @@ public:
     virtual void apply(TextDocumentManipulatorInterface &manipulator, int basePosition) const = 0;
     virtual QIcon icon() const = 0;
     virtual QString detail() const = 0;
+    virtual bool isKeyword() const { return false; };
     virtual bool isSnippet() const = 0;
     virtual bool isValid() const = 0;
     virtual quint64 hash() const = 0; // it is only for removing duplicates

src/plugins/texteditor/codeassist/genericproposalmodel.cpp

@@ -214,8 +214,13 @@ bool GenericProposalModel::isPerfectMatch(const QString &prefix) const
         if (match == PerfectMatchType::StartsWith)
             return false;
 
-        if (!hasFullMatch && match == PerfectMatchType::Full)
+        if (match == PerfectMatchType::Full) {
-            hasFullMatch = true;
+            if (proposalItem(i)->isKeyword())
+                return true;
+
+            if (!hasFullMatch)
+                hasFullMatch = true;
+        }
     }
 
     return hasFullMatch;