Open type hierarchy from Type Hierarchy editor

Make it possible to open type hierarchy for different
class selected from Type Hierarchy editor.
Make it available under context menu or on double click
on class name (single click opens the class in cpp editor window
as before). Double click doesn't expand / collapse items anymore
(expanding available when pressing the visual arrow).
Make navigation to editor more up to date - e.g. when linked location
changed in meantime (source file was edited), it tries to find
linked symbol quickly again (we introduce a small delay, up to
100-200 ms, depending on source file).

Change-Id: Ifb4fd58e853589a17cd14be465b3a7695fa48193
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>
Reviewed-by: hjk <hjk@qt.io>

src/plugins/cpptools/cppelementevaluator.cpp

@@ -350,7 +350,7 @@ public:
 CppElementEvaluator::CppElementEvaluator(TextEditor::TextEditorWidget *editor) :
     m_editor(editor),
     m_modelManager(CppModelManager::instance()),
-    m_tc(editor->textCursor()),
+    m_tc(editor ? editor->textCursor() : QTextCursor()),
     m_lookupBaseClasses(false),
     m_lookupDerivedClasses(false)
 {}
@@ -364,6 +364,12 @@ void CppElementEvaluator::setLookupBaseClasses(const bool lookup)
 void CppElementEvaluator::setLookupDerivedClasses(const bool lookup)
 { m_lookupDerivedClasses = lookup; }
 
+void CppElementEvaluator::setExpression(const QString &expression, const QString &fileName)
+{
+    m_expression = expression;
+    m_fileName = fileName;
+}
+
 //  special case for bug QTCREATORBUG-4780
 static bool shouldOmitElement(const LookupItem &lookupItem, const Scope *scope)
 {
@@ -373,12 +379,17 @@ static bool shouldOmitElement(const LookupItem &lookupItem, const Scope *scope)
 
 void CppElementEvaluator::execute()
 {
-    execute(&CppElementEvaluator::syncExec);
+    execute(&CppElementEvaluator::sourceDataFromGui, &CppElementEvaluator::syncExec);
 }
 
 QFuture<QSharedPointer<CppElement>> CppElementEvaluator::asyncExecute()
 {
-    return execute(&CppElementEvaluator::asyncExec);
+    return execute(&CppElementEvaluator::sourceDataFromGui, &CppElementEvaluator::asyncExec);
+}
+
+QFuture<QSharedPointer<CppElement>> CppElementEvaluator::asyncExpressionExecute()
+{
+    return execute(&CppElementEvaluator::sourceDataFromExpression, &CppElementEvaluator::asyncExec);
 }
 
 static QFuture<QSharedPointer<CppElement>> createFinishedFuture()
@@ -389,18 +400,12 @@ static QFuture<QSharedPointer<CppElement>> createFinishedFuture()
     return futureInterface.future();
 }
 
-// @todo: Consider refactoring code from CppEditor::findLinkAt into here.
-QFuture<QSharedPointer<CppElement>> CppElementEvaluator::execute(ExecFunction execFuntion)
+bool CppElementEvaluator::sourceDataFromGui(const CPlusPlus::Snapshot &snapshot,
+                                            Document::Ptr &doc, Scope **scope, QString &expression)
 {
-    clear();
-
-    if (!m_modelManager)
-        return createFinishedFuture();
-
-    const Snapshot &snapshot = m_modelManager->snapshot();
-    Document::Ptr doc = snapshot.document(m_editor->textDocument()->filePath());
+    doc = snapshot.document(m_editor->textDocument()->filePath());
     if (!doc)
-        return createFinishedFuture();
+        return false;
 
     int line = 0;
     int column = 0;
@@ -410,14 +415,44 @@ QFuture<QSharedPointer<CppElement>> CppElementEvaluator::execute(ExecFunction ex
     checkDiagnosticMessage(pos);
 
     if (matchIncludeFile(doc, line) || matchMacroInUse(doc, pos))
-        return createFinishedFuture();
+        return false;
 
     CppTools::moveCursorToEndOfIdentifier(&m_tc);
+    ExpressionUnderCursor expressionUnderCursor(doc->languageFeatures());
+    expression = expressionUnderCursor(m_tc);
 
     // Fetch the expression's code
-    ExpressionUnderCursor expressionUnderCursor(doc->languageFeatures());
-    const QString &expression = expressionUnderCursor(m_tc);
-    Scope *scope = doc->scopeAt(line, column - 1);
+    *scope = doc->scopeAt(line, column - 1);
+    return true;
+}
+
+bool CppElementEvaluator::sourceDataFromExpression(const CPlusPlus::Snapshot &snapshot,
+                          Document::Ptr &doc, Scope **scope, QString &expression)
+{
+    doc = snapshot.document(m_fileName);
+    expression = m_expression;
+
+    // Fetch the expression's code
+    *scope = doc->globalNamespace();
+    return true;
+}
+
+// @todo: Consider refactoring code from CppEditor::findLinkAt into here.
+QFuture<QSharedPointer<CppElement>> CppElementEvaluator::execute(SourceFunction sourceFunction,
+                                                                 ExecFunction execFuntion)
+{
+    clear();
+
+    if (!m_modelManager)
+        return createFinishedFuture();
+
+    const Snapshot &snapshot = m_modelManager->snapshot();
+
+    Document::Ptr doc;
+    QString expression;
+    Scope *scope = nullptr;
+    if (!std::invoke(sourceFunction, this, snapshot, doc, &scope, expression))
+        return createFinishedFuture();
 
     TypeOfExpression typeOfExpression;
     typeOfExpression.init(doc, snapshot);
@@ -589,4 +624,28 @@ void CppElementEvaluator::clear()
     m_diagnosis.clear();
 }
 
+Utils::Link CppElementEvaluator::linkFromExpression(const QString &expression, const QString &fileName)
+{
+    const Snapshot &snapshot = CppModelManager::instance()->snapshot();
+    Document::Ptr doc = snapshot.document(fileName);
+    Scope *scope = doc->globalNamespace();
+
+    TypeOfExpression typeOfExpression;
+    typeOfExpression.init(doc, snapshot);
+    typeOfExpression.setExpandTemplates(true);
+    const QList<LookupItem> &lookupItems = typeOfExpression(expression.toUtf8(), scope);
+    if (lookupItems.isEmpty())
+        return Utils::Link();
+
+    for (const LookupItem &item : lookupItems) {
+        Symbol *symbol = item.declaration();
+        if (!symbol)
+            continue;
+        if (!symbol->isClass() && !symbol->isTemplate())
+            continue;
+        return symbol->toLink();
+    }
+    return Utils::Link();
+}
+
 } // namespace CppTools