TextEditor: Use invokeMethod instead of singleShot timer with 0 delay

Use QCoreApplication::instance() as a context object for the
IAssistProposal deleter.

Change-Id: Idf8cd1955dca146a500da1ea036298455c8a5da1
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/texteditor/codeassist/codeassistant.cpp

@@ -254,7 +254,9 @@ void CodeAssistantPrivate::requestProposal(AssistReason reason,
     case IAssistProvider::Asynchronous: {
         processor->setAsyncCompletionAvailableHandler([this, reason, processor](IAssistProposal *newProposal) {
             // do not delete this processor directly since this function is called from within the processor
-            QTimer::singleShot(0, [processor]() { delete processor; });
+            QMetaObject::invokeMethod(QCoreApplication::instance(), [processor]() {
+                delete processor;
+            }, Qt::QueuedConnection);
             if (processor != m_asyncProcessor)
                 return;
             invalidateCurrentRequestData();

src/plugins/texteditor/syntaxhighlighter.cpp

@@ -34,7 +34,6 @@
 
 #include <QTextDocument>
 #include <QPointer>
-#include <qtimer.h>
 
 #include <cmath>
 
@@ -310,7 +309,8 @@ void SyntaxHighlighter::setDocument(QTextDocument *doc)
         if (!d->noAutomaticHighlighting) {
             connect(d->doc, &QTextDocument::contentsChange, this, &SyntaxHighlighter::reformatBlocks);
             d->rehighlightPending = true;
-            QTimer::singleShot(0, this, &SyntaxHighlighter::delayedRehighlight);
+            QMetaObject::invokeMethod(this, &SyntaxHighlighter::delayedRehighlight,
+                                      Qt::QueuedConnection);
         }
         d->foldValidator.setup(qobject_cast<TextDocumentLayout *>(doc->documentLayout()));
     }

src/plugins/texteditor/textdocument.cpp

@@ -51,7 +51,6 @@
 #include <QScrollBar>
 #include <QStringList>
 #include <QTextCodec>
-#include <QTimer>
 
 #include <coreplugin/coreconstants.h>
 #include <coreplugin/icore.h>
@@ -1014,7 +1013,8 @@ void TextDocument::removeMarkFromMarksCache(TextMark *mark)
     auto scheduleLayoutUpdate = [documentLayout](){
         // make sure all destructors that may directly or indirectly call this function are
         // completed before updating.
-        QTimer::singleShot(0, documentLayout, &QPlainTextDocumentLayout::requestUpdate);
+        QMetaObject::invokeMethod(documentLayout, &QPlainTextDocumentLayout::requestUpdate,
+                                  Qt::QueuedConnection);
     };
 
     if (d->m_marksCache.isEmpty()) {

src/plugins/texteditor/texteditor.cpp

@@ -177,12 +177,12 @@ public:
         connect(m_editor, &QPlainTextEdit::cursorPositionChanged, this, &LineColumnLabel::update);
         connect(this, &FixedSizeClickLabel::clicked, ActionManager::instance(), [this] {
             emit m_editor->activateEditor(EditorManager::IgnoreNavigationHistory);
-            QTimer::singleShot(0, ActionManager::instance(), [] {
+            QMetaObject::invokeMethod(ActionManager::instance(), [] {
                 if (Command *cmd = ActionManager::command(Core::Constants::GOTO)) {
                     if (QAction *act = cmd->action())
                         act->trigger();
                 }
-            });
+            }, Qt::QueuedConnection);
         });
     }
 
@@ -5421,7 +5421,7 @@ void TextEditorWidgetPrivate::updateHighlights()
     }
 
     if (m_highlightAutoComplete && !m_autoCompleteHighlightPos.isEmpty()) {
-        QTimer::singleShot(0, this, [this](){
+        QMetaObject::invokeMethod(this, [this]() {
             const QTextCursor &cursor = q->textCursor();
             auto popAutoCompletion = [&]() {
                 return !m_autoCompleteHighlightPos.isEmpty()
@@ -5432,7 +5432,7 @@ void TextEditorWidgetPrivate::updateHighlights()
                     m_autoCompleteHighlightPos.pop_back();
                 updateAutoCompleteHighlight();
             }
-        });
+        }, Qt::QueuedConnection);
     }
 
     updateCurrentLineHighlight();
@@ -6287,7 +6287,7 @@ void TextEditorWidgetPrivate::requestUpdateLink(QMouseEvent *e)
 
     if (onText) {
         m_pendingLinkUpdate = cursor;
-        QTimer::singleShot(0, this, &TextEditorWidgetPrivate::updateLink);
+        QMetaObject::invokeMethod(this, &TextEditorWidgetPrivate::updateLink, Qt::QueuedConnection);
         return;
     }
 
@@ -6444,7 +6444,8 @@ void TextEditorWidgetPrivate::scheduleUpdateHighlightScrollBar()
         return;
 
     m_scrollBarUpdateScheduled = true;
-    QTimer::singleShot(0, this, &TextEditorWidgetPrivate::updateHighlightScrollBarNow);
+    QMetaObject::invokeMethod(this, &TextEditorWidgetPrivate::updateHighlightScrollBarNow,
+                              Qt::QueuedConnection);
 }
 
 Highlight::Priority textMarkPrioToScrollBarPrio(const TextMark::Priority &prio)