Editor: paint location marker over everything else

The location marker is updated very regularly and especially while
stepping moves one line at a time. Resizing this marker when it enters a
line that already contains a marker is visually distracting. To prevent
this paint the marker over all other markers in that line.

Change-Id: I63ad72384e77eeae4dc6d2e2c2ac77c88da92c56
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/debugger/debuggerengine.cpp

@@ -156,6 +156,7 @@ LocationMark::LocationMark(DebuggerEngine *engine, const FilePath &file, int lin
     : TextMark(file, line, Constants::TEXT_MARK_CATEGORY_LOCATION), m_engine(engine)
 {
     setPriority(TextMark::HighPriority);
+    setIsLocationMarker(true);
     updateIcon();
 }
 

src/plugins/texteditor/textdocument.cpp

@@ -983,6 +983,10 @@ bool TextDocument::addMark(TextMark *mark)
         // Update document layout
         bool fullUpdate = !documentLayout->hasMarks;
         documentLayout->hasMarks = true;
+        if (!documentLayout->hasLocationMarker && mark->isLocationMarker()) {
+            documentLayout->hasLocationMarker = true;
+            fullUpdate = true;
+        }
         if (fullUpdate)
             documentLayout->scheduleUpdate();
         else
@@ -1018,6 +1022,11 @@ void TextDocument::removeMarkFromMarksCache(TextMark *mark)
                                   Qt::QueuedConnection);
     };
 
+    if (mark->isLocationMarker()) {
+        documentLayout->hasLocationMarker = false;
+        scheduleLayoutUpdate();
+    }
+
     if (d->m_marksCache.isEmpty()) {
         documentLayout->hasMarks = false;
         scheduleLayoutUpdate();

src/plugins/texteditor/textdocumentlayout.h

@@ -203,6 +203,7 @@ public:
 
     int lastSaveRevision = 0;
     bool hasMarks = false;
+    bool hasLocationMarker = false;
     int m_requiredWidth = 0;
 
     void setRequiredWidth(int width);

src/plugins/texteditor/texteditor.cpp

@@ -4930,35 +4930,46 @@ void TextEditorWidgetPrivate::paintTextMarks(QPainter &painter, const ExtraAreaP
     QList<QIcon> icons;
     auto end = marks.crend();
     int marksWithIconCount = 0;
+    QIcon overrideIcon;
     for (auto it = marks.crbegin(); it != end; ++it) {
         if ((*it)->isVisible()) {
             const QIcon icon = (*it)->icon();
             if (!icon.isNull()) {
-                if (icons.size() < 3
+                if ((*it)->isLocationMarker()) {
-                    && !Utils::contains(icons, Utils::equal(&QIcon::cacheKey, icon.cacheKey()))) {
+                    overrideIcon = icon;
-                    icons << icon;
+                } else {
+                    if (icons.size() < 3
+                            && !Utils::contains(icons, Utils::equal(&QIcon::cacheKey, icon.cacheKey()))) {
+                        icons << icon;
+                    }
+                    ++marksWithIconCount;
                 }
-                ++marksWithIconCount;
             }
         }
     }
 
-    if (icons.isEmpty())
-        return;
-
-    painter.save();
-    Utils::ExecuteOnDestruction painterRestore([&]() { painter.restore(); });
 
     int size = data.lineSpacing - 1;
     int xoffset = 0;
     int yoffset = blockBoundingRect.top();
 
+    painter.save();
+    Utils::ExecuteOnDestruction eod([&painter, size, yoffset, xoffset, overrideIcon]() {
+        if (!overrideIcon.isNull()) {
+            const QRect r(xoffset, yoffset, size, size);
+            overrideIcon.paint(&painter, r, Qt::AlignCenter);
+        }
+        painter.restore();
+    });
+
+    if (icons.isEmpty())
+        return;
+
     if (icons.size() == 1) {
         const QRect r(xoffset, yoffset, size, size);
         icons.first().paint(&painter, r, Qt::AlignCenter);
         return;
     }
-
     size = size / 2;
     for (const QIcon &icon : qAsConst(icons)) {
         const QRect r(xoffset, yoffset, size, size);

src/plugins/texteditor/textmark.cpp

@@ -409,6 +409,16 @@ void TextMark::setSettingsPage(Id settingsPage)
     m_settingsPage = settingsPage;
 }
 
+bool TextMark::isLocationMarker() const
+{
+    return m_isLocationMarker;
+}
+
+void TextMark::setIsLocationMarker(bool newIsLocationMarker)
+{
+    m_isLocationMarker = newIsLocationMarker;
+}
+
 TextMarkRegistry::TextMarkRegistry(QObject *parent)
     : QObject(parent)
 {

src/plugins/texteditor/textmark.h

@@ -111,6 +111,9 @@ public:
     void setActions(const QVector<QAction *> &actions); // Takes ownership
     void setActionsProvider(const std::function<QList<QAction *>()> &actionsProvider); // Takes ownership
 
+    bool isLocationMarker() const;;
+    void setIsLocationMarker(bool newIsLocationMarker);
+
 protected:
     void setSettingsPage(Utils::Id settingsPage);
 
@@ -121,6 +124,7 @@ private:
     Utils::FilePath m_fileName;
     int m_lineNumber = 0;
     Priority m_priority = LowPriority;
+    bool m_isLocationMarker = false;
     QIcon m_icon;
     std::function<QIcon()> m_iconProvider;
     std::optional<Utils::Theme::Color> m_color;