use same font metrics for qml and c++ code

app/dock/dockconfigview.cpp

@@ -128,8 +128,6 @@ void DockConfigView::init()
 
     QByteArray tempFilePath = "lattedockconfigurationui";
 
-    m_largeSpacing = QFontMetrics(QGuiApplication::font()).boundingRect(QStringLiteral("M")).height();
-
     updateEnabledBorders();
 
     auto source = QUrl::fromLocalFile(m_dockView->containment()->corona()->kPackage().filePath(tempFilePath));
@@ -202,7 +200,7 @@ void DockConfigView::syncGeometry()
     const auto location = m_dockView->containment()->location();
     const auto sGeometry = screen()->geometry();
 
-    int clearThickness = m_dockView->normalThickness() + m_largeSpacing;
+    int clearThickness = m_dockView->normalThickness() + m_dockView->fontPixelSize();
 
     QPoint position{0, 0};
 

app/dock/dockconfigview.h

@@ -113,8 +113,6 @@ private:
     bool m_inReverse{false};    //! it is used by the borders
     bool m_showInlineProperties{false};
 
-    int m_largeSpacing;
-
     QPointer<DockView> m_dockView;
     QPointer<DockSecConfigView> m_secConfigView;
     QTimer m_screenSyncTimer;

app/dock/docksecconfigview.cpp

@@ -118,8 +118,6 @@ void DockSecConfigView::init()
 
     QByteArray tempFilePath = "lattedocksecondaryconfigurationui";
 
-    m_largeSpacing = QFontMetrics(QGuiApplication::font()).boundingRect(QStringLiteral("M")).height();
-
     updateEnabledBorders();
 
     auto source = QUrl::fromLocalFile(m_dockView->containment()->corona()->kPackage().filePath(tempFilePath));
@@ -149,9 +147,9 @@ void DockSecConfigView::syncGeometry()
     const auto location = m_dockView->containment()->location();
     const auto sGeometry = screen()->geometry();
 
-    int clearThickness = m_dockView->normalThickness() + m_largeSpacing;
+    int clearThickness = m_dockView->normalThickness() + m_dockView->fontPixelSize();
 
-    int secondaryConfigSpacing = 2 * m_largeSpacing;
+    int secondaryConfigSpacing = 2 * m_dockView->fontPixelSize();
 
     QPoint position{0, 0};
 

app/dock/docksecconfigview.h

@@ -82,8 +82,6 @@ private slots:
 private:
     void setupWaylandIntegration();
 
-    int m_largeSpacing;
-
     QPointer<DockView> m_dockView;
     QPointer<QWindow> m_parent;
     QTimer m_screenSyncTimer;

app/dock/dockview.cpp

@@ -1324,6 +1324,22 @@ void DockView::setShadow(int shadow)
     emit shadowChanged();
 }
 
+int DockView::fontPixelSize() const
+{
+    return m_fontPixelSize;
+}
+
+void DockView::setFontPixelSize(int size)
+{
+    if (m_fontPixelSize == size) {
+        return;
+    }
+
+    m_fontPixelSize = size;
+
+    emit fontPixelSizeChanged();
+}
+
 void DockView::applyActivitiesToWindows()
 {
     if (m_visibility) {

app/dock/dockview.h

@@ -74,6 +74,7 @@ class DockView : public PlasmaQuick::ContainmentView {
     Q_PROPERTY(int alignment READ alignment WRITE setAlignment NOTIFY alignmentChanged)
     Q_PROPERTY(int docksCount READ docksCount NOTIFY docksCountChanged)
     Q_PROPERTY(int dockTransparency READ dockTransparency WRITE setDockTransparency NOTIFY dockTransparencyChanged)
+    Q_PROPERTY(int fontPixelSize READ fontPixelSize WRITE setFontPixelSize NOTIFY fontPixelSizeChanged)
     Q_PROPERTY(int totalDocksCount READ totalDocksCount NOTIFY totalDocksCountChanged)
     Q_PROPERTY(int x READ x NOTIFY xChanged)
     Q_PROPERTY(int y READ y NOTIFY yChanged)
@@ -147,6 +148,9 @@ public:
     int dockTransparency() const;
     void setDockTransparency(int transparency);
 
+    int fontPixelSize() const;
+    void setFontPixelSize(int size);
+
     int maxThickness() const;
     void setMaxThickness(int thickness);
 
@@ -266,6 +270,7 @@ signals:
     void drawEffectsChanged();
     void effectsAreaChanged();
     void enabledBordersChanged();
+    void fontPixelSizeChanged();
     void widthChanged();
     void heightChanged();
     void inEditModeChanged();
@@ -321,6 +326,7 @@ private:
     bool m_inEditMode{false};
     bool m_onPrimary{true};
     int m_dockTransparency{100};
+    int m_fontPixelSize{-1};
     int m_maxThickness{24};
     int m_normalThickness{24};
     int m_offset{0};

containment/package/contents/ui/VisibilityManager.qml

@@ -117,6 +117,13 @@ Item{
                && (!root.inStartup || inForceHiding || inTempHiding)
     }
 
+    Binding{
+        target: dock
+        property: "fontPixelSize"
+        when: theme
+        value: theme.defaultFont.pixelSize
+    }
+
     Binding{
         target: dock
         property:"inEditMode"