Optional PC key blocks: function row, navigation, numeric keypad

- Template sections placed above or to the right of the typing keys;
  the user picks any mix in settings, typing keys included
- keysym keys send XKB keysyms on press, optionally repeating
- Geometry lays blocks side by side with one key unit; stretch keys are
  resolved at layout time so composed blocks line up
- Toggling a block resizes the window so keys keep their size

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/settings/Settings.cpp

@@ -1,10 +1,13 @@
 #include "Settings.h"
 
+#include "layout/Layout.h"
+
 #include <QSettings>
 
 namespace {
 constexpr auto AutoCapitalizeKey = "typing/autoCapitalize";
 constexpr auto DoubleSpacePeriodKey = "typing/doubleSpacePeriod";
+constexpr auto VisibleSectionsKey = "layout/visibleSections";
 }
 
 Settings::Settings(QObject *parent)
@@ -14,6 +17,23 @@ Settings::Settings(QObject *parent)
     const TypingOptions defaults;
     m_typing.autoCapitalize = store.value(AutoCapitalizeKey, defaults.autoCapitalize).toBool();
     m_typing.doubleSpacePeriod = store.value(DoubleSpacePeriodKey, defaults.doubleSpacePeriod).toBool();
+    m_visibleSections = store.value(VisibleSectionsKey, QStringList{MainSectionId}).toStringList();
+    if (m_visibleSections.isEmpty())
+        m_visibleSections = {MainSectionId};
+}
+
+void Settings::setSectionVisible(const QString &id, bool visible)
+{
+    QStringList sections = m_visibleSections;
+    if (visible && !sections.contains(id))
+        sections.append(id);
+    else if (!visible)
+        sections.removeAll(id);
+    if (sections == m_visibleSections || sections.isEmpty())
+        return;
+    m_visibleSections = sections;
+    QSettings().setValue(VisibleSectionsKey, m_visibleSections);
+    Q_EMIT visibleSectionsChanged();
 }
 
 void Settings::setAutoCapitalize(bool enabled)

src/settings/Settings.h

@@ -3,6 +3,7 @@
 #include "input/TypingOptions.h"
 
 #include <QObject>
+#include <QStringList>
 #include <QtQml/qqmlregistration.h>
 
 // User preferences, persisted with QSettings (~/.config/sloposk/sloposk.conf)
@@ -14,6 +15,8 @@ class Settings : public QObject
     QML_UNCREATABLE("Created in C++")
     Q_PROPERTY(bool autoCapitalize READ autoCapitalize WRITE setAutoCapitalize NOTIFY typingOptionsChanged)
     Q_PROPERTY(bool doubleSpacePeriod READ doubleSpacePeriod WRITE setDoubleSpacePeriod NOTIFY typingOptionsChanged)
+    // Which key blocks are shown: "main" (the typing keys) and template section ids.
+    Q_PROPERTY(QStringList visibleSections READ visibleSections NOTIFY visibleSectionsChanged)
 
 public:
     explicit Settings(QObject *parent = nullptr);
@@ -25,11 +28,17 @@ public:
     bool doubleSpacePeriod() const { return m_typing.doubleSpacePeriod; }
     void setDoubleSpacePeriod(bool enabled);
 
+    QStringList visibleSections() const { return m_visibleSections; }
+    // Hiding the last visible section is refused: something must stay on screen.
+    Q_INVOKABLE void setSectionVisible(const QString &id, bool visible);
+
 Q_SIGNALS:
     void typingOptionsChanged();
+    void visibleSectionsChanged();
 
 private:
     void setTypingOptions(const TypingOptions &options);
 
     TypingOptions m_typing;
+    QStringList m_visibleSections;
 };