Full keyboard mode, Ctrl/Alt/Super, dead keys, shift levels

- Full (iPad Pro) mode: every typing key from the keymap, number row,
  tab, caps lock, ctrl/super/alt; shifted symbol shown above and flickable
- Dead keys compose with the locale's XKB compose table
- Ctrl/Alt/Super stick like shift and turn keys into shortcuts; a tapped
  or held shift joins shortcuts and non-text keys, auto-shift and caps
  lock don't
- Auto-capitalization and caps lock only capitalize letters; the user's
  shift picks the keymap's shifted level
- Mode switch in settings keeps key size by resizing the window

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

src/layout/LayoutModel.cpp

@@ -12,12 +12,15 @@ QString keyTypeName(KeyType type)
     case KeyType::Backspace: return QStringLiteral("backspace");
     case KeyType::Enter: return QStringLiteral("enter");
     case KeyType::Shift: return QStringLiteral("shift");
+    case KeyType::CapsLock: return QStringLiteral("capslock");
+    case KeyType::Modifier: return QStringLiteral("modifier");
     case KeyType::LayerSwitch: return QStringLiteral("layer");
     case KeyType::Globe: return QStringLiteral("globe");
     case KeyType::Dismiss: return QStringLiteral("dismiss");
     case KeyType::Spacer: return QStringLiteral("spacer");
     case KeyType::Keysym: return QStringLiteral("keysym");
-    case KeyType::Letters: break; // expanded before it reaches the model
+    case KeyType::Letters:
+    case KeyType::Keys: break; // expanded before it reaches the model
     }
     return {};
 }
@@ -44,8 +47,10 @@ QVariant LayoutModel::data(const QModelIndex &index, int role) const
     const KeyDef &key = m_keys.at(index.row());
     const QRectF rect = m_rects.value(index.row());
     switch (role) {
-    case LabelRole: return key.text(m_uppercase);
-    case FlickLabelRole: return key.flick;
+    case LabelRole: return key.text(m_shiftLevel);
+    // A shifted key already shows its shifted symbol (! on 1): don't repeat it.
+    case FlickLabelRole: return m_shiftLevel == ShiftLevel::Shifted && key.flick == key.shifted ? QString() : key.flick;
+    case ModifierRole: return key.modifier;
     case KeyTypeRole: return keyTypeName(key.type);
     case KeyXRole: return rect.x();
     case KeyYRole: return rect.y();
@@ -69,6 +74,7 @@ QHash<int, QByteArray> LayoutModel::roleNames() const
         {KeyHeightRole, "keyHeight"},
         {PressedRole, "pressed"},
         {FlickProgressRole, "flickProgress"},
+        {ModifierRole, "modifier"},
     };
 }
 
@@ -111,6 +117,11 @@ qreal LayoutModel::totalUnits() const
     return ::totalUnits(m_blocks);
 }
 
+qsizetype LayoutModel::totalRows() const
+{
+    return ::totalRows(m_blocks);
+}
+
 void LayoutModel::setSize(QSizeF size)
 {
     if (size == m_size)
@@ -121,13 +132,13 @@ void LayoutModel::setSize(QSizeF size)
         Q_EMIT dataChanged(index(0), index(rowCount() - 1), {KeyXRole, KeyYRole, KeyWidthRole, KeyHeightRole});
 }
 
-void LayoutModel::setUppercase(bool uppercase)
+void LayoutModel::setShiftLevel(ShiftLevel level)
 {
-    if (uppercase == m_uppercase)
+    if (level == m_shiftLevel)
         return;
-    m_uppercase = uppercase;
+    m_shiftLevel = level;
     if (!m_keys.isEmpty())
-        Q_EMIT dataChanged(index(0), index(rowCount() - 1), {LabelRole});
+        Q_EMIT dataChanged(index(0), index(rowCount() - 1), {LabelRole, FlickLabelRole});
 }
 
 void LayoutModel::setPressed(int row, bool pressed)