feat: add KeyMap with defaults and INI overrides

Maps key sequences to action name strings, with hardcoded vim-style
defaults and QSettings-based [keys] overrides. Unknown actions and
unparseable sequences are collected as warnings rather than treated
as fatal, so a typo in the config cannot silently misbind or crash.

Note: QKeySequence::fromString() on Qt 6.11 does not return an empty
sequence for unparseable input (e.g. "NotAKey++") -- it returns a
non-empty sequence whose toString() is empty. Detection uses that
instead of isEmpty().

1 files changed, 32 insertions, 0 deletions

diff --git a/src/keymap.h b/src/keymap.h
new file mode 100644
index 0000000..3f0f85c
--- /dev/null
+++ b/src/keymap.h
@@ -0,0 +1,32 @@
+#pragma once
+
+#include <QHash>
+#include <QKeySequence>
+#include <QStringList>
+
+class QSettings;
+
+/// Maps key sequences to action names. Action names are plain strings so this
+/// class has no dependency on the widgets that implement the actions.
+class KeyMap
+{
+public:
+    /// Every action name the application understands. loadOverrides() rejects
+    /// anything not in this set, so a typo in the config cannot bind silently.
+    static QStringList knownActions();
+
+    void loadDefaults();
+
+    /// Reads the [keys] group. Invalid sequences and unknown action names are
+    /// collected into warnings() rather than throwing or aborting.
+    void loadOverrides(QSettings &settings);
+
+    /// Empty string when nothing is bound.
+    QString actionFor(const QKeySequence &sequence) const;
+
+    QStringList warnings() const { return m_warnings; }
+
+private:
+    QHash<QKeySequence, QString> m_bindings;
+    QStringList m_warnings;
+};