Ozone keyboard layout

ui/events/ozone/layout/keyboard_layout_engine.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_OZONE_PUBLIC_KEYBOARD_LAYOUT_ENGINE_H_
+#define UI_OZONE_PUBLIC_KEYBOARD_LAYOUT_ENGINE_H_
+
+#include <string>
+
+#include "base/strings/string16.h"
+#include "ui/events/keycodes/keyboard_codes.h"
+#include "ui/events/ozone/layout/events_ozone_layout_export.h"
+
+namespace ui {
+
+enum class DomCode;
+enum class DomKey;
+
+// XXX TODO(kpschoedel): document me
+class EVENTS_OZONE_LAYOUT_EXPORT KeyboardLayoutEngine {
+ public:
+  KeyboardLayoutEngine() {}
+  virtual ~KeyboardLayoutEngine() {}
+
+  // Returns true if it is possible to change the current layout.
+  virtual bool CanSetCurrentLayout() const = 0;
+
+  // Sets the current layout; returns true on success.
+  virtual bool SetCurrentLayoutByName(const std::string& layout_name) = 0;
+
+  // Returns true if the current layout makes use of the ISO Level 5 Shift key.
+  virtual bool UsesISOLevel5Shift() const = 0;
+
+  // Returns true if the current layout makes use of the AltGr
+  // (ISO Level 3 Shift) key.
+  virtual bool UsesAltGr() const = 0;
+
+  // Provides the interpretation of a physical key.
+  //
+  // The caller must supply valid addresses for all the output parameters;
+  // the function must not use their initial values.
+  //
+  // If the function can determine an interpretation of the (dom_code, flags)
+  // values, it must set *dom_key and must set *character, may optionally
+  // set *key_code, and returns true. A layout function that does not directly
+  // know the correct KeyboardCode should not touch *key_code.
+  //
+  // If the function can determine that the (dom_code, flags) values have NO
+  // interpretation in the current layout (e.g. the key is unbound), it must
+  // set *dom_key to UNIDENTIFIED and *character to 0, should set *key_code
+  // to VKEY_UNKNOWN if and only if it would normally set *key_code, and
+  // returns true.
+  //
+  // Otherwise -- if it cannot determine the interpretation, and cannot
+  // determine that there is none -- it must not set any of the output
+  // parameters, and returns false.
+  virtual bool Lookup(DomCode dom_code,
+                      int flags,
+                      DomKey* dom_key,
+                      base::char16* character,
+                      KeyboardCode* key_code) const = 0;
+};
+
+}  // namespace ui
+
+#endif  // UI_OZONE_PUBLIC_KEYBOARD_LAYOUT_ENGINE_H_