5 files changed, 98 insertions, 0 deletions
diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index 3a82f5b80..9d5a90762 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -4,10 +4,12 @@ configure_file("${CMAKE_CURRENT_SOURCE_DIR}/scm_rev.cpp.in" "${CMAKE_CURRENT_SOU
 set(SRCS
             break_points.cpp
             console_listener.cpp
+            emu_window.cpp
             extended_trace.cpp
             file_search.cpp
             file_util.cpp
             hash.cpp
+            key_map.cpp
             log_manager.cpp
             math_util.cpp
             mem_arena.cpp
@@ -39,6 +41,7 @@ set(HEADERS
             file_search.h
             file_util.h
             hash.h
+            key_map.h
             linear_disk_cache.h
             log.h
             log_manager.h
diff --git a/src/common/emu_window.cpp b/src/common/emu_window.cpp
new file mode 100644
index 000000000..7a2c50ac8
--- /dev/null
+++ b/src/common/emu_window.cpp
@@ -0,0 +1,17 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.
+
+#include "emu_window.h"
+
+void EmuWindow::KeyPressed(KeyMap::HostDeviceKey key) {
+    HID_User::PadState mapped_key = KeyMap::GetPadKey(key);
+
+    HID_User::PadButtonPress(mapped_key);
+}
+
+void EmuWindow::KeyReleased(KeyMap::HostDeviceKey key) {
+    HID_User::PadState mapped_key = KeyMap::GetPadKey(key);
+
+    HID_User::PadButtonRelease(mapped_key);
+}
diff --git a/src/common/emu_window.h b/src/common/emu_window.h
index 5e2c33d7a..23f178fdf 100644
--- a/src/common/emu_window.h
+++ b/src/common/emu_window.h
@@ -7,6 +7,8 @@
 #include "common/common.h"
 #include "common/scm_rev.h"
 
+#include "common/key_map.h"
+
 // Abstraction class used to provide an interface between emulation code and the frontend (e.g. SDL, 
 //  QGLWidget, GLFW, etc...)
 class EmuWindow
@@ -32,6 +34,12 @@ public:
     /// Releases (dunno if this is the "right" word) the GLFW context from the caller thread
     virtual void DoneCurrent() = 0;
 
+    /// Signals a key press action to the HID module
+    static void KeyPressed(KeyMap::HostDeviceKey key);
+
+    /// Signals a key release action to the HID module
+    static void KeyReleased(KeyMap::HostDeviceKey key);
+
     Config GetConfig() const { 
         return m_config;
     }
diff --git a/src/common/key_map.cpp b/src/common/key_map.cpp
new file mode 100644
index 000000000..309caab98
--- /dev/null
+++ b/src/common/key_map.cpp
@@ -0,0 +1,25 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.
+
+#include "key_map.h"
+#include <map>
+
+namespace KeyMap {
+
+static std::map<HostDeviceKey, HID_User::PadState> key_map;
+static int next_device_id = 0;
+
+int NewDeviceId() {
+    return next_device_id++;
+}
+
+void SetKeyMapping(HostDeviceKey key, HID_User::PadState padState) {
+    key_map[key].hex = padState.hex;
+}
+
+HID_User::PadState GetPadKey(HostDeviceKey key) {
+    return key_map[key];
+}
+
+}
diff --git a/src/common/key_map.h b/src/common/key_map.h
new file mode 100644
index 000000000..b5acfbab0
--- /dev/null
+++ b/src/common/key_map.h
@@ -0,0 +1,45 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/hle/service/hid.h"
+
+namespace KeyMap {
+
+/**
+ * Represents a key for a specific host device.
+ */
+struct HostDeviceKey {
+    int key_code;
+    int device_id; ///< Uniquely identifies a host device
+
+    bool operator < (const HostDeviceKey &other) const {
+        if (device_id == other.device_id) {
+            return key_code < other.key_code;
+        }
+        return device_id < other.device_id;
+    }
+
+    bool operator == (const HostDeviceKey &other) const {
+        return device_id == other.device_id && key_code == other.key_code;
+    }
+};
+
+/**
+ * Generates a new device id, which uniquely identifies a host device within KeyMap.
+ */
+int NewDeviceId();
+
+/**
+ * Maps a device-specific key to a PadState.
+ */
+void SetKeyMapping(HostDeviceKey key, HID_User::PadState padState);
+
+/**
+ * Gets the PadState that's mapped to the provided device-specific key.
+ */
+HID_User::PadState GetPadKey(HostDeviceKey key);
+
+}