From dbf90acfa110122cb4e993babb0f75a411355795 Mon Sep 17 00:00:00 2001
From: Lars Op den Kamp <lars@opdenkamp.eu>
Date: Sun, 7 Oct 2012 12:07:47 +0200
Subject: [PATCH] prevent double taps by not sending the same key press twice
 within 200ms

---
 include/cectypes.h    |  5 +++++
 src/lib/CECClient.cpp | 20 ++++++++++++++++++--
 src/lib/CECClient.h   |  2 ++
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/include/cectypes.h b/include/cectypes.h
index d05a392..c80354e 100644
--- a/include/cectypes.h
+++ b/include/cectypes.h
@@ -79,6 +79,11 @@ namespace CEC {
  */
 #define CEC_BUTTON_TIMEOUT           500
 
+/*!
+ * don't send the same key twice within this timeout in milliseconds
+ */
+#define CEC_DOUBLE_TAP_TIMEOUT_MS    200
+
 /*!
  * don't query the power state for the same device within this timeout in milliseconds
  */
diff --git a/src/lib/CECClient.cpp b/src/lib/CECClient.cpp
index 3ae420e..cafcd70 100644
--- a/src/lib/CECClient.cpp
+++ b/src/lib/CECClient.cpp
@@ -56,8 +56,11 @@ CCECClient::CCECClient(CCECProcessor *processor, const libcec_configuration &con
     m_bRegistered(false),
     m_iCurrentButton(CEC_USER_CONTROL_CODE_UNKNOWN),
     m_buttontime(0),
-    m_iPreventForwardingPowerOffCommand(0)
+    m_iPreventForwardingPowerOffCommand(0),
+    m_iLastKeypressTime(0)
 {
+  m_lastKeypress.keycode = CEC_USER_CONTROL_CODE_UNKNOWN;
+  m_lastKeypress.duration = 0;
   m_configuration.Clear();
   // set the initial configuration
   SetConfiguration(configuration);
@@ -1424,7 +1427,20 @@ void CCECClient::CallbackAddKey(const cec_keypress &key)
 {
   CLockObject lock(m_cbMutex);
   if (m_configuration.callbacks && m_configuration.callbacks->CBCecKeyPress)
-    m_configuration.callbacks->CBCecKeyPress(m_configuration.callbackParam, key);
+  {
+    // prevent double taps
+    int64_t now = GetTimeMs();
+    if (m_lastKeypress.keycode != key.keycode ||
+        key.duration > 0 ||
+        now - m_iLastKeypressTime >= CEC_DOUBLE_TAP_TIMEOUT_MS)
+    {
+      // no double tap
+      if (key.duration == 0)
+        m_iLastKeypressTime = now;
+      m_lastKeypress = key;
+      m_configuration.callbacks->CBCecKeyPress(m_configuration.callbackParam, key);
+    }
+  }
 }
 
 void CCECClient::CallbackAddLog(const cec_log_message &message)
diff --git a/src/lib/CECClient.h b/src/lib/CECClient.h
index e757464..11a6504 100644
--- a/src/lib/CECClient.h
+++ b/src/lib/CECClient.h
@@ -307,5 +307,7 @@ namespace CEC
     cec_user_control_code m_iCurrentButton;                    /**< the control code of the button that's currently held down (if any) */
     int64_t               m_buttontime;                        /**< the timestamp when the button was pressed (in seconds since epoch), or 0 if none was pressed. */
     int64_t               m_iPreventForwardingPowerOffCommand; /**< prevent forwarding standby commands until this time */
+    int64_t               m_iLastKeypressTime;                 /**< last time a key press was sent to the client */
+    cec_keypress          m_lastKeypress;                      /**< the last key press that was sent to the client */
   };
 }
-- 
2.34.1