From 17dafd8c50d828a3334586dd558a12270ba6bdc0 Mon Sep 17 00:00:00 2001
From: Daniele Pallastrelli <5451767+daniele77@users.noreply.github.com>
Date: Fri, 26 Apr 2024 20:07:47 +0200
Subject: [PATCH] close #239 (enable keyboard handling in command handlers on
 linux)

---
 CHANGELOG.md                       |  1 +
 include/cli/detail/inputdevice.h   |  2 ++
 include/cli/detail/inputhandler.h  |  8 ++++++--
 include/cli/detail/linuxkeyboard.h | 26 ++++++++++++++++++++++++--
 4 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8418fe0..566faa3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
  - Parent menus does not chain (issue [#234](https://github.com/daniele77/cli/issues/234))
  - Parent menu shortcut (issue [#233](https://github.com/daniele77/cli/issues/233))
  - Integer overflow warning detected by clang++ (issue [#236](https://github.com/daniele77/cli/issues/236))
+ - Enable Keyboard Handling in Command Handlers on Linux Platform (issue [#239](https://github.com/daniele77/cli/issues/239))
 
 ## [2.1.0] - 2023-06-29
 
diff --git a/include/cli/detail/inputdevice.h b/include/cli/detail/inputdevice.h
index 5655ed8..bb536e3 100644
--- a/include/cli/detail/inputdevice.h
+++ b/include/cli/detail/inputdevice.h
@@ -48,6 +48,8 @@ class InputDevice
 
     explicit InputDevice(Scheduler& _scheduler) : scheduler(_scheduler) {}
     virtual ~InputDevice() = default;
+    virtual void ActivateInput() {}
+    virtual void DeactivateInput() {}
 
     template <typename H>
     void Register(H&& h) { handler = std::forward<H>(h); }
diff --git a/include/cli/detail/inputhandler.h b/include/cli/detail/inputhandler.h
index ac9170e..5f0310e 100644
--- a/include/cli/detail/inputhandler.h
+++ b/include/cli/detail/inputhandler.h
@@ -45,9 +45,10 @@ namespace detail
 class InputHandler
 {
 public:
-    InputHandler(CliSession& _session, InputDevice& kb) :
+    InputHandler(CliSession& _session, InputDevice& _kb) :
         session(_session),
-        terminal(session.OutStream())
+        terminal(session.OutStream()),
+        kb(_kb)
     {
         kb.Register( [this](auto key){ this->Keypressed(key); } );
     }
@@ -75,8 +76,10 @@ class InputHandler
             }
             case Symbol::command:
             {
+                kb.DeactivateInput();
                 session.Feed(s.second);
                 session.Prompt();
+                kb.ActivateInput();
                 break;
             }
             case Symbol::down:
@@ -124,6 +127,7 @@ class InputHandler
 
     CliSession& session;
     Terminal terminal;
+    InputDevice& kb;
 };
 
 } // namespace detail
diff --git a/include/cli/detail/linuxkeyboard.h b/include/cli/detail/linuxkeyboard.h
index 72ec901..d58e396 100644
--- a/include/cli/detail/linuxkeyboard.h
+++ b/include/cli/detail/linuxkeyboard.h
@@ -32,13 +32,14 @@
 
 #include <thread>
 #include <memory>
+#include <stdexcept>
 
 #include <cstdio>
 #include <termios.h>
 #include <unistd.h>
 #include <sys/select.h>
 #include <cassert>
-
+#include <condition_variable>
 #include "inputdevice.h"
 
 
@@ -106,9 +107,10 @@ class LinuxKeyboard : public InputDevice
 public:
     explicit LinuxKeyboard(Scheduler& _scheduler) :
         InputDevice(_scheduler),
+        enabled(false),
         servant( [this]() noexcept { Read(); } )
     {
-        ToManualMode();
+        ActivateInput();
     }
     ~LinuxKeyboard() override
     {
@@ -116,6 +118,19 @@ class LinuxKeyboard : public InputDevice
         is.Stop();
         servant.join();
     }
+    void ActivateInput() override
+    {
+        ToManualMode();
+        std::lock_guard<std::mutex> lock(mtx);
+        enabled = true;
+        cv.notify_one();
+    }
+    void DeactivateInput() override
+    {
+        ToStandardMode();
+        std::lock_guard<std::mutex> lock(mtx);
+        enabled = false;
+    }
 
 private:
 
@@ -125,6 +140,10 @@ class LinuxKeyboard : public InputDevice
         {
             while (true)
             {
+                {
+                    std::unique_lock<std::mutex> lock(mtx);
+                    cv.wait(lock, [this]{ return enabled; }); // release mtx, suspend thread execution until enabled becomes true
+                }
                 auto k = Get();
                 Notify(k);
             }
@@ -205,10 +224,13 @@ class LinuxKeyboard : public InputDevice
         tcsetattr(STDIN_FILENO, TCSANOW, &oldt);
     }
 
+    bool enabled;
     termios oldt;
     termios newt;
     InputSource is;
     std::thread servant;
+    std::mutex mtx;
+    std::condition_variable cv;
 };
 
 } // namespace detail