From a141bbbea503ae7b320eba614a80ca2f4e5c1cba Mon Sep 17 00:00:00 2001
From: Vaxry <vaxry@vaxry.net>
Date: Sun, 21 Apr 2024 01:47:24 +0100
Subject: [PATCH] helpers: Add new C++ Signal and Listener classes

A memory-safe alternative to wl_signal
---
 src/helpers/signal/Listener.cpp | 13 +++++++++++++
 src/helpers/signal/Listener.hpp | 24 ++++++++++++++++++++++++
 src/helpers/signal/Signal.cpp   | 22 ++++++++++++++++++++++
 src/helpers/signal/Signal.hpp   | 19 +++++++++++++++++++
 4 files changed, 78 insertions(+)
 create mode 100644 src/helpers/signal/Listener.cpp
 create mode 100644 src/helpers/signal/Listener.hpp
 create mode 100644 src/helpers/signal/Signal.cpp
 create mode 100644 src/helpers/signal/Signal.hpp

diff --git a/src/helpers/signal/Listener.cpp b/src/helpers/signal/Listener.cpp
new file mode 100644
index 00000000..ae506343
--- /dev/null
+++ b/src/helpers/signal/Listener.cpp
@@ -0,0 +1,13 @@
+#include "Listener.hpp"
+#include "Signal.hpp"
+
+CSignalListener::CSignalListener(std::function<void(std::any)> handler) : m_fHandler(handler) {
+    ;
+}
+
+void CSignalListener::emit(std::any data) {
+    if (!m_fHandler)
+        return;
+
+    m_fHandler(data);
+}
diff --git a/src/helpers/signal/Listener.hpp b/src/helpers/signal/Listener.hpp
new file mode 100644
index 00000000..d2edb253
--- /dev/null
+++ b/src/helpers/signal/Listener.hpp
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <any>
+#include <memory>
+#include <functional>
+
+class CSignal;
+
+class CSignalListener {
+  public:
+    CSignalListener(std::function<void(std::any)> handler);
+
+    CSignalListener(CSignalListener&&)       = delete;
+    CSignalListener(CSignalListener&)        = delete;
+    CSignalListener(const CSignalListener&)  = delete;
+    CSignalListener(const CSignalListener&&) = delete;
+
+    void emit(std::any data);
+
+  private:
+    std::function<void(std::any)> m_fHandler;
+};
+
+typedef std::shared_ptr<CSignalListener> CHyprSignalListener;
diff --git a/src/helpers/signal/Signal.cpp b/src/helpers/signal/Signal.cpp
new file mode 100644
index 00000000..a8adc275
--- /dev/null
+++ b/src/helpers/signal/Signal.cpp
@@ -0,0 +1,22 @@
+#include "Signal.hpp"
+#include <algorithm>
+
+void CSignal::emit(std::any data) {
+    bool dirty = false;
+
+    for (auto& l : m_vListeners) {
+        if (const CHyprSignalListener L = l.lock())
+            L->emit(data);
+        else
+            dirty = true;
+    }
+
+    if (dirty)
+        std::erase_if(m_vListeners, [](const auto& other) { return !other.lock(); });
+}
+
+CHyprSignalListener CSignal::registerListener(std::function<void(std::any)> handler) {
+    CHyprSignalListener listener = std::make_shared<CSignalListener>(handler);
+    m_vListeners.emplace_back(std::weak_ptr<CSignalListener>(listener));
+    return listener;
+}
diff --git a/src/helpers/signal/Signal.hpp b/src/helpers/signal/Signal.hpp
new file mode 100644
index 00000000..38f9ea0c
--- /dev/null
+++ b/src/helpers/signal/Signal.hpp
@@ -0,0 +1,19 @@
+#pragma once
+
+#include <functional>
+#include <any>
+#include <vector>
+#include <memory>
+
+#include "Listener.hpp"
+
+class CSignal {
+  public:
+    void emit(std::any data);
+
+    //
+    [[nodiscard("Listener is unregistered when the ptr is lost")]] CHyprSignalListener registerListener(std::function<void(std::any)> handler);
+
+  private:
+    std::vector<std::weak_ptr<CSignalListener>> m_vListeners;
+};