From 7afbc443c932678c0a61f70ce1c767c9f2fc6e17 Mon Sep 17 00:00:00 2001
From: BlackMark <me@blackmark.me>
Date: Sun, 5 Jul 2020 16:56:27 +0200
Subject: [PATCH] Implement monitor enumeration

---
 AdaptiveBrightness/monitor.hpp             | 34 ++++++++++++++-
 AdaptiveBrightness/monitor_control_win.cpp | 49 +++++++++++++++++++++-
 AdaptiveBrightness/monitor_win.cpp         |  2 +-
 CMakeLists.txt                             |  6 +++
 4 files changed, 88 insertions(+), 3 deletions(-)

diff --git a/AdaptiveBrightness/monitor.hpp b/AdaptiveBrightness/monitor.hpp
index 5965b45..828f8b0 100644
--- a/AdaptiveBrightness/monitor.hpp
+++ b/AdaptiveBrightness/monitor.hpp
@@ -1,8 +1,40 @@
 #pragma once
 
+#ifdef _MSC_VER
+
+    #include <vector>
+
+    #include <physicalmonitorenumerationapi.h>
+    #include <windows.h>
+
+namespace detail {
+
+extern BOOL enumMonitorsCallback(HMONITOR, HDC, LPRECT, LPARAM);
+
+} // namespace detail
+
 class Monitor {
+  public:
+    Monitor() = delete;
+
   private:
+    friend BOOL detail::enumMonitorsCallback(HMONITOR, HDC, LPRECT, LPARAM);
+
+    Monitor(HMONITOR hMonitor, PHYSICAL_MONITOR hPhysicalMonitor);
+
+    const HMONITOR m_hMonitor;
+    const PHYSICAL_MONITOR m_physicalMonitor;
+};
+
+#endif
+
+#if defined(__clang__) || defined(__GNUC__)
+
+class Monitor {
+  public:
     Monitor();
 
-  public:
+  private:
 };
+
+#endif
diff --git a/AdaptiveBrightness/monitor_control_win.cpp b/AdaptiveBrightness/monitor_control_win.cpp
index 6334010..9db8da7 100644
--- a/AdaptiveBrightness/monitor_control_win.cpp
+++ b/AdaptiveBrightness/monitor_control_win.cpp
@@ -2,9 +2,56 @@
 
 #ifdef _MSC_VER
 
-std::vector<Monitor> enumerateMonitors()
+    #include <QString>
+    #include <QtDebug>
+    #include <QtGlobal>
+
+    #include "log_tr.hpp"
+
+namespace detail {
+
+static QString getLastErrorString()
 {
+    DWORD lastErrorId = GetLastError();
+
     return {};
 }
 
+static BOOL enumMonitorsCallback(HMONITOR hMonitor, [[maybe_unused]] HDC hDC, [[maybe_unused]] LPRECT lpRect, LPARAM lParam)
+{
+    std::vector<Monitor>& monitors = *reinterpret_cast<std::vector<Monitor>*>(lParam);
+    DWORD numMonitors;
+
+    if(!GetNumberOfPhysicalMonitorsFromHMONITOR(hMonitor, &numMonitors)) {
+        qCritical(ltr("Unable to get number of physical monitors from handle, error: %1").arg(detail::getLastErrorString()));
+        return true; // Continue enumerating
+    }
+
+    std::vector<PHYSICAL_MONITOR> physicalMonitors(numMonitors);
+
+    if(!GetPhysicalMonitorsFromHMONITOR(hMonitor, numMonitors, physicalMonitors.data())) {
+        qCritical(ltr("Unable to get physical monitors from handle, error: %1").arg(detail::getLastErrorString()));
+        return true; // Continue enumerating
+    }
+
+    for(const auto& physicalMonitor: physicalMonitors) {
+        monitors.push_back(Monitor(hMonitor, physicalMonitor));
+    }
+
+    return true;
+}
+
+} // namespace detail
+
+std::vector<Monitor> enumerateMonitors()
+{
+    std::vector<Monitor> monitors;
+
+    if(!EnumDisplayMonitors(nullptr, nullptr, detail::enumMonitorsCallback, reinterpret_cast<LPARAM>(&monitors))) {
+        qCritical(ltr("Unable to enumerate display monitors, error: %1").arg(detail::getLastErrorString()));
+    }
+
+    return monitors;
+}
+
 #endif
diff --git a/AdaptiveBrightness/monitor_win.cpp b/AdaptiveBrightness/monitor_win.cpp
index 89aded6..3383f9e 100644
--- a/AdaptiveBrightness/monitor_win.cpp
+++ b/AdaptiveBrightness/monitor_win.cpp
@@ -2,6 +2,6 @@
 
 #ifdef _MSC_VER
 
-Monitor::Monitor() {}
+Monitor::Monitor(HMONITOR hMonitor, PHYSICAL_MONITOR hPhysicalMonitor) : m_hMonitor(hMonitor), m_physicalMonitor(m_physicalMonitor) {}
 
 #endif
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 596f9b7..1adae54 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -71,6 +71,12 @@ target_link_libraries(AdaptiveBrightness
                       Qt5::SerialPort
 )
 
+if(MSVC)
+target_link_libraries(AdaptiveBrightness
+                      Dxva2.lib
+)
+endif()
+
 if(MSVC)
     get_target_property(QT5_QMAKE_EXECUTABLE Qt5::qmake IMPORTED_LOCATION)
     get_filename_component(QT5_WINDEPLOYQT_EXECUTABLE ${QT5_QMAKE_EXECUTABLE} PATH)