[feat] add display selection method for Windows platform

src/screen_capturer/screen_capturer.h

@@ -11,7 +11,18 @@
 
 class ScreenCapturer {
  public:
-  typedef std::function<void(unsigned char *, int, int, int)> cb_desktop_data;
+  typedef std::function<void(unsigned char*, int, int, int)> cb_desktop_data;
+
+  class DisplayInfo {
+   public:
+    void* handle = nullptr;
+    std::string name = "";
+    bool is_primary = false;
+    int left = 0;
+    int top = 0;
+    int right = 0;
+    int bottom = 0;
+  };
 
  public:
   virtual ~ScreenCapturer() {}
@@ -21,6 +32,8 @@ class ScreenCapturer {
   virtual int Destroy() = 0;
   virtual int Start() = 0;
   virtual int Stop() = 0;
+
+  virtual std::vector<DisplayInfo> GetDisplayList() = 0;
 };
 
 #endif

src/screen_capturer/windows/screen_capturer_wgc.cpp

@@ -8,17 +8,36 @@
 #include <iostream>
 
 #include "libyuv.h"
+#include "rd_log.h"
+
+static std::vector<ScreenCapturer::DisplayInfo> gs_display_list;
+
+std::string WideToUtf8(const wchar_t *wideStr) {
+  int size_needed = WideCharToMultiByte(CP_UTF8, 0, wideStr, -1, nullptr, 0,
+                                        nullptr, nullptr);
+  std::string result(size_needed, 0);
+  WideCharToMultiByte(CP_UTF8, 0, wideStr, -1, &result[0], size_needed, nullptr,
+                      nullptr);
+  result.pop_back();
+  return result;
+}
 
 BOOL WINAPI EnumMonitorProc(HMONITOR hmonitor, [[maybe_unused]] HDC hdc,
                             [[maybe_unused]] LPRECT lprc, LPARAM data) {
-  MONITORINFOEX info_ex;
-  info_ex.cbSize = sizeof(MONITORINFOEX);
+  MONITORINFOEX monitor_info_;
+  monitor_info_.cbSize = sizeof(MONITORINFOEX);
 
-  GetMonitorInfo(hmonitor, &info_ex);
+  if (GetMonitorInfo(hmonitor, &monitor_info_)) {
+    gs_display_list.push_back(
+        {(void *)hmonitor, WideToUtf8(monitor_info_.szDevice),
+         (monitor_info_.dwFlags & MONITORINFOF_PRIMARY) ? true : false,
+         monitor_info_.rcMonitor.left, monitor_info_.rcMonitor.top,
+         monitor_info_.rcMonitor.right, monitor_info_.rcMonitor.bottom});
+  }
 
-  if (info_ex.dwFlags == DISPLAY_DEVICE_MIRRORING_DRIVER) return true;
+  if (monitor_info_.dwFlags == DISPLAY_DEVICE_MIRRORING_DRIVER) return true;
 
-  if (info_ex.dwFlags & MONITORINFOF_PRIMARY) {
+  if (monitor_info_.dwFlags & MONITORINFOF_PRIMARY) {
     *(HMONITOR *)data = hmonitor;
   }
 
@@ -28,12 +47,13 @@ BOOL WINAPI EnumMonitorProc(HMONITOR hmonitor, [[maybe_unused]] HDC hdc,
 HMONITOR GetPrimaryMonitor() {
   HMONITOR hmonitor = nullptr;
 
+  gs_display_list.clear();
   ::EnumDisplayMonitors(NULL, NULL, EnumMonitorProc, (LPARAM)&hmonitor);
 
   return hmonitor;
 }
 
-ScreenCapturerWgc::ScreenCapturerWgc() {}
+ScreenCapturerWgc::ScreenCapturerWgc() : monitor_(nullptr) {}
 
 ScreenCapturerWgc::~ScreenCapturerWgc() {
   Stop();
@@ -89,7 +109,17 @@ int ScreenCapturerWgc::Init(const int fps, cb_desktop_data cb) {
 
     session_->RegisterObserver(this);
 
-    error = session_->Initialize(GetPrimaryMonitor());
+    monitor_ = GetPrimaryMonitor();
+
+    display_list_ = gs_display_list;
+
+    for (const auto &display : display_list_) {
+      LOG_INFO("Display Name: {}, Is Primary: {}, Bounds: ({}, {}) - ({}, {})",
+               display.name, (display.is_primary ? "Yes" : "No"), display.left,
+               display.top, display.right, display.bottom);
+    }
+
+    error = session_->Initialize(monitor_);
 
     _inited = true;
   } while (0);
@@ -139,6 +169,44 @@ int ScreenCapturerWgc::Stop() {
   return 0;
 }
 
+int ScreenCapturerWgc::SwitchTo(int monitor_index) {
+  if (!_inited) return -1;
+  if (monitor_index >= display_list_.size()) {
+    LOG_ERROR("Invalid monitor index: {}", monitor_index);
+    return -3;
+  }
+
+  LOG_INFO("Switching to monitor {}:{}", monitor_index,
+           display_list_[monitor_index].name);
+
+  Stop();
+
+  if (session_) {
+    session_->Release();
+    delete session_;
+    session_ = nullptr;
+  }
+
+  session_ = new WgcSessionImpl();
+  if (!session_) {
+    LOG_ERROR("Failed to create new WgcSessionImpl.");
+    return -4;
+  }
+
+  session_->RegisterObserver(this);
+
+  int err = session_->Initialize((HMONITOR)display_list_[monitor_index].handle);
+  if (err != 0) {
+    LOG_ERROR("Failed to re-initialize session on new monitor.");
+    return -5;
+  }
+
+  monitor_ = (HMONITOR)display_list_[monitor_index].handle;
+  _inited = true;
+
+  return Start();
+}
+
 void ConvertABGRtoBGRA(const uint8_t *abgr_data, uint8_t *bgra_data, int width,
                        int height, int abgr_stride, int bgra_stride) {
   for (int i = 0; i < height; ++i) {

src/screen_capturer/windows/screen_capturer_wgc.h

@@ -5,6 +5,7 @@
 #include <functional>
 #include <string>
 #include <thread>
+#include <vector>
 
 #include "screen_capturer.h"
 #include "wgc_session.h"
@@ -27,11 +28,20 @@ class ScreenCapturerWgc : public ScreenCapturer,
   int Pause();
   int Resume();
 
+  std::vector<DisplayInfo> GetDisplayList() { return display_list_; }
+
+  int SwitchTo(int monitor_index);
+
   void OnFrame(const WgcSession::wgc_session_frame &frame);
 
  protected:
   void CleanUp();
 
+ private:
+  HMONITOR monitor_;
+  MONITORINFOEX monitor_info_;
+  std::vector<DisplayInfo> display_list_;
+
  private:
   WgcSession *session_ = nullptr;
 

src/screen_capturer/windows/wgc_session.h

@@ -33,7 +33,6 @@ class WgcSession {
   virtual int Pause() = 0;
   virtual int Resume() = 0;
 
- protected:
   virtual ~WgcSession(){};
 };
 

src/single_window/control_bar.cpp

@@ -80,6 +80,28 @@ int Render::ControlBar(std::shared_ptr<SubStreamWindowProperties>& props) {
           2.0f);
     }
 
+    // const char* items[] = {"1", "2", "3"};
+    // static int item_selected_idx = 0;
+    // ImGui::Text("Display:");
+    // ImGui::SameLine();
+    // ImGui::SetNextItemWidth(25.0f);
+    // ImGuiComboFlags flags =
+    //     ImGuiComboFlags_HeightSmall | ImGuiComboFlags_NoArrowButton;
+    // const char* combo_preview_value = items[item_selected_idx];
+    // ImGui::SetWindowFontScale(1.2f);
+    // if (ImGui::BeginCombo("##display", combo_preview_value, flags)) {
+    //   ImGui::SetWindowFontScale(0.5f);
+    //   for (int n = 0; n < IM_ARRAYSIZE(items); n++) {
+    //     const bool is_selected = (item_selected_idx == n);
+    //     if (ImGui::Selectable(items[n], is_selected)) item_selected_idx = n;
+
+    //     if (is_selected) ImGui::SetItemDefaultFocus();
+    //   }
+    //   ImGui::SetWindowFontScale(1.0f);
+    //   ImGui::EndCombo();
+    // }
+    // ImGui::SetWindowFontScale(1.0f);
+
     ImGui::SameLine();
     // audio capture button
     float disable_audio_x = ImGui::GetCursorScreenPos().x + 4;