Show Popup on missing game files

extras/videoDrivers/SDL2/VideoSDL2.cpp

@@ -223,6 +223,12 @@
     boost::nowide::cerr << msg << std::endl;
 }
 
+void VideoSDL2::ShowErrorMessage(const std::string& title, const std::string& message)
+{
+    // window==nullptr is okay too ("no parent")
+    SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, title.c_str(), message.c_str(), window);
+}
+
 void VideoSDL2::HandlePaste()
 {
     if(!SDL_HasClipboardText())

extras/videoDrivers/SDL2/VideoSDL2.h

@@ -34,6 +34,8 @@ class VideoSDL2 final : public VideoDriver
 
     bool MessageLoop() override;
 
+    void ShowErrorMessage(const std::string& title, const std::string& message) override;
+
     /// Get a timestamp
     unsigned long GetTickCount() const override;
 

extras/videoDrivers/WinAPI/WinAPI.cpp

@@ -16,6 +16,7 @@
 #include <cstring>
 #include <iostream>
 #include <limits>
+#include <winuser.h>
 
 /**
  *  Zeiger auf die aktuelle Instanz.
@@ -443,6 +444,11 @@ bool VideoWinAPI::MessageLoop()
     return true;
 }
 
+void VideoWinAPI::ShowErrorMessage(const std::string& title, const std::string& message)
+{
+    MessageBoxA(nullptr, message.c_str(), title.c_str(), MB_OK | MB_ICONEXCLAMATION);
+}
+
 /**
  *  Funktion zum Auslesen des TickCounts.
  *

extras/videoDrivers/WinAPI/WinAPI.h

@@ -44,6 +44,9 @@ class VideoWinAPI final : public VideoDriver
     /// Die Nachrichtenschleife.
     bool MessageLoop() override;
 
+    /// Popup Window
+    void ShowErrorMessage(const std::string& title, const std::string& message) override;
+
     /// Funktion zum Auslesen des TickCounts.
     unsigned long GetTickCount() const override;
 

libs/driver/include/driver/VideoInterface.h

@@ -72,6 +72,9 @@ class BOOST_SYMBOL_VISIBLE IVideoDriver
     virtual bool IsInitialized() const = 0;
     /// Shall we support OpenGL? (Disabled for tests)
     virtual bool IsOpenGL() const = 0;
+
+    // Display the problem to the gamer
+    virtual void ShowErrorMessage(const std::string& title, const std::string& message) = 0;
 };
 
 class VideoDriverLoaderInterface;

libs/s25main/desktops/dskSplash.cpp

@@ -12,12 +12,14 @@
 #include "WindowManager.h"
 #include "controls/ctrlTimer.h"
 #include "dskMainMenu.h"
+#include "helpers/format.hpp"
 #include "ingameWindows/iwMusicPlayer.h"
 #include "mygettext/mygettext.h"
 #include "ogl/glArchivItem_Bitmap.h"
 #include "gameData/ApplicationLoader.h"
 #include "s25util/Log.h"
 #include "s25util/error.h"
+#include <drivers/VideoDriverWrapper.h>
 
 using namespace std::chrono_literals;
 
@@ -76,9 +78,14 @@
 
     } else
     {
-        s25util::error(_("Some files failed to load.\n"
-                         "Please ensure that the Settlers 2 Gold-Edition is installed \n"
-                         "in the same directory as Return to the Roots."));
+        const auto fmt = boost::format(_("Some essential game files failed to load.\n"
+                                         "Please ensure that the Settlers 2 Gold-Edition is installed in\n"
+                                         "%1%"))
+                         % RTTRCONFIG.ExpandPath("<RTTR_GAME>").string();
+
+        s25util::error(fmt.str());
+        VIDEODRIVER.ShowErrorMessage(_("Missing game files"), fmt.str());
+
         GLOBALVARS.notdone = false;
     }
 }

libs/s25main/drivers/VideoDriverWrapper.cpp

@@ -180,6 +180,12 @@
     return true;
 }
 
+void VideoDriverWrapper::ShowErrorMessage(const std::string& title, const std::string& message)
+{
+    if(videodriver)
+        videodriver->ShowErrorMessage(title, message);
+}
+
 void VideoDriverWrapper::setTargetFramerate(int target)
 {
     frameLimiter_->setTargetFramerate(target);

libs/s25main/drivers/VideoDriverWrapper.h

@@ -81,6 +81,8 @@ class VideoDriverWrapper : public Singleton<VideoDriverWrapper, SingletonPolicie
     // Nachrichtenschleife
     bool Run();
 
+    void ShowErrorMessage(const std::string& title, const std::string& message);
+
     unsigned GetTickCount();
     /// Set framerate target (FPS)
     /// negative for unlimited, 0 for hardware VSync

tests/mockupDrivers/MockupVideoDriver.cpp

@@ -4,6 +4,7 @@
 
 #include "MockupVideoDriver.h"
 #include <boost/nowide/iostream.hpp>
+#include <iostream>
 
 MockupVideoDriver::MockupVideoDriver(VideoDriverLoaderInterface* CallBack) : VideoDriver(CallBack), tickCount_(1)
 {
@@ -81,3 +82,8 @@ void* MockupVideoDriver::GetMapPointer() const
 {
     return nullptr;
 }
+
+void MockupVideoDriver::ShowErrorMessage(const std::string& title, const std::string& message)
+{
+    std::cerr << title << ": " << message << std::endl;
+}

tests/mockupDrivers/MockupVideoDriver.h

@@ -25,6 +25,7 @@ class MockupVideoDriver : public VideoDriver
     KeyEvent GetModKeyState() const override;
     void* GetMapPointer() const override;
     bool IsOpenGL() const override { return false; }
+    void ShowErrorMessage(const std::string& title, const std::string& message) override;
     using VideoDriver::FindClosestVideoMode;
 
     KeyEvent modKeyState_;