_relative positioning fix

Source/Engine/Platform/SDL/SDLWindow.cpp

@@ -48,8 +48,9 @@ namespace
 
 void* GetNativeWindowPointer(SDL_Window* window);
 SDL_HitTestResult OnWindowHitTest(SDL_Window* win, const SDL_Point* area, void* data);
-
-void SetSDLWindowScreenPosition(SDLWindow* window, const int x, const int y);
+void GetRelativeWindowOffset(WindowType type, SDLWindow* parentWindow, Int2& positionOffset);
+Int2 GetSDLWindowScreenPosition(const SDLWindow* window);
+void SetSDLWindowScreenPosition(const SDLWindow* window, const int x, const int y);
 
 class SDLDropFilesData : public IGuiData
 {
@@ -97,13 +98,8 @@ SDLWindow::SDLWindow(const CreateWindowSettings& settings)
     , _dragOver(false)
 #endif
 {
-    int32 x = Math::TruncToInt(settings.Position.X);
-    int32 y = Math::TruncToInt(settings.Position.Y);
-    int32 clientWidth = Math::TruncToInt(settings.Size.X);
-    int32 clientHeight = Math::TruncToInt(settings.Size.Y);
-    int32 windowWidth = clientWidth;
-    int32 windowHeight = clientHeight;
-    _clientSize = Float2((float)clientWidth, (float)clientHeight);
+    Int2 clientSize(Math::TruncToInt(settings.Size.X), Math::TruncToInt(settings.Size.Y));
+    _clientSize = Float2(clientSize);
 
     if (SDLPlatform::UsesWayland())
     {
@@ -154,16 +150,18 @@ SDLWindow::SDLWindow(const CreateWindowSettings& settings)
         }
 #endif
     }
-    
-    // It should be noted that SDL creates the window in client-space coordinates (ignoring window decorations)
+
+    // The window position needs to be relative to the parent window
+    Int2 relativePosition(Math::TruncToInt(settings.Position.X), Math::TruncToInt(settings.Position.Y));
+    GetRelativeWindowOffset(_settings.Type, _settings.Parent, relativePosition);
 
     SDL_PropertiesID props = SDL_CreateProperties();
     SDL_SetNumberProperty(props, SDL_PROP_WINDOW_CREATE_FLAGS_NUMBER, flags);
     SDL_SetStringProperty(props, SDL_PROP_WINDOW_CREATE_TITLE_STRING, settings.Title.ToStringAnsi().Get());
-    SDL_SetNumberProperty(props, SDL_PROP_WINDOW_CREATE_X_NUMBER, x);
-    SDL_SetNumberProperty(props, SDL_PROP_WINDOW_CREATE_Y_NUMBER, y);
-    SDL_SetNumberProperty(props, SDL_PROP_WINDOW_CREATE_WIDTH_NUMBER, windowWidth);
-    SDL_SetNumberProperty(props, SDL_PROP_WINDOW_CREATE_HEIGHT_NUMBER, windowHeight);
+    SDL_SetNumberProperty(props, SDL_PROP_WINDOW_CREATE_X_NUMBER, relativePosition.X);
+    SDL_SetNumberProperty(props, SDL_PROP_WINDOW_CREATE_Y_NUMBER, relativePosition.Y);
+    SDL_SetNumberProperty(props, SDL_PROP_WINDOW_CREATE_WIDTH_NUMBER, clientSize.X);
+    SDL_SetNumberProperty(props, SDL_PROP_WINDOW_CREATE_HEIGHT_NUMBER, clientSize.Y);
     SDL_SetBooleanProperty(props, SDL_PROP_WINDOW_CREATE_EXTERNAL_GRAPHICS_CONTEXT_BOOLEAN, true);
     if ((flags & SDL_WINDOW_TOOLTIP) != 0)
         SDL_SetBooleanProperty(props, SDL_PROP_WINDOW_CREATE_TOOLTIP_BOOLEAN, true);
@@ -192,10 +190,10 @@ SDLWindow::SDLWindow(const CreateWindowSettings& settings)
 
     SDL_DisplayID display = SDL_GetDisplayForWindow(_window);
     _dpiScale = SDL_GetWindowDisplayScale(_window);
-    _dpi = (int)(_dpiScale * DefaultDPI);
+    _dpi = Math::TruncToInt(_dpiScale * DefaultDPI);
 
-    SDL_SetWindowMinimumSize(_window, (int)_settings.MinimumSize.X, (int)_settings.MinimumSize.Y);
-    SDL_SetWindowMaximumSize(_window, (int)_settings.MaximumSize.X, (int)_settings.MaximumSize.Y);
+    SDL_SetWindowMinimumSize(_window, Math::TruncToInt(_settings.MinimumSize.X), Math::TruncToInt(_settings.MinimumSize.Y));
+    SDL_SetWindowMaximumSize(_window, Math::TruncToInt(_settings.MaximumSize.X), Math::TruncToInt(_settings.MaximumSize.Y));
     
     SDL_SetWindowHitTest(_window, &OnWindowHitTest, this);
     InitSwapChain();
@@ -857,7 +855,42 @@ void SDLWindow::SetClientBounds(const Rectangle& clientArea)
     SDL_SetWindowSize(_window, newW, newH);
 }
 
-void SetSDLWindowScreenPosition(SDLWindow* window, const int x, const int y)
+bool IsPopupWindow(WindowType type)
+{
+    return type == WindowType::Popup || type == WindowType::Tooltip;
+}
+
+void GetRelativeWindowOffset(WindowType type, SDLWindow* parentWindow, Int2& positionOffset)
+{
+    if (!IsPopupWindow(type))
+        return;
+
+    SDLWindow* window = parentWindow;
+    while (window != nullptr)
+    {
+        Int2 parentPosition;
+        SDL_GetWindowPosition(window->GetSDLWindow(), &parentPosition.X, &parentPosition.Y);
+        positionOffset -= parentPosition;
+
+        if (!IsPopupWindow(window->GetSettings().Type))
+            break;
+
+        window = window->GetSettings().Parent;
+    }
+}
+
+Int2 GetSDLWindowScreenPosition(const SDLWindow* window)
+{
+    Int2 relativeOffset(0, 0);
+    GetRelativeWindowOffset(window->GetSettings().Type, window->GetSettings().Parent, relativeOffset);
+    
+    Int2 position;
+    SDL_GetWindowPosition(window->GetSDLWindow(), &position.X, &position.Y);
+
+    return position - relativeOffset;
+}
+
+void SetSDLWindowScreenPosition(const SDLWindow* window, const int x, const int y)
 {
 #if PLATFORM_LINUX
     /*if (SDLPlatform::UsesWayland())
@@ -868,7 +901,9 @@ void SetSDLWindowScreenPosition(SDLWindow* window, const int x, const int y)
             return;
     }*/
 #endif
-    SDL_SetWindowPosition(window->GetSDLWindow(), x, y);
+    Int2 relativePosition(x, y);
+    GetRelativeWindowOffset(window->GetSettings().Type, window->GetSettings().Parent, relativePosition);
+    SDL_SetWindowPosition(window->GetSDLWindow(), relativePosition.X, relativePosition.Y);
 }
 
 void SDLWindow::SetPosition(const Float2& position)
@@ -911,8 +946,7 @@ Float2 SDLWindow::GetPosition() const
     Int2 topLeftBorder;
     SDL_GetWindowBordersSize(_window, &topLeftBorder.Y, &topLeftBorder.X, nullptr, nullptr);
 
-    Int2 position;
-    SDL_GetWindowPosition(_window, &position.X, &position.Y);
+    Int2 position = GetSDLWindowScreenPosition(this);
     position -= topLeftBorder;
     
     return Float2(static_cast<float>(position.X), static_cast<float>(position.Y));
@@ -938,17 +972,13 @@ Float2 SDLWindow::GetClientSize() const
 
 Float2 SDLWindow::ScreenToClient(const Float2& screenPos) const
 {
-    Int2 position;
-    SDL_GetWindowPosition(_window, &position.X, &position.Y);
-    
+    Int2 position = GetSDLWindowScreenPosition(this);
     return screenPos - Float2(static_cast<float>(position.X), static_cast<float>(position.Y));
 }
 
 Float2 SDLWindow::ClientToScreen(const Float2& clientPos) const
 {
-    Int2 position;
-    SDL_GetWindowPosition(_window, &position.X, &position.Y);
-
+    Int2 position = GetSDLWindowScreenPosition(this);
     return clientPos + Float2(static_cast<float>(position.X), static_cast<float>(position.Y));
 }
 
@@ -1103,7 +1133,7 @@ void SDLWindow::UpdateCursor()
 {
     if (_cursor == CursorType::Hidden)
     {
-        SDL_HideCursor();
+        //SDL_HideCursor();
 
         if (_isTrackingMouse)
             Input::Mouse->SetRelativeMode(true, this);