Platform: Added platform_io.Platform_SetWindowFocus, Platform_GetWindowFocus function wrappers (unused yet). Exact specs tbd because our simplified concept of focus doesn't necessary match the more complex OS native concepts. (#1542)

examples/directx11_example/main.cpp

@@ -144,10 +144,9 @@ int main(int, char**)
     ImGui_ImplDX11_Init(g_pd3dDevice, g_pd3dDeviceContext);
 
     // Setup style
+    ImGui::GetStyle().WindowRounding = 0.0f;
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
-    ImGuiStyle& style = ImGui::GetStyle();
-    style.WindowRounding = 0.0f;
 
     // Load Fonts
     // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them. 

examples/imgui_impl_glfw.cpp

@@ -477,6 +477,18 @@ static void ImGui_ImplGlfw_SetWindowTitle(ImGuiViewport* viewport, const char* t
     glfwSetWindowTitle(data->Window, title);
 }
 
+static void ImGui_ImplGlfw_SetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataGlfw* data = (ImGuiViewportDataGlfw*)viewport->PlatformUserData;
+    glfwFocusWindow(data->Window);
+}
+
+static bool ImGui_ImplGlfw_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataGlfw* data = (ImGuiViewportDataGlfw*)viewport->PlatformUserData;
+    return glfwGetWindowAttrib(data->Window, GLFW_FOCUSED) != 0;
+}
+
 #if GLFW_HAS_WINDOW_ALPHA
 static void ImGui_ImplGlfw_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
 {
@@ -587,6 +599,8 @@ static void ImGui_ImplGlfw_InitPlatformInterface()
     platform_io.Platform_GetWindowPos = ImGui_ImplGlfw_GetWindowPos;
     platform_io.Platform_SetWindowSize = ImGui_ImplGlfw_SetWindowSize;
     platform_io.Platform_GetWindowSize = ImGui_ImplGlfw_GetWindowSize;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplGlfw_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplGlfw_GetWindowFocus;
     platform_io.Platform_SetWindowTitle = ImGui_ImplGlfw_SetWindowTitle;
     platform_io.Platform_RenderWindow = ImGui_ImplGlfw_RenderWindow;
     platform_io.Platform_SwapBuffers = ImGui_ImplGlfw_SwapBuffers;

examples/imgui_impl_sdl2.cpp

@@ -409,6 +409,19 @@ static void ImGui_ImplSDL2_SetWindowTitle(ImGuiViewport* viewport, const char* t
     SDL_SetWindowTitle(data->Window, title);
 }
 
+static void ImGui_ImplSDL2_SetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataSDL2* data = (ImGuiViewportDataSDL2*)viewport->PlatformUserData;
+    SDL_RaiseWindow(data->Window);
+}
+
+static bool ImGui_ImplSDL2_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataSDL2* data = (ImGuiViewportDataSDL2*)viewport->PlatformUserData;
+    bool focus = (SDL_GetWindowFlags(data->Window) & SDL_WINDOW_INPUT_FOCUS) != 0;
+    return focus;
+}
+
 static void ImGui_ImplSDL2_RenderWindow(ImGuiViewport* viewport, void*)
 {
     ImGuiViewportDataSDL2* data = (ImGuiViewportDataSDL2*)viewport->PlatformUserData;
@@ -478,6 +491,8 @@ static void ImGui_ImplSDL2_InitPlatformInterface(SDL_Window* window, void* sdl_g
     platform_io.Platform_GetWindowPos = ImGui_ImplSDL2_GetWindowPos;
     platform_io.Platform_SetWindowSize = ImGui_ImplSDL2_SetWindowSize;
     platform_io.Platform_GetWindowSize = ImGui_ImplSDL2_GetWindowSize;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplSDL2_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplSDL2_GetWindowFocus;
     platform_io.Platform_SetWindowTitle = ImGui_ImplSDL2_SetWindowTitle;
     platform_io.Platform_RenderWindow = ImGui_ImplSDL2_RenderWindow;
     platform_io.Platform_SwapBuffers = ImGui_ImplSDL2_SwapBuffers;

examples/imgui_impl_win32.cpp

@@ -502,6 +502,22 @@ static void ImGui_ImplWin32_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
     ::SetWindowPos(data->Hwnd, NULL, 0, 0, rect.right - rect.left, rect.bottom - rect.top, SWP_NOZORDER | SWP_NOMOVE | SWP_NOACTIVATE);
 }
 
+static void ImGui_ImplWin32_SetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData;
+    IM_ASSERT(data->Hwnd != 0);
+    ::BringWindowToTop(data->Hwnd);
+    ::SetForegroundWindow(data->Hwnd);
+    ::SetFocus(data->Hwnd);
+}
+
+static bool ImGui_ImplWin32_GetWindowFocus(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData;
+    IM_ASSERT(data->Hwnd != 0);
+    return ::GetActiveWindow() == data->Hwnd;
+}
+
 static void ImGui_ImplWin32_SetWindowTitle(ImGuiViewport* viewport, const char* title)
 {
     ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData;
@@ -642,6 +658,8 @@ static void ImGui_ImplWin32_InitPlatformInterface()
     platform_io.Platform_GetWindowPos = ImGui_ImplWin32_GetWindowPos;
     platform_io.Platform_SetWindowSize = ImGui_ImplWin32_SetWindowSize;
     platform_io.Platform_GetWindowSize = ImGui_ImplWin32_GetWindowSize;
+    platform_io.Platform_SetWindowFocus = ImGui_ImplWin32_SetWindowFocus;
+    platform_io.Platform_GetWindowFocus = ImGui_ImplWin32_GetWindowFocus;
     platform_io.Platform_SetWindowTitle = ImGui_ImplWin32_SetWindowTitle;
     platform_io.Platform_SetWindowAlpha = ImGui_ImplWin32_SetWindowAlpha;
     platform_io.Platform_GetWindowDpiScale = ImGui_ImplWin32_GetWindowDpiScale;

examples/opengl3_example/main.cpp

@@ -37,13 +37,15 @@ int main(int, char**)
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;
     io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoTaskBarIcons;
-    //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
+    //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoMerge;
+    io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;   // Enable Gamepad Controls
 
     ImGui_ImplGlfw_InitForOpenGL(window, true);
     ImGui_ImplOpenGL3_Init();
 
     // Setup style
+    ImGui::GetStyle().WindowRounding = 0.0f;
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 

imgui.h

@@ -1899,6 +1899,8 @@ struct ImGuiPlatformIO
     ImVec2  (*Platform_GetWindowPos)(ImGuiViewport* vp);
     void    (*Platform_SetWindowSize)(ImGuiViewport* vp, ImVec2 size);
     ImVec2  (*Platform_GetWindowSize)(ImGuiViewport* vp);
+    void    (*Platform_SetWindowFocus)(ImGuiViewport* vp);                  // Move window to front and set input focus
+    bool    (*Platform_GetWindowFocus)(ImGuiViewport* vp);
     void    (*Platform_SetWindowTitle)(ImGuiViewport* vp, const char* title);
     void    (*Platform_SetWindowAlpha)(ImGuiViewport* vp, float alpha);     // (Optional) Setup window transparency
     void    (*Platform_RenderWindow)(ImGuiViewport* vp, void* render_arg);  // (Optional) Setup for render (platform side)