Merge branch 'master' into viewport + specific changes for GLFW callbacks

# Conflicts:
#	examples/example_glfw_opengl3/main.cpp
#	examples/example_win32_directx11/main.cpp
#	examples/example_win32_directx9/main.cpp
#	examples/imgui_impl_glfw.cpp

docs/CHANGELOG.txt

@@ -78,7 +78,9 @@ Other Changes:
   in particular, points_count==0 could lead to a memory stomp if the draw list was previously empty.
 - Examples: DirectX10, DirectX11: Removed seemingly unnecessary calls to invalidate and recreate device objects
   in the WM_SIZE handler. (#2088) [@ice1000]
+- Examples: GLFW: User previously installed GLFW callbacks are now saved and chain-called by the default callbacks. (#1759)
 - Examples: OpenGL3+GLFW: Fixed error condition when using the GLAD loader. (#2157) [@blackball]
+- Examples: OpenGL3+GLFW/SDL: Made main.cpp compile with IMGUI_IMPL_OPENGL_LOADER_CUSTOM (may be missing init). (#2178) [@doug-moen]
 
 
 -----------------------------------------------------------------------

examples/example_allegro5/main.cpp

@@ -22,14 +22,16 @@ int main(int, char**)
     al_register_event_source(queue, al_get_keyboard_event_source());
     al_register_event_source(queue, al_get_mouse_event_source());
 
-    // Setup Dear ImGui binding
+    // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
+
+    // Setup Platform/Renderer bindings
     ImGui_ImplAllegro5_Init(display);
 
-    // Setup style
+    // Setup Style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 

examples/example_apple_opengl2/main.mm

@@ -237,16 +237,17 @@
     if ([view openGLContext] == nil)
         NSLog(@"No OpenGL Context!");
 
-    // Setup Dear ImGui binding
+    // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
 
+    // Setup Platform/Renderer bindings
     ImGui_ImplOSX_Init();
     ImGui_ImplOpenGL2_Init();
 
-    // Setup style
+    // Setup Style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 

examples/example_freeglut_opengl2/main.cpp

@@ -95,16 +95,17 @@ int main(int argc, char** argv)
     // otherwise it is possible to install our own functions and call the imgui_impl_freeglut.h functions ourselves.
     glutDisplayFunc(glut_display_func);
 
-    // Setup Dear ImGui binding
+    // Setup Dear ImGui context
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
 
+    // Setup Platform/Renderer bindings
     ImGui_ImplFreeGLUT_Init();
     ImGui_ImplFreeGLUT_InstallFuncs();
     ImGui_ImplOpenGL2_Init();
 
-    // Setup style
+    // Setup Style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 

examples/example_glfw_opengl2/main.cpp

@@ -36,7 +36,7 @@ int main(int, char**)
     glfwMakeContextCurrent(window);
     glfwSwapInterval(1); // Enable vsync
 
-    // Setup Dear ImGui binding
+    // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
@@ -46,10 +46,11 @@ int main(int, char**)
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoTaskBarIcons;
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoMerge;
 
+    // Setup Platform/Renderer bindings
     ImGui_ImplGlfw_InitForOpenGL(window, true);
     ImGui_ImplOpenGL2_Init();
 
-    // Setup style
+    // Setup Style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 

examples/example_glfw_opengl3/main.cpp

@@ -73,6 +73,8 @@ int main(int, char**)
     bool err = glewInit() != GLEW_OK;
 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
     bool err = gladLoadGL() == 0;
+#else
+    bool err = false; // If you use IMGUI_IMPL_OPENGL_LOADER_CUSTOM, your loader is likely to requires some form of initialization.
 #endif
     if (err)
     {
@@ -80,7 +82,7 @@ int main(int, char**)
         return 1;
     }
 
-    // Setup Dear ImGui binding
+    // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
@@ -90,10 +92,11 @@ int main(int, char**)
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoTaskBarIcons;
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoMerge;
 
+    // Setup Platform/Renderer bindings
     ImGui_ImplGlfw_InitForOpenGL(window, true);
     ImGui_ImplOpenGL3_Init(glsl_version);
 
-    // Setup style
+    // Setup Style
     ImGui::GetStyle().WindowRounding = 0.0f;
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();

examples/example_glfw_vulkan/main.cpp

@@ -350,7 +350,7 @@ int main(int, char**)
     ImGui_ImplVulkanH_WindowData* wd = &g_WindowData;
     SetupVulkanWindowData(wd, surface, w, h);
 
-    // Setup Dear ImGui binding
+    // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
@@ -360,10 +360,8 @@ int main(int, char**)
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoTaskBarIcons;
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoMerge;
 
-    // Setup GLFW binding
+    // Setup Platform/Renderer bindings
     ImGui_ImplGlfw_InitForVulkan(window, true);
-
-    // Setup Vulkan binding
     ImGui_ImplVulkan_InitInfo init_info = {};
     init_info.Instance = g_Instance;
     init_info.PhysicalDevice = g_PhysicalDevice;
@@ -376,7 +374,7 @@ int main(int, char**)
     init_info.CheckVkResultFn = check_vk_result;
     ImGui_ImplVulkan_Init(&init_info, wd->RenderPass);
 
-    // Setup style
+    // Setup Style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 

examples/example_marmalade/main.cpp

@@ -16,14 +16,16 @@ int main(int, char**)
 {
     IwGxInit();
 
-    // Setup Dear ImGui binding
+    // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
+
+    // Setup Platform/Renderer bindings
     ImGui_Marmalade_Init(true);
 
-    // Setup style
+    // Setup Style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 

examples/example_sdl_opengl2/main.cpp

@@ -34,7 +34,7 @@ int main(int, char**)
     SDL_GLContext gl_context = SDL_GL_CreateContext(window);
     SDL_GL_SetSwapInterval(1); // Enable vsync
 
-    // Setup Dear ImGui binding
+    // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
@@ -43,10 +43,11 @@ int main(int, char**)
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoTaskBarIcons;
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoMerge;
 
+    // Setup Platform/Renderer bindings
     ImGui_ImplSDL2_InitForOpenGL(window, gl_context);
     ImGui_ImplOpenGL2_Init();
 
-    // Setup style
+    // Setup Style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 

examples/example_sdl_opengl3/main.cpp

@@ -65,6 +65,8 @@ int main(int, char**)
     bool err = glewInit() != GLEW_OK;
 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
     bool err = gladLoadGL() == 0;
+#else
+    bool err = false; // If you use IMGUI_IMPL_OPENGL_LOADER_CUSTOM, your loader is likely to requires some form of initialization.
 #endif
     if (err)
     {
@@ -72,7 +74,7 @@ int main(int, char**)
         return 1;
     }
 
-    // Setup Dear ImGui binding
+    // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
@@ -81,10 +83,11 @@ int main(int, char**)
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoTaskBarIcons;
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoMerge;
 
+    // Setup Platform/Renderer bindings
     ImGui_ImplSDL2_InitForOpenGL(window, gl_context);
     ImGui_ImplOpenGL3_Init(glsl_version);
 
-    // Setup style
+    // Setup Style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 

examples/example_sdl_vulkan/main.cpp

@@ -333,7 +333,7 @@ int main(int, char**)
     ImGui_ImplVulkanH_WindowData* wd = &g_WindowData;
     SetupVulkanWindowData(wd, surface, w, h);
 
-    // Setup Dear ImGui binding
+    // Setup Dear ImGui context
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;       // Enable Keyboard Controls
@@ -341,10 +341,8 @@ int main(int, char**)
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoTaskBarIcons;
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoMerge;
 
-    // Setup SDL binding
+    // Setup Platform/Renderer bindings
     ImGui_ImplSDL2_InitForVulkan(window);
-
-    // Setup Vulkan binding
     ImGui_ImplVulkan_InitInfo init_info = {};
     init_info.Instance = g_Instance;
     init_info.PhysicalDevice = g_PhysicalDevice;
@@ -357,7 +355,7 @@ int main(int, char**)
     init_info.CheckVkResultFn = check_vk_result;
     ImGui_ImplVulkan_Init(&init_info, wd->RenderPass);
 
-    // Setup style
+    // Setup Style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 

examples/example_win32_directx10/main.cpp

@@ -112,7 +112,7 @@ int main(int, char**)
     ShowWindow(hwnd, SW_SHOWDEFAULT);
     UpdateWindow(hwnd);
 
-    // Setup Dear ImGui binding
+    // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
@@ -121,10 +121,11 @@ int main(int, char**)
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoTaskBarIcons;
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoMerge;
 
+    // Setup Platform/Renderer bindings
     ImGui_ImplWin32_Init(hwnd);
     ImGui_ImplDX10_Init(g_pd3dDevice);
 
-    // Setup style
+    // Setup Style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 

examples/example_win32_directx11/main.cpp

@@ -128,7 +128,7 @@ int main(int, char**)
     ShowWindow(hwnd, SW_SHOWDEFAULT);
     UpdateWindow(hwnd);
 
-    // Setup Dear ImGui binding
+    // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
@@ -140,10 +140,11 @@ int main(int, char**)
     io.ConfigFlags |= ImGuiConfigFlags_DpiEnableScaleFonts;     // FIXME-DPI: THIS CURRENTLY DOESN'T WORK AS EXPECTED. DON'T USE IN USER APP!
     io.ConfigFlags |= ImGuiConfigFlags_DpiEnableScaleViewports; // FIXME-DPI
 
+    // Setup Platform/Renderer bindings
     ImGui_ImplWin32_Init(hwnd);
     ImGui_ImplDX11_Init(g_pd3dDevice, g_pd3dDeviceContext);
 
-    // Setup style
+    // Setup Style
     ImGui::GetStyle().WindowRounding = 0.0f;
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();

examples/example_win32_directx12/main.cpp

@@ -286,7 +286,7 @@ int main(int, char**)
     ShowWindow(hwnd, SW_SHOWDEFAULT);
     UpdateWindow(hwnd);
 
-    // Setup Dear ImGui binding
+    // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
@@ -295,13 +295,14 @@ int main(int, char**)
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoTaskBarIcons;
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoMerge;
 
+    // Setup Platform/Renderer bindings
     ImGui_ImplWin32_Init(hwnd);
     ImGui_ImplDX12_Init(g_pd3dDevice, NUM_FRAMES_IN_FLIGHT, 
         DXGI_FORMAT_R8G8B8A8_UNORM,
         g_pd3dSrvDescHeap->GetCPUDescriptorHandleForHeapStart(), 
         g_pd3dSrvDescHeap->GetGPUDescriptorHandleForHeapStart());
 
-    // Setup style
+    // Setup Style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 

examples/example_win32_directx9/main.cpp

@@ -75,7 +75,7 @@ int main(int, char**)
         return 0;
     }
 
-    // Setup Dear ImGui binding
+    // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
@@ -84,10 +84,11 @@ int main(int, char**)
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoTaskBarIcons;
     //io.ConfigFlags |= ImGuiConfigFlags_ViewportsNoMerge;
 
+    // Setup Platform/Renderer bindings
     ImGui_ImplWin32_Init(hwnd);
     ImGui_ImplDX9_Init(g_pd3dDevice);
 
-    // Setup style
+    // Setup Style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 

examples/imgui_impl_glfw.cpp

@@ -16,6 +16,7 @@
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2018-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2018-11-07: Inputs: When installing our GLFW callbacks, we save user's previously installed ones - if any - and chain call them.
 //  2018-08-01: Inputs: Workaround for Emscripten which doesn't seem to handle focus related calls.
 //  2018-06-29: Inputs: Added support for the ImGuiMouseCursor_Hand cursor.
 //  2018-06-08: Misc: Extracted imgui_impl_glfw.cpp/.h away from the old combined GLFW+OpenGL/Vulkan examples.
@@ -54,12 +55,18 @@ enum GlfwClientApi
     GlfwClientApi_OpenGL,
     GlfwClientApi_Vulkan
 };
-static GLFWwindow*      g_Window = NULL;
-static GlfwClientApi    g_ClientApi = GlfwClientApi_Unknown;
-static double           g_Time = 0.0;
-static bool             g_MouseJustPressed[5] = { false, false, false, false, false };
-static GLFWcursor*      g_MouseCursors[ImGuiMouseCursor_COUNT] = { 0 };
-static bool             g_WantUpdateMonitors = true;
+static GLFWwindow*          g_Window = NULL;    // Main window
+static GlfwClientApi        g_ClientApi = GlfwClientApi_Unknown;
+static double               g_Time = 0.0;
+static bool                 g_MouseJustPressed[5] = { false, false, false, false, false };
+static GLFWcursor*          g_MouseCursors[ImGuiMouseCursor_COUNT] = { 0 };
+static bool                 g_WantUpdateMonitors = true;
+
+// Chain GLFW callbacks for main viewport: our callbacks will call the user's previously installed callbacks, if any.
+static GLFWmousebuttonfun   g_PrevUserCallbackMousebutton = NULL;
+static GLFWscrollfun        g_PrevUserCallbackScroll = NULL;
+static GLFWkeyfun           g_PrevUserCallbackKey = NULL;
+static GLFWcharfun          g_PrevUserCallbackChar = NULL;
 
 // Forward Declarations
 static void ImGui_ImplGlfw_InitPlatformInterface();
@@ -76,49 +83,53 @@ static void ImGui_ImplGlfw_SetClipboardText(void* user_data, const char* text)
     glfwSetClipboardString((GLFWwindow*)user_data, text);
 }
 
-void ImGui_ImplGlfw_MouseButtonCallback(GLFWwindow*, int button, int action, int /*mods*/)
+void ImGui_ImplGlfw_MouseButtonCallback(GLFWwindow* window, int button, int action, int mods)
 {
+    if (g_PrevUserCallbackMousebutton != NULL && window == g_Window)
+        g_PrevUserCallbackMousebutton(window, button, action, mods);
+
     if (action == GLFW_PRESS && button >= 0 && button < IM_ARRAYSIZE(g_MouseJustPressed))
         g_MouseJustPressed[button] = true;
 }
 
-void ImGui_ImplGlfw_ScrollCallback(GLFWwindow*, double xoffset, double yoffset)
+void ImGui_ImplGlfw_ScrollCallback(GLFWwindow* window, double xoffset, double yoffset)
 {
+    if (g_PrevUserCallbackScroll != NULL && window == g_Window)
+        g_PrevUserCallbackScroll(window, xoffset, yoffset);
+
     ImGuiIO& io = ImGui::GetIO();
     io.MouseWheelH += (float)xoffset;
     io.MouseWheel += (float)yoffset;
 }
 
-void ImGui_ImplGlfw_KeyCallback(GLFWwindow*, int key, int, int action, int mods)
+void ImGui_ImplGlfw_KeyCallback(GLFWwindow* window, int key, int scancode, int action, int mods)
 {
+    if (g_PrevUserCallbackKey != NULL && window == g_Window)
+        g_PrevUserCallbackKey(window, key, scancode, action, mods);
+
     ImGuiIO& io = ImGui::GetIO();
     if (action == GLFW_PRESS)
         io.KeysDown[key] = true;
     if (action == GLFW_RELEASE)
         io.KeysDown[key] = false;
 
-    (void)mods; // Modifiers are not reliable across systems
+    // Modifiers are not reliable across systems
     io.KeyCtrl = io.KeysDown[GLFW_KEY_LEFT_CONTROL] || io.KeysDown[GLFW_KEY_RIGHT_CONTROL];
     io.KeyShift = io.KeysDown[GLFW_KEY_LEFT_SHIFT] || io.KeysDown[GLFW_KEY_RIGHT_SHIFT];
     io.KeyAlt = io.KeysDown[GLFW_KEY_LEFT_ALT] || io.KeysDown[GLFW_KEY_RIGHT_ALT];
     io.KeySuper = io.KeysDown[GLFW_KEY_LEFT_SUPER] || io.KeysDown[GLFW_KEY_RIGHT_SUPER];
 }
 
-void ImGui_ImplGlfw_CharCallback(GLFWwindow*, unsigned int c)
+void ImGui_ImplGlfw_CharCallback(GLFWwindow* window, unsigned int c)
 {
+    if (g_PrevUserCallbackChar != NULL && window == g_Window)
+        g_PrevUserCallbackChar(window, c);
+
     ImGuiIO& io = ImGui::GetIO();
     if (c > 0 && c < 0x10000)
         io.AddInputCharacter((unsigned short)c);
 }
 
-void ImGui_ImplGlfw_InstallCallbacks(GLFWwindow* window)
-{
-    glfwSetMouseButtonCallback(window, ImGui_ImplGlfw_MouseButtonCallback);
-    glfwSetScrollCallback(window, ImGui_ImplGlfw_ScrollCallback);
-    glfwSetKeyCallback(window, ImGui_ImplGlfw_KeyCallback);
-    glfwSetCharCallback(window, ImGui_ImplGlfw_CharCallback);
-}
-
 static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, GlfwClientApi client_api)
 {
     g_Window = window;
@@ -169,8 +180,18 @@ static bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks, Glfw
     g_MouseCursors[ImGuiMouseCursor_ResizeNWSE] = glfwCreateStandardCursor(GLFW_ARROW_CURSOR);  // FIXME: GLFW doesn't have this.
     g_MouseCursors[ImGuiMouseCursor_Hand] = glfwCreateStandardCursor(GLFW_HAND_CURSOR);
     
+    // Chain GLFW callbacks: our callbacks will call the user's previously installed callbacks, if any.
+    g_PrevUserCallbackMousebutton = NULL;
+    g_PrevUserCallbackScroll = NULL;
+    g_PrevUserCallbackKey = NULL;
+    g_PrevUserCallbackChar = NULL;
     if (install_callbacks)
-        ImGui_ImplGlfw_InstallCallbacks(window);
+    {
+        g_PrevUserCallbackMousebutton = glfwSetMouseButtonCallback(window, ImGui_ImplGlfw_MouseButtonCallback);
+        g_PrevUserCallbackScroll = glfwSetScrollCallback(window, ImGui_ImplGlfw_ScrollCallback);
+        g_PrevUserCallbackKey = glfwSetKeyCallback(window, ImGui_ImplGlfw_KeyCallback);
+        g_PrevUserCallbackChar = glfwSetCharCallback(window, ImGui_ImplGlfw_CharCallback);
+    }
 
     // Our mouse update function expect PlatformHandle to be filled for the main viewport
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
@@ -388,7 +409,12 @@ static void ImGui_ImplGlfw_CreateWindow(ImGuiViewport* viewport)
     data->Window = glfwCreateWindow((int)viewport->Size.x, (int)viewport->Size.y, "No Title Yet", NULL, share_window);
     data->WindowOwned = true;
     viewport->PlatformHandle = (void*)data->Window;
-    ImGui_ImplGlfw_InstallCallbacks(data->Window);
+
+    // Install callbacks for secondary viewports
+    glfwSetMouseButtonCallback(data->Window, ImGui_ImplGlfw_MouseButtonCallback);
+    glfwSetScrollCallback(data->Window, ImGui_ImplGlfw_ScrollCallback);
+    glfwSetKeyCallback(data->Window, ImGui_ImplGlfw_KeyCallback);
+    glfwSetCharCallback(data->Window, ImGui_ImplGlfw_CharCallback);
     glfwSetWindowCloseCallback(data->Window, ImGui_ImplGlfw_WindowCloseCallback);
     glfwSetWindowPosCallback(data->Window, ImGui_ImplGlfw_WindowPosCallback);
     glfwSetWindowSizeCallback(data->Window, ImGui_ImplGlfw_WindowSizeCallback);

examples/imgui_impl_glfw.h

@@ -26,9 +26,8 @@ IMGUI_IMPL_API bool     ImGui_ImplGlfw_InitForVulkan(GLFWwindow* window, bool in
 IMGUI_IMPL_API void     ImGui_ImplGlfw_Shutdown();
 IMGUI_IMPL_API void     ImGui_ImplGlfw_NewFrame();
 
-// GLFW callbacks (installed by default if you enable 'install_callbacks' during initialization)
-// Provided here if you want to chain callbacks.
-// You can also handle inputs yourself and use those as a reference.
+// InitXXX function with 'install_callbacks=true': install GLFW callbacks. They will call user's previously installed callbacks, if any.
+// InitXXX function with 'install_callbacks=false': do not install GLFW callbacks. You will need to call them yourself from your own GLFW callbacks.
 IMGUI_IMPL_API void     ImGui_ImplGlfw_MouseButtonCallback(GLFWwindow* window, int button, int action, int mods);
 IMGUI_IMPL_API void     ImGui_ImplGlfw_ScrollCallback(GLFWwindow* window, double xoffset, double yoffset);
 IMGUI_IMPL_API void     ImGui_ImplGlfw_KeyCallback(GLFWwindow* window, int key, int scancode, int action, int mods);