Viewport: Coupling non-main viewport to one window. Viewport name derived from the window. Added ImGuiConfigFlags_PlatformNoTaskBar, off by default (aka re-established task-bars by default for now). (#1542)

examples/directx10_example/main.cpp

@@ -116,6 +116,7 @@ int main(int, char**)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_EnableViewports;
+    io.ConfigFlags |= ImGuiConfigFlags_PlatformNoTaskBar;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
 
     ImGui_ImplWin32_Init(hwnd);

examples/directx11_example/main.cpp

@@ -139,6 +139,7 @@ int main(int, char**)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_EnableViewports;
+    io.ConfigFlags |= ImGuiConfigFlags_PlatformNoTaskBar;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
 
     ImGui_ImplWin32_Init(hwnd);

examples/imgui_impl_glfw.cpp

@@ -317,7 +317,6 @@ static void ImGui_ImplGlfw_CreateViewport(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;
-    viewport->Name = NULL;
     ImGui_ImplGlfw_InstallCallbacks(data->Window);
 }
 
@@ -358,7 +357,8 @@ static void ImGui_ImplGlfw_ShowWindow(ImGuiViewport* viewport)
 #if defined(_WIN32)
     // GLFW hack: Hide icon from task bar
     HWND hwnd = glfwGetWin32Window(data->Window);
-    if (viewport->Flags & ImGuiViewportFlags_NoDecoration)
+    ImGuiIO& io = ImGui::GetIO();
+    if (io.ConfigFlags & ImGuiConfigFlags_PlatformNoTaskBar)
     {
         LONG ex_style = ::GetWindowLong(hwnd, GWL_EXSTYLE);
         ex_style &= ~WS_EX_APPWINDOW;

examples/imgui_impl_sdl2.cpp

@@ -316,7 +316,8 @@ static void ImGui_ImplSDL2_ShowWindow(ImGuiViewport* viewport)
 
         // SDL hack: Hide icon from task bar
         // Note: SDL 2.0.6+ has a SDL_WINDOW_SKIP_TASKBAR flag which is supported under Windows but the way it create the window breaks our seamless transition.
-        if (viewport->Flags & ImGuiViewportFlags_NoDecoration)
+        ImGuiIO& io = ImGui::GetIO();
+        if (io.ConfigFlags & ImGuiConfigFlags_PlatformNoTaskBar)
         {
             LONG ex_style = ::GetWindowLong(hwnd, GWL_EXSTYLE);
             ex_style &= ~WS_EX_APPWINDOW;

examples/imgui_impl_win32.cpp

@@ -291,15 +291,18 @@ static void ImGui_ImplWin32_CreateViewport(ImGuiViewport* viewport)
     ImGuiPlatformDataWin32* data = IM_NEW(ImGuiPlatformDataWin32)();
     viewport->PlatformUserData = data;
 
-    if (viewport->Flags & ImGuiViewportFlags_NoDecoration)
+    ImGuiIO& io = ImGui::GetIO();
+    bool no_decoration = (viewport->Flags & ImGuiViewportFlags_NoDecoration) != 0;
+    bool no_task_bar = (io.ConfigFlags & ImGuiConfigFlags_PlatformNoTaskBar) != 0;
+    if (no_decoration)
     {
         data->DwStyle = WS_POPUP;
-        data->DwExStyle = 0;
+        data->DwExStyle = no_task_bar ? WS_EX_TOOLWINDOW : WS_EX_APPWINDOW;
     }
     else
     {
         data->DwStyle = WS_OVERLAPPEDWINDOW;
-        data->DwExStyle = WS_EX_TOOLWINDOW;
+        data->DwExStyle = no_task_bar ? WS_EX_TOOLWINDOW : WS_EX_APPWINDOW;
     }
 
     // Create window

examples/opengl3_example/main.cpp

@@ -36,6 +36,7 @@ int main(int, char**)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_EnableViewports;
+    io.ConfigFlags |= ImGuiConfigFlags_PlatformNoTaskBar;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;   // Enable Gamepad Controls
 

examples/sdl_opengl3_example/main.cpp

@@ -38,6 +38,7 @@ int main(int, char**)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_EnableViewports;
+    io.ConfigFlags |= ImGuiConfigFlags_PlatformNoTaskBar;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
 
     ImGui_ImplSDL2_Init(window, gl_context);

examples/sdl_vulkan_example/main.cpp

@@ -345,6 +345,7 @@ int main(int, char**)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_EnableViewports;
+    io.ConfigFlags |= ImGuiConfigFlags_PlatformNoTaskBar;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
 
     ImGui_ImplVulkan_InitInfo init_info = {};

examples/vulkan_example/main.cpp

@@ -354,6 +354,7 @@ int main(int, char**)
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_EnableViewports;
+    io.ConfigFlags |= ImGuiConfigFlags_PlatformNoTaskBar;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
 
     ImGui_ImplVulkan_InitInfo init_info = {};

imgui.cpp

@@ -3269,7 +3269,7 @@ static void ImGui::UpdateMovingWindowDropViewport(ImGuiWindow* window)
     {
         // Create new viewport
         ImVec2 os_pos = ConvertViewportPosToOsDesktopPos(window->Pos, window->Viewport);
-        ImGuiViewport* viewport = Viewport(window->ID, 0, os_pos, window->Size);
+        ImGuiViewport* viewport = Viewport(window, window->ID, 0, os_pos, window->Size);
         SetWindowViewportTranslateToPreservePlatformPos(window, window->Viewport, viewport);
     }
 }
@@ -3388,7 +3388,7 @@ static void ImGui::UpdateViewports()
     ImVec2 main_viewport_os_desktop_pos = ImVec2(0.0f, 0.0f);
     if ((g.IO.ConfigFlags & ImGuiConfigFlags_EnableViewports))
         main_viewport_os_desktop_pos = g.IO.PlatformInterface.GetWindowPos(main_viewport);
-    Viewport(IMGUI_VIEWPORT_DEFAULT_ID, ImGuiViewportFlags_MainViewport | ImGuiViewportFlags_HostOtherWindows, main_viewport_os_desktop_pos, g.IO.DisplaySize);
+    Viewport(NULL, IMGUI_VIEWPORT_DEFAULT_ID, ImGuiViewportFlags_MainViewport | ImGuiViewportFlags_HostOtherWindows, main_viewport_os_desktop_pos, g.IO.DisplaySize);
 
     if (!(g.IO.ConfigFlags & ImGuiConfigFlags_EnableViewports))
     {
@@ -3454,6 +3454,7 @@ static void UpdatePlatformWindows()
         ImGuiViewport* viewport = g.Viewports[i];
         if ((viewport->Flags & ImGuiViewportFlags_MainViewport) || (viewport->LastFrameActive < g.FrameCount))
             continue;
+        IM_ASSERT(viewport->Window != NULL);
         viewport->PlatformRequestClose = false;
 
         // FIXME-PLATFORM
@@ -3466,13 +3467,17 @@ static void UpdatePlatformWindows()
         g.IO.PlatformInterface.SetWindowPos(viewport, viewport->PlatformOsDesktopPos);
         g.IO.PlatformInterface.SetWindowSize(viewport, viewport->Size);
 
-        char name[20];
-        sprintf(name, "Viewport_%08X", viewport->ID);
-        if (viewport->Name == NULL || strcmp(viewport->Name, name) != 0)
+        // Update title bar
+        const char* title_begin = viewport->Window->Name;
+        const char* title_end = ImGui::FindRenderedTextEnd(title_begin);
+        const ImGuiID title_hash = ImHash(title_begin, (int)(title_end - title_begin));
+        if (viewport->LastNameHash != title_hash )
         {
-            g.IO.PlatformInterface.SetWindowTitle(viewport, name);
-            ImGui::MemFree(viewport->Name);
-            viewport->Name = ImStrdup(name);
+            viewport->LastNameHash = title_hash;
+            char* title_displayed = ImStrdup(viewport->Window->Name);
+            title_displayed[title_end - title_begin] = 0;
+            g.IO.PlatformInterface.SetWindowTitle(viewport, title_displayed);
+            ImGui::MemFree(title_displayed);
         }
 
         if (is_new_window)
@@ -4512,7 +4517,7 @@ void ImGui::SetCurrentViewport(ImGuiViewport* viewport)
         g.IO.PlatformInterface.BeginViewport(g.CurrentViewport);
 }
 
-ImGuiViewport* ImGui::Viewport(ImGuiID id, ImGuiViewportFlags flags, const ImVec2& os_desktop_pos, const ImVec2& size)
+ImGuiViewport* ImGui::Viewport(ImGuiWindow* window, ImGuiID id, ImGuiViewportFlags flags, const ImVec2& os_desktop_pos, const ImVec2& size)
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(id != 0);
@@ -4532,6 +4537,7 @@ ImGuiViewport* ImGui::Viewport(ImGuiID id, ImGuiViewportFlags flags, const ImVec
     }
 
     IM_ASSERT(viewport->Pos.y == 0.0f);
+    viewport->Window = window;
     viewport->Flags = flags;
     viewport->PlatformOsDesktopPos = os_desktop_pos;
     viewport->LastFrameActive = g.FrameCount;
@@ -5940,8 +5946,8 @@ static void ImGui::UpdateWindowViewport(ImGuiWindow* window, bool window_pos_set
         {
             // Create an undecorated, temporary OS/platform window
             ImVec2 os_desktop_pos = ConvertViewportPosToOsDesktopPos(g.IO.MousePos - g.ActiveIdClickOffset, g.MouseViewport);
-            ImGuiViewportFlags viewport_flags =  ImGuiViewportFlags_NoDecoration | ImGuiViewportFlags_NoFocusOnAppearing | ImGuiViewportFlags_NoInputs;
-            ImGuiViewport* viewport = Viewport(window->ID, viewport_flags, os_desktop_pos, window->Size);
+            ImGuiViewportFlags viewport_flags = ImGuiViewportFlags_NoDecoration | ImGuiViewportFlags_NoFocusOnAppearing | ImGuiViewportFlags_NoInputs;
+            ImGuiViewport* viewport = Viewport(window, window->ID, viewport_flags, os_desktop_pos, window->Size);
             window->Flags |= ImGuiWindowFlags_FullViewport | ImGuiWindowFlags_NoBringToFrontOnFocus;
             window->Viewport = viewport;
             created_viewport = true;
@@ -5980,7 +5986,7 @@ static void ImGui::UpdateWindowViewport(ImGuiWindow* window, bool window_pos_set
         {
             if (window->ViewportOsDesktopPos.x != FLT_MAX && window->ViewportOsDesktopPos.y != FLT_MAX)
             {
-                ImGuiViewport* viewport = Viewport(window->ID, ImGuiViewportFlags_NoDecoration, window->ViewportOsDesktopPos, window->Size);
+                ImGuiViewport* viewport = Viewport(window, window->ID, ImGuiViewportFlags_NoDecoration, window->ViewportOsDesktopPos, window->Size);
                 window->Flags |= ImGuiWindowFlags_FullViewport | ImGuiWindowFlags_NoBringToFrontOnFocus;
                 window->Viewport = viewport;
                 created_viewport = true;
@@ -6005,6 +6011,10 @@ static void ImGui::UpdateWindowViewport(ImGuiWindow* window, bool window_pos_set
         window->Flags |= ImGuiWindowFlags_FullViewport | ImGuiWindowFlags_NoBringToFrontOnFocus;
     }
 
+    // If the OS window has a title bar, hide our imgui title bar
+    if ((window->Flags & ImGuiWindowFlags_FullViewport) && !(window->Viewport->Flags & ImGuiViewportFlags_NoDecoration))
+        window->Flags |= ImGuiWindowFlags_NoTitleBar;
+
     // Disable rounding for the window
     if (window->Viewport != main_viewport)
         window->WindowRounding = 0.0f;
@@ -13933,6 +13943,8 @@ void ImGui::ShowMetricsWindow(bool* p_open)
                 if (ImGui::TreeNode((void*)(intptr_t)viewport->ID, "Viewport #%d, ID: 0x%08X, DrawLists: %d, Size: (%.0f,%.0f)", i, viewport->ID, draw_data->Layers[0].Size, viewport->Size.x, viewport->Size.y))
                 {
                     ImGui::BulletText("Pos: (%.0f,%.0f)", viewport->Pos.x, viewport->Pos.y);
+                    ImGui::BulletText("Flags: 0x%04X", viewport->Flags);
+                    ImGui::BulletText("PlatformOsDesktopPos: (%.0f,%.0f)", viewport->PlatformOsDesktopPos.x, viewport->PlatformOsDesktopPos.y);
                     for (int draw_list_i = 0; draw_list_i < viewport->DrawDataBuilder.Layers[0].Size; draw_list_i++)
                         Funcs::NodeDrawList(NULL, viewport->DrawDataBuilder.Layers[0][draw_list_i], "DrawList");
                     ImGui::TreePop();

imgui.h

@@ -779,16 +779,17 @@ enum ImGuiConfigFlags_
 
     // [BETA] Viewports
     ImGuiConfigFlags_EnableViewports                    = 1 << 4,   // Viewport enable flags (require both ImGuiConfigFlags_PlatformHasViewports + ImGuiConfigFlags_RendererHasViewports set by the respective back-ends)
-    ImGuiConfigFlags_PlatformHasViewports               = 1 << 5,   // Back-end Platform supports multiple viewports
-    ImGuiConfigFlags_PlatformHasMouseHoveredViewport    = 1 << 6,   // Back-end Platform supports setting io.MouseHoveredViewport to the viewport directly under the mouse _IGNORING_ viewports with the ImGuiViewportFlags_NoInputs flag and _REGARDLESS_ of whether another viewport is focused and may be capturing the mouse. This information is _NOT EASY_ to provide correctly with most high-level engines. Don't see this without studying how the examples/ back-end handle it.
-    ImGuiConfigFlags_PlatformHasWantMoveMouseSupport    = 1 << 7,   // Back-end Platform supports io.WantMoveMouse request by updating the OS mouse cursor position (currently only used by ImGuiConfigFlags_NavMoveMouse feature, will be useful for widgets teleporting/wrapping the cursor)
-    ImGuiConfigFlags_PlatformHasWindowAlpha             = 1 << 8,   // Back-end Platform supports transparent windows
-    ImGuiConfigFlags_RendererHasViewports               = 1 << 9,   // Back-end Renderer supports multiple viewports
+    ImGuiConfigFlags_PlatformNoTaskBar                  = 1 << 5,
+    ImGuiConfigFlags_PlatformHasViewports               = 1 << 6,   // Back-end Platform supports multiple viewports
+    ImGuiConfigFlags_PlatformHasMouseHoveredViewport    = 1 << 7,   // Back-end Platform supports setting io.MouseHoveredViewport to the viewport directly under the mouse _IGNORING_ viewports with the ImGuiViewportFlags_NoInputs flag and _REGARDLESS_ of whether another viewport is focused and may be capturing the mouse. This information is _NOT EASY_ to provide correctly with most high-level engines. Don't see this without studying how the examples/ back-end handle it.
+    ImGuiConfigFlags_PlatformHasWantMoveMouseSupport    = 1 << 8,   // Back-end Platform supports io.WantMoveMouse request by updating the OS mouse cursor position (currently only used by ImGuiConfigFlags_NavMoveMouse feature, will be useful for widgets teleporting/wrapping the cursor)
+    ImGuiConfigFlags_PlatformHasWindowAlpha             = 1 << 9,   // Back-end Platform supports transparent windows
+    ImGuiConfigFlags_RendererHasViewports               = 1 << 10,  // Back-end Renderer supports multiple viewports
     
     // Platform Info (free of use, for user/application convenience)
-    ImGuiConfigFlags_IsSRGB                             = 1 << 10,  // Back-end is SRGB-aware (Storage flag to allow your back-end to communicate to shared widgets. Not used by core ImGui)
-    ImGuiConfigFlags_IsTouchScreen                      = 1 << 11,  // Back-end is using a touch screen instead of a mouse (Storage flag to allow your back-end to communicate to shared widgets. Not used by core ImGui)
-    ImGuiConfigFlags_IsOnScreenKeyboard                 = 1 << 12   // Back-end uses an on-screen keyboard when io.WantTextInput is set.
+    ImGuiConfigFlags_IsSRGB                             = 1 << 20,  // Back-end is SRGB-aware (Storage flag to allow your back-end to communicate to shared widgets. Not used by core ImGui)
+    ImGuiConfigFlags_IsTouchScreen                      = 1 << 21,  // Back-end is using a touch screen instead of a mouse (Storage flag to allow your back-end to communicate to shared widgets. Not used by core ImGui)
+    ImGuiConfigFlags_IsOnScreenKeyboard                 = 1 << 22   // Back-end uses an on-screen keyboard when io.WantTextInput is set.
 };
 
 // Enumeration for PushStyleColor() / PopStyleColor()

imgui_internal.h

@@ -530,7 +530,8 @@ struct ImGuiViewport
     ImGuiViewportFlags  Flags;
     int                 LastFrameActive;        
     int                 LastFrameAsRefViewport; // Last frame number this viewport was io.MouseViewportRef
-    char*               Name;                   // Name (OPTIONAL)
+    ImGuiID             LastNameHash;
+    ImGuiWindow*        Window;
     ImVec2              Pos;                    // Position in imgui virtual space (Pos.y == 0.0)
     ImVec2              Size;
     ImDrawData          DrawData;
@@ -538,14 +539,15 @@ struct ImGuiViewport
 
     // [Optional] OS/Platform Layer data. This is to allow the creation/manipulate of multiple OS/Platform windows. Not all back-ends will allow this.
     ImVec2              PlatformOsDesktopPos;   // Position in OS desktop/native space
+    float               PlatformDpiScale;       // FIXME-DPI: Unused
     void*               PlatformUserData;       // void* to hold custom data structure for the platform (e.g. windowing info, render context)
     void*               PlatformHandle;         // void* for FindViewportByPlatformHandle(). (e.g. HWND, GlfwWindow*)
     bool                PlatformRequestClose;   // Platform window requested closure
     bool                PlatformRequestResize;  // Platform window requested resize
     void*               RendererUserData;       // void* to hold custom data structure for the renderer (e.g. framebuffer)
 
-    ImGuiViewport(ImGuiID id, int idx)  { ID = id; Idx = idx; Flags = 0; LastFrameActive = LastFrameAsRefViewport = -1; Name = NULL; PlatformUserData = PlatformHandle = NULL; PlatformRequestClose = PlatformRequestResize = false; RendererUserData = NULL; }
-    ~ImGuiViewport()                    { IM_ASSERT(PlatformUserData == NULL && RendererUserData == NULL); if (Name) ImGui::MemFree(Name); }
+    ImGuiViewport(ImGuiID id, int idx)  { ID = id; Idx = idx; Flags = 0; LastFrameActive = LastFrameAsRefViewport = -1; LastNameHash = 0; Window = NULL; PlatformDpiScale = 1.0f; PlatformUserData = PlatformHandle = NULL; PlatformRequestClose = PlatformRequestResize = false; RendererUserData = NULL; }
+    ~ImGuiViewport()                    { IM_ASSERT(PlatformUserData == NULL && RendererUserData == NULL); }
     ImRect  GetRect() const             { return ImRect(Pos.x, Pos.y, Pos.x + Size.x, Pos.y + Size.y); }
     float   GetNextX() const            { const float SPACING = 4.0f; return Pos.x + Size.x + SPACING; }
 };
@@ -1084,7 +1086,7 @@ namespace ImGui
     IMGUI_API void          Shutdown(ImGuiContext* context);    // Since 1.60 this is a _private_ function. You can call DestroyContext() to destroy the context created by CreateContext().
 
     // Viewports
-    IMGUI_API ImGuiViewport*        Viewport(ImGuiID id, ImGuiViewportFlags flags, const ImVec2& os_desktop_pos, const ImVec2& size);   // os_desktop_pos allows imgui to reposition windows relative to each order when moving from one viewport to the other.
+    IMGUI_API ImGuiViewport*        Viewport(ImGuiWindow* window, ImGuiID id, ImGuiViewportFlags flags, const ImVec2& os_desktop_pos, const ImVec2& size);   // os_desktop_pos allows imgui to reposition windows relative to each order when moving from one viewport to the other.
     inline ImVector<ImGuiViewport*>&GetViewports() { return GImGui->Viewports; }
     inline ImGuiViewport*           GetMainViewport() { return GImGui->Viewports[0]; }
     IMGUI_API ImGuiViewport*        FindViewportByID(ImGuiID id);