(Still need help) Program menubar like the custom engine picture on dear imgui github

#1

Hi, I’m just getting started with Dear ImGui.
I’m trying to make something very simple, which is a 2D map editor where you can create, open, edit and save map. However since I am just getting started, I’m only looking to create a menu bar like this https://cloud.githubusercontent.com/assets/8225057/20628927/33e14cac-b329-11e6-80f6-9524e93b048a.png for now.
As you see that program has a menu bar at the very top, not attached to any of the widgets/windows.
How will I achieve this? :stuck_out_tongue:
Any help is much appreciated, thank you.

edit: I of course have to clarify that I am using Allegro 5, if it is of any concern.

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#2

Here’s a quick example hope it helps, I would recommend checking imgui_demo.cpp too.

if(ImGui::BeginMainMenuBar())
{
  if (ImGui::BeginMenu("File"))
  {
     if(ImGui::MenuItem("New"))
     {
        //Do something
     }
     ImGui::EndMenu();
   }

   ImGui::EndMainMenuBar();
}

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#3

Hi, thanks for the sample code, however when I enter it into the programs loop and debug, it crashes with abort() error code: Assertion failed: g.FrameScopeActive, file c:\users\matias\source\repos\map editor\map editor\imgui.cpp, line 4918

bool running = true;
    while (running)
    {

		if (ImGui::BeginMainMenuBar())
		{
			if (ImGui::BeginMenu("File"))
			{
				if (ImGui::MenuItem("New"))
				{
					//Do something
				}
				ImGui::EndMenu();
			}

			ImGui::EndMainMenuBar();
		}


        // Poll and handle events (inputs, window resize, etc.)
        // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
        // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application.
        // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.
        // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
        ALLEGRO_EVENT ev;
        while (al_get_next_event(queue, &ev))
        {
            ImGui_ImplAllegro5_ProcessEvent(&ev);
            if (ev.type == ALLEGRO_EVENT_DISPLAY_CLOSE)
                running = false;
            if (ev.type == ALLEGRO_EVENT_DISPLAY_RESIZE)
            {
                ImGui_ImplAllegro5_InvalidateDeviceObjects();
                al_acknowledge_resize(display);
                ImGui_ImplAllegro5_CreateDeviceObjects();
            }
        }

        // Start the Dear ImGui frame
        ImGui_ImplAllegro5_NewFrame();
        ImGui::NewFrame();

        // 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
        if (show_demo_window)
            ImGui::ShowDemoWindow(&show_demo_window);

        // 2. Show a simple window that we create ourselves. We use a Begin/End pair to created a named window.
        {
            static float f = 0.0f;
            static int counter = 0;

			ImGui::Begin("Configuration");                          // Create a window called "Hello, world!" and append into it.

            ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
            ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
            ImGui::Checkbox("Map Editor", &show_mapeditor_window);	// Map editor window

            ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
            ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color

            if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
                counter++;
            ImGui::SameLine();
            ImGui::Text("counter = %d", counter);

            ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate);
            ImGui::End();
        }

        // 3. Show another simple window.
        if (show_mapeditor_window)
        {
            ImGui::Begin("Another Window", &show_mapeditor_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
            ImGui::Text("Hello from another window!");
            if (ImGui::Button("Close Me"))
                show_mapeditor_window = false;
            ImGui::End();
        }

        // Rendering
        ImGui::Render();
        al_clear_to_color(al_map_rgba_f(clear_color.x, clear_color.y, clear_color.z, clear_color.w));
        ImGui_ImplAllegro5_RenderDrawData(ImGui::GetDrawData());
        al_flip_display();
    }
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#4

Read the comment on the line of your assert you will understand what you have done wrong.

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