No way i can render popup modal

[fuhranku]

Greetings. I'm working with OpenGl 3.30 w/ C++

Version/Branch of Dear ImGui:

Version: 1.74
Branch: master

My Issue/Question:

Modal is not showing under any circumstances. I've read issue #331 and working examples here exposed are not working for me either. A simple case like this won't show anything at all

I initialize ImGui like this:`

bool UI::init(GLFWwindow* window) {
	IMGUI_CHECKVERSION();
	ImGui::CreateContext();
	if (!ImGui_ImplGlfw_InitForOpenGL(window, true) || !ImGui_ImplOpenGL3_Init("#version 330 core"))
		return false;
	ImGui::StyleColorsDark();
}

My draw function:

void UI::draw() {
	// Start new frame
	ImGui_ImplOpenGL3_NewFrame();
	ImGui_ImplGlfw_NewFrame();
	ImGui::NewFrame();

       // This basic example shows nothing for me
        if (ImGui::BeginMainMenuBar())
        {
            if (ImGui::BeginMenu("menu"))
            {
                if (ImGui::MenuItem("menu item"))
                   ImGui::OpenPopup("popup");
                ImGui::EndMenu();
            }
            ImGui::EndMainMenuBar();
        }

        if (ImGui::BeginPopupModal("popup"))
        {
            ImGui::Text("Lorem ipsum");
            ImGui::EndPopup();
        }

	ImGui::Render();
	ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
}

I've been reading all related issues but apparently it should render my modal with this case, and is not working. Everything else works just fine.

[ocornut]

Hello,

It seems like you missed the key explanation and solution outlined in #331, e.g.
#331 (comment)

You have to remember that OpenPopup() and BeginPopup() are relying on the ID stack:

https://github.com/ocornut/imgui/blob/master/docs/FAQ.md#q-why-are-multiple-widgets-reacting-when-i-interact-with-a-single-one-q-how-can-i-have-multiple-widgets-with-the-same-label-or-with-an-empty-label

So in your example you are doing the Open while the top of ID stack is "mainmenubar" "menu" and you are trying to Begin into it while the top of the ID stack is empty, so the ID don't match.

[fuhranku]

Hello! Thank you for this quick answer! Now i'm trying with boolean flag workaround and it's working now (it seems i did miss key explanation), to be honest ID stack still not 100% clear for me, i'll be diggin more into it.

Thank you, hopping a smooth and fancy workaround for modals :-)

[ocornut]

I'll let you read the linked FAQ, if you still have issue or questions feel free to post here!