Popup Modal window initial size ?

[DaveInDev]

Version: Dear ImGui 1.77 WIP (17601)
Branch: master
Back-ends: SFML
Compiler: VS2019 c++
Operating System: win10x64

Hi Omar,

I really have problem with sizing objects...

Here is the code of a little confirmation popup (a window with a variable title and yes/no buttons that returns 0 if nothing if clicked, 1 if no, 2 if yes)

The problem is that the popup width is sized to the 2 buttons, not to the title bar. Is there a way to autosize this correctly at first appearing (the title can have variable length) ?

	Uint8 Confirm(const std::string& title)
	{
		static bool showWindow = false;
		Uint8 ret = 0;
		std::string s = title + "###confirm";

		if (!showWindow)
		{
			ImGui::OpenPopup(s.c_str());
			showWindow = true;
		}

		if (ImGui::BeginPopupModal(s.c_str(),nullptr))
		{
			if (ImGui::Button("Yes"))
			{
				showWindow = false;
				ImGui::CloseCurrentPopup();
				ret = 2;
			}

			ImGui::SameLine();

			if (ImGui::Button("No"))
			{
				showWindow = false;
				ImGui::CloseCurrentPopup();
				ret = 1;
			}
			ImGui::EndPopup();
		}

		return(ret);
	}

[ocornut]

Hello,

It's been always the case that title bar width doesn't contribute to width calculation.
(e.g. #176 (comment))

I don't imagine we should allocate a window flag for that, we could decide it would be a global style flag however it would be ambiguous and misleading when switching single windows to be using tabs in the docking branch, so I'm not sure this is a good idea right now.

You can enforce a minimum automatic width for the window by using, e.g.

ImGui::Begin(...)
ImGui::SetCursorPosX(some_width)
ImGui::SetCursorPosX(0.0f)
[...]

That will feed into the auto calculated width.
some_width may be CalcTextSize(title).x + GetFrameHeight() * number_of_visible button.

Not suggesting this is a great solution but it might be good enough in your case?

[DaveInDev]

Hi Omar,
Thanks for your answer.
I do not understand why a global flag would not be desirable : I still do not find very "nice" that a simple window opens with its title truncated... But you know the code repercussions better than me ;-)
Anyway, thanks for the trick, it does the job !