How to correctly use IDs ? #719

victorlevasseur · 2016-06-29T09:24:48Z

Hi,

Here is my code :

ImGui::SetNextWindowPosCenter();
    ImGui::SetNextWindowSize(ImVec2(350, 200));
    ImGui::Begin("YAPG - Main menu");
        //Level selection
        static char levelName[512] = "level.xml";
        ImGui::InputText("", levelName, 512);
        ImGui::SameLine();
        if(ImGui::Button("Play !"))
        {
            getStateEngine().pauseAndStartState
                <level::LevelState, std::string, resources::AllResourcesManagers&, settings::SettingsManager&, sfg::SFGUI&, sfg::Desktop&>(
                std::string(levelName), m_resourcesManager, m_settingsManager, m_sfgui, m_desktop
            );
        }

        //Level editor
        if(ImGui::Button("Level editor"))
        {
            getStateEngine().pauseAndStartState
                <editor::LevelEditorState, resources::AllResourcesManagers&, settings::SettingsManager&, sfg::SFGUI&, sfg::Desktop&>(
                m_resourcesManager, m_settingsManager, m_sfgui, m_desktop
            );
        }

        //Settings
        if(ImGui::Button("Settings..."))
        {
            ImGui::OpenPopup("Settings");
        }

        //Settings popup
        ImGui::SetNextWindowSize(ImVec2(350, 400));
        if(ImGui::BeginPopupModal("Settings"))
        {
            if(ImGui::CollapsingHeader("Keyboard settings"))
            {
                ImGui::Indent();
                for(std::size_t i = 0; i < 4; ++i)
                {
                    std::string label = "Player " + std::to_string(i + 1);
                    if(ImGui::CollapsingHeader(label.data()))
                    {
                        ImGui::Text("Left key: ");
                        ImGui::SameLine();
                        if(ImGui::Button(m_playersKeys[i][0]))
                        {
                            m_selectedKeyButton = m_playersKeys[i][0];
                        }

                        ImGui::Text("Right key: ");
                        ImGui::SameLine();
                        if(ImGui::Button(m_playersKeys[i][1]))
                        {
                            m_selectedKeyButton = m_playersKeys[i][1];
                        }

                        ImGui::Text("Jump key: ");
                        ImGui::SameLine();
                        if(ImGui::Button(m_playersKeys[i][2]))
                        {
                            m_selectedKeyButton = m_playersKeys[i][2];
                        }
                    }
                }
                ImGui::Unindent();
            }

            if(ImGui::Button("Close"))
            {
                ImGui::CloseCurrentPopup();
            }
            ImGui::EndPopup();
        }

        //About
        if(ImGui::Button("About..."))
        {

        }

        //Quit button
        if(ImGui::Button("Exit"))
        {
            getStateEngine().stopStateAndUnpause();
        }
    ImGui::End();

As you can see, I have a "for" loop, so I probably need to use PushID and PopID. However, I don't know where to put them. I tried all the possible combinations but it always resulted in buttons randomly acting like others (for exemple : the jump key button of the third player launch the level editor as the "Editor" button only should do !).

So, how do the IDs work ?

ocornut · 2016-06-29T09:30:10Z

Have you read the FAQ?
What have you tried with PushID/PopID ?

ratchetfreak · 2016-06-29T09:33:43Z

In the faq in imgui.cpp quite literally says what you should do:

for (int i = 0; i < 100; i++)
{
     PushID(i);

     //...

     PopID();
}

victorlevasseur · 2016-06-29T09:34:06Z

Obviously yes. Like I said, I tried all the possible combinations. For instance :

ImGui::SetNextWindowPosCenter();
    ImGui::SetNextWindowSize(ImVec2(350, 200));
    ImGui::Begin("YAPG - Main menu");
        //Level selection
        static char levelName[512] = "level.xml";
        ImGui::InputText("", levelName, 512);
        ImGui::SameLine();
        if(ImGui::Button("Play !"))
        {
            getStateEngine().pauseAndStartState
                <level::LevelState, std::string, resources::AllResourcesManagers&, settings::SettingsManager&, sfg::SFGUI&, sfg::Desktop&>(
                std::string(levelName), m_resourcesManager, m_settingsManager, m_sfgui, m_desktop
            );
        }

        //Level editor
        if(ImGui::Button("Level editor"))
        {
            getStateEngine().pauseAndStartState
                <editor::LevelEditorState, resources::AllResourcesManagers&, settings::SettingsManager&, sfg::SFGUI&, sfg::Desktop&>(
                m_resourcesManager, m_settingsManager, m_sfgui, m_desktop
            );
        }

        //Settings
        if(ImGui::Button("Settings..."))
        {
            ImGui::OpenPopup("Settings");
        }

        //Settings popup
        ImGui::SetNextWindowSize(ImVec2(350, 400));
        if(ImGui::BeginPopupModal("Settings"))
        {
            ImGui::PushID("keyboard_settings"); //Just to be sure !
            if(ImGui::CollapsingHeader("Keyboard settings"))
            {
                ImGui::Indent();
                for(std::size_t i = 0; i < 4; ++i)
                {
                    std::string label = "Player " + std::to_string(i + 1);
                    ImGui::PushID(i);
                    if(ImGui::CollapsingHeader(label.data()))
                    {
                        ImGui::Text("Left key: ");
                        ImGui::SameLine();
                        if(ImGui::Button(m_playersKeys[i][0]))
                        {
                            m_selectedKeyButton = m_playersKeys[i][0];
                        }

                        ImGui::Text("Right key: ");
                        ImGui::SameLine();
                        if(ImGui::Button(m_playersKeys[i][1]))
                        {
                            m_selectedKeyButton = m_playersKeys[i][1];
                        }

                        ImGui::Text("Jump key: ");
                        ImGui::SameLine();
                        if(ImGui::Button(m_playersKeys[i][2]))
                        {
                            m_selectedKeyButton = m_playersKeys[i][2];
                        }
                    }
                    ImGui::PopID();
                }
                ImGui::Unindent();
            }

            if(ImGui::Button("Close"))
            {
                ImGui::CloseCurrentPopup();
            }
            ImGui::PopID();
            ImGui::EndPopup();
        }

        //About
        if(ImGui::Button("About..."))
        {

        }

        //Quit button
        if(ImGui::Button("Exit"))
        {
            getStateEngine().stopStateAndUnpause();
        }
    ImGui::End();

Still give random bad click actions. :(

ocornut · 2016-06-29T09:35:41Z

This should work, I can't see why it wouldn't. You are perhaps doing something else wrong in the code.
Perhaps try to reduce the code into a mini-repro that I can use here first.

(Never tell yourself "I tried all the possible combinations." it is most often a wrong statement.)

victorlevasseur · 2016-06-29T09:37:25Z

Ok, at least I use them correctly :). I'll take another look at my code. ;)

(Great lib by the way 👍 )

ocornut · 2016-06-29T09:40:44Z

Maybe you are handling m_selectedKeyButton in your code. Add printf or log output in the Button() scopes if you want to make sure they aren't called twice.

ratchetfreak · 2016-06-29T09:47:34Z

Do you change the contents of m_playersKeys? If so I would suggest using a "###id" postfix to make sure that's not the issue:

            char[128] labelBuffer;
            for(std::size_t i = 0; i < 4; ++i)
            {
                std::string label = "Player " + std::to_string(i + 1);
                ImGui::PushID(i);
                if(ImGui::CollapsingHeader(label.data()))
                {
                    ImGui::Text("Left key: ");
                    ImGui::SameLine();
                    sprintf(labelBuffer, "%s###left", m_playersKeys[i][0]);
                    if(ImGui::Button(labelBuffer))
                    {
                        m_selectedKeyButton = m_playersKeys[i][0];
                    }

                    ImGui::Text("Right key: ");
                    ImGui::SameLine();
                    sprintf(labelBuffer, "%s###right", m_playersKeys[i][1]);
                    if(ImGui::Button(labelBuffer))
                    {
                        m_selectedKeyButton = m_playersKeys[i][1];
                    }

                    ImGui::Text("Jump key: ");
                    ImGui::SameLine();
                    sprintf(labelBuffer, "%s###jump", m_playersKeys[i][2]);
                    if(ImGui::Button(labelBuffer))
                    {
                        m_selectedKeyButton = m_playersKeys[i][2];
                    }
                }
                ImGui::PopID();
            }

ocornut · 2016-06-29T12:22:49Z

Good point (and hence why posting a screenshot of the context is always helpful).
If your playersKey contains the same string it'll conflict.
You can fix it as pointed above or by using PushId/PopId.

Typically your code could you loop over an array of keys to set,

const char* keys_names[] = { "Left", "Right", "Jump");
for (int key_i = 0; key_i < ARRAYSIZE(keys_names); key_i++)
{
   ImGui::PushID(n);
   ImGuI::Text("%s key: ", keys_names[key_i]);
   ImGui::SameLine();
   if (ImGui::Button(m_playersKeys[i][key_i])
   {
      ...
   }
   ImGui::PopID();
}

victorlevasseur · 2016-07-01T07:15:57Z

Thanks for your help, it works now :)

tankorsmash · 2019-10-16T05:14:50Z

imgui/imgui.cpp

Line 637 in 9d6b2b0

Q: Why are multiple widgets reacting when I interact with a single one?

Here's an updated link to that FAQ question with all the info about PushID/PopID

Also #74, #96, #480, #501, #647, #654, #719, #843, #894, #1057, #1173, #1390, #1414, #1556, #1768, #2041, #2116, #2330, #2475, #2562, #2667, #2807, #2885, #3102, #3375, #3526, #3964, #4008, #4070, #4158, #4172, #4199, #4375, #4395, #4471, #4548, #4612, #4631, #4657, #4796, #5210, #5303, #5360, #5393, #5533, #5692, #5707, #5729, #5773, #5787, #5884, #6046, #6093, #6186, #6223, #6364, #6387, #6567, #6692, #6724, #6939, #6984, #7246, #7270, #7375, #7421, #7434, #7472, #7581, #7724, #7926, #7937 and probably more.. Tagging to increase visibility!

ocornut closed this as completed Jul 1, 2016

ocornut added the label/id and id stack implicit identifiers, pushid(), id stack label Apr 6, 2020

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How to correctly use IDs ? #719

How to correctly use IDs ? #719

victorlevasseur commented Jun 29, 2016 •

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ocornut commented Jun 29, 2016

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victorlevasseur commented Jun 29, 2016

ocornut commented Jun 29, 2016 •

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victorlevasseur commented Jun 29, 2016

ocornut commented Jun 29, 2016

ratchetfreak commented Jun 29, 2016

ocornut commented Jun 29, 2016

victorlevasseur commented Jul 1, 2016

tankorsmash commented Oct 16, 2019

How to correctly use IDs ? #719

How to correctly use IDs ? #719

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victorlevasseur commented Jun 29, 2016 • edited Loading

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