Regain focus on canvas after dialog/popup closes

[inflex]

I have a situation where my main canvas/app loses mouse-focus after I open a dialog or menu selection and then close it, requiring me to click the main canvas for it to apply again (only has to be a click-down, the return/up isn't required). I'm using the mouse wheel to zoom in/out on the content and that doesn't work until I first click the mouse somewhere on the main canvas.

The keyboard inputs still work.

Is there something I can do to set the focus back to the canvas after I've done the ImGui::CloseCurrentPopup(); call?

[ocornut]

Hello,
I have just committed 19d02be
Which might fix your issue (unless using the BeginManuMenuBar, see #727)

Let me know if it does, otherwise please post a small repro or just the functions/flags you are using to get to this situation. How are you testing whether you apply the mouse wheel for zooming your canvas?

[inflex]

Here's the part that handles the scroll wheel -> zooming. You'll notice at the bottom that I've put in a debug dump fprintf(stderr,"x"); that just lets me know when the main canvas is focused or not, and that appears to be the crucial aspect - when the x's appear there's no scroll activity, and vice-versa.

This also happens immediately when the program is first loaded.

const ImGuiIO &io = ImGui::GetIO();
if (ImGui::IsWindowFocused()) {

    // Zoom:
    float mwheel = io.MouseWheel;
    if (mwheel != 0.0f) {
        mwheel *= 0.5f;

        // Ctrl slows down the zoom speed:
        if ( ImGui::IsKeyDown(KM(SDL_SCANCODE_LCTRL)) 
|| ImGui::IsKeyDown(KM(SDL_SCANCODE_RCTRL)) ) {
            mwheel *= 0.1f;
        }
        Zoom(io.MousePos.x, io.MousePos.y, mwheel);
    }
} else {
    fprintf(stderr,"x");
}

[ocornut]

Does it still happen with the fix just posted above?

[ocornut]

PS: for
if ( ImGui::IsKeyDown(KM(SDL_SCANCODE_LCTRL)) || ImGui::IsKeyDown(KM(SDL_SCANCODE_RCTRL)) )
You can use
if (io.KeyCtrl) as a convenience.

[inflex]

I'm thinking that maybe I haven't been able to pull the latest from the repo, unfortunately my git-fu is weak; best I can report is this -

WorkstationTT:~/development/OpenBoardView/src/imgui$ git status
HEAD detached at adb85d8

... which makes me think it's not actually using your latest updates ( and when I check the imgui.cpp code it doesn't even come close to matching, so I think I'll go sort that out first. Apologies for wasting your time.

[ocornut]

Git is a mystery to everyone it seems.. Yeah it looks like you are running an old version, and that fix is literally the last commit in the repo that I pushed this morning.

[inflex]

I'll check with a couple of the other participants as a couple of them are more imbued with git-fu than I am. I suspect the detached HEAD option might be something to do with avoiding a moving API target.

I'll report back later as soon as I have an answer. Thankyou.

[inflex]

Managed to update the submodule.

WorkstationTT:~/development/OpenBoardView$ git submodule
19d02be src/imgui (v1.49-40-g19d02be)

Recompiled, still the same behaviour, so I'm thinking there's a bug in my code.

I'll do some more digging around and see what I find and again, I'll report back 👍

[ocornut]

Thanks! Please build a simplified repro. There's possibly a bug in the code but it's hard to guess anything without seeing much of your code.

[inflex]

I added a bit of debugging code in my program and found essentially what the crux of the issue is;

   ImGuiContext& g = *GImGui;
   fprintf(stderr,"%s =? %s\n", g.CurrentWindow->Name, g.FocusedWindow->Name);

Which, when running, provides the following;

(when not 'focused') surface =? status

(when focused, and scroll zoom working) surface =? surface

For what ever reason, when my program starts up, and when the menu is selected or a dialog used, the focused window becomes "status", and when I click on the draw surface, it finally goes back to 'surface'.

So, I suppose my question is, how do I forcibly make ImGui give focus back to 'surface' when I close the popups or finish the menu handling?

[inflex]

I think I found the problem, if I comment out my status bar code, things magically work nice again :)

ImGuiWindowFlags flags =
        ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoResize |
        ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoScrollbar |
        ImGuiWindowFlags_NoCollapse | ImGuiWindowFlags_NoSavedSettings;
    ImGuiWindowFlags draw_surface_flags = flags |
        ImGuiWindowFlags_NoFocusOnAppearing |
        ImGuiWindowFlags_NoBringToFrontOnFocus;
    ImGui::SetNextWindowPos(ImVec2{0, 0});
    const ImGuiIO &io = ImGui::GetIO();
    if (io.DisplaySize.x != m_lastWidth || io.DisplaySize.y != m_lastHeight) {
        m_lastWidth   = io.DisplaySize.x;
        m_lastHeight  = io.DisplaySize.y;
        m_needsRedraw = true;
    }
    ImGui::SetNextWindowSize(io.DisplaySize);
    ImGui::PushStyleVar(ImGuiStyleVar_WindowRounding, 0.0f);
    ImGui::PushStyleColor(ImGuiCol_WindowBg, ImVec4(0.0f, 0.0f, 0.0f, 0.0f));
    if (m_firstFrame) {
        ImGui::SetNextWindowFocus();
        m_firstFrame = false;
    }
    ImGui::Begin("surface", nullptr, draw_surface_flags);
    HandleInput();
    DrawBoard();
    ImGui::End();
    ImGui::PopStyleColor();

    // Overlay
    RenderOverlay();

    // Status Footer
    float status_height = (10.0f + ImGui::GetFontSize());

    ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(4.0f, 3.0f));
    ImGui::SetNextWindowPos(ImVec2{0, io.DisplaySize.y - status_height});
    ImGui::SetNextWindowSize(ImVec2(io.DisplaySize.x, status_height));
    ImGui::Begin("status", nullptr, flags);
    if (m_file && m_board && m_pinSelected) {
        auto pin = m_pinSelected;
        ImGui::Text("Part: %s   Pin: %s   Net: %s   Probe: %d   (%s.)",
                pin->component->name.c_str(), pin->number.c_str(), pin->net->name.c_str(),
                pin->net->number, pin->component->mount_type_str().c_str());
    } else {
        ImVec2 spos = ImGui::GetMousePos();
        ImVec2 pos  = ScreenToCoord(spos.x, spos.y);
        if (showFPS == true) ImGui::Text("FPS: %0.0f Position: %0.3f\", %0.3f\" (%0.2f, %0.2fmm)", ImGui::GetIO().Framerate, pos.x/1000, pos.y/1000, pos.x *0.0254, pos.y *0.0254 );
        else ImGui::Text("Position: %0.3f\", %0.3f\" (%0.2f, %0.2fmm)", pos.x/1000, pos.y/1000, pos.x *0.0254, pos.y *0.0254 );
    }
    ImGui::End();
    ImGui::PopStyleVar();
    ImGui::PopStyleVar();

[ocornut]

So your Status bar window is taking the focus, but you still haven't provided a repro that shows all the related code, aka how is focus taken away from your surface in the first place (dialogs/menus), so it is hard to tell what's wrong. When possible also try to strip down your repro to the useful bits (aka remove the styling bits) and test it as a standalone piece of code.

When a window appears the first time is automatically takes focus, so that's unnecessary:

    if (m_firstFrame) {
        ImGui::SetNextWindowFocus();
        m_firstFrame = false;
    }

And the fact that you are passing ``ImGuiWindowFlags_NoFocusOnAppearing` to that same window requests the exact contrary here.

And conversely, the status bar will take focus on the first frame as well, unless you pass it the ImGuiWindowFlags_NoFocusOnAppearing flag so that is probably what you want.

[inflex]

Once again @ocornut , many thanks for you time. I have restructured things in the program and changed from IsWindowFocused() to ...IsWindowHovered() which now has resolved all my current issues.

Sorry I couldn't really provide a repro, as I'm not yet fully up to speed with how this program has been written I can't be sure where all the various attributes are being set (until I start reading more, which is usually when I learn where the fault(s) are).