CPP

ImGui Menu Bar

bool HY_ImGui_BeginMainStatusBar()
{
    ImGuiContext& g = *GImGui;
    ImGuiViewportP* viewport = g.Viewports[0];
    ImGuiWindow* menu_bar_window = ImGui::FindWindowByName("##MainStatusBar");
    
    // For the main menu bar, which cannot be moved, we honor g.Style.DisplaySafeAreaPadding to ensure text can be visible on a TV set.
    g.NextWindowData.MenuBarOffsetMinVal = ImVec2(g.Style.DisplaySafeAreaPadding.x, ImMax(g.Style.DisplaySafeAreaPadding.y - g.Style.FramePadding.y, 0.0f));
    
    // Get our rectangle at the top of the work area
    //__debugbreak();
    if (menu_bar_window == NULL || menu_bar_window->BeginCount == 0)
    {
        // Set window position
        // We don't attempt to calculate our height ahead, as it depends on the per-viewport font size. However menu-bar will affect the minimum window size so we'll get the right height.
        ImVec2 menu_bar_pos = viewport->Pos + viewport->CurrWorkOffsetMin;
        ImVec2 menu_bar_size = ImVec2(viewport->Size.x - viewport->CurrWorkOffsetMin.x + viewport->CurrWorkOffsetMax.x, 1.0f);
        ImGui::SetNextWindowPos(menu_bar_pos);
        ImGui::SetNextWindowSize(menu_bar_size);
    }
    
    // Create window
    ImGui::SetNextWindowViewport(viewport->ID); // Enforce viewport so we don't create our own viewport when ImGuiConfigFlags_ViewportsNoMerge is set.
    ImGui::PushStyleVar(ImGuiStyleVar_WindowRounding, 0.0f);
    ImGui::PushStyleVar(ImGuiStyleVar_WindowMinSize, ImVec2(0, 0));    // Lift normal size constraint, however the presence of a menu-bar will give us the minimum height we want.
    ImGuiWindowFlags window_flags = ImGuiWindowFlags_NoDocking | ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoSavedSettings | ImGuiWindowFlags_MenuBar;
    bool is_open = ImGui::Begin("##MainStatusBar", NULL, window_flags) && ImGui::BeginMenuBar();
    ImGui::PopStyleVar(2);
    
    // Report our size into work area (for next frame) using actual window size
    menu_bar_window = ImGui::GetCurrentWindow();
    if (menu_bar_window->BeginCount == 1)
        viewport->CurrWorkOffsetMin.y += menu_bar_window->Size.y; 
    
    g.NextWindowData.MenuBarOffsetMinVal = ImVec2(0.0f, 0.0f);
    if (!is_open)
    {
        ImGui::End();
        return false;
    }
    return true; //-V1020
}

void HY_ImGui_EndMainStatusBar()
{
    ImGui::EndMenuBar();
    
    // When the user has left the menu layer (typically: closed menus through activation of an item), we restore focus to the previous window
    // FIXME: With this strategy we won't be able to restore a NULL focus.
    ImGuiContext& g = *GImGui;
    if (g.CurrentWindow == g.NavWindow && g.NavLayer == ImGuiNavLayer_Main && !g.NavAnyRequest)
        ImGui::FocusTopMostWindowUnderOne(g.NavWindow, NULL);
    
    ImGui::End();
}