NewFrame creates decorated window ?

[PinkMushroom]

I'm running some test code to learn imgui and it generates a frame labeled "Debug" along with a little button that collapses the frame, i.e. it looks like a mini-window (it can be resized too).

The problem is i'm not creating a gui element with a button, and there's no text "Debug" anywhere in my code, it looks like it's being created by default by NewFrame.

So the two questions are:
1 what is generating the labeling and decoration
2 how do i control it, for example, the frame can be resized. Can i make it a fixed size ?

[Gnimuc]

I need the version and environment info and the code to reproduce the issue.

[PinkMushroom]

CImGui v1.79.0
Julia 1.6.1
Linux

I'm not exactly sure what the "environment info" is.
Code is included. Sorry that it's a bit long.

using CImGui
using CImGui.CSyntax
using CImGui.CSyntax.CStatic
using CImGui: ImVec2, IM_COL32, ImU32, FLT_MAX, ImGuiSizeCallbackData

# GLFW related

using CImGui.GLFWBackend
using CImGui.OpenGLBackend
using CImGui.GLFWBackend.GLFW
using CImGui.OpenGLBackend.ModernGL

#
# This test code specifically does NOT use the Render module
#

const _debug = 0
glsl_version = 130

function __init__()
    println("__init__")
    @static if Sys.isapple()
        # OpenGL 3.2 + GLSL 150
        global glsl_version = 150
        GLFW.WindowHint(GLFW.CONTEXT_VERSION_MAJOR, 3)
        GLFW.WindowHint(GLFW.CONTEXT_VERSION_MINOR, 2)
        GLFW.WindowHint(GLFW.OPENGL_PROFILE, GLFW.OPENGL_CORE_PROFILE) # 3.2+ only
        GLFW.WindowHint(GLFW.OPENGL_FORWARD_COMPAT, GL_TRUE) # required on Mac
    else
        # OpenGL 3.0 + GLSL 130
        global glsl_version = 130
        GLFW.WindowHint(GLFW.CONTEXT_VERSION_MAJOR, 3)
        GLFW.WindowHint(GLFW.CONTEXT_VERSION_MINOR, 0)
        # GLFW.WindowHint(GLFW.OPENGL_PROFILE, GLFW.OPENGL_CORE_PROFILE) # 3.2+ only
        # GLFW.WindowHint(GLFW.OPENGL_FORWARD_COMPAT, GL_TRUE) # 3.0+ only
    end
end

error_callback(err::GLFW.GLFWError) = @error "GLFW ERROR: code $(err.code) msg: $(err.description)"

function main()
    width = 800
    height = 480
    title = "Test3"

    __init__()
    
    # setup GLFW error callback
    GLFW.SetErrorCallback(error_callback)

    # create window
    window = GLFW.CreateWindow(width, height, title)
    @assert window != C_NULL
    GLFW.MakeContextCurrent(window)
    GLFW.SwapInterval(1)  # enable vsync

    # setup Dear ImGui context
    ctx = CImGui.CreateContext()

    # setup Dear ImGui style
    CImGui.StyleColorsDark()
    # CImGui.StyleColorsClassic()
    # CImGui.StyleColorsLight()

    # setup Platform/Renderer bindings
    ImGui_ImplGlfw_InitForOpenGL(window, true)
    ImGui_ImplOpenGL3_Init(glsl_version)

    try
        while !GLFW.WindowShouldClose(window)
            GLFW.PollEvents()
            ImGui_ImplOpenGL3_NewFrame()
            ImGui_ImplGlfw_NewFrame()
            CImGui.NewFrame()

            io = CImGui.GetIO()
            canvas_p0 = CImGui.GetCursorScreenPos()
            canvas_sz = CImGui.GetContentRegionAvail()
            x = canvas_sz.x
            y = canvas_sz.y
            if x < 50.0
                x = 50.0
            end
            if y < 50.0
                y = 50.0
            end
            canvas_p1 = ImVec2(canvas_p0.x + x, canvas_p0.y + y)
            scrolling = ImVec2(0.0, 0.0)
            drawing_line = false

            draw_list = CImGui.GetWindowDrawList()

            # canvas background
            CImGui.AddRectFilled(draw_list, canvas_p0, canvas_p1, IM_COL32(50, 50, 150, 255))
            # canvas border
            # this appears to be 1 px in width
            CImGui.AddRect(draw_list, canvas_p0, canvas_p1, IM_COL32(255, 0, 255, 255))

            CImGui.InvisibleButton("canvas",
                                   canvas_sz,
                                   CImGui.ImGuiButtonFlags_MouseButtonLeft | CImGui.ImGuiButtonFlags_MouseButtonRight)

            origin = ImVec2(canvas_p0.x + scrolling.x, canvas_p0.y + scrolling.y)
            mouse_pos_in_canvas = ImVec2(io.MousePos.x - origin.x,
                                         io.MousePos.y - origin.y)

            is_hovered = CImGui.IsItemHovered()
            is_active = CImGui.IsItemActive()
            # This is set to 1 when the mouse button is pressed and does not
            # get reset until it is released
            is_clicked = CImGui.IsMouseClicked(CImGui.ImGuiMouseButton_Left)

            if _debug > 0
                println("is_hovered:", is_hovered,
                        " is_active:", is_active,
                        " is_clicked:", is_clicked)
            end
            
            if is_hovered && !drawing_line && is_clicked
                println("---")
                println("canvas_p0=", canvas_p0)
                println("canvas_p1=", canvas_p1)
                println("canvas_sz=", canvas_sz)
                println("mouse_pos_in_canvas:", mouse_pos_in_canvas)
                println("origin:", origin)
                println("draw_list=", draw_list)

                # not really sure what the begin/end is supposed to delimit

                # "io" seems to encapsulate a lot of information
                println("Line Start x y:", io.MousePos.x, io.MousePos.y)
            end

            # active a clipping rectangle
            
            CImGui.PushClipRect(draw_list, canvas_p0, canvas_p1, true)

            # draw the "rubber banding" line

            
            CImGui.PopClipRect(draw_list)
            
            CImGui.End()

            CImGui.Render()
            GLFW.MakeContextCurrent(window)
            display_w, display_h = GLFW.GetFramebufferSize(window)
            glViewport(0, 0, display_w, display_h)
            glClearColor(0.2, 0.2, 0.2, 1)
            glClear(GL_COLOR_BUFFER_BIT)
            ImGui_ImplOpenGL3_RenderDrawData(CImGui.GetDrawData())

            GLFW.MakeContextCurrent(window)
            GLFW.SwapBuffers(window)
            yield()
        end
    catch e
        @error "Error in renderloop!" exception=e
        Base.show_backtrace(stderr, catch_backtrace())
    finally
        ImGui_ImplOpenGL3_Shutdown()
        ImGui_ImplGlfw_Shutdown()
        CImGui.DestroyContext(ctx)
        GLFW.DestroyWindow(window)
    end
end

main()

[Gnimuc]

I didn't see CImGui.Begin(...) is being called anywhere.

[Gnimuc]

Please refer to https://github.com/Gnimuc/CImGui.jl/blob/ee509988dda4472dac44384734119d9ad849f999/examples/demo_window.jl#L80-L91 for how to control window style.