TimeLine tracker. How reduce his code for ImGui

[colesnicov]

(excuse me for my bad english)
Hi guys. I've try to create small MP3 Player and i created timetracker/slider with back propagation and callbacks for formating values for overlays. I grabbed the code from ImGui::ProgresBar(...) and modify is. But i see what its a lot of code. If you see best way to reduce the code or any other hints to modify for better result?

And I don't know why, but the formatting function produce the shits... As You can see on screen the text PA on overlay of tracker did have be float values formatted as f.ff/f.ff :-/

:)

code:

void Tracker(float current, float duration, float* tracked = NULL, const ImVec2& size_arg = ImVec2(-1, 0),
             const char* (*overlay_cb)(float progress, float duration) = nullptr,
             const char* (*tooltip_cb)(float progress, float duration) = nullptr)
{
    // Check for bad values and write is to sto
    const char* error = "";
    if((current > 0.0f && duration == 0.0f) || current > duration) // has error
    {
        std::cerr << "current progress '" << current << "' is too big as total duration '" << duration << "'" << std::endl;
        current = 0.0f;
        error = "error";
    }

    ImGuiWindow* window = ImGui::GetCurrentWindow();
    if (window->SkipItems)
    {
        return;
    }

    ImGuiContext& g = *GImGui;
    const ImGuiStyle& style = g.Style;
    // Calculate BBOX
    ImVec2 pos = window->DC.CursorPos;
    ImRect bb(pos, pos + ImGui::CalcItemSize(size_arg, ImGui::CalcItemWidth(), g.FontSize + style.FramePadding.y*2.0f));
    ImGui::ItemSize(bb, style.FramePadding.y);
    if (!ImGui::ItemAdd(bb, NULL))
    {
        return;
    }

    // Render tracker
    current = 1.0f / (duration / current);
    ImGui::RenderFrame(bb.Min, bb.Max, ImGui::GetColorU32(ImGuiCol_FrameBg), true, style.FrameRounding);
    bb.Reduce(ImVec2(window->BorderSize, window->BorderSize));
    const ImVec2 fill_br = ImVec2(ImLerp(bb.Min.x, bb.Max.x, current), bb.Max.y);
    ImGui::RenderFrame(bb.Min, fill_br, ImGui::GetColorU32(ImGuiCol_PlotHistogram), false, style.FrameRounding);

    // Stop render if has error
    if(strlen(error)>0)
    {
        ImGui::RenderText(ImVec2(bb.Min + (bb.GetSize() - ImGui::CalcTextSize(error)) / 2), error);
        return;
    }
    // Calculate overlap
    ImVec2 bb_closets = bb.GetClosestPoint(ImGui::GetIO().MousePos, true);
    float mousePosition = bb_closets.x - pos.x;
    float percent =1.0f / (bb.GetSize().x / mousePosition);

    if(duration > 0.0f)
    {
        // Check if hovered and clicked
        //ImGuiButtonFlags button_flags = ImGuiButtonFlags_PressedOnClick|ImGuiButtonFlags_PressedOnClickRelease|ImGuiButtonFlags_PressedOnRelease
        bool hovered;
        bool pressed = ImGui::ButtonBehavior(bb, NULL, &hovered, NULL, ImGuiButtonFlags_PressedOnClick);

        if(pressed && tracked) // Has click event
        {
            *tracked = percent * 100;
        }

        if(hovered) // Has hover event
        {
            // Render overlap
            ImGui::RenderFrame(bb.Min, ImVec2(ImLerp(bb.Min.x, bb.Max.x, percent), bb.Max.y), ImColor(180, 180, 255, 150), false, style.FrameRounding);
            if(tooltip_cb != nullptr) // Has on mouse hover callback for tooltip format
            {
                const char* tooltip = tooltip_cb(percent, duration);
                ImGui::SetTooltip("%s", tooltip);
            }
        }
    }

    if (overlay_cb != nullptr) // Has overlay format callback
    {
        // Calculate BBOX and render overlay text
        const char* overlay = overlay_cb(percent, duration);
        ImVec2 overlay_size = ImGui::CalcTextSize(overlay);
        ImGui::RenderText(ImVec2(bb.Min + (bb.GetSize() - overlay_size) / 2), overlay);
    }
}

usage:

ImGui::Begin("Time tracker", NULL, ImGuiWindowFlags_ShowBorders);
{
  static float current = 0.0f;
  float duration = 10.0f;
  float tracked = 0.0f;
  siz(300, 50);
  Tracker(current, duration, &tracked, siz, [](float progress, float duration) -> const char*
  {
    char buf[50];
    ImFormatString(buf, IM_ARRAYSIZE(buf), "%.2f/%.2f", progress, duration);
    const char* str(buf);
    return str;
    });
  ImGui::SliderFloat("Current", &current, .0f, 100.f);
  ImGui::SliderFloat("Duration", &duration, .0f, 100.f);
  ImGui::Text("Tracked: %f", tracked);
}
ImGui::End();