src/imrad.h

#pragma once
#include <string>
#include <vector>
#include <memory>
#include <functional> //for ModalPopup callback
#include <fstream> //Save/LoadStyle
#include <filesystem> //Save/LoadStyle
#include <iomanip> //std::quoted
#include <sstream>
#include <map>
#include <imgui.h>
#include <imgui_internal.h> //CurrentItemFlags, GetCurrentWindow, PushOverrideID
#include <misc/cpp/imgui_stdlib.h> //for Input(std::string)

#ifdef IMRAD_WITH_FMT
#include <fmt/format.h>
#elif __cplusplus >= 202002L && __has_include(<format>)
#include <format>
#endif

#ifdef IMRAD_WITH_GLFW
#include <GLFW/glfw3.h> //enables kind=MainWindow
#ifndef GL_CLAMP_TO_EDGE
#define GL_CLAMP_TO_EDGE 0x812F
#endif
#ifdef IMRAD_WITH_STB
#include <stb_image.h> //for LoadTextureFromFile
#endif
#endif

#define IMRAD_INPUTTEXT_EVENT(clazz, member) \
    [](ImGuiInputTextCallbackData* data) { return ((clazz*)data->UserData)->member(*data); }, this

namespace ImRad {

using Int2 = int[2];
using Int3 = int[3];
using Int4 = int[4];
using Float2 = float[2];
using Float3 = float[3];
using Float4 = float[4];
using Color3 = ImVec4;
using Color4 = ImVec4;

enum ModalResult {
    None = 0,
    Ok = 0x1,
    Cancel = 0x2,
    Yes = 0x4,
    No = 0x8,
    Abort = 0x10,
    Retry = 0x20,
    Ignore = 0x40,
    All = 0x80, //deprecated
    YesToAll = 0x80,
    NoToAll = 0x100,
    Apply = 0x200,
    Discard = 0x400,
    Help = 0x800,
    Reset = 0x1000,
};

enum Alignment {
    AlignNone = 0x0,
    AlignLeft = 0x1,
    AlignRight = 0x2,
    AlignHCenter = 0x4,
    AlignTop = 0x8,
    AlignBottom = 0x10,
    AlignVCenter = 0x20,
};

enum ImeType {
    ImeText = 1,
    ImeNumber = 2,
    ImeDecimal = 3,
    ImePhone = 4,
    ImeEmail = 5,

    ImeActionDone = 0x100,
    ImeActionGo = 0x200,
    ImeActionNext = 0x300,
    ImeActionPrevious = 0x400,
    ImeActionSearch = 0x500,
    ImeActionSend = 0x600,
};

struct Texture
{
    ImTextureID id = 0;
    int w, h;
    explicit operator bool() const { return id != 0; }
};

struct CustomWidgetArgs
{
    ImVec2 size;

    CustomWidgetArgs(const ImVec2& sz) : size(sz) {}
    CustomWidgetArgs(float x, float y) : size(x, y) {}
};

struct IOUserData
{
    //to UI
    float dpiScale = 1;
    ImVec2 displayOffsetMin;
    ImVec2 displayOffsetMax;
    float dimBgRatio = 1;
    bool kbdShown = false;
    std::string activeActivity;
    //from UI
    int imeType = ImeText;
    ImGuiID longPressID = 0;

    ImRect WorkRect() const
    {
        return {
            displayOffsetMin.x,
            displayOffsetMin.y,
            ImGui::GetMainViewport()->Size.x - displayOffsetMax.x,
            ImGui::GetMainViewport()->Size.y - displayOffsetMax.y };
    }
};

struct Animator
{
    //todo: configure
    static inline const float DurOpenPopup = 0.4f;
    static inline const float DurClosePopup = 0.3f;

    void StartAlways(float *v, float s, float e, float dur)
    {
        Var nvar{ 0, v, s, e, dur, false };
        for (auto& var : vars)
            if (var.var == v) {
                var = nvar;
                return;
            }
        vars.push_back(nvar);
    }
    void StartOnce(float *v, float s, float e, float dur)
    {
        Var nvar{ 0, v, s, e, dur, true };
        for (auto& var : vars)
            if (var.var == v) {
                var = nvar;
                return;
            }
        vars.push_back(nvar);
    }
    bool IsDone() const
    {
        for (const auto& var : vars)
            if (var.oneShot || std::abs(*var.var - var.end) / std::abs(var.end - var.start) > 0.01)
                return false;
        return true;
    }
    //to be called from withing Begin
    void Tick()
    {
        wsize = ImGui::GetCurrentWindow()->Size; //cache actual windows size
        size_t j = 0;
        for (size_t i = 0; i < vars.size(); ++i) {
            auto& var = vars[i];
            var.time += ImGui::GetIO().DeltaTime;
            float distance = var.end - var.start;
            float x = var.time / var.duration;
            if (x > 1)
                x = 1.f;
            float y = 1 - (1 - x) * (1 - x); //easeOutQuad
            *var.var = var.start + y * distance;
            if (!var.oneShot || std::abs(x - 1.0) >= 0.01) { //keep current var
                if (j < i)
                    vars[j] = var;
                ++j;
            }
        }
        vars.resize(j);
    }
    ImVec2 GetWindowSize() const
    {
        return wsize;
    }

private:
    struct Var
    {
        float time;
        float* var = nullptr;
        float start, end;
        float duration;
        bool oneShot;
    };
    std::vector<Var> vars;
    ImVec2 wsize{ 0, 0 };
};


template <bool HORIZ>
struct BoxLayout
{
    static constexpr float ItemSize = 0;

    struct Stretch {
        float value;
        Stretch(float v) : value(v) {}
    };

    void Reset()
    {
        prevItems.clear();
    }
    void BeginLayout()
    {
        pos1 = HORIZ ? ImGui::GetCursorPosX() : ImGui::GetCursorPosY();
        std::swap(prevItems, items);
        items.clear();

        float avail = HORIZ ? ImGui::GetContentRegionAvail().x : ImGui::GetContentRegionAvail().y;
        float total = 0;
        float stretchTotal = 0;
        for (Item& it : prevItems) {
            //it.spacing = (int)it.spacing;
            //it.size = (int)it.size;
            total += it.spacing;
            if (it.stretch)
                stretchTotal += it.size;
            else if (it.size < 0) {
                //total = avail + it.size;
                stretchTotal += 1.0;
                total += -it.size;
            }
            else
                total += it.size;
        }
        for (Item& it : prevItems) {
            if (it.stretch)
                it.size = (float)(int)(it.size * (avail - total) / stretchTotal);
            else if (it.size < 0)
                it.size = (float)(int)(1.0 * (avail - total) / stretchTotal);
                //it.size += avail;
        }
    }
    //call after a widget call
    void AddSize(int sp, float size)
    {
        float spacing = sp * (HORIZ ? ImGui::GetStyle().ItemSpacing.x : ImGui::GetStyle().ItemSpacing.y);
        if (size == ItemSize)
            size = HORIZ ? ImGui::GetItemRectSize().x : ImGui::GetItemRectSize().y;
        items.push_back({ spacing, size, false });
    }
    void AddSize(int sp, Stretch size)
    {
        float spacing = sp * (HORIZ ? ImGui::GetStyle().ItemSpacing.x : ImGui::GetStyle().ItemSpacing.y);
        items.push_back({ spacing, size.value, true });
    }
    //call after a widget call for vert layout having multiple widgets in a row
    void UpdateSize(float sp, float size)
    {
        assert(items.size());
        float spacing = sp * (HORIZ ? ImGui::GetStyle().ItemSpacing.x : ImGui::GetStyle().ItemSpacing.y);
        if (size == ItemSize)
            size = HORIZ ? ImGui::GetItemRectSize().x : ImGui::GetItemRectSize().y;
        Item& it = items.back();
        if (spacing > it.spacing)
            it.spacing = spacing;
        if (!it.stretch && (size > it.size || (size < 0 && it.size > 0)))
            it.size = size;
    }
    void UpdateSize(float sp, Stretch size)
    {
        assert(items.size());
        float spacing = sp * (HORIZ ? ImGui::GetStyle().ItemSpacing.x : ImGui::GetStyle().ItemSpacing.y);
        Item& it = items.back();
        if (spacing > it.spacing)
            it.spacing = spacing;
        if (!it.stretch || size.value > it.size) {
            it.stretch = true;
            it.size = size.value;
        }
    }
    //unused - for use in SetCursorX/Y
    float GetPos()
    {
        if (prevItems.size() <= items.size()) //stop positioning - widgets changed
            return HORIZ ? ImGui::GetCursorPosX() : ImGui::GetCursorPosY();
        float pos = pos1;
        for (size_t i = 0; i < items.size(); ++i) {
            pos += prevItems[i].size + prevItems[i].spacing;
        }
        if (prevItems.size() > items.size())
            pos += prevItems[items.size()].spacing;
        return pos;
    }
    //deprecated
    operator float()
    {
        return GetPos();
    }
    //for use in SetNextItemWidth/ctor. Call after possible SameLine
    float GetSize(bool deprecatedSameLine = false)
    {
        bool sameLine = !HORIZ && ImGui::GetCurrentWindow()->DC.IsSameLine;
        size_t i = sameLine ? items.size() - 1 : items.size();
        if (i >= prevItems.size()) //widgets changed
            return 0;
        return prevItems[i].size;
    }

private:
    struct Item {
        float spacing;
        float size;
        bool stretch;
    };

    std::vector<Item> items, prevItems;
    float pos1;
};

using HBox = BoxLayout<true>;
using VBox = BoxLayout<false>;

//------------------------------------------------------------------------

#ifdef ANDROID
extern int GetAssetData(const char* filename, void** outData);
#endif

inline bool Combo(const char* label, std::string* curr, const std::vector<std::string>& items, int flags = 0)
{
    bool changed = false;
    if (ImGui::BeginCombo(label, curr->c_str(), flags))
    {
        for (const auto& item : items) {
            if (ImGui::Selectable(item.c_str(), item == *curr)) {
                *curr = item;
                changed = true;
            }
        }
        ImGui::EndCombo();
    }
    return changed;
}

inline bool Combo(const char* label, std::string* curr, const char* items, int flags = 0)
{
    bool changed = false;
    if (ImGui::BeginCombo(label, curr->c_str(), flags))
    {
        const char* p = items;
        while (*p) {
            if (ImGui::Selectable(p, !curr->compare(p))) {
                *curr = p;
                changed = true;
            }
            p += strlen(p) + 1;
        }
        ImGui::EndCombo();
    }
    return changed;
}

inline void Dummy(const ImVec2& size)
{
    //ImGui Dummy doesn't support negative dimensions like other controls
    ImVec2 sz = ImGui::CalcItemSize(size, 0, 0);
    return ImGui::Dummy(sz);
}

//ImGui::Selectable behaves differently in many ways. Here we
// * use CalcItemSize to support negative dimensions
// * change meaning of size.x=0 to label width. This fixes layout calculation in box sizer because
// ImGui::Selectable always reports avail. User can still supply -1 to request avail width expansion
// * size.y=0 doesn't cause avail width expansion in ImGui so changing size.x=0 fixes the inconsistency
inline bool Selectable(const char* label, bool selected, ImGuiSelectableFlags flags, const ImVec2& size)
{
    ImVec2 sz = ImGui::CalcItemSize(size, 0, 0);
    if (!sz.x && !(flags & ImGuiSelectableFlags_SpanAllColumns))
        sz.x = ImGui::CalcTextSize(label, nullptr, true).x;
    return ImGui::Selectable(label, selected, flags, sz);
}

inline bool Selectable(const char* label, bool* selected, ImGuiSelectableFlags flags, const ImVec2& size)
{
    if (Selectable(label, *selected, flags, size)) {
        *selected = !*selected;
        return true;
    }
    return false;
}

inline bool Splitter(bool split_horiz, float thickness, float* position, float min_size1, float min_size2, float splitter_long_axis_size = -1.0f)
{
    using namespace ImGui;
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;
    ImGuiID id = window->GetID("##Splitter");
    ImRect bb;
    bb.Min = window->DC.CursorPos;
    bb.Min[!split_horiz] += *position;

    bb.Max = bb.Min;
    ImVec2 sz(thickness, splitter_long_axis_size);
    if (!split_horiz)
        std::swap(sz[0], sz[1]);
    sz = CalcItemSize(sz, 0.0f, 0.0f);
    bb.Max[0] += sz[0];
    bb.Max[1] += sz[1];

    float tmp = ImGui::GetContentRegionAvail().x - *position - thickness;
    return SplitterBehavior(bb, id, split_horiz ? ImGuiAxis_X : ImGuiAxis_Y, position, &tmp, min_size1, min_size2, 0.0f);
}

inline bool IsItemDoubleClicked()
{
    return ImGui::IsMouseDoubleClicked(ImGuiMouseButton_Left) && ImGui::IsItemHovered();
}

inline bool IsItemContextMenuClicked()
{
    return ImGui::IsMouseReleased(ImGuiPopupFlags_MouseButtonDefault_) &&
        ImGui::IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup);
}

inline bool IsItemLongPressed(double dur = -1)
{
    if (dur < 0)
        dur = 0.5f;
    double time = ImGui::GetTime() - ImGui::GetIO().MouseClickedTime[ImGuiMouseButton_Left];
    return ImGui::IsMouseDown(ImGuiMouseButton_Left) &&
        !ImGui::IsMouseDragging(ImGuiMouseButton_Left) &&
        ImGui::IsItemHovered() &&
        time > dur;
}

inline bool IsItemImeAction()
{
    return ImGui::IsItemActive() && ImGui::IsKeyPressed(ImGuiKey_AppForward);
}

inline bool IsCurrentItemDisabled()
{
    return ImGui::GetCurrentContext()->CurrentItemFlags & ImGuiItemFlags_Disabled;
}

//allows to define popups in the window and open it from widgets calling internally
//Push/PopID like TabControl
inline void OpenWindowPopup(const char* str_id, ImGuiPopupFlags flags = 0)
{
    //RootWindow skips child window parents
    ImGui::PushOverrideID(ImGui::GetCurrentWindow()->RootWindow->ID);
    //todo: for drop down menu use button's BL corner
    ImGui::OpenPopup(str_id, flags);
    ImGui::PopID();
}

inline ImRect GetParentInnerRect()
{
    ImRect r = ImGui::GetCurrentWindow()->InnerRect;
    if (ImGui::GetCurrentTable())
        r.ClipWith(ImGui::GetCurrentTable()->InnerRect);
    return r;
}

inline void Spacing(int n)
{
    /*while (n--)
        ImGui::Spacing();*/
    /*ImGuiWindow* window = ImGui::GetCurrentWindow();
    if (window->SkipItems)
        return;*/
    float sp = ImGui::GetStyle().ItemSpacing.y;
    ImGui::SetCursorPosY(ImGui::GetCursorPosY() + n * sp);
}

inline bool TableNextColumn(int n)
{
    bool b;
    while (n--)
        b = ImGui::TableNextColumn();
    return b;
}

inline void NextColumn(int n)
{
    while (n--)
        ImGui::NextColumn();
}

inline void PushInvisibleScrollbar()
{
    ImVec4 clr = ImGui::GetStyleColorVec4(ImGuiCol_ScrollbarBg);
    ImGui::PushStyleColor(ImGuiCol_ScrollbarBg, { clr.x, clr.y, clr.z, 0 });
    clr = ImGui::GetStyleColorVec4(ImGuiCol_ScrollbarGrab);
    ImGui::PushStyleColor(ImGuiCol_ScrollbarGrab, { clr.x, clr.y, clr.z, 0 });
}

inline void PopInvisibleScrollbar()
{
    ImGui::PopStyleColor(2);
}

struct CursorData
{
    ImVec2 cursorPos; //affects column border height
    ImVec2 cursorPosPrevLine; //used in SameLine
    ImVec2 prevLineSize;
    float prevLineTextBaseOffset;
    ImVec2 cursorMaxPos; //affects scrollbars
    ImVec2 idealMaxPos; //affects auto resize
};

inline CursorData GetCursorData()
{
    CursorData data;
    ImGuiWindow* wnd = ImGui::GetCurrentWindow();
    data.cursorPos = wnd->DC.CursorPos; 
    data.cursorPosPrevLine = wnd->DC.CursorPosPrevLine;
    data.prevLineSize = wnd->DC.PrevLineSize;
    data.prevLineTextBaseOffset = wnd->DC.PrevLineTextBaseOffset;
    data.cursorMaxPos = wnd->DC.CursorMaxPos; 
    data.idealMaxPos = wnd->DC.IdealMaxPos; 
    return data;
}

inline void SetCursorData(const CursorData& data)
{
    ImGuiWindow* wnd = ImGui::GetCurrentWindow();
    wnd->DC.CursorPos = data.cursorPos;
    wnd->DC.CursorPosPrevLine = data.cursorPosPrevLine;
    wnd->DC.PrevLineSize = data.prevLineSize;
    wnd->DC.PrevLineTextBaseOffset = data.prevLineTextBaseOffset;
    wnd->DC.CursorMaxPos = data.cursorMaxPos;
    wnd->DC.IdealMaxPos = data.idealMaxPos;
}

inline const ImGuiLastItemData& GetLastItemData()
{
    return ImGui::GetCurrentContext()->LastItemData;
}

inline void SetLastItemData(const ImGuiLastItemData& data)
{
    ImGui::GetCurrentContext()->LastItemData = data;
}

struct IgnoreWindowPaddingData
{
    ImVec2 maxPos;
    ImVec2 workRectMax;
    bool hasSize;
};

inline void PushIgnoreWindowPadding(ImVec2* sz, IgnoreWindowPaddingData* data)
{
    ImGuiWindow* wnd = ImGui::GetCurrentWindow();
    data->hasSize = sz != nullptr;
    data->maxPos = wnd->DC.CursorMaxPos;
    data->workRectMax = wnd->WorkRect.Max;
    ImRect r = wnd->InnerRect;
    float fixbs = wnd->WindowBorderSize ? 1.f : 0; //not sure why imgui renders some additional border shadow
    r.Min.x += fixbs;
    r.Max.x -= fixbs;
    ImGui::PushClipRect(r.Min, r.Max, false);
    ImVec2 pos = ImGui::GetCursorScreenPos();
    if (pos.x <= wnd->DC.CursorStartPos.x)
        pos.x = r.Min.x + fixbs;
    if (pos.y <= wnd->DC.CursorStartPos.y)
        pos.y = r.Min.y;
    ImGui::SetCursorScreenPos(pos);
    wnd->WorkRect.Max.x = r.Max.x; //used by Separator
    //+1 here is to exactly map sz=-1 to right/bottom edge
    if (sz && sz->x < 0)
        sz->x = r.Max.x + sz->x + 1 - pos.x;
    if (sz && sz->y < 0)
        sz->y = r.Max.y + sz->y + 1 - pos.y;
}

inline void PopIgnoreWindowPadding(const IgnoreWindowPaddingData& data)
{
    ImGuiWindow* wnd = ImGui::GetCurrentWindow();
    wnd->WorkRect.Max = data.workRectMax;
    if (data.hasSize)
    {
        ImVec2 pad = wnd->WindowPadding;
        if (wnd->DC.CursorMaxPos.x > data.maxPos.x)
            wnd->DC.CursorMaxPos.x -= pad.x;
        if (wnd->DC.CursorMaxPos.y > data.maxPos.y)
            wnd->DC.CursorMaxPos.y -= pad.y;
    }
    ImGui::PopClipRect();
}

//optionally draws scrollbars so they can be kept hidden when no scrolling occurs
//returns:
//0 - nothing happening or scrolling continues
//1 - scrolling started
//2 - scrolling ended
inline int ScrollWhenDragging(bool drawScrollbars)
{
    static int dragState = 0;

    if (!ImGui::IsWindowFocused())
        return 0;

    if (ImGui::IsMouseDragging(ImGuiMouseButton_Left))
    {
        int ret = !dragState ? 1 : 0;
        dragState = 1;
        ImGuiWindow *window = ImGui::GetCurrentWindow();
        ImGui::GetCurrentContext()->NavHighlightItemUnderNav = true;
        ImVec2 delta = ImGui::GetMouseDragDelta(ImGuiMouseButton_Left);
        if (delta.x)
            ImGui::SetScrollX(window, window->Scroll.x - delta.x);
        if (delta.y)
            ImGui::SetScrollY(window, window->Scroll.y - delta.y);
        ImGui::ResetMouseDragDelta(ImGuiMouseButton_Left);

        //scrollbars were made invisible, draw them again
        if (drawScrollbars)
        {
            bool tmp = window->SkipItems;
            window->SkipItems = false;
            ImGui::PushClipRect(window->Rect().Min, window->Rect().Max, false);
            ImVec4 clr = ImGui::GetStyleColorVec4(ImGuiCol_ScrollbarGrab);
            ImGui::PushStyleColor(ImGuiCol_ScrollbarGrab, { clr.x, clr.y, clr.z, 1 });
            if (window->ScrollbarX)
                ImGui::Scrollbar(ImGuiAxis_X);
            if (window->ScrollbarY)
                ImGui::Scrollbar(ImGuiAxis_Y);
            ImGui::PopStyleColor();
            ImGui::PopClipRect();
            window->SkipItems = tmp;
        }
        return ret;
    }
    else if (dragState == 1)
    {
        dragState = 0;
        ImGui::GetCurrentContext()->NavHighlightItemUnderNav = false;
        ImGui::GetIO().MousePos = { -FLT_MAX, -FLT_MAX }; //ignore mouse release event, buttons won't get pushed
        return 2;
    }

    return 0;
}

//this currently
//* allows to move popups on the screen side further out of the screen just to give it responsive feeling
//* detects modal/popup close event
//returns
// 0 - close popup either by sliding or clicking outside
// 1 - nothing happening
// 2 - todo: maximize up/down popup
inline int MoveWhenDragging(ImGuiDir dir, ImVec2& pos, float& dimBgRatio)
{
    static int dragState = 0;
    static ImVec2 mousePos[3];
    static ImVec2 startPos, lastPos;
    static float lastDim;

    if (ImGui::IsWindowFocused())
    {
        if (ImGui::IsMouseDragging(ImGuiMouseButton_Left))
        {
            if (!dragState)
            {
                startPos = pos;
                mousePos[1] = mousePos[2] = ImGui::GetMousePos();
            }
            dragState = 1;
            mousePos[0] = mousePos[1];
            mousePos[1] = mousePos[2];
            mousePos[2] = ImGui::GetMousePos();
            ImGuiWindow *window = ImGui::GetCurrentWindow();
            ImGui::GetCurrentContext()->NavHighlightItemUnderNav = true;

            ImVec2 delta = ImGui::GetMouseDragDelta(ImGuiMouseButton_Left);
            //don't reset DragDelta - we need to apply full delta if pos
            //was externally modified with Animator
            //ImGui::ResetMouseDragDelta(ImGuiMouseButton_Left);
            if (dir == ImGuiDir_Left) {
                pos.x = startPos.x + delta.x;
                dimBgRatio = (window->Size.x + pos.x) / window->Size.x;
            }
            else if (dir == ImGuiDir_Right) {
                pos.x = startPos.x - delta.x;
                dimBgRatio = (window->Size.x + pos.x) / window->Size.x;
            }
            else if (dir == ImGuiDir_Up) {
                pos.y = startPos.y + delta.y;
                dimBgRatio = (window->Size.y + pos.y) / window->Size.y;
            }
            else if (dir == ImGuiDir_Down) {
                pos.y = startPos.y - delta.y;
                dimBgRatio = (window->Size.y + pos.y) / window->Size.y;
            }
            if (pos.x > 0) {
                pos.x = 0;
                dimBgRatio = 1;
            }
            if (pos.y > 0) {
                pos.y = 0;
                dimBgRatio = 1;
            }
            lastPos = pos;
            lastDim = dimBgRatio;
        }
        else if (dragState == 1)
        {
            //apply lastPos because position could be rewritten by Animator but the real value
            //needs to be taken for next closing animation
            pos = lastPos;
            dimBgRatio = lastDim;
            dragState = 0;
            ImGui::GetCurrentContext()->NavHighlightItemUnderNav = false;
            ImGui::GetIO().MousePos = { -FLT_MAX, -FLT_MAX }; //ignore mouse release event, buttons won't get pushed

            float spx = (mousePos[2].x - mousePos[0].x) / 2;
            float spy = (mousePos[2].y - mousePos[0].y) / 2;
            if (dir == ImGuiDir_Left && spx < -5)
                return 0;
            if (dir == ImGuiDir_Right && spx > 5)
                return 0;
            if (dir == ImGuiDir_Up && spy < -5)
                return 0;
            if (dir == ImGuiDir_Down && spy > 5)
                return 0;
        }
    }

    if (ImGui::IsMouseClicked(0) && !ImGui::IsWindowHovered(ImGuiHoveredFlags_ChildWindows))
    {
        ImGui::GetIO().MouseClicked[0] = false; //eat event
        return 0;
    }

    return 1;
}

//todo
//intended for android
//original version doesn't respect ioUserData.displayMinMaxOffset
inline void RenderDimmedBackground(const ImRect& rect, float alpha_mul)
{
    ImGui::GetStyle().Colors[ImGuiCol_ModalWindowDimBg] = ImVec4(0, 0, 0, 0); //disable ImGui dimming
    //imgui dim default = 0.2f, 0.2f, 0.2f, 0.35f * alpha_mul
    ImU32 color = ImGui::ColorConvertFloat4ToU32({ 0, 0, 0, 0.35f * alpha_mul });

    // Draw list have been trimmed already, hence the explicit recreation of a draw command if missing.
    // FIXME: This is creating complication, might be simpler if we could inject a drawlist in drawdata at a given position and not attempt to manipulate ImDrawCmd order.
    /*ImDrawList* dl = ImGui::GetCurrentWindow()->RootWindowDockTree->DrawList;
    dl->ChannelsMerge();
    //if (dl->CmdBuffer.Size == 0)
        dl->AddDrawCmd();
    dl->PushClipRectFullScreen();
    //dl->PushClipRect(rect.Min - ImVec2(1, 1), rect.Max + ImVec2(1, 1), false); // FIXME: Need to stricty ensure ImDrawCmd are not merged (ElemCount==6 checks below will verify that)
    dl->AddRectFilled(rect.Min, rect.Max, color);
    ImDrawCmd cmd = dl->CmdBuffer.back();
    IM_ASSERT(cmd.ElemCount == 6);
    dl->CmdBuffer.pop_back();
    dl->CmdBuffer.push_front(cmd);
    dl->AddDrawCmd(); // We need to create a command as CmdBuffer.back().IdxOffset won't be correct if we append to same command.
    dl->PopClipRect();*/

    /*ImDrawList* dl = ImGui::GetCurrentWindow()->RootWindowDockTree->DrawList;
    dl->PushClipRectFullScreen();
    dl->AddRectFilled(rect.Min, rect.Max, color);
    dl->PopClipRect();*/

    ImDrawList* dl = ImGui::GetWindowDrawList();
    dl->PushClipRectFullScreen();
    const ImRect& wr = ImGui::GetCurrentWindow()->Rect();
    dl->AddRectFilled(rect.Min, { rect.Max.x, wr.Min.y }, color);
    dl->AddRectFilled({ rect.Min.x, wr.Min.y }, { wr.Min.x, wr.Max.y }, color);
    dl->AddRectFilled({ wr.Max.x, wr.Min.y }, { rect.Max.x, wr.Max.y }, color);
    dl->AddRectFilled({ rect.Min.x, wr.Max.y }, rect.Max, color);
    float r = ImGui::GetCurrentWindow()->WindowRounding;
    if (r)
    {
        dl->AddRectFilled(wr.Min, { wr.Min.x + r, wr.Min.y + r }, color);
        dl->AddRectFilled({ wr.Min.x, wr.Max.y - r }, { wr.Min.x + r, wr.Max.y }, color);
        dl->AddRectFilled({ wr.Max.x - r, wr.Min.y }, { wr.Max.x, wr.Min.y + r }, color);
        dl->AddRectFilled({ wr.Max.x - r, wr.Max.y - r }, wr.Max, color);

        ImU32 bg = ImGui::GetColorU32(ImGui::GetStyleColorVec4(ImGuiCol_PopupBg));
        dl->PathArcToFast({ wr.Min.x + r, wr.Min.y + r }, r, 6, 9);
        dl->PathLineTo({ wr.Min.x + r, wr.Min.y + r });
        dl->PathFillConvex(bg);
        dl->PathArcToFast({ wr.Min.x + r, wr.Max.y - r }, r, 3, 6);
        dl->PathLineTo({ wr.Min.x + r, wr.Max.y - r });
        dl->PathFillConvex(bg);
        dl->PathArcToFast({ wr.Max.x - r, wr.Min.y + r }, r, 9, 12);
        dl->PathLineTo({ wr.Max.x - r, wr.Min.y + r });
        dl->PathFillConvex(bg);
        dl->PathArcToFast({ wr.Max.x - r, wr.Max.y - r }, r, 0, 3);
        dl->PathLineTo({ wr.Max.x - r, wr.Max.y - r });
        dl->PathFillConvex(bg);
    }
    dl->PopClipRect();
}

inline void RenderFilledWindowCorners(ImDrawFlags fl)
{
    ImDrawList* dl = ImGui::GetWindowDrawList();
    ImGuiWindow* win = ImGui::GetCurrentWindow();
    ImVec2 pos = ImGui::GetWindowPos();
    ImVec2 size = ImGui::GetWindowSize();
    float r = (win->Flags & ImGuiWindowFlags_Popup) && !(win->Flags & ImGuiWindowFlags_Modal) ?
        ImGui::GetStyle().PopupRounding : ImGui::GetStyle().WindowRounding;
    ImVec2 pad = ImGui::GetStyle().WindowPadding;
    //GetWindowBgColorIdx is not accessible
    ImU32 col = ImGui::GetColorU32((win->Flags & ImGuiWindowFlags_Popup) ? ImGuiCol_PopupBg : ImGuiCol_WindowBg);

    ImGui::PushClipRect(pos, { pos.x + size.x, pos.y + size.y }, false);

    if (fl & ImDrawFlags_RoundCornersBottomLeft)
        dl->AddRectFilled({ pos.x, pos.y + size.y - r }, { pos.x + r, pos.y + size.y },    col);
    if (fl & ImDrawFlags_RoundCornersBottomRight)
        dl->AddRectFilled({ pos.x + size.x - r, pos.y + size.y - r }, { pos.x + size.x, pos.y + size.y }, col);
    if (fl & ImDrawFlags_RoundCornersTopLeft)
        dl->AddRectFilled(pos, { pos.x + r, pos.y + r }, col);
    if (fl & ImDrawFlags_RoundCornersTopRight)
        dl->AddRectFilled({ pos.x + size.x - r, pos.y }, { pos.x + size.x, pos.y + r }, col);

    ImGui::PopClipRect();
}

inline std::string FormatFallback(std::string_view fmt)
{
    return std::string(fmt);
}

template <class A1, class... A>
std::string FormatFallback(std::string_view fmt, A1&& arg, A&&... args)
{
    //todo
    std::string s;
    for (size_t i = 0; i < fmt.size(); ++i)
    {
        if (fmt[i] == '{') {
            if (i + 1 == fmt.size())
                break;
            if (fmt[i + 1] == '{') {
                s += '{';
                ++i;
            }
            else {
                auto j = fmt.find('}', i + 1);
                if (j == std::string::npos)
                    break;
                if constexpr (std::is_same_v<std::decay_t<A1>, std::string>)
                    s += arg;
                else if constexpr (std::is_same_v<std::decay_t<A1>, const char*> ||
                                    std::is_same_v<std::decay_t<A1>, char*>)
                    s += arg;
                else if constexpr (std::is_same_v<std::decay_t<A1>, char>)
                    s += arg;
                else
                    s += std::to_string(arg);
                return s + FormatFallback(fmt.substr(j + 1), args...);
            }
        }
        else
            s += fmt[i];
    }
    return s;
}

#ifdef IMRAD_WITH_FMT
template <class... A>
std::string Format(std::string_view fmt, A&&... args)
{
    return fmt::format(fmt, std::forward<A>(args)...);
}

#elif __cplusplus >= 202002L && __has_include(<format>)

//only support format_string version for compile time checks
template <class... A>
std::string Format(std::format_string<A...> fmt, A&&... args)
{
    return std::format(fmt, std::forward<A>(args)...);
}

#else

template <class... A>
std::string Format(std::string_view fmt, A&&... args)
{
    return FormatFallback(fmt, std::forward<A>(args)...);
}
#endif

#if (defined (IMRAD_WITH_GLFW) || defined(ANDROID)) && defined(IMRAD_WITH_STB)
// Simple helper function to load an image into a OpenGL texture with common settings
// https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples
inline Texture LoadTextureFromFile(
    std::string_view filename,
    int minFilter = GL_LINEAR,
    int magFilter = GL_LINEAR,
    int wrapS = GL_CLAMP_TO_EDGE, // This is required on WebGL for non power-of-two textures
    int wrapT = GL_CLAMP_TO_EDGE // Same
) {
    // Load from file
    Texture tex;
    unsigned char* image_data = nullptr;
#ifdef ANDROID
    unsigned char* buffer;
    int len = GetAssetData(filename.c_str(), &buffer);
    image_data = stbi_load_from_memory(buffer, len, &tex.w, &tex.h, NULL, 4);
#else
    std::string tmp(filename);
    image_data = stbi_load(tmp.c_str(), &tex.w, &tex.h, NULL, 4);
#endif
    if (image_data == NULL)
        return {};

    // Create a OpenGL texture identifier
    GLuint image_texture;
    glGenTextures(1, &image_texture);
    tex.id = (ImTextureID)(intptr_t)image_texture;
    glBindTexture(GL_TEXTURE_2D, image_texture);

    // Setup filtering parameters for display
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, minFilter);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, magFilter);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrapS);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrapT);

    // Upload pixels into texture
#if defined(GL_UNPACK_ROW_LENGTH) && !defined(__EMSCRIPTEN__)
    glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
#endif
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, tex.w, tex.h, 0, GL_RGBA, GL_UNSIGNED_BYTE, image_data);
    stbi_image_free(image_data);

    return tex;
}
#else
Texture LoadTextureFromFile(std::string_view filename);
#endif

inline std::filesystem::path u8path(std::string_view s)
{
#if __cplusplus >= 202002L
    return std::filesystem::path((const char8_t*)s.data(), (const char8_t*)s.data() + s.size());
#else
    return std::filesystem::u8path(s);
#endif
}

inline std::string u8string(const std::filesystem::path& p)
{
#if __cplusplus >= 202002L
    return std::string((const char*)p.u8string().data());
#else
    return p.u8string();
#endif
}

//For debugging pruposes
inline void SaveStyle(std::string_view spath, const ImGuiStyle* src = nullptr, const std::map<std::string, std::string>& extra = {})
{
    const ImGuiStyle* style = src ? src : &ImGui::GetStyle();
    auto stylePath = u8path(spath);
    std::ofstream fout(stylePath);
    if (!fout)
        throw std::runtime_error("can't write '" + stylePath.string() + "'");

    fout << "[colors]\n";
    for (int i = 0; i < ImGuiCol_COUNT; ++i) {
        fout << ImGui::GetStyleColorName(i) << " = ";
        const auto& clr = style->Colors[i];
        fout << int(clr.x * 255) << " " << int(clr.y * 255) << " "
            << int(clr.z * 255) << " " << int(clr.w * 255) << "\n";
    }

    fout << "\n[variables]\n";
#define WRITE_FLT(a) fout << #a " = " << style->a << "\n"
#define WRITE_VEC(a) fout << #a " = " << style->a.x << " " << style->a.y << "\n"

    WRITE_FLT(Alpha);
    WRITE_FLT(DisabledAlpha);
    WRITE_VEC(WindowPadding);
    WRITE_FLT(WindowRounding);
    WRITE_FLT(WindowBorderSize);
    WRITE_VEC(WindowMinSize);
    WRITE_VEC(WindowTitleAlign);
    WRITE_FLT(ChildRounding);
    WRITE_FLT(ChildBorderSize);
    WRITE_FLT(PopupRounding);
    WRITE_FLT(PopupBorderSize);
    WRITE_VEC(FramePadding);
    WRITE_FLT(FrameRounding);
    WRITE_FLT(FrameBorderSize);
    WRITE_VEC(ItemSpacing);
    WRITE_VEC(ItemInnerSpacing);
    WRITE_VEC(CellPadding);
    WRITE_FLT(IndentSpacing);
    WRITE_FLT(ScrollbarSize);
    WRITE_FLT(ScrollbarRounding);
    WRITE_FLT(TabRounding);
    WRITE_FLT(TabBorderSize);
#undef WRITE_FLT
#undef WRITE_VEC

    fout << "\n[fonts]\n";
    fout << "Default = \"Roboto-Medium.ttf\" size 20\n";

    std::string lastSection;
    for (const auto& kv : extra)
    {
        size_t i = kv.first.find_last_of('.');
        if (i == std::string::npos)
            continue;
        if (kv.first.substr(0, i) != lastSection) {
            lastSection = kv.first.substr(0, i);
            fout << "\n[" << lastSection << "]\n";
        }
        fout << kv.first.substr(i + 1) << " = " << kv.second << "\n";
    }
}

//This function can be used in your code to load style and fonts from the INI file
//It is also used by ImRAD when switching themes
inline void LoadStyle(std::string_view spath, float fontScaling = 1, ImGuiStyle* dst = nullptr, std::map<std::string, ImFont*>* fontMap = nullptr, std::map<std::string, std::string>* extra = nullptr)
{
    ImGuiStyle* style = dst ? dst : &ImGui::GetStyle();
    *style = ImGuiStyle();
    auto& io = ImGui::GetIO();

    auto stylePath = u8path(spath);
    std::ifstream fin(stylePath);
    if (!fin)
        throw std::runtime_error("Can't read " + stylePath.string());
    std::string line;
    std::string cat;
    int lastClr = -1;
    std::string lastFont;
    while (std::getline(fin, line))
    {
        if (line.empty() || line[0] == ';' || line[0] == '#')
            continue;
        else if (line[0] == '[' && line.back() == ']')
            cat = line.substr(1, line.size() - 2);
        else
        {
            size_t i1 = line.find_first_not_of("=\t ", 0);
            size_t i2 = line.find_first_of("=\t ", i1);
            if (i1 == std::string::npos || i2 == std::string::npos)
                continue;
            std::string key = line.substr(i1, i2 - i1);
            i1 = line.find_first_not_of("=\t ", i2);
            std::istringstream is(line.substr(i1));

            if (cat == "colors")
            {
                for (int i = lastClr + 1; i != lastClr; i = (i + 1) % ImGuiCol_COUNT)
                    if (key == ImGui::GetStyleColorName(i)) {
                        lastClr = i;
                        int r, g, b, a;
                        is >> r >> g >> b >> a;
                        style->Colors[i].x = r / 255.f;
                        style->Colors[i].y = g / 255.f;
                        style->Colors[i].z = b / 255.f;
                        style->Colors[i].w = a / 255.f;
                        break;
                    }
            }
            else if (cat == "variables")
            {
#define READ_FLT(a) if (key == #a) is >> style->a;
#define READ_VEC(a) if (key == #a) is >> style->a.x >> style->a.y;

                READ_FLT(Alpha);
                READ_FLT(DisabledAlpha);
                READ_VEC(WindowPadding);
                READ_FLT(WindowRounding);
                READ_FLT(WindowBorderSize);
                READ_VEC(WindowMinSize);
                READ_VEC(WindowTitleAlign);
                READ_FLT(ChildRounding);
                READ_FLT(ChildBorderSize);
                READ_FLT(PopupRounding);
                READ_FLT(PopupBorderSize);
                READ_VEC(FramePadding);
                READ_FLT(FrameRounding);
                READ_FLT(FrameBorderSize);
                READ_VEC(ItemSpacing);
                READ_VEC(ItemInnerSpacing);
                READ_VEC(CellPadding);
                READ_FLT(IndentSpacing);
                READ_FLT(ScrollbarSize);
                READ_FLT(ScrollbarRounding);
                READ_FLT(TabRounding);
                READ_FLT(TabBorderSize);
#undef READ_FLT
#undef READ_VEC
            }
            else if (cat == "fonts")
            {
                std::string fname;
                float size = 20;
                ImVec2 goffset;
                bool hasRange = false;
                static std::vector<std::unique_ptr<ImWchar[]>> rngs;

                is >> std::quoted(fname);
                auto fpath = u8path(fname);
#ifndef ANDROID
                if (fpath.is_relative())
                    fpath = stylePath.parent_path() / fpath;
#endif
                std::string tmp;
                while (is >> tmp)
                {
                    if (tmp == "size")
                        is >> size;
                    else if (tmp == "range") {
                        hasRange = true;
                        //needs to outlive this function
                        rngs.push_back(std::unique_ptr<ImWchar[]>(new ImWchar[3]));
                        is >> rngs.back()[0] >> rngs.back()[1];
                        rngs.back()[2] = 0;
                    }
                    else if (tmp == "goffset") {
                        is >> goffset.x >> goffset.y;
                    }
                }

                ImFontConfig cfg;
                strncpy(cfg.Name, key.c_str(), sizeof(cfg.Name));
                cfg.Name[sizeof(cfg.Name) - 1] = '\0';
                cfg.MergeMode = key == lastFont;
                cfg.GlyphRanges = hasRange ? rngs.back().get() : nullptr;
                cfg.GlyphOffset = { goffset.x * fontScaling, goffset.y * fontScaling };
#ifdef ANDROID
                void* font_data;
                int font_data_size = GetAssetData(u8string(fpath).c_str(), &font_data);
                ImFont* fnt = io.Fonts->AddFontFromMemoryTTF(font_data, font_data_size, size * fontScaling);
#else
                if (!std::ifstream(fpath))
                    throw std::runtime_error("Can't read '" + u8string(fpath) + "'");
                ImFont* fnt = io.Fonts->AddFontFromFileTTF(u8string(fpath).c_str(), size * fontScaling, &cfg);
#endif
                if (!fnt)
                    throw std::runtime_error("Can't load " + u8string(fpath));
                if (!cfg.MergeMode && fontMap)
                    (*fontMap)[lastFont == "" ? "" : key] = fnt;

                lastFont = key;
            }
            else if (extra)
            {
                (*extra)[cat + "." + key] = is.str();
            }
        }
    }
    if (fontMap && !(*fontMap).count(""))
        (*fontMap)[""] = io.Fonts->AddFontDefault();
}

//This function will be called from the generated code when alternate font is used
inline ImFont* GetFontByName(std::string_view name)
{
    if (name == "")
        return ImGui::GetDefaultFont();

    const auto& io = ImGui::GetIO();
    for (const auto& cfg : io.Fonts->ConfigData) {
        if (cfg.MergeMode)
            continue;
        if (name == cfg.Name)
            return cfg.DstFont;
    }
    return nullptr;
}

}