Widgets.h

#pragma once
 
#include "LkEngine/Core/Core.h"
#include "LkEngine/Core/LObject/Enum.h"
#include "LkEngine/Core/Delegate/Delegate.h"
#include "LkEngine/Editor/EditorCore.h"
#include "LkEngine/Renderer/UI/UICore.h"
#include "LkEngine/Renderer/UI/Property.h"
#include "LkEngine/Renderer/UI/TreeNode.h"
#include "LkEngine/Renderer/UI/Table.h"
 
#include <imgui/imgui.h>
#include <imgui/imgui_internal.h>
 
 
namespace LkEngine::UI {
 
    class Widget
    {
    public:
        template<uint32_t BufSize = 256, float InputBarWidth = 220.0f, typename StringType>
        static bool SearchWidget(StringType& SearchStr, 
                                 const char* Hint = "Search...", 
                                 bool* GrabFocus = nullptr)
        {
            ImGui::SetCursorPosY(ImGui::GetCursorPosY() + 1.0f);
 
            bool Modified = false;
            bool Searching = false;
 
            const float AreaPosX = ImGui::GetCursorPosX();
            const float FramePaddingX = ImGui::GetStyle().FramePadding.x;
            const float FramePaddingY = ImGui::GetStyle().FramePadding.y;
 
            /* Set frame rounding and padding styles. */
            ImGui::PushStyleVar(ImGuiStyleVar_FrameRounding, 3.0f);
            ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(28.0f, FramePaddingY));
 
            ImGui::SameLine();
            ImGui::SetNextItemAllowOverlap();
            ImGui::SetNextItemWidth(InputBarWidth);
 
            if constexpr (std::is_same_v<StringType, std::string>)
            {
                char SearchBuf[BufSize + 1]{};
                strncpy(SearchBuf, SearchStr.c_str(), BufSize);
 
                if (ImGui::InputText("##Search", SearchBuf, BufSize))
                {
                    SearchStr = SearchBuf;
                    Modified = true;
                }
                else if (ImGui::IsItemDeactivatedAfterEdit())
                {
                    SearchStr = SearchBuf;
                    Modified = true;
                }
 
                Searching = (SearchBuf[0] != '\0');
            }
            else
            {
                static_assert(std::is_same_v<decltype(&SearchStr[0]), char*>, "SearchStr parameter must be std::string& or char*");
                if (ImGui::InputText("##Search", SearchStr, BufSize))
                {
                    Modified = true;
                }
                else if (ImGui::IsItemDeactivatedAfterEdit())
                {
                    Modified = true;
                }
 
                Searching = SearchStr[0] != '\0';
            }
 
            LK_UI_DEBUG_BOUNDING_BOX(RGBA32::NiceBlue);
 
            const ImVec2 InputBarPosStart = ImGui::GetItemRectMin();
            const ImVec2 InputBarPosEnd = ImGui::GetItemRectMax();
 
            /* Size of the search text input bar. */
            const ImVec2 InputBarSize(
                InputBarPosEnd.x - InputBarPosStart.x, 
                InputBarPosEnd.y - InputBarPosStart.y
            );
 
            /* Handle focus grabbing. */
            if (GrabFocus && *GrabFocus)
            {
                if (ImGui::IsWindowFocused(ImGuiFocusedFlags_RootAndChildWindows) 
                    && !ImGui::IsAnyItemActive() 
                    && !ImGui::IsMouseClicked(0))
                {
                    ImGui::SetKeyboardFocusHere(-1);
                }
 
                if (ImGui::IsItemFocused())
                {
                    *GrabFocus = false;
                    LK_CORE_DEBUG_TAG("SearchWidget", "Setting GrabFocus to false");
                }
            }
 
            /* Draw activity outline. */
            const ImRect ItemRect(ImGui::GetItemRectMin(), ImGui::GetItemRectMax());
            ImGui::RenderNavCursor(ItemRect, ImGui::GetID("##Search"));
 
            ImGui::SameLine(AreaPosX + 5.0f);
 
            /***********************************
             * Search and clear icon. 
             ***********************************/
            ImGui::BeginGroup();
            const ImVec2 IconSize(ImGui::GetTextLineHeight(), ImGui::GetTextLineHeight());
            LK_CORE_ASSERT((IconSize.x > 0) && (IconSize.y > 0));
 
            /* Search Icon. */
            {
                const float IconYOffset = FramePaddingY - 3.0f;
                ImGui::SetCursorPosY(ImGui::GetCursorPosY() + IconYOffset);
                UI::Image(
                    FEditorResources::SearchIcon,    /* Texture ID. */
                    IconSize,                        /* Image Size. */
                    ImVec2(0.0f, 0.0f),              /* UV0. */
                    ImVec2(1.0f, 1.0f),              /* UV1. */
                    ImVec4(1.0f, 1.0f, 1.0f, 0.20f), /* Tint Color. */
                    ImVec4(0.0f, 0.0f, 0.0f, 0.0f)   /* Border Color. */
                );
                ImGui::SetCursorPosY(ImGui::GetCursorPosY() - IconYOffset);
 
                /* Display the hint text if not searching. */
                if (!Searching)
                {
                    ImGui::SameLine();
 
                    ImGui::SetCursorPosY(ImGui::GetCursorPosY() - FramePaddingY + 2.0f);
                    ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(0.50f, 0.50f, 0.50f, 1.0f));
                    ImGui::TextUnformatted(Hint);
                    ImGui::PopStyleColor();
                    ImGui::SetCursorPosY(ImGui::GetCursorPosY() + FramePaddingY - 2.0f);
                }
            }
 
            /* Draw the clear button if searching. */
            if (Searching)
            {
                static constexpr float SpacingX = 4.0f;
                const float LineHeight = ImGui::GetItemRectSize().y - (FramePaddingY / 2.0f);
                ImGui::SameLine(0.0f, InputBarSize.x - (2.0f * IconSize.x) - FramePaddingX - SpacingX);
                ImGui::SetCursorPosY(ImGui::GetCursorPosY() + FramePaddingY);
                if (ImGui::InvisibleButton("##Clear", ImVec2(LineHeight, LineHeight)))
                {
                    if constexpr (std::is_same_v<StringType, std::string>)
                    {
                        SearchStr.clear();
                    }
                    else
                    {
                        std::memset(SearchStr, 0, BufSize);
                    }
 
                    Modified = true;
                }
                ImGui::SetCursorPosY(ImGui::GetCursorPosY() - FramePaddingY);
 
                /* Change mouse cursor to arrow if hovering over clear button. */
                if (ImGui::IsItemHovered())
                {
                    ImGui::SetMouseCursor(ImGuiMouseCursor_Arrow);
                    UI::SetTooltip(LK_FMT_LIB::format("StartPos: ({}, {})  EndPos: ({}, {})  InputBarSize: ({}, {})", 
                                               InputBarPosStart.x, InputBarPosStart.y, 
                                               InputBarPosEnd.x, InputBarPosEnd.y,
                                               InputBarSize.x, InputBarSize.y));
                }
 
                /* Clear Icon. */
                UI::DrawButtonImage(
                    FEditorResources::ClearIcon,
                    IM_COL32(150, 150, 150, 200),
                    IM_COL32(170, 170, 170, 255),
                    IM_COL32(160, 160, 160, 150),
                    UI::RectExpanded(UI::GetItemRect(), -1.0f, -1.0f)
                );
            }
 
            LK_UI_DEBUG_BOUNDING_BOX(RGBA32::BrightGreen);
 
            /* Set the cursor to the end of the search bar (text input). */
            ImGui::SetCursorScreenPos(ImVec2(InputBarPosEnd.x, ImGui::GetCursorScreenPos().y));
 
            ImGui::EndGroup();
 
            /* Restore cursor position and styles. */
            ImGui::SetCursorPosY(ImGui::GetCursorPosY() - 1.0f);
            ImGui::PopStyleVar(2);
 
            return Modified;
        }
 
        static bool OptionsButton();
 
    };
 
}