ImGuiConsole.cc

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#include "ImGuiConsole.hh"
 
#include "ImGuiCpp.hh"
#include "ImGuiManager.hh"
#include "ImGuiUtils.hh"
 
#include "BooleanSetting.hh"
#include "CliComm.hh"
#include "Completer.hh"
#include "FileContext.hh"
#include "FileException.hh"
#include "FileOperations.hh"
#include "GlobalCommandController.hh"
#include "Interpreter.hh"
#include "Reactor.hh"
#include "TclParser.hh"
#include "Version.hh"
 
#include "narrow.hh"
#include "strCat.hh"
#include "utf8_unchecked.hh"
#include "xrange.hh"
 
#include <imgui.h>
#include <imgui_internal.h>  // Hack: see below
#include <imgui_stdlib.h>
 
#include <fstream>
 
namespace openmsx {
 
using namespace std::literals;
 
static constexpr std::string_view PROMPT_NEW  = "> ";
static constexpr std::string_view PROMPT_CONT = "| ";
static constexpr std::string_view PROMPT_BUSY = "*busy*";
 
ImGuiConsole::ImGuiConsole(ImGuiManager& manager_)
        : ImGuiPart(manager_)
        , consoleSetting(
                manager.getReactor().getCommandController(), "console",
                "turns console display on/off", false, Setting::Save::NO)
        , history(1000)
        , lines(1000)
        , prompt(PROMPT_NEW)
{
        loadHistory();
 
        Completer::setOutput(this);
        manager.getInterpreter().setOutput(this);
        consoleSetting.attach(*this);
 
        const auto& fullVersion = Version::full();
        print(fullVersion);
        print(std::string(fullVersion.size(), '-'));
        print("\n"
              "General information about openMSX is available at http://openmsx.org.\n"
              "\n"
              "Type 'help' to see a list of available commands.\n"
              "Or read the Console Command Reference in the manual.\n"
              "\n");
}
 
ImGuiConsole::~ImGuiConsole()
{
        consoleSetting.detach(*this);
}
 
void ImGuiConsole::save(ImGuiTextBuffer& buf)
{
        savePersistent(buf, *this, persistentElements);
}
 
void ImGuiConsole::loadLine(std::string_view name, zstring_view value)
{
        loadOnePersistent(name, value, *this, persistentElements);
}
 
void ImGuiConsole::print(std::string_view text, imColor color)
{
        do {
                auto pos = text.find('\n');
                newLineConsole(ConsoleLine(std::string(text.substr(0, pos)), color));
                if (pos == std::string_view::npos) break;
                text.remove_prefix(pos + 1); // skip newline
        } while (!text.empty());
}
 
void ImGuiConsole::newLineConsole(ConsoleLine line)
{
        auto addLine = [&](ConsoleLine&& l) {
                if (lines.full()) lines.pop_front();
                lines.push_back(std::move(l));
        };
 
        if (wrap) {
                do {
                        auto rest = line.splitAtColumn(columns);
                        addLine(std::move(line));
                        line = std::move(rest);
                } while (!line.str().empty());
        } else {
                addLine(std::move(line));
        }
 
        scrollToBottom = true;
}
 
static void drawLine(const ConsoleLine& line)
{
        auto n = line.numChunks();
        for (auto i : xrange(n)) {
                im::StyleColor(ImGuiCol_Text, getColor(line.chunkColor(i)), [&]{
                        ImGui::TextUnformatted(line.chunkText(i));
                        if (i != (n - 1)) ImGui::SameLine(0.0f, 0.0f);
                });
        }
}
 
void ImGuiConsole::paint(MSXMotherBoard* /*motherBoard*/)
{
        bool reclaimFocus = show && !wasShown; // window appears
        wasShown = show;
        if (!show) return;
 
        ImGui::SetNextWindowSize(ImVec2(520, 600), ImGuiCond_FirstUseEver);
        im::Window("Console", &show, [&]{
                im::ScopedFont sf(manager.fontMono);
 
                // Reserve enough left-over height for 1 separator + 1 input text
                const auto& style = ImGui::GetStyle();
                const float footerHeightToReserve = style.ItemSpacing.y +
                                                ImGui::GetFrameHeightWithSpacing();
 
                bool scrollUp   = ImGui::Shortcut(ImGuiKey_PageUp);
                bool scrollDown = ImGui::Shortcut(ImGuiKey_PageDown);
                im::Child("ScrollingRegion", ImVec2(0, -footerHeightToReserve), 0,
                          ImGuiWindowFlags_HorizontalScrollbar, [&]{
                        im::PopupContextWindow([&]{
                                if (ImGui::Selectable("Clear")) {
                                        lines.clear();
                                }
                                ImGui::Checkbox("Wrap (new) output", &wrap);
                        });
 
                        im::StyleVar(ImGuiStyleVar_ItemSpacing, ImVec2(4, 1), [&]{ // Tighten spacing
                                im::ListClipper(lines.size(), [&](int i) {
                                        drawLine(lines[i]);
                                });
                        });
 
                        // Keep up at the bottom of the scroll region if we were already
                        // at the bottom at the beginning of the frame.
                        if (scrollToBottom || (ImGui::GetScrollY() >= ImGui::GetScrollMaxY())) {
                                scrollToBottom = false;
                                ImGui::SetScrollHereY(1.0f);
                        }
 
                        auto scrollDelta = ImGui::GetWindowHeight() * 0.5f;
                        if (scrollUp) {
                                ImGui::SetScrollY(std::max(ImGui::GetScrollY() - scrollDelta, 0.0f));
                        }
                        if (scrollDown) {
                                ImGui::SetScrollY(std::min(ImGui::GetScrollY() + scrollDelta, ImGui::GetScrollMaxY()));
                        }
 
                        // recalculate the number of columns
                        auto width = ImGui::GetContentRegionMax().x;
                        auto charWidth = ImGui::CalcTextSize("M"sv).x;
                        columns = narrow_cast<unsigned>(width / charWidth);
                });
                ImGui::Separator();
 
                // Command-line
                ImGui::AlignTextToFramePadding();
                ImGui::TextUnformatted(prompt);
                ImGui::SameLine(0.0f, 0.0f);
 
                ImGui::SetNextItemWidth(-FLT_MIN); // full window width
                 // Hack: see below
                 auto cursorScrnPos = ImGui::GetCursorScreenPos();
                 auto itemWidth = ImGui::CalcItemWidth();
 
                ImGuiInputTextFlags flags = ImGuiInputTextFlags_EnterReturnsTrue |
                                        ImGuiInputTextFlags_EscapeClearsAll |
                                        ImGuiInputTextFlags_CallbackEdit |
                                        ImGuiInputTextFlags_CallbackCompletion |
                                        ImGuiInputTextFlags_CallbackHistory;
                bool enter = false;
                im::StyleColor(ImGuiCol_Text, 0x00000000, [&]{ // transparent, see HACK below
                        enter = ImGui::InputTextWithHint("##Input", "enter command", &inputBuf, flags, &textEditCallbackStub, this);
                });
                if (enter && (prompt != PROMPT_BUSY)) {
                        // print command in output buffer, with prompt prepended
                        ConsoleLine cmdLine(prompt);
                        cmdLine.addLine(coloredInputBuf);
                        newLineConsole(std::move(cmdLine));
 
                        // append (partial) command to a possibly multi-line command
                        strAppend(commandBuffer, inputBuf, '\n');
 
                        putHistory(std::move(inputBuf));
                        saveHistory(); // save at this point already, so that we don't lose history in case of a crash
                        inputBuf.clear();
                        coloredInputBuf.clear();
                        historyPos = -1;
                        historyBackupLine.clear();
 
                        auto& commandController = manager.getReactor().getGlobalCommandController();
                        if (commandController.isComplete(commandBuffer)) {
                                // Normally the busy prompt is NOT shown (not even briefly
                                // because the screen is not redrawn), though for some commands
                                // that potentially take a long time to execute, we explicitly
                                // do redraw.
                                prompt = PROMPT_BUSY;
 
                                manager.executeDelayed(TclObject(commandBuffer),
                                        [this](const TclObject& result) {
                                                if (const auto& s = result.getString(); !s.empty()) {
                                                        this->print(s);
                                                }
                                                prompt = PROMPT_NEW;
                                        },
                                        [this](const std::string& error) {
                                                this->print(error, imColor::ERROR);
                                                prompt = PROMPT_NEW;
                                        });
                                commandBuffer.clear();
                        } else {
                                prompt = PROMPT_CONT;
                        }
                        reclaimFocus = true;
                }
                ImGui::SetItemDefaultFocus();
 
                if (reclaimFocus ||
                (ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows) &&
                !ImGui::IsPopupOpen(nullptr, ImGuiPopupFlags_AnyPopupId) &&
                !ImGui::IsAnyItemActive() && !ImGui::IsMouseClicked(0) && !ImGui::IsMouseClicked(1))) {
                        ImGui::SetKeyboardFocusHere(-1); // focus the InputText widget
                }
 
                 // Hack: currently ImGui::InputText() does not support colored text.
                 // Though there are plans to extend this. See:
                 //     https://github.com/ocornut/imgui/pull/3130
                 //     https://github.com/ocornut/imgui/issues/902
                 // To work around this limitation, we use ImGui::InputText() as-is,
                 // but then overdraw the text using the correct colors. This works,
                 // but it's fragile because it depends on some internal implementation
                 // details. More specifically: the scroll-position. And obtaining this
                 // information required stuff from <imgui_internal.h>.
                 const auto* font = ImGui::GetFont();
                 auto fontSize = ImGui::GetFontSize();
                 gl::vec2 frameSize(itemWidth, fontSize + style.FramePadding.y * 2.0f);
                 gl::vec2 topLeft = cursorScrnPos;
                 gl::vec2 bottomRight = topLeft + frameSize;
                 gl::vec2 drawPos = topLeft + gl::vec2(style.FramePadding);
                 ImVec4 clipRect = gl::vec4(topLeft, bottomRight);
                 auto* drawList = ImGui::GetWindowDrawList();
                 auto charWidth = ImGui::GetFont()->GetCharAdvance('A'); // assumes fixed-width font
                 if (ImGui::IsItemActive()) {
                        auto id = ImGui::GetID("##Input");
                        if (const auto* state = ImGui::GetInputTextState(id)) { // Internal API !!!
                                // adjust for scroll
                                drawPos.x -= state->ScrollX;
                                // redraw cursor (it was drawn transparent before)
                                bool cursorIsVisible = (state->CursorAnim <= 0.0f) || ImFmod(state->CursorAnim, 1.20f) <= 0.80f;
                                if (cursorIsVisible) {
                                        // This assumes a single line and fixed-width font
                                        gl::vec2 cursorOffset(float(state->GetCursorPos()) * charWidth, 0.0f);
                                        gl::vec2 cursorScreenPos = ImTrunc(drawPos + cursorOffset);
                                        ImRect cursorScreenRect(cursorScreenPos.x, cursorScreenPos.y - 0.5f, cursorScreenPos.x + 1.0f, cursorScreenPos.y + fontSize - 1.5f);
                                        if (cursorScreenRect.Overlaps(clipRect)) {
                                                drawList->AddLine(cursorScreenRect.Min, cursorScreenRect.GetBL(), getColor(imColor::TEXT));
                                        }
                                }
                        }
                 }
                 for (auto i : xrange(coloredInputBuf.numChunks())) {
                        auto text = coloredInputBuf.chunkText(i);
                        auto rgba = getColor(coloredInputBuf.chunkColor(i));
                        const char* begin = text.data();
                        const char* end = begin + text.size();
                        drawList->AddText(font, fontSize, drawPos, rgba, begin, end, 0.0f, &clipRect);
                    // avoid ImGui::CalcTextSize(): it's off-by-one for sizes >= 256 pixels
                    drawPos.x += charWidth * float(utf8::unchecked::distance(begin, end));
                 }
        });
}
 
int ImGuiConsole::textEditCallbackStub(ImGuiInputTextCallbackData* data)
{
        auto* console = static_cast<ImGuiConsole*>(data->UserData);
        return console->textEditCallback(data);
}
 
int ImGuiConsole::textEditCallback(ImGuiInputTextCallbackData* data)
{
        switch (data->EventFlag) {
        case ImGuiInputTextFlags_CallbackCompletion: {
                std::string_view oldLine{data->Buf, narrow<size_t>(data->BufTextLen)};
                std::string_view front = utf8::unchecked::substr(oldLine, 0, data->CursorPos);
                std::string_view back  = utf8::unchecked::substr(oldLine, data->CursorPos);
 
                auto& commandController = manager.getReactor().getGlobalCommandController();
                std::string newFront = commandController.tabCompletion(front);
                historyBackupLine = strCat(std::move(newFront), back);
                historyPos = -1;
 
                data->DeleteChars(0, data->BufTextLen);
                data->InsertChars(0, historyBackupLine.c_str());
 
                colorize(historyBackupLine);
                break;
        }
        case ImGuiInputTextFlags_CallbackHistory: {
                bool match = false;
                if (data->EventKey == ImGuiKey_UpArrow) {
                        while (!match && (historyPos < narrow<int>(history.size() - 1))) {
                                ++historyPos;
                                match = history[historyPos].starts_with(historyBackupLine);
                        }
                } else if ((data->EventKey == ImGuiKey_DownArrow) && (historyPos != -1)) {
                        while (!match) {
                                if (--historyPos == -1) break;
                                match = history[historyPos].starts_with(historyBackupLine);
                        }
                }
                if (match || (historyPos == -1)) {
                        const auto& historyStr = (historyPos >= 0) ? history[historyPos] : historyBackupLine;
                        data->DeleteChars(0, data->BufTextLen);
                        data->InsertChars(0, historyStr.c_str());
                        colorize(std::string_view{data->Buf, narrow<size_t>(data->BufTextLen)});
                }
                break;
        }
        case ImGuiInputTextFlags_CallbackEdit: {
                historyBackupLine.assign(data->Buf, narrow<size_t>(data->BufTextLen));
                historyPos = -1;
                colorize(historyBackupLine);
                break;
        }
        }
        return 0;
}
 
void ImGuiConsole::colorize(std::string_view line)
{
        TclParser parser = manager.getInterpreter().parse(line);
        const auto& colors = parser.getColors();
        assert(colors.size() == line.size());
 
        coloredInputBuf.clear();
        size_t pos = 0;
        while (pos != colors.size()) {
                char col = colors[pos];
                size_t pos2 = pos++;
                while ((pos != colors.size()) && (colors[pos] == col)) {
                        ++pos;
                }
                imColor color = [&] {
                        switch (col) {
                        using enum imColor;
                        case 'E': return ERROR;
                        case 'c': return COMMENT;
                        case 'v': return VARIABLE;
                        case 'l': return LITERAL;
                        case 'p': return PROC;
                        case 'o': return OPERATOR;
                        default:  return TEXT; // other
                        }
                }();
                coloredInputBuf.addChunk(line.substr(pos2, pos - pos2), color);
        }
}
 
void ImGuiConsole::putHistory(std::string command)
{
        if (command.empty()) return;
        if (!history.empty() && (history.front() == command)) {
                return;
        }
        if (history.full()) history.pop_back();
        history.push_front(std::move(command));
}
 
void ImGuiConsole::saveHistory()
{
        try {
                std::ofstream outputFile;
                FileOperations::openOfStream(outputFile,
                        userFileContext("console").resolveCreate("history.txt"));
                if (!outputFile) {
                        throw FileException("Error while saving the console history.");
                }
                for (const auto& s : view::reverse(history)) {
                        outputFile << s << '\n';
                }
        } catch (FileException& e) {
                manager.getCliComm().printWarning(e.getMessage());
        }
}
 
void ImGuiConsole::loadHistory()
{
        try {
                std::ifstream inputFile(
                        userFileContext("console").resolveCreate("history.txt"));
                std::string line;
                while (inputFile) {
                        getline(inputFile, line);
                        putHistory(line);
                }
        } catch (FileException&) {
                // Error while loading the console history, ignore
        }
}
 
void ImGuiConsole::output(std::string_view text)
{
        print(text);
}
 
unsigned ImGuiConsole::getOutputColumns() const
{
        return columns;
}
 
void ImGuiConsole::update(const Setting& /*setting*/) noexcept
{
        show = consoleSetting.getBoolean();
        if (!show) {
                // Close the console via the 'console' setting.  Typically this
                // means via the F10 hotkey (or possibly by typing 'set console
                // off' in the console).
                //
                // Give focus to the main openMSX window.
                //
                // This makes the following scenario work:
                // * You were controlling the MSX, e.g. playing a game.
                // * You press F10 to open the console.
                // * You type a command (e.g. swap a game disk, for some people
                //   the console is still more convenient and/or faster than the
                //   new media menu).
                // * You press F10 again to close the console
                // * At this point the focus should go back to the main openMSX
                //   window (so that MSX input works).
                SDL_SetWindowInputFocus(SDL_GetWindowFromID(WindowEvent::getMainWindowId()));
                ImGui::SetWindowFocus(nullptr);
        }
}
 
} // namespace openmsx