UnicodeKeymap.cc

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#include "UnicodeKeymap.hh"
#include "MSXException.hh"
#include "File.hh"
#include "FileContext.hh"
#include "FileException.hh"
#include "ranges.hh"
#include "stl.hh"
#include "StringOp.hh"
#include <cstring>

using std::string_view;

namespace openmsx {

static unsigned parseHex(string_view str, bool& ok)
{
        if (str.empty()) {
                ok = false;
                return 0;
        }
        unsigned value = 0;
        for (const char c : str) {
                value *= 16;
                if ('0' <= c && c <= '9') {
                        value += c - '0';
                } else if ('A' <= c && c <= 'F') {
                        value += c - 'A' + 10;
                } else if ('a' <= c && c <= 'f') {
                        value += c - 'a' + 10;
                } else {
                        ok = false;
                        return 0;
                }
        }
        ok = true;
        return value;
}

static inline bool isSep(char c)
{
        return c == ','                           // comma
            || c == ' ' || c == '\t' || c == '\r' // whitespace
            || c == '#';                          // comment
}

static void skipSep(string_view& str)
{
        while (!str.empty()) {
                const char c = str.front();
                if (!isSep(c)) break;
                if (c == '#') {
                        // Skip till end of line.
                        while (!str.empty() && str.front() != '\n') str.remove_prefix(1);
                        break;
                }
                str.remove_prefix(1);
        }
}

static string_view nextToken(string_view& str)
{
        skipSep(str);
        auto tokenBegin = str.begin();
        while (!str.empty() && str.front() != '\n' && !isSep(str.front())) {
                // Pop non-separator character.
                str.remove_prefix(1);
        }
        return string_view(&*tokenBegin, str.begin() - tokenBegin);
}


UnicodeKeymap::UnicodeKeymap(string_view keyboardType)
{
        auto filename = systemFileContext().resolve(
                strCat("unicodemaps/unicodemap.", keyboardType));
        try {
                File file(filename);
                auto buf = file.mmap();
                parseUnicodeKeymapfile(
                        string_view(reinterpret_cast<const char*>(buf.data()), buf.size()));
        } catch (FileException&) {
                throw MSXException("Couldn't load unicode keymap file: ", filename);
        }
}

UnicodeKeymap::KeyInfo UnicodeKeymap::get(unsigned unicode) const
{
        auto it = ranges::lower_bound(mapdata, unicode, LessTupleElement<0>());
        return ((it != end(mapdata)) && (it->first == unicode))
                ? it->second : KeyInfo();
}

UnicodeKeymap::KeyInfo UnicodeKeymap::getDeadkey(unsigned n) const
{
        assert(n < NUM_DEAD_KEYS);
        return deadKeys[n];
}

void UnicodeKeymap::parseUnicodeKeymapfile(string_view data)
{
        memset(relevantMods, 0, sizeof(relevantMods));

        while (!data.empty()) {
                if (data.front() == '\n') {
                        // Next line.
                        data.remove_prefix(1);
                }

                string_view token = nextToken(data);
                if (token.empty()) {
                        // Skip empty line.
                        continue;
                }

                // Parse first token: a unicode value or the keyword DEADKEY.
                unsigned unicode = 0;
                unsigned deadKeyIndex = 0;
                bool isDeadKey = StringOp::startsWith(token, "DEADKEY");
                if (isDeadKey) {
                        token.remove_prefix(strlen("DEADKEY"));
                        if (token.empty()) {
                                // The normal keywords are
                                //    DEADKEY1  DEADKEY2  DEADKEY3
                                // but for backwards compatibility also still recognize
                                //    DEADKEY
                        } else {
                                bool ok;
                                deadKeyIndex = parseHex(token, ok);
                                deadKeyIndex--; // Make index 0 based instead of 1 based
                                if (!ok || deadKeyIndex >= NUM_DEAD_KEYS) {
                                        throw MSXException(
                                                "Wrong deadkey number in keymap file. "
                                                "It must be 1..", NUM_DEAD_KEYS);
                                }
                        }
                } else {
                        bool ok;
                        unicode = parseHex(token, ok);
                        if (!ok || unicode > 0x1FBAF) {
                                throw MSXException("Wrong unicode value in keymap file");
                        }
                }

                // Parse second token. It must be <ROW><COL>
                token = nextToken(data);
                if (token == "--") {
                        // Skip -- for now, it means the character cannot be typed.
                        continue;
                }
                bool ok;
                unsigned rowcol = parseHex(token, ok);
                if (!ok || rowcol >= 0x100) {
                        throw MSXException(
                                (token.empty() ? "Missing" : "Wrong"),
                                " <ROW><COL> value in keymap file");
                }
                if ((rowcol >> 4) >= KeyMatrixPosition::NUM_ROWS) {
                        throw MSXException("Too high row value in keymap file");
                }
                if ((rowcol & 0x0F) >= KeyMatrixPosition::NUM_COLS) {
                        throw MSXException("Too high column value in keymap file");
                }
                auto pos = KeyMatrixPosition(rowcol);

                // Parse remaining tokens. It is an optional list of modifier keywords.
                byte modmask = 0;
                while (true) {
                        token = nextToken(data);
                        if (token.empty()) {
                                break;
                        } else if (token == "SHIFT") {
                                modmask |= KeyInfo::SHIFT_MASK;
                        } else if (token == "CTRL") {
                                modmask |= KeyInfo::CTRL_MASK;
                        } else if (token == "GRAPH") {
                                modmask |= KeyInfo::GRAPH_MASK;
                        } else if (token == "CAPSLOCK") {
                                modmask |= KeyInfo::CAPS_MASK;
                        } else if (token == "CODE") {
                                modmask |= KeyInfo::CODE_MASK;
                        } else {
                                throw MSXException(
                                        "Invalid modifier \"", token, "\" in keymap file");
                        }
                }

                if (isDeadKey) {
                        if (modmask != 0) {
                                throw MSXException(
                                        "DEADKEY entry in keymap file cannot have modifiers");
                        }
                        deadKeys[deadKeyIndex] = KeyInfo(pos, 0);
                } else {
                        mapdata.emplace_back(unicode, KeyInfo(pos, modmask));
                        // Note: getRowCol() uses 3 bits for column, rowcol uses 4.
                        relevantMods[pos.getRowCol()] |= modmask;
                }
        }

        ranges::sort(mapdata, LessTupleElement<0>());
}

} // namespace openmsx