Method ShowOpenFileDialog

Source/Engine/Platform/Linux/LinuxFileSystem.cpp:23–106

const DateTime UnixEpoch(1970, 1, 1);

bool LinuxFileSystem::ShowOpenFileDialog(Window* parentWindow, const StringView& initialDirectory, const StringView& filter, bool multiSelect, const StringView& title, Array<String, HeapAllocation>& filenames)
{
    const StringAsUTF8<> initialDirectoryAnsi(*initialDirectory, initialDirectory.Length());
    const StringAsUTF8<> titleAnsi(*title, title.Length());
    const char* initDir = initialDirectory.HasChars() ? initialDirectoryAnsi.Get() : ".";
    String xdgCurrentDesktop;
    StringBuilder fileFilter;
    Array<String> fileFilterEntries;
    Platform::GetEnvironmentVariable(TEXT("XDG_CURRENT_DESKTOP"), xdgCurrentDesktop);
    StringUtils::GetZZString(filter.Get()).Split('\0', fileFilterEntries);

    const bool zenitySupported = FileSystem::FileExists(TEXT("/usr/bin/zenity"));
    const bool kdialogSupported = FileSystem::FileExists(TEXT("/usr/bin/kdialog"));
    char cmd[2048];
    if (zenitySupported && (xdgCurrentDesktop != TEXT("KDE") || !kdialogSupported)) // Prefer kdialog when running on KDE
    {
        for (int32 i = 1; i < fileFilterEntries.Count(); i += 2)
        {
            String extensions(fileFilterEntries[i]);
            fileFilterEntries[i].Replace(TEXT(";"), TEXT(" "));
            fileFilter.Append(String::Format(TEXT("{0}--file-filter=\"{1}|{2}\""), i > 1 ? TEXT(" ") : TEXT(""), fileFilterEntries[i-1].Get(), extensions.Get()));
        }

        sprintf(cmd, "/usr/bin/zenity --modal --file-selection %s--filename=\"%s\" --title=\"%s\" %s ", multiSelect ? "--multiple --separator=$'\n' " : " ", initDir, titleAnsi.Get(), fileFilter.ToStringView().ToStringAnsi().GetText());
    }
    else if (kdialogSupported)
    {
        for (int32 i = 1; i < fileFilterEntries.Count(); i += 2)
        {
            String extensions(fileFilterEntries[i]);
            fileFilterEntries[i].Replace(TEXT(";"), TEXT(" "));
            fileFilter.Append(String::Format(TEXT("{0}\"{1}({2})\""), i > 1 ? TEXT(" ") : TEXT(""), fileFilterEntries[i-1].Get(), extensions.Get()));
        }
        fileFilter.Append(String::Format(TEXT("{0}\"{1}({2})\""), TEXT(" "), TEXT("many things"), TEXT("*.png *.jpg")));

        sprintf(cmd, "/usr/bin/kdialog --getopenfilename %s--title \"%s\" \"%s\" %s ", multiSelect ? "--multiple --separate-output " : " ", titleAnsi.Get(), initDir, fileFilter.ToStringView().ToStringAnsi().GetText());
    }
    else
    {
        LOG(Error, "Missing file picker (install zenity or kdialog).");
        return true;    
    }
    FILE* f = popen(cmd, "r");
    char buf[2048];
    char* writePointer = buf;
    int remainingCapacity = ARRAY_COUNT(buf);
    // make sure we read all output from kdialog
    while (remainingCapacity > 0 && fgets(writePointer, remainingCapacity, f))
    {
        int r = strlen(writePointer);
        writePointer += r;
        remainingCapacity -= r;
    }
    if (remainingCapacity <= 0)
    {
        LOG(Error, "You selected more files than an internal buffer can hold. Try selecting fewer files at a time.");
        // in case of an overflow we miss the closing null byte, add it after the rightmost linefeed
        while (*writePointer != '\n')