pdf2htmlEX/src/HTMLRenderer/general.cc

/*
 * general.cc
 *
 * Hanlding general stuffs
 *
 * by WangLu
 * 2012.08.14
 */

#include <cstdio>
#include <ostream>

#include <splash/SplashBitmap.h>
#include <Link.h>

#include "HTMLRenderer.h"
#include "BackgroundRenderer.h"
#include "namespace.h"
#include "ff.h"
#include "pdf2htmlEX-config.h"

namespace pdf2htmlEX {

using std::fixed;
using std::flush;
using std::ostream;

static void dummy(void *, enum ErrorCategory, int pos, char *)
{
}

HTMLRenderer::HTMLRenderer(const Param * param)
    :OutputDev()
    ,line_opened(false)
    ,line_buf(this)
    ,image_count(0)
    ,param(param)
{
    //disable error function of poppler
    setErrorCallback(&dummy, nullptr);

    ff_init();
    cur_mapping = new int32_t [0x10000];
    cur_mapping2 = new char* [0x100];
}

HTMLRenderer::~HTMLRenderer()
{ 
    ff_fin();
    clean_tmp_files();
    delete [] cur_mapping;
    delete [] cur_mapping2;
}

static GBool annot_cb(Annot *, void *) {
    return false;
};

void HTMLRenderer::process(PDFDoc *doc)
{
    cur_doc = doc;
    xref = doc->getXRef();

    cerr << "Preprocessing: ";
    for(int i = param->first_page; i <= param->last_page ; ++i) 
    {
        doc->displayPage(&font_preprocessor, i, param->h_dpi, param->v_dpi,
                0, true, false, false,
                nullptr, nullptr, nullptr, nullptr);
        cerr << "." << flush;
    }
    cerr << endl;

    cerr << "Working: ";
    BackgroundRenderer * bg_renderer = nullptr;
    if(param->process_nontext)
    {
        // Render non-text objects as image
        // copied from poppler
        SplashColor color;
        color[0] = color[1] = color[2] = 255;

        bg_renderer = new BackgroundRenderer(splashModeRGB8, 4, gFalse, color);
        bg_renderer->startDoc(doc);
    }

    pre_process();

    for(int i = param->first_page; i <= param->last_page ; ++i) 
    {
        if(param->split_pages)
        {
            auto page_fn = str_fmt("%s/%s%d.page", param->dest_dir.c_str(), param->output_filename.c_str(), i);
            html_fout.open((char*)page_fn, ofstream::binary); 
            fix_stream(html_fout);
        }

        if(param->process_nontext)
        {
            doc->displayPage(bg_renderer, i, param->h_dpi, param->v_dpi,
                    0, true, false, false,
                    nullptr, nullptr, &annot_cb, nullptr);

            {
                auto fn = str_fmt("%s/p%x.png", (param->single_html ? param->tmp_dir : param->dest_dir).c_str(), i);
                if(param->single_html)
                    add_tmp_file((char*)fn);

                bg_renderer->getBitmap()->writeImgFile(splashFormatPng, 
                        (char*)fn,
                        param->h_dpi, param->v_dpi);
            }
        }

        doc->displayPage(this, i, param->zoom * DEFAULT_DPI, param->zoom * DEFAULT_DPI,
                0, true, false, false,
                nullptr, nullptr, nullptr, nullptr);

        if(param->split_pages)
        {
            html_fout.close();
        }

        cerr << "." << flush;
    }

    post_process();

    if(bg_renderer)
        delete bg_renderer;

    cerr << endl;
}

void HTMLRenderer::setDefaultCTM(double *ctm)
{
    memcpy(default_ctm, ctm, sizeof(default_ctm));
}

GBool HTMLRenderer::checkPageSlice(Page *page, double hDPI, double vDPI,
    int rotate, GBool useMediaBox, GBool crop,
    int sliceX, int sliceY, int sliceW, int sliceH,
    GBool printing,
    GBool (* abortCheckCbk)(void *data),
    void * abortCheckCbkData,
    GBool (*annotDisplayDecideCbk)(Annot *annot, void *user_data),
    void *annotDisplayDecideCbkData)
{
    cur_page = page;
    return gTrue;
}

void HTMLRenderer::startPage(int pageNum, GfxState *state) 
{
    this->pageNum = pageNum;
    this->pageWidth = state->getPageWidth();
    this->pageHeight = state->getPageHeight();

    assert((!line_opened) && "Open line in startPage detected!");

    html_fout << "<div class=\"b\" style=\"width:" << pageWidth << "px;height:" << pageHeight << "px;\">"
        << "<div id=\"p" << pageNum << "\" class=\"p\" style=\"width:" << pageWidth << "px;height:" << pageHeight << "px;";

    html_fout << "background-image:url(";

    {
        if(param->single_html)
        {
            auto path = str_fmt("%s/p%x.png", param->tmp_dir.c_str(), pageNum);
            ifstream fin((char*)path, ifstream::binary);
            if(!fin)
                throw string("Cannot read background image ") + (char*)path;
            html_fout << "'data:image/png;base64," << base64stream(fin) << "'";
        }
        else
        {
            html_fout << str_fmt("p%x.png", pageNum);
        }
    }
    
    html_fout << ");background-position:0 0;background-size:" << pageWidth << "px " << pageHeight << "px;background-repeat:no-repeat;\">";

    html_fout << "<a name=\"p" << pageNum << "\"></a>";
            
    draw_scale = 1.0;

    cur_font_info = install_font(nullptr);
    cur_font_size = draw_font_size = 0;
    cur_fs_id = install_font_size(cur_font_size);
    
    memcpy(cur_ctm, id_matrix, sizeof(cur_ctm));
    memcpy(draw_ctm, id_matrix, sizeof(draw_ctm));
    cur_tm_id = install_transform_matrix(draw_ctm);

    cur_letter_space = cur_word_space = 0;
    cur_ls_id = install_letter_space(cur_letter_space);
    cur_ws_id = install_word_space(cur_word_space);

    cur_color.r = cur_color.g = cur_color.b = 0;
    cur_color_id = install_color(&cur_color);

    cur_rise = 0;
    cur_rise_id = install_rise(cur_rise);

    cur_tx = cur_ty = 0;
    draw_tx = draw_ty = 0;

    reset_state_change();
    all_changed = true;
}

void HTMLRenderer::endPage() {
    close_line();
    process_links();
    // close page
    html_fout << "</div></div>" << endl;
}

void HTMLRenderer::pre_process()
{
    // we may output utf8 characters, so always use binary
    {
        /*
         * If single-html && !split-pages
         * we have to keep the generated css file into a temporary place
         * and embed it into the main html later
         *
         *
         * If single-html && split-page
         * as there's no place to embed the css file, just leave it alone (into param->dest_dir)
         *
         * If !single-html
         * leave it in param->dest_dir
         */

        auto fn = (param->single_html && (!param->split_pages))
            ? str_fmt("%s/__css", param->tmp_dir.c_str())
            : str_fmt("%s/%s", param->dest_dir.c_str(), param->css_filename.c_str());

        if(param->single_html && (!param->split_pages))
            add_tmp_file((char*)fn);

        css_path = (char*)fn,
        css_fout.open(css_path, ofstream::binary);
        fix_stream(css_fout);
    }

    // if split-pages is specified, open & close the file in the process loop
    // if not, open the file here:
    if(!param->split_pages)
    {
        /*
         * If single-html
         * we have to keep the html file (for page) into a temporary place
         * because we'll have to embed css before it
         *
         * Otherwise just generate it 
         */
        auto fn = str_fmt("%s/__pages", param->tmp_dir.c_str());
        add_tmp_file((char*)fn);

        html_path = (char*)fn;
        html_fout.open(html_path, ofstream::binary); 
        fix_stream(html_fout);
    }
}

void HTMLRenderer::post_process()
{
    // close files
    html_fout.close(); 
    css_fout.close();

    //only when split-page, do we have some work left to do
    if(param->split_pages)
        return;

    ofstream output((char*)str_fmt("%s/%s", param->dest_dir.c_str(), param->output_filename.c_str()));
    fix_stream(output);

    // apply manifest
    ifstream manifest_fin((char*)str_fmt("%s/%s", param->data_dir.c_str(), MANIFEST_FILENAME.c_str()));
    if(!manifest_fin)
        throw "Cannot open the manifest file";

    bool embed_string = false;
    string line;
    while(getline(manifest_fin, line))
    {
        if(line == "\"\"\"")
        {
            embed_string = !embed_string;
            continue;
        }

        if(embed_string)
        {
            output << line << endl;
            continue;
        }

        if(line.empty() || line[0] == '#')
            continue;


        if(line[0] == '@')
        {
            embed_file(output, param->data_dir + "/" + line.substr(1), "", true);
            continue;
        }

        if(line[0] == '$')
        {
            if(line == "$css")
            {
                embed_file(output, css_path, ".css", false);
            }
            else if (line == "$pages")
            {
                ifstream fin(html_path, ifstream::binary);
                if(!fin)
                    throw "Cannot open read the pages";
                output << fin.rdbuf();
            }
            else
            {
                cerr << "Warning: unknown line in manifest: " << line << endl;
            }
            continue;
        }

        cerr << "Warning: unknown line in manifest: " << line << endl;
    }
}

void HTMLRenderer::process_links (void)
{
    Links * links = cur_page->getLinks();
    for(int i = 0; i < links->getNumLinks(); ++i)
    {
        AnnotLink * al = links->getLink(i);
        draw_annot_link(al);
    }
    delete links;
}

/*
 * Based on pdftohtml from poppler
 */
void HTMLRenderer::draw_annot_link (AnnotLink * al)
{
    std::string dest_str;
    auto action = al->getAction();
    if(action)
    {
        auto kind = action->getKind();
        switch(kind)
        {
            case actionGoTo:
                {
                    auto catalog = cur_doc->getCatalog();
                    auto * real_action = dynamic_cast<LinkGoTo*>(action);
                    LinkDest * dest = nullptr;
                    if(auto _ = real_action->getDest())
                        dest = _->copy();
                    else if (auto _ = real_action->getNamedDest())
                        dest = catalog->findDest(_);
                    if(dest)
                    {
                        int pageno = 0;
                        if(dest->isPageRef())
                        {
                            auto pageref = dest->getPageRef();
                            pageno = catalog->findPage(pageref.num, pageref.gen);
                        }
                        else
                        {
                            pageno = dest->getPageNum();
                        }

                        delete dest;

                        if(pageno > 0)
                            dest_str = (char*)str_fmt("#p%x", pageno);
                    }
                }
                break;
            case actionGoToR:
                {
                    cerr << "TODO: actionGoToR is not implemented." << endl;
                }
                break;
            case actionURI:
                {
                    auto * real_action = dynamic_cast<LinkURI*>(action);
                    dest_str = real_action->getURI()->getCString();
                }
                break;
            case actionLaunch:
                {
                    cerr << "TODO: actionLaunch is not implemented." << endl;
                }
                break;
            default:
                cerr << "Warning: unknown annotation type: " << kind << endl;
                break;
        }
    }

    if(dest_str != "")
    {
        html_fout << "<a href=\"" << dest_str << "\">";
    }

    double x1,x2,y1,y2;
    al->getRect(&x1, &y1, &x2, &y2);

    x1 = default_ctm[0] * x1 + default_ctm[2] * y1 + default_ctm[4];
    y1 = default_ctm[1] * x1 + default_ctm[3] * y1 + default_ctm[5];
    x2 = default_ctm[0] * x2 + default_ctm[2] * y2 + default_ctm[4];
    y2 = default_ctm[1] * x2 + default_ctm[3] * y2 + default_ctm[5];

    html_fout << "<div style=\"border:1px solid;position:absolute;"
        << "left:" << x1 << "px;"
        << "bottom:" << y1 << "px;"
        << "width:" << (x2-x1) << "px;"
        << "height:" << (y2-y1) << "px;"
        << "\"></div>";

    if(dest_str != "")
    {
        html_fout << "</a>";
    }
}

void HTMLRenderer::fix_stream (std::ostream & out)
{
    out << hex;
}

void HTMLRenderer::add_tmp_file(const string & fn)
{
    if(!param->clean_tmp)
        return;

    if(tmp_files.insert(fn).second && param->debug)
        cerr << "Add new temporary file: " << fn << endl;
}

void HTMLRenderer::clean_tmp_files()
{
    if(!param->clean_tmp)
        return;

    for(auto iter = tmp_files.begin(); iter != tmp_files.end(); ++iter)
    {
        const string & fn = *iter;
        remove(fn.c_str());
        if(param->debug)
            cerr << "Remove temporary file: " << fn << endl;
    }

    remove(param->tmp_dir.c_str());
    if(param->debug)
        cerr << "Remove temporary directory: " << param->tmp_dir << endl;
}

void HTMLRenderer::embed_file(ostream & out, const string & path, const string & type, bool copy)
{
    string fn = get_filename(path);
    string suffix = (type == "") ? get_suffix(fn) : type; 
    
    auto iter = EMBED_STRING_MAP.find(make_pair(suffix, (bool)param->single_html));
    if(iter == EMBED_STRING_MAP.end())
    {
        cerr << "Warning: unknown suffix: " << suffix << endl;
        return;
    }
    
    if(param->single_html)
    {
        ifstream fin(path, ifstream::binary);
        if(!fin)
            throw string("Cannot open file for embedding: ") + path;
        out << iter->second.first << endl
            << fin.rdbuf()
            << iter->second.second << endl;
    }
    else
    {
        out << iter->second.first
            << fn
            << iter->second.second << endl;

        if(copy)
        {
            ifstream fin(path, ifstream::binary);
            if(!fin)
                throw string("Cannot copy file: ") + path;
            ofstream(param->dest_dir + "/" + fn, ofstream::binary) << fin.rdbuf();
        }
    }
}

const std::string HTMLRenderer::MANIFEST_FILENAME = "manifest";

}// namespace pdf2htmlEX