From 95279fbf6dfeb43d80590740a9259d7caa614177 Mon Sep 17 00:00:00 2001 From: Mavridis Philippe Date: Sat, 5 Feb 2022 17:44:26 +0000 Subject: Add tdemarkdown part - embeddable lightweight markdown viewing component. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit TDEMarkdown is based on the md4c library and using TDEHTML for rendering its output. For enhanced safety, on HTML widget is turned off everything we don't need for viewing. It integrates nicely into Konqueror and supports both Commonmark and GitHub markdown syntaxes. Signed-off-by: Mavridis Philippe Prepare to merge tdemarkdown into tdelibs. Signed-off-by: Slávek Banko --- tdemarkdown/md4c/src/md4c-html.c | 573 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 573 insertions(+) create mode 100644 tdemarkdown/md4c/src/md4c-html.c (limited to 'tdemarkdown/md4c/src/md4c-html.c') diff --git a/tdemarkdown/md4c/src/md4c-html.c b/tdemarkdown/md4c/src/md4c-html.c new file mode 100644 index 000000000..d604aecb0 --- /dev/null +++ b/tdemarkdown/md4c/src/md4c-html.c @@ -0,0 +1,573 @@ +/* + * MD4C: Markdown parser for C + * (http://github.com/mity/md4c) + * + * Copyright (c) 2016-2019 Martin Mitas + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#include +#include + +#include "md4c-html.h" +#include "entity.h" + + +#if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 199409L + /* C89/90 or old compilers in general may not understand "inline". */ + #if defined __GNUC__ + #define inline __inline__ + #elif defined _MSC_VER + #define inline __inline + #else + #define inline + #endif +#endif + +#ifdef _WIN32 + #define snprintf _snprintf +#endif + + + +typedef struct MD_HTML_tag MD_HTML; +struct MD_HTML_tag { + void (*process_output)(const MD_CHAR*, MD_SIZE, void*); + void* userdata; + unsigned flags; + int image_nesting_level; + char escape_map[256]; +}; + +#define NEED_HTML_ESC_FLAG 0x1 +#define NEED_URL_ESC_FLAG 0x2 + + +/***************************************** + *** HTML rendering helper functions *** + *****************************************/ + +#define ISDIGIT(ch) ('0' <= (ch) && (ch) <= '9') +#define ISLOWER(ch) ('a' <= (ch) && (ch) <= 'z') +#define ISUPPER(ch) ('A' <= (ch) && (ch) <= 'Z') +#define ISALNUM(ch) (ISLOWER(ch) || ISUPPER(ch) || ISDIGIT(ch)) + + +static inline void +render_verbatim(MD_HTML* r, const MD_CHAR* text, MD_SIZE size) +{ + r->process_output(text, size, r->userdata); +} + +/* Keep this as a macro. Most compiler should then be smart enough to replace + * the strlen() call with a compile-time constant if the string is a C literal. */ +#define RENDER_VERBATIM(r, verbatim) \ + render_verbatim((r), (verbatim), (MD_SIZE) (strlen(verbatim))) + + +static void +render_html_escaped(MD_HTML* r, const MD_CHAR* data, MD_SIZE size) +{ + MD_OFFSET beg = 0; + MD_OFFSET off = 0; + + /* Some characters need to be escaped in normal HTML text. */ + #define NEED_HTML_ESC(ch) (r->escape_map[(unsigned char)(ch)] & NEED_HTML_ESC_FLAG) + + while(1) { + /* Optimization: Use some loop unrolling. */ + while(off + 3 < size && !NEED_HTML_ESC(data[off+0]) && !NEED_HTML_ESC(data[off+1]) + && !NEED_HTML_ESC(data[off+2]) && !NEED_HTML_ESC(data[off+3])) + off += 4; + while(off < size && !NEED_HTML_ESC(data[off])) + off++; + + if(off > beg) + render_verbatim(r, data + beg, off - beg); + + if(off < size) { + switch(data[off]) { + case '&': RENDER_VERBATIM(r, "&"); break; + case '<': RENDER_VERBATIM(r, "<"); break; + case '>': RENDER_VERBATIM(r, ">"); break; + case '"': RENDER_VERBATIM(r, """); break; + } + off++; + } else { + break; + } + beg = off; + } +} + +static void +render_url_escaped(MD_HTML* r, const MD_CHAR* data, MD_SIZE size) +{ + static const MD_CHAR hex_chars[] = "0123456789ABCDEF"; + MD_OFFSET beg = 0; + MD_OFFSET off = 0; + + /* Some characters need to be escaped in URL attributes. */ + #define NEED_URL_ESC(ch) (r->escape_map[(unsigned char)(ch)] & NEED_URL_ESC_FLAG) + + while(1) { + while(off < size && !NEED_URL_ESC(data[off])) + off++; + if(off > beg) + render_verbatim(r, data + beg, off - beg); + + if(off < size) { + char hex[3]; + + switch(data[off]) { + case '&': RENDER_VERBATIM(r, "&"); break; + default: + hex[0] = '%'; + hex[1] = hex_chars[((unsigned)data[off] >> 4) & 0xf]; + hex[2] = hex_chars[((unsigned)data[off] >> 0) & 0xf]; + render_verbatim(r, hex, 3); + break; + } + off++; + } else { + break; + } + + beg = off; + } +} + +static unsigned +hex_val(char ch) +{ + if('0' <= ch && ch <= '9') + return ch - '0'; + if('A' <= ch && ch <= 'Z') + return ch - 'A' + 10; + else + return ch - 'a' + 10; +} + +static void +render_utf8_codepoint(MD_HTML* r, unsigned codepoint, + void (*fn_append)(MD_HTML*, const MD_CHAR*, MD_SIZE)) +{ + static const MD_CHAR utf8_replacement_char[] = { 0xef, 0xbf, 0xbd }; + + unsigned char utf8[4]; + size_t n; + + if(codepoint <= 0x7f) { + n = 1; + utf8[0] = codepoint; + } else if(codepoint <= 0x7ff) { + n = 2; + utf8[0] = 0xc0 | ((codepoint >> 6) & 0x1f); + utf8[1] = 0x80 + ((codepoint >> 0) & 0x3f); + } else if(codepoint <= 0xffff) { + n = 3; + utf8[0] = 0xe0 | ((codepoint >> 12) & 0xf); + utf8[1] = 0x80 + ((codepoint >> 6) & 0x3f); + utf8[2] = 0x80 + ((codepoint >> 0) & 0x3f); + } else { + n = 4; + utf8[0] = 0xf0 | ((codepoint >> 18) & 0x7); + utf8[1] = 0x80 + ((codepoint >> 12) & 0x3f); + utf8[2] = 0x80 + ((codepoint >> 6) & 0x3f); + utf8[3] = 0x80 + ((codepoint >> 0) & 0x3f); + } + + if(0 < codepoint && codepoint <= 0x10ffff) + fn_append(r, (char*)utf8, (MD_SIZE)n); + else + fn_append(r, utf8_replacement_char, 3); +} + +/* Translate entity to its UTF-8 equivalent, or output the verbatim one + * if such entity is unknown (or if the translation is disabled). */ +static void +render_entity(MD_HTML* r, const MD_CHAR* text, MD_SIZE size, + void (*fn_append)(MD_HTML*, const MD_CHAR*, MD_SIZE)) +{ + if(r->flags & MD_HTML_FLAG_VERBATIM_ENTITIES) { + render_verbatim(r, text, size); + return; + } + + /* We assume UTF-8 output is what is desired. */ + if(size > 3 && text[1] == '#') { + unsigned codepoint = 0; + + if(text[2] == 'x' || text[2] == 'X') { + /* Hexadecimal entity (e.g. "�")). */ + MD_SIZE i; + for(i = 3; i < size-1; i++) + codepoint = 16 * codepoint + hex_val(text[i]); + } else { + /* Decimal entity (e.g. "&1234;") */ + MD_SIZE i; + for(i = 2; i < size-1; i++) + codepoint = 10 * codepoint + (text[i] - '0'); + } + + render_utf8_codepoint(r, codepoint, fn_append); + return; + } else { + /* Named entity (e.g. " "). */ + const struct entity* ent; + + ent = entity_lookup(text, size); + if(ent != NULL) { + render_utf8_codepoint(r, ent->codepoints[0], fn_append); + if(ent->codepoints[1]) + render_utf8_codepoint(r, ent->codepoints[1], fn_append); + return; + } + } + + fn_append(r, text, size); +} + +static void +render_attribute(MD_HTML* r, const MD_ATTRIBUTE* attr, + void (*fn_append)(MD_HTML*, const MD_CHAR*, MD_SIZE)) +{ + int i; + + for(i = 0; attr->substr_offsets[i] < attr->size; i++) { + MD_TEXTTYPE type = attr->substr_types[i]; + MD_OFFSET off = attr->substr_offsets[i]; + MD_SIZE size = attr->substr_offsets[i+1] - off; + const MD_CHAR* text = attr->text + off; + + switch(type) { + case MD_TEXT_NULLCHAR: render_utf8_codepoint(r, 0x0000, render_verbatim); break; + case MD_TEXT_ENTITY: render_entity(r, text, size, fn_append); break; + default: fn_append(r, text, size); break; + } + } +} + + +static void +render_open_ol_block(MD_HTML* r, const MD_BLOCK_OL_DETAIL* det) +{ + char buf[64]; + + if(det->start == 1) { + RENDER_VERBATIM(r, "
    \n"); + return; + } + + snprintf(buf, sizeof(buf), "
      \n", det->start); + RENDER_VERBATIM(r, buf); +} + +static void +render_open_li_block(MD_HTML* r, const MD_BLOCK_LI_DETAIL* det) +{ + if(det->is_task) { + RENDER_VERBATIM(r, "
    1. " + "task_mark == 'x' || det->task_mark == 'X') + RENDER_VERBATIM(r, " checked"); + RENDER_VERBATIM(r, ">"); + } else { + RENDER_VERBATIM(r, "
    2. "); + } +} + +static void +render_open_code_block(MD_HTML* r, const MD_BLOCK_CODE_DETAIL* det) +{ + RENDER_VERBATIM(r, "
      lang.text != NULL) {
+        RENDER_VERBATIM(r, " class=\"language-");
+        render_attribute(r, &det->lang, render_html_escaped);
+        RENDER_VERBATIM(r, "\"");
+    }
+
+    RENDER_VERBATIM(r, ">");
+}
+
+static void
+render_open_td_block(MD_HTML* r, const MD_CHAR* cell_type, const MD_BLOCK_TD_DETAIL* det)
+{
+    RENDER_VERBATIM(r, "<");
+    RENDER_VERBATIM(r, cell_type);
+
+    switch(det->align) {
+        case MD_ALIGN_LEFT:     RENDER_VERBATIM(r, " align=\"left\">"); break;
+        case MD_ALIGN_CENTER:   RENDER_VERBATIM(r, " align=\"center\">"); break;
+        case MD_ALIGN_RIGHT:    RENDER_VERBATIM(r, " align=\"right\">"); break;
+        default:                RENDER_VERBATIM(r, ">"); break;
+    }
+}
+
+static void
+render_open_a_span(MD_HTML* r, const MD_SPAN_A_DETAIL* det)
+{
+    RENDER_VERBATIM(r, "href, render_url_escaped);
+
+    if(det->title.text != NULL) {
+        RENDER_VERBATIM(r, "\" title=\"");
+        render_attribute(r, &det->title, render_html_escaped);
+    }
+
+    RENDER_VERBATIM(r, "\">");
+}
+
+static void
+render_open_img_span(MD_HTML* r, const MD_SPAN_IMG_DETAIL* det)
+{
+    RENDER_VERBATIM(r, "src, render_url_escaped);
+
+    RENDER_VERBATIM(r, "\" alt=\"");
+
+    r->image_nesting_level++;
+}
+
+static void
+render_close_img_span(MD_HTML* r, const MD_SPAN_IMG_DETAIL* det)
+{
+    if(det->title.text != NULL) {
+        RENDER_VERBATIM(r, "\" title=\"");
+        render_attribute(r, &det->title, render_html_escaped);
+    }
+
+    RENDER_VERBATIM(r, (r->flags & MD_HTML_FLAG_XHTML) ? "\" />" : "\">");
+
+    r->image_nesting_level--;
+}
+
+static void
+render_open_wikilink_span(MD_HTML* r, const MD_SPAN_WIKILINK_DETAIL* det)
+{
+    RENDER_VERBATIM(r, "target, render_html_escaped);
+
+    RENDER_VERBATIM(r, "\">");
+}
+
+
+/**************************************
+ ***  HTML renderer implementation  ***
+ **************************************/
+
+static int
+enter_block_callback(MD_BLOCKTYPE type, void* detail, void* userdata)
+{
+    static const MD_CHAR* head[6] = { "
      ", "
      ", "
      ", "
      ", "
      ", "
      " };
+    MD_HTML* r = (MD_HTML*) userdata;
+
+    switch(type) {
+        case MD_BLOCK_DOC:      /* noop */ break;
+        case MD_BLOCK_QUOTE:    RENDER_VERBATIM(r, "
      \n"); break;
+        case MD_BLOCK_UL:       RENDER_VERBATIM(r, "