getPageLinks implementation for mupdf #72

This is rough first draft, and provides just dump of all links
available on pdf page. Binding to Shift+L is temporary and just for
debugging!

pdf.c

@@ -577,6 +577,59 @@ static int cleanCache(lua_State *L) {
 	return 0;
 }
 
+
+static int getPageLinks(lua_State *L) {
+	fz_link *page_links;
+	fz_link *link;
+
+	int link_count;
+
+	PdfPage *page = (PdfPage*) luaL_checkudata(L, 1, "pdfpage");
+
+	page_links = fz_load_links(page->doc->xref, page->page); // page->doc->xref?
+
+	lua_newtable(L); // all links
+
+	link_count = 0;
+
+	for (link = page_links; link; link = link->next) {
+		lua_newtable(L); // new link
+
+		lua_pushstring(L, "x0");
+		lua_pushinteger(L, link->rect.x0);
+		lua_settable(L, -3);
+		lua_pushstring(L, "y0");
+		lua_pushinteger(L, link->rect.y0);
+		lua_settable(L, -3);
+		lua_pushstring(L, "x1");
+		lua_pushinteger(L, link->rect.x1);
+		lua_settable(L, -3);
+		lua_pushstring(L, "y1");
+		lua_pushinteger(L, link->rect.y1);
+		lua_settable(L, -3);
+
+		if (link->dest.kind == FZ_LINK_URI) {
+			lua_pushstring(L, "uri");
+			lua_pushstring(L, link->dest.ld.uri.uri);
+			lua_settable(L, -3);
+		} else if (link->dest.kind == FZ_LINK_GOTO) {
+			lua_pushstring(L, "page");
+			lua_pushinteger(L, link->dest.ld.gotor.page); // FIXME page+1?
+			lua_settable(L, -3);
+		} else {
+			printf("ERROR: unkown link kind: %x", link->dest.kind);
+		}
+
+		lua_rawseti(L, -2, ++link_count);
+    }
+
+	printf("## getPageLinks found %d links in document", link_count);
+
+	fz_drop_link(page->doc->context, page_links);
+
+	return 1;
+}
+
 static const struct luaL_Reg pdf_func[] = {
 	{"openDocument", openDocument},
 	{NULL, NULL}
@@ -599,6 +652,7 @@ static const struct luaL_Reg pdfpage_meth[] = {
 	{"getSize", getPageSize},
 	{"getUsedBBox", getUsedBBox},
 	{"getPageText", getPageText},
+	{"getPageLinks", getPageLinks},
 	{"close", closePage},
 	{"__gc", closePage},
 	{"draw", drawPage},

pdfreader.lua

@@ -45,3 +45,16 @@ function PDFReader:getText(pageno)
 	page:close()
 	return text
 end
+
+function PDFReader:getPageLinks(pageno)
+	local ok, page = pcall(self.doc.openPage, self.doc, pageno)
+	if not ok then
+		-- TODO: error handling
+		return nil
+	end
+	local links = page:getPageLinks()
+	Debug("## page:getPageLinks ", links)
+	page:close()
+	return links
+end
+

unireader.lua

@@ -2062,6 +2062,11 @@ function UniReader:searchHighLight(search)
 end
 
 
+function UniReader:getPageLinks(pageno)
+	Debug("getPageLinks not supported in this format")
+	return nil
+end
+
 -- used in UniReader:showMenu()
 function UniReader:_drawReadingInfo()
 	local width, height = G_width, G_height
@@ -2855,6 +2860,13 @@ function UniReader:addAllCommands()
 			end
 		end
 	)
+	self.commands:add(KEY_L, MOD_SHIFT, "L",
+		"page links",
+		function(unireader)
+			Debug("unireader", unireader)
+			unireader:getPageLinks( unireader.pageno )
+		end
+	)
 	self.commands:add(KEY_BACK,MOD_ALT,"Back",
 		"close document",
 		function(unireader)