Add text parser and render using Pygments

apps/common/textparser.py

@@ -0,0 +1,98 @@
+from pygments import highlight
+from pygments.lexers import TextLexer, guess_lexer, get_lexer_for_filename, ClassNotFound
+from pygments.formatters import ImageFormatter
+
+DEFAULT_PAGE_WIDTH = 70
+DEFAULT_PAGE_HEIGHT = 57
+DEFAULT_LINE_NUMBER_PAD = 19
+CHUNKSIZE = 1024
+NEWLINE = '\n'
+SPACE = ' '
+
+TEXT_PARSER_MIMETYPES = ['text/plain']
+
+
+class TextParser(object):
+    def render_to_viewport(self, filename, page_width=DEFAULT_PAGE_WIDTH, page_height=DEFAULT_PAGE_HEIGHT, fill_last_page=False):
+        """
+        Render an input text file into an imaginary squared view port (terminal window),
+        returning a list of pages which are themselves a list of lines
+        """
+        pages = []
+        with open(filename, 'rU') as descriptor:
+            width = 0
+            height = 0
+            line = []
+            page = []
+            bytes_read = descriptor.read(CHUNKSIZE)
+            while bytes_read:
+                for letter in bytes_read:
+                    if letter != NEWLINE:
+                        line.append(letter)
+                        
+                    width = width + 1
+                    if width >= page_width or letter == NEWLINE:
+                        page.append(''.join(line))
+                        line = []
+                        width = 0
+                        height = height + 1
+                        if height >= page_height:
+                            pages.append(page)
+                            page = []
+                            height = 0
+                        
+                bytes_read = descriptor.read(CHUNKSIZE)
+
+            # Fill any final partial page with empty lines
+            if fill_last_page:
+                for filler in range(DEFAULT_PAGE_HEIGHT - len(page)):
+                    page.append(SPACE)
+
+            # Append any final partial page when chunk ends
+            pages.append(page)
+            
+
+        return pages
+        
+    def render_to_image(self, filename, page_width=DEFAULT_PAGE_WIDTH, page_height=DEFAULT_PAGE_HEIGHT, page_number=None, lexer=None, line_numbers=True, line_number_pad=DEFAULT_LINE_NUMBER_PAD):
+        """
+        Turn a list of pages and lines and product and image representation,
+        selecting the best parser possible based on the filename and contents
+        """
+        pages = self.render_to_viewport(filename, page_width, page_height, fill_last_page=True)
+
+        if not lexer:
+            # Read entire file to guess the lexer
+            with open(filename, 'rb') as descriptor:
+                file_data = descriptor.read()
+                if not lexer:
+                    try:
+                        lexer = get_lexer_for_filename(filename, file_data)
+                    except ClassNotFound, err:
+                        try:
+                            lexer = guess_lexer(file_data)
+                        except ClassNotFound:
+                            lexer = TextLexer()
+        
+        if page_number:
+            # Render a single page into image
+            return highlight('\n'.join(pages[page_number - 1]), lexer, ImageFormatter(line_number_start=(page_number - 1) * page_height + 1, line_numbers=line_numbers, line_number_pad=line_number_pad))
+        else:
+            # Render all pages into image
+            output = []
+        
+            for page, page_number in zip(pages, xrange(len(pages))):
+                output.append(highlight('\n'.join(page), lexer, ImageFormatter(line_number_start=page_number * page_height + 1, line_numbers=line_numbers, line_number_pad=line_number_pad)))
+                
+            return output
+
+            
+#    parser = TextParser()
+#    page_num = 1
+#    #for result in parser.render('docwrap.py'):#, 80):
+#    #for result in parser.render_to_image('input.txt'):#, 80):
+#    for result in parser.render_to_image('../apps/documents/views.py'):#, 80):
+#        FILE = open('page%d' % page_num, 'wb')
+#        FILE.write(result)
+#        FILE.close()
+#        page_num += 1