conversion of TextStyle

ocrd_page_to_alto/convert.py

@@ -10,6 +10,7 @@
     set_alto_shape_from_coords,
     setxml
 )
+from .styles import TextStylesManager
 
 NAMESPACES = {**NAMESPACES_}
 NAMESPACES['xsi'] = 'http://www.w3.org/2001/XMLSchema-instance'
@@ -62,6 +63,7 @@ def __init__(self, *, check_words=True, check_border=True, skip_empty_lines=Fals
                 raise ValueError("The PAGE-XML to transform contains neither Border nor PrintSpace")
         self.alto_alto, self.alto_description, self.alto_styles, self.alto_tags, self.alto_page = self.create_alto()
         self.alto_printspace = self.convert_border()
+        self.textstyle_mgr = TextStylesManager()
 
     def __str__(self):
         return ET.tostring(self.alto_alto, pretty_print=True).decode('utf-8')
@@ -83,6 +85,10 @@ def convert(self):
         self.convert_metadata()
         self.convert_text()
         self.convert_reading_order()
+        self.convert_styles()
+
+    def convert_styles(self):
+        self.textstyle_mgr.to_xml(self.alto_styles)
 
     def convert_reading_order(self):
         index_order = [x.id for x in self.page_page.get_AllRegions(order='reading-order', depth=1)]
@@ -151,13 +157,14 @@ def _convert_textlines(self, reg_alto, reg_page):
             if is_empty_line and self.skip_empty_lines:
                 return
             line_alto = ET.SubElement(reg_alto, 'TextLine')
-            if is_empty_line:
-                word_alto_empty = ET.SubElement(line_alto, 'String')
-                word_alto_empty.set('CONTENT', '')
             set_alto_id_from_page_id(line_alto, line_page)
             set_alto_xywh_from_coords(line_alto, line_page)
             set_alto_shape_from_coords(line_alto, line_page)
+            self.set_alto_styleref_from_textstyle(line_alto, line_page)
             # XXX ALTO does not allow TextLine without at least one String
+            if is_empty_line:
+                word_alto_empty = ET.SubElement(line_alto, 'String')
+                word_alto_empty.set('CONTENT', '')
             for word_page in line_page.get_Word():
                 word_alto = ET.SubElement(line_alto, 'String')
                 set_alto_id_from_page_id(word_alto, word_page)
@@ -175,6 +182,7 @@ def convert_text(self):
             set_alto_id_from_page_id(reg_alto, reg_page)
             set_alto_xywh_from_coords(reg_alto, reg_page)
             set_alto_shape_from_coords(reg_alto, reg_page)
+            self.set_alto_styleref_from_textstyle(reg_alto, reg_page)
             if reg_page_type == 'Text':
                 self._convert_textlines(reg_alto, reg_page)
             elif reg_page_type == 'Table':
@@ -186,3 +194,8 @@ def convert_text(self):
             else:
                 raise ValueError('Unhandled region type %s' % reg_page_type)
 
+
+    def set_alto_styleref_from_textstyle(self, reg_alto, reg_page):
+        textstyle = reg_page.get_TextStyle() if hasattr(reg_page, 'get_TextStyle') else None
+        if textstyle:
+            reg_alto.set('STYLEREFS', self.textstyle_mgr.from_textstyle(textstyle))

ocrd_page_to_alto/styles.py

@@ -0,0 +1,92 @@
+from lxml import etree as ET
+
+class TextStylesManager():
+
+    def __init__(self):
+        self._styles = set()
+        self.fields = ('font_family', 'font_type', 'font_width', 'font_size', 'font_color', 'font_style')
+        self.output_element = 'TextStyle'
+
+    def get_style_id(self, **kwargs):
+        if any(k not in self.fields for k in kwargs):
+            raise ValueError(f"Unknown fields in {kwargs}")
+        key = '---'.join([str(kwargs.get(x, None)).replace(' ', '%20') for x in self.fields])
+        if key not in self.styles:
+            self._styles.add(key)
+        return key
+
+    @property
+    def styles(self):
+        ret = {}
+        for key in self._styles:
+            ret[key] = {}
+            vals = key.split('---')
+            for field_idx, field in enumerate(self.fields):
+                ret[key][field] = vals[field_idx].replace('%20', ' ')
+        return ret
+
+    def from_textstyle(self, textstyle):
+        kwargs = {}
+        print(textstyle)
+        kwargs['font_family'] = textstyle.fontFamily
+        kwargs['font_type'] = 'serif' if textstyle.serif else 'sans-serif'
+        kwargs['font_width'] = 'fixed' if textstyle.monospace else 'proportional'
+        if textstyle.fontSize:
+            kwargs['font_size'] = textstyle.fontSize
+        if textstyle.textColourRgb:
+            b = textstyle.textColourRgb // 65336
+            g = (textstyle.textColourRgb - (b * 65336)) // 256
+            r = textstyle.textColourRgb - (b * 65336) - (g * 256)
+            kwargs['font_color'] = '%2x%2x%2x' % (r, g, b)
+        if textstyle.textColour:
+            # https://en.wikipedia.org/wiki/Web_colors
+            rgb = 'ffffff' if textstyle.textColour == 'white' else \
+                  '000000' if textstyle.textColour == 'black' else \
+                  'ff0000' if textstyle.textColour == 'red' else \
+                  '800000' if textstyle.textColour == 'brown' else \
+                  '00ffff' if textstyle.fontColour == 'cyan' else \
+                  '00ff00' if textstyle.fontColour == 'green' else \
+                  '999999' if textstyle.fontColour == 'grey' else \
+                  '4b0082' if textstyle.fontColour == 'indigo' else \
+                  'ff00ff' if textstyle.fontColour == 'magenta' else \
+                  'ffa500' if textstyle.fontColour == 'orange' else \
+                  'ff00cb' if textstyle.fontColour == 'pink' else \
+                  '40e0d0' if textstyle.fontColour == 'turquoise' else \
+                  'ee82ee' if textstyle.fontColour == 'violet' else \
+                  'ffff00' if textstyle.fontColour == 'yellow' else \
+                  None
+            if rgb:
+                kwargs['font_color'] = rgb
+        font_style = []
+        if textstyle.italic:
+            font_style.append('italics')
+        if textstyle.underlined:
+            font_style.append('underline')
+        for att in ('bold', 'smallCaps', 'strikethrough', 'subscript', 'superscript'):
+            if getattr(textstyle, att):
+                font_style.append(att.lower())
+        if font_style:
+            kwargs['font_style'] = ' '.join(font_style)
+        # TODO kerning
+        # TODO underlineStyle
+        # TODO bgColour
+        # TODO bgColourRgb
+        # TODO reverseVideo
+        # TODO xHeight
+        # TODO letterSpaced
+        return self.get_style_id(**kwargs)
+
+    def to_xml(self, alto_styles):
+        for style_id, style in self.styles.items():
+            el_style = ET.SubElement(alto_styles, self.output_element)
+            el_style.set('ID', style_id)
+            for k, v in style.items():
+                if v != 'None':
+                    el_style.set(k.replace('_', '').upper(), v)
+
+class ParagraphStyleManager(TextStylesManager):
+
+    def __ini__(self):
+        super().__init__()
+        self.fields = ('align', 'left', 'right', 'line_space', 'first_line')
+        self.output_element = 'ParagraphStyle'

ocrd_page_to_alto/utils.py

@@ -1,6 +1,9 @@
 from lxml import etree as ET
 from ocrd_utils import xywh_from_points
 
+def setxml(el, name, val):
+    el.set(name, str(val))
+
 def set_alto_xywh_from_coords(reg_alto, reg_page, classes=None):
     if classes is None:
         classes = ['HEIGHT', 'WIDTH', 'HPOS', 'VPOS']
@@ -21,7 +24,3 @@ def set_alto_shape_from_coords(reg_alto, reg_page):
 
 def set_alto_id_from_page_id(reg_alto, reg_page):
     setxml(reg_alto, 'ID', reg_page.id)
-
-def setxml(el, name, val):
-    el.set(name, str(val))
-

tests/test_styles.py

@@ -0,0 +1,27 @@
+from pytest import raises, main, fixture
+from lxml import etree as ET
+from ocrd_models.ocrd_page import TextStyleType, to_xml
+
+from ocrd_page_to_alto.styles import TextStylesManager
+
+def test_styles_id():
+    m = TextStylesManager()
+    assert m.get_style_id(font_family='Foo') == 'Foo---None---None---None---None---None'
+    assert m.styles['Foo---None---None---None---None---None']['font_family'] == 'Foo'
+
+def test_styles_to_xml():
+    m = TextStylesManager()
+    m.get_style_id(font_family='Foo Serif')
+    el = ET.Element('Styles')
+    m.to_xml(el)
+    assert ET.tostring(el).decode('utf-8') == '<Styles><TextStyle ID="Foo%20Serif---None---None---None---None---None" FONTFAMILY="Foo Serif"/></Styles>'
+    assert m.styles['Foo%20Serif---None---None---None---None---None']['font_family'] == 'Foo Serif'
+
+def test_styles_from_textstyle():
+    m = TextStylesManager()
+    textstyle = TextStyleType(fontFamily='Times New Roman', serif=True, textColourRgb=6559300)
+    print(m.from_textstyle(textstyle))
+    assert 0
+
+if __name__ == "__main__":
+    main([__file__])