Do less

Lib/glyphsLib/__init__.py

@@ -53,6 +53,7 @@ def load_to_ufos(
     family_name=None,
     propagate_anchors=None,
     ufo_module=None,
+    minimal=False,
 ):
     """Load an unpacked .glyphs object to UFO objects."""
 
@@ -68,6 +69,7 @@ def load_to_ufos(
         family_name=family_name,
         propagate_anchors=propagate_anchors,
         ufo_module=ufo_module,
+        minimal=minimal,
     )
 
 
@@ -85,6 +87,7 @@ def build_masters(
     store_editor_state=True,
     write_skipexportglyphs=False,
     ufo_module=None,
+    minimal=False,
 ):
     """Write and return UFOs from the masters and the designspace defined in a
     .glyphs file.
@@ -121,6 +124,7 @@ def build_masters(
         store_editor_state=store_editor_state,
         write_skipexportglyphs=write_skipexportglyphs,
         ufo_module=ufo_module,
+        minimal=minimal,
     )
 
     # Only write full masters to disk. This assumes that layer sources are always part
@@ -131,7 +135,7 @@ def build_masters(
             assert source.font is ufos[source.filename]
             continue
 
-        if create_background_layers:
+        if create_background_layers and not minimal:
             ufo_create_background_layer_for_all_glyphs(source.font)
 
         ufo_path = os.path.join(master_dir, source.filename)

Lib/glyphsLib/builder/__init__.py

@@ -31,6 +31,7 @@ def to_ufos(
     generate_GDEF=True,
     store_editor_state=True,
     write_skipexportglyphs=False,
+    minimal=False,
 ):
     """Take a GSFont object and convert it into one UFO per master.
 
@@ -44,6 +45,10 @@ def to_ufos(
 
     If generate_GDEF is True, write a `table GDEF {...}` statement in the
     UFO's features.fea, containing GlyphClassDef and LigatureCaretByPos.
+
+    If minimal is True, it is assumed that the UFOs will only be used in
+    font production, and unnecessary steps (e.g. converting background layers)
+    will be skipped.
     """
     builder = UFOBuilder(
         font,
@@ -54,6 +59,7 @@ def to_ufos(
         generate_GDEF=generate_GDEF,
         store_editor_state=store_editor_state,
         write_skipexportglyphs=write_skipexportglyphs,
+        minimal=minimal,
     )
 
     result = list(builder.masters)
@@ -73,6 +79,7 @@ def to_designspace(
     generate_GDEF=True,
     store_editor_state=True,
     write_skipexportglyphs=False,
+    minimal=False,
 ):
     """Take a GSFont object and convert it into a Designspace Document + UFOS.
     The UFOs are available as the attribute `font` of each SourceDescriptor of
@@ -107,6 +114,7 @@ def to_designspace(
         generate_GDEF=generate_GDEF,
         store_editor_state=store_editor_state,
         write_skipexportglyphs=write_skipexportglyphs,
+        minimal=minimal,
     )
     return builder.designspace
 

Lib/glyphsLib/builder/builders.py

@@ -69,6 +69,7 @@ def __init__(
         generate_GDEF=True,
         store_editor_state=True,
         write_skipexportglyphs=False,
+        minimal=False,
     ):
         """Create a builder that goes from Glyphs to UFO + designspace.
 
@@ -115,6 +116,7 @@ def __init__(
         self.store_editor_state = store_editor_state
         self.bracket_layers = []
         self.write_skipexportglyphs = write_skipexportglyphs
+        self.minimal = minimal
 
         if propagate_anchors is None:
             propagate_anchors = font.customParameters["Propagate Anchors"]
@@ -186,13 +188,53 @@ def _is_vertical(self):
 
     @property
     def masters(self):
-        """Get an iterator over master UFOs that match the given family_name.
-        """
+        """Get an iterator over master UFOs that match the given family_name."""
         if self._sources:
             for source in self._sources.values():
                 yield source.font
             return
 
+        # TODO(jamesgk) maybe create one font at a time to reduce memory usage
+        # TODO: (jany) in the future, return a lazy iterator that builds UFOs
+        #     on demand.
+        self.to_ufo_font_attributes(self.family_name)
+
+        self.to_ufo_layers()
+
+        for master_id, source in self._sources.items():
+            ufo = source.font
+            master = self.font.masters[master_id]
+            if self.propagate_anchors:
+                self.to_ufo_propagate_font_anchors(ufo)
+            for layer in list(ufo.layers):
+                self.to_ufo_layer_lib(master, ufo, layer)
+
+            # to_ufo_custom_params may apply "Replace Features" or "Replace Prefix"
+            # parameters so it requires UFOs have their features set first; at the
+            # same time, to generate a GDEF table we first need to have defined the
+            # glyphOrder, exported the glyphs and propagated anchors from components.
+            self.to_ufo_master_features(ufo, master)
+            self.to_ufo_custom_params(ufo, master)
+
+        if self.write_skipexportglyphs:
+            # Sanitize skip list and write it to both Designspace- and UFO-level lib
+            # keys. The latter is unnecessary when using e.g. the ufo2ft.compile*FromDS`
+            # functions, but the data may take a different path. Writing it everywhere
+            # can save on surprises/logic in other software.
+            skip_export_glyphs = self._designspace.lib.get("public.skipExportGlyphs")
+            if skip_export_glyphs is not None:
+                skip_export_glyphs = sorted(set(skip_export_glyphs))
+                self._designspace.lib["public.skipExportGlyphs"] = skip_export_glyphs
+                for source in self._sources.values():
+                    source.font.lib["public.skipExportGlyphs"] = skip_export_glyphs
+
+        self.to_ufo_groups()
+        self.to_ufo_kerning()
+
+        for source in self._sources.values():
+            yield source.font
+
+    def to_ufo_layers(self):
         # Store set of actually existing master (layer) ids. This helps with
         # catching dangling layer data that Glyphs may ignore, e.g. when
         # copying glyphs from other fonts with, naturally, different master
@@ -203,11 +245,6 @@ def masters(self):
         # stores background data from "associated layers"
         supplementary_layer_data = []
 
-        # TODO(jamesgk) maybe create one font at a time to reduce memory usage
-        # TODO: (jany) in the future, return a lazy iterator that builds UFOs
-        #     on demand.
-        self.to_ufo_font_attributes(self.family_name)
-
         # Generate the main (master) layers first.
         for glyph in self.font.glyphs:
             for layer in glyph.layers.values():
@@ -258,44 +295,13 @@ def masters(self):
                 and ".background" not in layer.name
             ):
                 self.bracket_layers.append(layer)
+            elif self.minimal and layer.layerId not in master_layer_ids:
+                continue
             else:
                 ufo_layer = self.to_ufo_layer(glyph, layer)
                 ufo_glyph = ufo_layer.newGlyph(glyph.name)
                 self.to_ufo_glyph(ufo_glyph, layer, layer.parent)
 
-        for master_id, source in self._sources.items():
-            ufo = source.font
-            master = self.font.masters[master_id]
-            if self.propagate_anchors:
-                self.to_ufo_propagate_font_anchors(ufo)
-            for layer in list(ufo.layers):
-                self.to_ufo_layer_lib(master, ufo, layer)
-
-            # to_ufo_custom_params may apply "Replace Features" or "Replace Prefix"
-            # parameters so it requires UFOs have their features set first; at the
-            # same time, to generate a GDEF table we first need to have defined the
-            # glyphOrder, exported the glyphs and propagated anchors from components.
-            self.to_ufo_master_features(ufo, master)
-            self.to_ufo_custom_params(ufo, master)
-
-        if self.write_skipexportglyphs:
-            # Sanitize skip list and write it to both Designspace- and UFO-level lib
-            # keys. The latter is unnecessary when using e.g. the ufo2ft.compile*FromDS`
-            # functions, but the data may take a different path. Writing it everywhere
-            # can save on surprises/logic in other software.
-            skip_export_glyphs = self._designspace.lib.get("public.skipExportGlyphs")
-            if skip_export_glyphs is not None:
-                skip_export_glyphs = sorted(set(skip_export_glyphs))
-                self._designspace.lib["public.skipExportGlyphs"] = skip_export_glyphs
-                for source in self._sources.values():
-                    source.font.lib["public.skipExportGlyphs"] = skip_export_glyphs
-
-        self.to_ufo_groups()
-        self.to_ufo_kerning()
-
-        for source in self._sources.values():
-            yield source.font
-
     @property
     def designspace(self):
         """Get a designspace Document instance that links the masters together

Lib/glyphsLib/builder/glyph.py

@@ -150,10 +150,11 @@ def to_ufo_glyph(self, ufo_glyph, layer, glyph):  # noqa: C901
     else:
         ufo_glyph.width = width
 
-    self.to_ufo_background_image(ufo_glyph, layer)
-    self.to_ufo_guidelines(ufo_glyph, layer)
-    self.to_ufo_glyph_background(ufo_glyph, layer)
-    self.to_ufo_annotations(ufo_glyph, layer)
+    if not self.minimal:
+        self.to_ufo_background_image(ufo_glyph, layer)
+        self.to_ufo_guidelines(ufo_glyph, layer)
+        self.to_ufo_glyph_background(ufo_glyph, layer)
+        self.to_ufo_annotations(ufo_glyph, layer)
     self.to_ufo_hints(ufo_glyph, layer)
     self.to_ufo_glyph_user_data(ufo_font, glyph)
     self.to_ufo_layer_user_data(ufo_glyph, layer)

Lib/glyphsLib/cli.py

@@ -218,6 +218,7 @@ def glyphs2ufo(options):
         store_editor_state=not options.no_store_editor_state,
         write_skipexportglyphs=options.write_public_skip_export_glyphs,
         ufo_module=__import__(options.ufo_module),
+        minimal=False,
     )
 
 

tests/builder/builder_test.py

@@ -885,7 +885,7 @@ def _run_guideline_test(self, data_in, expected):
             guide.angle = guide_data["angle"]
             layer.guides.append(guide)
         glyph.layers.append(layer)
-        ufo = self.to_ufos(font)[0]
+        ufo = self.to_ufos(font, minimal=False)[0]
         self.assertEqual([dict(g) for g in ufo["a"].guidelines], expected)
 
     def test_set_guidelines(self):
@@ -918,7 +918,7 @@ def test_supplementary_layers(self):
         sublayer.width = 0
         sublayer.name = "SubLayer"
         glyph.layers.append(sublayer)
-        ufo = self.to_ufos(font)[0]
+        ufo = self.to_ufos(font, minimal=False)[0]
         self.assertEqual([l.name for l in ufo.layers], ["public.default", "SubLayer"])
 
     def test_duplicate_supplementary_layers(self):
@@ -941,7 +941,7 @@ def test_duplicate_supplementary_layers(self):
         sublayer.name = "SubLayer"
         glyph.layers.append(sublayer)
         with CapturingLogHandler(builder.logger, level="WARNING") as captor:
-            ufo = self.to_ufos(font)[0]
+            ufo = self.to_ufos(font, minimal=False)[0]
 
         self.assertEqual(
             [l.name for l in ufo.layers], ["public.default", "SubLayer", "SubLayer #1"]

tests/builder/components_test.py

@@ -8,7 +8,7 @@
 
 def test_background_component_decompose(datadir):
     font = glyphsLib.GSFont(str(datadir.join("Recursion.glyphs")))
-    ds = to_designspace(font)
+    ds = to_designspace(font, minimal=False)
 
     for source in ds.sources:
         for layer in source.font.layers:
@@ -48,4 +48,4 @@ def test_background_component_decompose_missing(datadir):
     layer.components.append(GSComponent("xxx"))
 
     with pytest.raises(MissingComponentError):
-        to_designspace(font)
+        to_designspace(font, minimal=False)

tests/builder/designspace_gen_test.py

@@ -423,7 +423,7 @@ def test_designspace_generation_bracket_no_export_glyph(datadir, ufo_module):
     font.glyphs["E"].export = False
 
     designspace = to_designspace(
-        font, write_skipexportglyphs=True, ufo_module=ufo_module
+        font, write_skipexportglyphs=True, ufo_module=ufo_module, minimal=False
     )
 
     assert "E" in designspace.lib.get("public.skipExportGlyphs")

tests/builder/lib_and_user_data_test.py

@@ -230,7 +230,7 @@ def test_layer_lib_into_master_user_data(ufo_module):
         "layerLibKey2": "ufo2 layerLibValue2"
     }
 
-    (ufo1, ufo2) = to_ufos(font)
+    (ufo1, ufo2) = to_ufos(font, minimal=False)
 
     assert ufo1.layers["public.default"].lib["layerLibKey1"] == "ufo1 layerLibValue1"
     assert "layerLibKey1" not in ufo1.layers["sketches"].lib
@@ -321,7 +321,7 @@ def test_glif_lib_equivalent_to_layer_user_data(ufo_module):
     assert "glifLibKeyB" not in default_layer.userData.keys()
     assert middleground.userData["glifLibKeyB"] == "glifLibValueB"
 
-    (ufo,) = to_ufos(font)
+    (ufo,) = to_ufos(font, minimal=False)
 
     assert ufo["a"].lib["glifLibKeyA"] == "glifLibValueA"
     assert "glifLibKeyA" not in ufo.layers["middleground"]["a"]

tests/builder/to_glyphs_test.py

@@ -211,7 +211,7 @@ def test_guidelines(ufo_module):
         assert horizontal.position.y == 20
         assert horizontal.angle == 0
 
-    (ufo,) = to_ufos(font)
+    (ufo,) = to_ufos(font, minimal=False)
 
     for obj in [ufo, ufo["a"]]:
         angled, vertical, horizontal = obj.guidelines
@@ -470,7 +470,7 @@ def test_dont_copy_advance_to_the_background_unless_it_was_there(tmpdir, ufo_mod
     saved_font = classes.GSFont(path)
 
     for font in [font, saved_font]:
-        (ufo,) = to_ufos(font)
+        (ufo,) = to_ufos(font, minimal=False)
 
         assert ufo["a"].width == 100
         assert ufo.layers["public.background"]["a"].width == 0