[Snippets/print-json.py] Add using the visitor module

Snippets/print-json.py

@@ -0,0 +1,106 @@
+import fontTools.ttLib as ttLib
+from fontTools.ttLib.ttVisitor import TTVisitor
+from fontTools.misc.textTools import Tag
+
+
+class JsonVisitor(TTVisitor):
+
+    def _open(self, s):
+        print(s, file=self.file)
+        self._indent += self.indent
+
+    def _close(self, s):
+        self._indent = self._indent[:-len(self.indent)]
+        print("%s%s," % (self._indent, s), file=self.file)
+
+    def __init__(self, file, indent="  "):
+        self.file = file
+        self.indent = indent
+        self._indent = ""
+
+    def visitObject(self, obj):
+        self._open("{")
+        super().visitObject(obj)
+        print('%s"type": "%s"' % (self._indent, obj.__class__.__name__), file=self.file)
+        self._close("}")
+
+    def visitAttr(self, obj, attr, value):
+        print('%s"%s": ' % (self._indent, attr), end="", file=self.file)
+        self.visit(value)
+
+    def visitList(self, obj, *args, **kwargs):
+        self._open("[")
+        for value in obj:
+            print(self._indent, end="", file=self.file)
+            self.visit(value, *args, **kwargs)
+        self._close("]")
+
+    def visitDict(self, obj, *args, **kwargs):
+        self._open("{")
+        for key, value in obj.items():
+            print('%s"%s": ' % (self._indent, key), end="", file=self.file)
+            self.visit(value, *args, **kwargs)
+        self._close("}")
+
+    def visitLeaf(self, obj):
+        if isinstance(obj, tuple):
+            obj = list(obj)
+
+        if isinstance(obj, bytes):
+            s = repr(obj)
+            s = s[1:]
+        else:
+            s = repr(obj)
+
+        if s[0] == "'":
+            s = '"' + s[1:-1] + '"'
+
+        print("%s," % s, file=self.file)
+
+
+@JsonVisitor.register(ttLib.TTFont)
+def visit(self, font):
+    if hasattr(visitor, "font"):
+        return False
+    visitor.font = font
+
+    self._open("{")
+    for tag in font.keys():
+        print('%s"%s": ' % (self._indent, tag), end="", file=self.file)
+        visitor.visit(font[tag])
+    self._close("}")
+
+    del visitor.font
+    return False
+
+
+@JsonVisitor.register_attr(ttLib.getTableClass("glyf"), "glyphOrder")
+def visit(visitor, obj, attr, value):
+    return False
+
+
+@JsonVisitor.register(ttLib.getTableModule("glyf").GlyphCoordinates)
+def visit(self, obj):
+    self.visitList(obj)
+    return False
+
+
+@JsonVisitor.register(Tag)
+def visit(self, obj):
+    print('"%s",' % str(obj), file=self.file)
+    return False
+
+
+if __name__ == "__main__":
+
+    from fontTools.ttLib import TTFont
+    import sys
+
+    if len(sys.argv) != 2:
+        print("usage: print-json.py font")
+        sys.exit()
+
+    font = TTFont(sys.argv[1])
+
+    visitor = JsonVisitor(sys.stdout)
+    visitor.visit(font)