added support for multiline text drawing

PIL/ImageDraw.py

@@ -257,6 +257,9 @@ def rectangle(self, xy, fill=None, outline=None):
     # Draw text.
 
     def text(self, xy, text, fill=None, font=None, anchor=None):
+        if "\n" in text:
+            return self.multiline_text(xy, text, fill, font, anchor)
+
         ink, fill = self._getink(fill)
         if font is None:
             font = self.getfont()
@@ -273,10 +276,49 @@ def text(self, xy, text, fill=None, font=None, anchor=None):
                     mask = font.getmask(text)
             self.draw.draw_bitmap(xy, mask, ink)
 
+    def multiline_text(self, xy, text, fill=None, font=None, anchor=None,
+            spacing=0, align="left"):
+        widths, heights = [], []
+        max_width = 0
+        lines = text.split("\n")
+        for line in lines:
+            line_width, line_height = self.textsize(line, font)
+            widths.append(line_width)
+            max_width = max(max_width, line_width)
+            heights.append(line_height)
+        left, top = xy
+        for idx, line in enumerate(lines):
+            if align == "left":
+                pass # left = x
+            elif align == "center":
+                left += (max_width - widths[idx]) / 2.0
+            elif align == "right":
+                left += (max_width - widths[idx])
+            else:
+                assert False, 'align must be either "left", "center" or "right"'
+            self.text((left, top), 
+                line, fill, font, anchor)
+            top += heights[idx] + spacing
+            left = xy[0]
+
+    def multiline_textsize(self, text, font=None, spacing=0):
+        max_width = 0
+        height = 0
+        lines = text.split("\n")
+        for line in lines:
+            line_width, line_height = self.textsize(line, font)
+            height += line_height + spacing
+            max_width = max(max_width, line_width)
+        return max_width, height
+
+
     ##
     # Get the size of a given string, in pixels.
 
     def textsize(self, text, font=None):
+        if "\n" in text:
+            return multiline_textsize(text, font)
+
         if font is None:
             font = self.getfont()
         return font.getsize(text)