textinput: avoid pygame error when the text is too large. use dichotomy to found the maximum characters we can handle in the line. most of the time, the line will be re-arranged in the next layout, except if no space are found. closes #420

kivy/uix/textinput.py

@@ -877,9 +877,35 @@ class TextInput(Widget):
         kw = self._get_line_options()
         cid = '%s\0%s' % (ntext, str(kw))
         texture = Cache.get('textinput.label', cid)
+
         if not texture:
-            label = Label(text=ntext, **kw)
-            label.refresh()
+            # FIXME right now, we can't render very long line...
+            # if we move on "VBO" version as fallback, we won't need to do this.
+            # try to found the maximum text we can handle
+            label = None
+            label_len = len(ntext)
+            ld = None
+            while True:
+                try:
+                    label = Label(text=ntext[:label_len], **kw)
+                    label.refresh()
+                    if ld is not None and ld > 2:
+                        ld = int(ld / 2)
+                        label_len += ld
+                    else:
+                        break
+                except:
+                    # exception happen when we tried to render the text
+                    # reduce it...
+                    if ld is None:
+                        ld = len(ntext)
+                    ld = int(ld / 2)
+                    if ld < 2 and label_len:
+                        label_len -= 1
+                    label_len -= ld
+                    continue
+
+            # ok, we found it.
             texture = label.texture
             Cache.append('textinput.label', cid, texture)
         return texture