# HG changeset patch
# User Goffi <goffi@goffi.org>
# Date 1553070584 -3600
# Node ID 23d4358803c7d0c18608554cdd8a0decef2c1276
# Parent  89ba66464329557e9c42a850e4bdfcf998d2b51f
widgets_handler: work around the double call of onSlideChange:

with Kivy dev version a95d67f (the one currently used in Python for Android), onSlideChange which is binded on current_slide was called twice with the same widget, resulting in widgets unexpectedly deleted.
This patch fixes it by abording the callback if new_slide is the same as _former_slide, i.e. if the widget is not actually changed.

Started a discussion with upstream Kivy team to check if this is a bug or feature.

diff -r 89ba66464329 -r 23d4358803c7 cagou/core/widgets_handler.py
--- a/cagou/core/widgets_handler.py	Wed Mar 20 09:29:44 2019 +0100
+++ b/cagou/core/widgets_handler.py	Wed Mar 20 09:29:44 2019 +0100
@@ -326,6 +326,11 @@
 
     def onSlideChange(self, handler, new_slide):
         if self._former_slide is not None:
+            if self._former_slide is new_slide:
+                # FIXME: workaround for Kivy a95d67f (and above?), Carousel.current_slide
+                #        binding now calls onSlideChange twice with the same widget (here
+                #        "new_slide"). To be checked with Kivy team.
+                return
             G.host._removeVisibleWidget(self._former_slide)
         self._former_slide = new_slide
         if new_slide is not None: