From e2b16a18a335df2bc4504a838ed33579a9de4825 Mon Sep 17 00:00:00 2001 From: chrox Date: Sat, 16 Mar 2013 00:05:00 +0800 Subject: [PATCH] comments for clamping scroll offsets --- frontend/ui/reader/readerpaging.lua | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/frontend/ui/reader/readerpaging.lua b/frontend/ui/reader/readerpaging.lua index 89cffdff4..99a763564 100644 --- a/frontend/ui/reader/readerpaging.lua +++ b/frontend/ui/reader/readerpaging.lua @@ -359,7 +359,11 @@ function ReaderPaging:onScrollPageRel(diff) x = 0, y = last_page_state.visible_area.h - self.overlap } - -- scroll down offset should always be greater than 0 + -- Scroll down offset should always be greater than 0 + -- otherwise if offset is less than 0 the height of blank area will be + -- larger than 0 even if page area is much larger than visible area, + -- which will trigger the drawing of next page leaving part of current + -- page undrawn. This should also be true for scroll up offset. if offset.y < 0 then offset.y = 0 end local state = self:updateLastPageState(last_page_state, blank_area, offset) --DEBUG("updated state", state)