[PDF] footer cuts off bottom of page in page mode

[yparitcher]

• KOReader version: v2019.11-20-g15fe0fef_2019-11-18
• Device: emulator

Issue

regression symptom of #3870

- return self.footer_text:getSize().h
+ return self.footer_content:getSize().h

by changing the effective footer height from 24 to 15

when setting the offset to half the non visible area (ie: the space subtracted because of the footer)

koreader/frontend/apps/reader/modules/readerview.lua

Lines 595 to 598 in 15fe0fe

	self.state.offset = Geom:new{x = 0, y = 0}
	if self.dimen.h > self.visible_area.h then
	self.state.offset.y = (self.dimen.h - self.visible_area.h) / 2
	end

causes the footer to actually cover the pdf by half its height ~ 7, however when the footer height was supposedly 24 of which half is 12 the extra 3 pixels were not noticed.

the underlying cause is not taking the footer into account when calculating the offset.
however if the offset is lessened when the footer is present the footer does not properly update on toggle.

screenshots from the paper.pdf in the test submodule, page 19
the calculation is cut off

when changing

    if self.dimen.h > self.visible_area.h then
-        self.state.offset.y = (self.dimen.h - self.visible_area.h) / 2
+        self.state.offset.y = ((self.dimen.h - self.visible_area.h)- self.ui.view.footer:getHeight()) / 2
    end

the calculation is visible

and when tapping on the footer to hide it, only the sides of the footer are hidden

[NiLuJe]

IIRC, there's a (very, very) long-standing issue with the footer clobbering the bottom of PDF pages. There might even be an open issue about it (if there is, it's an old one).

[yparitcher]

IIRC, there's a (very, very) long-standing issue with the footer clobbering the bottom of PDF pages. There might even be an open issue about it (if there is, it's an old one).

that would be #2072 fixed by #2079
however that only hid the symptoms.

this only happens when the page is bound by height for example if the zoom mode is contentheight.

i would like to fix it, however i am having a vey hard time understanding the code.

[yparitcher]

i have a partial fix in yparitcher@ad126f4

however when doing so the onTapFooter does not properly hide the footer like so:

if the footer was toggled on on the current page, it will also toggle off, even when panning in the middle

if the footer was toggled on on a different page, it will not toggle off (visibly) until the page is turned. (panning does not help)

[yparitcher]

i got to the root of the issue, PR on the way. one question, is it better to have the margin code paint under the footer in order that when tapping on the footer (to disable it) the space is cleared. this to me is bit of a hack, this can be seen here: yparitcher@e04b7c8 or should i have the whole page recalculated on footer tap, which will cause the view to reset to the top of the page, even when panned to the middle.

[Frenzie]

view … reset to the top of the page, even when panned

/twitchtwitch

That would annoy me immensely, and probably not just me. ;-)

this to me is bit of a hack

Depends on how you use the footer, I suppose. I'd say not painting under the overlay sounds like premature optimization with a lot of extra effort involved to make it work.