renun/koreader
1
0
Fork 0
mirror of https://github.com/koreader/koreader.git synced 2025-08-10 00:52:38 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Show vertical marker at original position when back from link (#3669)

Browse Source 
ReaderLink: make all links be a table (they were a table for PDF,
but a string for CRE) for clearer code. Also have location_stack
store them as tables, with additional properties.
Get original position of link source (and verify it is valid)
so we can show a marker there.

Also:
Hold on "Go back to previous location" to clear location stack.
Resists "Swipe to go back" when previous locations stack has just
become empty, and show a notification.
Fix wrong links with Swipe to follow nearest link on PDF documents.
This commit is contained in:
poire-z
2018-02-09 17:06:16 +01:00
committed by Frans de Jonge
parent e7be8ef34d
commit 59496c1d46
3 changed files with 209 additions and 50 deletions
Download Patch File Download Diff File Expand all files Collapse all files

190
frontend/apps/reader/modules/readerlink.lua
View File

@@ -2,12 +2,14 @@
ReaderLink is an abstraction for document-specific link interfaces.
]]
local ConfirmBox = require("ui/widget/confirmbox")
local Device = require("device")
local Event = require("ui/event")
local Geom = require("ui/geometry")
local GestureRange = require("ui/gesturerange")
local InputContainer = require("ui/widget/container/inputcontainer")
local LinkBox = require("ui/widget/linkbox")
local Notification = require("ui/widget/notification")
local UIManager = require("ui/uimanager")
local logger = require("logger")
local _ = require("gettext")
@@ -139,9 +141,37 @@ function ReaderLink:addToMainMenu(menu_items)
text = _("Go back to previous location"),
enabled_func = function() return #self.location_stack > 0 end,
callback = function() self:onGoBackLink() end,
hold_callback = function() UIManager:show(ConfirmBox:new{
text = _("Clear location history?"),
ok_text = _("Clear"),
ok_callback = function()
self.location_stack = {}
end,
})
end,
}
end
--- Check if a xpointer to <a> node really points to itself
function ReaderLink:isXpointerCoherent(a_xpointer)
-- Get screen coordinates of xpointer
local doc_margins = self.ui.document._document:getPageMargins()
local doc_y, doc_x = self.ui.document:getPosFromXPointer(a_xpointer)
local top_y = self.ui.document:getCurrentPos()
-- (strange, but using doc_margins.top is accurate even in scroll mode)
local screen_y = doc_y - top_y + doc_margins["top"]
local screen_x = doc_x + doc_margins["left"]
-- Get again link and a_xpointer from this position
local re_link_xpointer, re_a_xpointer = self.ui.document:getLinkFromPosition({x = screen_x, y = screen_y}) -- luacheck: no unused
-- We should get the same a_xpointer. If not, crengine has messed up
-- and we should not trust this xpointer to get back to this link.
if re_a_xpointer ~= a_xpointer then
logger.info("not coherent a_xpointer:", a_xpointer)
return false
end
return true
end
--- Gets link from gesture.
-- `Document:getLinkFromPosition()` behaves differently depending on
-- document type, so this function provides a wrapper.
@@ -152,35 +182,56 @@ function ReaderLink:getLinkFromGes(ges)
-- link box in native page
local link, lbox = self.ui.document:getLinkFromPosition(pos.page, pos)
if link and lbox then
return link, lbox, pos
return {
link = link,
lbox = lbox,
pos = pos,
}
end
end
else
local link = self.ui.document:getLinkFromPosition(ges.pos)
if link ~= "" then
return link
local link_xpointer, a_xpointer = self.ui.document:getLinkFromPosition(ges.pos)
logger.dbg("getLinkFromPosition link_xpointer:", link_xpointer)
logger.dbg("getLinkFromPosition a_xpointer:", a_xpointer)
-- On some documents, crengine may sometimes give a wrong a_xpointer
-- (in some Wikipedia saved as EPUB, it would point to some other <A>
-- element in the same paragraph). If followed then back, we could get
-- to a different page. So, we check here how valid it is, and if not,
-- we just discard it so that addCurrentLocationToStack() is used.
if a_xpointer and not self:isXpointerCoherent(a_xpointer) then
a_xpointer = nil
end
if link_xpointer ~= "" then
-- This link's target xpointer is more precise than a classic
-- xpointer to top of a page: we can show a marker at its
-- y-position in target page
return {
xpointer = link_xpointer,
marker_xpointer = link_xpointer,
from_xpointer = a_xpointer,
}
end
end
end
--- Highlights a linkbox if available and goes to it.
function ReaderLink:showLinkBox(link, lbox, pos)
if link and lbox then
function ReaderLink:showLinkBox(link)
if link and link.lbox then -- pdfdocument
-- screen box that holds the link
local sbox = self.view:pageToScreenTransform(pos.page,
self.ui.document:nativeToPageRectTransform(pos.page, lbox))
local sbox = self.view:pageToScreenTransform(link.pos.page,
self.ui.document:nativeToPageRectTransform(link.pos.page, link.lbox))
if sbox then
UIManager:show(LinkBox:new{
box = sbox,
timeout = FOLLOW_LINK_TIMEOUT,
callback = function() self:onGotoLink(link) end
callback = function() self:onGotoLink(link.link) end
})
return true
end
else
if link ~= "" then
return self:onGotoLink(link)
end
elseif link and link.xpointer ~= "" then -- credocument
return self:onGotoLink(link)
end
end
@@ -193,9 +244,9 @@ end
function ReaderLink:onTap(_, ges)
if not isTapToFollowLinksOn() then return end
local link, lbox, pos = self:getLinkFromGes(ges)
local link = self:getLinkFromGes(ges)
if link then
return self:showLinkBox(link, lbox, pos)
return self:showLinkBox(link)
end
end
@@ -204,7 +255,9 @@ function ReaderLink:addCurrentLocationToStack()
if self.ui.document.info.has_pages then
table.insert(self.location_stack, self.ui.paging:getBookLocation())
else
table.insert(self.location_stack, self.ui.rolling:getBookLocation())
table.insert(self.location_stack, {
xpointer = self.ui.rolling:getBookLocation(),
})
end
end
@@ -229,24 +282,47 @@ function ReaderLink:onGotoLink(link, neglect_current_location)
-- If the XPointer does not exist (or is a full url), we will jump to page 1
-- Best to check that this link exists in document with the following,
-- which accepts both of the above legitimate xpointer as input.
if self.ui.document:isXPointerInDocument(link) then
if self.ui.document:isXPointerInDocument(link.xpointer) then
logger.dbg("Internal link:", link)
if not neglect_current_location then
self:addCurrentLocationToStack()
if link.from_xpointer then
-- We have a more precise xpointer than the xpointer to top of
-- current page that addCurrentLocationToStack() would give, and
-- we may be able to show a marker when back
local saved_location
if self.view.view_mode == "scroll" then
-- In scroll mode, we still use the top of page as the
-- xpointer to go back to, so we get back to the same view.
-- We can still show the marker at the link position
saved_location = {
xpointer = self.ui.rolling:getBookLocation(),
marker_xpointer = link.from_xpointer,
}
else
-- In page mode, we use the same for go to and for marker,
-- as 'page mode' ensures we get back to the same view.
saved_location = {
xpointer = link.from_xpointer,
marker_xpointer = link.from_xpointer,
}
end
table.insert(self.location_stack, saved_location)
else
self:addCurrentLocationToStack()
end
end
self.ui:handleEvent(Event:new("GotoXPointer", link))
self.ui:handleEvent(Event:new("GotoXPointer", link.xpointer, link.marker_xpointer))
return true
end
end
logger.dbg("External link:", link)
-- Check if it is a wikipedia link
local wiki_lang, wiki_page = link:match([[https?://([^%.]+).wikipedia.org/wiki/([^/]+)]])
local wiki_lang, wiki_page = link.xpointer:match([[https?://([^%.]+).wikipedia.org/wiki/([^/]+)]])
if wiki_lang and wiki_page then
logger.dbg("Wikipedia link:", wiki_lang, wiki_page)
-- Ask for user confirmation before launching lookup (on a
-- wikipedia page saved as epub, full of wikipedia links, it's
-- too easy to click on links when wanting to change page...)
local ConfirmBox = require("ui/widget/confirmbox")
UIManager:show(ConfirmBox:new{
text = T(_("Would you like to read this Wikipedia %1 article?\n\n%2\n"), wiki_lang:upper(), wiki_page:gsub("_", " ")),
ok_callback = function()
@@ -256,11 +332,10 @@ function ReaderLink:onGotoLink(link, neglect_current_location)
end
})
else
-- local Notification = require("ui/widget/notification")
local InfoMessage = require("ui/widget/infomessage")
UIManager:show(InfoMessage:new{
text = T(_("Invalid or external link:\n%1"), link),
timeout = 1.0,
text = T(_("Invalid or external link:\n%1"), link.xpointer),
-- no timeout to allow user to type that link in his web browser
})
end
-- don't propagate, user will notice and tap elsewhere if he wants to change page
@@ -271,15 +346,32 @@ end
function ReaderLink:onGoBackLink()
local saved_location = table.remove(self.location_stack)
if saved_location then
logger.dbg("GoBack: restoring:", saved_location)
self.ui:handleEvent(Event:new('RestoreBookLocation', saved_location))
return true
end
end
function ReaderLink:onSwipe(_, ges)
function ReaderLink:onSwipe(arg, ges)
if ges.direction == "east" then
if isSwipeToGoBackEnabled() then
return self:onGoBackLink()
if #self.location_stack > 0 then
-- Remember if location stack is going to be empty, so we
-- can stop the propagation of next swipe back: so the user
-- knows it is empty and that next swipe back will get him
-- to previous page (and not to previous location)
self.swipe_back_resist = #self.location_stack == 1
return self:onGoBackLink()
elseif self.swipe_back_resist then
self.swipe_back_resist = false
-- Make that gesture don't do anything, and show a Notification
-- so the user knows why
UIManager:show(Notification:new{
text = _("Previous locations stack is empty"),
timeout = 1.0,
})
return true
end
end
elseif ges.direction == "west" then
local ret = false
@@ -320,7 +412,7 @@ function ReaderLink:onGoToPageLink(ges, use_page_first_link)
-- ["x0"] = 97,
-- ["page"] = 347
-- },
local pos_x, pos_y = ges.pos.x, ges.pos.y
local pos_x, pos_y = pos.x, pos.y
local shortest_dist = nil
local first_y0 = nil
for _, link in ipairs(links) do
@@ -367,7 +459,11 @@ function ReaderLink:onGoToPageLink(ges, use_page_first_link)
-- ["end_y"] = 1201,
-- ["start_x"] = 352,
-- ["start_y"] = 1201
-- ["a_xpointer"] = "/body/DocFragment/body/div/p[12]/sup[3]/a[3].0",
-- },
-- Note: with some documents and some links, crengine may give wrong
-- coordinates, and our code below may miss or give the wrong first
-- or nearest link...
local pos_x, pos_y = ges.pos.x, ges.pos.y
local shortest_dist = nil
local first_start_y = nil
@@ -377,7 +473,7 @@ function ReaderLink:onGoToPageLink(ges, use_page_first_link)
-- links may not be in the order they are in the page, so let's
-- find the one with the smallest start_y.
if first_start_y == nil or link["start_y"] < first_start_y then
selected_link = link["section"]
selected_link = link
first_start_y = link["start_y"]
end
else
@@ -385,9 +481,7 @@ function ReaderLink:onGoToPageLink(ges, use_page_first_link)
local end_dist = math.pow(link.end_x - pos_x, 2) + math.pow(link.end_y - pos_y, 2)
local min_dist = math.min(start_dist, end_dist)
if shortest_dist == nil or min_dist < shortest_dist then
-- onGotoLink()'s GotoXPointer event needs
-- the "section" value
selected_link = link["section"]
selected_link = link
shortest_dist = min_dist
end
end
@@ -398,6 +492,24 @@ function ReaderLink:onGoToPageLink(ges, use_page_first_link)
-- and we'll find them highlighted when back from link.
-- So let's clear them now.
self.ui.document:clearSelection()
-- (Comment out previous line to visually see which links on the
-- page are not coherent: those not highlighted)
if selected_link then
logger.dbg("original selected_link", selected_link)
-- Make it a link as expected by onGotoLink
selected_link = {
xpointer = selected_link["section"],
marker_xpointer = selected_link["section"],
from_xpointer = selected_link["a_xpointer"],
}
logger.dbg("selected_link", selected_link)
-- Check from_xpointer is coherent, and unset it if not
if selected_link.from_xpointer and not self:isXpointerCoherent(selected_link.from_xpointer) then
selected_link.from_xpointer = nil
end
end
end
if selected_link then
return self:onGotoLink(selected_link)
@@ -416,9 +528,19 @@ function ReaderLink:onGoToLatestBookmark(ges)
fake_link.page = latest_bookmark.page - 1
return self:onGotoLink(fake_link)
else
-- self:onGotoLink() needs a xpointer, that we find
-- as the bookmark page attribute
return self:onGotoLink(latest_bookmark.page)
-- Make it a link as expected by onGotoLink
local link
if latest_bookmark.pos0 then -- text highlighted, precise xpointer
link = {
xpointer = latest_bookmark.pos0,
marker_xpointer = latest_bookmark.pos0,
}
else -- page bookmarked, 'page' is a xpointer to top of page
link = {
xpointer = latest_bookmark.page,
}
end
return self:onGotoLink(link)
end
end
end