--[[--
HTML widget (without scroll bars).
--]]
local Device = require("device")
local DrawContext = require("ffi/drawcontext")
local Geom = require("ui/geometry")
local GestureRange = require("ui/gesturerange")
local InputContainer = require("ui/widget/container/inputcontainer")
local Mupdf = require("ffi/mupdf")
local Screen = require("device").screen
local TimeVal = require("ui/timeval")
local logger = require("logger")
local util = require("util")
local HtmlBoxWidget = InputContainer:new{
bb = nil,
dimen = nil,
document = nil,
page_count = 0,
page_number = 1,
hold_start_pos = nil,
hold_start_tv = nil,
html_link_tapped_callback = nil,
}
function HtmlBoxWidget:init()
if Device:isTouchDevice() then
self.ges_events = {
TapText = {
GestureRange:new{
ges = "tap",
range = function() return self.dimen end,
},
},
}
end
if Mupdf.bgr == nil then
Mupdf.bgr = false
if Device:hasBGRFrameBuffer() then
Mupdf.bgr = true
end
end
end
function HtmlBoxWidget:setContent(body, css, default_font_size)
-- fz_set_user_css is tied to the context instead of the document so to easily support multiple
-- HTML dictionaries with different CSS, we embed the stylesheet into the HTML instead of using
-- that function.
local head = ""
if css then
head = string.format("", css)
end
local html = string.format("%s%s", head, body)
-- For some reason in MuPDF
always creates both a line break and an empty line, so we have to
-- simulate the normal
behavior.
-- https://bugs.ghostscript.com/show_bug.cgi?id=698351
html = html:gsub("%
", " ")
local ok
ok, self.document = pcall(Mupdf.openDocumentFromText, html, "html")
if not ok then
-- self.document contains the error
logger.warn("HTML loading error:", self.document)
body = util.htmlToPlainText(body)
body = util.htmlEscape(body)
-- Normally \n would be replaced with
. See the previous comment regarding the bug in MuPDF.
body = body:gsub("\n", " ")
html = string.format("%s%s", head, body)
ok, self.document = pcall(Mupdf.openDocumentFromText, html, "html")
if not ok then
error(self.document)
end
end
self.document:layoutDocument(self.dimen.w, self.dimen.h, default_font_size)
self.page_count = self.document:getPages()
end
function HtmlBoxWidget:_render()
if self.bb then
return
end
-- In pdfdocument.lua, color is activated only at the moment of
-- rendering and then immediately disabled, for safety with kopt.
-- We do the same here.
Mupdf.color = Screen:isColorEnabled()
local page = self.document:openPage(self.page_number)
local dc = DrawContext.new()
self.bb = page:draw_new(dc, self.dimen.w, self.dimen.h, 0, 0)
page:close()
Mupdf.color = false
end
function HtmlBoxWidget:getSize()
return self.dimen
end
function HtmlBoxWidget:paintTo(bb, x, y)
self.dimen.x = x
self.dimen.y = y
self:_render()
local size = self:getSize()
bb:blitFrom(self.bb, x, y, 0, 0, size.w, size.h)
end
function HtmlBoxWidget:freeBb()
if self.bb and self.bb.free then
self.bb:free()
end
self.bb = nil
end
-- This will normally be called by our WidgetContainer:free()
-- But it SHOULD explicitly be called if we are getting replaced
-- (ie: in some other widget's update()), to not leak memory with
-- BlitBuffer zombies
function HtmlBoxWidget:free()
self:freeBb()
if self.document then
self.document:close()
self.document = nil
end
end
function HtmlBoxWidget:onCloseWidget()
-- free when UIManager:close() was called
self:free()
end
function HtmlBoxWidget:getPosFromAbsPos(abs_pos)
local pos = Geom:new{
x = abs_pos.x - self.dimen.x,
y = abs_pos.y - self.dimen.y,
}
-- check if the coordinates are actually inside our area
if pos.x < 0 or pos.x >= self.dimen.w or pos.y < 0 or pos.y >= self.dimen.h then
return nil
end
return pos
end
function HtmlBoxWidget:onHoldStartText(_, ges)
self.hold_start_pos = self:getPosFromAbsPos(ges.pos)
if not self.hold_start_pos then
return false -- let event be processed by other widgets
end
self.hold_start_tv = TimeVal.now()
return true
end
function HtmlBoxWidget:onHoldPan(_, ges)
-- We don't highlight the currently selected text, but just let this
-- event pop up if we are not currently selecting text
if not self.hold_start_pos then
return false
end
return true
end
function HtmlBoxWidget:getSelectedText(lines, start_pos, end_pos)
local found_start = false
local words = {}
for _, line in pairs(lines) do
for _, w in pairs(line) do
if type(w) == 'table' then
if not found_start then
if start_pos.x >= w.x0 and start_pos.x < w.x1 and start_pos.y >= w.y0 and start_pos.y < w.y1 then
found_start = true
elseif end_pos.x >= w.x0 and end_pos.x < w.x1 and end_pos.y >= w.y0 and end_pos.y < w.y1 then
-- We found end_pos before start_pos, switch them
found_start = true
start_pos, end_pos = end_pos, start_pos
end
end
if found_start then
table.insert(words, w.word)
-- Found the end.
if end_pos.x >= w.x0 and end_pos.x < w.x1 and end_pos.y >= w.y0 and end_pos.y < w.y1 then
return words
end
end
end
end
end
return words
end
function HtmlBoxWidget:onHoldReleaseText(callback, ges)
if not callback then
return false
end
-- check we have seen a HoldStart event
if not self.hold_start_pos then
return false
end
local start_pos = self.hold_start_pos
self.hold_start_pos = nil
local end_pos = self:getPosFromAbsPos(ges.pos)
if not end_pos then
return false
end
local hold_duration = TimeVal.now() - self.hold_start_tv
hold_duration = hold_duration.sec + (hold_duration.usec/1000000)
local page = self.document:openPage(self.page_number)
local lines = page:getPageText()
page:close()
local words = self:getSelectedText(lines, start_pos, end_pos)
local selected_text = table.concat(words, " ")
callback(selected_text, hold_duration)
return true
end
function HtmlBoxWidget:getLinkByPosition(pos)
local page = self.document:openPage(self.page_number)
local links = page:getPageLinks()
page:close()
for _, link in pairs(links) do
if pos.x >= link.x0 and pos.x < link.x1 and pos.y >= link.y0 and pos.y < link.y1 then
return link
end
end
end
function HtmlBoxWidget:onTapText(arg, ges)
if G_reader_settings:isFalse("tap_to_follow_links") then
return
end
if self.html_link_tapped_callback then
local pos = self:getPosFromAbsPos(ges.pos)
if pos then
local link = self:getLinkByPosition(pos)
if link then
self.html_link_tapped_callback(link)
return true
end
end
end
end
return HtmlBoxWidget