2
0
mirror of https://github.com/koreader/koreader synced 2024-11-04 12:00:25 +00:00
koreader/frontend/ui/widget/textboxwidget.lua

925 lines
38 KiB
Lua

--[[--
A TextWidget that handles long text wrapping
Example:
local Foo = TextBoxWidget:new{
face = Font:getFace("cfont", 25),
text = 'We can show multiple lines.\nFoo.\nBar.',
-- width = Screen:getWidth()*2/3,
}
UIManager:show(Foo)
]]
local Blitbuffer = require("ffi/blitbuffer")
local Device = require("device")
local Font = require("ui/font")
local FrameContainer = require("ui/widget/container/framecontainer")
local Geom = require("ui/geometry")
local GestureRange = require("ui/gesturerange")
local InputContainer = require("ui/widget/container/inputcontainer")
local LineWidget = require("ui/widget/linewidget")
local RenderText = require("ui/rendertext")
local RightContainer = require("ui/widget/container/rightcontainer")
local Size = require("ui/size")
local TextWidget = require("ui/widget/textwidget")
local TimeVal = require("ui/timeval")
local UIManager = require("ui/uimanager")
local Math = require("optmath")
local logger = require("logger")
local util = require("util")
local Screen = require("device").screen
local TextBoxWidget = InputContainer:new{
text = nil,
charlist = nil,
charpos = nil,
char_width_list = nil, -- list of widths of the chars in `charlist`.
vertical_string_list = nil,
editable = false, -- Editable flag for whether drawing the cursor or not.
justified = false, -- Should text be justified (spaces widened to fill width)
alignment = "left", -- or "center", "right"
cursor_line = nil, -- LineWidget to draw the vertical cursor.
face = nil,
bold = nil,
line_height = 0.3, -- in em
fgcolor = Blitbuffer.COLOR_BLACK,
width = Screen:scaleBySize(400), -- in pixels
height = nil, -- nil value indicates unscrollable text widget
virtual_line_num = 1, -- used by scroll bar
_bb = nil,
-- We can provide a list of images: each image will be displayed on each
-- scrolled page, in its top right corner (if more images than pages, remaining
-- images will not be displayed at all - if more pages than images, remaining
-- pages won't have any image).
-- Each 'image' is a table with the following keys:
-- width width of small image displayed by us
-- height height of small image displayed by us
-- bb blitbuffer of small image, may be initially nil
-- optional:
-- hi_width same as previous for a high-resolution version of the
-- hi_height image, to be displayed by ImageViewer when Hold on
-- hi_bb the low-resolution image
-- title ImageViewer title
-- caption ImageViewer caption
--
-- load_bb_func function called (with one arg: false to load 'bb', true to load 'hi_bb)
-- when bb or hi_bb is nil: its job is to load/build bb or hi_bb.
-- The page will refresh itself when load_bb_func returns.
images = nil, -- list of such images
line_num_to_image = nil, -- will be filled by self:_splitCharWidthList()
image_padding_left = Screen:scaleBySize(10),
image_padding_bottom = Screen:scaleBySize(3),
image_alt_face = Font:getFace("xx_smallinfofont"),
image_alt_fgcolor = Blitbuffer.COLOR_BLACK,
}
function TextBoxWidget:init()
self.line_height_px = (1 + self.line_height) * self.face.size
self.cursor_line = LineWidget:new{
dimen = Geom:new{
w = Size.line.medium,
h = self.line_height_px,
}
}
self:_evalCharWidthList()
self:_splitCharWidthList()
if self.height == nil then
self:_renderText(1, #self.vertical_string_list)
else
-- luajit may segfault if we were provided with a negative height
if self.height < 0 then
self.height = 0
end
self:_renderText(1, self:getVisLineCount())
end
if self.editable then
local x, y
x, y = self:_findCharPos()
self.cursor_line:paintTo(self._bb, x, y)
end
self.dimen = Geom:new(self:getSize())
if Device:isTouchDevice() then
self.ges_events = {
TapImage = {
GestureRange:new{
ges = "tap",
range = function() return self.dimen end,
},
},
}
end
end
function TextBoxWidget:unfocus()
self.editable = false
self:init()
end
function TextBoxWidget:focus()
self.editable = true
self:init()
end
-- Split `self.text` into `self.charlist` and evaluate the width of each char in it.
function TextBoxWidget:_evalCharWidthList()
if self.charlist == nil then
self.charlist = util.splitToChars(self.text)
self.charpos = #self.charlist + 1
end
self.char_width_list = {}
-- use a cache to avoid many calls to RenderText:sizeUtf8Text()
local char_width_cache = {}
for _, v in ipairs(self.charlist) do
local w = char_width_cache[v]
if w == nil then
w = RenderText:sizeUtf8Text(0, Screen:getWidth(), self.face, v, true, self.bold).x
char_width_cache[v] = w
end
table.insert(self.char_width_list, {char = v, width = w, pad = 0})
-- pad will be updated if we do text justification
end
end
-- Split the text into logical lines to fit into the text box.
function TextBoxWidget:_splitCharWidthList()
self.vertical_string_list = {}
local idx = 1
local size = #self.char_width_list
local ln = 1
local offset, cur_line_width, cur_line_text
local lines_per_page
if self.height then
lines_per_page = self:getVisLineCount()
end
local image_num = 0
local targeted_width = self.width
local image_lines_remaining = 0
while idx <= size do
-- Every scrolled page, we want to add the next (if any) image at its top right
-- (if not scrollable, we will display only the first image)
-- We need to make shorter lines and leave room for the image
if self.images and #self.images > 0 then
if self.line_num_to_image == nil then
self.line_num_to_image = {}
end
if (lines_per_page and ln % lines_per_page == 1) -- first line of a scrolled page
or (lines_per_page == nil and ln == 1) then -- first line if not scrollabled
image_num = image_num + 1
if image_num <= #self.images then
local image = self.images[image_num]
self.line_num_to_image[ln] = image
-- Resize image if really too big: bb will be cropped if already there,
-- but if loaded later with load_bb_func, load_bb_func may resize it
-- to the width and height we have updated here.
if image.width > self.width / 2 then
image.height = math.floor(image.height * (self.width / 2 / image.width))
image.width = math.floor(self.width / 2)
end
if image.height > self.height / 2 then
image.width = math.floor(image.width * (self.height / 2 / image.height))
image.height = math.floor(self.height / 2)
end
targeted_width = self.width - image.width - self.image_padding_left
image_lines_remaining = math.ceil((image.height + self.image_padding_bottom)/self.line_height_px)
end
end
if image_lines_remaining > 0 then
image_lines_remaining = image_lines_remaining - 1
else
targeted_width = self.width -- text can now use full width
end
end
offset = idx
-- Appending chars until the accumulated width exceeds `targeted_width`,
-- or a newline occurs, or no more chars to consume.
cur_line_width = 0
local hard_newline = false
local char_pads = nil
while idx <= size do
if self.char_width_list[idx].char == "\n" then
hard_newline = true
break
end
cur_line_width = cur_line_width + self.char_width_list[idx].width
if cur_line_width > targeted_width then break else idx = idx + 1 end
end
if cur_line_width <= targeted_width then -- a hard newline or end of string
cur_line_text = table.concat(self.charlist, "", offset, idx - 1)
else
-- Backtrack the string until the length fit into one line.
-- We'll give next and prev chars to isSplittable() for a wiser decision
local c = self.char_width_list[idx].char
local next_c = idx+1 <= size and self.char_width_list[idx+1].char or false
local prev_c = idx-1 >= 1 and self.char_width_list[idx-1].char or false
local adjusted_idx = idx
local adjusted_width = cur_line_width
while adjusted_idx > offset and not util.isSplittable(c, next_c, prev_c) do
adjusted_width = adjusted_width - self.char_width_list[adjusted_idx].width
adjusted_idx = adjusted_idx - 1
next_c = c
c = prev_c
prev_c = adjusted_idx-1 >= 1 and self.char_width_list[adjusted_idx-1].char or false
end
if adjusted_idx == offset or adjusted_idx == idx then
-- either a very long english word ocuppying more than one line,
-- or the excessive char is itself splittable:
-- we let that excessive char for next line
if adjusted_idx == offset then -- let the fact a long word was splitted be known
self.has_split_inside_word = true
end
cur_line_text = table.concat(self.charlist, "", offset, idx - 1)
cur_line_width = cur_line_width - self.char_width_list[idx].width
elseif c == " " then
-- we backtracked and we're below max width, but the last char
-- is a space, we can ignore it
cur_line_text = table.concat(self.charlist, "", offset, adjusted_idx - 1)
cur_line_width = adjusted_width - self.char_width_list[adjusted_idx].width
idx = adjusted_idx + 1
else
-- we backtracked and we're below max width, we can leave the
-- splittable char on this line
cur_line_text = table.concat(self.charlist, "", offset, adjusted_idx)
cur_line_width = adjusted_width
idx = adjusted_idx + 1
end
if self.justified then
-- this line was splitted and can be justified
-- we build a list of char_pads, pixels to add to some chars to make the
-- whole line justified
local fill_width = targeted_width - cur_line_width
if fill_width > 0 then
local _, nbspaces = string.gsub(cur_line_text, " ", "")
if nbspaces > 0 then
-- width added to all spaces
local space_add_w = math.floor(fill_width / nbspaces)
-- nb of spaces to which we'll add 1 more pixel
local space_add1_nb = fill_width - space_add_w * nbspaces
char_pads = {}
for cidx = offset, idx-1 do
local pad = 0
if self.char_width_list[cidx].char == " " then
pad = space_add_w
if space_add1_nb > 0 then
pad = pad + 1
space_add1_nb = space_add1_nb - 1
end
-- Update pad info, help for hold position accuracy
self.char_width_list[cidx].pad = pad
end
table.insert(char_pads, pad)
end
else
-- very long word, or CJK text with no space
-- pad first chars with 1 pixel
char_pads = {}
for cidx = offset, idx-1 do
local pad = 0
if fill_width > 0 then
pad = 1
fill_width = fill_width - 1
-- Update pad info, help for hold position accuracy
self.char_width_list[cidx].pad = pad
end
table.insert(char_pads, pad)
end
end
end
end
end -- endif cur_line_width > targeted_width
if cur_line_width < 0 then break end
self.vertical_string_list[ln] = {
text = cur_line_text,
offset = offset,
width = cur_line_width,
char_pads = char_pads,
}
if hard_newline then
idx = idx + 1
-- FIXME: reuse newline entry
self.vertical_string_list[ln+1] = {text = "", offset = idx, width = 0}
else
-- If next char is a space, discard it so it does not become
-- an ugly leading space on the next line
if idx <= size and self.char_width_list[idx].char == " " then
idx = idx + 1
end
end
ln = ln + 1
-- Make sure `idx` point to the next char to be processed in the next loop.
end
end
function TextBoxWidget:_renderText(start_row_idx, end_row_idx)
local font_height = self.face.size
if start_row_idx < 1 then start_row_idx = 1 end
if end_row_idx > #self.vertical_string_list then end_row_idx = #self.vertical_string_list end
local row_count = end_row_idx == 0 and 1 or end_row_idx - start_row_idx + 1
-- We need a bb with the full height (even if we display only a few lines, we
-- may have to draw an image bigger than these lines)
local h = self.height or self.line_height_px * row_count
if self._bb then self._bb:free() end
local bbtype = nil
if self.line_num_to_image and self.line_num_to_image[start_row_idx] then
-- Whether Screen:isColorEnabled() or not, it's best to always use BBRGB32
-- and alphablitFrom() for the best display of various images:
-- With greyscale screen TYPE_BB8 (the default, and what we would
-- have chosen when not Screen:isColorEnabled()):
-- alphablitFrom: some images are all white (ex: flags on Milan, Ilkhanides on wiki.fr)
-- blitFrom: some images have a black background (ex: RDA, Allemagne on wiki.fr)
-- With TYPE_BBRGB32:
-- blitFrom: some images have a black background (ex: RDA, Allemagne on wiki.fr)
-- alphablitFrom: all these images looks good, with a white background
bbtype = Blitbuffer.TYPE_BBRGB32
end
self._bb = Blitbuffer.new(self.width, h, bbtype)
self._bb:fill(Blitbuffer.COLOR_WHITE)
local y = font_height
for i = start_row_idx, end_row_idx do
local line = self.vertical_string_list[i]
local pen_x = 0 -- when alignment == "left"
if self.alignment == "center" then
pen_x = (self.width - line.width)/2 or 0
elseif self.alignment == "right" then
pen_x = (self.width - line.width)
end
--@todo don't use kerning for monospaced fonts. (houqp)
-- refert to cb25029dddc42693cc7aaefbe47e9bd3b7e1a750 in master tree
RenderText:renderUtf8Text(self._bb, pen_x, y, self.face, line.text, true, self.bold, self.fgcolor, nil, line.char_pads)
y = y + self.line_height_px
end
-- Render image if any
self:_renderImage(start_row_idx)
end
function TextBoxWidget:_renderImage(start_row_idx)
local scheduled_update = self.scheduled_update
self.scheduled_update = nil -- reset it, so we don't have to whenever we return below
if not self.line_num_to_image or not self.line_num_to_image[start_row_idx] then
return -- no image on this page
end
local image = self.line_num_to_image[start_row_idx]
local do_schedule_update = false
local display_bb = false
local display_alt = false
local status_text = nil
local alt_text = image.title or ""
if image.caption then
alt_text = alt_text.."\n"..image.caption
end
-- Decide what to do/display
if image.bb then -- we have a bb
if scheduled_update then -- we're called from a scheduled update
display_bb = true -- display the bb we got
else
-- not from a scheduled update, but update from Tap on image
-- or we are back to this page from another one
if self.image_show_alt_text then
display_alt = true -- display alt_text
else
display_bb = true -- display the bb we have
end
end
else -- no bb yet
display_alt = true -- nothing else to display but alt_text
if scheduled_update then -- we just failed loading a bb in a scheduled update
status_text = "" -- show a warning triangle below alt_text
else
-- initial display of page (or back on it and previous
-- load_bb_func failed: try it again)
if image.load_bb_func then -- we can load a bb
do_schedule_update = true -- load it and call us again
status_text = "" -- display loading recycle sign below alt_text
end
end
end
-- logger.dbg("display_bb:", display_bb, "display_alt", display_alt, "status_text:", status_text, "do_schedule_update:", do_schedule_update)
-- Do what's been decided
if display_bb then
self._bb:alphablitFrom(image.bb, self.width - image.width, 0)
end
local status_height = 0
if status_text then
local status_widget = TextWidget:new{
text = status_text,
face = Font:getFace("cfont", 20),
fgcolor = Blitbuffer.COLOR_GREY,
bold = true,
}
status_height = status_widget:getSize().h
status_widget = FrameContainer:new{
background = Blitbuffer.COLOR_WHITE,
bordersize = 0,
margin = 0,
padding = 0,
RightContainer:new{
dimen = {
w = image.width,
h = status_height,
},
status_widget,
},
}
status_widget:paintTo(self._bb, self.width - image.width, image.height - status_height)
status_widget:free()
end
if display_alt then
local alt_widget = TextBoxWidget:new{
text = alt_text,
face = self.image_alt_face,
fgcolor = self.image_alt_fgcolor,
width = image.width,
-- don't draw over status_text if any
height = math.max(0, image.height - status_height),
}
alt_widget:paintTo(self._bb, self.width - image.width, 0)
alt_widget:free()
end
if do_schedule_update then
if self.image_update_action then
-- Cancel any previous one, if we changed page quickly
UIManager:unschedule(self.image_update_action)
end
-- Remember on which page we were launched, so we can
-- abort if page has changed
local scheduled_for_linenum = start_row_idx
self.image_update_action = function()
self.image_update_action = nil
if scheduled_for_linenum ~= self.virtual_line_num then
return -- no more on this page
end
local dismissed = image.load_bb_func() -- will update self.bb (or not if failure)
if dismissed then
-- If dismissed, the dismiss event may be resent, we
-- may soon just go display another page. So delay this update a
-- bit to see if that happened
UIManager:scheduleIn(0.1, function()
if scheduled_for_linenum == self.virtual_line_num then
-- we are still on the same page
self:update(true)
UIManager:setDirty("all", function()
-- return "ui", self.dimen
-- We can refresh only the image area, even if we have just
-- re-rendered the whole textbox as the text has been
-- rendered just the same as it was
return "ui", Geom:new{
x = self.dimen.x + self.width - image.width,
y = self.dimen.y,
w = image.width,
h = image.height,
}
end)
end
end)
else
-- Image loaded (or not if failure): call us again
-- with scheduled_update = true so we can draw what we got
self:update(true)
UIManager:setDirty("all", function()
-- return "ui", self.dimen
-- We can refresh only the image area, even if we have just
-- re-rendered the whole textbox as the text has been
-- rendered just the same as it was
return "ui", Geom:new{
x = self.dimen.x + self.width - image.width,
y = self.dimen.y,
w = image.width,
h = image.height,
}
end)
end
end
-- Wrap it with Trapper, as load_bb_func may be using some of its
-- dismissable methods
local Trapper = require("ui/trapper")
UIManager:scheduleIn(0.1, function() Trapper:wrap(self.image_update_action) end)
end
end
-- Return the position of the cursor corresponding to `self.charpos`,
-- Be aware of virtual line number of the scorllTextWidget.
function TextBoxWidget:_findCharPos()
if self.text == nil or string.len(self.text) == 0 then
return 0, 0
end
-- Find the line number.
local ln = self.height == nil and 1 or self.virtual_line_num
while ln + 1 <= #self.vertical_string_list do
if self.vertical_string_list[ln + 1].offset > self.charpos then
break
else
ln = ln + 1
end
end
-- Find the offset at the current line.
local x = 0
local offset = self.vertical_string_list[ln].offset
while offset < self.charpos do
x = x + self.char_width_list[offset].width + self.char_width_list[offset].pad
offset = offset + 1
end
return x + 1, (ln - 1) * self.line_height_px -- offset `x` by 1 to avoid overlap
end
function TextBoxWidget:moveCursorToCharpos(charpos)
self.charpos = charpos
local x, y = self:_findCharPos()
self.cursor_line:paintTo(self._bb, x, y)
end
-- Click event: Move the cursor to a new location with (x, y), in pixels.
-- Be aware of virtual line number of the scorllTextWidget.
function TextBoxWidget:moveCursor(x, y)
if x < 0 or y < 0 then return end
if #self.vertical_string_list == 0 then
-- if there's no text at all, nothing to do
return 1
end
local w = 0
local ln = self.height == nil and 1 or self.virtual_line_num
ln = ln + math.ceil(y / self.line_height_px) - 1
if ln > #self.vertical_string_list then
ln = #self.vertical_string_list
x = self.width
end
local offset = self.vertical_string_list[ln].offset
local idx = ln == #self.vertical_string_list and #self.char_width_list or self.vertical_string_list[ln + 1].offset - 1
while offset <= idx do
w = w + self.char_width_list[offset].width + self.char_width_list[offset].pad
if w > x then break else offset = offset + 1 end
end
if w > x then
local w_prev = w - self.char_width_list[offset].width - self.char_width_list[offset].pad
if x - w_prev < w - x then -- the previous one is more closer
w = w_prev
else
offset = offset + 1
end
end
self:free()
self:_renderText(1, #self.vertical_string_list)
self.cursor_line:paintTo(self._bb, w + 1,
(ln - self.virtual_line_num) * self.line_height_px)
return offset
end
function TextBoxWidget:getVisLineCount()
return math.floor(self.height / self.line_height_px)
end
function TextBoxWidget:getAllLineCount()
return #self.vertical_string_list
end
function TextBoxWidget:update(scheduled_update)
self:free()
-- We set this flag so :_renderText() can know we were called from a
-- scheduled update and so not schedule another one
self.scheduled_update = scheduled_update
self:_renderText(self.virtual_line_num, self.virtual_line_num + self:getVisLineCount() - 1)
self.scheduled_update = nil
end
function TextBoxWidget:onTapImage(arg, ges)
if self.line_num_to_image and self.line_num_to_image[self.virtual_line_num] then
local image = self.line_num_to_image[self.virtual_line_num]
local tap_x = ges.pos.x - self.dimen.x
local tap_y = ges.pos.y - self.dimen.y
-- Check that this tap is on this image
if tap_x > self.width - image.width and tap_x < self.width and
tap_y > 0 and tap_y < image.height then
logger.dbg("tap on image")
if image.bb then
-- Toggle between image and alt_text
self.image_show_alt_text = not self.image_show_alt_text
self:update()
UIManager:setDirty("all", function()
-- return "ui", self.dimen
-- We can refresh only the image area, even if we have just
-- re-rendered the whole textbox as the text has been
-- rendered just the same as it was
return "ui", Geom:new{
x = self.dimen.x + self.width - image.width,
y = self.dimen.y,
w = image.width,
h = image.height,
}
end)
return true
end
end
end
end
-- TODO: modify `charpos` so that it can render the cursor
function TextBoxWidget:scrollDown()
self.image_show_alt_text = nil -- reset image bb/alt state
local visible_line_count = self:getVisLineCount()
if self.virtual_line_num + visible_line_count <= #self.vertical_string_list then
self:free()
self.virtual_line_num = self.virtual_line_num + visible_line_count
self:_renderText(self.virtual_line_num, self.virtual_line_num + visible_line_count - 1)
end
return (self.virtual_line_num - 1) / #self.vertical_string_list, (self.virtual_line_num - 1 + visible_line_count) / #self.vertical_string_list
end
-- TODO: modify `charpos` so that it can render the cursor
function TextBoxWidget:scrollUp()
self.image_show_alt_text = nil
local visible_line_count = self:getVisLineCount()
if self.virtual_line_num > 1 then
self:free()
if self.virtual_line_num <= visible_line_count then
self.virtual_line_num = 1
else
self.virtual_line_num = self.virtual_line_num - visible_line_count
end
self:_renderText(self.virtual_line_num, self.virtual_line_num + visible_line_count - 1)
end
return (self.virtual_line_num - 1) / #self.vertical_string_list, (self.virtual_line_num - 1 + visible_line_count) / #self.vertical_string_list
end
function TextBoxWidget:scrollToRatio(ratio)
self.image_show_alt_text = nil
ratio = math.max(0, math.min(1, ratio)) -- ensure ratio is between 0 and 1 (100%)
local visible_line_count = self:getVisLineCount()
local page_count = 1 + math.floor((#self.vertical_string_list - 1) / visible_line_count)
local page_num = 1 + Math.round((page_count - 1) * ratio)
local line_num = 1 + (page_num - 1) * visible_line_count
if line_num ~= self.virtual_line_num then
self:free()
self.virtual_line_num = line_num
self:_renderText(self.virtual_line_num, self.virtual_line_num + visible_line_count - 1)
end
return (self.virtual_line_num - 1) / #self.vertical_string_list, (self.virtual_line_num - 1 + visible_line_count) / #self.vertical_string_list
end
function TextBoxWidget:getSize()
if self.width and self.height then
return Geom:new{ w = self.width, h = self.height}
else
return Geom:new{ w = self.width, h = self._bb:getHeight()}
end
end
function TextBoxWidget:moveCursorUp()
if self.vertical_string_list and #self.vertical_string_list < 2 then return end
local x, y
x, y = self:_findCharPos()
local charpos = self:moveCursor(x, y - self.line_height_px +1)
if charpos then
self:moveCursorToCharpos(charpos)
end
end
function TextBoxWidget:moveCursorDown()
if self.vertical_string_list and #self.vertical_string_list < 2 then return end
local x, y
x, y = self:_findCharPos()
local charpos = self:moveCursor(x, y + self.line_height_px +1)
if charpos then
self:moveCursorToCharpos(charpos)
end
end
function TextBoxWidget:paintTo(bb, x, y)
self.dimen.x, self.dimen.y = x, y
bb:blitFrom(self._bb, x, y, 0, 0, self.width, self._bb:getHeight())
end
function TextBoxWidget:free()
logger.dbg("TextBoxWidget:free called")
-- :free() is called when our parent widget is closing, and
-- here whenever :_renderText() is being called, to display
-- a new page: cancel any scheduled image update, as it
-- is no more related to current page
if self.image_update_action then
logger.dbg("TextBoxWidget:free: cancelling self.image_update_action")
UIManager:unschedule(self.image_update_action)
end
if self._bb then
self._bb:free()
self._bb = nil
end
end
-- Allow selection of a single word at hold position
function TextBoxWidget:onHoldWord(callback, ges)
if not callback then return end
local x, y = ges.pos.x - self.dimen.x, ges.pos.y - self.dimen.y
local line_num = math.ceil(y / self.line_height_px) + self.virtual_line_num-1
local line = self.vertical_string_list[line_num]
logger.dbg("holding on line", line)
if line then
local char_start = line.offset
local char_end -- char_end is non-inclusive
if line_num >= #self.vertical_string_list then
char_end = #self.char_width_list + 1
else
char_end = self.vertical_string_list[line_num+1].offset
end
local char_probe_x = 0
local idx = char_start
-- find which character the touch is holding
while idx < char_end do
local c = self.char_width_list[idx]
-- FIXME: this might break if kerning is enabled
char_probe_x = char_probe_x + c.width + c.pad
if char_probe_x > x then
-- ignore spaces
if c.char == " " then break end
-- now find which word the character is in
local words = util.splitToWords(line.text)
local probe_idx = char_start
for _, w in ipairs(words) do
-- +1 for word separtor
probe_idx = probe_idx + #util.splitToChars(w)
if idx <= probe_idx - 1 then
callback(w)
return
end
end
break
end
idx = idx + 1
end
end
return
end
-- Allow selection of one or more words (with no visual feedback)
-- Gestures should be declared in widget using us (e.g dictquicklookup.lua)
-- Constants for which side of a word to find
local FIND_START = 1
local FIND_END = 2
function TextBoxWidget:onHoldStartText(_, ges)
-- just store hold start position and timestamp, will be used on release
self.hold_start_x = ges.pos.x - self.dimen.x
self.hold_start_y = ges.pos.y - self.dimen.y
self.hold_start_tv = TimeVal.now()
return true
end
function TextBoxWidget:onHoldReleaseText(callback, ges)
if not callback then return end
local hold_end_x = ges.pos.x - self.dimen.x
local hold_end_y = ges.pos.y - self.dimen.y
-- check we have seen a HoldStart event
if not self.hold_start_tv then
return false
end
-- check start and end coordinates are actually inside our area
if self.hold_start_x < 0 or hold_end_x < 0 or
self.hold_start_x > self.dimen.w or hold_end_x > self.dimen.w or
self.hold_start_y < 0 or hold_end_y < 0 or
self.hold_start_y > self.dimen.h or hold_end_y > self.dimen.h then
return false
end
local hold_duration = TimeVal.now() - self.hold_start_tv
hold_duration = hold_duration.sec + hold_duration.usec/1000000
-- If page contains an image, check if Hold is on this image and deal
-- with it directly
if self.line_num_to_image and self.line_num_to_image[self.virtual_line_num] then
local image = self.line_num_to_image[self.virtual_line_num]
if hold_end_x > self.width - image.width and hold_end_y < image.height then
-- Only if low-res image is loaded, so we have something to display
-- if high-res loading is not implemented or if its loading fails
if image.bb then
logger.dbg("hold on image")
local load_and_show_image = function()
if not image.hi_bb and image.load_bb_func then
image.load_bb_func(true) -- load high res image if implemented
end
-- display hi_bb, or low-res bb if hi_bb has not been
-- made (if not implemented, or failed, or dismissed)
local ImageViewer = require("ui/widget/imageviewer")
local imgviewer = ImageViewer:new{
image = image.hi_bb or image.bb, -- fallback to low-res if high-res failed
image_disposable = false, -- we may re-use our bb if called again
with_title_bar = true,
title_text = image.title,
caption = image.caption,
fullscreen = true,
}
UIManager:show(imgviewer)
end
-- Wrap it with Trapper, as load_bb_func may be using some of its
-- dismissable methods
local Trapper = require("ui/trapper")
UIManager:scheduleIn(0.1, function() Trapper:wrap(load_and_show_image) end)
-- And we return without calling the "Hold on text" callback
return true
end
end
end
-- Swap start and end if needed
local x0, y0, x1, y1
-- first, sort by y/line_num
local start_line_num = math.ceil(self.hold_start_y / self.line_height_px)
local end_line_num = math.ceil(hold_end_y / self.line_height_px)
if start_line_num < end_line_num then
x0, y0 = self.hold_start_x, self.hold_start_y
x1, y1 = hold_end_x, hold_end_y
elseif start_line_num > end_line_num then
x0, y0 = hold_end_x, hold_end_y
x1, y1 = self.hold_start_x, self.hold_start_y
else -- same line_num : sort by x
if self.hold_start_x <= hold_end_x then
x0, y0 = self.hold_start_x, self.hold_start_y
x1, y1 = hold_end_x, hold_end_y
else
x0, y0 = hold_end_x, hold_end_y
x1, y1 = self.hold_start_x, self.hold_start_y
end
end
-- Reset start infos, so we do not reuse them and can catch
-- a missed start event
self.hold_start_x = nil
self.hold_start_y = nil
self.hold_start_tv = nil
-- similar code to find start or end is in _findWordEdge() helper
local sel_start_idx = self:_findWordEdge(x0, y0, FIND_START)
local sel_end_idx = self:_findWordEdge(x1, y1, FIND_END)
if not sel_start_idx or not sel_end_idx then
-- one or both hold points were out of text
return true
end
local selected_text = table.concat(self.charlist, "", sel_start_idx, sel_end_idx)
logger.dbg("onHoldReleaseText (duration:", hold_duration, ") :", sel_start_idx, ">", sel_end_idx, "=", selected_text)
callback(selected_text, hold_duration)
return true
end
function TextBoxWidget:_findWordEdge(x, y, side)
if side ~= FIND_START and side ~= FIND_END then
return
end
local line_num = math.ceil(y / self.line_height_px) + self.virtual_line_num-1
local line = self.vertical_string_list[line_num]
if not line then
return -- below last line : no selection
end
local char_start = line.offset
local char_end -- char_end is non-inclusive
if line_num >= #self.vertical_string_list then
char_end = #self.char_width_list + 1
else
char_end = self.vertical_string_list[line_num+1].offset
end
local char_probe_x = 0
local idx = char_start
local edge_idx = nil
-- find which character the touch is holding
while idx < char_end do
local c = self.char_width_list[idx]
char_probe_x = char_probe_x + c.width + c.pad
if char_probe_x > x then
-- character found, find which word the character is in, and
-- get its start/end idx
local words = util.splitToWords(line.text)
-- words may contain separators (space, punctuation) : we don't
-- discriminate here, it's the caller job to clean what was
-- selected
local probe_idx = char_start
local next_probe_idx
for _, w in ipairs(words) do
next_probe_idx = probe_idx + #util.splitToChars(w)
if idx < next_probe_idx then
if side == FIND_START then
edge_idx = probe_idx
elseif side == FIND_END then
edge_idx = next_probe_idx - 1
end
break
end
probe_idx = next_probe_idx
end
if edge_idx then
break
end
end
idx = idx + 1
end
return edge_idx
end
return TextBoxWidget