FR: Open links in PocketBook web browser

[liskin]

Many PocketBook devices include a web browser, but when clicking a link in KOReader, there's no option to open the link in the browser, there's only an option to show a QR code (which can then be scanned by a smartphone). It would be useful if KOReader offered an option to open it directly on the device browser itself.

I was able to make this work on PB740 (InkPad 3) using the following userpatch (1-pocketbook-browser.lua):

local PocketBook = require("device/pocketbook/device")
local ffi = require("ffi")
local C = ffi.C
local inkview = ffi.load("inkview")

require("ffi/inkview_h")
ffi.cdef[[
/**
 * @brief OpenTask runs child process or make active existing process of specified exe if exist
 * @param path - path/to/exe
 * @param argc - args ptr
 * @param argv - args count
 * @param flags - TASK_* macros
 * @return 0 if created | 1 if already exist | -1 if fail
 */
int OpenTask(const char *path, int argc, const char * const* argv, int flags);
]]

function PocketBook:canOpenLink()
    return true
end

function PocketBook:openLink(link)
    if not link or type(link) ~= "string" then return end
    local argv = ffi.new("const char *[1]", {link})
    inkview.OpenTask("/usr/bin/browser.app", 1, argv, C.TASK_MAKEACTIVE)
end

I'm now seeking advice how to proceed if I wanted to submit this to KOReader as a PR. OpenTask is not available in the old SDK that's used for building KOReader for PocketBook, and I was unable to make this work using NewTask (it works once and then keeps segfaulting). So I can't just add OpenTask to base/ffi-cdecl/inkview_decl.c and use it.

Any ideas?

(I'll keep playing with NewTask and other inkview stuff a bit more but I'm not super hopeful.)

[liskin]

OpenTask itself seems to be implemented via NewTaskEx, but it also calls stuff like hw_task_findbyappname and sendParametersToTaskNoWait so I guess if I understood ARM assembly or used a decompiler I could theoretically piece a compat implementation of OpenTask together…

But then it's probably completely fine to just make this available on modern PocketBooks, if that's something that can be done.

[pazos]

But then it's probably completely fine to just make this available on modern PocketBooks, if that's something that can be done

That's totally ok. You can use PocketBook:getSoftwareVersion()

No real idea about the minimum supported version but I guess you could try from the major version your firmware is currently in and assume all devices work the same.

[liskin]

https://github.com/koreader/koreader/blob/master/frontend/device/pocketbook/device.lua#L400-L402

Well, that doesn't really solve anything. I can easily check for the existence of OpenTask this way:
https://github.com/koreader/koreader-base/blob/9a90ea881201ae64f188150b4e3c02daeb3901bc/ffi/input_pocketbook.lua#L17

But the issue is that it needs to be declared first, and I'm not meant to change base/ffi/inkview_h.lua manually, it's generated from base/ffi-cdecl/inkview_decl.c which uses the real inkview.h, but the one used is too old and doesn't have OpenTask.

I can obviously just ffi.cdef it manually but is that really something I'm meant to do?

[pazos]

Well, that doesn't really solve anything. I can easily check for the existence of OpenTask this way

cool :)

But the issue is that it needs to be declared first, and I'm not meant to change base/ffi/inkview_h.lua manually, it's generated from base/ffi-cdecl/inkview_decl.c which uses the real inkview.h, but the one used is too old and doesn't have OpenTask.

I can obviously just ffi.cdef it manually but is that really something I'm meant to do?

It is totally ok to define platform's behaviour manually. see android cdefs

Please keep base/ffi/inkview_h.lua as is and put your code somewhere else.

I'm not very fan of our current base/front split so maybe others can give you some suggestion.
I guess it belongs to base, I don't know if it worths the hussle to move it there.

[liskin]

Armed with https://ghidra-sre.org/, I've actually managed to make it work using NewTaskEx as well, so I might not need to declare OpenTask after all. I'll keep playing with it for a bit more as it's quite fun and then open a PR once I have something robust enough 🙂