Read XLSX - Android Software Development

Is there a library that can read XLSX file and works on android?
I was trying with POI library, but apparently poi-ooxml-schemas-3.8 library is too bulky and I will get "No expanded opcode" error, which, as I understand means that project exceeds dalvik's method limit.

Related

CRC calculation

I have been trying to get a better understanding of CRC calculations. There is a lot of table based code that can be used available freely on the net but I want to implement my own basic technique first to get a fuller understanding. I have made a class to do the calculations and manually calculated an example to verify the code and they both agree. The problem is that based on this http://www.createwindow.com/programming/crc32/crcverify.htm my answer is wrong. If anyone could look over the attached txt file I would be great full. I can't post it here because the formatting would be lost and it would be impossible to read (very long division). The text I crc is resume (only those chars). The polynomial I use is the standard one used in zip 0x04C11DB7 when computing or 0x104C11DB7 when doing manually (the msb always cancels out).
It could just be that a table driven implementation generates a different crc, but I doubt it.
(log on to see attachment)

MortScript Manual - CHM Format

Reading the PDF version of MortScript manual is a pain in my phone. I really like the HTML manual for MortScript. But, it's bit slow, single big file, the formatting is not really up to the standard of a good technical manual, and lack of search functionality.
On the other hand, I really enjoy reading the CHM on the phone or on the PC, the CHM format provides more ways to access the information, better search, possible indexes for the contents and good navigation. So I have just created one, with a nice table of content for CHM.
I have started a bit of reformatting work, especially on the chapter 9. But not yet completed, and it's a long way to go. But I think, it's better to share it earlier. I would like to add the indexes as well in future. I will post the updates if there is any.
Credit goes to Donny Bahama for the HTML version (as described above).

Microsoft (MS) eReader Issues and a Fix

Not much has been said about the Microsoft (MS) ereader app on this forum (that I could find), but I found an extensive discussion on a Microsoft forum (http://social.answers.microsoft.com...e/thread/49DD09A8-3B32-4F97-AAA3-2585818F03DF). The problem is that MS Reader does not work well with WM6.5. Several people, including me, have been told by MS support staff that MS Reader does not work with WM6.5. That is not quite correct. There are activation issues (see below), but the main problem is that DRM/locked (copyrighted) books cannot be opened on WM6.5 systems such as the HTC HD2. Trying to do so will cause the program to hang and a soft reset is necessary. I was able to open and read unlocked, public domain books in the LIT format.
The current version of MS Reader for smartphones is 3.4.2. (See http://www.microsoft.com/reader/downloads/ppc.aspx) It was intended for WM6.0 and WM6.1. Changes in WM6.5 apparently conflict with the reading of DRM books.
A number of HD2 users experienced problems activating MS Reader. Apparently, a file - OEMInfo.xml - was missing. This file is required for the activation process. The missing file may be due to replacing the stock ROM. My HD2 with stock ROM 2.13.531.1 has the file, and I was able to install and activate the MS Reader. If the file is not available from HTC, the link above has references on how to obtain the file. (I tried contacting the person referred to, but never heard from her.) If you want to use MS Reader to read your old LIT files, first make sure you have the OEMInfo.xml file in the Windows folder, or try to obtain a copy.
There are some programs that can convert LIT files to other formats that other ereader apps support, but these converters will not convert DRM/locked files. My solution was to use the ConvertLit program's "down convert" feature. I used the GUI version of the program because it was "easier" to use (see http://dukelupus.pri.ee/convertlit.php). With this program on my PC, I was able to unlock or decrypt the DRM books I had purchased over the years. I consider this "fair use" since it for my personal use and I don't make the files available to anyone else.
You will need to have the desktop version of MS Reader installed and activated on your PC (http://www.microsoft.com/reader/downloads/pc.aspx). I am able to read my DRM books with the desktop version on my Vista PC. (Please read and follow the directions on the MS Reader website for using PCs with Vista to activate MS Reader on the PC or smartphone. It requires running your browser in Administrator mode. Windows 7 PCs have a different set of problems. I can't even get a Win7 PC to recognize my HD2, but that is another issue.)
Next, install the ConvertLit GUI program and start it. Also start the desktop MS Reader program. Select a LIT file in ConvertLit, in the My Library folder under My Documents by default. Select your output folder or check the box to use the input folder. The converted file will be renamed so you don't lose your original file. Click on the Downconvert button at the top. The first time you do this, you will be prompted that the keys.txt file is missing. Also, you may be asked to select a DRM book in MS Reader. Open the MS Reader library and select any DRM/locked book. You are asked if you want to use the Key Convert program. Click Yes to any prompts. After a short time, you should get a message that the keys.txt file has been created. Close the dialog for the key conversion program.
You may still get an error message that the keys.txt file is missing when you again click the Downconvert button. I believe the keys.txt file got created in the My Library folder. You may need to copy this file to the ConvertLit folder under Program Files on your PC. The error message indicates where the file is needed. Once I did that, I was able to select a LIT file, click the Downconvert button, and get a decrypted file, slightly smaller than the original file. I copied the file to my HD2 using my PC's File Explorer. (I also removed the locked copy already on my HD2 that would not work.) I was able to open and read the file with no problem. I was even able to convert multiple books at one time.
The advantage to this process is that is does not require converting the file to another format, although ConvertLit can do that after unlocking the file.
One issue with the MS Reader is page turning. The program was designed for hardware buttons or the D-ring to change pages. These don't exist on most new smartphones. It is necessary to tap on the turn page links at the bottom of the screen. This takes some practice and occasionally multiple taps.
With both Amazon and Barnes & Noble providing ebook readers for various other OS's, I would not be surprised to see them on the new WindowsPhone 7 phones in the near future.. But I will be surprised if we see an upgrade of the MS Reader for LIT files. Taking your LIT files to a WinPhone7 system probably will require converting files to another format that has a WM7 supported ereader program.
I bought an DRM'd book a while back and it was in M$ Reader format. I've gotten it to work on my desktop but never have on my Hd2 (or before that on my Toshiba). I do have my HD2 activated (what a pain) but it's worthless in my opinion.
mknewman said:
I bought an DRM'd book a while back and it was in M$ Reader format. I've gotten it to work on my desktop but never have on my Hd2 (or before that on my Toshiba). I do have my HD2 activated (what a pain) but it's worthless in my opinion.
Click to expand...
Click to collapse
The method I describe above may not be worth the time and effort for one or two locked MS reader LIT books, but if you have a number of them as I did, it is very useful. I now have my DRM books unlocked and readable on my HD2.

[LIB] NiceQL - makes database access easier

Let me introduce you my small library called NiceQL. It is free, open source and BSD-licenced.
It's main purpose is to make the process of creating databases easier. Hard-coding inside SQLiteOpenHelper is a no-go in my opinion. NiceQL gives developers a set of tools to create and manage database scheme, its tables, their columns and indices and preload seed data (data to be populated at first app launch). Library allows to generate database on a fly, load it from XML, use built-in SQL generators or use plain SQL (from XML too), you may also extend its objects or write new ones implementing Java interfaces.
Here's a quick code to start-up database with NiceQL and scheme in XML resource:
Code:
SQLiteDatabase db = new SchemeOpenHelper(this, "my_database", XmlScheme.parse(this, R.xml.sql_scheme)).getWritableDatabase();
The library is fully documented with examples on GitHub wiki. It does not handle database upgrades just yet, but this functionality will be implemented very soon.
I hope you will find it useful.

C++: open file for writing in the LocalStorage

Hi guys, could you tell me how to open file for writing in the phone app LocalStorage for the non-unlocked handset (regular app for store)?
Code below doesn't work
Code:
FILE *tmp;
auto tmpPath = Windows::Storage::ApplicationData::Current->LocalFolder->Path + "\\tmp.txt";
auto tmpErr = _wfopen_s(&tmp, tmpPath->Data(), L"w");
Any suggestions?
Try looking though msdn articles. I found it somewhere in there. But I have forgotten it now.
Sent from Board Express on my Nokia Lumia 1020. Best phone ever!!
Note to noobs: DON'T PM ME WITH QUESTIONS. POST IN THE FORUMS. THAT'S WHAT THEY ARE HERE FOR!
@wcomhelp, please keep your rtfm advices for yourself, OK? I'm not a noob and of course I've searched msdn, google, codeplex, github etc. and so on before posting here. If you don't know how, much better be silent (like others who read this post but have no idea what I'm talking about)
I've tried a few possible methods including ugly "MS-way" with task & lambda syntax (see below) but nothing worked as it should be (code below works if no file exist and fails if file already exist - CreationCollisionOption::ReplaceExisting options is not worked/not implemented/buggy/billgates_knows_only ).
Code:
auto folder = Windows::Storage::ApplicationData::Current->LocalFolder;
Concurrency::task<Windows::Storage::StorageFile^> createFileOp(
folder->CreateFileAsync(CONFIG_FILE_NAME, Windows::Storage::CreationCollisionOption::ReplaceExisting));
createFileOp.then([=](Windows::Storage::StorageFile^ file)
{
return file->OpenAsync(Windows::Storage::FileAccessMode::ReadWrite);
})
.then([=](Windows::Storage::Streams::IRandomAccessStream^ stream)
{
auto outputStream = stream->GetOutputStreamAt(0);
auto dataWriter = ref new Windows::Storage::Streams::DataWriter(outputStream);
// data save code skipped
return dataWriter->StoreAsync();
})
.wait();
BTW, I've used workaround, to save ported C++ app data to the LocalSettings instead of text file (as it was in original code).
"Doesn't work" doesn't give us a lot to go on, troubleshooting-wise. Can you tell us what error you get?
Only thing I see in the code that looks a little weird is that the
Code:
"\\tmp.txt"
part isn't explicitly a wide-character string, but I'd expect string concatenation to take care of that.
Also, out of curiosity, why libc functions instead of Win32? Obviously, the code you're writing here isn't intended for much portability...
@GoodDayToDie, there is no error code at all - standard POSIX functions returns NULL FILE, the ::GetLastError() also return 0.
I'm porting old C-style app to WinRT platform and don't care about portability (but the first post code - just a simplified example, nothing more).
POSIX (libc) functions works pretty well for reading only but not for writing - that's the problem...
As I said before, I resolved my issue by workaround but still curious why the POSIX calls fails for file writing in the app storage.
buuuuuuuuuuuuuuuuh
No need for lambdas
https://paoloseverini.wordpress.com/2014/04/22/async-await-in-c/
You may also want to rethink your strategy
You can't create files at arbitrary locations, so your method is kinda redundant. All the locations you are allowed to create and read files to/from are available through KnowFolders and ApplicationData classes. These return StorageFolders which in turn can create files with CreateFileAsync (used for both creating and opening existing files) and get files with GetFilesAsync ( I recommend against this one though) and similar methods.
@mcosmin222, could you please re-read my posts one more time? I'm not trying to create files at "arbitrary locations"; I wanna create/write simple text file at the app's local storage (which one should be available for reading/writing). And the problem not in the lambdas or task usage (yes, it looks ugly but it works as it supposed to be).
Could you provide a working example instead of words? And I'll be glad to say you "thanks a lot"; can't say now...
sensboston said:
@mcosmin222, could you please re-read my posts one more time? I'm not trying to create files at "arbitrary locations"; I wanna create/write simple text file at the app's local storage (which one should be available for reading/writing). And the main problem not in the task (async execution).
Could you provide a working example instead of words? And I'll be glad to say you "thanks a lot"; can't say now...
Click to expand...
Click to collapse
Sure, just gimmie a few hours till I can get near a compiler that is capable of doing that
Of course, no rush at all, take your time. It's not a showstopper for me now (actually, my workaround with AppSettings is more preferable way - at least for universal app and roaming settings) but the issue still has an "academic interest" and maybe will be useful in the next projects for porting old C/C++ code to WinRT.
sensboston said:
Of course, no rush at all, take your time. It's not a showstopper for me now (actually, my workaround with AppSettings is more preferable way - at least for universal app and roaming settings) but the issue still has an "academic interest" and maybe will be useful in the next projects for porting old C/C++ code to WinRT.
Click to expand...
Click to collapse
hi
in vs 2015
#include <pplawait.h>
Something of the like should work
Code:
WriteSomeFile() __resumable
{
auto local = ApplicationData::Current->LocalFolder;
auto file = __await local->CreateFileAsync("some file", CreationCollisionOption::eek:penIfExists);
__await FileIO::WriteTextAsync(file, "this is some text");
}
However, as of right now, in VS 2015 RC, you have a host of limitations when dealing with this, but I do not believe this will be of any issue to you.
Code:
Cannot use Windows Runtime (WinRT) types in the signature of resumable function and resumable function cannot be a member function in a WinRT class. (This is fixed, but didn't make it in time for RC release)
We may give a wrong diagnostic if return statement appears in resumable function prior to seeing an await expression or yield statement. (Workaround: restructure your code so that the first return happens after yield or await)
Compiling code with resumable functions may result in compilation errors or bad codegen if compiled with /ZI flag (Edit and Continue debugging)
Parameters of a resumable function may not be visible while debugging
Please see this link for additional details
http://blogs.msdn.com/b/vcblog/archive/2015/04/29/more-about-resumable-functions-in-c.aspx
you should also note that this works with native, standard C++ types.
@mcosmin222, looks like unbuffered writing works (i.e. without streams) fine but it still not an answer for my initial question
I'm curious why the standard POSIX libc writing operations are not working on the app's local storage (but reading from files works fine). Actually, it's all about porting old C/C++ code for WinRT; of course for the new app it's not a problem but re-writing old code to FileIO should be a huge pain in the ass. What I did: I've "mechanically" changed all libc formatted outputs from file to string, and use LocalSettings class (actually it's XML file) to store that string (I'm planning also change LocalSettings to RoamingSettings, to provide settings consistency between WP & desktop app).
P.S. <pplawait.h> is not available in my VS 2015 (release pro version) so I've tested by using lambda pattern.
OK, first things first, LIBC != POSIX! The POSIX way to do this would be to call the open() function and get back an int as an "fd" (file descriptor), which is of course not implemented on Windows Phone because Windows Phone is not a POSIX platform (you might find the Windows compatibility functions _open() and _wopen(), but I doubt it). You are attempting to use the standard C library functions, which are portable but implement kind of a lowest common denominator of functionality and are generally slightly slower than native APIs because they go through a portability wrapper.
Second, sorry to be all RTFM on you but you should really Read The Manual (or manpage, or, since this is Windows, the MSDN page)! Libc APIs set errno (include errno.h) and use different error values than Windows system error codes (or HRESULT codes, or NTSTATUS codes, or...). Error reporting in C is a mess. If you were calling CreateFile(), you would check GetLastError(), but since you're calling _wfopen(), you check errno (not a function).
@GoodDayToDie, _wfopen_s returns 0 (i.e. "no error") but tmp pointer receives also 0 (NULL) Could you explain why libc file functions are working for reading (at the app installation & local data folders of course) but not for writing? Any logical ("msdn based") explanation? Or you just... don't know, heh?
sensboston said:
@GoodDayToDie, _wfopen_s returns 0 (i.e. "no error") but tmp pointer receives also 0 (NULL) Could you explain why libc file functions are working for reading (at the app installation & local data folders of course) but not for writing? Any logical ("msdn based") explanation? Or you just... don't know, heh?
Click to expand...
Click to collapse
LIBC functions will most likely work just in debug mode. The moment you try to publish the app it will fail. You can do lots of crazy stuff on your developer device with basic C functions, but if you try publishing, it won't pass the marketplace verification.
Most C APIs are simply not supported, since they do not comply with the sandbox environment of the Windows Runtime.
The code I gave you is tested with VS 2015 RC. You should be able to include <pplawait.h> just fine, if you are targeting toolchains newer than November 2013.
mcosmin222 said:
The moment you try to publish the app it will fail. You can do lots of crazy stuff on your developer device with basic C functions, but if you try publishing, it won't pass the marketplace verification.
Click to expand...
Click to collapse
Hmm... Are you sure or it's just your assumption? My app is still under development but (just for test!) I've made store app package for WP and it passed local store verification I also uploaded package to the store (via browser) and it also passed. I don't have time to create all tiles and fill all fields to complete beta-submission (actually, I don't know how to mark app as beta in the new dashboard) but for me it looks like app don't have any problem and will pass store certification easily. And you may be sure - it uses A LOT of libc calls 'cause originally it was written for Linux (or kind of UX system)
sensboston said:
Hmm... Are you sure or it's just your assumption? My app is still under development but (just for test!) I've made store app package for WP and it passed local store verification I also uploaded package to the store (via browser) and it also passed. I don't have time to create all tiles and fill all fields to complete beta-submission (actually, I don't know how to mark app as beta in the new dashboard) but for me it looks like app don't have any problem and will pass store certification easily. And you may be sure - it uses A LOT of libc calls 'cause originally it was written for Linux (or kind of UX system)
Click to expand...
Click to collapse
Once usage reports get up to microsoft, you will be given a notice to fix the offending API (happened to be once). You are much better off using the platform specific tools: not only they are much faster, they are also much safer and you won't have problems later on.
You might get away with reading stuff (since reading is not that harmful), but you should be using the winRT APIs each time they are available.
Simply uploading your app to the marketplace just reruns the local tests in their cloud servers: once you submit the actual app (not beta, not tests) for consumers, it will be much more aggressively checked. This is because the store allows specific scenarios for distributing apps in close circles that may break the usual validation rules.
@mcosmin222, one more time: is it your assumptions or personal experience? I don't know how many apps you have in store (I do have a lot) but I never heard that you said. I've used C++ libraries with WP hacks in some of published apps but never had any problem with "aggressive checks". What I know: if you are using some "prohibited" calls, your app will not pass uploading to the store (uploading, not a certification).
P.S. I'll send you personally a link when I publish release Hope, you'll like it
sensboston said:
@mcosmin222, one more time: is it your assumptions or personal experience? I don't know how many apps you have in store (I do have a lot) but I never heard that you said. I've used C++ libraries with WP hacks in some of published apps but never had any problem with "aggressive checks". What I know: if you are using some "prohibited" calls, your app will not pass uploading to the store (uploading, not a certification).
P.S. I'll send you personally a link when I publish release Hope, you'll like it
Click to expand...
Click to collapse
By "hacking" you mean recompiling the code to fit the windows phone toolchain? if so, then you shouldn't have to worry about too many things.
but even so, calling stuff like fopen in locations other than local storage will get your app banned. Even if it makes past the first publication, you can get noticed weeks later or even months (yes, it did happen to me personally).
In most cases, calling C APIs that can potentially break the sandbox (like opening a file in doc library with fopen) will always fail the marketplace verification, eventually. If it hasn't happened to you yet, then you may have not been using such APIs.
No, my C++ code is not accessing other than approved locations but the app has a lot of libс (and of course other C/C++ libs) calls; I'm 99.9% sure it's legitimate and will be not a source of any problem. Otherwise what is the advantages of having C++ compiler?!
As far as I know, just some of API's are prohibited but you will notice it right after local store compatibility test run...
As for "hacks" I mean usage of undocumented ShellChromeAPI calls (including loading hack).
P.S. I've found why <pplawait.h> header is missing. Initially I've created solution with the 12.0 toolset but now I can't (or don't know how to) change it to 14. However creating the new empty universal solution in VS 2015 also gives me toolset 12 by default. What is the toolset 14 for? Windows 10?
sensboston said:
No, my C++ code is not accessing other than approved locations but the app has a lot of libс (and of course other C/C++ libs) calls; I'm 99.9% sure it's legitimate and will be not a source of any problem. Otherwise what is the advantages of having C++ compiler?!
As far as I know, just some of API's are prohibited but you will notice it right after local store compatibility test run...
As for "hacks" I mean usage of undocumented ShellChromeAPI calls (including loading hack).
P.S. I've found why <pplawait.h> header is missing. Initially I've created solution with the 12.0 toolset but now I can't (or don't know how to) change it to 14. However creating the new empty universal solution in VS 2015 also gives me toolset 12 by default. What is the toolset 14 for? Windows 10?
Click to expand...
Click to collapse
The advantage of C++ is the obvious versatility: the standard C++ APIs will work fine for you as long as you stay inside the sandbox (this means you can't access files even in locations that are outside of sandbox but you have permission to them, such as music library). You can use most classic C/C++ libraries without issues as long as you do the interface with the runtime broker yourself. That means using windows runtime APIs instead of classic C APIs when dealing with stuff such as file access, for example. This is a pretty extensive topic and It is rather difficult to explain it all with 100% accuracy, especially when there is lots of docs running around.
You also get deterministic memory management, which is huge in specific scenarios.
Long story short
You will be fine with standard C/C++ when using
any in-memory functions supported by the compiler (you can manipulate data types, string, mutex, etc).
File IO in isolated storage only (applicationData folder)
Threads (although you are better off using threadpool or the like, it is much easier and cleaner). You can also use futures, and std::this_thread.
You will have to use winRT replacement
File system access in any other location than application data (you must use the windows::storage APIs)
sockets, internet access and the like.
any hardware related thing: music&video playerback must be interfaced through winRT (although the underlying decoders can be classic C/C++), messing around with the device sensors.
Retrieving system properties (internet connection state etc)
cross process communications
communicating with other apps
There are also win32 equivalents
mutex, threading, fileIO (isolated storage only)
Media playback with custom rendering pipeline.
Basically, winRT functions as an abstraction layer between the hardware and your code. You can use classic C++ up to the point where you need to interact with the system in any way. At that point, system interaction must be done with winRT. This way, microsoft ensures a higher degree of stability and security for devices.
check this link out for more information on the toolchains. You should be able to use this in VS 2013 as well with windows 8 (this is a compiler feature, has nothing to do with supported platform)
https://paoloseverini.wordpress.com/2014/04/22/async-await-in-c/

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