How do I remove a library from the arduino environment? - arduino

In the Arduino GUI on windows, if I click on Sketch --> Import Library, at the bottom of the menu there is a section called "Contributed".
Unfortunately, I had misclicked and added a library I did not want to that list.
How can I remove it from that list?
The help page only mentions that "If a sketch no longer needs a library, simply delete its #include statements from the top of your code" but it does not mention how to remove the library from the list of contributed libraries.

Go to your Arduino documents directory; inside you will find a directory named "Libraries". The imported library directory will be there. Just delete it and restart the Arduino app.
Your Arduino library folder should look like this (on Windows):
My Documents\Arduino\libraries\ArduinoParty\ArduinoParty.cpp
My Documents\Arduino\libraries\ArduinoParty\ArduinoParty.h
My Documents\Arduino\libraries\ArduinoParty\examples
....
or like this (on Mac and Linux):
Documents/Arduino/libraries/ArduinoParty/ArduinoParty.cpp
Documents/Arduino/libraries/ArduinoParty/ArduinoParty.h
Documents/Arduino/libraries/ArduinoParty/examples
The only issue with unused libraries is the trivial amount of disk space they use. They aren't loaded automatically so don't take up any application memory of the Arduino IDE.

Quote from official documentation as of August 2013:
User-created libraries as of version 0017 go in a subdirectory of your default sketch directory. For example, on OSX, the new directory would be ~/Documents/Arduino/libraries/. On Windows, it would be My Documents\Arduino\libraries\. To add your own library, create a new directory in the libraries directory with the name of your library. The folder should contain a C or C++ file with your code and a header file with your function and variable declarations. It will then appear in the Sketch | Import Library menu in the Arduino IDE.
To remove a library, stop the Arduino IDE and remove the library directory from the aforementioned location.

The answer is only valid if you have not changed the "Sketchbook Location" field in Preferences. So, first, you need to open the Arduino IDE and go to the menu
"File -> Preferences"
In the dialog, look at the field "Sketchbook Location" and open the corresponding folder.
The "libraries" folder in inside.

I have found that from version 1.8.4 on, the libraries can be found in ~/Arduino/Libraries. Hope this helps anyone else.

I had to look for them in C:\Users\Dell\AppData\Local\Arduino15\
I had to take help from the "date created" and "date modified" attributes to identify which libraries to delete.
But the names still show in the IDE... But it is something I can live with for now.

For others who are looking to remove a built-in library, the route is to get into PackageContents -> Java -> libraries.
BUT : IT MAKES NO SENSE TO ELIMINATE LIBRARIES inside the app, they don't take space, don't have any influence on performance, and if you don't know what you are doing, you can harm the program.
I did it because Arduino told me about libraries to update, showing then a board I don't have, and when saying ok it wanted to install a lot of new dependencies - I just felt forced to something I don't want, so I deinstalled that board.

In Elegoo Super Starter Kit, Part 2, Lesson 2.12, IR Receiver Module, I hit the problem that the lesson's IRremote library has a hard conflict with the built-in Arduino RobotIRremote library. I am using the Win10 IDE App, and it was non-trivial to "move the RobotIRremote" folder like the pre-Win10 instructions said. The built-in Libraries are saved at a path like: C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.42.0_x86__mdqgnx93n4wtt\libraries
You won't be able to see WindowsApps unless you show hidden files, and you can't do anything in that folder structure until you are the owner. Carefully follow these directions to make that happen: https://www.youtube.com/watch?v=PmrOzBDZTzw
After hours of frustration, the process above finally resulted in success for me. Elegoo gets an F+ for modern instructions on this lesson.

as of 1.8.X IDE
C:\Users***\Documents\Arduino\Libraries\

My solution is low-tech but effective so I want to share:
create a folder for disabled libraries next to libraries
move libraries here to disable, swap back in to re-enable

Related

What to do if Processing won't find a library?

No matter what I do, Processing just won't find this library. No matter where I put it or how many renames I do, Processing can't find it and I can't find an alternative anywhere. I basically only need it for the "Descriptive" class. And I know its in the correct spot because I have the library "minim" and Processing can find that. The DL link.
Anyone want to give it a shot and then give a solution (or walkthrough of what/how they did) if they find whats wrong? Or know of another library where this class is at?
The simplest way to load a non-standard library into a Processing sketch is to drag the .jar file onto the Processing editor.
You don't have to install the library in the libraries directory. Just find a file like YourLibrary.jar and drag it directly onto your sketch in the Processing editor.
This will automatically put the library jar file in the correct place, and you'll be able to use the jar in your sketch.
Shameless self-promotion: here is a guide on using libraries in Processing.
It is possible that you are putting the library in the wrong folder, click Preferences in Processing and look for Sketchbook Location (which is where you should copy the downloaded folder in) to make sure you are putting it in the right place. I have checked the download link and the site says you have to copy the entire unzipped folder into your libraries folder (which is located in your sketchbook folder) in order for it to work.
If you have checked what I suggested above and still cannot find a problem, refer to https://github.com/processing/processing/wiki/How-to-Install-a-Contributed-Library which will hopefully help you.

add module in qt(QML module) [duplicate]

So when I create a new Qt project inside Qt Creator I'm only asked for some simple details like location of the project, build targets, the main window class name (along with header, source and form file) and at the enda choice to add it to version control.
After I create the project I'm only given the qt core and gui modules. My question is how do I add other modules (such as network or opengl). I've looked and looked, yet I cannot find anything on how to add other Qt modules easily. I know I can edit the .pro file, but unfortunately I don't know all the modules in Qt, nevermind the name I'm supposed to put there. Adding external libraries is easy, but how come there's no (obvious) option to add Qt libraries?
Help would be much appreciated ^_^ Thanks!
Oh yeah... I'm running Arch Linux if that's any help.
Edit your .pro file. It should has one line like this:
QT += core gui
Append the desired modules in this line. To get the module's names, just remove the "Qt" part in this list. (e.g. QtSql turns "sql")
I can't find that either.
It seems that in older versions of the "New project" wizard you used to be able to specify which modules you wanted to use, but even then you were not able to alter your choice later. And this seems gone now, so your only choice is to manually edit the .pro file.
As others have pointed out, you simply #include the module you want in the source and add the name of the module in the .pro file to the QT variable.
However the actual documentation you need which no one else has mentioned is the qmake Project Files page. qmake is very powerful and it's well worth getting familiar with how it works and I think that's why they don't provide a complete GUI for it, as it can handle some very complex scenarios.
You have to read the documentation to add the modules.
Frankly speaking, I never really felt like that there needs to be a GUI for that.

How to add an external library to QT?

I am trying to create a project assosiated with the SimConnect SDK.
I am new to QT, and in Visual Studio, I just had a SimConnect.h file, a .lib file, and a .dll file, and I managed to make it work. Now I am trying to create a C++ widget project, using the same SDK, but in QT.
I put the header file in my QT project's folder, where the other default code and header files are located, and then I went to the project and added them as existing files, as I read in Google. I'm having problems with the actual library.
I've been searching Google for a guide on how to add a library file to the project, I did some things I saw on the internet, like the LIBS line for example, but I probably did it wrong, even though it looked very simple.
I am not sure where to drop my dll/library files in the project directory, maybe the problem is I always put them in the wrong spot.
The furthest I got to, was an error message saying "Unresolved external symbol", and a red writing saying ".obj file not found" on every function I tried to use from the SimConnect functions, which probably means QT couldn't find my library/dll file.
I also tried to add the libraries from the "Add library" option in the project, but that didn't work too.
EDIT: it also warns "warning: LNK4272: library machine type 'X86' conflicts with target machine type 'x64'" maybe it has to do something with it.
(Posted on behalf of the OP).
Solved! My problem was my machine was set to 64bit, while the library was set to 32bit, so I downloaded the 32bit kit, and ran the project through that, and it worked!

Cannot find correct file called qtnetwork4.dll

Guys I've written app in qt and when trying to run it (double click on *.exe) I'm getting error that this application cannot start because qtnetwork4.dll isn't available. I've searched my drive and I found few files with this name (and copied one by one every time trying to run my app) but none of them seems to work. How can I solve it?
place into your *.exe - folder appropriate dll-s from %QT_PATH%\bin\
There is an app called Dependency Walker that will let you know what functions in qtnetwork4.dll are being used in your program. It can be found at the following:
http://www.dependencywalker.com/
All of the DLLs your program use will be from the same installation as the qmake.exe that is used to compile the program. If you are using Qt Creator you can see where the qmake.exe your using is located by going to:
tools->options->Qt4
Get the DLLs that are located at the path displayed here to make sure they will work with your program.
On windows, DLL are looked for in folder where executable lies, then using "PATH" environenment variable.
In your case, you want to put your dll along your executable, taking them from the sdk you're using to compile
The following page provides a lot of additional information on the subject (example, plugins, strategy for building installers)
To force using QtNetwork and linking it, you have to put
QT += network
in your poject file.
If you're sure you're not using it, you can use
QT -= network

How to make Qt aware of the QMYSQL driver

I'm trying to access a MySql database from a Qt application but I get the following error:
QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QSQLITE2
I find this very strange cause I have libqsqlmysql.so on my Qt folder. I have even tried to compile the MySql driver as a static plugin and add it to my .pro file as:
QTPLUGIN += qsqlmysql
But this also generates the same runtime error (it must've found the plugin cause there's no error compiling the application)
What am I missing? I would like to avoid having to compile Qt from source cause this will have to work seamlessly on the deploy machines as well.
BTW: Even though I'm developing and testing on Linux I will need to support Windows. Will I experience this same issue on Windows? How can I compile and link the MySql driver in both Linux and Windows?
The solution:
After following #Sergey's recommendations I did an strace of the application redirecting the output to grep so I could search for 'mysql' and for my surprise the application wasn't looking for the plugin at QTDIR/plugins/sqldrivers where I had libqsqlmysql.so, it was looking at QTDIR/lib. After copying the plugin to the lib folder the MySql connection worked.
Try opening the shared library with dlopen() and see if it loads and if not, what dlerror() tells you. I always run into similar problems on Windows. LoadLibrary()/GetLastError() saved me numerous times (last time it was because of a wrong version of some libiconv/libintl DLL). Running ldd on the plugin may also help.
If dlopen() works fine, try to load the plugin with QPluginLoader. If it doesn't load, then check the buildkey of the plugin. I usually do it the dirty way by running strings on the plugin and then looking for strings like "buildkey" or "QT_PLUGIN_VERIFICATION_DATA". Just looking at the build key and around it may give you an idea. For example, you may realize that you have compiled your plugin in the release mode while your application is compiled in the debug mode. In such case the build key won't match and the plugin won't load. Everything in the build key must match your configuration. Note that the version and the build key are checked differently: the build key must match exactly (or match some black magic called QT_BUILD_KEY_COMPAT), but in the version only the major version must match exactly, the minor version must be the version of Qt the plugin was compiled with or later and the patch level is ignored. So if your plugin was compiled with Qt 4.x.y then it will work with Qt versions 4.z.* where z>=x. This actually makes sense.
If the build key looks okay (which is unlikely if you got to this point), you may wish to look at QLibraryPrivate::isPlugin() source code to figure out what's wrong, but that doesn't look like an easy task to me (although running this in a debugger may help).
If QPluginLoader does load the plugin, check if it is in the right directory and has correct permissions. If you still didn't solve the problem by this point, it's time to look at the SQL module source code that actually loads these plugins. But it is extremely unlikely. I ran into this problem many, many times and it was always either the library not loading or the build key not matching.
Another way to go after QPluginLoader loads the plugin successfully is to use strace to figure out whether the program at least tries to open the plugin file. Searching for something like "sqldrivers" or "plugins" in the strace output should also give away the directory where Qt is searching for its plugins and specifically SQL drivers.
Update
Is it possible to compile the driver as a static plugin and don't worry about anything? Let's try:
d:\Qt4\src\plugins\sqldrivers\psql>qmake CONFIG+=static LIBS+=-Ld:/programs/Post
greSQL/lib INCLUDEPATH+=d:/programs/PostgreSQL/include
d:\Qt4\src\plugins\sqldrivers\psql>make
It compiles fine and now I got libqsqlpsql.a (release) and libqsqlpsqld.a (debug) in QTDIR/plugins/sqldrivers (it is the right place on Windows). I am using PostgreSQL driver here, but I don't think it will be any different for MySQL which I just don't have installed. Ok, let's compile some real program with it:
d:\alqualos\pr\archserv>qmake QTPLUGIN+=qsqlpsql PREFIX=d:/alqualos LIBS+=-Ld:/g
nu/lib INCLUDEPATH+=d:/gnu/include LIBS+=-Ld:/programs/PostgreSQL/lib LIBS+=-lpq
Note that I had to manually link to libpq, otherwise the linker would complain about undefined references. The funny thing is, qmake knows that qsqlpsql is located in QTDIR/plugins/sqldrivers and sets compiler and linker options accordingly. So it still needs to be in the right place to work, only you don't have to worry about your users running into the same problem as it is only used during compilation. An alternative would be to just use LIBS+=-Lpath/to/plugin LIBS+=-lqsqlpsql instead of QTPLUGIN+=qsqlpsql, at least the docs say that it should work, but I haven't tested it.
In order for the application to actually use the plugin I had to put the following in my main unit (CPP file):
#include <QtPlugin>
Q_IMPORT_PLUGIN(qsqlpsql)
It works! Also, from what I've been able to figure out from the sources, the build key and the version are checked only when a plugin is dynamically loaded (all the relevant stuff is in the QLibrary's private class, not even QPluginLoader's). So the resulting executable may (or may not, depending on the binary compatibility) work even with different versions and builds of Qt, although using it with older versions may trigger some bugs that were fixed later.
It is also worth noting that the order for loading SQL drivers is this: use the driver statically linked into Qt if available, then look for a driver registered manually with QSqlDatabase::registerSqlDriver(), then look for a driver statically imported into the application (the way described above), and finally try to load a shared plugin. So when you link statically, your users won't be able to use dynamically linked drivers they may already have, but will be able to use drivers linked statically into Qt (like in Ubuntu).
I compiled QT first and then realised that I need mysql as well. So I compiled mysql plugin by
executing following command in QT-DIR\src\plugins\sqldrivers\mysql folder.
Mysql plugin compile command
qmake "INCLUDEPATH+=$$quote(C:\Program Files\MySQL\MySQL Server 5.5\include)" "LIBS+=$$quote(C:\Program Files\MySQL\MySQL Server 5.5\lib\libmysql.lib)" mysql.pro
Plugings are then created in created in folder QT-DIR\plugins\sqldrivers.
However, when I tried to use it in my code. It failed with following error.
Error msg
QSqlDatabase: QMYSQLDriver driver not loaded
Solution
After some googling and checking Path variable I realised that the Mysql server lib
( C:\Program Files\MySQL\MySQL Server 5.5\lib) directory was not in my Path variable. I expect that the dll in this folder are used by the plugin at runtime. After including Mysql server lib in Path variable everything worked smoothly. Hope this information saves some hair on other programmers scalp, as I uprooted quite a few. :D
Last time I looked at this you needed to rebuild Qt from source and include the appropriate MySQL source.
Building Qt from the sources is not hard, it just takes a while. You are likely to have the required tools already.
A possible workaround may be to access the back-end over ODBC instead.
In order for your app to pick up the plugin at runtime, the shared library implementing the MySQL plugin needs to be placed in the correct directory. The best way of determining that directory is to check the output of QCoreApplication::libraryPaths. You can also force specific paths by using a qt.conf file.
Please note that plugins must be placed in subdirectories within the plugin path, and the final part of the path name (i.e., the parent directory of the shared libraries) cannot be changed. SQL drivers need to go in a directory named sqldrivers, i.e. <pluginpath>/sqldrivers. For more details on plugin directories, see How to Create Qt Plugins.
I was experiencing this same issue as well. I've been installing and experimenting with a lot of different Python tools and UIs. I then uninstalled everything python related. I did a fresh install of Python 3.2, PyQT 3.2, and Eric5. No more errors with the QMySQL driver.
well i have had this issue, and after a lot of time, and different tools, i found that QT ( on windows, have not been able to test on Linux.) loads the "QSQLMYSQL.." when requested, but before runtime the lib ("QSQLMYSQL..") file must reside on one of the searched paths (QApp.libraryPaths()) inside a folder called "sqldrivers".. otherwise QT will just ignore the file, even if it is at some other point inside the searched path.
what i did was to monitor the dependency of a sample app, and when i removed the "QSQLMYSQL.." dll from "plugins\sqldrivers\" it failed, but when i maded a folder inside the app folder, called "sqldrivers" and placed the "QSQLMYSQL..." inside there, it loaded.
what i have is mysql 5.5, qt 4.7.4.
hope anyone can use this, and if anyone knows more about it, i would like to know where to find it(http://doc.qt.nokia.com/stable/sql-driver.html, is the closest you can get to the information about the folder structur). :P
This may also happen if your QMYSQL plugin is linked against the "wrong" mysql_client.a or it isn't in the LD_LIBRARY_PATH. I had this problem on OSX because mysql was installed via ports, and I fixed it with:
install_name_tool -change libmysqlclient.18.dylib /usr/local/mysql/lib/libmysqlclient_r.18.dylib libqsqlmysql.dylib

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