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• ISO C++ forbids declaration of 'QPushButton' with no type in QT Creator

  - by Mohit Deshpande

  I am running QT Creator on a Linux Ubuntu 9.10 machine. I just got started with QT Creator, and I was going through the tutorials when this error popped up while I was trying to build my project: "ISO C++ forbids declaration of 'QPushButton' with no type". This problem appears in my header file: #ifndef MAINWINDOW_H #define MAINWINDOW_H #include <QtGui/QWidget> namespace Ui { class MainWindow; } class MainWindow : public QWidget { Q_OBJECT public: MainWindow(QWidget *parent = 0); ~MainWindow(); public slots: void addContact(); void submitContact(); void cancel(); private: Ui::MainWindow *ui; QPushButton *addButton; QPushButton *submitButton; QPushButton *cancelButton; QLineEdit *nameLine; QTextEdit *addressText; QMap<QString, QString> contacts; QString oldName; QString oldAddress; }; #endif // MAINWINDOW_H

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• Trying to make a plugin system in C++/Qt

  - by Pirate for Profit

  I'm making a task-based program that needs to have plugins. Tasks need to have properties which can be easily edited, I think this can be done with Qt's Meta-Object Compiler reflection capabilities (I could be wrong, but I should be able to stick this in a QtPropertyBrowser?) So here's the base: class Task : public QObject { Q_OBJECT public: explicit Task(QObject *parent = 0) : QObject(parent){} virtual void run() = 0; signals: void taskFinished(bool success = true); } Then a plugin might have this task: class PrinterTask : public Task { Q_OBJECT public: explicit PrinterTask(QObject *parent = 0) : Task(parent) {} void run() { Printer::getInstance()->Print(this->getData()); // fictional emit taskFinished(true); } inline const QString &getData() const; inline void setData(QString data); Q_PROPERTY(QString data READ getData WRITE setData) // for reflection } In a nutshell, here's what I want to do: // load plugin // find all the Tasks interface implementations in it // have user able to choose a Task and edit its specific Q_PROPERTY's // run the TASK It's important that one .dll has multiple tasks, because I want them to be associated by their module. For instance, "FileTasks.dll" could have tasks for deleting files, making files, etc. The only problem with Qt's plugin setup is I want to store X amount of Tasks in one .dll module. As far as I can tell, you can only load one interface per plugin (I could be wrong?). If so, the only possible way to do accomplish what I want is to create a FactoryInterface with string based keys which return the objects (as in Qt's Plug-And-Paint example), which is a terrible boilerplate that I would like to avoid. Anyone know a cleaner C++ plugin architecture than Qt's to do what I want? Also, am I safely assuming Qt's reflection capabilities will do what I want (i.e. able to edit an unknown dynamically loaded tasks' properties with the QtPropertyBrowser before dispatching)?

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• QT NOOB: Add action handler for multiple objects of same type.

  - by what

  I have a simple QT application with 10 radio buttons with names radio_1 through radio_10. It is a ui called Selector, and is part of a class called TimeSelector In my header file for this design, i have this: //! [1] class TimeSelector : public QWidget { Q_OBJECT public: TimeSelector(QWidget *parent = 0); private slots: //void on_inputSpinBox1_valueChanged(int value); //void on_inputSpinBox2_valueChanged(int value); private: Ui::Selector ui; }; //! [1] the commented out void_on_inputSpinBox1_valueChanged(int value) is from the tutorial for the simple calculator. I know i can do: void on_radio_1_valueChanged(int value); but I would need 10 functions. I want to be able to make one function that works for everything, and lets me pass in maybe a name of the radio button that called it, or a reference to the radio button so i can work with it and determine who it was. I am very new to QT but this seems like it should be very basic and doable, thanks.

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• Simple POSIX threads question

  - by Andy

  Hi, I have this POSIX thread: void subthread(void) { while(!quit_thread) { // do something ... // don't waste cpu cycles if(!quit_thread) usleep(500); } // free resources ... // tell main thread we're done quit_thread = FALSE; } Now I want to terminate subthread() from my main thread. I've tried the following: quit_thread = TRUE; // wait until subthread() has cleaned its resources while(quit_thread); But it does not work! The while() clause does never exit although my subthread clearly sets quit_thread to FALSE after having freed its resources! If I modify my shutdown code like this: quit_thread = TRUE; // wait until subthread() has cleaned its resources while(quit_thread) usleep(10); Then everything is working fine! Could someone explain to me why the first solution does not work and why the version with usleep(10) suddenly works? I know that this is not a pretty solution. I could use semaphores/signals for this but I'd like to learn something about multithreading, so I'd like to know why my first solution doesn't work. Thanks!

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• x86 Assembly: Before Making a System Call on Linux Should You Save All Registers?

  - by mudge

  I have the below code that opens up a file, reads it into a buffer and then closes the file. The close file system call requires that the file descriptor number be in the ebx register. The ebx register gets the file descriptor number before the read system call is made. My question is should I save the ebx register on the stack or somewhere before I make the read system call, (could int 80h trash the ebx register?). And then restore the ebx register for the close system call? Or is the code I have below fine and safe? I have run the below code and it works, I'm just not sure if it is generally considered good assembly practice or not because I don't save the ebx register before the int 80h read call. ;; open up the input file mov eax,5 ; open file system call number mov ebx,[esp+8] ; null terminated string file name, first command line parameter mov ecx,0o ; access type: O_RDONLY int 80h ; file handle or negative error number put in eax test eax,eax js Error ; test sign flag (SF) for negative number which signals error ;; read in the full input file mov ebx,eax ; assign input file descripter mov eax,3 ; read system call number mov ecx,InputBuff ; buffer to read into mov edx,INPUT_BUFF_LEN ; total bytes to read int 80h test eax,eax js Error ; if eax is negative then error jz Error ; if no bytes were read then error add eax,InputBuff ; add size of input to the begining of InputBuff location mov [InputEnd],eax ; assign address of end of input ;; close the input file ;; file descripter is already in ebx mov eax,6 ; close file system call number int 80h

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• Trying to make a plugin system in C++

  - by Pirate for Profit

  I'm making a task-based program that needs to have plugins. Tasks need to have properties which can be easily edited, I think this can be done with Qt's Meta-Object Compiler reflection capabilities (I could be wrong, but I should be able to stick this in a QtPropertyBrowser?) So here's the base: class Task : public QObject { Q_OBJECT public: explicit Task(QObject *parent = 0) : QObject(parent){} virtual void run() = 0; signals: void taskFinished(bool success = true); } Then a plugin might have this task: class PrinterTask : public Task { Q_OBJECT public: explicit PrinterTask(QObject *parent = 0) : Task(parent) {} void run() { Printer::getInstance()->Print(this->getData()); // fictional emit taskFinished(true); } inline const QString &getData() const; inline void setData(QString data); Q_PROPERTY(QString data READ getData WRITE setData) // for reflection } In a nutshell, here's what I want to do: // load plugin // find all the Tasks interface implementations in it // have user able to choose a Task and edit its specific Q_PROPERTY's // run the TASK It's important that one .dll has multiple tasks, because I want them to be associated by their module. For instance, "FileTasks.dll" could have tasks for deleting files, making files, etc. The only problem with Qt's plugin setup is I want to store X amount of Tasks in one .dll module. As far as I can tell, you can only load one interface per plugin (I could be wrong?). If so, the only possible way to do accomplish what I want is to create a FactoryInterface with string based keys which return the objects (as in Qt's Plug-And-Paint example), which is a terrible boilerplate that I would like to avoid. Anyone know a cleaner C++ plugin architecture than Qt's to do what I want? Also, am I safely assuming Qt's reflection capabilities will do what I want (i.e. able to edit an unknown dynamically loaded tasks' properties with the QtPropertyBrowser before dispatching)?

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• one key multiple values from different sources c#

  - by user2964034

  I am trying to make a c# program that will compare two files for me, and tell me the differences of specific parts. I have been able to get the parts I need into variables while looping through, but I now want to add these to a key with 3 values per file, so a key with 6 values overall which I will then compare to eachother later on. But I can only add 3 values at a time using the loop I have, so I need to be able to add the last 3 values to the key without overwriting the first 3. example of data from file: [\Advanced\Rules\Correlation Rules\Suspect_portscan\]; CheckDescription =S Detect Port scans; Enabled =B 0; Priority =L 3; I have managed to get what I need into variables so I have: string SigName would be "Suspect_portscan" Int Enabled, Priority, Blocking as 0 3 and null respectivly. I then want to make a dictionary type thing, with a key which would be the SigName and the first 3 values as enabled, priority, blocking. Then when looping through the second file, I want to add the 2nd files settings for the enabled, priority, blocking for the same SigName (so to the key) in the last 3 value slots. I will then compare this against itself, like 'if signame(0) != signame(3)' so if file 1 enabled is not the same as file two enabled make a note and tell me. But the problem I have is not being able to get the data into a dictionary or lookup, I'm completely stumped. It seems like I should use a dictionary with a list for the values but I cant get it working on the second loop through. Thanks.

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• C++: defining maximum/minimum limits for a class

  - by Luis

  Basically what the title says... I have created a class that models time slots in a variable-granularity daily schedule (where for example the first time slot is 30 minutes, but the second time slot can be 40 minutes); the first available slot starts at (a value comparable to) 1. What I want to do now is to define somehow the maximum and minimum allowable values that this class takes and I have two practical questions in order to do so: 1.- does it make sense to define absolute minimum and maximum in such a way for a custom class? Or better, does it suffice that a value always compares as lower-than any other possible value of the type, given the class's defined relational operators, to be defined the min? (and analogusly for the max) 2.- assuming the previous question has an answer modeled after "yes" (or "yes but ..."), how do I define such max/min? I know that there is std::numeric_limits<> but from what I read it is intended for "numeric types". Do I interpret that as meaning "represented as a number" or can I make a broader assumption like "represented with numbers" or "having a correspondence to integers"? After all, it would make sense to define the minimum and maximum for a date class, and maybe for a dictionary class, but numeric_limits may not be intended for those uses (I don't have much experience with it). Plus, numeric_limits has a lot of extra members and information that I don't know what to make with. If I don't use numeric_limits, what other well-known / widely-used mechanism does C++ offer to indicate the available range of values for a class?

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• C Programming. How to deep copy a struct?

  - by user69514

  I have the following two structs where "child struct" has a "rusage struct" as an element. Then I create two structs of type "child" let's call them childA and childB How do I copy just the rusage struct from childA to childB? typedef struct{ int numb; char *name; pid_t pid; long userT; long systemT; struct rusage usage; }child; typedef struct{ struct timeval ru_utime; /* user time used */ struct timeval ru_stime; /* system time used */ long ru_maxrss; /* maximum resident set size */ long ru_ixrss; /* integral shared memory size */ long ru_idrss; /* integral unshared data size */ long ru_isrss; /* integral unshared stack size */ long ru_minflt; /* page reclaims */ long ru_majflt; /* page faults */ long ru_nswap; /* swaps */ long ru_inblock; /* block input operations */ long ru_oublock; /* block output operations */ long ru_msgsnd; /* messages sent */ long ru_msgrcv; /* messages received */ long ru_nsignals; /* signals received */ long ru_nvcsw; /* voluntary context switches */ long ru_nivcsw; /* involuntary context switches */ }rusage; I did the following, but I guess it copies the memory location, because if I changed the value of usage in childA, it also changes in childB. memcpy(&childA,&childB, sizeof(rusage)); I know that gives childB all the values from childA. I have already taken care of the others fields in childB, I just need to be able to copy the rusage struct called usage that resides in the "child" struct.

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• Robotlegs: Warning: Injector already has a rule for type

  - by MikeW

  I have a bunch of warning messages like this appear when using Robotlegs/Signals. Everytime this command class executes, which is every 2-3 seconds ..this message displays below If you have overwritten this mapping intentionally you can use "injector.unmap()" prior to your replacement mapping in order to avoid seeing this message. Warning: Injector already has a rule for type "mx.messaging.messages::IMessage", named "". The command functions fine otherwise but I think I'm doing something wrong anyhow. public class MessageReceivedCommand extends SignalCommand { [Inject] public var message:IMessage; ...etc.. do something with message.. } the application context doesnt map IMessage to this command, as I only see an option to mapSignalClass , besides the payload is received fine. Wonder if anyone knows how I might either fix or suppress this message. I've tried calling this as the warning suggests injector.unmap(IMessage, "") but I receive an error - no mapping found for ::IMessage named "". Thanks Edit: A bit more info about the error Here is the signal that I dispatch to the command public class GameMessageSignal extends Signal { public function GameMessageSignal() { super(IMessage); } } which is dispatched from a IPushDataService class gameMessage.dispatch(message.message); and the implementation is wired up in the app context via injector.mapClass(IPushDataService, PushDataService); along with the signal signalCommandMap.mapSignalClass(GameMessageSignal, MessageReceivedCommand); Edit #2: Probably good to point out also I inject an instance of GameMessageSignal into IPushDataService public class PushDataService extends BaseDataService implements IPushDataService { [Inject] public var gameMessage:GameMessageSignal; //then private function processMessage(message:MessageEvent):void { gameMessage.dispatch(message.message); } } Edit:3 The mappings i set up in the SignalContext: injector.mapSingleton(IPushDataService); injector.mapClass(IPushDataService, PushDataService);

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• error: expected ',' or '...' before numeric constant

  - by goldfrapp04

  Just a Qt Gui Application with QDialog as the Base Class, the simplest type you can expect. I've programmed on Qt for several times but this is the first time I meet this problem... I've added minimal code to the program, and here's the code in dialog.h (which is mostly automatically generated) #ifndef DIALOG_H #define DIALOG_H #include <QDialog> #include <QPixmap> #include "bmp.h" namespace Ui { class Dialog; } class Dialog : public QDialog { Q_OBJECT public: explicit Dialog(QWidget *parent = 0); ~Dialog(); private slots: void on_openButton_clicked(); private: Ui::Dialog *ui; BMP srcImage; QImage compressedImage[3]; }; #endif // DIALOG_H While I edit, the "public:" is underlined and says "unexpected token '('". When I try to build the program, it says in the line "Q_OBJECT", "error: expected ',' or '...' before numeric constant". I'm sure I've defined nothing related to it (to be exact, I defined an N and an n in file bmp.h, both are int). Any idea of what's wrong here? Thanks.

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• C++ variable to const expression

  - by user1344784

  template <typename Real> class A{ }; template <typename Real> class B{ }; //... a few dozen more similar template classes class Computer{ public slots: void setFrom(int from){ from_ = from; } void setTo(int to){ to_ = to; } private: template <int F, int T> void compute(){ using boost::fusion::vector; using boost::fusion::at_c; vector<A<float>, B<float>, ...> v; at_c<from_>(v).operator()(at_c<to_>(v)); //error; needs to be const-expression. }; This question isn't about Qt, but there is a line of Qt code in my example. The setFrom() and setTo() are functions that are called based on user selection via the GUI widget. The root of my problem is that 'from' and 'to' are variables. In my compute member function I need to pick a type (A, B, etc.) based on the values of 'from' and 'to'. The only way I know how to do what I need to do is to use switch statements, but that's extremely tedious in my case and I would like to avoid. Is there anyway to convert the error line to a constant-expression?

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• pthread_create followed by pthread_detach still results in possibly lost error in Valgrind.

  - by alesplin

  I'm having a problem with Valgrind telling me I have some memory possible lost: ==23205== 544 bytes in 2 blocks are possibly lost in loss record 156 of 265 ==23205== at 0x6022879: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==23205== by 0x540E209: allocate_dtv (in /lib/ld-2.12.1.so) ==23205== by 0x540E91D: _dl_allocate_tls (in /lib/ld-2.12.1.so) ==23205== by 0x623068D: pthread_create@@GLIBC_2.2.5 (in /lib/libpthread-2.12.1.so) ==23205== by 0x758D66: MTPCreateThreadPool (MTP.c:290) ==23205== by 0x405787: main (MServer.c:317) The code that creates these threads (MTPCreateThreadPool) basically gets an index into a block of waiting pthread_t slots, and creates a thread with that. TI becomes a pointer to a struct that has a thread index and a pthread_t. (simplified/sanitized): for (tindex = 0; tindex < NumThreads; tindex++) { int rc; TI = &TP->ThreadInfo[tindex]; TI->ThreadID = tindex; rc = pthread_create(&TI->ThreadHandle,NULL,MTPHandleRequestsLoop,TI); /* check for non-success that I've omitted */ pthread_detach(&TI->ThreadHandle); } Then we have a function MTPDestroyThreadPool that loops through all the threads we created and cancels them (since the MTPHandleRequestsLoop doesn't exit). for (tindex = 0; tindex < NumThreads; tindex++) { pthread_cancel(TP->ThreadInfo[tindex].ThreadHandle); } I've read elsewhere (including other questions here on SO) that detaching a thread explicitly would prevent this possibly lost error, but it clearly isn't. Any thoughts?

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• Measure text size in JavaScript

  - by kayahr

  I want to measure the size of a text in JavaScript. So far this isn't so difficult because I can simply put a temporary invisible div into the DOM tree and check the offsetWidth and offsetHeight. The problem is, I want to do this BEFORE the DOM is ready. Here is a stub: <html> <head> <script type="text/javascript"> var text = "Hello world"; var fontFamily = "Arial"; var fontSize = 12; var size = measureText(text, fontSize, fontFamily); function measureText(text, fontSize, fontFamily) { // TODO Implement me! } </script> </head> <body> </body> </html> Again: I KNOW how to do it asynchronously when DOM (or body) signals that it is ready. But I want to do it synchronously right in the header as shown in the stub above. Any ideas how I can accomplish this? My current opinion is that this is impossible but maybe someone has a crazy idea.

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• C++ MFC server app with sockets crashes and I cannot find the fault, help!

  - by usermeister

  My program has one dialog and two sockets. Both sockets are derived from CAsyncSocket, one is for listening, other is for receiving data from client. My program crashes when client tries to connect to server application and server needs to initialize receiving socket. This is my MFC dialog class. class CFileTransferServerDlg : public CDialog { ... ListeningSocket ListenSock; ReceivingSocket* RecvSock; void OnAccept(); // called when ListenSock gets connection attempt ... }; This is my derived socket class for receiving data that calls parent dialogs method when event is signaled. class ReceivingSocket : public CAsyncSocket { CFileTransferServerDlg* m_pDlg; // for accessing parent dialogs controls virtual void OnReceive(int nErrorCode); } ReceivingSocket::ReceivingSocket() { } This is dialogs function that handles incoming connection attempt when listening socket gets event notification. This is where the crash happens. void CFileTransferServerDlg::OnAccept() { RecvSock = new ReceivingSocket; /* CRASH */ } OR void CFileTransferServerDlg::OnAccept() { ReceivingSocket* tmpSock = new ReceivingSocket; tmpSock->SetParentDlg(this); CString message; if( ListenSock.Accept(*tmpSock) ) /* CRASH */ { message.LoadStringW(IDS_CLIENT_CONNECTED); m_txtStatus.SetWindowTextW(message); RecvSock = tmpSock; } } My program crashes when I try to create a socket for receiving file sent from client application. OnAccept starts when Listening socket signals incoming connection attempt, but my application then crashes. I've tried running it on another computer and connection attempt was succesful. What could be wrong? Error in debug mode: Unhandled exception at 0x009c30e1 in FileTransferServer.exe: 0xC0000005: Access violation reading location 0xccccce58.

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• Good functions and techniques for dealing with haskell tuples?

  - by toofarsideways

  I've been doing a lot of work with tuples and lists of tuples recently and I've been wondering if I'm being sensible. Things feel awkward and clunky which for me signals that I'm doing something wrong. For example I've written three convenience functions for getting the first, second and third value in a tuple of 3 values. Is there a better way I'm missing? Are there more general functions that allow you to compose and manipulate tuple data? Here are some things I am trying to do that feel should be generalisable. Extracting values: Do I need to create a version of fst,snd,etc... for tuples of size two, three, four and five, etc...? fst3(x,_,_) = x fst4(x,_,_,_) = x Manipulating values: Can you increment the last value in a list of pairs and then use that same function to increment the last value in a list of triples? Zipping and Unzipping values: There is a zip and a zip3. Do I also need a zip4? or is there some way of creating a general zip function? Sorry if this seems subjective, I honestly don't know if this is even possible or if I'm wasting my time writing 3 extra functions every time I need a general solution. Thank you for any help you can give!

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• Django: How to override a related sets "add" method?

  - by MB_

  I am working on a django project and i want to send a signal when something get's added to some models related set, e.g. we have an owner wo has a set of collectables and each time the method owner.collectable_set.add(something) is getting called i want signal like "collectable_added" or something. signals are clear to me, but in which manager(?) the "add" method sits that i want to override is unclear to me. edit: Upon the request of Xaver to provide more details. You can easily override a models "save" method, by simply defining it and calling the super-"save" so it get's properly saved with some extra functionality for example. But i wonder where to override a related sets "add" method. gosh, i think i haven't brought in any further details. but i think it even should be clear what i want to do from the first paragraph. edit2: This is the method i want to override. Is it recommended to do so or do you suggest another way to place the sending of the signal?

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• What is the fastest (to access) struct-like object in Python?

  - by DNS

  I'm optimizing some code whose main bottleneck is running through and accessing a very large list of struct-like objects. Currently I'm using namedtuples, for readability. But some quick benchmarking using 'timeit' shows that this is really the wrong way to go where performance is a factor: Named tuple with a, b, c: >>> timeit("z = a.c", "from __main__ import a") 0.38655471766332994 Class using __slots__, with a, b, c: >>> timeit("z = b.c", "from __main__ import b") 0.14527461047146062 Dictionary with keys a, b, c: >>> timeit("z = c['c']", "from __main__ import c") 0.11588272541098377 Tuple with three values, using a constant key: >>> timeit("z = d[2]", "from __main__ import d") 0.11106188992948773 List with three values, using a constant key: >>> timeit("z = e[2]", "from __main__ import e") 0.086038238242508669 Tuple with three values, using a local key: >>> timeit("z = d[key]", "from __main__ import d, key") 0.11187358437882722 List with three values, using a local key: >>> timeit("z = e[key]", "from __main__ import e, key") 0.088604143037173344 First of all, is there anything about these little timeit tests that would render them invalid? I ran each several times, to make sure no random system event had thrown them off, and the results were almost identical. It would appear that dictionaries offer the best balance between performance and readability, with classes coming in second. This is unfortunate, since, for my purposes, I also need the object to be sequence-like; hence my choice of namedtuple. Lists are substantially faster, but constant keys are unmaintainable; I'd have to create a bunch of index-constants, i.e. KEY_1 = 1, KEY_2 = 2, etc. which is also not ideal. Am I stuck with these choices, or is there an alternative that I've missed?

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• Qtimer not timing out QT, C++

  - by realz

  Hi, I am learning C++ and using QT. I have a small program in which I am trying to update the text of the PushButton every second. The label being current time. I have a timer that should time out every second, but seems like it never does. here's the code. Header File #ifndef _HELLOFORM_H #define _HELLOFORM_H #include "ui_HelloForm.h" class HelloForm : public QDialog { public: HelloForm(); virtual ~HelloForm(); public slots: void textChanged(const QString& text); void updateCaption(); private: Ui::HelloForm widget; }; #endif /* _HELLOFORM_H */ CPP file #include "HelloForm.h" #include <QTimer> #include <QtGui/QPushButton> #include <QTime> HelloForm::HelloForm(){ widget.setupUi(this); widget.pushButton->setText(QTime::currentTime().toString()); widget.pushButton->setFont(QFont( "Times", 9, QFont::Bold ) ); QTimer *timer = new QTimer(this); connect(timer, SIGNAL(timeout()), SLOT(updateCaption())); timer->start(1000); connect(widget.pushButton, SIGNAL(clicked()), qApp, SLOT(quit()) ); connect(widget.nameEdit, SIGNAL(textChanged(const QString&)), this, SLOT(textChanged(const QString&))); } HelloForm::~HelloForm() { } void HelloForm::textChanged(const QString& text) { if (0 < text.trimmed().length()) { widget.helloEdit->setText("Hello " + text.trimmed() + "!"); } else { widget.helloEdit->clear(); } } void HelloForm::updateCaption() { QString myVar; myVar = QTime::currentTime().toString(); widget.pushButton->setText(myVar); } Any help will be greatly appreciated... The PushButton's text never changes...

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• Looking for PyQt4 embeddable terminal widget

  - by redShadow

  I wrote an application that, among other things, launches some "backend" processes to do some stuff. These subprocesses are very likely to fail or have unexpected behavior since they have to operate in quite hard conditions, so I prefer to give full control over them to the operator. NOTE: I am running these processes using a subprocess module based class instead of QProcess to have some more control functionality over the running process. At the moment, I'm using a QPlainTextEdit widget to which I append standard output/error from the subprocess, plus some buttons to quickly send some common signals (INT, STOP, CONT, KILL, ..), but: In some cases it would be useful to send some input too. Although it could be done with a text input box, I would prefer using something more "professional" Of course, there is no direct way to interpret special control characters, such as color codes, cursor movement, etc.. I had to implement an auto-scroll management of the console, but it is not guaranteed 100% to work nicely (sometimes the scroll locking doesn't work as expected, etc.) So: does anyone know something I could use to accomplish these needs? I found qtermwidget but it seems more oriented on handling a shell process (and the Python bindings seems to let you run /bin/bash only) by itself than communicating with an already existing process I/O.

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• OSI Model

  - by kaleidoscope

  The Open System Interconnection Reference Model (OSI Reference Model or OSI Model) is an abstract description for layered communications and computer network protocol design. In its most basic form, it divides network architecture into seven layers which, from top to bottom, are the Application, Presentation, Session, Transport, Network, Data Link, and Physical Layers. It is therefore often referred to as the OSI Seven Layer Model. A layer is a collection of conceptually similar functions that provide services to the layer above it and receives service from the layer below it. Description of OSI layers: Layer 1: Physical Layer ·         Defines the electrical and physical specifications for devices. In particular, it defines the relationship between a device and a physical medium. ·         Establishment and termination of a connection to a communications medium. ·         Participation in the process whereby the communication resources are effectively shared among multiple users. ·         Modulation or conversion between the representation of digital data in user equipment and the corresponding signals transmitted over a communications channel. Layer 2: Data Link Layer ·         Provides the functional and procedural means to transfer data between network entities. ·         Detect and possibly correct errors that may occur in the Physical Layer. The error check is performed using Frame Check Sequence (FCS). ·         Addresses is then sought to see if it needs to process the rest of the frame itself or whether to pass it on to another host. ·         The Layer is divided into two sub layers: The Media Access Control (MAC) layer and the Logical Link Control (LLC) layer. ·         MAC sub layer controls how a computer on the network gains access to the data and permission to transmit it. ·         LLC layer controls frame synchronization, flow control and error checking.   Layer 3: Network Layer ·         Provides the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks. ·         Performs network routing functions, and might also perform fragmentation and reassembly, and report delivery errors. ·         Network Layer Routers operate at this layer—sending data throughout the extended network and making the Internet possible.   Layer 4: Transport Layer ·         Provides transparent transfer of data between end users, providing reliable data transfer services to the upper layers. ·         Controls the reliability of a given link through flow control, segmentation/de-segmentation, and error control. ·         Transport Layer can keep track of the segments and retransmit those that fail. Layer 5: Session Layer ·         Controls the dialogues (connections) between computers. ·         Establishes, manages and terminates the connections between the local and remote application. ·         Provides for full-duplex, half-duplex, or simplex operation, and establishes checkpointing, adjournment, termination, and restart procedures. ·         Implemented explicitly in application environments that use remote procedure calls. Layer 6: Presentation Layer ·         Establishes a context between Application Layer entities, in which the higher-layer entities can use different syntax and semantics, as long as the presentation service understands both and the mapping between them. The presentation service data units are then encapsulated into Session Protocol data units, and moved down the stack. ·         Provides independence from differences in data representation (e.g., encryption) by translating from application to network format, and vice versa. The presentation layer works to transform data into the form that the application layer can accept. This layer formats and encrypts data to be sent across a network, providing freedom from compatibility problems. It is sometimes called the syntax layer. Layer 7: Application Layer ·         This layer interacts with software applications that implement a communicating component. ·         Identifies communication partners, determines resource availability, and synchronizes communication. o       When identifying communication partners, the application layer determines the identity and availability of communication partners for an application with data to transmit. o       When determining resource availability, the application layer must decide whether sufficient network or the requested communication exists. o       In synchronizing communication, all communication between applications requires cooperation that is managed by the application layer. Technorati Tags: Kunal,OSI,Networking

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• Save the Date - Oracle Partner Community Forum: Exadata, Exalogic and Manageability, Vienna, 23-24 April 2013

  - by Javier Puerta

  Hardware and Software Engineered to Work Together .Ritu { font-family: Arial, Helvetica, sans-serif; } .Ritu { font-family: Arial, Helvetica, sans-serif; } .Ritu { font-family: Arial, Helvetica, sans-serif; } body,td,th { font-family: Arial, Helvetica, sans-serif; font-size: x-small; } .color { color: #F00; } .c { color: #F00; } .c { color: #F00; } .c { color: #000; font-size: xx-small; } .c a { color: #F00; } .c { color: #F00; } .cl { color: #F00; } .b { color: #000; font-size: xx-small; } .i { font-style: italic; } .i { font-style: italic; } .i { font-style: italic; } .i { font-style: italic; } .i { font-style: italic; } .c { color: #F00; font-size: small; } .b { font-weight: bold; font-size: x-small; } .c { color: #F00; font-size: x-small; } .clr { color: #F00; } .c { color: #F00; } inside the Click Here The order you must follow to make the colored link appear in browsers. If not the default window link will appear 1. Select the word you want to use for the link 2. Select the desired color, Red, Black, etc 3. Select bold if necessary ___________________________________________________________________________________________________________________ Templates use two sizes of fonts and the sans-serif font tag for the email. All Fonts should be (Arial, Helvetica, sans-serif) tags Normal size reading body fonts should be set to the size of 2. Small font sizes should be set to 1 !!!!!!!DO NOT USE ANY OTHER SIZE FONT FOR THE EMAILS!!!!!!!! ___________________________________________________________________________________________________________________ -- Oracle PartnerNetwork | Account | Feedback SAVE THE DATE ORACLE PARTNER COMMUNITY FORUM: EXADATA, EXALOGIC AND MANAGEABILITY 23-24 APRIL 2013, VIENNA, AUSTRIA The 2013 event expands its scope to cover all the building blocks of the Cloud infrastructure: Exadata, Exalogic and Manageability! Dear partner I am delighted to announce the 2013 edition of the Exadata, Exalogic and Manageability Partner Community Forum for EMEA partners which will take place in Vienna, Austria, on April 23-24, 2013. After the experience of last year where we ran a joint Exadata and Manageability event, we received requests from many of you to add also Exalogic to the scope of the forum, and this way to cover the complete infrastructure architecture on the Exa platform. The continued market adoption of Exadata and Exalogic is being paralleled by a growth in the rate of projects sold and implemented by partners. Sharing customer cases and best-practices presented by other partners constitutes the core of this event. If you want to present an experience of your company around Exadata, Exalogic or Manageability that can be a learning experience for other partners, we still have some slots in the agenda. (Please contact Javier Puerta if you want to present.) Attending the Community Forum you will also have the opportunity to get Oracle’s insight on new products and market trends. And, of course, interact with the Oracle executives responsible for the Exadata, Exalogic and Manageability business. The atmosphere of beautiful Vienna will be the scenario of the event. Detailed venue and hotel booking information will be sent to you in January. Don't miss out on attending this key event! Save the date now - 23 & 24 April 2013, and watch out for your formal invitation coming soon. Kind regards, Javier Puerta Core Technology Partner Programs, Oracle EMEA E-Mail: [email protected] Jürgen Kress SOA Partner Adoption Oracle EMEA E-Mail: [email protected] Copyright © 2012, Oracle and/or its affiliates. All rights reserved. Contact PBC | Legal Notices and Terms of Use | Privacy Oracle Corporation - Worldwide Headquarters, 500 Oracle Parkway, OPL - E-mail Services, Redwood Shores, CA 94065, United States

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• Save the Date - Oracle Partner Community Forum: Exadata, Exalogic and Manageability, Vienna, 23-24 April 2013

  - by Javier Puerta

  Hardware and Software Engineered to Work Together .Ritu { font-family: Arial, Helvetica, sans-serif; } .Ritu { font-family: Arial, Helvetica, sans-serif; } .Ritu { font-family: Arial, Helvetica, sans-serif; } body,td,th { font-family: Arial, Helvetica, sans-serif; font-size: x-small; } .color { color: #F00; } .c { color: #F00; } .c { color: #F00; } .c { color: #000; font-size: xx-small; } .c a { color: #F00; } .c { color: #F00; } .cl { color: #F00; } .b { color: #000; font-size: xx-small; } .i { font-style: italic; } .i { font-style: italic; } .i { font-style: italic; } .i { font-style: italic; } .i { font-style: italic; } .c { color: #F00; font-size: small; } .b { font-weight: bold; font-size: x-small; } .c { color: #F00; font-size: x-small; } .clr { color: #F00; } .c { color: #F00; } inside the Click Here The order you must follow to make the colored link appear in browsers. If not the default window link will appear 1. Select the word you want to use for the link 2. Select the desired color, Red, Black, etc 3. Select bold if necessary ___________________________________________________________________________________________________________________ Templates use two sizes of fonts and the sans-serif font tag for the email. All Fonts should be (Arial, Helvetica, sans-serif) tags Normal size reading body fonts should be set to the size of 2. Small font sizes should be set to 1 !!!!!!!DO NOT USE ANY OTHER SIZE FONT FOR THE EMAILS!!!!!!!! ___________________________________________________________________________________________________________________ -- Oracle PartnerNetwork | Account | Feedback SAVE THE DATE ORACLE PARTNER COMMUNITY FORUM: EXADATA, EXALOGIC AND MANAGEABILITY 23-24 APRIL 2013, VIENNA, AUSTRIA The 2013 event expands its scope to cover all the building blocks of the Cloud infrastructure: Exadata, Exalogic and Manageability! Dear partner I am delighted to announce the 2013 edition of the Exadata, Exalogic and Manageability Partner Community Forum for EMEA partners which will take place in Vienna, Austria, on April 23-24, 2013. After the experience of last year where we ran a joint Exadata and Manageability event, we received requests from many of you to add also Exalogic to the scope of the forum, and this way to cover the complete infrastructure architecture on the Exa platform. The continued market adoption of Exadata and Exalogic is being paralleled by a growth in the rate of projects sold and implemented by partners. Sharing customer cases and best-practices presented by other partners constitutes the core of this event. If you want to present an experience of your company around Exadata, Exalogic or Manageability that can be a learning experience for other partners, we still have some slots in the agenda. (Please contact Javier Puerta if you want to present.) Attending the Community Forum you will also have the opportunity to get Oracle’s insight on new products and market trends. And, of course, interact with the Oracle executives responsible for the Exadata, Exalogic and Manageability business. The atmosphere of beautiful Vienna will be the scenario of the event. Detailed venue and hotel booking information will be sent to you in January. Don't miss out on attending this key event! Save the date now - 23 & 24 April 2013, and watch out for your formal invitation coming soon. Kind regards, Javier Puerta Core Technology Partner Programs, Oracle EMEA E-Mail: [email protected] Jürgen Kress SOA Partner Adoption Oracle EMEA E-Mail: [email protected] Copyright © 2012, Oracle and/or its affiliates. All rights reserved. Contact PBC | Legal Notices and Terms of Use | Privacy Oracle Corporation - Worldwide Headquarters, 500 Oracle Parkway, OPL - E-mail Services, Redwood Shores, CA 94065, United States

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• LSI SAS 9240-8i on Ubuntu 12.04 Hangs on Modprobe

  - by Francois Stark

  I used the LSI 9240-8i card on a smaller Intel motherboard with no problems in Ubuntu, with ZFS. However, we rebuilt the server to allow for more disks, using the ASROCK X79 Extreme 11 motherboard. It has 7 PCIe slots, and a LSI 2008 on-board. At first I thought the LSI 9240, when plugged in to PCIe, clashed with the on-board LSI 2008. Every time I plugged in the LSI 9240, modprobe would hang. Then I completely disabled the on-board LSI 2008, and the problem persisted. Last night it booted perfectly ONCE - all LSI cards and connected disks visible... However, all subsequent reboots failed. Both LSI cards' bios scans appear and they both see the disks connected to them, but Ubuntu modprobe hangs. Some selected dmesg lines, with both LSI cards enabled: [ 190.752100] megasas: [ 0]waiting for 1 commands to complete [ 195.772071] megasas: [ 5]waiting for 1 commands to complete [ 200.792079] megasas: [10]waiting for 1 commands to complete [ 205.812078] megasas: [15]waiting for 1 commands to complete [ 210.832037] megasas: [20]waiting for 1 commands to complete [ 215.852077] megasas: [25]waiting for 1 commands to complete [ 220.872072] megasas: [30]waiting for 1 commands to complete [ 225.892078] megasas: [35]waiting for 1 commands to complete [ 230.912086] megasas: [40]waiting for 1 commands to complete [ 235.932075] megasas: [45]waiting for 1 commands to complete [ 240.306157] usb 2-1.5: USB disconnect, device number 7 [ 240.952076] megasas: [50]waiting for 1 commands to complete [ 240.960034] INFO: task modprobe:233 blocked for more than 120 seconds. [ 240.960055] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 240.960067] modprobe D ffffffff81806200 0 233 146 0x00000004 [ 240.960075] ffff880806ae3b48 0000000000000086 ffff880806ae3ae8 ffffffff8101adf3 [ 240.960083] ffff880806ae3fd8 ffff880806ae3fd8 ffff880806ae3fd8 0000000000013780 [ 240.960090] ffffffff81c0d020 ffff880806acae00 ffff880806ae3b58 ffff880808961720 [ 240.960096] Call Trace: [ 240.960107] [<ffffffff8101adf3>] ? native_sched_clock+0x13/0x80 [ 240.960116] [<ffffffff816579cf>] schedule+0x3f/0x60 [ 240.960137] [<ffffffffa00093f5>] megasas_issue_blocked_cmd+0x75/0xb0 [megaraid_sas] [ 240.960144] [<ffffffff8108aa50>] ? add_wait_queue+0x60/0x60 [ 240.960154] [<ffffffffa000a6c9>] megasas_get_seq_num+0xd9/0x260 [megaraid_sas] [ 240.960164] [<ffffffffa000ab31>] megasas_start_aen+0x31/0x60 [megaraid_sas] [ 240.960174] [<ffffffffa00136f1>] megasas_probe_one+0x69a/0x81c [megaraid_sas] [ 240.960182] [<ffffffff813345bc>] local_pci_probe+0x5c/0xd0 [ 240.960189] [<ffffffff81335e89>] __pci_device_probe+0xf9/0x100 [ 240.960197] [<ffffffff8130ce6a>] ? kobject_get+0x1a/0x30 [ 240.960205] [<ffffffff81335eca>] pci_device_probe+0x3a/0x60 [ 240.960212] [<ffffffff813f5278>] really_probe+0x68/0x190 [ 240.960217] [<ffffffff813f5505>] driver_probe_device+0x45/0x70 [ 240.960223] [<ffffffff813f55db>] __driver_attach+0xab/0xb0 [ 240.960227] [<ffffffff813f5530>] ? driver_probe_device+0x70/0x70 [ 240.960233] [<ffffffff813f5530>] ? driver_probe_device+0x70/0x70 [ 240.960237] [<ffffffff813f436c>] bus_for_each_dev+0x5c/0x90 [ 240.960243] [<ffffffff813f503e>] driver_attach+0x1e/0x20 [ 240.960248] [<ffffffff813f4c90>] bus_add_driver+0x1a0/0x270 [ 240.960255] [<ffffffffa001e000>] ? 0xffffffffa001dfff [ 240.960260] [<ffffffff813f5b46>] driver_register+0x76/0x140 [ 240.960266] [<ffffffffa001e000>] ? 0xffffffffa001dfff [ 240.960271] [<ffffffff81335b66>] __pci_register_driver+0x56/0xd0 [ 240.960277] [<ffffffffa001e000>] ? 0xffffffffa001dfff [ 240.960286] [<ffffffffa001e09e>] megasas_init+0x9e/0x1000 [megaraid_sas] [ 240.960294] [<ffffffff81002040>] do_one_initcall+0x40/0x180 [ 240.960301] [<ffffffff810a82fe>] sys_init_module+0xbe/0x230 [ 240.960307] [<ffffffff81661ec2>] system_call_fastpath+0x16/0x1b [ 240.960314] INFO: task scsi_scan_7:349 blocked for more than 120 seconds.

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• Big Data – Basics of Big Data Analytics – Day 18 of 21

  - by Pinal Dave

  In yesterday’s blog post we learned the importance of the various components in Big Data Story. In this article we will understand what are the various analytics tasks we try to achieve with the Big Data and the list of the important tools in Big Data Story. When you have plenty of the data around you what is the first thing which comes to your mind? “What do all these data means?” Exactly – the same thought comes to my mind as well. I always wanted to know what all the data means and what meaningful information I can receive out of it. Most of the Big Data projects are built to retrieve various intelligence all this data contains within it. Let us take example of Facebook. When I look at my friends list of Facebook, I always want to ask many questions such as - On which date my maximum friends have a birthday? What is the most favorite film of my most of the friends so I can talk about it and engage them? What is the most liked placed to travel my friends? Which is the most disliked cousin for my friends in India and USA so when they travel, I do not take them there. There are many more questions I can think of. This illustrates that how important it is to have analysis of Big Data. Here are few of the kind of analysis listed which you can use with Big Data. Slicing and Dicing: This means breaking down your data into smaller set and understanding them one set at a time. This also helps to present various information in a variety of different user digestible ways. For example if you have data related to movies, you can use different slide and dice data in various formats like actors, movie length etc. Real Time Monitoring: This is very crucial in social media when there are any events happening and you wanted to measure the impact at the time when the event is happening. For example, if you are using twitter when there is a football match, you can watch what fans are talking about football match on twitter when the event is happening. Anomaly Predication and Modeling: If the business is running normal it is alright but if there are signs of trouble, everyone wants to know them early on the hand. Big Data analysis of various patterns can be very much helpful to predict future. Though it may not be always accurate but certain hints and signals can be very helpful. For example, lots of data can help conclude that if there is lots of rain it can increase the sell of umbrella. Text and Unstructured Data Analysis: unstructured data are now getting norm in the new world and they are a big part of the Big Data revolution. It is very important that we Extract, Transform and Load the unstructured data and make meaningful data out of it. For example, analysis of lots of images, one can predict that people like to use certain colors in certain months in their cloths. Big Data Analytics Solutions There are many different Big Data Analystics Solutions out in the market. It is impossible to list all of them so I will list a few of them over here. Tableau – This has to be one of the most popular visualization tools out in the big data market. SAS – A high performance analytics and infrastructure company IBM and Oracle – They have a range of tools for Big Data Analysis Tomorrow In tomorrow’s blog post we will discuss about very important components of the Big Data Ecosystem – Data Scientist. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Big Data, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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