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  • Is it better for class data to be passed internally or accessed directly?

    - by AaronSzy
    Example: // access fields directly private void doThis() { return doSomeWork(this.data); } // receive data as an argument private void doThis(data) { return doSomeWork(data); } The first option is coupled to the value in this.data while the second option avoids this coupling. I feel like the second option is always better. It promotes loose coupling WITHIN the class. Accessing global class data willy-nilly throughout just seems like a bad idea. Obviously this class data needs to be accessed directly at some point. However, if accesses, to this global class data can be eliminated by parameter passing, it seems that this is always preferable. The second example has the advantage of working with any data of the proper type, whereas the first is bound to working with the just class data. Even if you don't NEED the additional flexibility, it seems nice to leave it as an option. I just don't see any advantage in accessing member data directly from private methods as in the first example. Whats the best practice here? I've referenced code complete, but was not able to find anything on this particular issue.

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  • Implementing a Version check between an Abstract class and it's implementation

    - by Michael Stum
    I have this abstract class and concrete implementation (they are in different assemblies): public abstract class MyAbstractClass { private static readonly int MyAbstractClassVersion = 1; public abstract int ImplementedVersion { get; } protected MyAbstractClass() { CheckVersion(); } private void CheckVersion() { var message = string.Format( "MyAbstractClass implements Version {0}, concrete is Version {1}", RepositoryVersion, ImplementedVersion); if (!MyAbstractClassVersion.Equals(ImplementedVersion)) throw new InvalidOperationException(message); } } public class ConcreteClass : MyAbstractClass { public ConcreteClass() : base() { // ConcreteClass is guaranteed to have // a constructor that calls the base constructor // I just simplified the example } public override int ImplementedVersion { get { return 2; } } } As you see, I call CheckVersion() from the abstract constructor, to get rid of the "virtual member call in base constructor" message, but I am not sure if that's really the way to do it. Sure, it works, but that doesn't mean it will always work, will it? Also, I wonder if I can get the name of the Concrete Type from the CheckVersion() function? I know that adding new abstract members will force an error anyway (System.TypeLoadException) and I'm not sure if I want this type of strict Versioning, but I'm just curious how it would be done properly given only the abstract class and an implementation (I know I could do it by using interfaces and/or a Factory pattern).

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  • In Python, how to make data members visible to subclasses if not known when initializing an object ?

    - by LB
    The title is a bit long, but it should be pretty straightforward for someone well-aware of python. I'm a python newbie. So, maybe i'm doing things in the wrong way. Suppose I have a class TreeNode class TreeNode(Node): def __init__(self, name, id): Node.__init__(self, name, id) self.children = [] and a subclass with a weight: class WeightedNode(TreeNode): def __init__(self,name, id): TreeNode.__init__(self, name, id) self.weight = 0 So far, i think I'm ok. Now, I want to add an object variable called father in TreeNode so that WeightedNode has also this member. The problem is that I don't know when initializing the object who is going to be the father. I set the father afterwards with this method in TreeNode : def set_father(self, father_node): self.father = father_node The problem is then when i'm trying to access self.father in Weighted: print 'Name %s Father %s '%(self.name, self.father.name) I obtain: AttributeError: WeightedNode instance has no attribute 'father' I thought that I could make father visible by doing something in TreeNode.__init__ but i wasn't able to find what. How can i do that ? Thanks.

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  • C++/Qt - Memory allocation question

    - by HardCoder1986
    Hello! I recently started investigating Qt for myself and have the following question: Suppose I have some QTreeWidget* widget. At some moment I want to add some items to it and this is done via the following call: QList<QTreeWidgetItem*> items; // Prepare the items QTreeWidgetItem* item1 = new QTreeWidgetItem(...); QTreeWidgetItem* item2 = new QTreeWidgetItem(...); items.append(item1); items.append(item2); widget->addTopLevelItems(items); So far it looks ok, but I don't actually understand who should control the objects' lifetime. I should explain this with an example: Let's say, another function calls widget->clear();. I don't know what happens beneath this call but I do think that memory allocated for item1 and item2 doesn't get disposed here, because their ownage wasn't actually transfered. And, bang, we have a memory leak. The question is the following - does Qt have something to offer for this kind of situation? I could use boost::shared_ptr or any other smart pointer and write something like shared_ptr<QTreeWidgetItem> ptr(new QTreeWidgetItem(...)); items.append(ptr.get()); but I don't know if the Qt itself would try to make explicit delete calls on my pointers (which would be disastrous since I state them as shared_ptr-managed). How would you solve this problem? Maybe everything is evident and I miss something really simple?

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  • can I store an id value in array of float type ?

    - by srikanth rongali
    I used, for(id value in values) to get the value from an NSArray. Now I want to store it in 2 dimensional float array[][]. When I try to assign the values to array it is giving error:incompatible types in assignment. I tried to cast the value but I got error: pointer value used where a floating point value was expected. I need to store the values in an 2 dimensional array . How can I make it ? Thank You. @implementation fromFileRead1 NSString *fileNameString; int numberOfEnemies, numberOfValues; -(id)init { if( (self = [super init]) ) { NSString *path = @"/Users/sridhar/Desktop/Projects/exampleOnFile2/enemyDetals.txt"; NSString *contentsOfFile = [[NSString alloc] initWithContentsOfFile:path]; NSArray *lines = [contentsOfFile componentsSeparatedByString:@"\n"]; numberOfEnemies = [lines count]; NSLog(@"The number of Lines: %d", numberOfEnemies); for (id line in lines) { NSLog(@"Line %@", line ); NSString *string1 = line; NSArray *split1 = [string1 componentsSeparatedByString:@","]; numberOfValues = [split1 count]; NSLog(@"The number of values in Row: %d", numberOfValues); for (id value in split1) { NSLog(@"value %@", value); float value1; value1 = [split1 objectAtIndex:2]); NSLog(@"VAlue of Value1 at index 2: %f", value1 ); } } } return self; } @end In enemyDetal.txt I have 1,3,3 2,3,2.8 10,2,1.6

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  • How can you pass an object from the form_for helper to a method?

    - by Alex
    So let's say I have a form which is being sent somewhere strange (and by strange we mean, NOT the default route: <% form_for @form_object, :url => {:controller => 'application', :action => 'form_action_thing'} do |f| %> <%= f.text_field :email %> <%= submit_tag 'Login' %> <% end %> Now let's say that we have the method that accepts it. def form_action_thing User.find(????? :email ?????) end My questions are thus: How does can I make the object @form_object available to the receiving method (in this case, form_action_tag)? I've tried params[:form_object], and I've scoured this site and the API, which I have to post below because SO doesn't believe I'm not a spammer (I'm a new member), as well as Googled as many permutations of this idea as I could think of. Nothing. Sorry if I missed something, i'm really trying. How do I address the object, once I've made it accessible to the method? Not params[:form_object], I'm guessing.

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  • Events + Adapter Pattern

    - by Stretto
    I have an adapter pattern on a generic class that essentially adapts between types: class A<T> { event EventHandler e; } class Aadapter<T1, T2> : A<T1> { A<T2> a; Aadapter(A<T2> _a) { a = _a; } } The problem is that A contains an event. I effectively want all event handlers assigned to Adapter to fall through to a. It would be awesome if I could assign the a's event handler to adapter's event handler but this is impossible? The idea here is that A is almost really just A but we need a way to adapt the them. Because of the way event's work I can't how to efficiently do it except manually add two event handlers and when they are called they "relay" the to the other event. This isn't pretty though and it would seem much nicer if I could have something like class A<T> { event EventHandler e; } class Aadapter<T1, T2> : A<T1> { event *e; A<T2> a; Aadapter(A<T2> _a) { a = _a; e = a.e; } } in a sense we have a pointer to the event that we can assign a2's event to. I doubt there is any simple way but maybe someone has some idea to make it work. (BTW, I realize this is possible with virtual events but I'd like to avoid this if at all possible)

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  • [C++] Trouble declaring and recognizing global functions

    - by Sarah
    I've created some mathematical functions that will be used in main() and by member functions in multiple host classes. I was thinking it would be easiest to make these math functions global in scope, but I'm not sure how to do this. I've currently put all the functions in a file called Rdraws.cpp, with the prototypes in Rdraws.h. Even with all the #includes and externs, I'm getting a "symbol not found" error at the first function call in main(). Here's what I have: // Rdraws.cpp #include <cstdlib> using namespace std; #include <cmath> #include "Rdraws.h" #include "rng.h" extern RNG rgen // this is the PRNG used in the simulation; global scope void rmultinom( double p_trans[], int numTrials, int numTrans, int numEachTrans[] ) { // function 1 def } void rmultinom( const double p_trans[], const int numTrials, int numTrans, int numEachTrans[]) { // function 2 def } int rbinom( int nTrials, double pLeaving ) { // function 3 def } // Rdraws.h #ifndef RDRAWS #define RDRAWS void rmultinom( double[], int, int, int[] ); void rmultinom( const double[], const int, int, int[] ); int rbinom( int, double ); #endif // main.cpp ... #include "Rdraws.h" ... extern void rmultinom(double p_trans[], int numTrials, int numTrans, int numEachTrans[]); extern void rmultinom(const double p_trans[], const int numTrials, int numTrans, int numEachTrans[]); extern int rbinom( int n, double p ); ... int main() { ... } I'm pretty new to programming. If there's a dramatically smarter way to do this, I'd love to know.

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  • C++ template and pointers

    - by Kary
    I have a problem with a template and pointers ( I think ). Below is the part of my code: /* ItemCollection.h */ #ifndef ITEMCOLLECTION_H #define ITEMCOLLECTION_H #include <cstddef> using namespace std; template <class T> class ItemCollection { public: // constructor //destructor void insertItem( const T ); private: struct Item { T price; Item* left; Item* right; }; Item* root; Item* insert( T, Item* ); }; #endif And the file with function defintion: /* ItemCollectionTemp.h-member functions defintion */ #include <iostream> #include <cstddef> #include "ItemCollection.h" template <class Type> Item* ItemCollection <T>::insert( T p, Item* ptr) { // function body } Here are the errors which are generated by this line of code: Item* ItemCollection <T>::insert( T p, Item* ptr) Errors: error C2143: syntax error : missing ';' before '*' error C4430: missing type specifier - int assumed. Note: C++ does not support default-int error C2065: 'Type' : undeclared identifier error C2065: 'Type' : undeclared identifier error C2146: syntax error : missing ')' before identifier 'p' error C4430: missing type specifier - int assumed. Note: C++ does not support default-int error C2470: 'ItemCollection::insert' : looks like a function definition, but there is no parameter list; skipping apparent body error C2072: 'ItemCollection::insert': initialization of a function error C2059: syntax error : ')' Any help is much appreciated.

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  • OS-independent Inter-program communication between Python and C

    - by Gyppo
    I have very little idea what I'm doing here, I've never done anything like this before, but a friend and I are writing competing chess programs and they need to be able to communicate to each other. He'll be writing mainly in C, the bulk of mine will be in Python, and I can see a few options: Alternately write to a temp file, or successive temp files. As the communication won't be in any way bulky this could work, but seems like an ugly work-around to me, the programs will have to keep checking for change/new files, it just seems ugly. Find some way of manipulating pipes i.e. mine.py| ./his . This seems like a bit of a dead end. Use sockets. But I don't know what I'd be doing, so could someone give me a pointer to some reading material? I'm not sure if there are OS-independent, language independent methods. Would there have to be some kind of supervisor server program to administrate? Use some kind of HTML protocol, which seems like overkill. I don't mind the programs having to run on the same machine. What do people recommend, and where can I start reading?

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  • Does implementing a Java class under an open-source library's package name constitutes a modificatio

    - by Minyu
    Greetings, I understand that this is not the best forum for getting legal advices. But I am still wondering if anybody has some experience around this topic, or can point me to relevant resources that explain it. I have tried to search it online but could not find clear answers. Assuming I am using a Java open-source library from "somecompany", specifically its entities in the "org.somecompany.somepackage". During development, I found that I need to access some of the internals of that package that are not exposed through its public interface. So I thought maybe creating my own classes under the same "org.somecompany.somepackage" name would make that easier. My question is: does this constitutes a modification of the open-source library? The fully qualified name of my classes look like "org.somecompany.somepackage.myclass". It does seem an "extension" of the original library, even though I am not modifying the original library source or binary. I am also not adding my classes to the open-source jar files. Any advice or pointer to resources will be appreciated!

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  • C++, inject additional data in a method

    - by justik
    I am adding the new modul in some large library. All methods here are implemented as static. Let mi briefly describe the simplified model: typedef std::vector<double> TData; double test ( const TData &arg ) { return arg ( 0 ) * sin ( arg ( 1 ) + ...;} double ( * p_test ) ( const TData> &arg) = &test; class A { public: static T f1 (TData &input) { .... //some computations B::f2 (p_test); } }; Inside f1() some computations are perfomed and a static method B::f2 is called. The f2 method is implemented by another author and represents some simulation algorithm (example here is siplified). class B { public: static double f2 (double ( * p_test ) ( const TData &arg ) ) { //difficult algorithm working p_test many times double res = p_test(arg); } }; The f2 method has a pointer to some weight function (here p_test). But in my case some additional parameters computed in f1 for test() methods are required double test ( const TData &arg, const TData &arg2, char *arg3.... ) { } How to inject these parameters into test() (and so to f2) to avoid changing the source code of the f2 methods (that is not trivial), redesign of the library and without dirty hacks :-) ? The most simple step is to override f2 static double f2 (double ( * p_test ) ( const TData &arg ), const TData &arg2, char *arg3.... ) But what to do later? Consider, that methods are static, so there will be problems with objects. Thanks for your help.

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  • [jQuery] How to load vtip tooltip on a dynamically generated element?

    - by adaneko
    I'm new to jQuery and trying to combine the use of a tooltip plugin and a lightbox plugin. More specifically, I am using Colorbox (http://colorpowered.com/colorbox/) and vtip. Colorbox generates a div which displays an image like this: <div id="cboxLoadedContent" style="display: block; width: 400px; overflow: auto; height: 498px;"> <img src="image.jpg" id="cboxPhoto" style="margin: 49px auto auto; border: medium none; display: block; float: none; cursor: pointer;"> </div> I next add class="vtip" title="This is a tip." in order to use the vtip style, but for some reason it does not work when it's a title tag on an element dynamically generated by Colorbox, but works on anything already loaded on the page. Can anyone explain to me why this is and possibly offer some solutions to fix this problem?

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  • What do I need to do if I want all typeof(MyEnum)'s to be handled with MyEnumModelBinder?

    - by Byron Sommardahl
    I have an Enum that appears in several of my models. For the most part, the DefaultModelBinder handles binding to my models beautifully. That it, until it gets to my Enum... it always returns the first member in the Enum no matter what is handed it by the POST. My googling leads me to believe I need to have a model binder that knows how to handle Enums. I found an excellent article on a possible custom modelBinder for Enums: http://eliasbland.wordpress.com/2009/08/08/enumeration-model-binder-for-asp-net-mvc/. I've since implemented that modelBinder and registered it in my global.asax: ModelBinders.Binders[typeof (MyEnum)] = new EnumBinder<MyEnum>(MyEnum.MyDefault); For some reason, the EnumBinder< isn't being called when the model I'm binding to has MyEnum. I have a breakpoint in the .BindModel() method and it never break. Also, my model hasn't changed after modelBinding. Have I done everything? What am I missing here?

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  • How can I hide this overlay element intelligently?

    - by inkedmn
    The site I'm working on has a collection of navigation elements across the top ("Products", "Company", etc.). When you mouse over the Products link, an overlay appears that shows a list of products with links to each. There's a small link at the top of the container that, when clicked, closes the container. All of this works as advertised. The client has asked that, once a user's mouse pointer is a sufficient distance from the overlay element, the overlay element would close (without them having to click the 'close' link). This element appears on multiple pages that have disparate content, so I'm afraid it won't be as simple as adding a mouseover listener to another single element within the page and have it work everywhere. My question, I suppose, is this: is there a relatively easy way to know when the mouse cursor is x pixels away from this container and trigger an event when this occurs? My other thought is that I could just find several elements on the page that fit this criteria and add mouseover listeners to each, but I'm assuming there's a more elegant way of handling this. Thanks in advance - and please let me know if more detail is needed.

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  • Dealloc'd Predicate crashing iPhone App!

    - by DVG
    To preface, this is a follow up to an inquiry made a few days ago: http://stackoverflow.com/questions/2981803/iphone-app-crashes-when-merging-managed-object-contexts Short Version: EXC_BAD_ACCESS is crashing my app, and zombie-mode revealed the culprit to be my predicate embedded within the fetch request embedded in my Fetched Results Controller. How does an object within an object get released without an explicit command to do so? Long Version: Application Structure Platforms View Controller - Games View Controller (Predicated upon platform selection) - Add Game View Controller When a row gets clicked on the Platforms view, it sets an instance variable in Games View for that platform, then the Games Fetched Results Controller builds a fetch request in the normal way: - (NSFetchedResultsController *)fetchedResultsController{ if (fetchedResultsController != nil) { return fetchedResultsController; } //build the fetch request for Games NSFetchRequest *request = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Game" inManagedObjectContext:context]; [request setEntity:entity]; //predicate NSPredicate *predicate = [NSPredicate predicateWithFormat:@"platform == %@", selectedPlatform]; [request setPredicate:predicate]; //sort based on name NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil]; [request setSortDescriptors:sortDescriptors]; //fetch and build fetched results controller NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:request managedObjectContext:context sectionNameKeyPath:nil cacheName:@"Root"]; aFetchedResultsController.delegate = self; self.fetchedResultsController = aFetchedResultsController; [sortDescriptor release]; [sortDescriptors release]; [predicate release]; [request release]; [aFetchedResultsController release]; return fetchedResultsController; } At the end of this method, the fetchedResultsController's _fetch_request - _predicate member is set to an NSComparisonPredicate object. All is well in the world. By the time - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section gets called, the _predicate is now a Zombie, which will eventually crash the application when the table attempts to update itself. I'm more or less flummoxed. I'm not releasing the fetched results controller or any of it's parts, and the only part getting dealloc'd is the predicate. Any ideas?

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  • Interpretation of int (*a)[3]

    - by kapuzineralex
    When working with arrays and pointers in C, one quickly discovers that they are by no means equivalent although it might seem so at a first glance. I know about the differences in L-values and R-values. Still, recently I tried to find out the type of a pointer that I could use in conjunction with a two-dimensional array, i.e. int foo[2][3]; int (*a)[3] = foo; However, I just can't find out how the compiler "understands" the type definition of a in spite of the regular operator precedence rules for * and []. If instead I were to use a typedef, the problem becomes significantly simpler: int foo[2][3]; typedef int my_t[3]; my_t *a = foo; At the bottom line, can someone answer me the questions as to how the term int (*a)[3] is read by the compiler? int a[3] is simple, int *a[3] is simple as well. But then, why is it not int *(a[3])? EDIT: Of course, instead of "typecast" I meant "typedef" (it was just a typo).

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  • mutableCopyWithZone updating a property value.

    - by Jim
    I have a Class that I need to copy with the ability to make changes the value of a variable on both Classes. Simply put the classes need to remain clones of each other at all times. My understanding of the documentation is that I can do this using a shallow copy of the Class which has also been declared mutable. By shallow copying the pointer value for the variable will be cloned so that it is an exact match in both classes. So when I update the variable in the original the copy will be updated simultaneously. Is this right? As you can see below I have used mutableCopyWithZone in the class I want to copy. I have tried both NSCopyObject and allocWithZone methods to get this to work. Although I'm able to copy the class and it appears as intended, when updating the variable it is not changing value in the copied Class. - (id)mutableCopyWithZone:(NSZone *)zone { //ReviewViewer *copy = NSCopyObject(self, 0, zone); ReviewViewer *copy = [[[self class] allocWithZone:zone] init]; copy->infoTextViews = [infoTextViews copy]; return copy; } infoTextViews is a property declared as nonatomic, retain in the header file of the class being copied. I have also implemented the NSMutableCopying protocol accordingly. Any help would be great.

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  • Is there any seriously good reason why a view can not completely manage itself?

    - by mystify
    Example: I have an warning triangle icon, which is a UIImageView subclass. That warning is blended in with an animation, pulses for 3 seconds and then fades out. it always has a parent view! it's always only used this way: alloc, init, add as subview, kick off animation, when done:remove from superview So I want this: [WarningIcon warningAtPosition:CGPointMake(50.0f, 100.0f) parentView:self]; BANG! That's it. Call and forget. The view adds itself as subview to the parent, then does it's animations. And when done, it cuts itself off from the branch with [self removeFromSupeview];. Now some nerd a year ago told me: "Never cut yourself off from your own branch". In other words: A view should never ever remove itself from superview if it's no more referenced anywhere. I want to get it, really. WHY? Think about this: The hard way, I would do actually the exact same thing. Create an instance and hang me in as delegate, kick off the animation, and when the warning icon is done animating, it calls me back "hey man i'm done, get rid of me!" - so my delegate method is called with an pointer to that instance, and I do the exact same thing: [thatWarningIcon removeFromSuperview]; - BANG. Now I'd really love to know why this sucks. Life would be so easy.

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  • is there any way to terminate UIImagePickerViewController while taking video?

    - by wadelim
    Hello! It's the first time to ask a question! until now, I don't need to ask qestion about my problem because Here is the rellay good place to share and solve my programming error(problem?)! now, I'm having a big problem at UIImagePickerViewController Fisrt, while My app is enconding Video Image on pckerViewcontroller, If I push the home button to go background, My app is terminated T_T(EXC_BAD_ACCESS) I want to keep my app alive(living) or close safely pickerview controller to be back I'm going crazy if there is anyone to help me, I would really appreciated Thank you! // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *// // in Init Method [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(enterBackgound:) name:UIApplicationDidEnterBackgroundNotification object:nil]; // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *// UIImagePickerController *pickerController = [UIImagePickerController new]; i_pc = pickerController; // "i_pc" is member instance .... [self presentModalViewController:pickerController animated:YES]; [pickerController release]; // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *// while encoding some video in pckerview Contrller, Push homeButton! and return back then my app is killed // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *// // this is my code to try to solve above problem.. But It's not working -(void)enterBackground:(NSNotification *)notification{ [self dismissModalViewControllerAnimated:YES]; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *//

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  • Convert C# (with typed events) to VB.NET

    - by Steven
    I have an ASPX page (with VB Codebehind). I would like to extend the GridView class to show the header / footer when no rows are returned. I found a C# example online (link) (source). However, I cannot convert it to VB because it uses typed events (which are not legal in VB). I have tried several free C# to VB.NET converters online, but none have worked. Please convert the example to VB.NET or provide an alternate method of extending the GridView class. Notes / Difficulties: If you get an error with DataView objects, specify the type as System.Data.DataView and the type comparison could be the following: If data.[GetType]() Is GetType(System.Data.DataView) Then Since the event MustAddARow cannot have a type in VB (and RaiseEvent event doesn't have a return value), how can I compare it to Nothing in the function OnMustAddARow()? EDIT: The following is a sample with (hopefully) relevant code to help answer the question. namespace AlwaysShowHeaderFooter { public delegate IEnumerable MustAddARowHandler(IEnumerable data); public class GridViewAlwaysShow : GridView { ////////////////////////////////////// // Various member functions omitted // ////////////////////////////////////// protected IEnumerable OnMustAddARow(IEnumerable data) { if (MustAddARow == null) { throw new NullReferenceException("The datasource has no rows. You must handle the \"MustAddARow\" Event."); } return MustAddARow(data); } public event MustAddARowHandler MustAddARow; } }

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  • explain notifier.c from the Linux kernel

    - by apollon
    I'm seeking to fully understand the following code snippet from kernel/notifier.c. I have read and built simple link lists and think I get the construct from K&R's C programming. The second line below which begins with the 'int' appears to be two items together which is unclear. The first is the (*notifier_call) which I believe has independent but related significance with the second containing a 'notifier block' term. Can you explain how it works in detail? I understand that there is a function pointer and multiple subscribers possible. But I lack the way to tie these facts together, and could use a primer or key so I exactly understand how the code works. The third line looks to contain the linking structure, or recursive nature. Forgive my terms, and correct them as fit as I am a new student of computer science terminology. struct notifier_block { int (*notifier_call)(struct notifier_block *, unsigned long, void *); struct notifier_block *next; int priority; };

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  • How to store <TR> id value in array, when I toggle?

    - by James123
    I am toggling 'tr.subCategory1'and its siblings .RegText. at the same time I am trying to store its ids in the array like this list_Visible_Ids[$(this).attr('id')] = $(this).css('display') != 'none' ? 1 : null; (When I collapsed I need store 'null' in array at its id place, If I expand I need store I need store 1 at its id place). But everytime alert($(this).css('display')) showing block. How can I handle this?. So When I collapsed or expanded it is storing 1 only. $(document).ready(function() { $('tr[@class^=RegText]').hide().children('td'); list_Visible_Ids = []; var idsString, idsArray; idsString = $('#myVisibleRows').val(); idsArray = idsString.split(','); $.each(idsArray, function() { if (this != "" || this != null) { $('#' + this).siblings('.RegText').toggle(); list_Visible_Ids[this] = 1; } }); $('tr.subCategory1') .css("cursor", "pointer") .attr("title", "Click to expand/collapse") .click(function() { $(this).siblings('.RegText').toggle(); $(this).siblings('.VolumeRegText').toggle(); //alert($(this).css('display')) list_Visible_Ids[$(this).attr('id')] = $(this).css('display') != 'none' ? 1 : null; }); $('#form1').submit(function() { idsString = ''; for (var index in list_Visible_Ids) { idsString += (idsString != '' ? ',' : '') + index; } $('#myVisibleRows').val(idsString); form1.submit(); }); });

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  • JMS message. Model to include data or pointers to data?

    - by John
    I am trying to resolve a design difference of opinion where neither of us has experience with JMS. We want to use JMS to communicate between a j2ee application and the stand-alone application when a new event occurs. We would be using a single point-to-point queue. Both sides are Java-based. The question is whether to send the event data itself in the JMS message body or to send a pointer to the data so that the stand-alone program can retrieve it. Details below. I have a j2ee application that supports data entry of new and updated persons and related events. The person records and associated events are written to an Oracle database. There are also stand-alone, separate programs that contribute new person and event records to the database. When a new event occurs through any of 5-10 different application functions, I need to notify remote systems through an outbound interface using an industry-specific standard messaging protocol. The outbound interface has been designed as a stand-alone application to support scalability through asynchronous operation and by moving it to a separate server. The j2ee application currently has most of the data in memory at the time the event is entered. The data would consist of approximately 6 different objects; a person object and some with multiple instances for an average size in the range of 3000 to 20,000 bytes. Some special cases could be many times this amount. From a performance and reliability perspective, should I model the JMS message to pass all the data needed to create the interface message, or model the JMS message to contain record keys for the data and have the stand-alone Java application retrieve the data to create the interface message?

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  • Delete on a very deep tree

    - by Kathoz
    I am building a suffix trie (unfortunately, no time to properly implement a suffix tree) for a 10 character set. The strings I wish to parse are going to be rather long (up to 1M characters). The tree is constructed without any problems, however, I run into some when I try to free the memory after being done with it. In particularly, if I set up my constructor and destructor to be as such (where CNode.child is a pointer to an array of 10 pointers to other CNodes, and count is a simple unsigned int): CNode::CNode(){ count = 0; child = new CNode* [10]; memset(child, 0, sizeof(CNode*) * 10); } CNode::~CNode(){ for (int i=0; i<10; i++) delete child[i]; } I get a stack overflow when trying to delete the root node. I might be wrong, but I am fairly certain that this is due to too many destructor calls (each destructor calls up to 10 other destructors). I know this is suboptimal both space, and time-wise, however, this is supposed to be a quick-and-dirty solution to a the repeated substring problem. tl;dr: how would one go about freeing the memory occupied by a very deep tree? Thank you for your time.

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