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  • Passing Objects between different files

    - by user309779
    Typically, if I want to pass an object to an instance of something I would do it like so... Listing 1 File 1: public class SomeClass { // Some Properties public SomeClass() { public int ID { get { return mID; } set { mID = value; } } public string Name { set { mName = value; } get { return mName; } } } } public class SomeOtherClass { // Method 1 private void Method1(int one, int two) { SomeClass USER; // Create an instance Squid RsP = new Squid(); RsP.sqdReadUserConf(USER); // Able to pass 'USER' to class method in different file. } } In this example, I was not able to use the above approach. Probably because the above example passes an object between classes. Whereas, below, things are defined in a single class. I had to use some extra steps (trial & error) to get things to work. I am not sure what I did here or what its called. Is it good programming practice? Or is there is an easier way to do this (like above). Listing 2 File 1: private void SomeClass1 { [snip] TCOpt_fM.AutoUpdate = optAutoUpdate.Checked; TCOpt_fM.WhiteList = optWhiteList.Checked; TCOpt_fM.BlackList = optBlackList.Checked; [snip] private TCOpt TCOpt_fM; TCOpt_fM.SaveOptions(TCOpt_fM); } File 2: public class TCOpt: { public TCOpt OPTIONS; [snip] private bool mAutoUpdate = true; private bool mWhiteList = true; private bool mBlackList = true; [snip] public bool AutoUpdate { get { return mAutoUpdate; } set { mAutoUpdate = value; } } public bool WhiteList { get { return mWhiteList; } set { mWhiteList = value; } } public bool BlackList { get { return mBlackList; } set { mBlackList = value; } } [snip] public bool SaveOptions(TCOpt OPTIONS) { [snip] Some things being written out to a file here [snip] Squid soSwGP = new Squid(); soSgP.sqdWriteGlobalConf(OPTIONS); } } File 3: public class SomeClass2 { public bool sqdWriteGlobalConf(TCOpt OPTIONS) { Console.WriteLine(OPTIONS.WhiteSites); // Nothing prints here Console.WriteLine(OPTIONS.BlackSites); // Or here } } Thanks in advance, XO

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  • [NEWVERSION]algorithm || method to write prog[UNSOLVED] [closed]

    - by fatai
    I am one of the computer science student. Everyone solve problem with a different or same method, ( but actually I dont know whether they use method or I dont know whether there are such common method to approach problem.) if there are common method, What is it ? If there are different method, which method are you using ? All teacher give us problem which in simple form sometimes, but they donot introduce any approach or method(s) so that we cannot make a decision to choose the method then apply that one to problem , afterward find solution then write code.No help from teacher , push us to find method to solve homework. Ex: my friend is using no method , he says "I start to construct algorithm while I try to write prog." I have found one method when I failed the course, More accurately, my method: When I counter problem in language , I will get more paper and then ; first, input/ output step ; my prog will take this / these there argument(s) and return namely X , ex : in c, input length is not known and at same type , so I must use pointer desired output is in form of package , so use structure second, execution part ; in that step , I am writing all step which are goes to final output ex : in python ; 1.) [ + , [- , 4 , [ * , 1 , 2 ]], 5] 2.) [ + , [- , 4 , 2 ],5 ] 3.) [ + , 2 , 5] 4.) 7 ==> return 7 third, I will write test code ex : in c++ input : append 3 4 5 6 vector_x remove 0 1 desired output vector_x holds : 5 6 now, my other question is ; What is/are other method(s) which have/has been; used to construct class :::: for c++ , python, java used to communicate classes / computers used for solving embedded system problem ::::: for c by other user? Some programmer uses generalized method without considering prog-language(java , perl .. ), what is this method ? Why I wonder , because I learn if you dont costruct algorithm on paper, you may achieve your goal. Like no money no lunch , I can say no algorithm no prog therefore , feel free when you write your own method , a way which is introduced by someone else but you are using and you find it is so efficient

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  • Isn't the C++ standard library backward-compatible?

    - by Chris Metzler
    Hi. I'm working on a 64-bit Linux system, trying to build some code that depends on third-party libraries for which I have binaries. During linking, I get a stream of undefined reference errors for one of the libraries, indicating that the linker couldn't resolve references to standard C++ functions/classes, e.g.: librxio.a(EphReader.o): In function `gpstk::EphReader::read_fic_data(std::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)': EphReader.cpp:(.text+0x27c): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::__ostream_insert<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*, long)' EphReader.cpp:(.text+0x4e8): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::__ostream_insert<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*, long)' I'm not really a C++ programmer, but this looks to me like it can't find the standard library. Doing some more research, I got the following when I looked at librxio's dependency for the standard library: $ ldd librxio.so.16.0 ./librxio.so.16.0: /usr/lib64/libstdc++.so.6: version `GLIBCXX_3.4.9' not found (required by ./librxio.so.16.0) libm.so.6 => /lib64/libm.so.6 (0x00002aaaaad45000) libstdc++.so.6 => /usr/lib64/libstdc++.so.6 (0x00002aaaaafc8000) libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00002aaaab2c8000) libc.so.6 => /lib64/libc.so.6 (0x00002aaaab4d7000) /lib64/ld-linux-x86-64.so.2 (0x0000555555554000) So I read that as saying that librxio (one of the third-party libraries) requires at least v3.4.9 of the standard library. But the version I have installed is 4.1.2: $ rpm -qa | grep libstdc compat-libstdc++-33-3.2.3-61.x86_64 libstdc++-devel-4.1.2-14.el5.i386 libstdc++-devel-4.1.2-14.el5.x86_64 libstdc++-4.1.2-14.el5.x86_64 libstdc++-4.1.2-14.el5.i386 Shouldn't this work? The shared object major number is 6, same as for v3.4.9. At this level, shouldn't this be backward compatible? It seems like the third-party library is looking for an earlier version of the standard library than what I have installed; but isn't there backward compatibility between versions with the same major number for the shared library? Again, I'm not really a C++ programmer; but I don't see what the problem is. Any advice greatly appreciated. Thanks.

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  • Java.lang.reflext.Proxy returning another proxy from invocation results in ClassCastException on ass

    - by matao
    So I'm playing with geotools and I thought I'd proxy one of their data-access classes and trace how it was being used in their code. I coded up a dynamic proxy and wrapped a FeatureSource (interface) in it and off it went happily. Then I wanted to look at some of the transitive objects returned by the featureSource as well, since the main thing a FeatureSource does is return a FeatureCollection (FeatureSource is analogous to a sql DataSource and featurecollection to an sql statement). in my invocationhandler I just passed the call through to the underlying object, printing out the target class/method/args and result as I went, but for calls that returned a FeatureCollection (another interface), I wrapped that object in my proxy (the same class but a new instance, shouldn't matter should it?) and returned it. BAM! Classcast exception: java.lang.ClassCastException: $Proxy5 cannot be cast to org.geotools.feature.FeatureCollection at $Proxy4.getFeatures(Unknown Source) at MyClass.myTestMethod(MyClass.java:295) the calling code: FeatureSource<SimpleFeatureType, SimpleFeature> featureSource = ... // create the FS featureSource = (FeatureSource<SimpleFeatureType, SimpleFeature>) FeatureSourceProxy.newInstance(featureSource, features); featureSource.getBounds();// ok featureSource.getSupportedHints();// ok DefaultQuery query1 = new DefaultQuery(DefaultQuery.ALL); FeatureCollection<SimpleFeatureType, SimpleFeature> results = featureSource.getFeatures(query1); //<- explosion here the Proxy: public class FeatureSourceProxy implements java.lang.reflect.InvocationHandler { private Object target; private List<SimpleFeature> features; public static Object newInstance(Object obj, List<SimpleFeature> features) { return java.lang.reflect.Proxy.newProxyInstance( obj.getClass().getClassLoader(), obj.getClass().getInterfaces(), new FeatureSourceProxy(obj, features) ); } private FeatureSourceProxy(Object obj, List<SimpleFeature> features) { this.target = obj; this.features = features; } public Object invoke(Object proxy, Method m, Object[] args)throws Throwable{ Object result = null; try { if("getFeatures".equals(m.getName())){ result = interceptGetFeatures(m, args); } else{ result = m.invoke(target, args); } } catch (Exception e) { throw new RuntimeException("unexpected invocation exception: " + e.getMessage(), e); } return result; } private Object interceptGetFeatures(Method m, Object[] args) throws Exception{ return newInstance(m.invoke(target, args), features); } } Is it possible to dynamically return proxies of interfaces from a proxied interface or am I doing something wrong? cheers!

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  • How to load a springframework ApplicationContext from Jython

    - by staticman
    I have a class that loads a springframework application context like so: package com.offlinesupport; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class OfflineScriptSupport { private static ApplicationContext appCtx; public static final void initialize() { appCtx = new ClassPathXmlApplicationContext( new String[] { "mycontext.spring.xml" } ); } public static final ApplicationContext getApplicationContext() { return appCtx; } public static final void main( String[] args ) { System.out.println( "Starting..." ); initialize(); System.out.println( "loaded" ); } } The class OfflineScriptSupport, and the file mycontext.spring.xml are each deployed into separate jars (along with other classes and resources in their respective modules). Lets say the jar files are OfflineScriptSupport.jar and *MyContext.jar". mycontext.spring.xml is put at the root of the jar. In a Jython script (*myscript.jy"), I try to call the initialize method to create the application context: from com.offlinesupport import OfflineScriptSupport OfflineScriptSupport.initialize(); I execute the Jython script with the following command (from Linux): jython -Dpython.path=spring.jar:OfflineScriptSupport.jar:MyContext.jar myscript.jy The Springframework application context cannot find the mycontext.spring.xml file. It displays the following error: java.io.FileNotFoundException: class path resource [mycontext.spring.xml] cannot be opened because it does not exist at org.springframework.core.io.ClassPathResource.getInputStream(ClassPathResource.java:137) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:167) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:148) at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:126) at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:142) at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:113) at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:81) at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:89) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:269) at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:87) at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:72) at com.offlinesupport.OfflineScriptSupport.initialize(OfflineScriptSupport.java:27) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) If I run the jar directly from Java (using the main entry point in OfflineScriptSupport) it works and there is no error thrown. Is there something special about the way Jython handles classpaths making the Springframework's ClassPathXmlApplicationContext not work (i.e. not be able to find resource files in the classpath)?

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  • Simplest way to flatten document to a view in RavenDB

    - by degorolls
    Given the following classes: public class Lookup { public string Code { get; set; } public string Name { get; set; } } public class DocA { public string Id { get; set; } public string Name { get; set; } public Lookup Currency { get; set; } } public class ViewA // Simply a flattened version of the doc { public string Id { get; set; } public string Name { get; set; } public string CurrencyName { get; set; } // View just gets the name of the currency } I can create an index that allows client to query the view as follows: public class A_View : AbstractIndexCreationTask<DocA, ViewA> { public A_View() { Map = docs => from doc in docs select new ViewA { Id = doc.Id, Name = doc.Name, CurrencyName = doc.Currency.Name }; Reduce = results => from result in results group on new ViewA { Id = result.Id, Name = result.Name, CurrencyName = result.CurrencyName } into g select new ViewA { Id = g.Key.Id, Name = g.Key.Name, CurrencyName = g.Key.CurrencyName }; } } This certainly works and produces the desired result of a view with the data transformed to the structure required at the client application. However, it is unworkably verbose, will be a maintenance nightmare and is probably fairly inefficient with all the redundant object construction. Is there a simpler way of creating an index with the required structure (ViewA) given a collection of documents (DocA)? FURTHER INFORMATION The issue appears to be that in order to have the index hold the data in the transformed structure (ViewA), we have to do a Reduce. It appears that a Reduce must have both a GROUP ON and a SELECT in order to work as expected so the following are not valid: INVALID REDUCE CLAUSE 1: Reduce = results => from result in results group on new ViewA { Id = result.Id, Name = result.Name, CurrencyName = result.CurrencyName } into g select g.Key; This produces: System.InvalidOperationException: Variable initializer select must have a lambda expression with an object create expression Clearly we need to have the 'select new'. INVALID REDUCE CLAUSE 2: Reduce = results => from result in results select new ViewA { Id = result.Id, Name = result.Name, CurrencyName = result.CurrencyName }; This prduces: System.InvalidCastException: Unable to cast object of type 'ICSharpCode.NRefactory.Ast.IdentifierExpression' to type 'ICSharpCode.NRefactory.Ast.InvocationExpression'. Clearly, we also need to have the 'group on new'. Thanks for any assistance you can provide. (Note: removing the type (ViewA) from the constructor calls has no effect on the above)

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  • Overloading framework methods in objective-c, or retaining local changes with framework updates.

    - by Jeff B
    I am using cocos2d to build an iPhone game. It's mostly done, but along the way I came across some things that I would like to handle better. I am fairly new to Objective C, and honestly I do more Perl scripting in my day-to-day job than anything, so my C skills are a little rusty. One of them is the fact that I have modified cocos2d files for some specific cases in my game. However, when I update to a new version, I have to manually pull my changes forward. So, the question is, what is the best way to deal with this? Some options I have thought of: Overload/redefine the cocos2d classes. I was under the impression that I cannot overload existing class functions, so I don't think this will work. Create patches that I re-apply after library updates. I don't think this will work as the new files won't necessarily be the same as the old ones, and if they were, I could just copy the whole file forward. Turn in my changes to Cocos2d. Not an option as my changes are very specific to my application. Am I missing something obvious? UPDATE: I will explain what I am doing to be more clear. Cocos2d has a CCNode object, which can contain children, etc. I added a shadow, which is very similar to a child, but handled a little differently. The shadow has an offset from the parent, and translates with it's parent, rotates around it's own center when the parent rotates, etc. The shadow is not included as a true child, however, so given the correct z-index, the shadows can render under ALL other objects, but still move with the parent. To do this I added addShadow functions to CCNode, and modified the setPosition and setRotate functions to move the shadowSprite: CCNode.m: -(id) init { if ((self=[super init]) ) { ... shadowSprite_ = nil; ... } } ... -(BOOL) addShadow: (CCNode*) child offset: (CGPoint) offset { shadowSprite_ = child; shadowSprite_.position = CGPointMake(position_.x+offset.x, position_.y+offset.y); return YES; } ... -(void) setRotation: (float)newRotation { rotation_ = newRotation; isTransformDirty_ = isInverseDirty_ = YES; if(shadowSprite_) { [shadowSprite_ setRotation: newRotation]; } } There is more, of course, including the prototypes in the .h file, but that is the basics. I don't think I need shadowSprite to be a property, because I don't need to access it after it has been added.

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  • How to redirect to a page using a button tag in html?

    - by Vlad Radulescu
    When I Click a button I want to get redirected to a page. The problem is...if I use the normal sintax , the button works fine, but If I apply some css to id by ussing # and .(classes) ,the button it`s not working any more ?! How can I keep my css and functionality at the same time ?! This is my code: <body> <input id="buttonrain" class="classname" type="button" onClick="window.location.href='rain.html'" value="Rain" /> <!--or <a href="rain.html" id="buttonrain" class="classname">Rain</a> still not working--> </body> CSS FILE html { min-width: 100%; min-height: 100%; } body{ width: 1024px; height:600px; background:white; margin:0px; padding:0px 0px; display:block; overflow:hidden; } .classname { -moz-box-shadow:inset 0px 1px 0px 0px #ffffff; -webkit-box-shadow:inset 0px 1px 0px 0px #ffffff; box-shadow:inset 0px 1px 0px 0px #ffffff; background:-webkit-gradient( linear, left top, left bottom, color-stop(0.05, #f0ea3c), color-stop(1, #dfdfdf) ); background:-moz-linear-gradient( center top, #f0ea3c 5%, #dfdfdf 100% ); filter:progid:DXImageTransform.Microsoft.gradient(startColorstr='#f0ea3c', endColorstr='#dfdfdf'); background-color:#f0ea3c; -moz-border-radius:6px; -webkit-border-radius:6px; border-radius:6px; border:1px solid #dcdcdc; display:inline-block; color:#0f000f; font-family:Verdana; font-size:15px; font-weight:bold; padding:18px 9px; text-decoration:none; text-shadow:1px 1px 0px #ffffff; position:relative; bottom:250px; }.classname:active { position:relative; top:1px; } #buttonrain{ left:80px; }

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  • idiomatic property changed notification in scala?

    - by Jeremy Bell
    I'm trying to find a cleaner alternative (that is idiomatic to Scala) to the kind of thing you see with data-binding in WPF/silverlight data-binding - that is, implementing INotifyPropertyChanged. First, some background: In .Net WPF or silverlight applications, you have the concept of two-way data-binding (that is, binding the value of some element of the UI to a .net property of the DataContext in such a way that changes to the UI element affect the property, and vise versa. One way to enable this is to implement the INotifyPropertyChanged interface in your DataContext. Unfortunately, this introduces a lot of boilerplate code for any property you add to the "ModelView" type. Here is how it might look in Scala: trait IDrawable extends INotifyPropertyChanged { protected var drawOrder : Int = 0 def DrawOrder : Int = drawOrder def DrawOrder_=(value : Int) { if(drawOrder != value) { drawOrder = value OnPropertyChanged("DrawOrder") } } protected var visible : Boolean = true def Visible : Boolean = visible def Visible_=(value: Boolean) = { if(visible != value) { visible = value OnPropertyChanged("Visible") } } def Mutate() : Unit = { if(Visible) { DrawOrder += 1 // Should trigger the PropertyChanged "Event" of INotifyPropertyChanged trait } } } For the sake of space, let's assume the INotifyPropertyChanged type is a trait that manages a list of callbacks of type (AnyRef, String) = Unit, and that OnPropertyChanged is a method that invokes all those callbacks, passing "this" as the AnyRef, and the passed-in String). This would just be an event in C#. You can immediately see the problem: that's a ton of boilerplate code for just two properties. I've always wanted to write something like this instead: trait IDrawable { val Visible = new ObservableProperty[Boolean]('Visible, true) val DrawOrder = new ObservableProperty[Int]('DrawOrder, 0) def Mutate() : Unit = { if(Visible) { DrawOrder += 1 // Should trigger the PropertyChanged "Event" of ObservableProperty class } } } I know that I can easily write it like this, if ObservableProperty[T] has Value/Value_= methods (this is the method I'm using now): trait IDrawable { // on a side note, is there some way to get a Symbol representing the Visible field // on the following line, instead of hard-coding it in the ObservableProperty // constructor? val Visible = new ObservableProperty[Boolean]('Visible, true) val DrawOrder = new ObservableProperty[Int]('DrawOrder, 0) def Mutate() : Unit = { if(Visible.Value) { DrawOrder.Value += 1 } } } // given this implementation of ObservableProperty[T] in my library // note: IEvent, Event, and EventArgs are classes in my library for // handling lists of callbacks - they work similarly to events in C# class PropertyChangedEventArgs(val PropertyName: Symbol) extends EventArgs("") class ObservableProperty[T](val PropertyName: Symbol, private var value: T) { protected val propertyChanged = new Event[PropertyChangedEventArgs] def PropertyChanged: IEvent[PropertyChangedEventArgs] = propertyChanged def Value = value; def Value_=(value: T) { if(this.value != value) { this.value = value propertyChanged(this, new PropertyChangedEventArgs(PropertyName)) } } } But is there any way to implement the first version using implicits or some other feature/idiom of Scala to make ObservableProperty instances function as if they were regular "properties" in scala, without needing to call the Value methods? The only other thing I can think of is something like this, which is more verbose than either of the above two versions, but is still less verbose than the original: trait IDrawable { private val visible = new ObservableProperty[Boolean]('Visible, false) def Visible = visible.Value def Visible_=(value: Boolean): Unit = { visible.Value = value } private val drawOrder = new ObservableProperty[Int]('DrawOrder, 0) def DrawOrder = drawOrder.Value def DrawOrder_=(value: Int): Unit = { drawOrder.Value = value } def Mutate() : Unit = { if(Visible) { DrawOrder += 1 } } }

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  • Adding NavigationControl to a TabBar Application containing UITableViews

    - by kungfuslippers
    Hi, I'm new to iPhone dev and wanted to get advice on the general design pattern / guide for putting a certain kind of app together. I'm trying to build a TabBar type application. One of the tabs needs to display a TableView and selecting a cell from within the table view will do something else - maybe show another table view or a web page. I need a Navigation Bar to be able to take me back from the table view/web page. The approach I've taken so far is to: Create an app based around UITabBarController as the rootcontroller i.e. @interface MyAppDelegate : NSObject <UIApplicationDelegate> { IBOutlet UIWindow *window; IBOutlet UITabBarController *rootController; } Create a load of UIViewController derived classes and associated NIBs and wire everything up in IB so when I run the app I get the basic tabs working. I then take the UIViewController derived class and modify it to the following: @interface MyViewController : UIViewController<UITableViewDataSource, UITableViewDelegate> { } and I add the delegate methods to the implementation of MyViewController - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return 2; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; } if (indexPath.row == 0) { cell.textLabel.text = @"Mummy"; } else { cell.textLabel.text = @"Daddy"; } return cell; } Go back to IB , open MyViewController.xib and drop a UITableView onto it. Set the Files Owner to be MyViewController and then set the delegate and datasource of the UITableView to be MyViewController. If I run the app now, I get the table view appearing with mummy and daddy working nicely. So far so good. The question is how do I go about incorporating a Navigation Bar into my current code for when I implement: - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath() { // get row selected NSUInteger row = [indexPath row]; if (row == 0) { // Show another table } else if (row == 1) { // Show a web view } } Do I drop a NavigationBar UI control onto MyControllerView.xib ? Should I create it programmatically? Should I be using a UINavigationController somewhere ? I've tried dropping a NavigationBar onto my MyControllerView.xib in IB but its not shown when I run the app, only the TableView is displayed.

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  • Comparing Nested object properties using C#

    - by Kumar
    I have a method which compares two objects and returns a list of all the property names which are different. public static IList<string> GetDifferingProperties(object source, object) { var sourceType = source.GetType(); var sourceProperties = sourceType.GetProperties(); var targetType = target.GetType(); var targetProperties = targetType.GetProperties(); var properties = (from s in sourceProperties from t in targetProperties where s.Name == t.Name && s.PropertyType == t.PropertyType && s.GetValue(source,null) != t.GetValue(target,null) select s.Name).ToList(); return properties; } For example if I have two classes as follows: public class Address { public string AddressLine1 { get; set; } public string AddressLine2 { get; set; } public string City { get; set; } public string State { get; set; } public string Zip { get; set; } } public class Employee { public string FirstName { get; set; } public string MiddleName { get; set; } public string LastName { get; set; } public Address EmployeeAddress { get; set; } } I am trying to compare the following two employee instances: var emp1Address = new Address(); emp1Address.AddressLine1 = "Microsoft Corporation"; emp1Address.AddressLine2 = "One Microsoft Way"; emp1Address.City = "Redmond"; emp1Address.State = "WA"; emp1Address.Zip = "98052-6399"; var emp1 = new Employee(); emp1.FirstName = "Bill"; emp1.LastName = "Gates"; emp1.EmployeeAddress = emp1Address; var emp2Address = new Address(); emp2Address.AddressLine1 = "Gates Foundation"; emp2Address.AddressLine2 = "One Microsoft Way"; emp2Address.City = "Redmond"; emp2Address.State = "WA"; emp2Address.Zip = "98052-6399"; var emp2 = new Employee(); emp2.FirstName = "Melinda"; emp2.LastName = "Gates"; emp2.EmployeeAddress = emp2Address; So when I pass these two employee objects to my GetDifferingProperties method currently it returns FirstName and EmployeeAddress, but it does not tell me which exact property (which in this case is Address1) in the EmployeeAddress has changed. How can I tweak this method to get something like EmployeeAddress.Address1?

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  • Python. How to iterate through a list of lists looking for a partial match

    - by Becca Millard
    I'm completely stuck on this, without even an idea about how to wrap my head around the logic of this. In the first half of the code, I have successfully generation a list of (thousands of) lists of players names and efficiency scores: eg name_order_list = [["Bob", "Farley", 12.345], ["Jack", "Donalds", 14.567], ["Jack", "Donalds", 13.421], ["Jack", "Donalds", 15.232],["Mike", "Patricks", 10.543]] What I'm trying to do, is come up with a way to make a list of lists of the average efficiency of each player. So in that example, Jack Donalds appears multiple times, so I'd want to recognize his name somehow and average out the efficiency scores. Then sort that new list by efficiency, rather than name. So then the outcome would be like: average_eff_list = [[12.345, "Bob", "Farley"], [14.407, "Jack", "Donalds"], [10.543, "Mike", "Patricks"]] Here's what I tried (it's kind of a mess, but should be readable): total_list = [] odd_lines = [name_order_list[i] for i in range(len(name_order_list)) if i % 2 == 0] even_lines = [name_order_list[i] for i in range(len(name_order_list)) if i % 2 == 1] i = 0 j = i-1 while i <= 10650: iteration = 2 total_eff = 0 while odd_lines[i][0:2] == even_lines[i][0:2]: if odd_lines[i][0:2] == even_lines[j][0:2]: if odd_lines[j][0:2] != even_lines[j][0:2]: total_eff = even_lines[j][2]/(iteration-1) iteration -= 1 #account fr the single (rather than dual) additional entry else: total_eff = total_eff if iteration == 2: total_eff = (odd_lines[i][2] + even_lines[i][2]) / iteration else: total_eff = ((total_eff * (iteration - 2)) + (odd_lines[i][2] + even_lines[i][2])) / iteration iteration += 2 i += 1 j += 1 if i > 10650: break else: if odd_lines[i][0:2] == even_lines[j][0:2]: if odd_lines[j][0:2] != even_lines[j][0:2]: total_eff = (odd_lines[i][2] + even_lines[j][2]) / iteration else: total_eff = ((total_eff * (iteration -2)) + odd_lines[i][2]) / (iteration - 1) if total_eff == 0: #there's no match at all total_odd = [odd_lines[i][2], odd_lines[i][0], odd_lines[i][1]] total_list.append(total_odd) if even_lines[i][0:2] != odd_lines[i+1][0:2]: total_even = [even_lines[i][2], even_lines[i][0], even_lines[i][1]] else: total = [total_eff, odd_lines[i][0], odd_lines[i][1]] total_list.append(total) i += 1 if i > 10650: break else: print(total_list) Now, this runs well enough (doesn't get stuck or print someone's name multiple times) but the efficiency values are off by a large amount, so I know that scores are getting missed somewhere. This is a problem with my logic, I think, so any help would be greatly appreciated. As would any advice about how to loop through that massive list in a smarter way, since I'm sure there is one... EIDT: for this exercise, I need to keep it all in a list format. I can make new lists, but no using dictionaries, classes, etc.

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  • NHibernate : delete error

    - by MadSeb
    Hi, Model: I have a model in which one Installation can contain multiple "Computer Systems". Database: The table Installations has two columns Name and Description. The table ComputerSystems has three columsn Name, Description and InstallationId. Mappings: I have the following mapping for Installation: <?xml version="1.0" encoding="utf-8"?> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="myProgram.Core" namespace="myProgram"> <class name="Installation" table="Installations" lazy="true"> <id name="Id" column="Id" type="int"> <generator class="native" /> </id> <property name="Name" column="Name" type="string" not-null="true" /> <property name="Description" column="Description" type="string" /> <bag name="ComputerSystems" inverse="true" lazy="true" cascade="all-delete-orphan"> <key column="InstallationId" /> <one-to-many class="ComputerSystem" /> </bag> </class> </hibernate-mapping> I have the following mapping for ComputerSystem: <?xml version="1.0" encoding="utf-8"?> <id name="Id" column="ID" type="int"> <generator class="native" /> </id> <property name="Name" column="Name" type="string" not-null="true" /> <property name="Description" column="Description" type="string" /> <many-to-one name="Installation" column="InstallationID" cascade="save-update" not-null="true" /> Classes: The Installation class is: public class Installation { public virtual String Description { get; set; } public virtual String Name { get; set; } public virtual IList<ComputerSystem> ComputerSystems { get { if (_computerSystemItems== null) { lock (this) { if (_computerSystemItems== null) _computerSystemItems= new List<ComputerSystem>(); } } return _computerSystemItems; } set { _computerSystemItems= value; } } protected IList<ComputerSystem> _computerSystemItems; public Installation() { Description = ""; Name= ""; } } The ComputerSystem class is: public class ComputerSystem { public virtual String Name { get; set; } public virtual String Description { get; set; } public virtual Installation Installation { get; set; } } The issue is that I get an error when trying to delete an installation that contains a ComputerSystem. The error is: "deleted object would be re-saved by cascade (remove deleted object from associations)". Can anyone help ? Regards, Seb

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  • Custom activity designers in Workflow Foundation 3.5: How do they work?

    - by stakx
    Intent of this post: I realise that Workflow Foundation is not extremely popular on StackOverflow and that there will probably be not many answers, or none at all. This post is intended as a resource to people trying to customise workflow activities' appearance through custom designer classes. Goals: I am attempting to create a custom designer class for Workflow activities to achieve the following: Make activities look less technical. For example, I don't necessarily want to see the internal object name as the activity's "title" -- instead, I'd like to see something more descriptive. Display the values of certain properties beneath the title text. I would like to see some properties' values directly underneath the title so that I don't need to look somewhere else (namely, at the Properties window). Provide custom drop areas and draw custom internal arrows. As an example, I would like to be able to have custom drop areas in very specific places. What I found out so far: I created a custom designer class deriving from SequentialActivityDesigner as follows: [Designer(typeof(SomeDesigner))] public partial class SomeActivity: CompositeActivity { ... } class PlainDesigner : SequentialActivityDesigner { ... } Through overriding some properties and the OnPaint method, I found out about the following correspondences between the properties and how the activity will be displayed: Figure 1. Relationship between some properties of an SequentialActivityDesigner and the displayed activity. Possible solutions for goal #1 (make activities look less technical) and goal #2 (display values of properties beneath title text): The displayed title can be changed through the Title property. If more room is required to display additional information beneath the title, the TitleHeight property can be increased (ie., override the property and make it return base.TitleHeight + n, where n is some positive integer). Override the OnPaint method and draw additional text in the area reserved through TitleHeight. Open questions: What are the connectors, connections, and connection points used for? They seem to be necessary, but for what purpose? While the drop targets can be got through the GetDropTargets method, it seems that this is not necessarily where the designer will actually place dropped activities. When an activity is dragged across a workflow, the designer displays little green plus signs where activities can be dropped; how does it figure out the locations of these plus signs? How does the designer figure out where to draw connector lines and arrows?

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  • Executing a .NET Managed Assembly from SQL Server 2008 - Pro's, Con's & Recommendations

    - by RPM1984
    Hi guys, looking for opinions/recommendations/links for the following scenario im currently facing. The Platform: .NET 4.0 Web Application SQL Server 2008 The Task: Overhaul a component of the system that performs (fairly) complex mathematical operations based on a specific user activity, and updates numerous tables in the database. A common user activity might be "Bob" decides to post a forum topic. This results in (the end-solution) needing to look at various factors (about the post he did), then after doing some math based on lookup values/ratios as well as other data in the database, inserting some other data as a result of these operations. The Options: Ok - so here's what im thinking. Although it would be much easier to do this in C# (LINQ-SQL) it doesnt make much sense as the majority of the computations are based on values in the db, and it will get difficult to control/optimize/debug the LINQ over time. Hence, im leaning towards created a managed assembly (C# Class Library) that contains the lookup values (constants) as well as leveraging the math classes in the existing .NET BCL. Basically i'd expose a few methods that can be called by the T-SQL Stored Procedures. This to me has the following advantages: Simplicity of math. Do complex math in .NET vs complex math in T-SQL. No brainer. =) Abstraction of computatations, configurable "lookup" values and business logic from raw T-SQL. T-SQL only needs to care about the data, simplifying the stored procedures and making it easier to maintain. When it needs to do math it delegates off to the managed assembly. So, having said that - ive never done this before (call .NET assmembly from T-SQL), and after some googling the best site i could come up with is here, which is useful but outdated. So - what am i asking? Well, firstly - i need some better references on how to actually do this. "This" being how to call a C# .NET 4 Assembly from within T-SQL Stored Procedures in SQL Server 2008. Secondly, who out there has done this, what problems (if any) did you face? Realize this may be difficult to provide a "correct answer", so ill try to give it to whoever gives me the answer with a combination of good links and a list of pro's/con's/problems with this implementation. Cheers!

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  • problem in adding image to JFrame

    - by firestruq
    Hi, I'm having problems in adding a picture into JFrame, something is missing probebly or written wrong. here are the classes: main class: public class Tester { public static void main(String args[]) { BorderLayoutFrame borderLayoutFrame = new BorderLayoutFrame(); borderLayoutFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); borderLayoutFrame.setSize(600,600); borderLayoutFrame.setVisible(true); } } public class BorderLayoutFrame extends JFrame implements ActionListener { private JButton buttons[]; // array of buttons to hide portions private final String names[] = { "North", "South", "East", "West", "Center" }; private BorderLayout layout; // borderlayout object private PicPanel picture = new PicPanel(); // set up GUI and event handling public BorderLayoutFrame() { super( "Philosofic Problem" ); layout = new BorderLayout( 5, 5 ); // 5 pixel gaps setLayout( layout ); // set frame layout buttons = new JButton[ names.length ]; // set size of array // create JButtons and register listeners for them for ( int count = 0; count < names.length; count++ ) { buttons[ count ] = new JButton( names[ count ] ); buttons[ count ].addActionListener( this ); } add( buttons[ 0 ], BorderLayout.NORTH ); // add button to north add( buttons[ 1 ], BorderLayout.SOUTH ); // add button to south add( buttons[ 2 ], BorderLayout.EAST ); // add button to east add( buttons[ 3 ], BorderLayout.WEST ); // add button to west add( picture, BorderLayout.CENTER ); // add button to center } // handle button events public void actionPerformed( ActionEvent event ) { } } I'v tried to add the image into the center of layout. here is the image class: public class PicPanel extends JPanel { Image img; private int width = 0; private int height = 0; public PicPanel() { super(); img = Toolkit.getDefaultToolkit().getImage("table.jpg"); } public void paintComponent(Graphics g) { super.paintComponents(g); if ((width <= 0) || (height <= 0)) { width = img.getWidth(this); height = img.getHeight(this); } g.drawImage(img,0,0,width,height,this); } } Please your help, what is the problem? thanks BTW: i'm using eclipse, which directory the image suppose to be in?

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  • Killing Mysql prcoesses staying in sleep command.

    - by Shino88
    Hey I am connecting a MYSQL database through hibernate and i seem to have processes that are not being killed after they are finished in the session. I have called flush and close on each session but when i check the server the last processes are still there with a sleep command. This is a new problem which i am having and was not the case yesterday. Is there any way i can ensure the killng of theses processes when i am done with a session. Below is an example of one of my classes. public JSONObject check() { //creates a new session needed to add elements to a database Session session = null; //holds the result of the check in the database JSONObject check = new JSONObject(); try{ //creates a new session needed to add elements to a database SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory(); session = sessionFactory.openSession(); if (justusername){ //query created to select a username from user table String hquery = "Select username from User user Where username = ? "; //query created Query query = session.createQuery(hquery); //sets the username of the query the values JSONObject contents query.setString(0, username); // executes query and adds username string variable String user = (String) query.uniqueResult(); //checks to see if result is found (null if not found) if (user == null) { //adds false to Jobject if not found check.put("indatabase", "false"); } else { check.put("indatabase", "true"); } //adds check to Jobject to say just to check username check.put("justusername", true); } else { //query created to select a username and password from user table String hquery = "Select username from User user Where username = :user and password = :pass "; Query query = session.createQuery(hquery); query.setString("user", username); query.setString("pass", password); String user = (String) query.uniqueResult(); if(user ==null) { check.put("indatabase", false); } else { check.put("indatabase", true); } check.put("justusername", false); } }catch(Exception e){ System.out.println(e.getMessage()); //logg.log(Level.WARNING, " Exception", e.getMessage()); }finally{ // Actual contact insertion will happen at this step session.flush(); session.close(); } //returns Jobject return check; }

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  • C# Select clause returns system exception instead of relevant object

    - by Kashif
    I am trying to use the select clause to pick out an object which matches a specified name field from a database query as follows: objectQuery = from obj in objectList where obj.Equals(objectName) select obj; In the results view of my query, I get: base {System.SystemException} = {"Boolean Equals(System.Object)"} Where I should be expecting something like a Car, Make, or Model Would someone please explain what I am doing wrong here? The method in question can be seen here: // this function searches the database's table for a single object that matches the 'Name' property with 'objectName' public static T Read<T>(string objectName) where T : IEquatable<T> { using (ISession session = NHibernateHelper.OpenSession()) { IQueryable<T> objectList = session.Query<T>(); // pull (query) all the objects from the table in the database int count = objectList.Count(); // return the number of objects in the table // alternative: int count = makeList.Count<T>(); IQueryable<T> objectQuery = null; // create a reference for our queryable list of objects T foundObject = default(T); // create an object reference for our found object if (count > 0) { // give me all objects that have a name that matches 'objectName' and store them in 'objectQuery' objectQuery = from obj in objectList where obj.Equals(objectName) select obj; // make sure that 'objectQuery' has only one object in it try { foundObject = (T)objectQuery.Single(); } catch { return default(T); } // output some information to the console (output screen) Console.WriteLine("Read Make: " + foundObject.ToString()); } // pass the reference of the found object on to whoever asked for it return foundObject; } } Note that I am using the interface "IQuatable<T>" in my method descriptor. An example of the classes I am trying to pull from the database is: public class Make: IEquatable<Make> { public virtual int Id { get; set; } public virtual string Name { get; set; } public virtual IList<Model> Models { get; set; } public Make() { // this public no-argument constructor is required for NHibernate } public Make(string makeName) { this.Name = makeName; } public override string ToString() { return Name; } // Implementation of IEquatable<T> interface public virtual bool Equals(Make make) { if (this.Id == make.Id) { return true; } else { return false; } } // Implementation of IEquatable<T> interface public virtual bool Equals(String name) { if (this.Name.Equals(name)) { return true; } else { return false; } } } And the interface is described simply as: public interface IEquatable<T> { bool Equals(T obj); }

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  • How do we, as a community, help encourage programming in public schools? (Or state Schools for the U

    - by NoMoreZealots
    PRIMARY MOTIVATION My office gets involved with the "First Robotics" competitions and one thing that lingers year to year is the students typically have no preparation for doing even simple programming as part of the public schools system. While the science classes provide some basic grasp of mechanical and electrical concepts, by in large computer programming gets no coverage from the curriculum. (This my be different in other areas of the country/world.) What makes it worse is there is only a short period of time you have to prepare the student's and help them design the robot. Talking to some professors from local colleges, it's a problem because you can't assume even the most basic understanding for freshman CS majors. Languages like Python, Lua and BASIC are simple enough for at least high school level students, if not younger. SCOPE So how do you get public schools to support a programming, at least to the level of "Try it in BASIC" examples that used to be at the end of a chapter in my Algebra book? At least enough to prepare them for event's such as the FIRST Robotic competitions. Which the primary objectives are to teach problem solving and team work, and to possible foster an interest in Math, Science and Engineering in general. (Not force feed to them, as some people her seem to be implying.) Edit: Why teach kids: (Since 2000 CS enrollment in US colleges has decreased by 70% while college enrollment has increased, this is a PROBLEM.) Saying there is no value in teaching someone programming in Jr./High school because they might think "they know programming." Is like saying there's no value in teaching High school science and physics, because they might decide they "know physics." Leading to abuse like: "I passed a high school physics class, I'm going to develop a Unified Quantum Gravitational Theory." Better Prepared students are better students. Instead it would allows college programs to raise the bar on the entry level courses, allowing students to be weeded out based on their understanding of more advanced material. Plus people who did poorly in that in topic in High school aren't as likely to say "I think there's money in computer's so I'll computer science." Plus if people take it in high school and decide THEN that it's not for them, it's better than them wasting their money to PAY a college to figure that out. The result is that people who take the degree are more likely to succeed and be there for the RIGHT reasons. (i.e. It's what they REALLY want to do. And that's REALLY the key to being good at anything.) Programming is like anything else, the more practice and genuine interest you have the better you get. If you start them later, they get less practice. The earlier give them the opportunity to start, the more practice they will get. All other things equal, the more practice the better the programmer.

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  • IF Statement has strange behavior

    - by BSchlinker
    I've developed a 'custom' cout, so that I can display text to console and also print it to a log file. This cout class is passed a different integer on initialization, with the integer representing the verbosity level of the message. If the current verbosity level is greater then or equal to the verbosity level of the message, the message should print. The problem is, I have messages printing even when the current verbosity level is too low. I went ahead and debugged it, expecting to find the problem. Instead, I found multiple scenarios where my if statements are not working as expected. The statement if(ilralevel_passed <= ilralevel_set) will sometimes proceed even if ilralevel_set is LESS then ilralevel_passed. You can see this behavior in the following picture (my apologizes for using Twitpic) http://twitpic.com/1xtx4g/full. Notice how ilralevel_set is equal to zero, and ilralevel_passed is equal to one. Yet, the if statement has returned true and is now moving forward to pass the line to cout. I've never seen this type of behavior before and I'm not exactly sure how to proceed debugging it. I'm not able to isolate the behavior either -- it only occurs in certain parts of my program. Any suggestions are appreciated as always. // Here is an example use of the function: // ilra_status << setfill('0') << setw(2) << dispatchtime.tm_sec << endl; // ilra_warning << "Dispatch time (seconds): " << mktime(&dispatchtime) << endl; // Here is the 'custom' cout function: #ifndef ILRA_H_ #define ILRA_H_ // System libraries #include <iostream> #include <ostream> #include <sstream> #include <iomanip> // Definitions #define ilra_talk ilra(__FUNCTION__,0) #define ilra_update ilra(__FUNCTION__,0) #define ilra_error ilra(__FUNCTION__,1) #define ilra_warning ilra(__FUNCTION__,2) #define ilra_status ilra(__FUNCTION__,3) // Statics static int ilralevel_set = 0; static int ilralevel_passed; // Classes class ilra { public: // constructor / destructor ilra(const std::string &funcName, int toset) { ilralevel_passed = toset; } ~ilra(){}; // enable / disable irla functions static void ilra_verbose_level(int toset){ ilralevel_set = toset; } // output template <class T> ilra &operator<<(const T &v) { if(ilralevel_passed <= ilralevel_set) std::cout << v; return *this; } ilra &operator<<(std::ostream&(*f)(std::ostream&)) { if(ilralevel_passed <= ilralevel_set) std::cout << *f; return *this; } }; // end of the class #endif /* ILRA_H_ */

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  • How to initiate chatting between two clients and two clients only, using applets and servlets?

    - by mithun1538
    Hello everyone, I first need to apologize for my earlier questions. (You can check my profile for them)They seemed to ask more questions than give answers. Hence, I am laying down the actual question that started all them absurd questions. I am trying to design a chat applet. Till now, I have coded the applet, servlet and communication between the applet and the servlet. The code in the servlet side is such that I was able to establish chatting between clients using the applets, but the code was more like a broadcast all feature, i.e. all clients would be chatting with each other. That was my first objective when I started designing the chat applet. The second step is chatting between only two specific users, much like any other chat application we have. So this was my idea for it: I create an instance of the servlet that has the 'broadcast-all' code. I then pass the address of this instance to the respective clients. 2 client applets use the address to then chat. Technically the code is 'broadcast-all', but since only 2 clients are connected to it, it gives the chatting between two clients feature. Thus, groups of 2 clients have different instances of the same servlet, and each instance handles chatting between two clients at a max. However, as predicted, the idea didn't materialize! I tried to create an instance of the servlet but the only solution for that was using sessions on the servlet side, and I don't know how to use this session for later communications. I then tried to modify my broadcast-all code. In that code, I was using classes that implemented Observer and Observable interfaces. So the next idea that I got was: Create a new object of the Observable class(say class_1). This object be common to 2 clients. 2 clients that wish to chat will use same object of the class_1. 2 other clients will use a different object of class_1. But the problem here lies with the class that implements the Observer interface(say class_2). Since this has observers monitoring the same type of class, namely class_1, how do I establish an observer monitoring one object of class_1 and another observer monitoring another object of the same class class_1 (Because notifyObservers() would notify all the observers and I can't assign a particular observer to a particular object)? I first decided to ask individual problems, like how to create instances of servlets, using objects of observable and observer and so on in stackoverflow... but I got confused even more. Can anyone give me an idea how to establish chatting between two clients only?(I am using Http and not sockets or RMI). Regards, Mithun. P.S. Thanks to all who replied to my previous (absurd) queries. I should have stated the purpose earlier so that you guys could help me better.

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  • Unlocking a mutex from a different thread (C++)

    - by dan
    I'm using the C++ boost::thread library, which in my case means I'm using pthreads. Officially, a mutex must be unlocked from the same thread which locks it, and I want the effect of being able to lock in one thread and then unlock in another. There are many ways to accomplish this. One possibility would be to write a new mutex class which allows this behavior. For example: class inter_thread_mutex{ bool locked; boost::mutex mx; boost::condition_variable cv; public: void lock(){ boost::unique_lock<boost::mutex> lck(mx); while(locked) cv.wait(lck); locked=true; } void unlock(){ { boost::lock_guard<boost::mutex> lck(mx); if(!locked) error(); locked=false; } cv.notify_one(); } // bool try_lock(); void error(); etc. } I should point out that the above code doesn't guarantee FIFO access, since if one thread calls lock() while another calls unlock(), this first thread may acquire the lock ahead of other threads which are waiting. (Come to think of it, the boost::thread documentation doesn't appear to make any explicit scheduling guarantees for either mutexes or condition variables). But let's just ignore that (and any other bugs) for now. My question is, if I decide to go this route, would I be able to use such a mutex as a model for the boost Lockable concept. For example, would anything go wrong if I use a boost::unique_lock< inter_thread_mutex for RAII-style access, and then pass this lock to boost::condition_variable_any.wait(), etc. On one hand I don't see why not. On the other hand, "I don't see why not" is usually a very bad way of determining whether something will work. The reason I ask is that if it turns out that I have to write wrapper classes for RAII locks and condition variables and whatever else, then I'd rather just find some other way to achieve the same effect.

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  • Container item implementation

    - by onurozcelik
    Hi, I am working in Train Traffic Controller software project. My responsibility in this project is to develop the visual railroad GUI. We are implementing the project with Qt. By now I am using QGraphicsLinearLayout to hold my items. I am using the layout because I do not want to calculate coordinates of each item. So far I wrote item classes to add the layout. For instance SwitchItem class symbolizes railroad switch in real world. Each item class is responsible for its own painting and events. So far so good. Now I need a composite item that can contain two or more item. This class is going to be responsible for painting the items contained in it. I need this class because I have to put two or more items inside same layout cell. If I don' t put them in same cell I can' t use layout. See the image below. BlockSegmentItem and SignalItem inside same cell. Here is my compositeitem implementation. #include "compositeitem.h" CompositeItem::CompositeItem(QString id,QList<FieldItem *> _children) { children = _children; } CompositeItem::~CompositeItem() { } QRectF CompositeItem::boundingRect() const { FieldItem *child; QRectF rect(0,0,0,0); foreach(child,children) { rect = rect.united(child->boundingRect()); } return rect; } void CompositeItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget ) { FieldItem *child; foreach(child,children) { child->paint(painter,option,widget); } } QSizeF CompositeItem::sizeHint(Qt::SizeHint which, const QSizeF &constraint) const { QSizeF itsSize(0,0); FieldItem *child; foreach(child,children) { // if its size empty set first child size to itsSize if(itsSize.isEmpty()) itsSize = child->sizeHint(Qt::PreferredSize); else { QSizeF childSize = child->sizeHint(Qt::PreferredSize); if(itsSize.width() < childSize.width()) itsSize.setWidth(childSize.width()); itsSize.setHeight(itsSize.height() + childSize.height()); } } return itsSize; } void CompositeItem::contextMenuEvent(QGraphicsSceneContextMenuEvent *event) { qDebug()<<"Test"; } This code works good with painting but when it comes to item events it is problematic. QGraphicsScene treats the composite item like a single item which is right for layout but not for events. Because each item has its own event implementation.(e.g. SignalItem has its special context menu event.) I have to handle item events seperately. Also I need a composite item implementation for the layout. How can I overcome this dilemma?

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  • Creating and writing file from a FileOutputStream in Java

    - by Althane
    Okay, so I'm working on a project where I use a Java program to initiate a socket connection between two classes (a FileSender and FileReceiver). My basic idea was that the FileSender would look like this: try { writer = new DataOutputStream(connect.getOutputStream()); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } //While we have bytes to send while(filein.available() >0){ //We write them out to our buffer writer.write(filein.read(outBuffer)); writer.flush(); } //Then close our filein filein.close(); //And then our socket; connect.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); The constructor contains code that checks to see if the file exists, and that the socket is connected, and so on. Inside my FileReader is this though: input = recvSocket.accept(); BufferedReader br = new BufferedReader(new InputStreamReader(input.getInputStream())); FileOutputStream fOut= new FileOutputStream(filename); String line = br.readLine(); while(line != null){ fOut.write(line.getBytes()); fOut.flush(); line = br.readLine(); } System.out.println("Before RECV close statements"); fOut.close(); input.close(); recvSocket.close(); System.out.println("After RECV clsoe statements"); All inside a try-catch block. So, what I'm trying to do is have the FileSender reading in the file, converting to bytes, sending and flushing it out. FileReceiver, then reads in the bytes, writes to the fileOut, flushes, and continues waiting for more. I make sure to close all the things that I open, so... here comes the weird part. When I try and open the created text file in Eclipse, it tells me "An SWT error has occured ... recommended to exit the workbench... see .log for more details.". Another window pops up saying "Unhandled event loop exception, (no more handles)". However, if I try to open the sent text file in notepad2, I get ThisIsASentTextfile Which is good (well, minus the fact that there should be line breaks, but I'm working on that...). Does anyone know why this is happening? And while we're checking, how to add the line breaks? (And is this a particularly bad way to transfer files over java without getting some other libraries?)

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  • Entity Framework looking for wrong column

    - by m.edmondson
    I'm brand new to the Entity Framework and trying to learn all it can offer. I'm currently working my way through the MVC Music Store tutorial which includes the following code: public ActionResult Browse(string genre) { // Retrieve Genre and its Associated Albums from database var genreModel = storeDB.Genres.Include("Albums") .Single(g => g.Name == genre); return View(genreModel); } as I'm working in VB I converted it like so: Function Browse(ByVal genre As String) As ActionResult 'Retrieve Genre and its Associated Albums from database Dim genreModel = storeDB.Genres.Include("Albums"). _ Single(Function(g) g.Name = genre) Return(View(genreModel)) End Function The problem is I'm getting the following exception: Invalid column name 'GenreGenreId'. Which I know is true, but I can't for the life of my work out where it's getting 'GenreGenreId' from. Probably a basic question but I'll appreciate any help in the right direction. As per requested here is the source for my classes: Album.vb Public Class Album Private _title As String Private _genre As Genre Private _AlbumId As Int32 Private _GenreId As Int32 Private _ArtistId As Int32 Private _Price As Decimal Private _AlbumArtUrl As String Public Property Title As String Get Return _title End Get Set(ByVal value As String) _title = value End Set End Property Public Property AlbumId As Int16 Get Return _AlbumId End Get Set(ByVal value As Int16) _AlbumId = value End Set End Property Public Property GenreId As Int16 Get Return _GenreId End Get Set(ByVal value As Int16) _GenreId = value End Set End Property Public Property ArtistId As Int16 Get Return _ArtistId End Get Set(ByVal value As Int16) _ArtistId = value End Set End Property Public Property AlbumArtUrl As String Get Return _AlbumArtUrl End Get Set(ByVal value As String) _AlbumArtUrl = value End Set End Property Public Property Price As Decimal Get Return _Price End Get Set(ByVal value As Decimal) _Price = value End Set End Property Public Property Genre As Genre Get Return _genre End Get Set(ByVal value As Genre) _genre = value End Set End Property End Class Genre.vb Public Class Genre Dim _genreId As Int32 Dim _Name As String Dim _Description As String Dim _Albums As List(Of Album) Public Property GenreId As Int32 Get Return _genreId End Get Set(ByVal value As Int32) _genreId = value End Set End Property Public Property Name As String Get Return _Name End Get Set(ByVal value As String) _Name = value End Set End Property Public Property Description As String Get Return _Description End Get Set(ByVal value As String) _Description = value End Set End Property Public Property Albums As List(Of Album) Get Return _Albums End Get Set(ByVal value As List(Of Album)) _Albums = value End Set End Property End Class MusicStoreEntities.vb Imports System.Data.Entity Namespace MvcApplication1 Public Class MusicStoreEntities Inherits DbContext Public Property Albums As DbSet(Of Album) Public Property Genres As DbSet(Of Genre) End Class End Namespace

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