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  • Perl - Calling subclass constructor from superclass (OO)

    - by Emmel
    This may turn out to be an embarrassingly stupid question, but better than potentially creating embarrassingly stupid code. :-) This is an OO design question, really. Let's say I have an object class 'Foos' that represents a set of dynamic configuration elements, which are obtained by querying a command on disk, 'mycrazyfoos -getconfig'. Let's say that there are two categories of behavior that I want 'Foos' objects to have: Existing ones: one is, query ones that exist in the command output I just mentioned (/usr/bin/mycrazyfoos -getconfig`. Make modifications to existing ones via shelling out commands. Create new ones that don't exist; new 'crazyfoos', using a complex set of /usr/bin/mycrazyfoos commands and parameters. Here I'm not really just querying, but actually running a bunch of system() commands. Affecting changes. Here's my class structure: Foos.pm package Foos, which has a new($hashref-{name = 'myfooname',) constructor that takes a 'crazyfoo NAME' and then queries the existence of that NAME to see if it already exists (by shelling out and running the mycrazyfoos command above). If that crazyfoo already exists, return a Foos::Existing object. Any changes to this object requires shelling out, running commands and getting confirmation that everything ran okay. If this is the way to go, then the new() constructor needs to have a test to see which subclass constructor to use (if that even makes sense in this context). Here are the subclasses: Foos/Existing.pm As mentioned above, this is for when a Foos object already exists. Foos/Pending.pm This is an object that will be created if, in the above, the 'crazyfoo NAME' doesn't actually exist. In this case, the new() constructor above will be checked for additional parameters, and it will go ahead and, when called using -create() shell out using system() and create a new object... possibly returning an 'Existing' one... OR As I type this out, I am realizing it is perhaps it's better to have a single: (an alternative arrangement) Foos class, that has a -new() that takes just a name -create() that takes additional creation parameters -delete(), -change() and other params that affect ones that exist; that will have to just be checked dynamically. So here we are, two main directions to go with this. I'm curious which would be the more intelligent way to go.

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  • Use a subclass object to modify a protected propety within its superclass object

    - by gadmeer
    Sorry for the crappy title I failed to think of a better version for my Java question. I am right now using Java version: 1.6.0_18 and Netbeans version: 6.8 Now for the question. What I've done is created a class with only one protected int property and next I made a public method to Set the int property to a given value. Then I made an object of that class and used said public method to set the int property to 5. Now I need your help to create another class that will take said object and expose it's protected int property. The way I could think of doing this was to create a sub class to inherit said class and then create a method to Get the int property of the super class. I kind of succeeded to create the code to Get the int property but now I can't figure out how to use this new sub class to reference the object of the super class. Here are the 2 classes I have thus far: public class A { protected int iNumber; public void setNumber ( int aNumber ) { iNumber = aNumber; } } public class B extends A { public int getNumber() { return super.iNumber; } } I created an object of 'A' and used its method to set its property to 5, like this: A objA = new A(); objA.setNumber ( 5 ); Now I want to create an object of 'B' to output the int stored within the property of 'objA'. I've tried to run this code: B objB = (B) objA; String aNumber_String = String.valueOf( objB.getNumber() ); System.out.println( aNumber_String ); but I got the error: "java.lang.ClassCastException" on the first line B objB = (B) objA; Please is there anyway of doing what I am trying to do? P.S. I am hoping to make this idea work because I do not want to edit class A (unless I have no choice) by giving it a getter method. P.P.S Also I know it's a 'bad' idea to expose the property instead of making it private and use public setter / getter methods but I like it this way :). Edit: Added code tags

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  • Is it possible to access variable of subclass using object of superclass in polymorphism

    - by fari
    how can i access state varibale of class keyboard with object of class kalaplayer /** * An abstract class representing a player in Kala. Extend this class * to make your own players (e.g. human players entering moves at the keyboard * or computer players with programmed strategies for making moves). */ public abstract class KalaPlayer { /** * Method by which a player selects a move. * @param gs The current game state * @return A side pit number in the range 1-6 * @throws NoMoveAvailableException if all side pits for the player are empty * (i.e. the game is over) */ public abstract int chooseMove(KalaGameState gs) throws NoMoveAvailableException; } public class KeyBoardPlayer extends KalaPlayer { /** * Method by which a player selects a move. * @param gs The current game state * @return A side pit number in the range 1-6 * @throws NoMoveAvailableException if all side pits for the player are empty * (i.e. the game is over) */ public KalaGameState state; public KeyBoardPlayer() { System.out.println("Enter the number of stones to play with: "); try { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); int key = Integer.parseInt(br.readLine()); state=new KalaGameState(key); //key=player1.state.turn; } catch(IOException e) { System.out.println(e); } } public int chooseMove(KalaGameState gs) throws NoMoveAvailableException{ return 0; } } import java.io.IOException; import java.io.BufferedReader; import java.io.InputStreamReader; public class KalaGame { KalaPlayer player1,player2; public KalaGame(KeyBoardPlayer Player1,KeyBoardPlayer Player2) { //super(0); player1=new KeyBoardPlayer(); player2 = new KeyBoardPlayer(); //player1=Player1; //player2=Player2; //player1.state ****how can i access the stae variable from Keyboard CLass using object from KalaPlayer key=player1.state.turn; } public void play() { System.out.println("Enter the number of stones to play with: "); try { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); int key = Integer.parseInt(br.readLine()); System.out.println(key); KalaGameState state=new KalaGameState(key); printGame(); } catch(IOException e) { System.out.println(e); } }

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  • Hibernate -using Table per subclass - how to link an existing superclass object to a sibclass object

    - by Chandni
    Hi, I have a User hibernate class, Clerk class and Consumer class. All these maps to their own tables in database. The User PK also acts as Clerk's and Consumer's PK. So now my problem is that if a user is initially a Clerk, he has a record in Users table and Clerks table. If that user wants to become a consumer, I want to link that User's record to the new Consumer's record. So even if I pass the userId to the consumer's record, it treats it as a new User to be persisted and gives a duplicate_key exception. How do I tell Hiernate to link the same user object with this new Consumer object. Thanks in advance, -Chandni

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  • UIImageView subclass with CGRectIntersectsRect - help!

    - by Flafla2
    The title of this question should be pretty self explanatory. I am making an app that involves multiple UIImageViews that serve the same purpose. They are merely different sizes. Anyway, I decided that the best solution was to make UIImageView subclasses, link the subcalsses in IB, and work from there. My code should explain this better - #define kPausedStatePaused 1 #define kPausedStatePlay 2 #import "Game.h" #import "ScoreSystem.h" @interface Doctor : UIImageView { } @end @interface Ground : UIImageView { } @end @interface Wall : UIImageView { } @end @interface Electric_Wire : UIImageView { } @end @implementation Game /* // The designated initializer. Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad. - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) { // Custom initialization } return self; } */ /* // Implement viewDidLoad to do additional setup after loading the view, typically from a nib. - (void)viewDidLoad { [super viewDidLoad]; } */ - (IBAction)pause { UIAlertView *pause = [[UIAlertView alloc] initWithTitle:@"Pause" message:nil delegate:self cancelButtonTitle:@"Quit" otherButtonTitles:@"Play", nil]; [pause show]; [pause release]; pauseint = kPausedStatePaused; } - (void)viewDidAppear { pauseint = kPausedStatePlay; } - (void)loop { Doctor *doctorview; Ground *groundview; if (CGRectIntersectsRect(doctorview, groundview)) { } } - (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex { if ([alertView.title isEqual:@"Pause"]) { if(buttonIndex == 0) [self dismissModalViewControllerAnimated:YES]; pauseint = kPausedStatePlay; } } // Override to allow orientations other than the default portrait orientation. - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { // Return YES for supported orientations return (interfaceOrientation == UIInterfaceOrientationLandscapeRight); } - (void)didReceiveMemoryWarning { // Releases the view if it doesn't have a superview. [super didReceiveMemoryWarning]; // Release any cached data, images, etc that aren't in use. } - (void)viewDidUnload { // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; } - (void)dealloc { [super dealloc]; } @end Unsurprisingly, Xcode gave me an "incompatible type for CGRectIntersectsRect" error.

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  • Accessing subclass members from a superclass pointer C++

    - by Dr. Monkey
    I have an array of custom class Student objects. CourseStudent and ResearchStudent both inherit from Student, and all the instances of Student are one or the other of these. I have a function to go through the array, determine the subtype of each Student, then call subtype-specific member functions on them. The problem is, because these functions are not overloaded, they are not found in Student, so the compiler kicks up a fuss. If I have a pointer to Student, is there a way to get a pointer to the subtype of that Student? Would I need to make some sort of fake cast here to get around the compile-time error?

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  • Hibernate subclass with foreign key relationships

    - by shikarishambu
    I need some help defining the following object hierarchy/ database relationship in Hibernate From the object sense – Agent is inherited from Person and Agency is inherited from Organization. they are inherited from Party which can have multiple Addresses associated with it The database consists of Agent - ID - Name -PartyID (references Party.ID) Agency -ID -Name -PartyID (references Party.ID) Address -AddrID -PartyID (references Party.ID) -Street Party. -PartyID

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  • Accessing super class function using subclass object

    - by bdhar
    I have an object for a subclass who is of it's superclass type. There is a overridden function in subclass which gets executed when called using the object. How to call the parent's function using the same object? Is there any way to achieve this? package supercall; public class Main { public static void main(String[] args) { SomeClass obj = new SubClass(); obj.go(); } } class SomeClass { SomeClass() { } public void go() { System.out.println("Someclass go"); } } class SubClass extends SomeClass { SubClass() { } @Override public void go() { System.out.println("Subclass go"); } } Consider the code above. Here it prints Subclass go . Instead I have to print Superclass go .

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  • Call a method of subclass in Java

    - by eyecreate
    If I have a base class Base thing = null; of which there is a subclass class Subclass extends Base and I instigate it as thing = new Subclass how would I call a method that is specifically in Subclass, but not in Base? ex. Base has only method() Subclass has method() and specialMethod() the method specialMethod() is the one I want to call.

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  • How can I share variables between a base class and subclass in Perl?

    - by Jonathan
    I have a base class like this: package MyClass; use vars qw/$ME list of vars/; use Exporter; @ISA = qw/Exporter/; @EXPORT_OK = qw/ many variables & functions/; %EXPORT_TAGS = (all => \@EXPORT_OK ); sub my_method { } sub other_methods etc { } --- more code--- I want to subclass MyClass, but only for one method. package MySubclass; use MyClass; use vars qw/@ISA/; @ISA = 'MyClass'; sub my_method { --- new method } And I want to call this MySubclass like I would the original MyClass, and still have access to all of the variables and functions from Exporter. However I am having problems getting the Exporter variables from the original class, MyClass, to export correctly. Do I need to run Exporter again inside the subclass? That seems redundant and unclear. Example file: #!/usr/bin/perl use MySubclass /$ME/; -- rest of code But I get compile errors when I try to import the $ME variable. Any suggestions?

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  • Why Can't I import a UITableViewCell subclass ? That's weird....

    - by user320064
    It's like this, I created a UITableViewCell subclass called NewsItemCell, then I wanna use it in my FirstViewController.m, then I tried to import it, but the compiler keeps telling me this Below is my code, it is driving me mad, thank you if you can help. import "NewsItemCell.h" import "FirstViewController.h" @implementation FirstViewController @synthesize computers; (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"NewsItemCellIdentifier"; NewsItemcell *cell = (NewsItemcell *)[tableView dequeueReusableCellWithIdentifier: CellIdentifier]; if (cell == nil) { NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"NewsItemCell" owner:self options:nil]; for (id oneObject in nib) if ([oneObject isKindOfClass:[NewsItemcell class]]) cell = (NewsItemcell *)oneObject; } NSUInteger row = [indexPath row]; NSDictionary *rowData = [self.computers objectAtIndex:row]; cell.newsTitle.text = [rowData objectForKey:@"Color"]; cell.newsDate.text = [rowData objectForKey:@"Name"]; return cell; } Jason

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  • Strategies for invoking subclass methods on generic objects

    - by Brad Patton
    I've run into this issue in a number of places and have solved it a bunch of different ways but looking for other solutions or opinions on how to address. The scenario is when you have a collection of objects all based off of the same superclass but you want to perform certain actions based only on instances of some of the subclasses. One contrived example of this might be an HTML document made up of elements. You could have a superclass named HTMLELement and subclasses of Headings, Paragraphs, Images, Comments, etc. To invoke a common action across all of the objects you declare a virtual method in the superclass and specific implementations in all of the subclasses. So to render the document you could loop all of the different objects in the document and call a common Render() method on each instance. It's the case where again using the same generic objects in the collection I want to perform different actions for instances of specific subclass (or set of subclasses). For example (an remember this is just an example) when iterating over the collection, elements with external links need to be downloaded (e.g. JS, CSS, images) and some might require additional parsing (JS, CSS). What's the best way to handle those special cases. Some of the strategies I've used or seen used include: Virtual methods in the base class. So in the base class you have a virtual LoadExternalContent() method that does nothing and then override it in the specific subclasses that need to implement it. The benefit being that in the calling code there is no object testing you send the same message to each object and let most of them ignore it. Two downsides that I can think of. First it can make the base class very cluttered with methods that have nothing to do with most of the hierarchy. Second it assumes all of the work can be done in the called method and doesn't handle the case where there might be additional context specific actions in the calling code (i.e. you want to do something in the UI and not the model). Have methods on the class to uniquely identify the objects. This could include methods like ClassName() which return a string with the class name or other return values like enums or booleans (IsImage()). The benefit is that the calling code can use if or switch statements to filter objects to perform class specific actions. The downside is that for every new class you need to implement these methods and can look cluttered. Also performance could be less than some of the other options. Use language features to identify objects. This includes reflection and language operators to identify the objects. For example in C# there is the is operator that returns true if the instance matches the specified class. The benefit is no additional code to implement in your object hierarchy. The only downside seems to be the lack of using something like a switch statement and the fact that your calling code is a little more cluttered. Are there other strategies I am missing? Thoughts on best approaches?

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  • pyQt4: QWidget subclass not responding to new setStyleSheet() background colour

    - by Ronny
    I am having an issue with PyQt4. I want to create a new widget within a window, and I want this widget to have a custom color. When i create a subclass of the QWidget class, and instantiate it, I am not able to change its background color through the setStyleSheet() function. When I instantiate a new QWidget object, I have no problems in changing its background color. But i dont want an ordinary QWidget object.I want to create my own subclass of QWidget. When i create a subclass of a QPushButton, I am also able to change its background color using the setStyleSheet() function. There are no error messages or warnings in the console window, it just refuses to work properly without any indication as to why. So what i would like to know is why is it that i can change the background color of a widget if i simply create a QWidget object, or a subclass of QPushButton, but not when i create a subclass of QWidget. And how can i therefore change the background color of an object that is a subclass of QWidget? Is it maybe something specific to the version of python or PyQt that i am using? Is it a bug in the library? or some flaw in the way that i am writing my code? I am using python 2.6.4 and PyQt4 Below is an example of the code that leads me to trouble. There are three widgets within the window one below the other. The parent widget is set with background color of green. The top widget is set to red, the middle one, is the subclass of QWidget, which should be blue, but it appears invisible because it takes on the color of the parent window for some reason. and the bottom widget is a subclass of QPushButton and is white. import sys from PyQt4 import QtGui, QtCore ################################################################################ #--------------------------------------------------------- CUSTOM WIDGET CLASS 1 class CustomWidget(QtGui.QWidget): def __init__(self, parent): QtGui.QWidget.__init__(self, parent) # some custom properties and functions will follow ################################################################################ #--------------------------------------------------------- CUSTOM WIDGET CLASS 2 class CustomWidget2(QtGui.QPushButton): def __init__(self, parent): QtGui.QPushButton.__init__(self, parent) # some custom properties and functions will follow ################################################################################ #----------------------------------------------------------- PARENT WIDGET CLASS class Parent(QtGui.QWidget): def __init__(self, parent=None): #---------------------------------------------------------- SETUP WINDOW QtGui.QWidget.__init__(self, parent) self.resize(500, 340) self.setStyleSheet("QWidget {background-color: #00FF00}") #-------------------------------------------------- SETUP DEFAULT WIDGET wid1 = QtGui.QWidget(self) wid1.setGeometry(10, 10, 480, 100) wid1.setStyleSheet("QWidget {background-color: #FF0000 }") #------------------------------------------------- SETUP CUSTOM WIDGET 1 wid2 = CustomWidget(self) wid2.setGeometry(10, 120, 480, 100) wid2.setStyleSheet("QWidget {background-color: #0000FF }") for i in dir(wid2): print i #------------------------------------------------- SETUP CUSTOM WIDGET 2 wid3 = CustomWidget2(self) wid3.setGeometry(10, 230, 480, 100) wid3.setStyleSheet("QWidget {background-color: #FFFFFF }") ################################################################################ #-------------------------------------------------------------------------- MAIN app = QtGui.QApplication(sys.argv) win = Parent() win.show() app.exec_()

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  • nhibernate subclass in code

    - by Antonio Nakic Alfirevic
    I would like to set up table-per-classhierarchy inheritance in nhibernate thru code. Everything else is set in XML mapping files except the subclasses. If i up the subclasses in xml all is well, but not from code. This is the code i use - my concrete subclass never gets created:( //the call NHibernate.Cfg.Configuration config = new NHibernate.Cfg.Configuration(); SetSubclass(config, typeof(TAction), typeof(tActionSub1), "Procedure"); //the method public static void SetSubclass(Configuration configuration, Type baseClass, Type subClass, string discriminatorValue) { PersistentClass persBaseClass = configuration.ClassMappings.Where(cm => cm.MappedClass == baseClass).Single(); SingleTableSubclass persSubClass = new SingleTableSubclass(persBaseClass); persSubClass.ClassName = subClass.AssemblyQualifiedName; persSubClass.DiscriminatorValue = discriminatorValue; persSubClass.EntityPersisterClass = typeof(SingleTableEntityPersister); persSubClass.ProxyInterfaceName = (subClass).AssemblyQualifiedName; persSubClass.NodeName = subClass.Name; persSubClass.EntityName = subClass.FullName; persBaseClass.AddSubclass(persSubClass); } the Xml mapping looks like this: <?xml version="1.0" encoding="utf-8" ?> <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" namespace="Riz.Pcm.Domain.BusinessObjects" assembly="Riz.Pcm.Domain"> <class name="Riz.Pcm.Domain.BusinessObjects.TAction, Riz.Pcm.Domain" table="dbo.tAction" lazy="true"> <id name="Id" column="ID"> <generator class="guid" /> </id> <discriminator type="String" formula="(select jt.Name from TJobType jt where jt.Id=JobTypeId)" insert="true" force="false"/> <many-to-one name="Session" column="SessionID" class="TSession" /> <property name="Order" column="Order1" /> <property name="ProcessStart" column="ProcessStart" /> <property name="ProcessEnd" column="ProcessEnd" /> <property name="Status" column="Status" /> <many-to-one name="JobType" column="JobTypeID" class="TJobType" /> <many-to-one name="Unit" column="UnitID" class="TUnit" /> <bag name="TActionProperties" lazy="true" cascade="all-delete-orphan" inverse="true" > <key column="ActionID"></key> <one-to-many class="TActionProperty"></one-to-many> </bag> <!--<subclass name="Riz.Pcm.Domain.tActionSub" discriminator-value="ZPower"></subclass>--> </class> </hibernate-mapping> What am I doing wrong? I can't find any examples on google:(

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  • Javascript: Inherit method from base class and return the subclass's private variable

    - by marisbest2
    I have the following BaseClass defined: function BaseClass (arg1,arg2,arg3) { //constructor code here then - var privateVar = 7500; this.getPrivateVar = function() { return privateVar; }; } I want to have the following subclass which allows changing privateVar like so: function SubClass (arg1,arg2,arg3,privateVar) { //constructor code here then - var privateVar = privateVar; } SubClass.prototype = new BaseClass(); Now I want SubClass to inherit the getPrivateVar method. However, when I try this, it always returns 7500 which is the value in the BaseClass and not the value of privateVar. In other words, is it possible to inherit a BaseClass's public methods but have any references in them refer to the SubClass's properties? And how would I do that?

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  • Handle cases where Nhibernate subclass does not exist

    - by kaykayman
    I have a scenario where I am using nhibernate to map records from one table to several different derived classes based on a discriminator. public class BaseClass { } public class DerivedClass0 : BaseClass { } public class DerivedClass1 : BaseClass { } public class DerivedClass2 : BaseClass { } I then use nhibernate's DiscriminateSubClassesOnColumn() method and alter the configuration to include <subclass name="DerivedClass0" extends="BaseClass" discriminator-value="discriminator0" /> <subclass name="DerivedClass1" extends="BaseClass" discriminator-value="discriminator1" /> <subclass name="DerivedClass2" extends="BaseClass" discriminator-value="discriminator2" /> so that when mapped, these classes are cast to their derived classes and not BaseClass. However, there are some records in my database which have a discriminator which does not have a corresponding subclass. In these cases, nHibernate throws an error: "Object with id: 'xxx' was not of the specified subclass..." Is there some way I can handle this, so that any records which do not have a corresponding subclass are cast to BaseClass rather than an error being thrown? I have simplified the above as much as possible, however it is worth noting that the XML is edited dynamically which is why I am referencing fluent nhibernate [DiscriminateSubClassesOnColumn()] and XML at the same time. The following things (which would help) are not an option: I cannot correct the data to remove records which are invalid I cannot create subclasses for those records which do not have one I need to handle cases where nHibernate tries to map on a discriminator and finds that one does not exist.

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  • Hibernate: How do I link a subclass to its superclass?

    - by Markus
    Hey there! I'm having a little problem setting up my webshop project. Thing is, I have a User() superclass and two subclasses, PrivateUser and BusinessUser. Now, I'm not quite sure how to get my head around storing this relationship via hibernate. For the purpose of this question, the User() class contains only one field: String address; the PrivateUser contains: String firstName; and the BusinessUser contains: String CompanyName; Each field has its getter and setter. As is right now, I would only store and be able to get firstName and companyName. When I fetch a user from my DB using Hibernate I would get a PrivateUser/BusinessUser with a null address. Bottom line is, could someone point me towards a useful tutorial or better yet show a similar example code? Thanks!

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  • Can I avoid explicitly casting objects with a common subclass?

    - by prendio2
    I have an iPodLibraryGroup object and Artist and Album both inherit from it. When it comes to my view controllers though I find that I'm duplicate lots of code, for example I have an ArtistListViewController and and AlbumListViewController even though they're both doing basically the same thing. The reason I've ended up duplicating the code is because these view controllers each refer to either an Artist object or al Album object and I'm not sure how to set it up so that one view controller could handle both — these view controllers are mainly accessing methods that that the objects have in common from iPodLibraryGroup. As an example, to hopefully make this clearer consider this code in AlbumListViewController: - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { Album *album = nil; album = [self albumForRowAtIndexPath:indexPath inTableView:tableView]; … if (!album.thumbnail) { [self startThumbnailDownload:album forIndexPath:indexPath inTableView:tableView]; cell.imageView.image = [UIImage imageNamed:@"Placeholder.png"]; } else { cell.imageView.image = album.thumbnail; } return cell; } This is essentially completely repeated (along with a hell of a lot more repeated code) in ArtistListViewController just so that I can typecast the local variable as an Artist instead of an Album. Is there a way to not explicitly need to set Artist or Album here so that the same code could work for any object that is a child of iPodLibraryGroup?

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  • How do I insert this subclass into my code?

    - by BamsBamx
    This is a very noob question so I hope you can help me with this... This is my built code: public class PantallaOpciones extends PreferenceActivity { private SharedPreferences preferences; @Override public void onCreate(Bundle savedInstanceState) { preferences = PreferenceManager.getDefaultSharedPreferences(this); findPreference("speechkeycode").setOnPreferenceClickListener(keycodedialog); Preference.OnPreferenceClickListener keycodedialog = new Preference.OnPreferenceClickListener(){ public boolean onPreferenceClick(Preference preference){ keycodedialog(); return false; }}; } private void keycodedialog(){ final Dialog dialog = new Dialog(this); dialog.setContentView(R.layout.keycodedialog); dialog.setTitle("Speech keycode"); final TextView keypresstext = (TextView) findViewById(R.id.keypresstext); Button savekeycode = (Button) dialog.findViewById(R.id.btnsavekeycode); savekeycode.setOnClickListener(new OnClickListener() { public void onClick(View v) { dialog.dismiss(); } }); Button resetkeycode = (Button) dialog.findViewById(R.id.btnresetvalue); resetkeycode.setOnClickListener(new OnClickListener() { public void onClick(View v) { dialog.dismiss(); } }); dialog.show(); } Okay, now I want to add this code to dialog: public boolean onKeyDown(int keyCode, KeyEvent event) { //SOME STUFF return super.onKeyDown(keyCode, event); } So I want to listen to a keypress when dialog is opened and show the keycode of hardware press by using textview.settext()... The question is: how do I insert public boolean onKeyDown into the dialog??? Thanks in advance!! :)

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  • factory class, wrong number of arguments being passed to subclass constructor

    - by Hugh Bothwell
    I was looking at Python: Exception in the separated module works wrong which uses a multi-purpose GnuLibError class to 'stand in' for a variety of different errors. Each sub-error has its own ID number and error format string. I figured it would be better written as a hierarchy of Exception classes, and set out to do so: class GNULibError(Exception): sub_exceptions = 0 # patched with dict of subclasses once subclasses are created err_num = 0 err_format = None def __new__(cls, *args): print("new {}".format(cls)) # DEBUG if len(args) and args[0] in GNULibError.sub_exceptions: print(" factory -> {} {}".format(GNULibError.sub_exceptions[args[0]], args[1:])) # DEBUG return super(GNULibError, cls).__new__(GNULibError.sub_exceptions[args[0]], *(args[1:])) else: print(" plain {} {}".format(cls, args)) # DEBUG return super(GNULibError, cls).__new__(cls, *args) def __init__(self, *args): cls = type(self) print("init {} {}".format(cls, args)) # DEBUG self.args = args if cls.err_format is None: self.message = str(args) else: self.message = "[GNU Error {}] ".format(cls.err_num) + cls.err_format.format(*args) def __str__(self): return self.message def __repr__(self): return '{}{}'.format(type(self).__name__, self.args) class GNULibError_Directory(GNULibError): err_num = 1 err_format = "destination directory does not exist: {}" class GNULibError_Config(GNULibError): err_num = 2 err_format = "configure file does not exist: {}" class GNULibError_Module(GNULibError): err_num = 3 err_format = "selected module does not exist: {}" class GNULibError_Cache(GNULibError): err_num = 4 err_format = "{} is expected to contain gl_M4_BASE({})" class GNULibError_Sourcebase(GNULibError): err_num = 5 err_format = "missing sourcebase argument: {}" class GNULibError_Docbase(GNULibError): err_num = 6 err_format = "missing docbase argument: {}" class GNULibError_Testbase(GNULibError): err_num = 7 err_format = "missing testsbase argument: {}" class GNULibError_Libname(GNULibError): err_num = 8 err_format = "missing libname argument: {}" # patch master class with subclass reference # (TO DO: auto-detect all available subclasses instead of hardcoding them) GNULibError.sub_exceptions = { 1: GNULibError_Directory, 2: GNULibError_Config, 3: GNULibError_Module, 4: GNULibError_Cache, 5: GNULibError_Sourcebase, 6: GNULibError_Docbase, 7: GNULibError_Testbase, 8: GNULibError_Libname } This starts out with GNULibError as a factory class - if you call it with an error number belonging to a recognized subclass, it returns an object belonging to that subclass, otherwise it returns itself as a default error type. Based on this code, the following should be exactly equivalent (but aren't): e = GNULibError(3, 'missing.lib') f = GNULibError_Module('missing.lib') print e # -> '[GNU Error 3] selected module does not exist: 3' print f # -> '[GNU Error 3] selected module does not exist: missing.lib' I added some strategic print statements, and the error seems to be in GNULibError.__new__: >>> e = GNULibError(3, 'missing.lib') new <class '__main__.GNULibError'> factory -> <class '__main__.GNULibError_Module'> ('missing.lib',) # good... init <class '__main__.GNULibError_Module'> (3, 'missing.lib') # NO! ^ why? I call the subclass constructor as subclass.__new__(*args[1:]) - this should drop the 3, the subclass type ID - and yet its __init__ is still getting the 3 anyway! How can I trim the argument list that gets passed to subclass.__init__?

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  • Java: Superclass to construct a subclass on certain conditions, possible?

    - by ramihope
    I have this condition public class A { public action() { System.out.println("Action done in A"); } } public class B extends A { public action() { System.out.println("Action done in B"); } } when I create an instance of B, the action will do just actions in B, as it overrides the action of the superclass. the problem is that in my project, the super class A is already used too many times, and I am looking for a way that under certain conditions, when i create an instance of A it makes a check and if it is true, replace itself with B. public class A { public A() { if ([condition]) { this = new B(); } } public action() { System.out.println("Action done in A"); } } A a = new A(); a.action(); // expect to see "Action done in B"... is this possible in some way?

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  • How to add a subclass to a viewcontroller in storyboard

    - by Ken Barlo
    Here's what I've created I created a view controller element (in storyboard) I created a new viewcontroller .h and .m file Here's my issue Can't seem to figure out how to get the content that I've added to the .m file to show up on the view controller element in the storyboard once the app is launched and the selection for that view controller element is made in the iPhone simulator. Although I am able to see content that is already added to a .m file on the home screen and activity screen when the selection is made in the iPhone simulator. Hope that makes sense, if not please ask and I'll be more than happy to provide more info.

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  • Subclassing an NSTextField

    - by Hooligancat
    Given all the complex things I seem to cover every day, this appears to be a "what the heck am I doing wrong that seems to simple?" scenario! I would like to subclass an NSTextField to change the background color and text color. For simplicity sake (and to help anyone who hasn't ever subclassed anything before), here is the example of my (simplified) subclass MyNSTextFieldSubclass... Step 1: Create the subclass file: First the header file @interface MyTextFieldSubclass : NSTextField { } @end And the method file @implementation MyTextFieldSubclass -(NSColor *)backgroundColor { return [NSColor redColor]; } -(NSColor *)textColor { return [NSColor yellowColor]; } @end Step 2: Drag an NSTextField to a window in Interface Builder, select the Identity tab in the inspector and select the class MyTextFieldSubclass Step 3: Save the IB file, build and run the application Problem When I run the build, the text field does not reflect the color subclassing. However, I know the subclass is being called because if I add the following method, it gets called on text changes. -(void)textDidChange:(NSNotification *)notification { NSLog(@"My text changed"); } So why does the color change not occur on the text fields? I know that I can set the color in IB, but for anyone who has dealt with a lot of UI elements that all need the same styling, subclassing makes life way, way easier. Ironically, I have never had to subclass an NSTextField before and this one has me stumped. As usual, any and all help very much appreciated. I'm sure it will turn out to be a "Doh!" moment - just cant see the wood for the trees right now (plus I'm exhausted from watching too much World Cup Football early in the morning which never helps).

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