Search Results

Search found 12661 results on 507 pages for 'css inheritance'.

Page 29/507 | < Previous Page | 25 26 27 28 29 30 31 32 33 34 35 36  | Next Page >

• Fun with casting and inheritance

  - by Vaccano

  NOTE: This question is written in a C# like pseudo code, but I am really going to ask which languages have a solution. Please don't get hung up on syntax. Say I have two classes: class AngleLabel: CustomLabel { public bool Bold; // code to allow the label to be on an angle } class Label: CustomLabel { public bool Bold; // Code for a normal label // Maybe has code not in an AngleLabel (align for example). } They both decend from this class: class CustomLabel: Control { protected bool Bold; } The bold field is exposed as public in the descended classes. No interfaces are available on the classes. Now, I have a method that I want to beable to pass in a CustomLabel and set the Bold property. Can this be done without having to 1) find out what the real class of the object is and 2) cast to that object and then 3) make seperate code for each variable of each label type to set bold. Kind of like this: public void SetBold(customLabel: CustomLabel) { AngleLabel angleLabel; NormalLabel normalLabel; if (angleLabel is AngleLabel ) { angleLabel= customLabel as AngleLabel angleLabel.Bold = true; } if (label is Label) { normalLabel = customLabel as Label normalLabel .Bold = true; } } It would be nice to maybe make one cast and and then set bold on one variable. What I was musing about was to make a fourth class that just exposes the bold variable and cast my custom label to that class. Would that work? If so, which languages would it work for? (This example is drawn from an old version of Delphi (Delphi 5)). I don't know if it would work for that language, (I still need to try it out) but I am curious if it would work for C++, C# or Java. If not, any ideas on what would work? (Remember no interfaces are provided and I can not modify the classes.) Any one have a guess?

  Read the article

• Iterator blocks and inheritance.

  - by Dave Van den Eynde

  Given a base class with the following interface: public class Base { public virtual IEnumerable<string> GetListOfStuff() { yield return "First"; yield return "Second"; yield return "Third"; } } I want to make a derived class that overrides the method, and adds its own stuff, like so: public class Derived : Base { public override IEnumerable<string> GetListOfStuff() { foreach (string s in base.GetListOfStuff()) { yield return s; } yield return "Fourth"; yield return "Fifth"; } } However, I'm greeted with a warning that "access to a member through a base keyword from an iterator cannot be verified". What's the accepted solution to this problem then?

  Read the article

• A problem regarding dll inheritance

  - by Adam

  Hello all I have created a dll that will be used by multiple applications, and have created an installer package that installs it to the program files, as well as adds it to the Global Assembly Cache. The dll itself uses log4net, and requires a xml file for the logging definitions. Therefore when the installer is run, the following files get copied to the install directory within program files: The main dll that I developed - The Log4Net.dll - the Log4Net.xml file I am now experiencing a problem. I have created a test console application for experimentation. I have added my dll as a reference, and set the 'local copy' flag to false. When I compile the test console exe however, I noticed that it has copied the log4net.dll and log4net.xml files to the bin directory. And when running the test console, it appears that it will only work if the log4net.dll is in the same directory as the exe. This is dispite the fact that the test console application does not use log4net, only the dll that was added as a reference does. Is there some way to have it so that the log4net.dll & xml files used will be the ones that were installed to the program files, rather than any application needed to copy over local copies? The applications that will be using my dll will not be using log4net, only the dll that they are referencing uses it. Many thanks

  Read the article

• inheritance problem OOP extend

  - by hsmit

  If a Father is a Parent and a Parent is a Person and a Person has a Father I create the following: class Person{ Father father; } class Parent extends Person{} class Father extends Parent{} Instances: Person p1 = new Person(); Person p2 = new Person(); p1.father = p2; //father is of the type Father This doesn't work... Now try casting:: Person p1 = new Person(); Person p2 = new Person(); p1.father = (Father)p2; This doesn't work either. What does work for this case?

  Read the article

• Inheritance in XML Schema definition (XSD) for Java objects

  - by bguiz

  Hi, I need to create an XML schema definition (XSD) that describes Java objects. I was wondering how to do this when the objects in question inherit from a common base class with a type parameter. public abstract class Rule<T> { ... } public abstract class TimeRule extends Rule<XTime> { ... } public abstract class LocationRule extends Rule<Location> { ... } public abstract class IntRule extends Rule<Integer> { ... } .... (where XTime and Location are custom classes define elsewhere) How would I go about constructing an XSD that such that I can have XML nodes that represent each of the subclasses of Rule<T> - without the XSD for each of them repeating their common contents? Thank you!

  Read the article

• Using CSS how do you move text down when a floated image is above a certain width?

  - by Peter Kelley

  I have a text block with an image floated left. The images can be of variable width. If the image is say greater than 2/3 the width of the block I want the text to drop down below the image but if not I want it beside the image. All of this is in Drupal if that matters.

  Read the article

• C#.NET Generic Methods and Inheritance.

  - by ealgestorm

  Is it possible to do the following with generics in C#.NET public abstract class A { public abstract T MethodB<T>(string s); } public class C: A { public override DateTime MethodB(string s) { } } i.e. have a generic method in a base class and then use a specific type for that method in a sub class.

  Read the article

• how can I change top-margin the right way if multiple css class assigned?

  - by Radek

  I assigned these classes menu second_menu menu_about_author to ul so the html code looks like <ul class="menu second_menu menu_about_author"> I wanted this ul to have the same properties like menu and second_menu and then I wanted to move the menu_about_author little bit down. I did so by .menu_about_author { margin-top:40px; } but it didn't work any idea why the margin-top:40px; is crossed? the link to the image is [1]: http://img153.imageshack.us/img153/882/58daeef0c3c846e4a8d6321.png

  Read the article

• QMap inheritance with QMapIterator

  - by gregseth

  Hi, I made a personnal class which inherits QMap: class CfgMgr : public QMap<QString, CfgSet*> {...} I'm trying to iterate over all its elements like that: CfgMgr* m_pDefaults = new CfgMgr; // .../... QMapIterator<QString, CfgSet*> ics(*m_pDefaults); while (ics.hasNext()) { // doing my stuff } And I get the compile error: Can't convert parameter 1 from 'CfgMgr' to 'const QMap< Key,T &' with [ Key=QString, T=CfgSet * ] I tried with a dynamic_cast: QMapIterator<QString, CfgSet*> ics( *dynamic_cast< QMap<QString,CfgSet*>* >(m_pDefaults) ); it compiles, but always returns NULL. What's wrong? How can I solve this?

  Read the article

• C++ Storing variables and inheritance

  - by Kaa

  Hello Everyone, Here is my situation: I have an event driven system, where all my handlers are derived from IHandler class, and implement an onEvent(const Event &event) method. Now, Event is a base class for all events and contains only the enumerated event type. All actual events are derived from it, including the EventKey event, which has 2 fields: (uchar) keyCode and (bool)isDown. Here's the interesting part: I generate an EventKey event using the following syntax: Event evt = EventKey(15, true); and I ship it to the handlers: EventDispatch::sendEvent(evt); // void EventDispatch::sendEvent(const Event &event); (EventDispatch contains a linked list of IHandlers and calls their onEvent(const Event &event) method with the parameter containing the sent event. Now the actual question: Say I want my handlers to poll the events in a queue of type Event, how do I do that? x Dynamic pointers with reference counting sound like too big of a solution. x Making copies is more difficult than it sounds, since I'm only receiving a reference to a base type, therefore each time I would need to check the type of event, upcast to EventKey and then make a copy to store in a queue. Sounds like the only solution - but is unpleasant since I would need to know every single type of event and would have to check that for every event received - sounds like a bad plan. x I could allocate the events dynamically and then send around pointers to those events, enqueue them in the array if wanted - but other than having reference counting - how would I be able to keep track of that memory? Do you know any way to implement a very light reference counter that wouldn't interfere with the user? What do you think would be a good solution to this design? I thank everyone in advance for your time. Sincerely, Kaa

  Read the article

• Problem with inheritance and List<>

  - by Jagd

  I have an abstract class called Grouping. I have a subclass called GroupingNNA. public class GroupingNNA : Grouping { // blah blah blah } I have a List that contains items of type GroupingNNA, but is actually declared to contain items of type Grouping. List<Grouping> lstGroupings = new List<Grouping>(); lstGroupings.Add( new GroupingNNA { fName = "Joe" }); lstGroupings.Add( new GroupingNNA { fName = "Jane" }); The Problem: The following LINQ query blows up on me because of the fact that lstGroupings is declared as List< Grouping and fName is a property of GroupingNNA, not Grouping. var results = from g in lstGroupings where r.fName == "Jane" select r; Oh, and this is a compiler error, not a runtime error. Thanks in advance for any help on this one! More Info: Here is the actual method that won't compile. The OfType() fixed the LINQ query, but the compiler doesn't like the fact that I'm trying to return the anonymous type as a List< Grouping. private List<Grouping> ApplyFilterSens(List<Grouping> lstGroupings, string fSens) { // This works now! Thanks @Lasse var filtered = from r in lstGroupings.OfType<GroupingNNA>() where r.QASensitivity == fSens select r; if (filtered != null) { **// Compiler doesn't like this now** return filtered.ToList<Grouping>(); } else return new List<Grouping>(); }

  Read the article

• C++ function-pointer and inheritance

  - by pingvinus

  In parent class I have function, that operates under an array of functions, declared in child-class, number of functions for every child-class may vary. But since every function uses some object-variables, I can't declare them as static. I've try to do something like this: class A { public: typedef int (A::*func)(); func * fs; void f() { /*call functions from this->fs*/ } }; class B : public A { public: int smth; B(int smth) { this->smth = smth; this->fs = new func[1]; fs[0] = &B::f; } int f() { return smth + 1; } }; But, obviously it doesn't work. Any suggestions?

  Read the article

• C++ Multiple Inheritance Question

  - by John

  The scenario generating this is quite complex so I'll strip out a few pieces and give an accurate representation of the classes involved. /* This is inherited using SI by many classes, as normal */ class IBase { virtual string toString()=0; }; /* Base2 can't inherit IBase due to other methods on IBase which aren't appropriate */ class Base2 { string toString() { ... } }; /* a special class, is this valid? */ class Class1 : public IBase, public Base2 { }; So, is this valid? Will there be conflicts on the toString? Or can Class1 use Base2::toString to satisfy IBase? Like I say there are lots of other things not shown, so suggestions for major design changes on this example are probably not that helpful... though any general suggestions/advice are welcome.

  Read the article

• Inheritance of TCollectionItem

  - by JamesB

  I'm planning to have collection of items stored in a TCollection. Each item will derive from TBaseItem which in turn derives from TCollectionItem, With this in mind the Collection will return TBaseItem when an item is requested. Now each TBaseItem will have a Calculate function, in the the TBaseItem this will just return an internal variable, but in each of the derivations of TBaseItem the Calculate function requires a different set of parameters. The Collection will have a Calculate All function which iterates through the collection items and calls each Calculate function, obviously it would need to pass the correct parameters to each function I can think of three ways of doing this: Create a virtual/abstract method for each calculate function in the base class and override it in the derrived class, This would mean no type casting was required when using the object but it would also mean I have to create lots of virtual methods and have a large if...else statement detecting the type and calling the correct "calculate" method, it also means that calling the calculate method is prone to error as you would have to know when writing the code which one to call for which type with the correct parameters to avoid an Error/EAbstractError. Create a record structure with all the possible parameters in and use this as the parameter for the "calculate" function. This has the added benefit of passing this to the "calculate all" function as it can contain all the parameters required and avoid a potentially very long parameter list. Just type casting the TBaseItem to access the correct calculate method. This would tidy up the TBaseItem quite alot compared to the first method. What would be the best way to handle this collection?

  Read the article

• Inheritance of jQuery's prototype partially fails

  - by user1065745

  I want to use Coffeescript to create an UIObject class. This class should inherit from jQuery, so that instances of UIObject can be used as if they where created with jQuery. class UIObject isObject: (val) -> typeof val is "object" constructor: (tag, attributes) -> @merge jQuery(tag, attributes), this @UIObjectProperties = {} merge: (source, destination) -> for key of source if destination[key] is undefined destination[key] = source[key] else if @isObject(source[key]) @merge(source[key], destination[key]) return It partially works. Consider the Foobar class below: class Foobar extends UIObject constructor: -> super("<h1/>", html: "Foobar") $("body").append(new Foobar) works fine. BUT: (new Foobar).appendTo("body") places the tag, but also raises RangeError: Maximum call stack size exceeded. Was it just a bad idea to inherit from jQuery? Or is there a solurion? For those who don't know CoffeeScript, the JavaScript source is: var Foobar, UIObject; var __hasProp = Object.prototype.hasOwnProperty, __extends = function(child, parent) { for (var key in parent) { if (__hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor; child.__super__ = parent.prototype; return child; }; UIObject = (function () { UIObject.prototype.isObject = function (val) { return typeof val === "object"; }; function UIObject(tag, attributes) { this.merge(jQuery(tag, attributes), this); this.UIObjectProperties = {}; } UIObject.prototype.merge = function (source, destination) { var key; for (key in source) { if (destination[key] === void 0) { destination[key] = source[key]; } else if (this.isObject(source[key])) { this.merge(source[key], destination[key]); } } }; return UIObject; })(); Foobar = (function () { __extends(Foobar, UIObject); function Foobar() { Foobar.__super__.constructor.call(this, "<h1/>", { html: "Foobar" }); } return Foobar; })();

  Read the article

• C++: inheritance problem

  - by Helltone

  It's quite hard to explain what I'm trying to do, I'll try: Imagine a base class A which contains some variables, and a set of classes deriving from A which all implement some method bool test() that operates on the variables inherited from A. class A { protected: int somevar; // ... }; class B : public A { public: bool test() { return (somevar == 42); } }; class C : public A { public: bool test() { return (somevar > 23); } }; // ... more classes deriving from A Now I have an instance of class A and I have set the value of somevar. int main(int, char* []) { A a; a.somevar = 42; Now, I need some kind of container that allows me to iterate over the elements i of this container, calling i::test() in the context of a... that is: std::vector<...> vec; // push B and C into vec, this is pseudo-code vec.push_back(&B); vec.push_back(&C); bool ret = true; for(i = vec.begin(); i != vec.end(); ++i) { // call B::test(), C::test(), setting *this to a ret &= ( a .* (&(*i)::test) )(); } return ret; } How can I do this? I've tried two methods: forcing a cast from B::* to A::*, adapting a pointer to call a method of a type on an object of a different type (works, but seems to be bad); using std::bind + the solution above, ugly hack; changing the signature of bool test() so that it takes an argument of type const A& instead of inheriting from A, I don't really like this solution because somevar must be public.

  Read the article

• Use multiple inheritance to discriminate useage roles?

  - by Arne

  Hi fellows, it's my flight simulation application again. I am leaving the mere prototyping phase now and start fleshing out the software design now. At least I try.. Each of the aircraft in the simulation have got a flight plan associated to them, the exact nature of which is of no interest for this question. Sufficient to say that the operator way edit the flight plan while the simulation is running. The aircraft model most of the time only needs to read-acess the flight plan object which at first thought calls for simply passing a const reference. But ocassionally the aircraft will need to call AdvanceActiveWayPoint() to indicate a way point has been reached. This will affect the Iterator returned by function ActiveWayPoint(). This implies that the aircraft model indeed needs a non-const reference which in turn would also expose functions like AppendWayPoint() to the aircraft model. I would like to avoid this because I would like to enforce the useage rule described above at compile time. Note that class WayPointIter is equivalent to a STL const iterator, that is the way point can not be mutated by the iterator. class FlightPlan { public: void AppendWayPoint(const WayPointIter& at, WayPoint new_wp); void ReplaceWayPoint(const WayPointIter& ar, WayPoint new_wp); void RemoveWayPoint(WayPointIter at); (...) WayPointIter First() const; WayPointIter Last() const; WayPointIter Active() const; void AdvanceActiveWayPoint() const; (...) }; My idea to overcome the issue is this: define an abstract interface class for each usage role and inherit FlightPlan from both. Each user then only gets passed a reference of the appropriate useage role. class IFlightPlanActiveWayPoint { public: WayPointIter Active() const =0; void AdvanceActiveWayPoint() const =0; }; class IFlightPlanEditable { public: void AppendWayPoint(const WayPointIter& at, WayPoint new_wp); void ReplaceWayPoint(const WayPointIter& ar, WayPoint new_wp); void RemoveWayPoint(WayPointIter at); (...) }; Thus the declaration of FlightPlan would only need to be changed to: class FlightPlan : public IFlightPlanActiveWayPoint, IFlightPlanEditable { (...) }; What do you think? Are there any cavecats I might be missing? Is this design clear or should I come up with somethink different for the sake of clarity? Alternatively I could also define a special ActiveWayPoint class which would contain the function AdvanceActiveWayPoint() but feel that this might be unnecessary. Thanks in advance!

  Read the article

• c++ inheritance

  - by Meloun

  Hi, i am trouble with this.. Is there some solution or i have to keep exactly class types? //header file Class Car { public: Car(); virtual ~Car(); }; class Bmw:Car { public: Bmw(); virtual ~Bmw(); }; void Start(Car& mycar) {}; //cpp file Car::Car(){} Car::~Car() {} Bmw::Bmw() :Car::Car(){} Bmw::~Bmw() {} int main() { Car myCar; Bmw myBmw; Start(myCar); //works Start(myBmw); //!! doesnt work return 0; }

  Read the article

• Java Inheritance doubt in parameterised collection

  - by Gala101

  It's obvious that a parent class's object can hold a reference to a child, but does this not hold true in case of parameterised collection ?? eg: Car class is parent of Sedan So public void doSomething(Car c){ ... } public void caller(){ Sedan s = new Sedan(); doSomething(s); } is obviously valid But public void doSomething(Collection<Car> c){ ... } public void caller(){ Collection<Sedan> s = new ArrayList<Sedan>(); doSomething(s); } Fails to compile Can someone please point out why? and also, how to implement such a scenario where a function needs to iterate through a Collection of parent objects, modifying only the fields present in parent class, using parent class methods, but the calling methods (say 3 different methods) pass the collection of three different subtypes.. Ofcourse it compiles fine if I do as below: public void doSomething(Collection<Car> c){ ... } public void caller(){ Collection s = new ArrayList<Sedan>(); doSomething(s); }

  Read the article

• Variables variable and inheritance

  - by Xack

  I made code like this: class Object { function __get($name){ if(isset($this->{$name})){ return $this->{$name}; } else { return null; } } function __set($name, $value){ $this->{$name} = $value; } } If I extend this class (I don't want to repeat this code every time), it says "Undefined variable". Is there any way to do it?

  Read the article

• Comparing objects and inheritance

  - by ereOn

  Hi, In my program I have the following class hierarchy: class Base // Base is an abstract class { }; class A : public Base { }; class B : public Base { }; I would like to do the following: foo(const Base& one, const Base& two) { if (one == two) { // Do something } else { // Do something else } } I have issues regarding the operator==() here. Of course comparing an instance A and an instance of B makes no sense but comparing two instances of Base should be possible. (You can't compare a Dog and a Cat however you can compare two Animals) I would like the following results: A == B = false A == A = true or false, depending on the effective value of the two instances B == B = true or false, depending on the effective value of the two instances My question is: is this a good design/idea ? Is this even possible ? What functions should I write/overload ? My apologies if the question is obviously stupid or easy, I have some serious fever right now and my thinking abilities are somewhat limited :/ Thank you.

  Read the article

• Constructors with inheritance in c++

  - by Crystal

  If you have 3 classes, with the parent class listed first shape- 2d shapes, 3d shapes - circle, sphere When you write your constructor for the circle class, would you ever just initialize the parent Shape object and then your current object, skipping the middle class. It seems to me you could have x,y coordinates for Shape and initialize those in the constructor, and initialize a radius in the circle or sphere class, but in 2d or 3d shape classes, I wouldn't know what to put in the constructor since it seems like it would be identical to shape. So is something like this valid Circle::Circle(int x, int y, int r) : Shape(x, y), r(r) {} I get a compile error of: illegal member initialization: 'Shape' is not a base or member So I wasn't sure if my code was legal or best practice even. Or if instead you'd have the middle class just do what the top level Shape class does TwoDimensionalShape::TwoDimensionalShape(int x, int y) : Shape (x, y) {} and then in the Circle class Circle::Circle(int x, int y, int r) : TwoDimensionalShape(x, y), r(r) {}

  Read the article

• CSS/Jquery How can I display a div directly under button?

  - by user342391

  I have a button that when hovered displays a div. How can I postion this div to appear directly under the button when displayed??? <script type="text/javascript"> $(document).ready(function(){ $(".plans").hover(function() { $("#planssubnav").show("slow"); }, function(){ $("#planssubnav").hide("slow"); }); }); </script> <a href="/plans" style="font-size:14px;" class="plans fg-button fg-button-icon-right ui-state-default ui-corner-all"><span class="ui-icon ui-icon-circle-triangle-s"></span>Plans</a> <div id="planssubnav" style="display:none"> <h1> content</h1> </div>

  Read the article

• How to map inheritance with property returned other inheritance?

  - by dario-g

  Hi I have abstract class Vehicle and two classes that derive from: Car and ForkLift. public abstract class Vehicle { public EngineBase Engine { get; set; } } public class Car : Vehicle { public GasEngine Engine { get; set; } } public class ForkLift : Vehicle { public ElectricEngine Engine { get; set; } } and Engine clasess: public abstract class Engine { } public class GasEngine : Engine { } public class ElectricEngine : Engine { } Engines are mapped with "table per class hierarchy". With Vehicles I want to use the same pattern. How to map Engine class and derived with that Engine property?

  Read the article

• Inheritance policy when designing the base class

  - by Xaqron

  I have a base class and a derived class both in design phase. The base class will remain one but many derived class will inherit from it. So it's very costly to make change to derived classes in the future and I'm looking for the best design to prevent this. In fact derived class only needs a few methods to override (if needed) but it's tempting to reveal more details to it. My question is about the policy which is extensible in future. Can I minimize the inherited methods/properties to derived class and reveal more in the next versions if needed without any change to derived classes ? Or I should reveal anything that maybe used by derived classes in the future and let them to choose if they need them or not ? Thanks

  Read the article

< Previous Page | 25 26 27 28 29 30 31 32 33 34 35 36  | Next Page >