I have two types edges in my supply chain model: demand_links and supply_links.
the default color is gray for all links. But I want to change the color of demand_links to red each time the attribute of the demand_link is changed (Note:the edge is the custom edge agent through edge creator). How to do this?
Below is my codes for simple test and it didn't work.
public class EdgeStyle2D extends DefaultStyleOGL2D {
#Override
public Color getColor(Object o){
// if (((CustomEdge) o).getCurrent_dl() == 1) {
// return Color.RED;
// }
// else {
// return Color.BLACK;
// }
if (o instanceof Distributor)
return Color.YELLOW;
return null;
}
}
I get the error when initialize.
Caused by: java.lang.ClassCastException: class supplyChainSystem.EdgeStyle2D cannot be cast to class repast.simphony.visualizationOGL2D.EdgeStyleOGL2D (supplyChainSystem.EdgeStyle2D and repast.simphony.visualizationOGL2D.EdgeStyleOGL2D are in unnamed module of loader repast.simphony.plugin.ExtendablePluginClassLoader #61af1510)
For styling links in this way, you should follow the example in the zombies.style.LinkStyle class within the Zombies_Demo model. Here's what the relevant parts of that class look like:
public class LinkStyle implements EdgeStyleOGL2D {
public Color getColor(RepastEdge<?> edge) {
BaseLink<?> link = (BaseLink<?>) edge;
return ReLogoSupport.lookupColor(link.getColor());
}
public int getLineWidth(RepastEdge<?> edge) {
return (int) (Math.abs(edge.getWeight()));
}
}
And you would use a class like this for the network (as opposed to agent) style.
Related
Trying to make a runner game. I don't want my character to fall off the edge of the map. How do I make the character always center of the path? I want to make so that my character is always center of the path as it is being instantiated and to never fall off the map.
public class GroundTile : MonoBehaviour
{
GroundSpawner groundSpawner;
// Start is called before the first frame update
private void Start()
{
groundSpawner = GameObject.FindObjectOfType<GroundSpawner>();
}
private void OnTriggerExit (Collider other)
{
groundSpawner.SpawnTile();
Destroy(gameObject, 2);
}
// Update is called once per frame
void Update()
{
}
}
public class GroundSpawner : MonoBehaviour
{
public GameObject groundTile;
Vector3 nextSpawnPoint;
// Start is called before the first frame update
public void SpawnTile()
{
GameObject temp = Instantiate(groundTile, nextSpawnPoint, Quaternion.identity);
nextSpawnPoint = temp.transform.GetChild(1).transform.position;
}
private void Start()
{
for (int i = 0; i < 10; i++)
{
SpawnTile();
}
}
}
I tried so many methods.
I am trying to clean and refactor my service code which currently looks like this-
public void generateBalance(Receipt receipt) {
if (receipt.getType().equals(X) && receipt.getRegion.equals(EMEA)) {
// do something to the receipt that's passed
} else if (receiptType.equals(Y)) {
// do something to the receipt
} else if (receipt.getRegion.equals(APAC) {
// call an external API and update the receipt
}....
...
// finally
dataStore.save(receipt);
Basically there's a bunch of conditionals that are in this main service which look for certain fields in the object that is being passed. Either it's the type or the region.
I was looking to use this design pattern- https://www.refactoring.com/catalog/replaceConditionalWithPolymorphism.html
However, I am not sure how this would work for a service class. Currently my REST handler calls this particular service. Also how can I do polymorphism for both the "receiptType" and "region"?
Is there a way I can just do all the updates to the receipt once in different services, then finally save the receipt at one location? (maybe a base class?) I am really confused on how to start. TIA!
If your classes should have the same behaviour, then it becomes pretty simple to use polymorpism. The pattern is called as Strategy. Let me show an example.
At first we need to use enum. If you do not have enum, then you can create a method which will return enum value based on your conditions:
if (receipt.getType().equals(X) && receipt.getRegion.equals(EMEA)) // other
// code is omitted for the brevity
So enum will look like this:
public enum ReceiptType
{
Emea, Y, Apac
}
Then we need an abstract class which will describe behaviour for derived classes:
public abstract class ActionReceipt
{
public abstract string Do();
}
And our derived classes will look this:
public class ActionReceiptEmea : ActionReceipt
{
public override string Do()
{
return "I am Emea";
}
}
public class ActionReceiptY : ActionReceipt
{
public override string Do()
{
return "I am Y";
}
}
public class ActionReceiptApac : ActionReceipt
{
public override string Do()
{
return "I am Apac";
}
}
Moreover, we need a factory which will create derived classes based on enum. So we can use Factory pattern with a slight modification:
public class ActionReceiptFactory
{
private Dictionary<ReceiptType, ActionReceipt> _actionReceiptByType =
new Dictionary<ReceiptType, ActionReceipt>
{
{
ReceiptType.Apac, new ActionReceiptApac()
},
{
ReceiptType.Emea, new ActionReceiptEmea()
},
{
ReceiptType.Y, new ActionReceiptY()
}
};
public ActionReceipt GetInstanceByReceiptType(ReceiptType receiptType) =>
_actionReceiptByType[receiptType];
}
And then polymorpism in action will look like this:
void DoSomething(ReceiptType receiptType)
{
ActionReceiptFactory actionReceiptFactory = new ActionReceiptFactory();
ActionReceipt receipt =
actionReceiptFactory.GetInstanceByReceiptType(receiptType);
string someDoing = receipt.Do(); // Output: "I am Emea"
}
UPDATE:
You can create some helper method which will return enum value based on
your logic of region and receiptType:
public class ReceiptTypeHelper
{
public ReceiptType Get(ActionReceipt actionReceipt)
{
if (actionReceipt.GetType().Equals("Emea"))
return ReceiptType.Emea;
else if (actionReceipt.GetType().Equals("Y"))
return ReceiptType.Y;
return ReceiptType.Apac;
}
}
and you can call it like this:
void DoSomething()
{
ReceiptTypeHelper receiptTypeHelper = new ReceiptTypeHelper();
ReceiptType receiptType = receiptTypeHelper
.Get(new ActionReceiptEmea());
ActionReceiptFactory actionReceiptFactory = new
ActionReceiptFactory();
ActionReceipt receipt =
actionReceiptFactory.GetInstanceByReceiptType(receiptType);
string someDoing = receipt.Do(); // Output: "I am Emea"
}
I'm still learning flutter/dart language tutorial.
This is my code. I create method that can return an object.How do i get data member from subclass via the method.
abstract class Shape{
get area;
}
class Circle implements Shape{
final radius;
Circle(this.radius);
get area=>pi*pow(radius,2);
}
class Square implements Shape{
final side;
Square(this.side);
get area=>pow(side,2);
}
Shape shapeFactory(String type){
if(type=='circle') return Circle(2);
if(type=='square') return Square(2);
throw 'Can\'t create $type.';
}
void main() {
var s=shapeFactory('square');
print(s.area);
print(s.side);
var c= shapeFactory('circle');
print(c.area);
print(c.radius);
}
as u can see,i can get area value,but i can't get radius or side values from class circle or class square which is subclass of class shape
This is because Shape doesn't have these properties. You need to cast to the specific type first or make shapeFactory generic.
void main() {
var s=shapeFactory('square') as Square;
print(s.area);
print(s.side);
var c= shapeFactory('circle') as Circle;
print(c.area);
print(c.radius);
}
or
T shapeFactory<T extends Shape>(String type){
if(type=='circle') return Circle(2) as T;
if(type=='square') return Square(2) as T;
throw 'Can\'t create $type.';
}
void main() {
var s=shapeFactory<Square>('square');
print(s.area);
print(s.side);
var c= shapeFactory<Circle>('circle');
print(c.area);
print(c.radius);
}
So i have a class that makes an array list for me and i need to access it in another class through a constructor but i don't know what to put into the constructor because all my methods in that class are just for manipulating that list. im either getting a null pointer exception or a out of bounds exception. ive tried just leaving the constructor empty but that dosent seem to help. thanks in advance. i would show you code but my professor is very strict on academic dishonesty so i cant sorry if that makes it hard.
You are confusing the main question, with a potential solution.
Main Question:
I have a class ArrayListOwnerClass with an enclosed arraylist property or field.
How should another class ArrayListFriendClass access that property.
Potential Solution:
Should I pass the arraylist from ArrayListOwnerClass to ArrayListFriendClass,
in the ArrayListFriendClass constructor ?
It depends on what the second class does with the arraylist.
Instead of passing the list thru the constructor, you may add functions to read or change, as public, the elements of the hidden internal arraylist.
Note: You did not specify a programming language. I'll use C#, altought Java, C++, or similar O.O.P. could be used, instead.
public class ArrayListOwnerClass
{
protected int F_Length;
protected ArrayList F_List;
public ArrayListOwnerClass(int ALength)
{
this.F_Length = ALength;
this.F_List = new ArrayList(ALength);
// ...
} // ArrayListOwnerClass(...)
public int Length()
{
return this.F_Length;
} // int Length(...)
public object getAt(int AIndex)
{
return this.F_List[AIndex];
} // object getAt(...)
public void setAt(int AIndex, object AValue)
{
this.F_List[AIndex] = AValue;
} // void setAt(...)
public void DoOtherStuff()
{
// ...
} // void DoOtherStuff(...)
// ...
} // class ArrayListOwnerClass
public class ArrayListFriendClass
{
public void UseArrayList(ArrayListOwnerClass AListOwner)
{
bool CanContinue =
(AListOwner != null) && (AListOwner.Length() > 0);
if (CanContinue)
{
int AItem = AListOwner.getAt(5);
DoSomethingWith(Item);
} // if (CanContinue)
} // void UseArrayList(...)
public void AlsoDoesOtherStuff()
{
// ...
} // void AlsoDoesOtherStuff(...)
// ...
} // class ArrayListFriendClass
Note, that I could use an indexed property.
How can I bind InitializerForXXX (non-generic implementation) to IInitializer<XXX> (generic interface) using Ninject Conventions so that requests for an IInitializer<T> resolve a non-generic implementation whose name starts with InitializerFor and end with typeof(T).Name like:
initializerFactory.CreateFor<Blue>(); //resolves InitializerOfBlue
initializerFactory.CreateFor<ShadeOfBlue>(); //resolves InitializerOfShadeOfBlue
where no non-abstract class directly implement IInitializer<T>, and some implementations inherit from other implementations:
InitializerForShadeOfBlue inherits from InitializerForBlue
InitializerForBlue inherits from abstract Initializer<Blue>
abstract Initializer<T> directly implements IInitializer<T>
I'm hoping I can use a .EndsWith(typeof(T).Name) for a given IInitializer<T> convention I can use, because there are literally hundreds of initializers in the ShadeOfxxx vein. If I have to map all of them, I'm better off finding a way to resolve with reflection at runtime.
Given the following:
UPDATE: bindings with custom binding generator (see my answer below for implementation)
void Bootstrap(IBindingRoot kernel)
{
kernel.Bind<IInitializerFactory>()
.To<InitializerFactory>()
.InSingletonScope();
kernel.Bind(scanner =>
scanner.FromThisAssembly().SelectAllClasses()
.WhichAreNotGeneric()
.InheritedFrom(typeof(IComplexContent))
.BindAllInterfaces());
kernel.Bind(scanner =>
scanner.FromThisAssembly().SelectAllClasses()
.WhichAreNotGeneric()
.InheritedFrom(typeof(IInitializer<>))
.BindWith<FirstTypeParameterNameMatchesEndOfBoundClassNameGenerator>());
}
main method
void Main(IEnumerable<string> values)
{
// setup bindings
var kernel = new StandardKernel();
Bootstrap(kernel);
IInitializerFactory initializerFactory =
kernel.Get<IInitializerFactory>();
IInitializer<ShadeOfBlueComplexContent> initializer =
initializerFactory.CreateFor<ShadeOfBlueComplexContent>();
initializer.Initialize(values);
}
initializer factory
interface IInitializerFactory
{
IInitializer<T> CreateFor<T>() where T : class, IComplexContent, new();
}
class InitializerFactory : IInitializerFactory
{
public IInitializer<T> CreateFor<T>() where T : class, IComplexContent, new()
{
return MagicallyGetInitializer<T>();
}
//behind the curtain, whirring noises are heard as 't' is resolved...
private static IInitializer<T> MagicallyGetInitializer<T>()
where T : class, IComplexContent, new()
{
IInitializer<T> i = null;
return i;
}
}
initializers
interface IInitializer<out T> where T : IComplexContent
{
T Initialize(IEnumerable<string> values);
}
abstract class Initializer<T> : IInitializer<T> where T : IComplexContent
{
public abstract T Initialize(IEnumerable<string> values);
}
class InitializerOfBlue : Initializer<Blue>
{
private readonly Blue _content;
public InitializerOfBlue(Blue content) {_content = content;}
public override Blue Initialize(IEnumerable<string> values)
{
_content.BlueSpecificProperty = values.ElementAt(0);
//... populate other blue-specific properties like this
return _content;
}
}
class InitializerOfShadeOfBlue : InitializerOfBlue
{
public InitializerOfShadeOfBlue(ShadeOfBlue content) : base(content){}
}
content models
interface IComplexContent
{
string OneBasicProperty { get; set; }
// other properties are specific to implementation
string UniqueOperation();
}
abstract class BaseComplexContent : IComplexContent
{
public string OneBasicProperty { get; set; }
public abstract string UniqueOperation();
}
class Blue : BaseComplexContent
{
// initializer sets this
public string PropertyForAllKindsOfBlue { get; set; }
// initializer doesn't interact with this
public override string UniqueOperation() {return "I'm plain.";}
}
class ShadeOfBlue : Blue
{
// initializer doesn't interact with this
public override string UniqueOperation() {return "I'm fabulous!";}
}
You are over specifying the class selection
kernel.Bind(scanner =>
scanner.FromThisAssembly().SelectAllClasses()
.WhichAreNotGeneric()
.InheritedFrom(typeof (IInitializer<>))
This is already enough. What you need to do though is to add a custom Binding Generator. That selects IInitializer<Blue> for InitializerForBlue and IInitializer<ShadeOfBlue> for InitializerForShadeOfBlue
https://github.com/ninject/ninject.extensions.conventions/wiki/Projecting-Services-to-Bind
BEGIN SOLUTION CANDIDATE - custom binding generator:
custom binding generator
Thanks for the advice, #RemoGloor and #RubenBartelink. I'm stumped though - the problem is that I wind up binding the IInitializer<Blue> to InitializerOfShadeOfBlue. I need to be able to somehow change the generic type argument from Blue to ShadeOfBlue in the IInitializer<Blue> binding candidate, since IInitializer<ShadeOfBlue> is what will be requested from the factory method at runtime.
Is there a way to modify the generic type argument list of the binding candidate? Or am I barking up the wrong implementation? Any edit suggestions to my OP or this answer are appreciated.
/// <summary>Creates bindings on open generic types where bound implementations'
/// names end with the name of the generic type argument</summary>
public class FirstTypeParameterNameMatchesEndOfBoundClassNameGenerator : IBindingGenerator
{
public IEnumerable<IBindingWhenInNamedWithOrOnSyntax<object>> CreateBindings(Type type, IBindingRoot bindingRoot)
{
if (type == null) throw new ArgumentNullException("type");
if (bindingRoot == null) throw new ArgumentNullException("bindingRoot");
// only consider concrete, non-abstract classes
if (type.IsInterface || type.IsAbstract) yield break;
var bindingType = GetBindingType(type);
if (bindingType != null)
yield return bindingRoot.Bind(bindingType).To(type);
// ARGH! bindingType == IInitializer`1[[Blue]] but I want
// IInitializer`1[[ShadeOfBlue]] for type == ShadeOfBlue
}
private static Type GetBindingType(Type type)
{
Type goodMatch = null;
foreach (var candidate in type.GetInterfaces())
{
// skip non-generic interfaces
if (!candidate.IsGenericType) continue;
// assumption: using argument in first position
var firstArg = candidate.GetGenericArguments().First();
if (!type.Name.EndsWith(firstArg.Name)) continue;
// IInitializer<XXX> matches InitializerOfXXX
goodMatch = candidate;
break;
}
if (goodMatch == null)
{
// if no match on interfaces, walk through the ancestor types
foreach (var candidate in type.GetAllAncestors())
{
goodMatch = GetBindingType(candidate);
if (goodMatch != null) break;
}
}
return goodMatch;
}
Type Extension helper
public static class TypeExtensions
{
// returns all ancestor types starting with the parent
public static IEnumerable<Type> GetAllAncestors(this Type type)
{
for (var current = type.BaseType; current != null; current = current.BaseType)
yield return current;
}
}
END SOLUTION CANDIDATE - custom binding generator