Program Design Problem: Inner Class use verse interacting seperate classes?

i am designing a GUI based program that needs to have 2+ windows that interact with each other. In my original design there were just two windows: the World display, and the tile choser (this is for 2D map editing). Because there were only 2, I made them both inner classes of another class. The top level class's fields were how I got the two windows to interact.
Now I am adding more tile choser esque windows and it is getting very confusing and the amount of Fields is getting ridiculous and the whole thing isnt very OO.
I thought about splitting up the World Display window and the Tile Choser window into two different classes and just have multiple instances of the Tile Choser class for the additional windows.
The problem is the interaction. I could pass all of the variables that both classes require to constructers and set up lots and lots of get and set methods, but then that seems to destroy the whole idea of two classes. The whole project is getting really messy.
Any thoughts?
I know that was a jarbled explanation so just ask about any part that might be unclear

Create an object that represents the state being manipulated. The model.
Create methods to modify that data. Not getters/setters, but controllers. If it's a map, then maybe a method would be "addTown" or something. This represents the controller.
Create methods to render the data graphically. The views.
Pass this object to GUI widgets, or reference it from inner event handlers.

Similar Messages

Calling a method from another class while in a seperate class

Hello
I am currently TRYING to proramme a simple alarm clock program, The way it has had to be set out is that there are two classes one is called ClockDisplay which is just the clock and the one i have had to create is called AlarmDisplay
I am trying to write code so that when the String alarmdisplayString(this is located in the alarm class which i am typing this code) is the same as String displayString the system will print out something like "Beep wake up" So far i have this code but i cannot figue out what to put to reference the method from the ClockDisplay class while codingi n the AlarmDisplay class
if(alarmdisplayString = DONT KNOW WHAT TO PUT HERE) {
system.out.println ("DING WAKE UP");
Any help would be great!
Thanks

That makes sense i have put in this code
private void Alarmtone()
ClockDisplay displayString = new ClockDisplay();
if (alarmdisplayString == ClockDisplay.displayString){
system.out.println ("DING WAKE UP");
displayString is the method in the ClockDisplay Class
alarmdisplayString is the method in the AlarmDisplay class
I get the error message "non-static variable displayString cannot be referenced from a static context
Thanks for the help so far :D

Design for two interacting, extensible classes

Hi,
I have a design problem where I have two interacting classes that both need to be highly extensible. I'm pretty sure this not an uncommon problem but I can't really seem to find an appropriate pattern to implement it.
The problem comes from the field of reinforcement learning, where an Agent learns some task in an Environment by executing Actions based on the current State of the environment. The State has to be provided by the Environment, and the Action chosen by the Agent based on that State has to be executed on the Environment. I thus have an Environment interface (for multi-agent problems) like so:
public interface Environment {
     //execute given action for given agent (e.g., move the agent, let the agent pick up smth
        //in the env, etc), and return a reward
     public double executeAction( Action act, Agent a );
     //compute and return state of given agent (e.g., what the agent can currently see in the
       //environment)
     public State getState( Agent a );
}There can be many different types of environments, and many different types of actions. So I thought of having a callback method on the Action that the Environment calls in method executeAction, like:
public interface Action {
     //execute on the given environment for the given agent
     public void execute(Environment env, Agent a);
}In that case you could have the same environment (e.g., a world with blocks), and different actions (say move, push a block away, pick up a block, etc). Does this make any sense? It's a little like the Command pattern perhaps?
There are two things I'm worried about. One is that the Action would need to cast the received Environment to the right implementation, but I guess that's unavoidable. The other (actually two) is that the Environment implementation would need to expose the right methods for the action to be able to execute, plus I don't always want an Action to be able to do anything it wants with the environment (e.g. teleport the agent, remove all obstacles). On the other hand maybe I shouldn't worry about the latter since it's just meant to be a toolkit, so if people using it want to program actions to teleport the agent, that's their business.
Any suggestions/comments greatly appreciated.
Thanks
Matt

I am not a native english speaker, and I'm not sure I understand your description. Is the following pseudo-code a correct description of your design?No problem, me neither. Maybe that's why it was hard to understand :) Actually, an agent should by no means have direct access to the environment: it is only allowed to perceive things through the State object it receives. So the design is something like:
public interface Agent {
        //do a step: choose an action based on the current state, and learn from
        //the reward received after the last action.
     public Action doStep( State s, double reward );
public class Simulator {
        //do one simulation step
     public void doStep() {
          State s;
          Action act;
          for ( Agent a : agents ) {
                        //get the agent's state from the environment
               s = env.getState(a);
                        //let the agent choose an action based on that state (lastReward is stored in a Map, omitted)
               act = a.doStep(s, lastReward);
                        //execute action on the environment and store the reward for this agent
               lastReward = env.executeAction(act, a));
There are two things I'm worried about. One is that the Action would need to cast the received Environment to the right implementation, but I guess that's unavoidable.Why? Cant he environment interface define abstract "modifier" methods that make sense to all implementations?Not really. An environment can be anything: a world with objects that the agent has to collect/avoid (I chose that example because I thought it might be easy to visualise and understand). A Blackjack game in which the agent has to choose to get another card or stop. The stock market in which the agent has to make trading decisions. And so on.
And iff the actions are specific to some environment implementations, then each environment can implement executeAction his way, for example calling different Action methods. In this case the Action become merely a Visitor.Yes, I indeed looked at the Visitor pattern, but I think it's not flexible enough. The types of the environments / actions need to be known beforehand, and in my case they can be anything.
The other (actually two) is that the Environment implementation would need to expose the right methods for the action to be able to execute, plus I don't always want an Action to be able to do anything it wants with the environment (e.g. teleport the agent, remove all obstacles).Method executeAction should use only those methods exposed in interface Environment (which is the type of the env argument).
If the Action and Agent implementations need some different views of the environments, just define two different interfaces.Hmm, yes. The problem is that the Environment interface should pretty much only specify those methods that I listed. Those are the methods necessary for the reinforcement learning paradigm (basically as implemented in the Simulator). Adding additional, problem-specific methods to that interface would not make sense, because environments can be anything. But, perhaps I could do something like:
public interface BlockWorld {
     public boolean move(Block b);
     public Block getBlockAt(int x, int y);
public class SomeWorld implements Environment, BlockWorld {}
public class PushAction implements Action {
     @Override
     public void execute(Environment env, Agent a) {
                //unavoidable (?) cast
          BlockWorld world = (BlockWorld) env;
          //get the block that the agent is facing, and move it
          //as specified in the action
}So define an interface according to the methods the world wants to expose. The only concern is that the same world (with obstacles and what not) could be used in a lot of different contexts, and I guess it's not desirable to subclass it every time just to make it implement an additional interface because one wants to expose different methods. But maybe I can use the Adapter pattern for this?

Poker Engine Design Problem

Hello Brothers,
I am currently developing Texas Holdem Poker Game. I have designed some classes of this game. From which I have confusion abt two classes, PokerTable class and PokerEngine class.
- whether I make PokerEngine class as an inner class of PokerTable class or as a seperate class?

ok, thanks for your reply,
Ther PokerEngine class has members like Deck, Player list, pot list, rake, and it executes the GameModel. GameMode contains rules of the game like maximum players, pot limit, number of raises etc. PokerTable class has playerlist, statastics, sitIn(), sitOut() etc.
hitesh

Urgent !!!!!!!!!!!! regarding CREATE JAVA CLASS USING BFILE

We have Oracle 8.1.7 spatial database. We got to load some java classes into the database. We would like to make it as the java programs to be loaded from a client system into the oracle server. I am using CREATE DIRECTORY command to create a directory object (say suppose \\prav\loadjavaclasses\. Then using the CREATE OR REPLACE JAVA CLASS USING BFILE (object_name, 'CLASSNAME.CLASS'). This .class file is in the network identified by prav which in turn has a shared directory (full privileges) loadjavaclasses folder. Can you please help in this regard.
Please mail me to [email protected]
thanks in advance
SudhaSrikanthan
null

use loadjava

Object oriented design problem concerning abstract classes and interfaces

I have an abstract class (class A) that takes care of database connections. It cannot be made into an interface as other classes extend it and all these other classes require the functionality in the methods it has (i.e. I cannot make all the methods abstract and then make this class an interface).
I have a class that contains data (Customer class) that I will create from the data I extract from the database. This class will also be created by the User and submitted to the database portion of the program. The Customer class has functionality in its methods which is required by the rest of the program (i.e. I cannot make all the methods abstract and then make this class an interface).
I have a factory class (CustomerFactory) that extends the Customer class. This has been created to restrict access to the creation and manipulation of Customers.
I have a class (DatabaseQuery) that extends class A. But now that I have retrieved all of the information that comprises a Customer from the database, I cannot construct a Customer without making reference to UserFactory. But UserFactory is a class that I don't want the database portion of the program to know about.
What I would like to do is have my DatabaseQuery class extend both Customer class and A class. But they are both classes and Java won't allow that.
I can't make either of the two classes that I want to make parents of DatabaseQuery into interfaces... so what can I do other than just keep a reference to UserFactory in my DatabaseQuery class?
Thanks,
Tim

>
What I would like to do is have my DatabaseQuery class
extend both Customer class and A class. But they are
both classes and Java won't allow that.
I can't make either of the two classes that I want to
make parents of DatabaseQuery into interfaces... so
what can I do other than just keep a reference to
UserFactory in my DatabaseQuery class?Just a guess...
The description sounds a little vague but it sounds like the correct solution would be to refactor everything. The first clue is when I see "database connection" as an "abstract class". The only hierarchy that a database connection might exist in is in a connection pool and even that is probably shaky. It should never be part of data records, which is what your description sounds like.
That probably isn't what you want to hear.
The other solution, which is why refactoring is better (and which also makes it apparent why the original design is wrong) is to create an entire other hierarchy that mirrors your current data hierarchy and wraps it. So you now have "Customer", you will now have "Customer" and "DBCustomer". And all the code that currently uses "Customer" will have to start using DBCustomer. Actually it is easier than that since you can simply make the new class be "Customer" and rename the old class to "DBCustomer". Naturally that means the new class will have to have all of the functionality of the old class. Fortunately you can use the old class to do that. (But I would guess that isn't going to be easy.)

Classification System CA-CL: Problems / Dumps while using a new class type

Hi All,
You'd really make my day by helping me out w. hints or even a solution. Would reward points for your efforts...
The problem: in order to develop a class hierachy of product groups (in industry system, Rel. 6.40) I created a new class type (let's call it ZWG).
While doing so R/3 requsted me to provide info on the objects to assign to this class type as well as the transaction for displaying these objects. For Product Groups (material classes) this is object-table T023 and transaction WG24.
Furthermore the sys demands the implementation of a function module. This module's task is to check the existence of a given object as well as the locking and later unlocking in the process of classifying objects. Following SAP's naming convention I implemented and activated FM OBJECT_CHECK_T023.
After that I created a new class (FIRST_CLASS) of class-type ZWG.
I managed to assign exactly one (1) prod-grp to this class but afterwards I only receive dumps while using transactions CL20N, CL24N to assign objects.
The Message from ST22 says:
Assignment error: Overwriting a protected field.
Error in ABAP application program.
The current ABAP program "SAPLCLCV" had to be terminated because one of the
statements could not be executed.
This is probably due to an error in the ABAP program.
Do I have to debug throughout thís enormous amount of coding now? :-(((
Hope someone get's my "message in a bottle"
Best Regards
Udo

Yatin please see attached for warning.I am trying to create Z class using 001

Help: Factory Class using Inner Class and Private Constructor?

The situation is as follows:
I want a GamesCollection class that instantiates Game objects by looking up the information needed from a database. I would like to use Game outside of GamesCollection, but only have it instantiated by GamesCollection to ensure the game actually exist. Each Game object is linked to a database record. If a Game object exist, it must also exist in the database. Game objects can never be removed from the database.
I thought about making the Game object an inner class of GamesCollection, but this means that Game class constructor is still visible outside. So what if I made Game constructor private? Well, now I can't create Game objects without a static method inside Game class (static Object factory).
Basically what I need is a constructor for the inner Game class accessible to GamesCollection, but not to the rest of the world (including packages). Is there a way to do this?

leesiulung wrote:
As a second look, I was initially confused about your first implementation, but it now makes more sense.
Let me make sure I understand this:
- the interface is needed to make the class accessible outside the outer classBetter: it is necessary to have a type that is accessible outside of GameCollection -- what else could be the return type of instance?
- the instance() method is the object factory
- the private modifier for the inner class is to prevent outside classes to instantiate this objectRight.
However, is a private inner class accessible in the outer class? Try it and see.
How does this affect private/public modifiers on inner classes?Take about five minutes and write a few tests. That should answer any questions you may have.
How do instantiate a GameImpl object? This basically goes back to the first question.Filling out the initial solution:
public interface Game {
    String method();
public class GameCollection {
    private static class GameImpl implements Game {
        public String method() {
            return "GameImpl";
    public Game instance() {
        return new GameImpl();
    public static void main(String[] args) {
        GameCollection app = new GameCollection();
        Game game = app.instance();
        System.out.println(game.method());
}Even if you were not interested in controlling game creation, defining interfaces for key concepts like Game is always going to be a good idea. Consider how you will write testing code, for example. How will you mock Game?

Hello, I have created a distribution kit for my program.The problem is that the when the program is installed onto another computer, it fails to communicate with field point (Using FP-AO-200 and FP-AO-1000). Help is greatly appreciated, Thanks faen9901

Hi Everyone,
I have a program that sends information(analog output) to lab windows cvi in the form of a text file or user input.
The program runs on the computers that I have the field point explorer and lab windows cvi installed on. In order to run the program without always installing labwindows/cvi and field point; I wanted to create an executable file that could be load on another computer.
I used the create distribution kit part of labwindows/cvi to do this.After creating the distribution kit, I then installed it
to another computer.
My user interface appears on the screen, when the user clicks on the exe. file, but no data is sent to the field point module. I know that the data is being read from the user and textfile because in it appears in the uir.
The following are some details about the problem:
1. On another computer without labwindows/cvi and field point explorer not installed - no data is sent to field point module
I know this because a current is being read on the current meter connected to field point module.
My questions are the following:
1. What are the possible reasons for the data not being sent to the field point module?
2. Do I still need to create an iak. (Installing Field point Explorer) file stored on any new computer that I install my created distribution kit file too?
Thankyou very much for any help that you can provide. I greatly appreciate it.
Faen9901

Re: Hello, I have created a distribution kit for my program.The problem is that the when the program is installed onto another computer, it fails to communicate with field point (Using FP-AO-200 and FP-AO-1000). Help is greatly appreciated, Thanks faen9901Faen9901,
1) If you do not install FieldPoint Explorer, the FieldPoint Server is not installed so there is nothing on the target computer that knows how to talk to the FieldPoint system.
2) Yes, you need an IAK file on the target computer. Assuming the settings (i.e. com port#) are identical you can simply include the iak file as part of the distribution.
3) You also need to include as part of your installer the file "fplwmgr.dll". If this file is not installed, your program will not be able to access the FieldPoint Server. Alternatively, this file is installed automatically if FieldPoint Explorer detects LabWindows/CVI or Measurement Studio Development versions on the target computer or if you choose to do a custom FieldPoint Explorer installation and
choose to provide LabWindows/CVI support.
Regards,
Aaron

We are currently looking for a way to link images to a design file within programs like InDesign and Illustrator using an HTML link instead of a local file. We are hosting our images in SharePoint and need the design file to retain it's links, no matter

We are currently looking for a way to link images to a design file within programs like InDesign and Illustrator using an HTML link instead of a local file. We are hosting our images in SharePoint and need the design file to retain it's links, no matter who on our network opens the design file.

The Cloud forum is not about using individual programs
The Cloud forum is about the Cloud as a delivery & install process
If you will start at the Forums Index https://forums.adobe.com/welcome
You will be able to select a forum for the specific Adobe product(s) you use
Click the "down arrow" symbol on the right (where it says All communities) to open the drop down list and scroll

Display problems in IE, using Netlace Designs approach

Display problems in IE, using Netlace Designs approach
Could someone please look at
www.tudo.co.uk/testing/magnification/
I am trying to adjust some css code taken from Netlace
Design's website
for my purposes. The purpose is to enlarge an image on
'hover' and to
enlarge some text on 'hover'.
What I have done works all right in Mozilla/Seamonkey.
However, in IE,
the 'text enlargement' does not work at all
and when I am enlarging the image there is ***in IE*** a
large grey
surplus area at the bottom, which looks like a background
area which has
turned out to have too much height. I want to get rid of that
superfluous grey area.
How can I make sure it works in BOTH Mozilla and in IE?
Thanks for your help.
Adrian

Hi ijmari,
I checked out that page and don't see any Spry menubar in it.
I'm assuming you've reverted back or removed it.
If you still need/want help, please post the URL to the page
that uses the menubar and demonstates the problem.
--== Kin ==--

I am trying to cut and paste from a program, IEP DIRECT, and normally on my PC I have no problems; however, when using my MAC the formatting gets all mixed up

i am trying to cut and paste from a program, IEP DIRECT, and normally on my PC I have no problems; however, when using my MAC the formatting gets all mixed up

If you refer to this
https://www.iepdirect.com/iepdotnet/hub/index.html
then they have an issue with mac version.
At a first glance, their website is optimized for Windows only, it displays badly in Safari, perhaps it would be better in Firefox or other browser.

How to access private method of an inner class using reflection.

Can somebody tell me that how can i access private method of an inner class using reflection.
There is a scenario like
class A
class B
private fun() {
now i want to use method fun() of an inner class inside third class i.e "class c".
Can i use reflection in someway to access this private method fun() in class c.

I suppose for unit tests, there could be cases when you need to access private methods that you don't want your real code to access.
Reflection with inner classes can be tricky. I tried getting the constructor, but it kept failing until I saw that even though the default constructor is a no-arg, for inner classes that aren't static, apparently the constructor for the inner class itself takes an instance of the outer class as a param.
So here's what it looks like:
        //list of inner classes, if any
        Class[] classlist = A.class.getDeclaredClasses();
        A outer = new A();
        try {
            for (int i =0; i < classlist.length; i++){
                if (! classlist.getSimpleName().equals("B")){
//skip other classes
continue;
//this is what I mention above.
Constructor constr = classlist[i].getDeclaredConstructor(A.class);
constr.setAccessible(true);
Object inner = constr.newInstance(outer);
Method meth = classlist[i].getDeclaredMethod("testMethod");
meth.setAccessible(true);
//the actual method call
meth.invoke(inner);
} catch (Exception e) {
throw new RuntimeException(e);
Good luck, and if you find yourself relying on this too much, it might mean a code redesign.

Need sample program OO abap alv using hotspot( interactive report)

need sample program on Object Oriented program using alv interactive report.

*& Report Z8VM_N_PO_PRICING_CONDITION *
REPORT Z8VM_N_PO_PRICING_CONDITION NO STANDARD PAGE HEADING
MESSAGE-ID Z8VM.
vivekanand meghmala
trial assignment
po with pricing condition interactive report with checkbox
data declaration
TYPES : BEGIN OF STRUCT_EKKO, "po header
BUKRS LIKE T001-BUKRS,
EBELN LIKE EKKO-EBELN,
BSART LIKE EKKO-BSART,
BEDAT LIKE EKKO-BEDAT,
EKORG LIKE EKKO-EKORG,
WAERS LIKE EKKO-WAERS,
LIFNR LIKE EKKO-LIFNR,
KNUMV LIKE EKKO-KNUMV,
END OF STRUCT_EKKO.
TYPES : BEGIN OF STRUCT_EKPO, "po details
EBELN LIKE EKPO-EBELN,
EBELP LIKE EKPO-EBELP,
MATNR LIKE EKPO-MATNR,
END OF STRUCT_EKPO.
TYPES : BEGIN OF STRUCT_KONV,
KNUMV LIKE KONV-KNUMV,
KPOSN LIKE KONV-KPOSN,
KSCHL LIKE KONV-KSCHL,
KAWRT LIKE KONV-KAWRT,
KBETR LIKE KONV-KBETR,
END OF STRUCT_KONV.
DATA : IT_EKKO TYPE STANDARD TABLE OF STRUCT_EKKO WITH HEADER LINE.
DATA : IT_EKPO TYPE STANDARD TABLE OF STRUCT_EKPO WITH HEADER LINE.
DATA : IT_KONV TYPE STANDARD TABLE OF STRUCT_KONV WITH HEADER LINE.
PARAMETERS : T_BUKRS LIKE EKKO-BUKRS .
SELECT-OPTIONS : S_BEDAT FOR IT_EKKO-BEDAT.
SELECT-OPTIONS : S_EKORG FOR IT_EKKO-EKORG.
validations
AT SELECTION-SCREEN.
IF T_BUKRS = ' '.
MESSAGE E009.
ENDIF.
SELECT BUKRS FROM T001
INTO CORRESPONDING FIELDS OF IT_EKKO
WHERE BUKRS = T_BUKRS.
EXIT.
ENDSELECT.
IF SY-SUBRC 0.
MESSAGE E001.
ENDIF.
logic
START-OF-SELECTION.
SELECT BUKRS
EBELN
BSART
BEDAT
EKORG
WAERS
LIFNR
KNUMV FROM EKKO INTO CORRESPONDING FIELDS OF TABLE IT_EKKO
WHERE BUKRS = T_BUKRS
AND BEDAT IN S_BEDAT
AND EKORG IN S_EKORG.
SELECT EBELN
EBELP
MATNR FROM EKPO INTO CORRESPONDING FIELDS OF IT_EKPO
FOR ALL ENTRIES IN IT_EKKO WHERE EBELN = IT_EKKO-EBELN.
APPEND IT_EKPO.
ENDSELECT.
LOOP AT IT_EKPO.
SELECT KNUMV
KPOSN
KSCHL
KAWRT
KBETR FROM KONV INTO CORRESPONDING FIELDS OF IT_KONV
WHERE KPOSN = IT_EKPO-EBELP.
APPEND IT_KONV.
ENDSELECT.
ENDLOOP.
*data printing
LOOP AT IT_EKKO.
WRITE :/ IT_EKKO-BUKRS,IT_EKKO-EBELN,IT_EKKO-BSART,IT_EKKO-BEDAT,
IT_EKKO-EKORG,IT_EKKO-WAERS,IT_EKKO-LIFNR,IT_EKKO-KNUMV.
LOOP AT IT_EKPO WHERE EBELN = IT_EKKO-EBELN.
WRITE :/ IT_EKPO-EBELP,IT_EKPO-MATNR.
LOOP AT IT_KONV.
WHERE KPOSN = IT_EKPO-EBELN.
WRITE :/ IT_KONV-KNUMV COLOR 3,IT_KONV-KPOSN COLOR 3,IT_KONV-KSCHL COLOR 3,IT_KONV-KAWRT COLOR 3,IT_KONV-KBETR COLOR 3.
ENDLOOP.
ENDLOOP.
ENDLOOP.[/code]
thanks
reward if helpful

Instantiation an inner class using reflection

I want to instantiate an inner class using the Class.newInstance() method called within the Outer class constructor:
public Outer
public Outer()
Inner.class.newInstance();
private Class Inner { }
When I try it, however, I get an InstantiationException.
Is there some way to do this?
Thanks for the help.
Scott

Here is a consolidation of what everyone posted and it does appear to work. In one of your post you used the getDeclaredConstructors() method and said it was less than ideal; I am not sure what you meant but I suspect it was the hard coded array reference. Anyhow I used the getDeclaredConstructor() method which appears to get non-public constructors also and is basically the same as using the getConstructor() method.
import java.lang.reflect.*;
public class Test35 {
    static public void main(String[] args) {
        Test35 t35 = new Test35();
        t35.testIt();
    private class Inner {
        public String toString() {
            return "Hear I am";
    public void testIt() {
        try {
            Constructor con = Inner.class.getDeclaredConstructor(new Class[] {Test35.class});
            Inner in = (Inner)con.newInstance(new Object[] {this});
            System.out.println(in);
        } catch (Exception e) {
            e.printStackTrace();

Program Design Problem: Inner Class use verse interacting seperate classes?

Similar Messages

Maybe you are looking for