Search Results

Search found 17618 results on 705 pages for 'component design'.

Page 115/705 | < Previous Page | 111 112 113 114 115 116 117 118 119 120 121 122  | Next Page >

  • Give WPF design mode default objects

    - by Janko R
    In my application I have <Rectangle.Margin> <MultiBinding Converter="{StaticResource XYPosToThicknessConverter}"> <Binding Path="XPos"/> <Binding Path="YPos"/> </MultiBinding> </Rectangle.Margin> The Data Context is set during runtime. The application works, but the design window in VS does not show a preview but System.InvalidCastException. That’s why I added a default object in the XYPosToThicknessConverter which is ugly. class XYPosToThicknessConverter : IMultiValueConverter { public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture) { // stupid check to give the design window its default object. if (!(values[0] is IConvertible)) return new System.Windows.Thickness(3, 3, 0, 0); // useful code and exception throwing starts here // ... } } My Questions: What does VS/the process that builds the design window pass to XYPosToThicknessConverter and what is way to find it out by myself. How do I change my XAML code, so that the design window gets its default object and is this the best way to handle this problem? I’m using VS2010RC with Net4.0

    Read the article

  • When virtual inheritance IS a good design?

    - by 7vies
    EDIT3: Please be sure to clearly understand what I am asking before answering (there are EDIT2 and lots of comments around). There are (or were) many answers which clearly show misunderstanding of the question (I know that's also my fault, sorry for that) Hi, I've looked over the questions on virtual inheritance (class B: public virtual A {...}) in C++, but did not find an answer to my question. I know that there are some issues with virtual inheritance, but what I'd like to know is in which cases virtual inheritance would be considered a good design. I saw people mentioning interfaces like IUnknown or ISerializable, and also that iostream design is based on virtual inheritance. Would those be good examples of a good use of virtual inheritance, is that just because there is no better alternative, or because virtual inheritance is the proper design in this case? Thanks. EDIT: To clarify, I'm asking about real-life examples, please don't give abstract ones. I know what virtual inheritance is and which inheritance pattern requires it, what I want to know is when it is the good way to do things and not just a consequence of complex inheritance. EDIT2: In other words, I want to know when the diamond hierarchy (which is the reason for virtual inheritance) is a good design

    Read the article

  • Wired component null in seam EntityHome action

    - by rangalo
    I have a custom EntityHome class. I wire the dependent entity in the wire method, but when I call the action (persist) the wired component is always null. What could be the reason, similar code generated by seam gen is apparently working. Here is the entity class. I have overrden persist method to log the value of the wired element. @Name("roundHome") @Scope(ScopeType.CONVERSATION) public class RoundHome extends EntityHome<Round>{ @In(required = false) private Golfer currentGolfer; @In(create = true) private TeeSetHome teeSetHome; @Override public String persist() { logger.info("Persist called"); if (null != getInstance().getTeeSet() ) { logger.info("teeSet not null in persist"); } else { logger.info("teeSet null in persist"); // wire(); } String retVal = super.persist(); //To change body of overridden methods use File | Settings | File Templates. return retVal; } @Logger private Log logger; public void wire() { logger.info("wire called"); TeeSet teeSet = teeSetHome.getDefinedInstance(); if (null != teeSet) { getInstance().setTeeSet(teeSet); logger.info("Successfully wired the teeSet instance with color: " + teeSet.getColor()); } } public boolean isWired() { logger.info("is wired called"); if(null == getInstance().getTeeSet()) { logger.info("wired teeSet instance is null, the button will be disabled !"); return false; } else { logger.info("wired teeSet instance is NOT null, the button will be enabled !"); logger.info("teeSet color: "+getInstance().getTeeSet().getColor()); return true; } } @RequestParameter public void setRoundId(Long id) { super.setId(id); } @Override protected Round createInstance() { Round round = super.createInstance(); round.setGolfer(currentGolfer); round.setDate(new java.sql.Date(System.currentTimeMillis())); return round; } } Here the xhtml <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE composition PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <ui:composition xmlns="http://www.w3.org/1999/xhtml" xmlns:s="http://jboss.com/products/seam/taglib" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:f="http://java.sun.com/jsf/core" xmlns:h="http://java.sun.com/jsf/html" xmlns:a="http://richfaces.org/a4j" xmlns:rich="http://richfaces.org/rich" template="layout/template.xhtml"> <ui:define name="body"> <h:form id="roundform"> <rich:panel> <f:facet name="header>"> #{roundHome.managed ? 'Edit' : 'Add' } Round </f:facet> <s:decorate id="dateField" template="layout/edit.xhtml"> <ui:define name="label">Date:</ui:define> <rich:calendar id="date" datePattern="dd/MM/yyyy" value="#{round.date}"/> </s:decorate> <s:decorate id="notesField" template="layout/edit.xhtml"> <ui:define name="label">Notes:</ui:define> <h:inputTextarea id="notes" cols="80" rows="3" value="#{round.notes}" /> </s:decorate> <s:decorate id="totalScoreField" template="layout/edit.xhtml"> <ui:define name="label">Total Score:</ui:define> <h:inputText id="totalScore" value="#{round.totalScore}" /> </s:decorate> <s:decorate id="weatherField" template="layout/edit.xhtml"> <ui:define name="label">Weather:</ui:define> <h:selectOneMenu id="weather" value="#{round.weather}"> <s:selectItems var="_weather" value="#{weatherCategories}" label="#{_weather.label}" noSelectionLabel=" Select " /> <s:convertEnum/> </h:selectOneMenu> </s:decorate> <div style="clear: both;"> <span class="required">*</span> required fields </div> </rich:panel> <div class="actionButtons"> <h:commandButton id="save" value="Save" action="#{roundHome.persist}" rendered="#{!roundHome.managed}" /> <!-- disabled="#{!roundHome.wired}" /> --> <h:commandButton id="update" value="Update" action="#{roundHome.update}" rendered="#{roundHome.managed}" /> <h:commandButton id="delete" value="Delete" action="#{roundHome.remove}" rendered="#{roundHome.managed}" /> <s:button id="discard" value="Discard changes" propagation="end" view="/Round.xhtml" rendered="#{roundHome.managed}" /> <s:button id="cancel" value="Cancel" propagation="end" view="/#{empty roundFrom ? 'RoundList' : roundFrom}.xhtml" rendered="#{!roundHome.managed}" /> </div> <rich:tabPanel> <rich:tab label="Tee Set"> <div class="association"> <h:outputText value="Tee set not selected" rendered="#{round.teeSet == null}" /> <rich:dataTable var="_teeSet" value="#{round.teeSet}" rendered="#{round.teeSet != null}"> <h:column> <f:facet name="header">Course</f:facet>#{_teeSet.course.name} </h:column> <h:column> <f:facet name="header">Color</f:facet>#{_teeSet.color} </h:column> <h:column> <f:facet name="header">Position</f:facet>#{_teeSet.pos} </h:column> </rich:dataTable> </div> </rich:tab> </rich:tabPanel> </h:form> </ui:define> </ui:composition>

    Read the article

  • Effectively implementing a game view using java

    - by kdavis8
    I am writing a 2d game in java. The game mechanics are similar to the Pokémon game boy advance series e.g. fire red, ruby, diamond and so on. I need a way to draw a huge map maybe 5000 by 5000 pixels and then load individual in game sprites to across the entirety of the map, like rendering a scene. Game sprites would be things like terrain objects, trees, rocks, bushes, also houses, castles, NPC's and so on. But i also need to implement some kind of camera view class that focuses on the player. the camera view class needs to follow the characters movements throughout the game map but it also needs to clip the rest of the map away from the user's field of view, so that the user can only see the arbitrary proximity adjacent to the player's sprite. The proximity's range could be something like 500 pixels in every direction around the player’s sprite. On top of this, i need to implement an independent resolution for the game world so that the game view will be uniform on all screen sizes and screen resolutions. I know that this does sound like a handful and may fall under the category of multiple questions, but the questions are all related and any advice would be very much appreciated. I don’t need a full source code listing but maybe some pointers to effective java API classes that could make doing what i need to do a lot simpler. Also any algorithmic/ design advice would greatly benefit me as well. example of what i am trying to do in source code form below package myPackage; /** * The Purpose of GameView is to: Render a scene using Scene class, Create a * clipping pane using CameraView class, and finally instantiate a coordinate * grid using Path class. * * Once all of these things have been done, GameView class should then be * instantiated and used jointly with its helper classes. CameraView should be * used as the main drawing image. CameraView is the the window to the game * world.Scene passes data constantly to CameraView so that the entire map flows * smoothly. Path uses the x and y coordinates from camera view to construct * cells for path finding algorithms. */ public class GameView { // Scene is a helper class to game view. it renders the entire map to memory // for the camera view. Scene scene; // Camera View is a helper class to game view. It clips the Scene into a // small image that follows the players coordinates. CameraView Camera; // Path is a helper class to game view. It observes and calculates the // coordinates of camera view and divides them into Grids/Cells for Path // finding. Path path; // this represents the player and has a getSprite() method that will return // the current frame column row combination of the passed sprite sheet. Sprite player; }

    Read the article

  • “I could use a little help here” or “I can do it myself, thank you” for Cloud Projects

    - by BuckWoody
    Windows Azure allows you to write code in languages within the .NET stack, you can use Java, C++, PHP, NodeJS and others. Code is code - other than keeping things stateless, using a Web or Worker Role in Azure is not all that different from working with an on-premises system. However…. Working in a scalable, component-based stateless architecture that can use federated security is not all that common for many developers. Some are used to owning the server, scaling up, and state-full paradigms that have a single security domain. Making the transition whilst trying to create a new software application or even port a previous one can be daunting. Sure, we have absolutely tons of free training, kits, videos, online books and more to learn on your own, but some things like architecture can be pivotal as you move along. So the question is, should you just strike out on your own for a Cloud project, or get Microsoft Consulting Services or another partner to work with you on your first one? I use a few decision points to help guide the projects I assist in. Note: I’m a huge fan of having help that ends up giving you training and leaves you in charge. If you do engage with someone to help you, make sure you keep this clear and take more and more ownership yourself as the project progresses. How much time do you have? Usually the first thing I ask is about the timeline for the project. It doesn’t matter how skilled you are, if you have a short window to get things done it’s better to get help - especially if this is your first cloud project. Having someone that knows the platform well can save you amazing amounts of time. If you have longer, then start with the training in the link above and once you feel confident, jump in. How complex is the project? If there are a lot of moving parts, it’s best to engage a partner. The reason is that certain interactions - particularly things like Service Bus or Data Integration  - can be quite different than what you may have encountered before. How many people do you have? I have a “pizza rule” about projects I’ve used in my career - if it takes over two pizzas to feed everyone on the project, it’s too big and will fail. That being said, one developer and a one-week deadline does not a good project make, usually. It’s best to have at least one architect (or someone in that role) guiding the project along, and at least two developers to work on a cloud project. That’s a generalization of course, since I’ve seen great software on Azure with one developer writing code all by herself, but for more complex projects, more (to a point) is better. The nice thing about bringing on a partner is that you don’t have to hire them full time - they help you and then they go away. How critical is the project? There’s no shame in using some help. If the platform is new, if the project is large and complex, and if it is critical to the business, you should engage a partner. That’s regardless of Cloud or anything else - get some help. You don’t want to hit your company’s bottom line in a negative way, but you have to innovate and get them a competitive advantage. Do your research, make sure the partner is qualified to help you, and get it done. Don’t let these questions scare you off. There are lots of projects you can implement on Windows and SQL Azure with nothing other than the Software Development Kit (SDK) that you get for free with Windows Azure. And assistance comes in many forms - sometimes just phone support, a friend you can ask. Microsoft Consulting Services or any of our great partners. You can get help on just the architecture piece or have them show you how to write the code. They’ll get involved as little or as much as you like.

    Read the article

  • Best Platform/Engine for turn based Client/Server Android game

    - by Paradine
    I'm currently designing a turn based game for tablets. Initially for Android with porting to iOS later considered in design. I'm having trouble narrowing down the available technologies to even know where to spend my research time. I am hoping that if I explain what I am trying to achieve someone may be able to suggest a platform and/or engine. I've looked into some of the open source Engines ( http://www.cuteandroid.com/ten-open-source-android-2d-or-3d-game-engine-for-android-developers ) and some appear to handle much of what I might require - although with a higher focus on graphics than i need. Mages looks interesting although development appears to have ceased. If I could somehow leverage GoogleApps that would be excellent. Here is what I am trying to achieve: PvP turn based strategy game over internet - minimal animation and bandwidth required Players match up online using MetaGame system MatchID created on Resolution Server and Game starts Clients have 30 second countdown to select MoveString Clients sends small secure timestamped and MatchIDed MoveString to Resolution server Resolution server looks up Move String for each player, Resolves and Updates Players status in MatchID on Server Resolution server updates Client Views Repeat until victory conditions met - MatchID Closed, Rewards earned in MetaGame There will also need to be a full social and account system and metagame backend - but this could be running on separate system(s) Tablet in Offline mode would be catalog browsing and perhaps single player AI - bum I'm focusing on the Resolution Server at this point I'm not even certain if I would be looking at an Android App or a WebApp at this stage! I want a custom GUI so I guess an app - but maybe as I have little animation a WebApp might also work. Probably some combination of both. There will be very small overhead in data between client server - essentially a small text string every 30 seconds sent to the Resolution server which looks up the Effect and applies it to the Opponents string and determines some results to apply to the match. The client view is updated minimally with the results (only 5 in game Integers tracked) - perhaps triggering small animations/popups on the client to show the end result. e.g Explosion. If you have suggestions for a good technology or platform to best achieving the Resolution Server I'd love to hear. Also if you have experience with open source Engines - and could narrow down which (if any ) might be most suitable that would be a big help. Thanks in advance

    Read the article

  • Game timings and formats

    - by topright
    There are more or less standardized TV-show/movie formats and recommended timings: 1. By the early 1960s, television companies commonly presented half-hour long "comedy" series, or one hour long "dramas." Half-hour series were mostly restricted to situation comedy or family comedy, and were usually aired with either a live or artificial laugh track. One hour dramas included genre series such as police and detective series, westerns, science fiction, and, later, serialized prime time soap operas. Programs today still overwhelmingly conform to these half-hour and one hour guidelines. Source 2. In the United States, most medical dramas are one hour long. Source 3. Traditionally serials were broadcast as fifteen minute installments each weekday in daytime slots. In 1956 As the World Turns debuted as the first half-hour soap opera. All soap operas broadcast half-hour episodes by the end of the 1960s. With increased popularity in the 1970s most soap operas expanded to an hour (Another World even expanded to ninety minutes for a short time). More than half of the serials had expanded to one hour episodes by 1980. As of 2010, six of the seven US serials air one hour episodes each weekday. Source Interesting. Are there any standards of timing in game development? Well, 5-20 minutes casual games, of course. There is even a "5-minutes-game" site. And 1-hour-gamer site. Are there 1-week, 1-year, 1-eternity game formats? Chess and Go - deep games that you can study all your life; but they are played in hour or several days (pro games). Addictive long-term online role-playing games (without win-condition) are played in monthes and, possibly, years. Replayability is an important factor to consider. It's good when game design document contains a line: "A game is designed for solving in X hours". How can it be measured before there is any prototype or demo? When you know your game format, you know your audience (and vice versa). It is practical question. Are there psychological researches about dynamic of gaming interest and involvement? And is there a correlation between game format and game genre?

    Read the article

  • Music Notation Editor - Refactoring view creation logic elsewhere

    - by Cyril Silverman
    Let me preface by saying that knowing some elementary music theory and music notation may be helpful in grasping the problem at hand. I'm currently building a Music Notation and Tablature Editor (in Javascript). But I've come to a point where the core parts of the program are more or less there. All functionality I plan to add at this point will really build off the foundation that I've created. As a result, I want to refactor to really solidify my code. I'm using an API called VexFlow to render notation. Basically I pass the parts of the editor's state to VexFlow to build the graphical representation of the score. Here is a rough and stripped down UML diagram showing you the outline of my program: In essence, a Part has many Measures which has many Notes which has many NoteItems (yes, this is semantically weird, as a chord is represented as a Note with multiple NoteItems, individual pitches or fret positions). All of the relationships are bi-directional. There are a few problems with my design because my Measure class contains the majority of the entire application view logic. The class holds the data about all VexFlow objects (the graphical representation of the score). It contains the graphical Staff object and the graphical notes. (Shouldn't these be placed somewhere else in the program?) While VexFlowFactory deals with actual creation (and some processing) of most of the VexFlow objects, Measure still "directs" the creation of all the objects and what order they are supposed to be created in for both the VexFlowStaff and VexFlowNotes. I'm not looking for a specific answer as you'd need a much deeper understanding of my code. Just a general direction to go in. Here's a thought I had, create an MeasureView/NoteView/PartView classes that contains the basic VexFlow objects for each class in addition to any extraneous logic for it's creation? but where would these views be contained? Do I create a ScoreView that is a parallel graphical representation of everything? So that ScoreView.render() would cascade down PartView and call render for each PartView and casade down into each MeasureView, etc. Again, I just have no idea what direction to go in. The more I think about it, the more ways to go seem to pop into my head. I tried to be as concise and simplistic as possible while still getting my problem across. Please feel free to ask me any questions if anything is unclear. It's quite a struggle trying to dumb down a complicated problem to its core parts.

    Read the article

  • Questions re: Eclipse Jobs API

    - by BenCole
    Similar to http://stackoverflow.com/questions/8738160/eclipse-jobs-api-for-a-stand-alone-swing-project This question mentions the Jobs API from the Eclipse IDE: ...The disadvantage of the pre-3.0 approach was that the user had to wait until an operation completed before the UI became responsive again. The UI still provided the user the ability to cancel the currently running operation but no other work could be done until the operation completed. Some operations were performed in the background (resource decoration and JDT file indexing are two such examples) but these operations were restricted in the sense that they could not modify the workspace. If a background operation did try to modify the workspace, the UI thread would be blocked if the user explicitly performed an operation that modified the workspace and, even worse, the user would not be able to cancel the operation. A further complication with concurrency was that the interaction between the independent locking mechanisms of different plug-ins often resulted in deadlock situations. Because of the independent nature of the locks, there was no way for Eclipse to recover from the deadlock, which forced users to kill the application... ...The functionality provided by the workspace locking mechanism can be broken down into the following three aspects: Resource locking to ensure multiple operations did not concurrently modify the same resource Resource change batching to ensure UI stability during an operation Identification of an appropriate time to perform incremental building With the introduction of the Jobs API, these areas have been divided into separate mechanisms and a few additional facilities have been added. The following list summarizes the facilities added. Job class: support for performing operations or other work in the background. ISchedulingRule interface: support for determining which jobs can run concurrently. WorkspaceJob and two IWorkspace#run() methods: support for batching of delta change notifications. Background auto-build: running of incremental build at a time when no other running operations are affecting resources. ILock interface: support for deadlock detection and recovery. Job properties for configuring user feedback for jobs run in the background. The rest of this article provides examples of how to use the above-mentioned facilities... In regards to above API, is this an implementation of a particular design pattern? Which one?

    Read the article

  • Programming and Ubiquitous Language (DDD) in a non-English domain

    - by Sandor Drieënhuizen
    I know there are some questions already here that are closely related to this subject but none of them take Ubiquitous Language as the starting point so I think that justifies this question. For those who don't know: Ubiquitous Language is the concept of defining a (both spoken and written) language that is equally used across developers and domain experts to avoid inconsistencies and miscommunication due to translation problems and misunderstanding. You will see the same terminology show up in code, conversations between any team member, functional specs and whatnot. So, what I was wondering about is how to deal with Ubiquitous Language in non-English domains. Personally, I strongly favor writing programming code in English completely, including comments but ofcourse excluding constants and resources. However, in a non-English domain, I'm forced to make a decision either to: Write code reflecting the Ubiquitous Language in the natural language of the domain. Translate the Ubiquitous Language to English and stop communicating in the natural language of the domain. Define a table that defines how the Ubiquitous Language translates to English. Here are some of my thoughts based on these options: 1) I have a strong aversion against mixed-language code, that is coding using type/member/variable names etc. that are non-English. Most programming languages 'breathe' English to a large extent and most of the technical literature, design pattern names etc. are in English as well. Therefore, in most cases there's just no way of writing code entirely in a non-English language so you end up with mixed languages anyway. 2) This will force the domain experts to start thinking and talking in the English equivalent of the UL, something that will probably not come naturally to them and therefore hinders communication significantly. 3) In this case, the developers communicate with the domain experts in their native language while the developers communicate with each other in English and most importantly, they write code using the English translation of the UL. I'm sure I don't want to go for the first option and I think option 3 is much better than option 2. What do you think? Am I missing other options? UPDATE Today, about year later, having dealt with this issue on a daily basis, I have to say that option 3 has worked out pretty well for me. It wasn't as tedious as I initially feared and translating in real time while talking to the client wasn't a problem either. I also found the following advantages to be true, based on my experience. Translating the UL makes you pay more attention to defining the UL and even the domain itself, especially when you don't know how to translate a term and you have to start looking through dictionaries etc. This has even caused me to reconsider domain modeling decisions a few times. It helps you make your knowledge of the English language more profound. Obviously, your code is much more pleasant to look at instead of being a mind boggling obscenity.

    Read the article

  • As a web designer, which language should I learn first for my feature career? (PHP or JavaScript) [closed]

    - by kdevs3
    Possible Duplicates: Best Programming Language for Web Development How can I choose a web development language? What language will you choose if you are going to build something big? What is the right option of programming languages and tools for building our website? What is the easiest web programing language at....? Well, I'm more of a basic web designer. I know the easy stuff pretty well. (Ya know, html, css) But I've been trying to take it to the next step and I'm contemplating about what I should learn that will help me out the most in my future web design/programming career, should it be JavaScript or maybe I should try to learn a back end programming language such as PHP. Lately, I have been hearing about a lot how JavaScript is so great and useful now, because of libraries such as jQuery and what possibility's it can bring by using Node.js and other frameworks. I've only learned the most basic of JavaScript and used some jQuery (mostly plugins) so i wouldn't know at all of what it can actually do. Would JS being so popular as it is now and useful, be a reason to stick with JavaScript and only learn it that for now? Or as a web designer, how important would it be to learn how to make a web application/website operate and functional, and know how to work with servers, etc? (Such as getting forms to work and sending data to the server and back) I've took a look at frameworks such as Code Igniter before, and looks really simple to get started with if I try to learn PHP, But I'm not sure how important it is for my career and what I would gain out of it. I'm asking because I can't decide what I should learn first. When I select it, I really want to take my time and learn the language. I don't want to spend time on learning multiple languages at the same time, so I need to pick wisely. I'm trying to turn the right direction so my career can hopefully be successful in the feature. (If money/gaining a job asked if its important, then its a yeah, it is a bit) I'm hoping I can get opinions and suggestions on this question, thanks for giving me your thoughts also.

    Read the article

  • Designing for an algorithm that reports progress

    - by Stefano Borini
    I have an iterative algorithm and I want to print the progress. However, I may also want it not to print any information, or to print it in a different way, or do other logic. In an object oriented language, I would perform the following solutions: Solution 1: virtual method have the algorithm class MyAlgoClass which implements the algo. The class also implements a virtual reportIteration(iterInfo) method which is empty and can be reimplemented. Subclass the MyAlgoClass and override reportIteration so that it does what it needs to do. This solution allows you to carry additional information (for example, the file unit) in the reimplemented class. I don't like this method because it clumps together two functionalities that may be unrelated, but in GUI apps it may be ok. Solution 2: observer pattern the algorithm class has a register(Observer) method, keeps a list of the registered observers and takes care of calling notify() on each of them. Observer::notify() needs a way to get the information from the Subject, so it either has two parameters, one with the Subject and the other with the data the Subject may pass, or just the Subject and the Observer is now in charge of querying it to fetch the relevant information. Solution 3: callbacks I tend to see the callback method as a lightweight observer. Instead of passing an object, you pass a callback, which may be a plain function, but also an instance method in those languages that allow it (for example, in python you can because passing an instance method will remain bound to the instance). C++ however does not allow it, because if you pass a pointer to an instance method, this will not be defined. Please correct me on this regard, my C++ is quite old. The problem with callbacks is that generally you have to pass them together with the data you want the callback to be invoked with. Callbacks don't store state, so you have to pass both the callback and the state to the Subject in order to find it at callback execution, together with any additional data the Subject may provide about the event is reporting. Question My question is relative to the fact that I need to implement the opening problem in a language that is not object oriented, namely Fortran 95, and I am fighting with my usual reasoning which is based on python assumptions and style. I think that in Fortran the concept is similar to C, with the additional trouble that in C you can store a function pointer, while in Fortran 95 you can only pass it around. Do you have any comments, suggestions, tips, and quirks on this regard (in C, C++, Fortran and python, but also in any other language, so to have a comparison of language features that can be exploited on this regard) on how to design for an algorithm that must report progress to some external entity, using state from both the algorithm and the external entity ?

    Read the article

  • How to build a 4x game?

    - by Marco
    I'm trying to study how succefully implement a 4x game. Area of interest: 1) map data: how to store stellars systems (graphs?), how to generate them and so on.. 2) multiplayer: how to organize code in a non graphical server and a client to display it 3) command system: what are patters to catch user and ai decisions and handle them, adding at first "explore" and "colonize" then "combat", "research", "spy" and so on (commands can affect ships, planets, research, etc..) 4) ai system: ai can use commands to expand, upgrade planets and ship I know is a big questions, so help is appreciated :D 1) Map data Best choice is have a graph to model a galaxy. A node is a stellar system and every system have a list of planets. Ship cannot travel outside of predefined paths, like in Ascendancy: http://www.abandonia.com/files/games/221/Ascendancy_2.png Every connection between two stellar systems have a cost, in turns. Generate a galaxy is only a matter of: - dimension: number of stellar systems, - variety: randomize number of planets and types (desertic, earth, etc..), - positions of each stellar system on game space - connections: assure that exist a path between every node, so graph is "connected" (not sure if this a matematically correct term) 2) Multiplayer Game is organized in turns: player 1, player 2, ai1, ai2. Server take care of all data and clients just diplay it and collect data change. Because is a turn game, latency is not a problem :D 3) Command system I would like to design a hierarchy of commands to take care of this aspect: abstract Genericcommand (target) ExploreCommand (Ship) extends genericcommand colonizeCommand (Ship) buildcommand(planet, object) and so on. In my head all this commands are stored in a queue for every planets, ships or reasearch center or spy, and each turn a command is sent to a server to apply command and change data state 4) ai system I don't have any idea about this. Is a big topic and what I want is a simple ai. Something like "expand and fight against everyone". I think about a behaviour tree to control ai moves, so I can develop an ai that try to build ships to expand and then colonize planets, upgrade them throught science and combat enemies. Could be done with a finite state machine too ? any ideas, resources, article are welcome!

    Read the article

  • Music Notation Editor - Refactoring view creation logic elseware

    - by Cyril Silverman
    Let me preface by saying that knowing some elementary music theory and music notation may be helpful in grasping the problem at hand. I'm currently building a Music Notation and Tablature Editor (in Javascript). But I've come to a point where the core parts of the program are more or less there. All functionality I plan to add at this point will really build off the foundation that I've created. As a result, I want to refactor to really solidify my code. I'm using an API called VexFlow to render notation. Basically I pass the parts of the editor's state to VexFlow to build the graphical representation of the score. Here is a rough and stripped down UML diagram showing you the outline of my program: In essence, a Part has many Measures which has many Notes which has many NoteItems (yes, this is semantically weird, as a chord is represented as a Note with multiple NoteItems, individual pitches or fret positions). All of the relationships are bi-directional. There are a few problems with my design because my Measure class contains the majority of the entire application view logic. The class holds the data about all VexFlow objects (the graphical representation of the score). It contains the graphical Staff object and the graphical notes. (Shouldn't these be placed somewhere else in the program?) While VexFlowFactory deals with actual creation (and some processing) of most of the VexFlow objects, Measure still "directs" the creation of all the objects and what order they are supposed to be created in for both the VexFlowStaff and VexFlowNotes. I'm not looking for a specific answer as you'd need a much deeper understanding of my code. Just a general direction to go in. Here's a thought I had, create an MeasureView/NoteView/PartView classes that contains the basic VexFlow objects for each class in addition to any extraneous logic for it's creation? but where would these views be contained? Do I create a ScoreView that is a parallel graphical representation of everything? So that ScoreView.render() would cascade down PartView and call render for each PartView and casade down into each MeasureView, etc. Again, I just have no idea what direction to go in. The more I think about it, the more ways to go seem to pop into my head. I tried to be as concise and simplistic as possible while still getting my problem across. Please feel free to ask me any questions if anything is unclear. It's quite a struggle trying to dumb down a complicated problem to its core parts.

    Read the article

  • JS closures - Passing a function to a child, how should the shared object be accessed

    - by slicedtoad
    I have a design and am wondering what the appropriate way to access variables is. I'll demonstrate with this example since I can't seem to describe it better than the title. Term is an object representing a bunch of time data (a repeating duration of time defined by a bunch of attributes) Term has some print functionality but does not implement the print functions itself, rather they are passed in as anonymous functions by the parent. This would be similar to how shaders can be passed to a renderer rather than defined by the renderer. A container (let's call it Box) has a Schedule object that can understand and use Term objects. Box creates Term objects and passes them to Schedule as required. Box also defines the print functions stored in Term. A print function usually takes an argument and uses it to return a string based on that argument and Term's internal data. Sometime the print function could also use data stored in Schedule, though. I'm calling this data shared. So, the question is, what is the best way to access this shared data. I have a lot of options since JS has closures and I'm not familiar enough to know if I should be using them or avoiding them in this case. Options: Create a local "reference" (term used lightly) to the shared data (data is not a primitive) when defining the print function by accessing the shared data through Schedule from Box. Example: var schedule = function(){ var sched = Schedule(); var t1 = Term( function(x){ // Term.print() return (x + sched.data).format(); }); }; Bind it to Term explicitly. (Pass it in Term's constructor or something). Or bind it in Sched after Box passes it. And then access it as an attribute of Term. Pass it in at the same time x is passed to the print function, (from sched). This is the most familiar way for my but it doesn't feel right given JS's closure ability. Do something weird like bind some context and arguments to print. I'm hoping the correct answer isn't purely subjective. If it is, then I guess the answer is just "do whatever works". But I feel like there are some significant differences between the approaches that could have a large impact when stretched beyond my small example.

    Read the article

  • What are the differences between abstract classes, interfaces, and when to use them

    - by user66662
    Recently I have started to wrap my head around OOP, and I am now to the point where the more I read about the differences between Abstract classes and Interfaces the more confused I become. So far, neither can be instantiated. Interfaces are more or less structural blueprints that determine the skeleton and abstracts are different by being able to partially develop code. I would like to learn more about these through my specific situation. Here is a link to my first question if you would like a little more background information: What is a good design model for my new class? Here are two classes I created: class Ad { $title; $description $price; function get_data($website){ } function validate_price(){ } } class calendar_event { $title; $description $start_date; function get_data($website){ //guts } function validate_dates(){ //guts } } So, as you can see these classes are almost identical. Not shown here, but there are other functions, like get_zip(), save_to_database() that are common across my classes. I have also added other classes Cars and Pets which have all the common methods and of course properties specific to those objects (mileage, weight, for example). Now I have violated the DRY principle and I am managing and changing the same code across multiple files. I intend on having more classes like boats, horses, or whatever. So is this where I would use an interface or abstract class? From what I understand about abstract classes I would use a super class as a template with all of the common elements built into the abstract class, and then add only the items specifically needed in future classes. For example: abstract class content { $title; $description function get_data($website){ } function common_function2() { } function common_function3() { } } class calendar_event extends content { $start_date; function validate_dates(){ } } Or would I use an interface and, because these are so similar, create a structure that each of the subclasses are forced to use for integrity reasons, and leave it up to the end developer who fleshes out that class to be responsible for each of the details of even the common functions. my thinking there is that some 'common' functions may need to be tweaked in the future for the needs of their specific class. Despite all that above, if you believe I am misunderstanding the what and why of abstracts and interfaces altogether, by all means let a valid answer to be stop thinking in this direction and suggest the proper way to move forward! Thanks!

    Read the article

  • .Net Application & Database Modularity/Reuse

    - by Martaver
    I'm looking for some guidance on how to architect an app with regards to modularity, separation of concerns and re-usability. I'm working on an application (ASP.Net, C#) that has distinctly generic chunks of functionality, that I'd love to be able to lift out, all layers, into re-usable components. This means the module handles the database schema, data access, API, everything so that the next time I want to use it I can just register the module and hook into it. Developing modules of re-usable functionality is a no-brainer, but what is really confusing me is what to do when it comes to handling a core re-usable database schema that serves the module's functionality. In an ideal world, I would register a module and it would ensure that the associated database schema exists in the DB. I would code on the assumption that the tables exist, calling the module's functionality through the DLL, agnostic of the database layer. Kind of like Enterprise Library's Caching/Logging Application Block, which can create a DB schema in the target DB to use as a data store. My Questions is: What do you think is the best way to achieve this, firstly, in terms design architecture, and secondly solution structure. What patterns/frameworks do you know that exist & support this kind of thing? My thoughts so far: I mostly use Entity Framework and SQL Server DB Projects. I thought about a 'black box' approach to modules of functionality. I could use use a code-first approach in EF4, and use the ObjectContext to create a database when the module is initialized. However this means that all of the entities that my module encapsulates would be disconnected from the rest of the application because they belonged to an abstracted ObjectContext. Further - Creating appropriate indexes and references between domain entities and the module's entities would be impossible to do practically. I've thought of adopting Enterprise Library and creating my own Application Blocks. I'm not sure how this would play nice with Entity Framework (if at all) though. I like the idea of building on proven patterns & practices to encapsulate established, reusable functionality. I thought of abandoning Entity Framework for the Module, and just creating a separate DB schema for the module with its own set of stored procedures & ADO.Net. Then deploying the script at run-time if interrogation shows that it doesn't exist. But once again, for application developing outside of the application, I would want to use Entity Framework and I would have to use the module separately, disconnected from the domain ObjectContext. Has anyone had experience developing these sorts of full-stack modules? What advice can you offer? Am I biting off more than I can chew?

    Read the article

  • A solution for a PHP website without a framework

    - by lortabac
    One of our customers asked us to add some dynamic functionality to an existent website, made of several static HTML pages. We normally work with an MVC framework (mostly CodeIgniter), but in this case moving everything to a framework would require too much time. Since it is not a big project, not having the full functionality of a framework is not a problem. But the question is how to keep code clean. The solution I came up with is to divide code in libraries (the application's API) and models. So inside HTML there will only be API calls, and readability will not be sacrificed. I implemented this with a sort of static Registry (sorry if I'm wrong, I am not a design pattern expert): <?php class Custom_framework { //Global database instance private static $db; //Registered models private static $models = array(); //Registered libraries private static $libraries = array(); //Returns a database class instance static public function get_db(){ if(isset(self::$db)){ //If instance exists, returns it return self::$db; } else { //If instance doesn't exists, creates it self::$db = new DB; return self::$db; } } //Returns a model instance static public function get_model($model_name){ if(isset(self::$models[$model_name])){ //If instance exists, returns it return self::$models[$model_name]; } else { //If instance doesn't exists, creates it if(is_file(ROOT_DIR . 'application/models/' . $model_name . '.php')){ include_once ROOT_DIR . 'application/models/' . $model_name . '.php'; self::$models[$model_name] = new $model_name; return self::$models[$model_name]; } else { return FALSE; } } } //Returns a library instance static public function get_library($library_name){ if(isset(self::$libraries[$library_name])){ //If instance exists, returns it return self::$libraries[$library_name]; } else { //If instance doesn't exists, creates it if(is_file(ROOT_DIR . 'application/libraries/' . $library_name . '.php')){ include_once ROOT_DIR . 'application/libraries/' . $library_name . '.php'; self::$libraries[$library_name] = new $library_name; return self::$libraries[$library_name]; } else { return FALSE; } } } } Inside HTML, API methods are accessed like this: <?php echo Custom_framework::get_library('My_library')->my_method(); ?> It looks to me as a practical solution. But I wonder what its drawbacks are, and what the possible alternatives.

    Read the article

  • Turn-Based RPG Battle Instance Layout For Larger Groups

    - by SoulBeaver
    What a title, eh? I'm currently designing a videogame; a turn-based RPG like Final Fantasy (because everybody knows Final Fantasy). It's a 2D sprite game. These are my ideas for combat: -The player has a group of 15 members (main character included) -During battle, five of the group are designated as active, and appear in the battle. -These five may be switched out at leisure, or when one of the five die. -At any time, the Waiting members can cast buffs, be healed by the active members, or perform special attacks. -Battles should contain 10+ monsters at least. I'm aiming for 20, but I'm not sure if that's possible yet. -Battles should feel larger than normal due to the interaction of Waiting members, active members and the increased amount of monsters per battle. -The player has two rows in which to put the Active members: front and back. -Depending on the implementation, I might allow comboing of player attacks and skills. These are just design ideas, so beware! I have not been able to test this out yet- I have no idea yet if any of these ideas bunched together will make for a compelling game. What sounds good on paper doesn't necessarily have to be good in practice! What I'm asking now is how to create the layout for this. My starting point are the battles in Final Fantasy VI, with up to 5-6 monsters on the left and the characters on the right- monsters on both sides if it's a pincer attack. However, this view would not work feasible with my goal of 20 monsters and 5 characters. All the monsters on the left would appear cluttered unless I scale them far far back. If I create a pincer-like map, then there would be no real pincer-attack possible. If I space the monsters out I force the player to scroll the screen- a game mechanic I've come across and not enjoyed imho. My question is: does anybody have any layouts or guides for designing battle maps in turn-based RPGs, especially with a larger number of enemies taken into consideration? How should it look? I am not asking for specific combat mechanics, just the layout for the moment.

    Read the article

  • How do you take into account usability and user requirements for your application?

    - by voroninp
    Our team supports BackOffice application: a mix of WinForm and WPF windows. (about 80 including dialogs). Really a kind of a Swiss Army Knife. It is used by developers, tech writers, security developers, testers. The requirements for new features come quite often and sometimes we play Wizard of Oz to decide which GUI our users like the most. And it usually happens (I admit it can be just my subjective interpretation of the reality) that one tiny detail giving the flavor of good usability to our app requires a lot of time. This time is being spent on 'fighting' with GUI framework making it act like we need. And it very difficult to make estimations for this type of tasks (at least for me and most members of our team). Scrum poker is not a help either. Management often considers this usability perfectionism to be a waste of time. On the other hand an accumulated affect of features where each has some little usability flaw frustrates users. But the same users want frequent releases and instant bug fixes. Hence, no way to get the positive feedback: there is always somebody who is snuffy. I constantly feel myself as competing with ourselves: more features - more bugs/tasks/architecture. We are trying to outrun the cart we are pushing. New technologies arrive and some of them can potentially help to improve the design or decrease task implementation time but these technologies require learning, prototyping and so on. Well, that was a story. And now is the question: How do you balance between time pressure, product quality, users and management satisfaction? When and how do you decide to leave the problem with not a perfect but to some extent acceptable solution, how often do you make these decisions? How do you do with your own satisfaction? What are your priorities? P.S. Please keep in mind, we are a BackOffice team, we have neither dedicated technical writer nor GUI designer. The tester have joined us recently. We've much work to do and much freedom concerning 'how'. I like it because it fosters creativity but I don't want to become too nerdy perfectionist.

    Read the article

  • Lazy Processing of Streams

    - by Giorgio
    I have the following problem scenario: I have a text file and I have to read it and split it into lines. Some lines might need to be dropped (according to criteria that are not fixed). The lines that are not dropped must be parsed into some predefined records. Records that are not valid must be dropped. Duplicate records may exist and, in such a case, they are consecutive. If duplicate / multiple records exist, only one item should be kept. The remaining records should be grouped according to the value contained in one field; all records belonging to the same group appear one after another (e.g. AAAABBBBCCDEEEFF and so on). The records of each group should be numbered (1, 2, 3, 4, ...). For each group the numbering starts from 1. The records must then be saved somewhere / consumed in the same order as they were produced. I have to implement this in Java or C++. My first idea was to define functions / methods like: One method to get all the lines from the file. One method to filter out the unwanted lines. One method to parse the filtered lines into valid records. One method to remove duplicate records. One method to group records and number them. The problem is that the data I am going to read can be too big and might not fit into main memory: so I cannot just construct all these lists and apply my functions one after the other. On the other hand, I think I do not need to fit all the data in main memory at once because once a record has been consumed all its underlying data (basically the lines of text between the previous record and the current record, and the record itself) can be disposed of. With the little knowledge I have of Haskell I have immediately thought about some kind of lazy evaluation, in which instead of applying functions to lists that have been completely computed, I have different streams of data that are built on top of each other and, at each moment, only the needed portion of each stream is materialized in main memory. But I have to implement this in Java or C++. So my question is which design pattern or other technique can allow me to implement this lazy processing of streams in one of these languages.

    Read the article

  • The term "interface" in C++

    - by Flexo
    Java makes a clear distinction between class and interface. (I believe C# does also, but I have no experience with it). When writing C++ however there is no language enforced distinction between class and interface. Consequently I've always viewed interface as a workaround for the lack of multiple inheritance in Java. Making such a distinction feels arbitrary and meaningless in C++. I've always tended to go with the "write things in the most obvious way" approach, so if in C++ I've got what might be called an interface in Java, e.g.: class Foo { public: virtual void doStuff() = 0; ~Foo() = 0; }; and I then decided that most implementers of Foo wanted to share some common functionality I would probably write: class Foo { public: virtual void doStuff() = 0; ~Foo() {} protected: // If it needs this to do its thing: int internalHelperThing(int); // Or if it doesn't need the this pointer: static int someOtherHelper(int); }; Which then makes this not an interface in the Java sense anymore. Instead C++ has two important concepts, related to the same underlying inheritance problem: virtual inhertiance Classes with no member variables can occupy no extra space when used as a base "Base class subobjects may have zero size" Reference Of those I try to avoid #1 wherever possible - it's rare to encounter a scenario where that genuinely is the "cleanest" design. #2 is however a subtle, but important difference between my understanding of the term "interface" and the C++ language features. As a result of this I currently (almost) never refer to things as "interfaces" in C++ and talk in terms of base classes and their sizes. I would say that in the context of C++ "interface" is a misnomer. It has come to my attention though that not many people make such a distinction. Do I stand to lose anything by allowing (e.g. protected) non-virtual functions to exist within an "interface" in C++? (My feeling is the exactly the opposite - a more natural location for shared code) Is the term "interface" meaningful in C++ - does it imply only pure virtual or would it be fair to call C++ classes with no member variables an interface still?

    Read the article

  • Application workflow

    - by manseuk
    I am in the planning process for a new application, the application will be written in PHP (using the Symfony 2 framework) but I'm not sure how relevant that is. The application will be browser based, although there will eventually be API access for other systems to interact with the data stored within the application, again probably not relavent at this point. The application manages SIM cards for lots of different providers - each SIM card belongs to a single provider but a single customer might have many SIM cards across many providers. The application allows the user to perform actions against the SIM card - for example Activate it, Barr it, Check on its status etc Some of the providers provide an API for doing this - so a single access point with multiple methods eg activateSIM, getStatus, barrSIM etc. The method names differ for each provider and some providers offer methods for extra functions that others don't. Some providers don't have APIs but do offer these methods by sending emails with attachments - the attachments are normally a CSV file that contains the SIM reference and action required - the email is processed by the provider and replied to once the action has been complete. To give you an example - the front end of my application will provide a customer with a list of SIM cards they own and give them access to the actions that are provided by the provider of each specific SIM card - some methods may require extra data which will either be stored in the backend or collected from the user frontend. Once the user has selected their action and added any required data I will handle the process in the backend and provide either instant feedback, in the case of the providers with APIs, or start the process off by sending an email and waiting for its reply before processing it and updating the backend so that next time the user checks the SIM card its status is correct (ie updated by a backend process). My reason for creating this question is because I'm stuck !! I'm confused about how to approach the actual workflow logic. I was thinking about creating a Provider Interface with the most common methods getStatus, activateSIM and barrSIM and then implementing that interface for each provider. So class Provider1 implements Provider - Then use a Factory to create the required class depending on user selected SIM card and invoking the method selected. This would work fine if all providers offered the same methods but they don't - there are a subset which are common but some providers offer extra methods - how can I implement that flexibly ? How can I deal with the processes where the workflow is different - ie some methods require and API call and value returned and some require an email to be sent and the next stage of the process doesn't start until the email reply is recieved ... Please help ! (I hope this is a readable question and that this is the correct place to be asking) Update I guess what I'm trying to avoid is a big if or switch / case statement - some design pattern that gives me a flexible approach to implementing this kind of fluid workflow .. anyone ?

    Read the article

  • Development Approach: User Interface In or Domain Model Out?

    - by Berin Loritsch
    While I've never delivered anything using Smalltalk, my brief time playing with it has definitely left its mark. The only way to describe the experience is MVC the way it was meant to be. Essentially, all the heavy lifting for your application is done in the business objects (or domain model if you are so inclined). The standard controls are bound to the business objects in some way. For example, a text box is mapped to an object's field (the field itself is an object so it's easy to do). A button would mapped to a method. This is all done with a very simple and natural API. We don't have to think about binding objects, etc. It just works. Yet, in many newer languages and APIs you are forced to think from the outside in. First with C++ and MFC, and now with C# and WPF, Microsoft has gotten it's developer world hooked on GUI builders where you build your application by implementing event handlers. Java Swing development isn't so different, only you are writing the code to instantiate the controls on the form yourself. For some projects, there may never even be a domain model--just event handlers. I've been in and around this model for most of my carreer. Each way forces you to think differently. With the Smalltalk approach, your domain is smart while your GUI is dumb. With the default VisualStudio approach, your GUI is smart while your domain model (if it exists) is rather anemic. Many developers that I work with see value in the Smalltalk approach, and try to shoehorn that approach into the VisualStudio environment. WPF has some dynamic binding features that makes it possible; but there are limitations. Inevitably some code that belongs in the domain model ends up in the GUI classes. So, which way do you design/develop your code? Why? GUI first. User interaction is paramount. Domain first. I need to make sure the system is correct before we put a UI on it. There's pros and cons for either approach. Domain model fits in there with crystal cathedrals and pie in the sky. GUI fits in there with quick and dirty (sometimes really dirty). And for an added bonus: How do you make sure the code is maintainable?

    Read the article

  • What is the right way to group this project into classes?

    - by sigil
    I originally asked this on SO, where it was closed and recommended that I ask it here instead. I'm trying to figure out how to group all the functions necessary for my project into classes. The goal of the project is to execute the following process: Get the user's FTP credentials (username & password). Check to make sure the credentials establish a valid connection to the FTP server. Query several Sharepoint lists and join the results of those queries to create a list of items that need to have action taken on them. Each item in the list has a folder. For each item: Zip the contents of the folder. Upload the folder to the FTP server using SFTP Update the item's Sharepoint data. Email the user an Excel report showing, e.g., Items without folder paths Items that failed to zip or upload Steps 2-5 are performed on a periodic basis; if step 2 returns an invalid connection, the user is alerted and the process returns to step 1. If at any point the user presses a certain key, the process terminates. I've defined the following set of classes, each of which is in its own .cs file: SFTP: file transfer processes DataHandler: Sharepoint data retrieval/querying/updating processes. Also makes and uploads the zip files. Exceptions: Not just one class, this is the .cs file where I have all of my exception classes. Report: Builds and sends the report. Program: The main class for running the program. I recognize that the DataHandler class is a god object, but I don't have a good idea of how to refactor it. I feel like it should be more fine-grained than just breaking it into Sharepoint, Zip, and Upload, but maybe that's it. Also, I haven't yet worked out how to combine the periodic behavior with the "wait for user input at any point in the process" part; I think that involves threads, which means other classes to manage the threads... I'm not that well-versed in design patterns, but is there one that fits this project well? If this is too big of a topic to neatly explain in an SO answer, I'll also accept a link to a good tutorial on what I'm trying to do here.

    Read the article

< Previous Page | 111 112 113 114 115 116 117 118 119 120 121 122  | Next Page >