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  • Override methods should call base method?

    - by Trevor Pilley
    I'm just running NDepend against some code that I have written and one of the warnings is Overrides of Method() should call base.Method(). The places this occurs are where I have a base class which has virtual properties and methods with default behaviour but which can be overridden by a class which inherits from the base class and doesn't call the overridden method. For example, in the base class I have a property defined like this: protected virtual char CloseQuote { get { return '"'; } } And then in an inheriting class which uses a different close quote: protected override char CloseQuote { get { return ']'; } } Not all classes which inherit from the base class use different quote characters hence my initial design. The alternatives I thought of were have get/set properties in the base class with the defaults set in the constructor: protected BaseClass() { this.CloseQuote = '"'; } protected char CloseQuote { get; set; } public InheritingClass() { this.CloseQuote = ']'; } Or make the base class require the values as constructor args: protected BaseClass(char closeQuote, ...) { this.CloseQuote = '"'; } protected char CloseQuote { get; private set; } public InheritingClass() base (closeQuote: ']', ...) { } Should I use virtual in a scenario where the base implementation may be replaced instead of extended or should I opt for one of the alternatives I thought of? If so, which would be preferable and why?

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  • Did I Inadvertently Create a Mediator in my MVC?

    - by SoulBeaver
    I'm currently working on my first biggish project. It's a frontend facebook application that has, since last Tuesday, spanned some 6000-8000 LOC. I say this because I'm using the MVC, an architecture I have never rigidly enforced in any of my hobby projects. I read part of the PureMVC book, but I didn't quite grasp the concept of the Mediator. Since I didn't understand and didn't see the need for it, my project has yet to use a single mediator. Yesterday I went back to the design board because of some requirement changes and noticed that I could move all UI elements out of the View and into its own class. The View essentially only managed the lifetime of the UI and all events from the UI or Model. Technically, the View has now become a 'Mediator' between the Model and UI. Therefore, I realized today, I could just move all my UI stuff back into the View and create a mediator class that handles all events from the view and model. Is my understanding correct in thinking that I have devolved my View as it currently is (handling events from the Model and UI) into a Mediator and that the UI class is what should be the View?

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  • How to pass dynamic information between a form and a service? [closed]

    - by qminator
    I have a design problem and hopefully the braintrust which is stack exchange can help. I have a generic form, which loads a dataset and displays it. It never has direct knowledge of what it contains but can pass it to a service for manipulation (via an Onclick event for example). However, the form might need to alter its behaviour based on the manipulation by the service. Example: The service realises this dataset requires sending of an email by the user and needs to send an instruction to the form to open up a mail form. My idea is thus: I'm thinking about passing back some type of key/name dictionary, filled with commands which the service requires. They could then be interpeted by the form without it need to reference something specific. Example: IF the service decides that the dataset needs to refresh it would send back a key/name pair, I might even be able to chain commands. Refreshing the dataset and sending a mail. Refresh / "Foo" Mail / "[email protected]" The form would reference an action explicitly (Refresh or Mail) but not the instructions themselves. Is this a valid idea or am I wasting time?

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  • Motivation for a service layer (instead of just copying dlls)?

    - by BornToCode
    I'm creating an application which has 2 different UIs so I'm making it with a service layer which I understood is appropriate for such scenario. However I found myself just creating web methods for every single method I have in the BL layer, so the services basically built from methods that looks like this: return customers_bl.Get_Customer_Prices(customer_id); I understood that a main point of the service layer is to prevent duplication of code so I asked myself - why not just import the BL.DLL (and the dal.dll) to the other UI, and whenever making a change re-copy the dlls, it might not be so 'neat', but still less hassle than one more layer? {I know something is wrong in my approach, I'm probably missing the importance of service layer, I'd like to get more motivation to create another layer, especially because as it is I found that many of my BL functions ALREADY looks like: return customers_dal.Get_Customer_Prices(cust_id) which led me to ask: was it really necessary to create the BL just because on several functions I actually have LOGIC inside the BL?} so I'm looking for more motivation to creating ONE MORE layer, I'm sure it's not just to make it more convenient that I won't have to re-copy the dlls on changes? Am I grasping it wrong? Any simple guidelines on how to design service layer (corresponding to all the BL layer functions or not? any simple example?) any enlightenment on the subject?

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  • How to avoid the GameManager god object?

    - by lorancou
    I just read an answer to a question about structuring game code. It made me wonder about the ubiquitous GameManager class, and how it often becomes an issue in a production environment. Let me describe this. First, there's prototyping. Nobody cares about writing great code, we just try to get something running to see if the gameplay adds up. Then there's a greenlight, and in an effort to clean things up, somebody writes a GameManager. Probably to hold a bunch of GameStates, maybe to store a few GameObjects, nothing big, really. A cute, little, manager. In the peaceful realm of pre-production, the game is shaping up nicely. Coders have proper nights of sleep and plenty of ideas to architecture the thing with Great Design Patterns. Then production starts and soon, of course, there is crunch time. Balanced diet is long gone, the bug tracker is cracking with issues, people are stressed and the game has to be released yesterday. At that point, usually, the GameManager is a real big mess (to stay polite). The reason for that is simple. After all, when writing a game, well... all the source code is actually here to manage the game. It's easy to just add this little extra feature or bugfix in the GameManager, where everything else is already stored anyway. When time becomes an issue, no way to write a separate class, or to split this giant manager into sub-managers. Of course this is a classical anti-pattern: the god object. It's a bad thing, a pain to merge, a pain to maintain, a pain to understand, a pain to transform. What would you suggest to prevent this from happening?

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  • Which are the best ways to organize view hierarchies in GUI interfaces?

    - by none
    I'm currently trying to figure out the best techniques for organizing GUI view hierarchies, that is dividing a window into several panels which are in turn divided into other components. I've given a look to the Composite Design Pattern, but I don't know if I can find better alternatives, so I'd appreciate to know if using the Composite is a good idea, or it would be better looking for some other techniques. I'm currently developing in Java Swing, but I don't think that the framework or the language can have a great impact on this. Any help will be appreciated. ---------EDIT------------ I was currently developing a frame containing three labels, one button and a text field. At the button pressed, the content inside the text field would be searched, and the results written inside the three labels. One of my typical structure would be the following: MainWindow | Main panel | Panel with text field and labels. | Panel with search button Now, as the title explains, I was looking for a suitable way of organizing both the MainPanel and the other two panels. But here came problems, since I'm not sure whether organizing them like attributes or storing inside some data structure (i.e. LinkedList or something like this). Anyway, I don't really think that both my solution are really good, so I'm wondering if there are really better approaches for facing this kind of problems. Hope it helps

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  • Should sanity be a property of a programmer or a program?

    - by toplel32
    I design and implement languages, that can range from object notations to markup languages. In many cases I have considered restrictions in favor of sanity (common knowledge), like in the case of control characters in identifiers. There are two consequences to consider before doing this: It takes extra computation It narrows liberty I'm interested to learn how developers think of decisions like this. As you may know Microsoft C# is very open on the contrary. If you really want to prefix your integer as Long with 'l' instead of 'L' and so risk other developers of confusing '1' and 'l', no problem. If you want to name your variables in non-latin script so they will contrast with C#'s latin keywords, no problem. Or if you want to distribute a string over multiple lines and so break a series of indentation, no problem. It is cheap to ensure consistency with restrictions and this makes it tempting to implement. But in the case of disallowing non-latin characters (concerning the second example), it means a discredit to Unicode, because one would not take full advantage of its capacity.

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  • On Developing Web Services with Global State

    - by user74418
    I'm new to web programming. I'm more experienced and comfortable with client-side code. Recently, I've been dabbling in web programming through Python's Google App Engine. I ran into some difficulty while trying to write some simple apps for the purposes of learning, mainly involving how to maintain some kind of consistent universally-accessible state for the application. I tried to write a simple queueing management system, the kind you would expect to be used in a small clinic, or at a cafeteria. Typically, this is done with hardware. You take a number from a ticketing machine, and when your number is displayed or called you approach the counter for service. Alternatively, you could be given a small pager, which will beep or vibrate when it is your turn to receive service. The former is somewhat better in that you have an idea of how many people are still ahead of you in the queue. In this situation, the global state is the last number in queue, which needs to be updated whenever a request is made to the server. I'm not sure how to best to store and maintain this value in a GAE context. The solution I thought of was to keep the value in the Datastore, attempt to query it during a ticket request, update the value, and then re-store it with put. My problem is that I haven't figured out how to lock the resource so that other requests do not check the value while it is in the middle of being updated. I am concerned that I may end up ticket requests that have the same queue number. Also, the whole solution feels awkward to me. I was wondering if there was a more natural way to accomplish this without having to go through the Datastore. Can anyone with more experience in this domain provide some advice on how to approach the design of the above application?

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  • Getting Requirements Right

    - by Tim Murphy
    Originally posted on: http://geekswithblogs.net/tmurphy/archive/2013/10/28/getting-requirements-right.aspxI had a meeting with a stakeholder who stated “I bet you wish I wasn’t in these meetings”.  She said this because she kept changing what we thought the end product should look like.  My reply was that it would be much worse if she came in at the end of the project and told us we had just built the wrong solution. You have to take the time to get the requirements right.  Be honest with all involved parties as to the amount of time it is taking to refine the requirements.  The only thing worse than wrong requirements is a surprise in budget overages.  If you give open visibility to your progress then management has the ability to shift priorities if needed. In order to capture the best requirements use different approaches to help your stakeholders to articulate their needs.  Use mock ups and matrix spread sheets to allow them to visualize and confirm that everyone has the same understanding.  The goals isn’t to record every last detail, but to have the major landmarks identified so there are fewer surprises along the way. Help the team members to understand that you all have the same goal.  You want to create the best possible solution for the given business problem.  If you do this everyone involved will do there best to outline a picture of what is to be built and you will be able to design an appropriate solution to fill those needs more easily. Technorati Tags: requirements gathering,PSC Group,PSC

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  • Redesigning my website has destroyed my SEO

    - by user20721
    Unfortunately i read an article on how to avoid destroying your websites SEO from a redesign article AFTER its was too late! Here is the article (http://www.searchenginejournal.com/how-to-avoid-seo-disaster-during-a-website-redesign/42824/) On 20 November 12 completely redesigned our www.retromodern.com.au . We get ALL our customers from our website as we do not have a shop. Since that dreaded day a month ago the phone pretty much stopped, basically no emails, Google rankings down and Google analytics have halved by 50%. Yesterday i did some research into as as i had no idea that a re-design of a website could have such a damaging effect - yes i am a novice and use a WYSIWYG type web builder. There are lots of info on how to AVOID this from happening BUT what do i do as i have already made the mistake? Yesterday i reloaded my OLD site with my new pages in the background hoping this would be a start. I really have no idea of how to get out of this mess. Please please help. Thanks in Advance. Monique

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  • Hide or Show singleton?

    - by Sinker
    Singleton is a common pattern implemented in both native libraries of .NET and Java. You will see it as such: C#: MyClass.Instance Java: MyClass.getInstance() The question is: when writing APIs, is it better to expose the singleton through a property or getter, or should I hide it as much as possible? Here are the alternatives for illustrative purposes: Exposed(C#): private static MyClass instance; public static MyClass Instance { get { if (instance == null) instance = new MyClass(); return instance; } } public void PerformOperation() { ... } Hidden (C#): private static MyClass instance; public static void PerformOperation() { if (instance == null) { instance = new MyClass(); } ... } EDIT: There seems to be a number of detractors of the Singleton design. Great! Please tell me why and what is the better alternative. Here is my scenario: My whole application utilises one logger (log4net/log4j). Whenever, the program has something to log, it utilises the Logger class (e.g. Logger.Instance.Warn(...) or Logger.Instance.Error(...) etc. Should I use Logger.Warn(...) or Logger.Warn(...) instead? If you have an alternative to singletons that addresses my concern, then please write an answer for it. Thank you :)

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  • How should I implement Transaction database EJB 3.0

    - by JamesBoyZ
    In the CustomerTransactions entity, I have the following field to record what the customer bought: @ManyToMany private List<Item> listOfItemsBought; When I think more about this field, there's a chance it may not work because merchants are allowed to change item's information (e.g. price, discount, etc...). Hence, this field will not be able to record what the customer actually bought when the transaction occurred. At the moment, I can only think of 2 ways to make it work. I will record the transaction details into a String field. I feel that this way would be messy if I need to extract some information about the transaction later on. Whenever the merchant changes an item's information, I will not update directly to that item's fields. Instead, I will create another new item with all the new information and keep the old item untouched. I feel that this way is better because I can easily extract information about the transaction later on. However, the bad side is that my Item table may contain a lot of rows. I'd be very grateful if someone could give me an advice on how I should tackle this problem. UPDATE: I'd like to add more information about the current design. public class Customer implements Serializable { @OneToMany private List<CustomerTransactions> listOfTransactions; } public class CustomerTransactions implements Serializable { @ManyToMany private List<Item> listOfItemsBought; } public class Merchant implements Serializable { @OneToMany private List<Item> listOfSellingItems; }

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  • Why using Fragments?

    - by ahmed_khan_89
    I have read the documentation and some other questions' threads about this topic and I don't really feel convinced; I don't see clearly the limits of use of this technique. Fragments are now seen as a Best Practice; every Activity should be basically a support for one or more Fragments and not call a layout directly. Fragments are created in order to: allow the Activity to use many fragments, to change between them, to reuse these units... == the Fragment is totally dependent to the Context of an activity , so if I need something generic that I can reuse and handle in many Activities, I can create my own custom layouts or Views ... I will not care about this additional Complexity Developing Layer that fragments would add. a better handling to different resolution == OK for tablets/phones in case of long process that we can show two (or more) fragments in the same Activity in Tablets, and one by one in phones. But why would I use fragments always ? handling callbacks to navigate between Fragments (i.e: if the user is Logged-in I show a fragment else I show another fragment). === Just try to see how many bugs facebook SDK Log-in have because of this, to understand that it is really (?) ... considering that an Android Application is based on Activities... Adding another life cycles in the Activity would be better to design an Application... I mean the modules, the scenarios, the data management and the connectivity would be better designed, in that way. === This is an answer of someone who's used to see the Android SDK and Android Framework with a Fragments vision. I don't think it's wrong, but I am not sure it will give good results... And it is really abstract... ==== Why would I complicate my life, coding more, in using them always? else, why is it a best practice if it's just a tool for some cases? what are these cases?

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  • Replacing “if”s with your own number system

    - by Michael Williamson
    During our second code retreat at Red Gate, the restriction for one of the sessions was disallowing the use of if statements. That includes other constructs that have the same effect, such as switch statements or loops that will only be executed zero or one times. The idea is to encourage use of polymorphism instead, and see just how far it can be used to get rid of “if”s. The main place where people struggled to get rid of numbers from their implementation of Conway’s Game of Life was the piece of code that decides whether a cell is live or dead in the next generation. For instance, for a cell that’s currently live, the code might look something like this: if (numberOfNeighbours == 2 || numberOfNeighbours == 3) { return CellState.LIVE; } else { return CellState.DEAD; } The problem is that we need to change behaviour depending on the number of neighbours each cell has, but polymorphism only allows us to switch behaviour based on the type of a value. It follows that the solution is to make different numbers have different types: public interface IConwayNumber { IConwayNumber Increment(); CellState LiveCellNextGeneration(); } public class Zero : IConwayNumber { public IConwayNumber Increment() { return new One(); } public CellState LiveCellNextGeneration() { return CellState.DEAD; } } public class One : IConwayNumber { public IConwayNumber Increment() { return new Two(); } public CellState LiveCellNextGeneration() { return CellState.LIVE; } } public class Two : IConwayNumber { public IConwayNumber Increment() { return new ThreeOrMore(); } public CellState LiveCellNextGeneration() { return CellState.LIVE; } } public class ThreeOrMore : IConwayNumber { public IConwayNumber Increment() { return this; } public CellState LiveCellNextGeneration() { return CellState.DEAD; } } In the code that counts the number of neighbours, we use our new number system by starting with Zero and incrementing when we find a neighbour. To choose the next state of the cell, rather than inspecting the number of neighbours, we ask the number of neighbours for the next state directly: return numberOfNeighbours.LiveCellNextGeneration(); And now we have no “if”s! If C# had double-dispatch, or if we used the visitor pattern, we could move the logic for choosing the next cell out of the number classes, which might feel a bit more natural. I suspect that reimplementing the natural numbers is still going to feel about the same amount of crazy though.

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  • Best Practice for Software Maintenance Console

    - by Ben-G
    I am looking for a list of must-have maintenance/administration features/components/services for enterprise applications. I know following common components: Configuration Cockpit (shows current configuration mistakes/issues) Load-Analysis (shows the current load on different system components) Vitality measures Log File Access System Restart Capability Backup/Restore Capability Are there any widely accepted services/features which are included in any software with a focus on reliablity and maintainability?

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  • Package system broken - E: Sub-process /usr/bin/dpkg returned an error code (1)

    - by delha
    After installing some packages and libraries I have an error on Package Manager, I can't run any update because it says: "The package system is broken If you are using third party repositories then disable them, since they are a common source of problems. Now run the following command in a terminal: apt-get install -f " I've tried to do what it says and it returns me: jara@jara-Aspire-5738:~$ sudo apt-get install -f Reading package lists... Done Building dependency tree Reading state information... Done Correcting dependencies... Done The following packages were automatically installed and are no longer required: libcaca-dev libopencv2.3-bin nite-dev python-bluez ps-engine libslang2-dev python-sphinx ros-electric-geometry-tutorials ros-electric-geometry-visualization python-matplotlib libzzip-dev ros-electric-orocos-kinematics-dynamics ros-electric-physics-ode libbluetooth-dev libaudiofile-dev libassimp2 libnetpbm10-dev ros-electric-laser-pipeline python-epydoc ros-electric-geometry-experimental libasound2-dev evtest python-matplotlib-data libyaml-dev ros-electric-bullet ros-electric-executive-smach ros-electric-documentation libgl2ps0 libncurses5-dev ros-electric-robot-model texlive-fonts-recommended python-lxml libwxgtk2.8-dev daemontools libxxf86vm-dev libqhull-dev libavahi-client-dev ros-electric-geometry libgl2ps-dev libcurl4-openssl-dev assimp-dev libusb-1.0-0-dev libopencv2.3 ros-electric-diagnostics-monitors libsdl1.2-dev libjs-underscore libsdl-image1.2 tipa libusb-dev libtinfo-dev python-tz python-sip libfltk1.1 libesd0 libfreeimage-dev ros-electric-visualization x11proto-xf86vidmode-dev python-docutils libvtk5.6 ros-electric-assimp x11proto-scrnsaver-dev libnetcdf-dev libidn11-dev libeigen3-dev joystick libhdf5-serial-1.8.4 ros-electric-joystick-drivers texlive-fonts-recommended-doc esound-common libesd0-dev tcl8.5-dev ros-electric-multimaster-experimental ros-electric-rx libaudio-dev ros-electric-ros-tutorials libwxbase2.8-dev ros-electric-visualization-common python-sip-dev ros-electric-visualization-tutorials libfltk1.1-dev libpulse-dev libnetpbm10 python-markupsafe openni-dev tk8.5-dev wx2.8-headers freeglut3-dev libavahi-common-dev python-roman python-jinja2 ros-electric-robot-model-visualization libxss-dev libqhull5 libaa1-dev ros-electric-eigen freeglut3 ros-electric-executive-smach-visualization ros-electric-common-tutorials ros-electric-robot-model-tutorials libnetcdf6 libjs-sphinxdoc python-pyparsing libaudiofile0 Use 'apt-get autoremove' to remove them. The following extra packages will be installed: libcv-dev The following NEW packages will be installed libcv-dev 0 upgraded, 1 newly installed, 0 to remove and 4 not upgraded. 2 not fully installed or removed. Need to get 0 B/3,114 kB of archives. After this operation, 11.1 MB of additional disk space will be used. Do you want to continue [Y/n]? y (Reading database ... 261801 files and directories currently installed.) Unpacking libcv-dev (from .../libcv-dev_2.1.0-7build1_amd64.deb) ... dpkg: error processing /var/cache/apt/archives/libcv-dev_2.1.0-7build1_amd64.deb (-- unpack): trying to overwrite '/usr/bin/opencv_haartraining', which is also in package libopencv2.3-bin 2.3.1+svn6514+branch23-12~oneiric dpkg-deb: error: subprocess paste was killed by signal (Broken pipe) Errors were encountered while processing: /var/cache/apt/archives/libcv-dev_2.1.0-7build1_amd64.deb E: Sub-process /usr/bin/dpkg returned an error code (1) I've tried everything people recommend on internet like: sudo apt-get clean sudo apt-get autoremove sudo apt-get update sudo apt-get upgrade sudo apt-get -f install Also I've tried to install the synaptic manager but it doesn't let me install anything.. As you can see nothing works so I'm desperate! I'm using ubuntu 11.10, 64 bits Thanks!!

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  • State / Screen management in Entity Component Systems

    - by David Lively
    My entity/component system is happily humming along and, despite some performance concerns I initially had, everything is working fine. However, I've realized that I missed a crucial point when starting this thing: how do you handle different screens? At the moment, I have a GameManager class which owns a component manager and entity manager. When I create an entity, the entity manager assigns it an ID and makes sure it's tracked. When I modify the components that are assigned to an entity. an UpdateEntity method is called, which alerts each of the systems that they may need to add or remove the entity from their respective entity lists. A problem with this is that the collection of entities operated on by each system is determined solely by the individual Systems, typically based on a "required component" filter. (An entity has to have a Renderable component to be rendered, for instance.) In this situation, I can't just keep collections of entities per screen and only Update/Draw those collections. They'd have to either be added and removed depending on their applicability to the current screen, which would cause their associated components to be removed, or enable/disable entities in a group per screen to hide what's not supposed to be visible. These approaches seem like really, really crappy kludges. What's a good way to handle this? A pretty straightforward way that comes to mind is to create a separate GameManager (which in my implementation owns all of the systems, entities, etc.) per screen, which means that everything outside of the device context would be duplicated. That's bothersome because some things are always visible, or I might want to continue to display the game under a translucent menu window. Another option would be to add a "layer" key to the GameManager class, which could be checked against a displayable layer stack held by the game manager. *System.Draw() would be called for each active layer, in the required order as determined by the stack. When the systems request an iterator for their respective entity collections, it would be pre-filtered to a (cached) set of those entities that participate in the active layer. Those collections could be updated from the same UpdateEntity event that's already used to maintain each system's entity collections. Still, kinda feels like a hack. If I've coded myself into a corner, feel free to throw tomatoes as long as they're labeled with a helpful suggestion. Hooray for learning curves.

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  • Unable to acces sound settings

    - by Dumitru Cristian
    I’m unable to access the sound settings in U1404 TT. Before updating to Ubuntu 14.04, with right click and System setting I had access to some settings which allowed me to set different sound levels for different application. Now I'm unable to do that. Click on Sound settings send me to a Setting window where sound settings are not available. Actually, as you can see, my system settings menu is quite reduced (no options for keyboard).

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  • How do I find out which boot loader I have?

    - by binW
    I know Grub is the one installed by default when installing Ubuntu but I am faced with an embedded system running 9.10 Desktop Edition. Following are the contents of lsb-release file ubuntu@ubuntu-desktop:/boot$ cat /etc/lsb-release DISTRIB_ID=Ubuntu DISTRIB_RELEASE=9.10 DISTRIB_CODENAME=karmic DISTRIB_DESCRIPTION="Ubuntu 9.10" but this system does not have Grub bootloader and I want to find out which one its using. So any ideas?

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  • Is Grub installed when Ubuntu is the only OS installed?

    - by Dennis
    I have a simple question concerning Grub. When Ubuntu it's the only system installed on a machine, Grub doesn't appear when the computer it's turned on, my question is: When Ubuntu is the only system, Grub it's not installed on MBR? I has this doubt when I tried the ASPM command in Grub, to see if it could save some battery on my notebook, and the difference was only 0.4W. I don't even know if it made some effect or it's just a normal oscilation. Thanks.

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  • Particle System in XNA - cannot draw particle

    - by Dave Voyles
    I'm trying to implement a simple particle system in my XNA project. I'm going by RB Whitaker's tutorial, and it seems simple enough. I'm trying to draw particles within my menu screen. Below I've included the code which I think is applicable. I'm coming up with one error in my build, and it is stating that I need to create a new instance of the EmitterLocation from the particleEngine. When I hover over particleEngine.EmitterLocation = new Vector2(Mouse.GetState().X, Mouse.GetState().Y); it states that particleEngine is returning a null value. What could be causing this? /// <summary> /// Base class for screens that contain a menu of options. The user can /// move up and down to select an entry, or cancel to back out of the screen. /// </summary> abstract class MenuScreen : GameScreen ParticleEngine particleEngine; public void LoadContent(ContentManager content) { if (content == null) { content = new ContentManager(ScreenManager.Game.Services, "Content"); } base.LoadContent(); List<Texture2D> textures = new List<Texture2D>(); textures.Add(content.Load<Texture2D>(@"gfx/circle")); textures.Add(content.Load<Texture2D>(@"gfx/star")); textures.Add(content.Load<Texture2D>(@"gfx/diamond")); particleEngine = new ParticleEngine(textures, new Vector2(400, 240)); } public override void Update(GameTime gameTime, bool otherScreenHasFocus, bool coveredByOtherScreen) { base.Update(gameTime, otherScreenHasFocus, coveredByOtherScreen); // Update each nested MenuEntry object. for (int i = 0; i < menuEntries.Count; i++) { bool isSelected = IsActive && (i == selectedEntry); menuEntries[i].Update(this, isSelected, gameTime); } particleEngine.EmitterLocation = new Vector2(Mouse.GetState().X, Mouse.GetState().Y); particleEngine.Update(); } public override void Draw(GameTime gameTime) { // make sure our entries are in the right place before we draw them UpdateMenuEntryLocations(); GraphicsDevice graphics = ScreenManager.GraphicsDevice; SpriteBatch spriteBatch = ScreenManager.SpriteBatch; SpriteFont font = ScreenManager.Font; spriteBatch.Begin(); // Draw stuff logic spriteBatch.End(); particleEngine.Draw(spriteBatch); }

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  • TreeView in Winforms and focus problem

    - by Marcus
    Hi, Can anyone please explain to my why the form in the code below gets out of focus when selecting a treenode in the tree? What should happen is that the form/button should get the focus when the tree disappears like the listview example but it doesn't. Code example: using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Text; using System.Windows.Forms; namespace FocusTest { public partial class Form1 : Form { #region Generated /// <summary> /// Required designer variable. /// </summary> private System.ComponentModel.IContainer components = null; /// <summary> /// Clean up any resources being used. /// </summary> /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param> protected override void Dispose(bool disposing) { if (disposing && (components != null)) { components.Dispose(); } base.Dispose(disposing); } #region Windows Form Designer generated code /// <summary> /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// </summary> private void InitializeComponent() { System.Windows.Forms.ListViewItem listViewItem1 = new System.Windows.Forms.ListViewItem("Item1"); System.Windows.Forms.ListViewItem listViewItem2 = new System.Windows.Forms.ListViewItem("Item2"); System.Windows.Forms.ListViewItem listViewItem3 = new System.Windows.Forms.ListViewItem("Item3"); System.Windows.Forms.TreeNode treeNode1 = new System.Windows.Forms.TreeNode("Node0"); System.Windows.Forms.TreeNode treeNode2 = new System.Windows.Forms.TreeNode("Node1"); System.Windows.Forms.TreeNode treeNode3 = new System.Windows.Forms.TreeNode("Node2"); this.button1 = new System.Windows.Forms.Button(); this.listView1 = new System.Windows.Forms.ListView(); this.button2 = new System.Windows.Forms.Button(); this.treeView1 = new System.Windows.Forms.TreeView(); this.SuspendLayout(); // // button1 // this.button1.Location = new System.Drawing.Point(12, 12); this.button1.Name = "button1"; this.button1.Size = new System.Drawing.Size(75, 23); this.button1.TabIndex = 0; this.button1.Text = "button1"; this.button1.UseVisualStyleBackColor = true; this.button1.Click += new System.EventHandler(this.button1_Click); // // listView1 // this.listView1.Items.AddRange(new System.Windows.Forms.ListViewItem[] { listViewItem1, listViewItem2, listViewItem3 }); this.listView1.Location = new System.Drawing.Point(12, 41); this.listView1.Name = "listView1"; this.listView1.Size = new System.Drawing.Size(121, 97); this.listView1.TabIndex = 1; this.listView1.UseCompatibleStateImageBehavior = false; this.listView1.Visible = false; this.listView1.SelectedIndexChanged += new System.EventHandler(this.listView1_SelectedIndexChanged); this.listView1.View = View.List; // // button2 // this.button2.Location = new System.Drawing.Point(310, 11); this.button2.Name = "button2"; this.button2.Size = new System.Drawing.Size(75, 23); this.button2.TabIndex = 2; this.button2.Text = "button2"; this.button2.UseVisualStyleBackColor = true; this.button2.Click += new System.EventHandler(this.button2_Click); // // treeView1 // this.treeView1.Location = new System.Drawing.Point(310, 41); this.treeView1.Name = "treeView1"; treeNode1.Name = "Node0"; treeNode1.Text = "Node0"; treeNode2.Name = "Node1"; treeNode2.Text = "Node1"; treeNode3.Name = "Node2"; treeNode3.Text = "Node2"; this.treeView1.Nodes.AddRange(new System.Windows.Forms.TreeNode[] { treeNode1, treeNode2, treeNode3}); this.treeView1.Size = new System.Drawing.Size(121, 97); this.treeView1.TabIndex = 3; this.treeView1.Visible = false; this.treeView1.AfterSelect += new System.Windows.Forms.TreeViewEventHandler(this.treeView1_AfterSelect); // // Form1 // this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F); this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; this.ClientSize = new System.Drawing.Size(760, 409); this.Controls.Add(this.treeView1); this.Controls.Add(this.button2); this.Controls.Add(this.listView1); this.Controls.Add(this.button1); this.Name = "Form1"; this.Text = "Form1"; this.ResumeLayout(false); } #endregion private System.Windows.Forms.Button button1; private System.Windows.Forms.ListView listView1; private System.Windows.Forms.Button button2; private System.Windows.Forms.TreeView treeView1; #endregion public Form1() { InitializeComponent(); } #region TreeView private void button2_Click(object sender, EventArgs e) { ToggleTreeView(); } private void ToggleTreeView() { if (treeView1.Visible) { Controls.Remove(treeView1); treeView1.Visible = false; } else { Controls.Add(treeView1); treeView1.Size = new Size(300, 400); treeView1.Location = PointToClient(PointToScreen(new System.Drawing.Point(button2.Location.X, button2.Location.Y + button2.Height))); this.treeView1.BringToFront(); treeView1.Visible = true; treeView1.Select(); } } private void treeView1_AfterSelect(object sender, TreeViewEventArgs e) { ToggleTreeView(); } #endregion #region ListView private void button1_Click(object sender, EventArgs e) { ToggleListView(); } private void ToggleListView() { if (listView1.Visible) { Controls.Remove(listView1); listView1.Visible = false; } else { Controls.Add(listView1); listView1.Size = new Size(300, 400); listView1.Location = PointToClient(PointToScreen(new System.Drawing.Point(button1.Location.X, button1.Location.Y + button1.Height))); this.listView1.BringToFront(); listView1.Visible = true; listView1.Select(); } } private void listView1_SelectedIndexChanged(object sender, EventArgs e) { if (listView1.Visible) ToggleListView(); } #endregion } }

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  • IIS 7.5 Manager crashes when adding a custom error page

    - by dig412
    I'm running a local IIS 7.5 server in Win 7 Pro, and I'm trying to add a custom error page for 403 responses. When I click OK to add a custom error page for my site, IIS Manager just vanishes. The server is still running, and I can re-start IIS Manager, but the new page has not been saved. I've also tried adding it directly to web.config, but that just gives me The page cannot be displayed because an internal server error has occurred. Does anyone know why this might be happening? Edit: The event log implies that an invalid character in the path caused the crash, but It occured even when I copied & pasted a path from a valid entry. Application error log: IISMANAGER_CRASH IIS Manager terminated unexpectedly. Exception:System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. --- System.ArgumentException: Illegal characters in path. at System.IO.Path.CheckInvalidPathChars(String path) at System.IO.Path.IsPathRooted(String path) at Microsoft.Web.Management.Iis.CustomErrors.CustomErrorsForm.OnAccept() at Microsoft.Web.Management.Client.Win32.TaskForm.OnOKButtonClick(Object sender, EventArgs e) at System.Windows.Forms.Control.OnClick(EventArgs e) at System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent) at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ButtonBase.WndProc(Message& m) at System.Windows.Forms.Button.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context) at System.Windows.Forms.Form.ShowDialog(IWin32Window owner) at Microsoft.Web.Management.Host.UserInterface.ManagementUIService.ShowDialogInternal(Form form, IWin32Window parent) at Microsoft.Web.Management.Host.UserInterface.ManagementUIService.Microsoft.Web.Management.Client.Win32.IManagementUIService.ShowDialog(DialogForm form) at Microsoft.Web.Management.Client.Win32.ModulePage.ShowDialog(DialogForm form) at Microsoft.Web.Management.Iis.CustomErrors.CustomErrorsPage.AddCustomError() --- End of inner exception stack trace --- at System.RuntimeMethodHandle._InvokeMethodFast(Object target, Object[] arguments, SignatureStruct& sig, MethodAttributes methodAttributes, RuntimeTypeHandle typeOwner) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at Microsoft.Web.Management.Client.TaskList.InvokeMethod(String methodName, Object userData) at Microsoft.Web.Management.Host.UserInterface.Tasks.MethodTaskItemLine.InvokeMethod() at System.Windows.Forms.LinkLabel.OnMouseUp(MouseEventArgs e) at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.Label.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg) at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context) at Microsoft.Web.Management.Host.Shell.ShellApplication.Execute(Boolean localDevelopmentMode, Boolean resetPreferences, Boolean resetPreferencesNoLaunch) Process:InetMgr

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  • I can't update my system properly, "no package header" error

    - by joel
    Every time I try to run sudo apt-get update or try running updates from the GUI interface I run into the following problem or something similar: Reading package lists... Error! E: Encountered a section with no Package: header E: Problem with MergeList /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_precise_restricted_binary-i386_Packages E: The package lists or status file could not be parsed or opened. I've tried purging using sudo rm -rf <filename> where <filename> is the listed file above, and then running sudo apt-get update to fix it (as listed elsewhere in this forum) and no luck, just keep getting this message. I'm running Ubuntu 12.04 and this is getting really frustrating... I just want a system that runs smoothly and doesn't require it's hand to be held when it comes to updates. Tried the solutions posted below and am still receiving the same errors, sample output: W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise_main_binary-amd64_Packages Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise_main_binary-i386_Packages Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise_restricted_binary-i386_Packages Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise_universe_binary-i386_Packages Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise_multiverse_binary-i386_Packages Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-updates_universe_source_Sources Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-updates_restricted_binary-i386_Packages Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-updates_universe_binary-i386_Packages Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-updates_multiverse_binary-i386_Packages Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-backports_universe_binary-i386_Packages Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-security_main_source_Sources Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-security_universe_binary-amd64_Packages Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-security_main_binary-i386_Packages Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-security_universe_binary-i386_Packages Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise_main_i18n_Translation-en%5fCA Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-updates_main_i18n_Translation-en%5fCA Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-updates_main_i18n_Translation-en Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-updates_multiverse_i18n_Translation-en%5fCA Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-updates_universe_i18n_Translation-en%5fCA Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-backports_main_i18n_Translation-en%5fCA Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-backports_multiverse_i18n_Translation-en%5fCA Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-backports_universe_i18n_Translation-en%5fCA Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-security_main_i18n_Translation-en%5fCA Encountered a section with no Package: header W: Failed to fetch gzip:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_precise-security_multiverse_i18n_Translation-en%5fCA Encountered a section with no Package: header E: Some index files failed to download. They have been ignored, or old ones used instead.

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  • Improving performance of a particle system (OpenGL ES)

    - by Jason
    I'm in the process of implementing a simple particle system for a 2D mobile game (using OpenGL ES 2.0). It's working, but it's pretty slow. I start getting frame rate battering after about 400 particles, which I think is pretty low. Here's a summary of my approach: I start with point sprites (GL_POINTS) rendered in a batch just using a native float buffer (I'm in Java-land on Android, so that translates as a java.nio.FloatBuffer). On GL context init, the following are set: GLES20.glViewport(0, 0, width, height); GLES20.glClearColor(0.0f, 0.0f, 0.0f, 0.0f); GLES20.glEnable(GLES20.GL_CULL_FACE); GLES20.glDisable(GLES20.GL_DEPTH_TEST); Each draw frame sets the following: GLES20.glEnable(GLES20.GL_BLEND); GLES20.glBlendFunc(GLES20.GL_ONE, GLES20.GL_ONE_MINUS_SRC_ALPHA); And I bind a single texture: GLES20.glActiveTexture(GLES20.GL_TEXTURE0); GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandle); GLES20.glUniform1i(mUniformTextureHandle, 0); Which is just a simple circle with some blur (and hence some transparency) http://cl.ly/image/0K2V2p2L1H2x Then there are a bunch of glVertexAttribPointer calls: mBuffer.position(position); mGlEs20.glVertexAttribPointer(mAttributeRGBHandle, valsPerRGB, GLES20.GL_FLOAT, false, stride, mBuffer); ...4 more of these Then I'm drawing: GLES20.glUniformMatrix4fv(mUniformProjectionMatrixHandle, 1, false, Camera.mProjectionMatrix, 0); GLES20.glDrawArrays(GLES20.GL_POINTS, 0, drawCalls); GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, 0); My vertex shader does have some computation in it, but given that they're point sprites (with only 2 coordinate values) I'm not sure this is the problem: #ifdef GL_ES // Set the default precision to low. precision lowp float; #endif uniform mat4 u_ProjectionMatrix; attribute vec4 a_Position; attribute float a_PointSize; attribute vec3 a_RGB; attribute float a_Alpha; attribute float a_Burn; varying vec4 v_Color; void main() { vec3 v_FGC = a_RGB * a_Alpha; v_Color = vec4(v_FGC.x, v_FGC.y, v_FGC.z, a_Alpha * (1.0 - a_Burn)); gl_PointSize = a_PointSize; gl_Position = u_ProjectionMatrix * a_Position; } My fragment shader couldn't really be simpler: #ifdef GL_ES // Set the default precision to low. precision lowp float; #endif uniform sampler2D u_Texture; varying vec4 v_Color; void main() { gl_FragColor = texture2D(u_Texture, gl_PointCoord) * v_Color; } That's about it. I had read that transparent pixels in point sprites can cause issues, but surely not at only 400 points? I'm running on a fairly new device (12 month old Galaxy Nexus). My question is less about my approach (although I'm open to suggestion) but more about whether there are any specific OpenGL "no no's" that have leaked into my code. I'm sure there's GL master out there facepalming right now... I'd love to hear any critique.

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