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• RIM's current BB7 developer toolset is a joke

  - by mbrit

  tl;dr - RIM's current developer toolset is not fit for purpose.Background to this is that I'm currently working on a PhoneGap/Cordova project for a client that has to run on BlackBerry. The tooling is so ridiculous to use that even though I had a gentle dig at them in a Guardian piece it's worth having a more full-on attack.At the moment, RIM's pitch is that apps are built for the current BBOS7 devices using WebWorks. This is an HTML-based toolset. Essentially a browser is spun up in a native app container and your app is powered by JavaScript. Specific JavaScript libraries exist that thunk down to native capabilities no the device. I happen to use PhoneCap/Cordova in combination with this.The tooling is non-existent. I'm using TextMate, Ant, and Terminal to develop the app. There's no "console.log" output, and no debugging. The only way to instrument the app is to put "alert" calls in your code.Apart from the fact that that's *not* fine in 2012, how about this… every time you deploy a new app to the device, the device has to reboot. This process takes six minutes on a relatively modern BlackBerry device. How about this as well - in order to get a file into the package it has to be signed. My small app over here has 100 different files (75 or so generated). Signing doesn't happen locally, it happens on RIM's servers in Waterloo. Thus whenever you deploy the app you have this utility have to call RIM's servers 100 times. More to the point, sometimes during the day these servers have "micro-downtime" moments where they're unreachable for five or ten minutes, normally two or three times a day. Oh yes, you'll also get an email sent to you per signing on success or failure. 100 inbound emails, per deployment.(I started this post at the beginning of one of these cycles, by the way. That's how long it takes to build and deploy *once*. By the way, the change I made didn't work.)To clarify:* Change the script,* Build it using Ant,* Ant will spin up a Java app that talks to RIM's servers to sign it.* Receive 100 emails, assuming the server is up.* App deployed - takes about 30 seconds.* BlackBerry device restarts - takes about six minutes.* Find and open the app. Go through security prompts.* Test the app, with no "console.log" output and no debugger."Why not use the simulator?" I hear you ask. Well, apart from the fact that the simulator refused to reach any network service over HTTPS that I happen to own? (Some people suggest changing DNS settings for this known issue.) Admittedly, the simulator does show you console.log, but you still have the "six minute" restart issue on the simulator.Developers will understand this problem. Breaking concentration for six-plus minutes every time you want to deploy an app turns developing into a nightmare. Combining that with no worthy debugging tools turns the toolset into a joke.

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• Mixing Forms and Token Authentication in a single ASP.NET Application

  - by Your DisplayName here!

  I recently had the task to find out how to mix ASP.NET Forms Authentication with WIF’s WS-Federation. The FormsAuth app did already exist, and a new sub-directory of this application should use ADFS for authentication. Minimum changes to the existing application code would be a plus ;) Since the application is using ASP.NET MVC this was quite easy to accomplish – WebForms would be a little harder, but still doable. I will discuss the MVC solution here. To solve this problem, I made the following changes to the standard MVC internet application template: Added WIF’s WSFederationAuthenticationModule and SessionAuthenticationModule to the modules section. Add a WIF configuration section to configure the trust with ADFS. Added a new authorization attribute. This attribute will go on controller that demand ADFS (or STS in general) authentication. The attribute logic is quite simple – it checks for authenticated users – and additionally that the authentication type is set to Federation. If that’s the case all is good, if not, the redirect to the STS will be triggered. public class RequireTokenAuthenticationAttribute : AuthorizeAttribute {     protected override bool AuthorizeCore(HttpContextBase httpContext)     {         if (httpContext.User.Identity.IsAuthenticated &&             httpContext.User.Identity.AuthenticationType.Equals( WIF.AuthenticationTypes.Federation, StringComparison.OrdinalIgnoreCase))         {             return true;         }                     return false;     }     protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)     {                    // do the redirect to the STS         var message = FederatedAuthentication.WSFederationAuthenticationModule.CreateSignInRequest( "passive", filterContext.HttpContext.Request.RawUrl, false);         filterContext.Result = new RedirectResult(message.RequestUrl);     } } That’s it ;) If you want to know why this works (and a possible gotcha) – read my next post.

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• Full disk encryption with seperate boot and encrypted keyfile storage: Two-Form Authentication

  - by Cain

  I am trying to setup true Full Disk encryption with two-form authentication on 12.04 and can not find out how to call a keyfile for the encrypted root out of another encrypted partition. All documentation or questions I am finding for whole or full disk encryption only encrypts separate partitions on the same disk. This is not what most are calling full disk encryption, /boot is not on a partition on the root drive, rather it is on a usb stick as sdx1. Instead root is on a logical partition on top of a LUKS container. Luks is run on the whole disk, encrypting the partition table as well. All drives in the machine are completely encrypted and to open it it requires a USB drive (what I have) as well as a passphrase (what I know) resulting in Two-Form Authentication to boot the machine. Device sdx cryptroot vg00 lvroot / There is no passphrase to open the encrypted root device, only a keyfile. That keyfile is kept on the usb drive with /boot, in its own encrypted partition (I'll call this cryptkey). In order for the root file system (cryptroot) to be opened, initramfs must ask for the passphrase to cryptkey on the usb drive, then use the keyfile inside that to open cryproot. I did manage to find what I think is the how-to I used to do this once before: http://wiki.ubuntu.org.cn/UbuntuHelp:FeistyLUKSTwoFormFactor I already have the system installed and can chroot into it, however, I can not get it to call for the keys on the USB during boot. I did find a how-to saying I needed to make a cryptroot conf for initramfs but, I believe that is for a passphrase: https://help.ubuntu.com/community/EncryptedFilesystemLVMHowto#Notes_for_making_it_work_in_Ubuntu_12.04_.22Precise_Pangolin.22_amd64 I also tried to setup crypttab. However, crypttab only works for drives mounted after the root drive as calling for a keyfile on a device not yet mounted to the system doesnt work. The Feisty how-to included scripts that would be run during boot instructing initramfs to mount the usb drive temporarily and call the keyfile for root which worked quite well except those scripts are outdated now, many of the things they relied on have been merged into something else, changed, or simply don't exist anymore. If I have missed a clear how-to for this, that would be wonderful, I just don't think I have.

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• Code Coverage for Maven Integrated in NetBeans IDE 7.2

  - by Geertjan

  In NetBeans IDE 7.2, JaCoCo is supported natively, i.e., out of the box, as a code coverage engine for Maven projects, since Cobertura does not work with JDK 7 language constructs. (Although, note that Cobertura is supported as well in NetBeans IDE 7.2.) It isn't part of NetBeans IDE 7.2 Beta, so don't even try there; you need some development build from after that. I downloaded the latest development build today. To enable JaCoCo features in NetBeans IDE, you need do no different to what you'd do when enabling JaCoCo in Maven itself, which is rather wonderful. In both cases, all you need to do is add this to the "plugins" section of your POM: <plugin> <groupId>org.jacoco</groupId> <artifactId>jacoco-maven-plugin</artifactId> <version>0.5.7.201204190339</version> <executions> <execution> <goals> <goal>prepare-agent</goal> </goals> </execution> <execution> <id>report</id> <phase>prepare-package</phase> <goals> <goal>report</goal> </goals> </execution> </executions> </plugin> Now you're done and ready to examine the code coverage of your tests, whether they are JUnit or TestNG. At this point, i.e., for no other reason than that you added the above snippet into your POM, you will have a new Code Coverage menu when you right-click on the project node: If you click Show Report above, the Code Coverage Report window opens. Here, once you've run your tests, you can actually see how many classes have been covered by your tests, which is pretty useful since 100% tests passing doesn't mean much when you've only tested one class, as you can see very graphically below: Then, when you click the bars in the Code Coverage Report window, the class under test is shown, with the methods for which tests exist highlighted in green and those that haven't been covered in red: (Note: Of course, striving for 100% code coverage is a bit nonsensical. For example, writing tests for your getters and setters may not be the most useful way to spend one's time. But being able to measure, and visualize, code coverage is certainly useful regardless of the percentage you're striving to achieve.) Best of all about all this is that everything you see above is available out of the box in NetBeans IDE 7.2. Take a look at what else NetBeans IDE 7.2 brings for the first time to the world of Maven: http://wiki.netbeans.org/NewAndNoteworthyNB72#Maven

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• GWT: Generate more complete crawl error report

  - by Mike

  I'm a developer in charge of managing Webmasters and related issues (including correcting crawl errors) for dozens (hundreds, maybe?) of active sites and as part of my duties I create a report of every discrepancy, including all pages generating a 404 and all pages that link to those pages. Currently within Webmaster Tools I'm able to download a csv file of all pages with a 404 response, but I'm then having to manually click on every single one of those links and copy the "linked from" field to paste into my spreadsheet. This is extremely tedious and seems unnecessary; I would expect the ability to download all that data at once. I'm ultimately looking for the end result of one csv file that has every url with a 404, but also has every url that links to each one of them. Am I overlooking this functionality somewhere or does anyone have a good solution? Edit 1 (2/11/2013): Example of what the csv output looks like now: URL,Response Code,News Error,Detected,Category http://www.abcdef.com/123.php,404,,11/12/13,Not found http://www.abcdef.com/456.php,404,,11/12/13,Not found Which is great, but let's say 123.php has 5 pages that link to it. Now I have to duplicate that row in my spreadsheet 4 more times, then go into Webmasters, get all the url's that link to the page, and add that data to my spreadsheet. The output I would prefer: URL,Response Code,Linked From,News Error,Detected,Category http://www.abcdef.com/123.php,404,http://www.ghijkl.com/naughtypage1.php,,11/12/13,Not found http://www.abcdef.com/123.php,404,http://www.ghijkl.com/naughtypage2.php,,11/12/13,Not found http://www.abcdef.com/123.php,404,http://www.ghijkl.com/naughtypage3.php,,11/12/13,Not found http://www.abcdef.com/456.php,404,http://www.ghijkl.com/naughtypage1.php,,11/12/13,Not found http://www.abcdef.com/456.php,404,http://www.ghijkl.com/naughtypage2.php,,11/12/13,Not found http://www.abcdef.com/456.php,404,http://www.ghijkl.com/naughtypage3.php,,11/12/13,Not found Note the (hypothetical) addition of a "Linked From" column, as well as the fact there are only 2 unique URL's now (like before) but all of the "Linked To" pages are shown in one report. Edit 2 (2/12/2013): To clarify, my question is less about detecting and correcting 404's, but more about generating a report of what Google has listed as errors. Oftentimes, these errors aren't even valid anymore but I still need documentation to show that Google detected a problem and that problem is now fixed. Many of the "linked from" url's I find are actually outdated, cached resources. For example, I'll frequently see that the linked-from url is the sitemap, which is actually an old sitemap cached by Google that points to an old page. Neither the sitemap or old page exist, but they still appear in my crawl error reports because they are cached resources.

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• HDMI sound gone, can't figure out how to turn it back on

  - by Oli

  I have had an Acer Revo box as a media centre for a while. I recently installed Ubuntu Server (10.10) on it and polished it up with nodm (one of the most simple ways to launch an X session) and installed boxee. It's been working fine for over a month. It's just running ALSA. I've had problems with PulseAudio/Boxee/HDMI before so I wanted to keep it simple. And that worked. It pushed both PCM and digital (AAC and various Dolby codecs) over HDMI perfectly. But I restarted it the other day after mucking around with some nfs configuration and now there isn't any sound. The hardware is an ION chipset. Nvidia 9400M graphics with Nvidia MCP79/7A audio. One thing I have noticed is there doesn't appear to be any sign of a IEC958 device. A traditional fix in the past for fresh installs has been to load alsamixer, find the IEC device and toggle its mute but I can't. I'm certain this used to represent the HDMI output. It just doesn't seem to exist any more unless I run sudo alsa-utils restart while boxee is running, when I see it in an error message: * Shutting down ALSA... [ OK ] * Setting up ALSA... * warning: 'alsactl restore' failed with error message 'alsactl: set_control:1388: Cannot write control '2:0:0:IEC958 Playback Default:0' : Operation not permitted'... ...done. When nodm (and thus boxee) aren't running, I don't see this error but alsamixer still doesn't show the IEC channel. aplay -l gives: card 0: NVidia [HDA NVidia], device 0: ALC662 rev1 Analog [ALC662 rev1 Analog] Subdevices: 1/1 Subdevice #0: subdevice #0 card 0: NVidia [HDA NVidia], device 3: HDMI 0 [HDMI 0] Subdevices: 0/1 Subdevice #0: subdevice #0 Its section in lshw reads: *-multimedia description: Audio device product: MCP79 High Definition Audio vendor: nVidia Corporation physical id: 8 bus info: pci@0000:00:08.0 version: b1 width: 32 bits clock: 66MHz capabilities: pm bus_master cap_list configuration: driver=HDA Intel latency=0 maxlatency=5 mingnt=2 resources: irq:22 memory:fae78000-fae7bfff I was running on the stock PAE kernel but now it's running on 2.6.37.1. I upgraded to see if that fixed things; it didn't. I'm considering a reinstall but I hate doing that because a) there's a bit of custom configuration in getting X and Boxee to start on boot and b) I don't know what the problem is. If I reinstall this time, I'll end up doing that every time the sound breaks. I love Ubuntu but I don't want to install it once a month. Is there any way to forcibly reset all alsa settings and restart from scratch (without doing a reinstall)? Any other tips? If you need more information, just ask.

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• What do you do when practical problems get in the way of practical goals?

  - by P.Brian.Mackey

  UPDATE Source control is good to use. Sometimes, real world issues make it impractical to use. For example: If the team is not used to using source control, training problems can arise If a team member directly modifies code on the server, various issues can arise. Merge problems, lack of history, etc Let's say there's a project that is way out of sync. The physical files on the server differ in unknown ways over ~100 files. Merging would take not only a great knowledge of the project, but is also well beyond the ability to complete in the given time. Other projects are falling out of sync. Developers continue to have a distrust of source control and therefore compound the issue by not using source control. Developers argue that using source control is wasteful because merging is error prone and difficult. This is a difficult point to argue, because when source control is being so badly mis-used and source control continually bypassed, it is error prone indeed. Therefore, the evidence "speaks for itself" in their view. Developers argue that directly modifying source control saves time. This is also difficult to argue. Because the merge required to synchronize the code to start with is time consuming, across ~10 projects. Permanent files are often stored in the same directory as the web project. So publishing (full publish) erases these files that are not in source control. This also drives distrust for source control. Because "publishing breaks the project". Fixing this (moving stored files out of the solution subfolders) takes a great deal of time and debugging as these locations are not set in web.config and often exist across multiple code points. So, the culture persists itself. Bad practice begets more bad practice. Bad solutions drive new hacks to "fix" much deeper, much more time consuming problems. Servers, hard drive space are extremly difficult to come by. Yet, user expectations are rising. What can be done in this situation?

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• No network connectivity (not wired or wireless) - RT5390

  - by Ben Udy

  I am starting to think I simply need to accept a small loss and sell my new ASUS K73E. Because I really don't enjoy computing when I have to deal with Windough$ and this windows 7 64 bit on my new ASUS is even worse than the old machines with XP. I have written to ASUS and they simply say "We don't support Linux" and while Ralink's website says they do support Linux I can't get anyone to tell me what model Ralink card might be in my machine. Is anyone out there who might be able to give me some useful advice???? Here is the answer to command lspci nn && lsusb && lsmod && rfkill list all: di,snd_seq snd 54244 16 snd_hda_codec_realtek,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_seq_oss,snd_rawmidi,snd_seq,snd_timer,snd_seq_device uvcvideo 57374 0 videodev 34361 1 uvcvideo v4l1_compat 13251 2 uvcvideo,videodev soundcore 6620 1 snd snd_page_alloc 7076 2 snd_hda_intel,snd_pcm psmouse 63677 0 serio_raw 3978 0 lp 7028 0 parport 32635 2 ppdev,lp fbcon 35102 71 tileblit 1999 1 fbcon font 7557 1 fbcon bitblit 4707 1 fbcon softcursor 1189 1 bitblit video 17375 0 output 1871 1 video vga16fb 11385 1 vgastate 8961 1 vga16fb ahci 32360 2 di,snd_seq snd 54244 16 snd_hda_codec_realtek,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_seq_oss,snd_rawmidi,snd_seq,snd_timer,snd_seq_device uvcvideo 57374 0 videodev 34361 1 uvcvideo v4l1_compat 13251 2 uvcvideo,videodev soundcore 6620 1 snd snd_page_alloc 7076 2 snd_hda_intel,snd_pcm psmouse 63677 0 serio_raw 3978 0 lp 7028 0 parport 32635 2 ppdev,lp fbcon 35102 71 tileblit 1999 1 fbcon font 7557 1 fbcon bitblit 4707 1 fbcon softcursor 1189 1 bitblit video 17375 0 output 1871 1 video vga16fb 11385 1 vgastate 8961 1 vga16fb ahci 32360 2 Edit #2 lspci 00:00.0 Host bridge: Intel Corporation Device 0104 (rev 09) 00:02.0 VGA compatible controller: Intel Corporation Device 0116 (rev 09) 00:16.0 Communication controller: Intel Corporation Cougar Point HECI Controller #1 (rev 04) 00:1a.0 USB Controller: Intel Corporation Cougar Point USB Enhanced Host Controller #2 (rev 05) 00:1b.0 Audio device: Intel Corporation Cougar Point High Definition Audio Controller (rev 05) 00:1c.0 PCI bridge: Intel Corporation Cougar Point PCI Express Root Port 1 (rev b5) 00:1c.1 PCI bridge: Intel Corporation Cougar Point PCI Express Root Port 2 (rev b5) 00:1c.5 PCI bridge: Intel Corporation Cougar Point PCI Express Root Port 6 (rev b5) 00:1d.0 USB Controller: Intel Corporation Cougar Point USB Enhanced Host Controller #1 (rev 05) 00:1f.0 ISA bridge: Intel Corporation Device 1c49 (rev 05) 00:1f.2 SATA controller: Intel Corporation Cougar Point 6 port SATA AHCI Controller (rev 05) 00:1f.3 SMBus: Intel Corporation Cougar Point SMBus Controller (rev 05) 02:00.0 Network controller: RaLink Device 5390 03:00.0 Ethernet controller: Atheros Communications Device 1083 (rev c0) lsusb Bus 002 Device 002: ID 8087:0024 Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 003: ID 13d3:5710 IMC Networks Bus 001 Device 002: ID 8087:0024 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Thanks for the suggestion because this gave me a model for Ralink RT5390. I have now gone to Ralink.com and downloaded (via Windows 7) the driver package (it is a bz2 file). I hope I can figure out how to install it. And FYI - I was not able to run su (not authorized?) and dmidecode didn't exist (probably needs to be downloaded BUT no internet yet in Ubuntu)

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• Simple collision detection in Unity 2D

  - by N1ghtshade3

  I realise other posts exist with this topic yet none have gone into enough detail for me. I am attempting to create a 2D game in Unity using C# as my scripting language. Basically I have two objects, player and bomb. Both were created simply by dragging the respective PNG to the stage. I have set up touch controls to move player left and right; gravity of any kind is not needed as I only require it to move x units when I tap either the left or right side of the screen. This movement is stored in a script called playerController.cs and works just fine. I also have a variable health = 3 for player, which is stored in healthScript.cs. I am now at a point where I am stuck. I would like it so that when player collides with bomb, health decreases by one and the bomb object is destroyed. So what I tried doing is using a new script called playerPhysics.cs, I added the following: void OnCollisionEnter2D(Collision2D coll){ if(coll.gameObject.name=="bomb") GameObject.Destroy("bomb"); healthScript.health -= 1; } While I'm fairly sure I don't know the proper way to reference a variable in another script and that's why the health didn't decrease when I collided, bomb never disappeared from the stage so I'm thinking there's also a problem with my collision. Initially, I had simply attached playerPhysics.cs to player. After searching around though, it appeared as though player also needed a rigidBody attached to it, so I did that. Still no luck. I tried using a circleCollider (player is a circle), using a rigidBody2D, and using all manner of colliders on one and/or both of the objects. If you could please explain what colliders (if any) should be attached to which objects and whether I need to change my script(s), that would be much more helpful than pointing me to one of the generic documentation examples I've already read. Also, if it would be simple to fix the health thing not working that would be an added bonus but not exactly the focus of this question. Bear in mind that this game is 2D; I'm not sure if that changes anything. Thanks!

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• Why should I not do a masters degree

  - by aurel

  I have left university on July 2010 where I studied web design (as we all know you learn more by your self but that’s not the issue at the moment). Since then I have not managed to find a job (apart from a one month work experience), from the way things are going, and by taking into account the fact that all my university friends are in the same situation, I don’t think that I am going to find a job soon (within the industry) Now as we all do, even though I don’t have a job, I am still working on personal projects and try to keep up to date (I don’t need a job or uni to do this) – but I am thinking, because there is not work available, would it be worth going back to uni for a master degree? I know I don’t need it and I know that is unlikely that I will learn anything important, as I believe in self learning, and in most cases it is a lot more effective (but I have to say I don’t mind going back to school) The only reason I am thinking of doing the master is, (and this is where I need your help): If it takes me a year to get a job, then on the interview, would the employer think “what the hell did this guy do since he left university” – now if I go to university that would solve this problem. Or I’m I making up a problem that does not exist Plus, I know that employers need examples of sites that I have been working on, at the moment I only have 3 (as when working on personal projects, where their is not time limit I tend drag things in order to get them perfect, and they never get perfect) – so by going back to uni, then this problem maybe solved I said all this as I have read a lot about the fact that you don’t need to have a masters degree to work on web design market (and I totally agree) but considering my concern, the question is should I do a masters course to avoid just spending hours in my room working and learning in my own (but that it would be hard to convince employers that I was really learning in my room) Maybe because I’m still young age 22 not that old anyway :), but I don’t have the “dream” of being rich, so if I were to tell the truth I don’t really care of the fact that I don’t have a job (at the moment), because regardless, I am working on what I love every day, but I know that in the future when I will need the job I may find it harder to get one, if I neglect doing so now Every time I ask a question that I’m not sure about, I keep going on and on, but I really hope you get what I am trying to get across. By the way the course that I am looking at for a masters says that it would teach me how to do these: e-commerce e-government e-science e-learning I don’t know any of them, a part from e-commerce Thanks

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• Editing /.config/dconf/user

  - by user86322

  I am having a problem with Gnome3 (actually, I have it set to fallback mode, or Gnome 2). I have two displays and I need an X screen (I used nvidia-xconfig and nvidia-settings to do this) for each screen. However, every time I either restart X or log in, Gnome seems to be adding the objects values under /gnome/gnome-panel/layouts (ex. first time I set the two separate X screens I had clock, then log out/in, there was clock and clock1 under objects, and then log out/in there were three, clock, clock1, clock2,.......log out/in, ............30 times....clock, clock1, clock2, ......clock 42.....!! The same thing goes for top-panels, menu-bars, etc.) After a while, I found out I could remove all those using the dconf-editor, going to /gnome/gnome-panel/layouts, removing all the repetitions under fields objects-id-list and top-id-list and leaving one value of each object. This is not a solution but at least allow me to keep using Linux without so much problem. However, the problem persists every time I restart X or log in. I now finally learned about "dconf" and where the user profile settings are located (~/.config/dconf/user) and one can use "dconf" to see the keys. In my case, I need to change/remove many keys (all those clocksX, workspace-X, menu-bar-X, etc., where goes from 1 to 42 and still counting) so it's really tedious and boring to be changing one by one using "dconf write". So I found "dconf dump", which actually allow me to dump everything into a .txt file and edit the file really quick (i.e, "dconf dump / >> dump_user.txt"). The problems? Two of them: How do I "load" back "dump_user.txt" I edited into the user profile? (I read somewhere there was a "dconf reload" but reload doesn't exist as a command under "dconf") How do I stop Gnome from keep adding more objects to my desktop environment every time I log in/restart X? NOTE: The problem doesn't occur when I set the displays to use TwinView feature (i.e., the desktop is extended/shared by both displays). However, for my case I need two separate X's. Any help/suggestion would be greatly appreciated. Thanks

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• How can I make a universal construction more efficient?

  - by VF1

  A "universal construction" is a wrapper class for a sequential object that enables it to be linearized (a strong consistency condition for concurrent objects). For instance, here's an adapted wait-free construction, in Java, from [1], which presumes the existence of a wait-free queue that satisfies the interface WFQ (which only requires one-time consensus between threads) and assumes a Sequential interface: public interface WFQ<T> // "FIFO" iteration { int enqueue(T t); // returns the sequence number of t Iterable<T> iterateUntil(int max); // iterates until sequence max } public interface Sequential { // Apply an invocation (method + arguments) // and get a response (return value + state) Response apply(Invocation i); } public interface Factory<T> { T generate(); } // generate new default object public interface Universal extends Sequential {} public class SlowUniversal implements Universal { Factory<? extends Sequential> generator; WFQ<Invocation> wfq = new WFQ<Invocation>(); Universal(Factory<? extends Sequential> g) { generator = g; } public Response apply(Invocation i) { int max = wfq.enqueue(i); Sequential s = generator.generate(); for(Invocation invoc : wfq.iterateUntil(max)) s.apply(invoc); return s.apply(i); } } This implementation isn't very satisfying, however, since it presumes determinism of a Sequential and is really slow. I attempted to add memory recycling: public interface WFQD<T> extends WFQ<T> { T dequeue(int n); } // dequeues only when n is the tail, else assists other threads public interface CopyableSequential extends Sequential { CopyableSequential copy(); } public class RecyclingUniversal implements Universal { WFQD<CopyableSequential> wfqd = new WFQD<CopyableSequential>(); Universal(CopyableSequential init) { wfqd.enqueue(init); } public Response apply(Invocation i) { int max = wfqd.enqueue(i); CopyableSequential cs = null; int ctr = max; for(CopyableSequential csq : wfq.iterateUntil(max)) if(--max == 0) cs = csq.copy(); wfqd.dequeue(max); return cs.apply(i); } } Here are my specific questions regarding the extension: Does my implementation create a linearizable multi-threaded version of a CopyableSequential? Is it possible extend memory recycling without extending the interface (perhaps my new methods trivialize the problem)? My implementation only reduces memory when a thread returns, so can this be strengthened? [1] provided an implementation for WFQ<T>, not WFQD<T> - one does exist, though, correct? [1] Herlihy and Shavit, The Art of Multiprocessor Programming.

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• What is a good strategy for binding view objects to model objects in C++?

  - by B.J.

  Imagine I have a rich data model that is represented by a hierarchy of objects. I also have a view hierarchy with views that can extract required data from model objects and display the data (and allow the user to manipulate the data). Actually, there could be multiple view hierarchies that can represent and manipulate the model (e.g. an overview-detail view and a direct manipulation view). My current approach for this is for the controller layer to store a reference to the underlying model object in the View object. The view object can then get the current data from the model for display, and can send the model object messages to update the data. View objects are effectively observers of the model objects and the model objects broadcast notifications when properties change. This approach allows all the views to update simultaneously when any view changes the model. Implemented carefully, this all works. However, it does require a lot of work to ensure that no view or model objects hold any stale references to model objects. The user can delete model objects or sub-hierarchies of the model at any time. Ensuring that all the view objects that hold references to the model objects that have been deleted is time-consuming and difficult. It feels like the approach I have been taking is not especially clean; while I don't want to have to have explicit code in the controller layer for mediating the communication between the views and the model, it seems like there must be a better (implicit) approach for establishing bindings between the view and the model and between related model objects. In particular, I am looking for an approach (in C++) that understands two key points: There is a many to one relationship between view and model objects If the underlying model object is destroyed, all the dependent view objects must be cleaned up so that no stale references exist While shared_ptr and weak_ptr can be used to manage the lifetimes of the underlying model objects and allows for weak references from the view to the model, they don't provide for notification of the destruction of the underlying object (they do in the sense that the use of a stale weak_ptr allows for notification), but I need an approach that notifies the dependent objects that their weak reference is going away. Can anyone suggest a good strategy to manage this?

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• How to handle this unfortunately non hypothetical situation with end-users?

  - by User Smith

  I work in a medium sized company but with a very small IT force. Last year (2011), I wrote an application that is very popular with a large group of end-users. We hit a deadline at the end of last year and some functionality (I will call funcA from now on) was not added into the application that was wanted at the very end. So, this application has been running in live/production since the end of 2011, I might add without issue. Yesterday, a whole group of end-users started complaining that funcA that was never in the application is no longer working. Our priority at this company is that if an application is broken it must be fixed first prior to prioritized projects. I have compared code and queries and there is no difference since 2011, which is proofA. I then was able to get one of the end-users to admit that it never worked proofB, but since then that end-user has went back and said that it was working previously......I believe the horde of end-users has assimilated her. I have also reviewed my notes for this project which has requirements and daily updates regarding the project which specifically states, "funcA not achieved due to time constraints", proofC. I have spoken with many of them and I can see where they could be confused as they are very far from a programming background, but I also know they are intelligent enough to act in a group in order to bypass project prioritization orders in order to get functionality that they want to make their job easier. The worst part is is that now group think is setting in and my boss and the head of IT is actually starting to believe them, even though there is no code or query changes. As far as reviewing the state of the logic it is very cut and dry to the point of if 1 = 1, funcA will not work. So, this is the end of the description of my scenario, but I am trying not to get severally dinged on my performance metrics due to this which would essentially have me moved to fixing a production problem that doesn't exist that will probably take over 1 month. I am looking for direct answers to this question. This question is not for rants, polling, or discussions as this is not the format for StackExchange. Please don't downvote me too terribly it is pretty common on this specific site of stack, I am looking for honest answers to this situation and I couldn't find a forum more appropriate.

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• Writing or extending existing emacs packages: is it worth or should I move to Netbeans/Eclipse?

  - by Andrea

  I'm finishing my master degree course in CS and I've almost become addicted to Emacs. I've used it to write in C, Latex, Java, JSP,XML, CommonLisp, Ada and other languages no other editor supported, like AMPL. I'd like to improve the packages I've been using the most or create new ones, but, in practice, I find that the implementation of Emacs leaves a lot to be desired. There are a lot of poorly-featured/poorly-maintained packages with either overlapping functionalities or obscure incompatibilities, and Elisp just seems to foster the situation by lacking the common features modern lisps have. In contrast Eclipse and Netbeans are actively improved and it does seem they can be effective for non-mainstream languages. I tried Hibachi for Ada in Eclipse and it worked well, there's CUPS for Lisp in Eclipse and LambdaBeans built using NetBeans components. On the other hand those plugins seem to be less active than their Emacs' counterparts, for example Hibachi was archived last year. What's your opinion on this? Which editor should I write extension for? EDIT: To answer Larry Coleman (see comment below): I like Emacs as a user because it is efficient both for me and the computer I'm using. It's fast and the textual interface (i.e. minibuffer) allows for quick interaction. It's solid and packages are usually small and easy to manage. If I need to correct or remove something I usually just have to change a row in my .emacs or an elisp file, or delete a directory. Eclipse plugins rely on a more complicated process that screwed my Eclipse configuration a couple of times, forcing me to do a clean reinstall. Emacs works as long as I use the basic packages. If I need something more complicated the situation gets pretty hairy. As a "power user" I think that the best I can hope for is to write a severely crippled version of the extensions I'd actually like to have; in other words, that it's not worth the trouble. I'd like to write extensions for the things I'd like to have automated in Emacs, for example project support with automated tag-table update on file writing. There are a few projects on this that lack integration, documentation, extensibility and so forth. The best one is probably CEDET, for which I believe the Greenspun's 10th rule can be applied. EDIT: To comment Larry Coleman's answer I'm pretty sure I can pick elisp programming but the extensions I have in mind don't exist yet despite their relative simplicity and the effort more knowledgeable people poured into related projects.This makes me wonder whether it is so because of the way emacs is developed, i.e. people tend to write their own little extensions without coordination, or its implementation, its extension language not being able to keep up with the growing complexity.

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• Is there an API for determining congressional districts?

  - by ardavis

  I'm looking to determine the congressional district based on an address my user is providing. This will avoid having the user to look it up themselves. Does an API of this sort exist? Note Through my attempts to find one, I've only come across these: http://www.govtrack.us/developers/api (not sure how to submit an an address or zip code however) The following resources are available in the API ...Bills and resolutions in the U.S. Congress since 1973 (the 93rd Congress). ...A (bill, person) pair indicating cosponsorship, with join and withdrawn dates. ...Members of Congress and U.S. Presidents since the founding of the nation. ...Terms held in office by Members of Congress and U.S. Presidents. Each term corresponds with an election, meaning each term in the House covers two years (one 'Congress'), as President four years, and in the Senate six years (three 'Congresses'). ...Roll call votes in the U.S. Congress since 1789. How people voted is accessed through the Vote_voter API. ...How people voted on roll call votes in the U.S. Congress since 1789. See the Vote API. Filter on the vote field to get the results of a particular vote... http://www.opencongress.org/api (seems to be a way to find congress information, but not districts) This API provides programmers with structured access to all the data on OpenCongress, everything from official bill info to news and blog coverage to user-generated votes on bills and much more... This API defaults to returning XML. All queries can also return JSON... https://groups.google.com/forum/?fromgroups=#!topic/opendems-discuss/CeKyi_aANaE (similar question, no resolution) I've been looking over Open Dems, and seeing what's exposed at this point and what isn't. I work with Democrats Abroad, and am interested in using stuff from the lab for their sites. I quickly looked over the Precinct API, which does both more and less than what I'd need. An ideal resource would be any way of translating addresses into CD at the very least (getting state district data would be good as well), since that would make it easier for DA's membership to make a difference in races like last month's NY26 race... Update I'm looking at the source for the govtrack.us website and the 'doGeoCode' function may be useful. view-source:http://www.govtrack.us/congress/members If no one has any suggestions, I will try to go off of what they are doing.

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• Failed to start up after upgrading software

  - by Landy

  I asked this question in SuperUser one hour ago, then I know this community so I moved the question here... I've been running Ubuntu 10.10 in a physical x86-64 machine. Today Update Manager reminded me that there are some updates to install and I confirmed the action. I should had read the update list but I didn't. I can only remember there is an update about cups. After the upgrading, Update Manager requires a restart and I confirmed too. But after the restart, the computer can't start up. There are errors in the console. Begin: Running /scripts/init-premount ... done. Begin: Mounting root file system ... Begin: Running /scripts/local-top ... done. [xxx]usb 1-8: new high speed USB device using ehci_hcd and address 3 [xxx]usb 2-1: new full speed USB device using ohci_hcd and address 2 [xxx]hub 2-1:1.0: USB hub found [xxx]hub 2-1:1.0: 4 ports detected [xxx]usb 2-1.1: new low speed USB device using ohci_hcd and address 3 Gave up waiting for root device. Common probles: - Boot args (cat /proc/cmdline) - Check rootdelay=(did the system wait long enough) - Check root= (did the system wait for the right device?) - Missing modules (cat /proc/modules; ls /dev) FATAL: Could not load /lib/modules/2.6.35-22-generic/modules.dep: No such file or directory FATAL: Could not load /lib/modules/2.6.35-22-generic/modules.dep: No such file or directory ALERT! /dev/sda1 does not exist. Dropping to a shell! BusyBox v1.15.3 (Ubuntu 1:1.15.3-1ubuntu5) built-in shell(ash) Enter 'help' for a list of built-in commands. (initramfs)[cursor is here] At the moment, I can't input anything in the console. The keyboard doesn't work at all. What's wrong? How can I check boot args or "root=" as suggested? How can I fix this issue? Thanks. =============== PS1: the /dev/sda1 is type ext4 (rw,nosuid,nodev) PS2: the /dev/sda1 can be mounted and accessed successfully under SUSE 11 SP1 x64. PS3: From this link, I think the keyboard doesn't work because the USB driver is not loaded at that time.

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• How do I maintain a really poorly written code base?

  - by onlineapplab.com

  Recently I got hired to work on existing web application because of NDA I'm not at liberty to disclose any details but this application is working online in sort of a beta testing stage before official launch. We have a few hundred users right now but this number is supposed to significantly increase after official launch. The application is written in PHP (but it is irrelevant to my question) and is running on a dual xeon processor standalone server with severe performance problems. I have seen a lot of bad PHP code but this really sets new standards, especially knowing how much time and money was invested in developing it. it is as badly coded as possible there is PHP, HTML, SQL mixed together and code is repeated whenever it is necessary (especially SQL queries). there are not any functions used, not mentioning any OOP there are four versions of the app (desktop, iPhone, Android + other mobile) each version has pretty much the same functionality but was created by copying the whole code base, so now there are some differences between each version and it is really hard to maintain the database is really badly designed, which is causing severe performance problems also for fixing some errors in PHP code there is a lot of database triggers used which are updating data on SELECT and on INSERT so any testing is a nightmare Basically, any sin of a bad programming you can imagine is there for example it is not only possible to use SQL injections in literally every place but you can log into app if you use a login which doesn't exist and an empty password. The team which created this app is not working on it any more and there is an outsourced team which suggested that there are some problems but was never willing to deal with the elephant in the room partially because they've got a very comfortable contract and partially due to lack of skills (just my opinion). My job was supposed to be fixing some performance problems and extending existing functionality but first thing I was asked to do was a review of the existing code base. I've made my review and it was quite a shock for the management but my conclusions were after some time finally confirmed by other programmers. Management made it clear that it is not possible to start rewriting this app from scratch (which in my opinion should be done). We have to maintain its operable state and at the same time fix performance errors and extend the functionality. My question is, as I don't want just to patch the existing code, how to transform this into properly written app while keeping the existing code working at the same time? My plan is: Unify four existing versions into common code base (fixing only most obvious errors). Redesign db and use triggers to populate it with data (so data will be maintained in two formats at the same time) All new functionality will be written as separate project. Step by step transfer existing functionality into the new project After some time everything will be in the new project Some explanation about #2, right now it is practically impossible to make any updates in existing db any change requires reviewing whole code and making changes in many places. Is such plan feasible at all? Another solution is to walk away and leave the headache to someone else.

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• Traditional POS is Dead

  - by David Dorf

  Traditional POS is dead -- I've heard that one before. Here's an excerpt from Joe Skorupa's blog over at RIS where he relayed ten trends that were presented at NRF. 7. Mobile POS signals death of traditional POS. Shoppers don't love self-checkout, but they prefer it to long queues or dealing with associates. Fixed POS is expensive and bulky. Mobile POS frees floor space for other purposes and converts associates from being cashiers to being sales assistants that provide new levels of customer service and incremental basket sales. In addition to unplugging the POS, new alternatives are starting to take hold - thin client, POS as a service, and replacing POS software with e-commerce platforms. I'll grant that in some situations for some retailers there might be an opportunity to to ditch the traditional POS, but for the majority of retailers that's just not practical. Take it from a guy that had to wake up at 3am after every Thanksgiving to monitor POS systems across the US on Black Friday. If a retailer's website goes down on Black Friday, they will take a significant hit. If a retailer's chain-wide POS system goes down on Black Friday, that retailer will cease to exist. Mobile POS works great for Apple because the majority of purchases are one or two big-ticket items that don't involve cash. There's still a traditional POS in every store to fall back on (its just hidden). Try this at home: Choose your favorite e-commerce site and add an item to the cart while timing how long it takes. Now multiply that by 15 to represent the 15 items you might buy at store like Target. The user interface isn't optimized for bulk purchases, and that's how it should be. The webstore and POS are designed for different purposes. Self-checkout is a great addition to POS and so is mobile checkout. But they add capabilities to POS, not replace it. Centralized architectures, even those based in the cloud, are quite viable as long as there's resiliency in the registers. You cannot assume perfect access to the network, so a POS must always be able to sell regardless of connectivity. Clearly the different selling channels should be sharing common functionality. Things like calculating tax, accepting coupons, and processing electronic payments can be shared, usually through a service-oriented architecture. This lowers costs and providers greater consistency, both of which help retailers. On paper these technologies look really good and we should continue to push boundaries, but I'm not ready to call the patient dead just yet.

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• So, I though I wanted to learn frontend/web development and break out of my comfort zone...

  - by ripper234

  I've been a backend developer for a long time, and I really swim in that field. C++/C#/Java, databases, NoSql, caching - I feel very much at ease around these platforms/concepts. In the past few years, I started to taste end-to-end web programming, and recently I decided to take a job offer in a front end team developing a large, complex product. I wanted to break out of my comfort zone and become more of an "all around developer". Problem is, I'm getting more and more convinced I don't like it. Things I like about backend programming, and missing in frontend stuff: More interesting problems - When I compare designing a server that handle massive data, to adding another form to a page or changing the validation logic, I find the former a lot more interesting. Refactoring refactoring refactoring - I am addicted to Visual Studio with Resharper, or IntelliJ. I feel very comfortable writing code as it goes without investing too much thought, because I know that with a few clicks I can refactor it into beautiful code. To my knowledge, this doesn't exist at all in javascript. Intellisense and navigation - I hate looking at a bunch of JS code without instantly being able to know what it does. In VS/IntelliJ I can summon the documentation, navigate to the code, climb up inheritance hiererchies ... life is sweet. Auto-completion - Just hit Ctrl-Space on an object to see what you can do with it. Easier to test - With almost any backend feature, I can use TDD to capture the requirements, see a bunch of failing tests, then implement, knowing that if the tests pass I did my job well. With frontend, while tests can help a bit, I find that most of the testing is still manual - fire up that browser and verify the site didn't break. I miss that feeling of "A green CI means everything is well with the world." Now, I've only seriously practiced frontend development for about two months now, so this might seem premature ... but I'm getting a nagging feeling that I should abandon this quest and return to my comfort zone, because, well, it's so comfy and fun. Another point worth mentioning in this context is that while I am learning some frontend tools, a lot of what I'm learning is our company's specific infrastructure, which I'm not sure will be very useful later on in my career. Any suggestions or tips? Do you think I should give frontend programming "a proper chance" of at least six to twelve months before calling it quits? Could all my pains be growing pains, and will they magically disappear as I get more experienced? Or is gaining this perspective is valuable enough, even if plan to do more "backend stuff" later on, that it's worth grinding my teeth and continuing with my learning?

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• Software engineering project idea feedback [on hold]

  - by Chris Sewell

  I'm a third year student currently undergoing my project/dissertation section of my degree. I have drafted a proposal for my final year project and would appreciate any feedback. The feedback can be anything constructive either specific to this proposal, the area that I will be working and researching in or my ideas. I will accept all input. Aims My aim is to attempt a proof of concept and prototype a runtime-as-a-service (RaaS). This cloud based runtime will allow clients to dynamically offload tasks or create cloud applications. Currently software-as-a-service (SaaS) cloud applications are purpose built and have a predefined scope in which they can assist or serve the client; this scope cannot be changed without physical alteration to the client and server software. With RaaS the client potentially could define any task it wanted at any time depending on its environment variables, the client and server would then communicate parameters and returns for that task. For the client to utilize a RaaS it must be able to conceive and then define a task using an appropriate XML vocabulary. As the scope of the cloud solution is defined by the client at its runtime, the cloud solution only has to exist for as long as the client requires it to as opposed to a client using a dedicated service. Deliverables The crux of the project will require an XML vocabulary in which the client and server will communicate. I’ll prototype the server application that will dynamically create and manage cloud solutions. The solution will be coded using an interpreted language, such as python or javascript, which can evaluate expressions in runtime or a language that can dynamically compile such as C# or Java. As a further proof of concept I will also produce a mock client that offloads tasks to the server. The report will attempt to explain the different flavours of cloud computing solutions including infrastructure-as-a-service (IaaS), platform-as-a-service (PaaS) and SaaS including real world examples and where the use of a RaaS could have improved the overall example solution. Disclaimer: I'm not requesting stakeholders in my project nor am I delegating work. Any materials other than feedback, advice or directions will not be utilized.

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• Welcome to ubiquitous file sharing (December 08, 2009)

  - by user12612012

  The core of any file server is its file system and ZFS provides the foundation on which we have built our ubiquitous file sharing and single access control model.  ZFS has a rich, Windows and NFSv4 compatible, ACL implementation (ZFS only uses ACLs), it understands both UNIX IDs and Windows SIDs and it is integrated with the identity mapping service; it knows when a UNIX/NIS user and a Windows user are equivalent, and similarly for groups.  We have a single access control architecture, regardless of whether you are accessing the system via NFS or SMB/CIFS.The NFS and SMB protocol services are also integrated with the identity mapping service and shares are not restricted to UNIX permissions or Windows permissions.  All access control is performed by ZFS, the system can always share file systems simultaneously over both protocols and our model is native access to any share from either protocol.Modal architectures have unnecessary restrictions, confusing rules, administrative overhead and weird deployments to try to make them work; they exist as a compromise not because they offer a benefit.  Having some shares that only support UNIX permissions, others that only support ACLs and some that support both in a quirky way really doesn't seem like the sort of thing you'd want in a multi-protocol file server.  Perhaps because the server has been built on a file system that was designed for UNIX permissions, possibly with ACL support bolted on as an add-on afterthought, or because the protocol services are not truly integrated with the operating system, it may not be capable of supporting a single integrated model.With a single, integrated sharing and access control model: If you connect from Windows or another SMB/CIFS client: The system creates a credential containing both your Windows identity and your UNIX/NIS identity.  The credential includes UNIX/NIS IDs and SIDs, and UNIX/NIS groups and Windows groups. If your Windows identity is mapped to an ephemeral ID, files created by you will be owned by your Windows identity (ZFS understands both UNIX IDs and Windows SIDs). If your Windows identity is mapped to a real UNIX/NIS UID, files created by you will be owned by your UNIX/NIS identity. If you access a file that you previously created from UNIX, the system will map your UNIX identity to your Windows identity and recognize that you are the owner.  Identity mapping also supports access checking if you are being assessed for access via the ACL. If you connect via NFS (typically from a UNIX client): The system creates a credential containing your UNIX/NIS identity (including groups). Files you create will be owned by your UNIX/NIS identity. If you access a file that you previously created from Windows and the file is owned by your UID, no mapping is required. Otherwise the system will map your Windows identity to your UNIX/NIS identity and recognize that you are the owner.  Again, mapping is fully supported during ACL processing. The NFS, SMB/CIFS and ZFS services all work cooperatively to ensure that your UNIX identity and your Windows identity are equivalent when you access the system.  This, along with the single ACL-based access control implementation, results in a system that provides that elusive ubiquitous file sharing experience.

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• C++ and SDL resource management for 2D game

  - by KuruptedMagi

  My first question is about stateManagers. I do not use the singleton pattern (read many random posts with various reasons not to use it), I have gameStateManager which runs the pointer cCurrentGameState-render(), etc. I want to make a transitioning game, this engine should ideally cover both a platformer and a bird's eye RPG (with some recoding, I just mean the base engine), both of which will load different levels and events, such as world map, dungeon, shops, etc. So I then thought, rather then having to store all this data within all the states, I would break the engine into gameStates, and playStates... when gameState reaches gameStatePlay(), gameStatePlay simply runs the usual handleInput, logic, and render for the playStates, just as the low level gameStateManager does. This lets me store all the player data within the base playstate class without storing useless data in the gameStates. Now I have added a seperate mapEditor, which uses editorStates from gameStateEditor. Is this too much usage of the gameState concept? It seems to work pretty well for me, so I was wondering if I am too far off a common implementation of this. My second question is on image resources. I have my sprite class with nothing but static members, mainly loadImage, applySurface, and my screen pointer. I also have a map pairing imageName enums with actual SDL_Surface pointers, and one pairing clipNumber enums with a wrapper class for a vector of clips, so that each reference in the map can have different amounts of clips with different sizes. I thought it would be better to store all these images, and screen within one static body, since 20 different goblins all use the same sprite sheet, and all need to print to the same screen, and of course, this way I do not need to pass my screen reference to every little entity. The imageMap seems to work very well, I can even add the ability to search through the map at creation of entity type to see if a particular image at creation, creating if it doesnt exist, and destroying the image if the last entity that needs it was just destroyed. The vectored clip map however, seems to take too long to initialize, so if i run past the state that initializes them to fast, the game crashes <. Plus, the clip map call is half of this line =P SPRITE::applySurface( cEditorMap.cTiles[x][y].iX, cEditorMap.cTiles[x][y].iY, SPRITE::mImages[ IMAGE_TILEMAP ], SPRITE::screen, SPRITE::mImageClips[IMAGE_TILEMAP]->clips.at( cEditorMap.cTiles[x][y].iTileType ) ); Again, do I have the right idea? I like the imageMap, but am I better off with each entity storing its own clips? My last question is about collision detection. I only grasp the basics, will look at per-pixel and circular soon, but how can I determine which side the collision comes from with just the basic square collision detection, I tried breaking each entity into 4 collision zones, but that just gave me problems with walking through walls and the like <. Also, is per-pixel color collision a good way to decide what collision just occured, or is checking multiple colors for multiple entities too taxing each cycle?

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• Failed to start up after upgrading software in ubuntu 10.10

  - by Landy

  I asked this question in SuperUser one hour ago, then I know this community so I moved the question here... I've been running Ubuntu 10.10 in a physical x86-64 machine. Today Update Manager reminded me that there are some updates to install and I confirmed the action. I should had read the update list but I didn't. I can only remember there is an update about cups. After the upgrading, Update Manager requires a restart and I confirmed too. But after the restart, the computer can't start up. There are errors in the console. Begin: Running /scripts/init-premount ... done. Begin: Mounting root file system ... Begin: Running /scripts/local-top ... done. [xxx]usb 1-8: new high speed USB device using ehci_hcd and address 3 [xxx]usb 2-1: new full speed USB device using ohci_hcd and address 2 [xxx]hub 2-1:1.0: USB hub found [xxx]hub 2-1:1.0: 4 ports detected [xxx]usb 2-1.1: new low speed USB device using ohci_hcd and address 3 Gave up waiting for root device. Common probles: - Boot args (cat /proc/cmdline) - Check rootdelay=(did the system wait long enough) - Check root= (did the system wait for the right device?) - Missing modules (cat /proc/modules; ls /dev) FATAL: Could not load /lib/modules/2.6.35-22-generic/modules.dep: No such file or directory FATAL: Could not load /lib/modules/2.6.35-22-generic/modules.dep: No such file or directory ALERT! /dev/sda1 does not exist. Dropping to a shell! BusyBox v1.15.3 (Ubuntu 1:1.15.3-1ubuntu5) built-in shell(ash) Enter 'help' for a list of built-in commands. (initramfs)[cursor is here] At the moment, I can't input anything in the console. The keyboard doesn't work at all. What's wrong? How can I check boot args or "root=" as suggested? How can I fix this issue? Thanks. =============== PS1: the /dev/sda1 is type ext4 (rw,nosuid,nodev) PS2: the /dev/sda1 can be mounted and accessed successfully under SUSE 11 SP1 x64. PS3: From this link, I think the keyboard doesn't work because the USB driver is not loaded at that time.

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• Switch from back-end to front-end programming: I'm out of my comfort zone, should I switch back?

  - by ripper234

  I've been a backend developer for a long time, and I really swim in that field. C++/C#/Java, databases, NoSql, caching - I feel very much at ease around these platforms/concepts. In the past few years, I started to taste end-to-end web programming, and recently I decided to take a job offer in a front end team developing a large, complex product. I wanted to break out of my comfort zone and become more of an "all around developer". Problem is, I'm getting more and more convinced I don't like it. Things I like about backend programming, and missing in frontend stuff: More interesting problems - When I compare designing a server that handle massive data, to adding another form to a page or changing the validation logic, I find the former a lot more interesting. Refactoring refactoring refactoring - I am addicted to Visual Studio with Resharper, or IntelliJ. I feel very comfortable writing code as it goes without investing too much thought, because I know that with a few clicks I can refactor it into beautiful code. To my knowledge, this doesn't exist at all in javascript. Intellisense and navigation - I hate looking at a bunch of JS code without instantly being able to know what it does. In VS/IntelliJ I can summon the documentation, navigate to the code, climb up inheritance hiererchies ... life is sweet. Auto-completion - Just hit Ctrl-Space on an object to see what you can do with it. Easier to test - With almost any backend feature, I can use TDD to capture the requirements, see a bunch of failing tests, then implement, knowing that if the tests pass I did my job well. With frontend, while tests can help a bit, I find that most of the testing is still manual - fire up that browser and verify the site didn't break. I miss that feeling of "A green CI means everything is well with the world." Now, I've only seriously practiced frontend development for about two months now, so this might seem premature ... but I'm getting a nagging feeling that I should abandon this quest and return to my comfort zone, because, well, it's so comfy and fun. Another point worth mentioning in this context is that while I am learning some frontend tools, a lot of what I'm learning is our company's specific infrastructure, which I'm not sure will be very useful later on in my career. Any suggestions or tips? Do you think I should give frontend programming "a proper chance" of at least six to twelve months before calling it quits? Could all my pains be growing pains, and will they magically disappear as I get more experienced? Or is gaining this perspective is valuable enough, even if plan to do more "backend stuff" later on, that it's worth grinding my teeth and continuing with my learning?

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