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  • Best way to update UI when dealing with data synchronization

    - by developerdoug
    I'm working on a bug at work. The app is written in Objective-C for iOS based device, for the iPad. I'm the new guy there and I've been given a hard task. Sometimes, the UIButton text property does not show the correct state when syncing. Basically, when the app is syncing, my UI control would say "Syncing" and when its not syncing it'll display "Updated @ [specific date]". Right now there is a property on the app delegate called "SyncInProgress". When querying / syncing, occurring on background thread, it updates a counter. The property will return a bool checking expression 'counter 0'. There are three states I need to deal with. Sync has started. Sync is updating tables. Sync finished. These items need to occur in order. My coworker suggested to take a state based approach instead of just responding to events. I'm not sure about how to go about that. Would it be best to have the UI receive a notification to determine what state its in or to pull every so often if state changed? Here are two posts that I put on stackoverflow, in the last few days, that relate to this. http://stackoverflow.com/questions/11025469/ios-syncing-using-a-state-approach-instead-of-just-reacting-to-events http://stackoverflow.com/questions/11037930/viewcontroller-when-viewwillappear-called-does-not-always-correctly-reflect-stat Any ideas that anyone might have to very much appreciated. Thanks, developerDoug

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  • X11 forwarding from one server to other

    - by n3oblit7
    I have a setup where I need to forward X11 from my local machine (laptop) to a Virtual machine. The server hosting this VM cannot be reached directly from my laptop. I need to first login to a gateway and from this gateway, I can access the VM. How can I forward X11 from my laptop to this VM? I have tried following but these do not work: [laptop # ] ssh -X [gateway] [gateway # ] ssh -X [VM] [laptop # ] ssh -tX [gateway] ssh -X [VM] I could forward X11 only till the gateway. (DISPLAY variable gets set on gateway)

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  • DVI-D Splitter Not Working with GeForce 8400gs

    - by jimdrang
    I have a GeForce 8400gs and it has a DVI and VGA port on the back. I was using dual monitors with one VGA and one DVI cable. I wanted both displays to be digital so I bought a DVI-D splitter and put one DVI cable in each monitor, connected them to the splitter and put the single merged connection in the back of the cards DVI connection. It will not recognize the second monitor (I'm not even sure how it determined which one was the first monitor). The tech specs state that it supports "Two dual-link DVI outputs for digital flat panel display resolutions up to 2560x1600" http://www.nvidia.com/object/geforce_8400_tech_specs.html. Do I need a different converter or is my only option for dual monitors with this card one VGA, one DVI?

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  • Migrating R Scripts from Development to Production

    - by Mark Hornick
    Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 “How do I move my R scripts stored in one database instance to another? I have my development/test system and want to migrate to production.” Users of Oracle R Enterprise Embedded R Execution will often store their R scripts in the R Script Repository in Oracle Database, especially when using the ORE SQL API. From previous blog posts, you may recall that Embedded R Execution enables running R scripts managed by Oracle Database using both R and SQL interfaces. In ORE 1.3.1., the SQL API requires scripts to be stored in the database and referenced by name in SQL queries. The SQL API enables seamless integration with database-based applications and ease of production deployment. Loading R scripts in the repository Before talking about migration, we’ll first introduce how users store R scripts in Oracle Database. Users can add R scripts to the repository in R using the function ore.scriptCreate, or SQL using the function sys.rqScriptCreate. For the sample R script     id <- 1:10     plot(1:100,rnorm(100),pch=21,bg="red",cex =2)     data.frame(id=id, val=id / 100) users wrap this in a function and store it in the R Script Repository with a name. In R, this looks like ore.scriptCreate("RandomRedDots", function () { line-height: 115%; font-family: "Courier New";">     id <- 1:10     plot(1:100,rnorm(100),pch=21,bg="red",cex =2)     data.frame(id=id, val=id / 100)) }) In SQL, this looks like begin sys.rqScriptCreate('RandomRedDots',  'function(){     id <- 1:10     plot(1:100,rnorm(100),pch=21,bg="red",cex =2)     data.frame(id=id, val=id / 100)   }'); end; / The R function ore.scriptDrop and SQL function sys.rqScriptDrop can be used to drop these scripts as well. Note that the system will give an error if the script name already exists. Accessing R scripts once they’ve been loaded If you’re not using a source code control system, it is possible that your R scripts can be misplaced or files modified, making what is stored in Oracle Database to only or best copy of your R code. If you’ve loaded your R scripts to the database, it is straightforward to access these scripts from the database table SYS.RQ_SCRIPTS. For example, select * from sys.rq_scripts where name='myScriptName'; From R, scripts in the repository can be loaded into the R client engine using a function similar to the following: ore.scriptLoad <- function(name) { query <- paste("select script from sys.rq_scripts where name='",name,"'",sep="") str.f <- OREbase:::.ore.dbGetQuery(query) assign(name,eval(parse(text = str.f)),pos=1) } ore.scriptLoad("myFunctionName") This function is also useful if you want to load an existing R script from the repository into another R script in the repository – think modular coding style. Just include this function in the body of the other function and load the named script. Migrating R scripts from one database instance to another To move a set of functions from one system to another, the following script loads the functions from one R script repository into the client R engine, then connects to the target database and creates the scripts there with the same names. scriptNames <- OREbase:::.ore.dbGetQuery("select name from sys.rq_scripts where name not like 'RQG$%' and name not like 'RQ$%'")$NAME for(s in scriptNames) { cat(s,"\n") ore.scriptLoad(s) } ore.disconnect() ore.connect("rquser","orcl","localhost","rquser") for(s in scriptNames) { cat(s,"\n") ore.scriptDrop(s) ore.scriptCreate(s,get(s)) } Best Practice When naming R scripts, keep in mind that the name can be up to 128 characters. As such, consider organizing scripts in a directory structure manner. For example, if an organization has multiple groups or applications sharing the same database and there are multiple components, use “/” to facilitate the function organization: line-height: 115%;">ore.scriptCreate("/org1/app1/component1/myFuntion1", myFunction1) ore.scriptCreate("/org1/app1/component1/myFuntion2", myFunction2) ore.scriptCreate("/org1/app2/component2/myFuntion2", myFunction2) ore.scriptCreate("/org2/app2/component1/myFuntion3", myFunction3) ore.scriptCreate("/org3/app2/component1/myFuntion4", myFunction4) Users can then query for all functions using the path prefix when looking up functions. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

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  • Make the Windows 8 Mail app sync and notify Gmail labels

    - by Matsemann
    My Windows 8 Mail app is connected with Gmail, and is set to sync emails and download emails on arrival. Most of my mail isn't going to the inbox, but is going straight to different labels. Say, all work related mail is going straight to the label Work. The problem is that when I have unread email in Work, the Mail app will not tell me. It will only display a label, Work, I can click on, not Work (1) indicating unread mails. When clicking the label, I will need to wait for some time for it to actually download and sync the mail before anything shows. Even if I tried force syncing just before. So: The Mail app is not syncing my labels, and will not give any visuals that a label contains unread mail. Is there any way to achieve this? Without it, the Mail app is unfortunately pretty useless to me.

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  • Creating Ubuntu Browser App Frames

    - by user73006
    After watching the video i am inspired to create one browser but stuck at one place, could you please help me with this. Requirement = - Like you displayed in your Video i wan create Multiple Buttons in my Toolbar which will open Second ToolBar or Popup Window. - From that Pop Window i wanted to Select Specific Button Which will open My Required Browser. Question - - As displayed in your Video i create new BUtton and If i try to open new link using that it works but now i want to display tool bar or Popup window once any one click on that button, how can i do that.The Second Tool Bar Need to be Activated only after clicking on that button. Things i Tried - - As per my understanding i create Second Toolbar and on that tool bar i have created Button, now i wan know how do i link that tool bar with my Browser Toolbar button. - I tried that by passing Signal Property in Second Toolbar in Quickly but something is missing. MY Code class TvbrowserWindow(Window): gtype_name = "TvbrowserWindow" def finish_initializing(self, builder): # pylint: disable=E1002 """Set up the main window""" super(TvbrowserWindow, self).finish_initializing(builder) self.AboutDialog = AboutTvbrowserDialog self.PreferencesDialog = PreferencesTvbrowserDialog # Code for other initialization actions should be added here. self.refreshbutton=self.builder.get_object("refreshbutton") self.SONY=self.builder.get_object("SONY") self.urlentry=self.builder.get_object("urlentry") self.scrolledwindow1=self.builder.get_object("scrolledwindow1") self.webview = WebKit.WebView() self.scrolledwindow1.add(self.webview) self.webview.show() def on_refreshbutton_clicked(self, widget): print "refresh" def on_urlentry_activate(self, widget): url = widget.get_text() print url self.webview.open(url)

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  • What is this video format, and how do I convert It

    - by OrangeRind
    Description I have a big (7.4G) .mkv file (1080p) which I want to convert to H.264 (using x264) Problem MediaCoder and GSpot are unable to detect the codec. They don't display anything. Just that the file is a matroska Container Video with a MIMEtype of video/x-matroska. No bitrate, profile etc. But the source tells me that is VC-1 encoded. Question So how do I encode this file. as in, using what encoding software, since MediaCoder has failed.

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  • seamless mode remote desktop connection from linux to windows

    - by mateusz.fiolka
    I am a programmer using Linux as my main OS, however sometimes I need to use windows (ie, office, ea). I'm running qemu with kvm to access the windows "machine". I would like to achieve something that is described here: https://help.ubuntu.com/community/SeamlessVirtualization (It means I would be able to run chosen applications on Windows and then display them locally on Linux as separate windows achieving good desktop integration). However seamless rdp is buggy and doesn't work on my machine (probably because I'm using a tiling window manager and a 64bit system). Are you aware of any other solution then rdp seamless mode? I would prefer to still use quemu because it uses cpu hardware virtualization, so different protocol/client combination would be preferable.

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  • How do I stop color changes when quitting vi from a terminal emulator?

    - by Michael Warhol
    I have a problem with colors when using vi under Ubuntu 12.04. I'm connecting to my Ubuntu server from a PC, using PowerTerm terminal emulation software. I have PowerTerm set up to display black text on a grey background. When I connect to the Ubuntu box, the screen is fine. When I open a file with vi, the screen is fine. The text is black on a gray background, which is normal for my PowerTerm setup. However, if the file is less than a full screen long, the remainder of the screen is a black background. When I quit vi, the entire background turns black, and the text becomes white. I have to do a Terminal Reset to restore my normal text and background colors. What I want is for there to be no change at all when I use vi. The text should be black and the background grey. I have another server loaded with RedHat 9, and that acts normally; colors don’t change when using vi. Here is my .vimrc file: set compatible syntax off let g:loaded_matchparen=1 set nocp set noincsearch set nohlsearch set noshowmatch set bg=dark I've tried set bg=dark and set bg=light. It makes no difference. Is there some other set command that would clear this up for me, or some TERM setting (my TERM is set to linux)?

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  • Debugger for file I/O development?

    - by datenwolf
    Okay, the question title may be a bit cryptic. But it aptly describes what I'm looking for: I think every experienced coder went through this numerous times: You get a binary file format specification, you implement the reader for it, and… nothing works like expected. So you run your code in the debugger, go execute through the code line by line, every header field is read in seemingly correct, but when it comes to the bulk data, offset and indices no longer match up. What would really help in this situation was a binary file viewer, that shows you the progress of your file pointer, as you step through the code, and ideally would also highlight all memory maps. Then you could see the context of the current I/O operations, most notably those darn "off-by-one" mistakes, which are even more annoying when reading a file. Implementing such a debugger should not be too hard. traces on the process' file descriptors/handles and triggers on the I/O functions, to update the display. Only: I don't know of such a kind of debugger to exist. Do I just lack knowledge about the existance of such a tool, or is there really no such thing?

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  • Check if current Command Prompt was launched as the Administrator

    - by Canadian Luke
    I am looking to write a script that takes user input, then makes system wide changes. I need this to be very generic, but simply put, at the top, I need it to check to see if it's being run 'As an Administrator'. If it's not, then I want to display a message to tell them that; if it is, I want it to continue on. Is there a constant way to verify this? I am not looking to start a new session as the Administrator, I just want to detect if it's currently run as admin

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  • ISP issue browsing "sonos.com" - need to diagnose and prove [closed]

    - by john
    I am unable to browse to a website "sonos.com" with my ISP (virgin). I have ruled out browsers, PCs, macs, routers, wifi, etc. Other ISPs (even other virgin connections in different areas!) supply this site no problem. I am 99% convinced there is a DNS issue lurking here. There is something fishy about the DNS for the site : What I notice is that online DNS sites tell me the right IP address for "sonos.com", but not for "www.sonos.com". Anyway when I type "sonos.com" the browser (any/all of the 4 I tried) fail to display the page. Firefox gives a "connection was reset" error. If I browse to sonos.com using the IP address it works OK. Browsing to www.sonos.com or sonos.com works fine with other ISPs of course. Questions: 1 Does anyone have any idea what might be going on here? 2 Any suggestions as to tools/monitors to help investigate/prove what is going on I can then take this up with virgin and/or sonos. Thanks

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  • Concurrency Utilities for Java EE Early Draft (JSR 236)

    - by arungupta
    Concurrency Utilities for Java EE is being worked as JSR 236 and has released an Early Draft. It provides concurrency capabilities to Java EE application components without compromising container integrity. Simple (common) and advanced concurrency patterns are easily supported without sacrificing usability. Using Java SE concurrency utilities such as java.util.concurrent API, java.lang.Thread and java.util.Timer in a Java EE application component such as EJB or Servlet are problematic since the container and server have no knowledge of these resources. JSR 236 enables concurrency largely by extending the Concurrency Utilities API developed under JSR-166. This also allows a consistency between Java SE and Java EE concurrency programming model. There are four main programming interfaces available: ManagedExecutorService ManagedScheduledExecutorService ContextService ManagedThreadFactory ManagedExecutorService is a managed version of java.util.concurrent.ExecutorService. The implementations of this interface are provided by the container and accessible using JNDI reference: <resource-env-ref>  <resource-env-ref-name>    concurrent/BatchExecutor  </resource-env-ref-name>  <resource-env-ref-type>    javax.enterprise.concurrent.ManagedExecutorService  </resource-env-ref-type><resource-env-ref> and available as: @Resource(name="concurrent/BatchExecutor")ManagedExecutorService executor; Its recommended to bind the JNDI references in the java:comp/env/concurrent subcontext. The asynchronous tasks that need to be executed need to implement java.lang.Runnable or java.util.concurrent.Callable interface as: public class MyTask implements Runnable { public void run() { // business logic goes here }} OR public class MyTask2 implements Callable<Date> {  public Date call() { // business logic goes here   }} The task is then submitted to the executor using one of the submit method that return a Future instance. The Future represents the result of the task and can also be used to check if the task is complete or wait for its completion. Future<String> future = executor.submit(new MyTask(), String.class);. . .String result = future.get(); Another example to submit tasks is: class MyTask implements Callback<Long> { . . . }class MyTask2 implements Callback<Date> { . . . }ArrayList<Callable> tasks = new ArrayList<();tasks.add(new MyTask());tasks.add(new MyTask2());List<Future<Object>> result = executor.invokeAll(tasks); The ManagedExecutorService may be configured for different properties such as: Hung Task Threshold: Time in milliseconds that a task can execute before it is considered hung Pool Info Core Size: Number of threads to keep alive Maximum Size: Maximum number of threads allowed in the pool Keep Alive: Time to allow threads to remain idle when # of threads > Core Size Work Queue Capacity: # of tasks that can be stored in inbound buffer Thread Use: Application intend to run short vs long-running tasks, accordingly pooled or daemon threads are picked ManagedScheduledExecutorService adds delay and periodic task running capabilities to ManagedExecutorService. The implementations of this interface are provided by the container and accessible using JNDI reference: <resource-env-ref>  <resource-env-ref-name>    concurrent/BatchExecutor  </resource-env-ref-name>  <resource-env-ref-type>    javax.enterprise.concurrent.ManagedExecutorService  </resource-env-ref-type><resource-env-ref> and available as: @Resource(name="concurrent/timedExecutor")ManagedExecutorService executor; And then the tasks are submitted using submit, invokeXXX or scheduleXXX methods. ScheduledFuture<?> future = executor.schedule(new MyTask(), 5, TimeUnit.SECONDS); This will create and execute a one-shot action that becomes enabled after 5 seconds of delay. More control is possible using one of the newly added methods: MyTaskListener implements ManagedTaskListener {  public void taskStarting(...) { . . . }  public void taskSubmitted(...) { . . . }  public void taskDone(...) { . . . }  public void taskAborted(...) { . . . } }ScheduledFuture<?> future = executor.schedule(new MyTask(), 5, TimeUnit.SECONDS, new MyTaskListener()); Here, ManagedTaskListener is used to monitor the state of a task's future. ManagedThreadFactory provides a method for creating threads for execution in a managed environment. A simple usage is: @Resource(name="concurrent/myThreadFactory")ManagedThreadFactory factory;. . .Thread thread = factory.newThread(new Runnable() { . . . }); concurrent/myThreadFactory is a JNDI resource. There is lot of interesting content in the Early Draft, download it, and read yourself. The implementation will be made available soon and also be integrated in GlassFish 4 as well. Some references for further exploring ... Javadoc Early Draft Specification concurrency-ee-spec.java.net [email protected]

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  • In 2011, what are the reasons to stick with plain text mails?

    - by Aaron Digulla
    People entering college today have never known a world without an Internet. HTML was invented 1980, that's more than thirty years ago or 1.5 generations. But plain text mails are still common despite all their problems: Encoding issues Wrapped code segments No links No way to use the "a picture says more than a thousand words" lore Most of the security risks are now handled by the underlying browser engine and smart settings like: Don't allow JavaScript in mails Don't execute attachments Don't download external resources (like web bugs) On top of that, only very few people still read mail only in command line tools like Mutt. Knowing Mutt myself, I'm pretty sure you can configure it to display HTML mail with, say, w3m. On top of that, most HTML mail capable clients send two versions of the mail (pure text with an HTML attachment). I'm not sure if there are any people left on the planet which still use a 56kbit modem to access their mail accounts. So what reasons are left to stick with plain text mails in 2011?

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  • added shell script to sudoers still getting permission denied

    - by Bill S
    I don't understand this? Other uses of sudo work fine. [oracle@o plugins]$ su Password: [root@ plugins]# su nrpe bash-3.2$ /home/oracle/obiee/instances/instance1/bifoundation/OracleBIApplication/coreapplication/setup/bi-init.sh bash: /home/oracle/obiee/instances/instance1/bifoundation/OracleBIApplication/coreapplication/setup/bi-init.sh: Permission denied bash-3.2$ sudo -l Matching Defaults entries for nrpe on this host: env_reset, env_keep="COLORS DISPLAY HOSTNAME HISTSIZE INPUTRC KDEDIR LS_COLORS MAIL PS1 PS2 QTDIR USERNAME LANG LC_ADDRESS LC_CTYPE LC_COLLATE LC_IDENTIFICATION LC_MEASUREMENT LC_MESSAGES LC_MONETARY LC_NAME LC_NUMERIC LC_PAPER LC_TELEPHONE LC_TIME LC_ALL LANGUAGE LINGUAS _XKB_CHARSET XAUTHORITY" Runas and Command-specific defaults for nrpe: User nrpe may run the following commands on this host: (ALL) NOPASSWD: /home/oracle/obiee/instances/instance1/bifoundation/OracleBIApplication/coreapplication/setup/bi-init.sh bash-3.2$

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  • Second Monitor Detected, but not receiving a signal after upgrading to 12.04

    - by user62458
    After I upgraded to 12.04, my second monitor is detected (in display settings), but will not power on. I have scoured the Internet and forums for a solution and I can't find anything. I have found a couple people with the same problem, but never a solution for it. I am no expert, but I'm certainly not a noob. My computer uses AMD Radeon 6250 graphics, but I do NOT want to use the proprietary graphics drivers. They refuse to work properly with my second monitor (they ATI drivers will only mirror screens, and I've done everything to try to fix it, and I DON't want mirrored screens) Not to mention that the default open-source video drivers seem to work much better than the proprietary anyway! Again, Ubuntu's default video drivers work fine, and they even DETECT the second monitor (Dell 19'). I can drag stuff off the screen and put it on the 'space' of the second monitor and even a screen-shot shows that there are two monitors active; but the monitor is OFF. It will not power on. It goes into 'power-save' mode because it is not receiving a signal. For some reason it is not getting the signal to power on, even though Ubuntu thinks the monitor is working properly. I had this working fine on my Sony VAIO yesterday (with Radeon graphics/default Ubuntu video drivers). I upgraded to a Samsung Series 3 and now I have this issue. I can't for the life of me figure out why the monitor is connected, detected and I have screen space for the monitor, but the screen won't turn on! XRANDR Output: Screen 0: minimum 320 x 200, current 1366 x 768, maximum 8192 x 8192 VGA-0 connected (normal left inverted right x axis y axis) 1440x900 59.9 + 75.0 1280x1024 75.0 60.0 1152x864 75.0 1024x768 75.1 70.1 60.0 832x624 74.6 800x600 72.2 75.0 60.3 56.2 640x480 72.8 75.0 66.7 60.0 720x400 70.1 LVDS connected 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 194mm 1366x768 60.1*+ 1280x720 59.9 1152x768 59.8 1024x768 59.9 800x600 59.9 848x480 59.7 720x480 59.7 640x480 59.4 HDMI-0 disconnected (normal left inverted right x axis y axis)

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  • mac osx software always order files alphabetically rather than by type.

    - by george
    i have noticed many mac applications sort the files alphabetically rather than by type. a good example would be coda by panic.com the files in the file menu are organized alphabetically, i requested for them to add the feature to organize files by type and they've said that its a finder thing. so i went in search to look at other applications to see if they were organizing by type i noticed dreamweaver cs4 had this same problem and now including dreamweaver cs5. there has to be something in the mac that does this and that i can modify. i played with spotlight and it now displays its files by type (thinking thats what i can do) but it didnt take affect in other applications. what library are these applications using to display a file menu for its files?

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  • How do I run vino-server without a monitor attached in Ubuntu 10.04

    - by Ole
    I just upgraded to Ubuntu 10.04 yesterday on a headless home server. I use the server for a variety of purposes, and what I don't know how to do via SSH I've alway been able to do through VNC. However, since the upgrade vino-server will no longer run if there isn't a monitor attached. Before it used to start up without a problem. Even by attempting to run the server via SSH gives me a "could not load display" error. Summary: I need to get vino-server running at boot time on a server with Ubuntu 10.04, without a monitor attached.

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  • How does one go about fixing a pixelation issue?

    - by Tyler
    I've been having a lot of trouble with pixelation and also in-game display driver crashes. At first I thought the problem may have been my graphics card (Sapphire 5750) but I have RMA'd it three times and I'm still having trouble. So what I think it might be is my PSU, its 650Watt but its made by Azza so it was cheap and not made by a necessarily good company. Or maybe it could be the CPU (AMD Phenom Black Edition 3.4Ghz) It runs hot (60C) but it passes Everest's test. Someone told me it could be the memory (8GB DDR3) but I don't really see how RAM has anything to do with my problem. So what are some of you suggestions? Here is a video a made awhile ago of what is happening. http://www.metacafe.com/watch/4392213/ati_radeon_5750/ That was just a stress test most games tend to just freeze and crash or lock my system up.

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  • The sign of a true manager is delegation (C# style)

    - by MarkPearl
    Today I thought I would write a bit about delegates in C#. Up till recently I have managed to side step any real understanding of what delegates do and why they are useful – I mean, I know roughly what they do and have used them a lot, but I have never really got down dirty with them and mucked about. Recently however with my renewed interest in Silverlight delegates came up again as a possible solution to a particular problem, and suddenly I found myself opening a bland little console application to just see exactly how far I could take delegates with my limited knowledge. So, let’s first look at the MSDN definition of delegates… A delegate declaration defines a reference type that can be used to encapsulate a method with a specific signature. A delegate instance encapsulates a static or an instance method. Delegates are roughly similar to function pointers in C++; however, delegates are type-safe and secure. Well, don’t you love MSDN for such a useful definition. I must give it credit though… later on it really explains it a bit better by saying “A delegate lets you pass a function as a parameter. The type safety of delegates requires the function you pass as a delegate to have the same signature as the delegate declaration.” A little more reading up on delegates mentions that delegates are similar to interfaces in that they enable the separation of specification and implementation. A delegate declares a single method, while an interface declares a group of methods. So enough reading - lets look at some code and see a basic example of a delegate… Let’s assume we have a console application with a simple delegate declared called AdjustValue like below… class Program { private delegate int AdjustValue(int val); static void Main(string[] args) { } } In a sense, all we have said is that we will be creating one or more methods that follow the same pattern as AdjustValue – i.e. they will take one input value of type int and return an integer. We could then expand our code to have various methods that match the structure of our delegate AdjustValue (remember the structure is int xxx (int xxx)) class Program { private delegate int AdjustValue(int val); private static int Dbl(int val) { return val * 2; } private static int AlwaysOne(int val) { return 1; } static void Main(string[] args) { } }  Above I have expanded my project to have two methods, one called Dbl and the other AlwaysOne. Dbl always returns double the input val and AlwaysOne always returns 1. I could now declare a variable and assign it to be one of those functions, like the following… class Program { private delegate int AdjustValue(int val); private static int Dbl(int val) { return val * 2; } private static int AlwaysOne(int val) { return 1; } static void Main(string[] args) { AdjustValue myDelegate; myDelegate = Dbl; Console.WriteLine(myDelegate(1).ToString()); Console.ReadLine(); } } In this instance I have declared an instance of the AdjustValue delegate called myDelegate; I have then told myDelegate to point to the method Dbl, and then called myDelegate(1). What would the result be? Yes, in this instance it would be exactly the same as me calling the following code… static void Main(string[] args) { Console.WriteLine(Dbl(1).ToString()); Console.ReadLine(); }   So why all the extra work for delegates when we could just do what we did above and call the method directly? Well… that separation of specification to implementation comes to mind. So, this all seems pretty simple. Let’s take a slightly more complicated variation to the console application. Assume that my project is the same as the one previously except that my main method is adjusted as follows… static void Main(string[] args) { AdjustValue myDelegate; myDelegate = Dbl; myDelegate = AlwaysOne; Console.WriteLine(myDelegate(1).ToString()); Console.ReadLine(); } What would happen in this scenario? Quite simply “1” would be written to the console, the reason being that myDelegate was last pointing to the AlwaysOne method before it was called. Make sense? In a way, the myDelegate is a variable method that can be swapped and changed when needed. Let’s make the code a little more confusing by using a delegate in the declaration of another delegate as shown below… class Program { private delegate int AdjustValue(InputValue val); private delegate int InputValue(); private static int Dbl(InputValue val) { return val()*2; } private static int GetInputVal() { Console.WriteLine("Enter a whole number : "); return Convert.ToInt32(Console.ReadLine()); } static void Main(string[] args) { AdjustValue myDelegate; myDelegate = Dbl; Console.WriteLine(myDelegate(GetInputVal).ToString()); Console.ReadLine(); } }   Now it gets really interesting because it looks like we have passed a method into a function in the main method by declaring… Console.WriteLine(myDelegate(GetInputVal).ToString()); So, what it the output? Well, try take a guess on what will happen – then copy the code and see if you got it right. Well that brings me to the end of this short explanation of Delegates. Hopefully it made sense!

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  • What is the program "Additional Drivers" (jockey-gtk) talking me about?

    - by Robert Vila
    The program says: "No proprietary drivers are in use on this system" But it doesn't say if it is talking about graphical drivers only or what. Then, it lists two drivers: NVIDIA accelerated graphics driver (version 173). NVIDIA accelerated graphics driver (version current) [recomended] Both have exactly the same description. What is the difference then? When I select the 1st one, it says: "This river is not activated",and there's a button to "activate" it. When I select the 2nd one, it says: "This river is activated but it is not currently in use", and the button is to "remove". So which one is in use? Why or what for should I have activated (enabled) and not in use? If it is in use it is activated? What is the difference between activate and remove? and what is the relationship between installed, activated, in use, enabled and removed, disabled, inactive and not-installed? Why can I activate the inactivated and remove (but not deactivate) the activated that is not in use? All this is very puzzling... What other drivers can I use for an Apple MacBook pro 3,1 and how? I see that there's a nouveau and I heard that there was going to be a new open source even better. > -display > description: VGA compatible controller > product: G84 [GeForce 8600M GT] > vendor: nVidia Corporation

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  • jBullet Collision/Physics not working as expected

    - by Kenneth Bray
    Below is the code for one of my objects in the game I am creating (yes although this is a cube, I am not making anything remotely like MineCraft), and my issue is I while the cube will display and is does follow the physics if the cube falls, it does not interact with any other objects in the game. If I was to have multiple cubes in screen at once they all just sit there, or shoot off in all directions never stopping. Anyway, I am new to jBullet, and any help would be appreciated. // Constructor public Cube(float pX, float pY, float pZ, float pSize) { posX = pX; posY = pY; posZ = pZ; size = pSize; rotX = 0; rotY = 0; rotZ = 0; // physics stuff fallMotionState = new DefaultMotionState(new Transform(new Matrix4f(new Quat4f(0, 0, 0, 1), new Vector3f(posX, posY, posZ), 1))); fallRigidBodyCI = new RigidBodyConstructionInfo(mass, fallMotionState, fallShape, fallInertia); fallRigidBody = new RigidBody(fallRigidBodyCI); }

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  • How to force 640*480@60Hz screen resolution on xubuntu 12.04

    - by c2h2
    It seems xubuntu won't be able to correctly set resolution at 640*480@60Hz at its Display settings. And I am unable to correctly my super small 6.4 inch Mitsubishi VGA panel via VGA cable. I have tried to hack both X11 conf /etc/X11/Xorg.conf and xfce4 conf, but all the document I can find is outdated. and conf files are changed into other location. Can someone give me a hand and I'll mark correct for other people to use? Thanks! EDIT: The board is an Intel Atom D2700, gpu is SGX545. I tried to use xrandr --output default --mode 640*480 It seems works fine, but refresh rate is 75Hz, but the screen only suports 60Hz So I used xrandr --output default --mode 640*480 --rate 60 but it give error: xrandr: Failed to get size of gamma for output default Can anyone pointing any directions?

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  • Can a custom DPI setting be applied to Remote Desktop sessions?

    - by sejong
    Can a custom DPI setting be applied to Remote Desktop sessions? When you try to change the DPI from a Remote Desktop session, you get a message that display settings can't be changed from a remote session. That made me think that changing DPI from a console setting would work. It did, sort of. If I connected via Remote Desktop to an existing console session with a custom DPI setting, that setting would be applied to the Remote Desktop session. However, if I logged off that session, the custom DPI would not be applied to subsequent Remote Desktop sessions even though it was maintained for subsequent console sessions. It looks like the registry value HKEY_CURRENT_USER\Control Panel\Desktop\WindowMetrics\AppliedDPI (and perhaps other values) is overwritten at logon, but I haven't been able figure out how to prevent it.

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