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  • Head Rotation in Opposite Direction with GLM and Oculus Rift SDK

    - by user3434662
    I am 90% there in getting orientation to work. I am just trying to resolve one last bit and I hope someone can point me to any easy errors I am making but not seeing. My code works except when a person looks left the camera actually rotates right. Vice versa with looking right, camera rotates left. Any idea what I am doing wrong here? I retrieve the orientation from the Oculus Rift like so: OVR::Quatf OculusRiftOrientation = PredictedPose.Orientation; glm::vec3 CurrentEulerAngles; glm::quat CurrentOrientation; OculusRiftOrientation.GetEulerAngles<OVR::Axis_X, OVR::Axis_Y, OVR::Axis_Z, OVR::Rotate_CW, OVR::Handed_R> (&CurrentEulerAngles.x, &CurrentEulerAngles.y, &CurrentEulerAngles.z); CurrentOrientation = glm::quat(CurrentEulerAngles); And here is how I calculate the LookAt: /* DirectionOfWhereCameraIsFacing is calculated from mouse and standing position so that you are not constantly rotating after you move your head. */ glm::vec3 DirectionOfWhereCameraIsFacing; glm::vec3 RiftDirectionOfWhereCameraIsFacing; glm::vec3 RiftCenterOfWhatIsBeingLookedAt; glm::vec3 PositionOfEyesOfPerson; glm::vec3 CenterOfWhatIsBeingLookedAt; glm::vec3 CameraPositionDelta; RiftDirectionOfWhereCameraIsFacing = DirectionOfWhereCameraIsFacing; RiftDirectionOfWhereCameraIsFacing = glm::rotate(CurrentOrientation, DirectionOfWhereCameraIsFacing); PositionOfEyesOfPerson += CameraPositionDelta; CenterOfWhatIsBeingLookedAt = PositionOfEyesOfPerson + DirectionOfWhereCameraIsFacing * 1.0f; RiftCenterOfWhatIsBeingLookedAt = PositionOfEyesOfPerson + RiftDirectionOfWhereCameraIsFacing * 1.0f; RiftView = glm::lookAt(PositionOfEyesOfPerson, RiftCenterOfWhatIsBeingLookedAt, DirectionOfUpForPerson);

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  • Advantages of Using Linux as primary developer desktop

    - by Nick N
    I want to get some input on some of the advantages of why developers should and need to use Linux as their primary development desktop on a daily basic as opposed to using Windows. This is particulary helpful when your Dev, QA, and Production environments are Linux. The current analogy that I keep coming back to is. If I build my demo car as a Ford Escort, but my project car is a Ford Mustang, it doesn't make sense at all. I'm currently at an IT department that allows dual boot with Windows and Linux, but some run Linux while the vast majority use Windows. Here's several advantages that I've came up with since using Linux as a primary desktop. Same Exact operating system as Dev, QA, and Production Same Scripts (.sh) instead of maintaining (.bat and *.sh). Somewhat mitigated by using cygwin, but still a bit different. Team learns simple commands such as: cd, ls, cat, top Team learns Advanced commands like: pkill, pgrep, chmod, su, sudo, ssh, scp Full access to installs typically for Linux, such as RPM, DEB installs just like the target environments. The list could go on and on, but I want to get some feedback of anything that I may have missed, or even any disadvantages (of course there are some). To me it makes sense to migrate an entire team over to using Linux, and using Virtual Box, running Windows XP VM's to test functional items that 95% of most of the world uses. This is similar but a little different thread going on here as well. link text

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  • Which source control paradigm and solution to embed in a custom editor application?

    - by Greg Harman
    I am building an application that manages a number of custom objects, which may be edited concurrently by multiple users (using different instances of the application). These objects have an underlying serialized representation, and my plan is to persist them (through my application UI) in an external source control system. Of course this implies that my application can check the current version of an object for updates, a merging interface for each object, etc. My question is what source control paradigm(s) and specific solution(s) to support and why. The way I (perhaps naively) see the source control world is three general paradigms: Single-repository, locked access (MS SourceSafe) Single-repository, concurrent access (CVS/SVN) Distributed (Mercurial, Git) I haven't heard of anyone using #1 for quite a number of years, so I am planning to disregard this case altogether (unless I get a compelling argument otherwise). However, I'm at a loss as to whether to support #2 or #3, and which specific implementations. I'm concerned that the use paradigms are subtly different enough that I can't adequately capture basic operations in a single UI. The last bit of information I should convey is that this application is intended to be deployed in a commercial setting, where a source control system may already be in use. I would prefer not to support more than one solution unless it's really a deal-breaker, so wide adoption in a corporate setting is a plus.

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  • Should I use two queries, or is there a way to JOIN this in MySQL/PHP?

    - by Jack W-H
    Morning y'all! Basically, I'm using a table to store my main data - called 'Code' - a table called 'Tags' to store the tags for each code entry, and a table called 'code_tags' to intersect it. There's also a table called 'users' which stores information about the users who submitted each bit of code. On my homepage, I want 5 results returned from the database. Each returned result needs to list the code's title, summary, and then fetch the author's firstname based on the ID of the person who submitted it. I've managed to achieve this much so far (woot!). My problem lies when I try to collect all the tags as well. At the moment this is a pretty big query and it's scaring me a little. Here's my problematic query: SELECT code.*, code_tags.*, tags.*, users.firstname AS authorname, users.id AS authorid FROM code, code_tags, tags, users WHERE users.id = code.author AND code_tags.code_id = code.id AND tags.id = code_tags.tag_id ORDER BY date DESC LIMIT 0, 5 What it returns is correct looking data, but several repeated rows for each tag. So for example if a Code entry has 3 tags, it will return an identical row 3 times - except in each of the three returned rows, the tag changes. Does that make sense? How would I go about changing this? Thanks! Jack

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  • How do I know which include path will be used in PHP?

    - by Joe Majewski
    When I run phpinfo() and look by the Configuration category under PHP Core, I see a directive titled include_path, with a local value and a master value. In this case, my local value is set to .: ./include: ../include: /usr/share/php: /usr/share/php/smarty: /usr/share/pear and my master value is set to .: /usr/share/php: /usr/share/pear: /usr/share/php/pear: /usr/share/php/smarty The reason I am trying to learn how this works is because there is a file in the system I am working on titled Smarty.class.php, which I'm sure sounds very familiar to anyone who uses Smarty Templating Engine. One of the PHP files has the following includes: require_once("Smarty.class.php"); require_once("user_info_class.inc"); The file user_info_class.inc is in the same directory as the file making the include, which makes perfect sense to me, and is the way that I've always referenced files. I decided that I wanted to open up the Smarty.class.php file and had assumed it would be in the same directory, but it was not. After doing a bit of digging, I discovered those php_ini variables, and was finally able to locate the file in the directory usr/share/php/smarty/. So it would seem that when making an include, it follows some sort of order between the Local and Master values for the include_path. Assuming that my deductions were correct thus far, can someone explain the order in which PHP searches for the files to be included?

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  • How to get the output of an XslCompiledTransform into an XmlReader?

    - by Graham Clark
    I have an XslCompiledTransform object, and I want the output in an XmlReader object, as I need to pass it through a second stylesheet. I'm getting a bit confused - I can successfully transform some XML and read it using either a StreamReader or an XmlDocument, but when I try an XmlReader, I get nothing. In the example below, stylesheet is my XslCompiledTransform object. The first two Console.WriteLine calls output the correct transformed XML, but the third call gives no XML. I'm guessing it might be that the XmlTextReader is expecting text, so maybe I need to wrap this in a StreamReader..? What am I doing wrong? MemoryStream transformed = new MemoryStream(); stylesheet.Transform(input, args, transformed); transformed.Position = 0; StreamReader s = new StreamReader(transformed); Console.WriteLine("s = " + s.ReadToEnd()); // writes XML transformed.Position = 0; XmlDocument doc = new XmlDocument(); doc.Load(transformed); Console.WriteLine("doc = " + doc.OuterXml); // writes XML transformed.Position = 0; XmlReader reader = new XmlTextReader(transformed); Console.WriteLine("reader = " + reader.ReadOuterXml()); // no XML written

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  • why am I stuck on "Initiating update" when deploying to google

    - by michelle
    I've have not had any trouble deploying through eclipse until now. I'm guessing it might have to do with all the stuff I've added today a folder of .pdf and .tex files (in war/web-inf directory) a bit of JDO stuff and a servlet that reads the files in the directory and indexes them into the JDO Is there any way to find out what exactly is the problem? I currently get stuck at "Initiating update" and the stack trace say "ConnectionReset" Any helkp of imput will be appreciated, I really need to deploy this today, thanks! here's the deploy trace: Unable to update: java.net.SocketException: Connection reset at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) at java.lang.reflect.Constructor.newInstance(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection$6.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at sun.net.www.protocol.http.HttpURLConnection.getChainedException(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source) at java.net.HttpURLConnection.getResponseCode(Unknown Source) at com.google.appengine.tools.admin.ServerConnection.getAuthCookie(ServerConnection.java:315) at com.google.appengine.tools.admin.ServerConnection.authenticate(ServerConnection.java:219) at com.google.appengine.tools.admin.ServerConnection.send(ServerConnection.java:145) at com.google.appengine.tools.admin.ServerConnection.post(ServerConnection.java:81) at com.google.appengine.tools.admin.AppVersionUpload.send(AppVersionUpload.java:427) at com.google.appengine.tools.admin.AppVersionUpload.beginTransaction(AppVersionUpload.java:241) at com.google.appengine.tools.admin.AppVersionUpload.doUpload(AppVersionUpload.java:98) at com.google.appengine.tools.admin.AppAdminImpl.update(AppAdminImpl.java:56) at com.google.appengine.eclipse.core.proxy.AppEngineBridgeImpl.deploy(AppEngineBridgeImpl.java:271) at com.google.appengine.eclipse.core.deploy.DeployProjectJob.runInWorkspace(DeployProjectJob.java:148) at org.eclipse.core.internal.resources.InternalWorkspaceJob.run(InternalWorkspaceJob.java:38) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55) Caused by: java.net.SocketException: Connection reset at java.net.SocketInputStream.read(Unknown Source) at java.io.BufferedInputStream.fill(Unknown Source) at java.io.BufferedInputStream.read1(Unknown Source) at java.io.BufferedInputStream.read(Unknown Source) at sun.net.www.http.HttpClient.parseHTTPHeader(Unknown Source) at sun.net.www.http.HttpClient.parseHTTP(Unknown Source) at sun.net.www.http.HttpClient.parseHTTP(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source) at sun.net.www.protocol.http.HttpURLConnection.getHeaderFieldKey(Unknown Source) at com.google.appengine.tools.util.ClientCookieManager.readCookies(ClientCookieManager.java:123) at com.google.appengine.tools.admin.ServerConnection.connect(ServerConnection.java:340) at com.google.appengine.tools.admin.ServerConnection.getAuthCookie(ServerConnection.java:314) ... 11 more

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  • Kernighan & Ritchie word count example program in a functional language

    - by Frank
    I have been reading a little bit about functional programming on the web lately and I think I got a basic idea about the concepts behind it. I'm curious how everyday programming problems which involve some kind of state are solved in a pure functional programing language. For example: how would the word count program from the book 'The C programming Language' be implemented in a pure functional language? Any contributions are welcome as long as the solution is in a pure functional style. Here's the word count C code from the book: #include <stdio.h> #define IN 1 /* inside a word */ #define OUT 0 /* outside a word */ /* count lines, words, and characters in input */ main() { int c, nl, nw, nc, state; state = OUT; nl = nw = nc = 0; while ((c = getchar()) != EOF) { ++nc; if (c == '\n') ++nl; if (c == ' ' || c == '\n' || c = '\t') state = OUT; else if (state == OUT) { state = IN; ++nw; } } printf("%d %d %d\n", nl, nw, nc); }

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  • Cairo / GTK example code crashes when window is too big or maximized

    - by user1890673
    I have copied and compiled the source code available in the section titled "Full Source". http://cairographics.org/threaded_animation_with_cairo/ I adapted this code to a project that I'm working on only to find that the app would crash when I made the window too big. Going back to the original example code, it too crashes when the window is too big ( 1000x1000 or so). I narrowed down in the example that this line appears to be responsible: pixmap = gdk_pixmap_new(window-window,500,500,-1); Where pixmap is of type GdkPixmap*. Resizing the window overwrites pixmap with a new pixmap that is the size of the window. I am doing this in Eclipse Juno in Windows Vista, 32-bit. My compiler is MinGW version 0.5-beta-20120426-1. My GTK+ version is 2.24.10 and apparently Cairo is 1.10.2 I added all of the includes and libraries for GTK and also added compiler switch -mms-bitfields. Is there a limit to the size of a pixmap or something? I'm just starting with GTK with examples so I'm not sure where to go if this example doesn't work.

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  • Inserting bits into byte

    - by JB_SO
    I was looking at an example of reading bits from a byte and the implementation looked simple and easy to understand. I was wondering if anyone has a similar example of how to insert bits into a byte or byte array, that is easier to understand and also implement like the example below. Here is the example I found of reading bits from a byte (http://bytes.com/topic/c-sharp/answers/505085-reading-bits-byte-file): static int GetBits3(byte b, int offset, int count) { return (b >> offset) & ((1 << count) - 1); } Here is what i'm trying to do....and this is my current implementation.....just a little confused with the bit-masking/shifting, etc, that's why I'm trying to find out if there is an easier way to do what i'm doing BYTE Msg[2]; Msg_Id = 3; Msg_Event = 1; Msg_Ready = 2; Msg[0] = ( ( Msg_Event << 4 ) & 0xF0 ) | ( Msg_Id & 0x0F ) ; Msg[1] = Msg_Ready & 0x0F; //MsgReady & Unused Thanks for your help!

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  • Suggested (simple) approach for drawing large numbers of visual elements in WPF?

    - by Ender
    I'm writing an interface that features a large (~50000px width) "canvas"-type area that is used to display a lot of data in a fairly novel way. This involves lots of lines, rectangles, and text. The user can scroll around to explore the entire canvas. At the moment I'm just using a standard Canvas panel with various Shapes placed on it. This is nice and easy to do: construct a shape, assign some coordinates, and attach it to the Canvas. Unfortunately, it's pretty slow (to construct the children, not to do the actual rendering). I've looked into some alternatives, it's a bit intimidating. I don't need anything fancy - just the ability to efficiently construct and place objects in a coordinate plane. If all I get are lines, colored rectangles, and text, I'll be happy. Do I need Geometry instances inside of Geometry Groups inside of GeometryDrawings inside of some Panel container? Note: I'd like to include text and graphics (i.e. colored rectangles) in the same space, if possible.

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  • Is this a variation of the traveling salesman problem?

    - by Ville Koskinen
    I'm interested in a function of two word lists, which would return an order agnostic edit distance between them. That is, the arguments would be two lists of (let's say space delimited) words and return value would be the minimum sum of the edit (or Levenshtein) distances of the words in the lists. Distance between "cat rat bat" and "rat bat cat" would be 0. Distance between "cat rat bat" and "fat had bad" would be the same as distance between "rat bat cat" and "had fat bad", 4. In the case the number of words in the lists are not the same, the shorter list would be padded with 0-length words. My intuition (which hasn't been nurtured with computer science classes) does not find any other solution than to use brute force: |had|fat|bad| a solution ---+---+---+---+ +---+---+---+ cat| 2 | 1 | 2 | | | 1 | | ---+---+---+---+ +---+---+---+ rat| 2 | 1 | 2 | | 3 | | | ---+---+---+---+ +---+---+---+ bat| 2 | 1 | 1 | | | | 4 | ---+---+---+---+ +---+---+---+ Starting from the first row, pick a column and go to the next rows without ever revisiting a column you have already visited. Do this over and over again until you've tried all combinations. To me this sounds a bit like the traveling salesman problem. Is it, and how would you solve my particular problem?

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  • Fast sketching tools for drawing C/C++ structs, pointers, etc...

    - by tomasorti
    Hi. I would like to know what do you use to sketch relations between different entities in C/C++. This can be a very broad issue, so I'll try to clarify a bit more my question and give an example. I'm looking for something that is simple enough as a user, and let me sketch easily containers, pointers, etc... in an informal way. The aim is to document some structs relations to pass them to junior developers. A look at the drawings is supposed to accelerate the understanding of the code. My solutions at this moment are to use: 1) Paper & pencil. 2) Microsoft PowerPoint/Word Autoshapes. 3) Freeware Dia. Other ones could be: 4) Microsoft Visio, but my company does not own licenses. 5) UML tools. I don't want to go this way. This is what I mean a more formal solution. I know tools like Rational Rose are great, and I tried boUML and violet and they are fine in some parts, but I prefer the flexibility of options 2) or 3). Finally, let me write down a more concrete example: Let's say I what to sketch a map that contains another map as the mapped value, and that one contains a struct as the mapped value, that holds a vector of pointers of a type and a pointer to other type. Also, there exist other structs that hold pointers to the objects pointed by the previous map, so there are objects pointed from different places. This is just one example I have, but you can easily come with one from you experience. What would you use to sketch this example or another similar you have dealt with? Best regards, Tomas.

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  • ApplicationPoolIdentity permissions on Temporary Asp.Net files

    - by Anton
    Hi all, at work I am struggling a bit with the following situation: We have a web application that runs on a WIndows Server 2008 64 bits machine. The app's ApplicationPool is running under the ApplicationPoolIdentity and configured for .net 2 and Classic pipeline mode. This works fine up to the moment that XmlSerialization requires creation of Serializer assemblies where MEF is being used to create a collection of knowntypes. To remedy this I was hoping that granting the ApplicationPoolIdentity rights to the ASP.Net Temporary Files directory would be enough, but alas... What I did was the run the following command from a cmd prompt: icacls "c:\windows\microsoft.net\framework64\v2.0.50727\Temporary ASP.NET Files" /grant "IIS AppPool\MyAppPool":(M) Obviously this did not work, otherwise you would not be reading this :) Strange thing is that whenever I grant the Users or even more specific, the Authenticated Users Group those permissions, it works. What's weird as well (in my eyes) is that before I started granting access the ApplicationPoolIdentity was already a member of IIS_IUSRS which does have Modify rights for the temporary asp files directory. And now I'm left wondering why this situation requires Modify rights for the Authenticated Users group. I thought it could be because the apppool account was missing additional rights (googling for this returned some results, so I tried those), but granting the ApplicationPoolIdentity modification rights to the Windows\Temp directory and/or the application directory itself did not fix it. For now we have a workaround, but I hate that I don't know what is exactly going on here, so I was hoping any of you guys could shed some light on this. Thanx in advance!

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  • Namespace constants and use as

    - by GordonM
    I'm having some problems with using constants from a namespace. If I define the constant and try to use as it, PHP seems unable to find it. For example, in my file with the constants I have code along the lines of the following: namespace \my\namespace\for\constants; const DS = DIRECTORY_SEPARATOR; Then in the consuming file I have: namespace \some\other\namespace; use \my\namespace\for\constants\DS as DS; echo (realpath (DS . 'usr' . DS 'local')); However, instead of echoing '/usr/local' as expected I get the following notice and an empty string. Notice: Use of undefined constant DS - assumed 'DS' If I change the code as follows: use \my\namespace\for\constants as cns; echo (realpath (cns\DS . 'usr' . cns\DS 'local')); I get the expected result, but it's obviously quite a bit less convenient than just being able to pull the constants in directly. You can alias a class/interface/trait in a namespace, are you not able to alias a constant too? If you can do it, then how?

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  • How to access elements in a complex list?

    - by Martin
    Hi, it's me and the lists again. I have a nice list, which looks like this: tmp = NULL t = NULL tmp$resultitem$count = "1057230" tmp$resultitem$status = "Ok" tmp$resultitem$menu = "PubMed" tmp$resultitem$dbname = "pubmed" t$resultitem$count = "305215" t$resultitem$status = "Ok" t$resultitem$menu = "PMC" t$resultitem$dbname = "pmc" tmp = c(tmp, t) t = NULL t$resultitem$count = "1" t$resultitem$status = "Ok" t$resultitem$menu = "Journals" t$resultitem$dbname = "journals" tmp = c(tmp, t) Which produces: str(tmp) List of 3 $ resultitem:List of 4 ..$ count : chr "1057230" ..$ status: chr "Ok" ..$ menu : chr "PubMed" ..$ dbname: chr "pubmed" $ resultitem:List of 4 ..$ count : chr "305215" ..$ status: chr "Ok" ..$ menu : chr "PMC" ..$ dbname: chr "pmc" $ resultitem:List of 4 ..$ count : chr "1" ..$ status: chr "Ok" ..$ menu : chr "Journals" ..$ dbname: chr "journals" Now I want to search through the elements of each "resultitem". I want to know the "dbname" for every database, that has less then 10 "count" (example). In this case it is very easy, as this list only has 3 elements, but the real list is a little bit longer. This could be simply done with a for loop. But is there a way to do this with some other function of R (like rapply)? My problem with those apply functions is, that they only look at one element. If I do a grep to get all "dbname" elements, I can not get the count of each element. rapply(tmp, function(x) paste("Content: ", x))[grep("dbname", names(rapply(tmp, c)))] Does someone has a better idea than a for loop? Thanx, Martin

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  • Flash CS4 [AS3]: Playing Card Deck Array

    - by Ben
    I am looking to make a card game in Flash CS4 using AS3 and I am stuck on the very first step. I have created graphics for a standard 52 card deck of playing cards and imported them into the library in Flash and then proceeded to convert them all to Movie Clips. I have also used the linkage to make them available in the code. The movie clips and the linkage are named in sequence, as in the Ace of Clubs would be C1, two of Diamonds is called D2, Jack of Spades is S11. (C = Clubs, D = Diamonds, S = Spades, H = Hearts and numbers 1 through 13 are the card values. 1 being Ace, 11 being Jack, 12 being Queen, 13 being King). As far as I know my next step would be to arrange the cards into an array. This is the part that I am having problems with. Can someone please point me in the right direction, what would be the best way to do this. Could you provide me with a bit of sample code as well? I have had a look at few tutorials online but they are all telling me different things, some are incomplete and the rest...well...they're just cr*ppy. Thanks in advance! Ben

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  • Adding jQuery event handler to expand div when a link is clicked

    - by hollyb
    I'm using a bit of jQuery to expand/hide some divs. I need to add an event handler so that when a link is clicked, it opens a corrisponding div. Each toggled div will have a unique class assigned to it. I am looking for some advice about how to build the event handler. The jQuery $(document).ready(function(){ $(".toggle_container:not(:first)").hide(); $(".toggle_container:first").show(); $("h6.trigger:first").addClass("active"); $("h6.trigger").click(function(){ $(this).toggleClass("active"); $(this).next(".toggle_container").slideToggle(300); }); The css: // uses a background image with an on (+) and off (-) state stacked on top of each other h6.trigger { background: url(buttonBG.gif) no-repeat;height: 46px;line-height: 46px;width: 300px;font-size: 2em;font-weight: normal;} h6.trigger a {color: #fff;text-decoration: none; display: block;} h6.active {background-position: left bottom;} .toggle_container { overflow: hidden; } .toggle_container .block {padding: 20px;} The html has a list of links, such as: <a href="#">One</a> <a href="#">Two</a> and the coorisponding divs to open: <h6 class="trigger">Container one</h6> <div class="toggle_container"> div one </div> <h6 class="trigger">Container two</h6> <div class="toggle_container Open"> div one </div> As I mentioned, I will be assigning a unique class to facilitate this. Any advice? Thanks! To clarify, i'm looking for some advice to build an event handler to toggle open a specific div when a link is clicked from a different part of the page, from a nav for instance.

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  • Prevent two users from editing the same data

    - by Industrial
    Hi everyone, I have seen a feature in different web applications including Wordpress (not sure?) that warns a user if he/she opens an article/post/page/whatever from the database, while someone else is editing the same data simultaneously. I would like to implement the same feature in my own application and I have given this a bit of thought. Is the following example a good practice on how to do this? It goes a little something like this: 1) User A enters a the editing page for the mysterious article X. The database tableEvents is queried to make sure that no one else is editing the same page for the moment, which no one is by then. A token is then randomly being generated and is inserted into a database table called Events. 1) User B also want's to make updates to the article X. Now since our User A already is editing the article, the Events table is queried and looks like this: | timestamp | owner | Origin | token | ------------------------------------------------------------ | 1273226321 | User A | article-x | uniqueid## | 2) The timestamp is being checked. If it's valid and less than say 100 seconds old, a message appears and the user cannot make any changes to the requested article X: Warning: User A is currently working with this article. In the meantime, editing cannot be done. Please do something else with your life. 3) If User A decides to go on and save his changes, the token is posted along with all other data to update the database, and toggles a query to delete the row with token uniqueid##. If he decides to do something else instead of committing his changes, the article X will still be available for editing in 100 seconds for User B Let me know what you think about this approach! Wish everyone a great weekend!

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  • What's the boost way to create a functor that binds out an argument

    - by Mordachai
    I have need for a function pointer that takes two arguments and returns a string. I would like to pass an adapter that wraps a function that takes one argument, and returns the string (i.e. discard one of the arguments). I can trivially build my own adapter, that takes the 2 arguments, calls the wrapped function passing just the one argument through. But I'd much rather have a simple way to create an adapter on the fly, if there is an easy way to do so in C++/boost? Here's some details to make this a bit more concrete: typedef boost::function<CString (int,int)> TooltipTextFn; class MyCtrl { public: MyCtrl(TooltipTextFn callback = boost::bind(&MyCtrl::GetCellText, this, _1, _2)) : m_callback(callback) { } // QUESTION: how to trivially wrapper GetRowText to conform to TooltipTextFn by just discarding _2 ?! void UseRowText() { m_callback = boost::bind(&MyCtrl::GetRowText, this, _1, ??); } private: CString GetCellText(int row, int column); CString GetRowText(int row); TooltipTextFn m_callback; } Obviously, I can supply a member that adapts GetRowText to take two arguments and only passes the first to GetRowText() itself. But is there already a boost binder / adapter that lets me do that?

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  • Delphi - Help calling threaded dll function from another thread

    - by cloudstrif3
    I'm using Delphi 2006 and have a bit of a problem with an application I'm developing. I have a form that creates a thread which calls a function that performs a lengthy operation, lets call it LengthyProcess. Inside the LengthyProcess function we also call several Dll functions which also create threads of their own. The problem that I am having is that if I don't use the Synchronize function of my thread to call LengthyProcess the thread stops responding (the main thread is still responding fine). I don't want to use Synchronize because that means the main thread is waiting for LengthyProcess to finish and therefore defeats the purpose of creating a separate thread. I have tracked the problem down to a function inside the dll that creates a thread and then calls WaitFor, this is all done using TThread by the way. WaitFor checks to see if the CurrentThreadID is equal to the MainThreadID and if it is then it will call CheckSychronization, and all is fine. So if we use Synchronize then the CurrentThreadID will equal the MainThreadID however if we do not use Synchronize then of course CurrentThreadID < MainThreadID, and when this happens WaitFor tells the current thread (the thread I created) to wait for the thread created by the DLL and so CheckSynchronization never gets called and my thread ends up waiting forever for the thread created in the dll. I hope this makes sense, sorry I don't know any better way to explain it. Has anyone else had this issue and knows how to solve it please?

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  • DataSets to POCOs - an inquiry regarding DAL architecture

    - by alexsome
    Hello all, I have to develop a fairly large ASP.NET MVC project very quickly and I would like to get some opinions on my DAL design to make sure nothing will come back to bite me since the BL is likely to get pretty complex. A bit of background: I am working with an Oracle backend so the built-in LINQ to SQL is out; I also need to use production-level libraries so the Oracle EF provider project is out; finally, I am unable to use any GPL or LGPL code (Apache, MS-PL, BSD are okay) so NHibernate/Castle Project are out. I would prefer - if at all possible - to avoid dishing out money but I am more concerned about implementing the right solution. To summarize, there are my requirements: Oracle backend Rapid development (L)GPL-free Free I'm reasonably happy with DataSets but I would benefit from using POCOs as an intermediary between DataSets and views. Who knows, maybe at some point another DAL solution will show up and I will get the time to switch it out (yeah, right). So, while I could use LINQ to convert my DataSets to IQueryable, I would like to have a generic solution so I don't have to write a custom query for each class. I'm tinkering with reflection right now, but in the meantime I have two questions: Are there any problems I overlooked with this solution? Are there any other approaches you would recommend to convert DataSets to POCOs? Thanks in advance.

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  • Execute Stored Procedure from Classic ASP

    - by Jaco Pretorius
    For some fantastic reason I find myself debugging a problem in a Classic ASP page (at least 10 years of my life lost in the last 2 days). I'm trying to execute a stored procedure which contains some OUT parameters. The problem is that one of the OUT parameters is not being populated when the stored procedure returns. I can execute the stored proc from SQL management studio (this is 2008) and all the values are being set and returned exactly as expected. declare @inVar1 varchar(255) declare @inVar2 varchar(255) declare @outVar1 varchar(255) declare @outVar2 varchar(255) SET @inVar2 = 'someValue' exec theStoredProc @inVar1 , @inVar2 , @outVar1 OUT, @outVar2 OUT print '@outVar1=' + @outVar1 print '@outVar2=' + @outVar2 Works great. Fantastic. Perfect. The exact values that I'm expecting are being returned and printed out. Right, since I'm trying to debug a Classic ASP page I copied the code into a VBScript file to try and narrow down the problem. Here is what I came up with: Set Conn = CreateObject("ADODB.Connection") Conn.Open "xxx" Set objCommandSec = CreateObject("ADODB.Command") objCommandSec.ActiveConnection = Conn objCommandSec.CommandType = 4 objCommandSec.CommandText = "theStoredProc " objCommandSec.Parameters.Refresh objCommandSec.Parameters(2) = "someValue" objCommandSec.Execute MsgBox(objCommandSec.Parameters(3)) Doesn't work. Not even a little bit. (Another ten years of my life down the drain) The third parameter is simply NULL - which is what I'm experiencing in the Classic ASP page as well. Could someone shed some light on this? Am I completely daft for thinking that the classic ASP code would be the same as the VBScript code? I think it's using the same scripting engine and syntax so I should be ok, but I'm not 100% sure. The result I'm seeing from my VBScript is the same as I'm seeing in ASP.

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  • SQL Server - stored procedure suddenly become slow

    - by Barguast
    I have written a stored procedure that, yesterday, typically completed in under a second. Today, it takes about 18 seconds. I ran into the problem yesterday as well, and it seemed to be solved by DROPing and re-CREATEing the stored procedure. Today, that trick doesn't appear to be working. :( Interestingly, if I copy the body of the stored procedure and execute it as a straightforward query it completes quickly. It seems to be the fact that it's a stored procedure that's slowing it down...! Does anyone know what the problem might be? I've searched for answers, but often they recommend running it through Query Analyser, but I don't have have it - I'm using SQL Server 2008 Express for now. The stored procedure is as follows; ALTER PROCEDURE [dbo].[spGetPOIs] @lat1 float, @lon1 float, @lat2 float, @lon2 float, @minLOD tinyint, @maxLOD tinyint, @exact bit AS BEGIN -- Create the query rectangle as a polygon DECLARE @bounds geography; SET @bounds = dbo.fnGetRectangleGeographyFromLatLons(@lat1, @lon1, @lat2, @lon2); -- Perform the selection if (@exact = 0) BEGIN SELECT [ID], [Name], [Type], [Data], [MinLOD], [MaxLOD], [Location].[Lat] AS [Latitude], [Location].[Long] AS [Longitude], [SourceID] FROM [POIs] WHERE NOT ((@maxLOD < [MinLOD]) OR (@minLOD > [MaxLOD])) AND (@bounds.Filter([Location]) = 1) END ELSE BEGIN SELECT [ID], [Name], [Type], [Data], [MinLOD], [MaxLOD], [Location].[Lat] AS [Latitude], [Location].[Long] AS [Longitude], [SourceID] FROM [POIs] WHERE NOT ((@maxLOD < [MinLOD]) OR (@minLOD > [MaxLOD])) AND (@bounds.STIntersects([Location]) = 1) END END The 'POI' table has an index on MinLOD, MaxLOD, and a spatial index on Location.

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  • Objective-C and NSURL: where am I supposed to declare receivedData?

    - by jthomas
    I have a two classes, a controller called "AppController" and a class called "URLDelegate" that encapsulates the sample NSURL code from Apple's URL Loading System Programming Guide. The guide repeatedly mentions declaring the receivedData instance variable "elsewhere." I assume this means outside of the URLDelagate class, because if I declare it in the URLDelegate class, my controller class can't "see" the data that has been downloaded. I know that data is received, because in my connectionDidFinishLoading function, I have NSLog display the results: NSLog(@"Succeeded! Received %d bytes of data",[receivedData length]); receivedText=[[NSString alloc] initWithData:receivedData encoding: NSASCIIStringEncoding]; NSLog(@"receivedText=%@",receivedText); So I'm a bit stumped with the following questions: Where should I declare receivedData? My controller class? A third class? Can I just declare it like any normal NSMutableData variable? How do I give my URLDelegate class "access" to this variable? E.g., if I declare receivedData in my AppController class, wouldn't I have to instantiate AppController within URLDelegate? But how would this possible if it's the AppController class which is instantiating the URLDelegate class in the first place? Especially with regard to the last question, I feel like I must be overlooking something blindingly obvious and fundamental. If anyone could point me in the right direction, I would really appreciate it. Thank you!

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