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  • Generic that takes only numeric types (int double etc)?

    - by brandon
    In a program I'm working on, I need to write a function to take any numeric type (int, short, long etc) and shove it in to a byte array at a specific offset. There exists a Bitconverter.GetBytes() method that takes the numeric type and returns it as a byte array, and this method only takes numeric types. So far I have: private void AddToByteArray<T>(byte[] destination, int offset, T toAdd) where T : struct { Buffer.BlockCopy(BitConverter.GetBytes(toAdd), 0, destination, offset, sizeof(toAdd)); } So basically my goal is that, for example, a call to AddToByteArray(array, 3, (short)10) would take 10 and store it in the 4th slot of array. The explicit cast exists because I know exactly how many bytes I want it to take up. There are cases where I would want a number that is small enough to be a short to really take up 4 bytes. On the flip side, there are times when I want an int to be crunched down to just a single byte. I'm doing this to create a custom network packet, if that makes any ideas pop in to your heads. If the where clause of a generic supported something like "where T : int || long || etc" I would be ok. (And no need to explain why they don't support that, the reason is fairly obvious) Any help would be greatly appreciated! Edit: I realize that I could just do a bunch of overloads, one for each type I want to support... but I'm asking this question because I want to avoid precisely that :)

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  • How does SVN store commit time

    - by Salman
    I am working on a project that involves extracting details from a SVN server using SVNKit. My project is already complete and has been working we for a while now. During the testing, I noticed something rather very strange. the Commit Times my extract data seems is alway different from whats there in SVN Logs. I couldnt find any code in my project that could be inducing this difference but now I am looking as to how SVN server stores the Commit time in itself. As we have developer working from different part of the world thus resulting in different timezones, I was thinking that SVN might be storing time after converting them to GMT or timezone of the system on which SVN server is running. But that does not seem to be happening. Instead the times are stored as per the time when the commit was done and in that local timezone itself. I have been unable to find any substantial document on internet to support my theory so far. Can anybody in brief explain as how SVN store the Commit Time for each change? Documentaion links referring to this will be of great help.

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  • How to catch unintentional function interpositioning?

    - by SiegeX
    Reading through my book Expert C Programming, I came across the chapter on function interpositioning and how it can lead to some serious hard to find bugs if done unintentionally. The example given in the book is the following: my_source.c mktemp() { ... } main() { mktemp(); getwd(); } libc mktemp(){ ... } getwd(){ ...; mktemp(); ... } According to the book, what happens in main() is that mktemp() (a standard C library function) is interposed by the implementation in my_source.c. Although having main() call my implementation of mktemp() is intended behavior, having getwd() (another C library function) also call my implementation of mktemp() is not. Apparently, this example was a real life bug that existed in SunOS 4.0.3's version of lpr. The book goes on to explain the fix was to add the keyword static to the definition of mktemp() in my_source.c; although changing the name altogether should have fixed this problem as well. This chapter leaves me with some unresolved questions that I hope you guys could answer: Does GCC have a way to warn about function interposition? We certainly don't ever intend on this happening and I'd like to know about it if it does. Should our software group adopt the practice of putting the keyword static in front of all functions that we don't want to be exposed? Can interposition happen with functions introduced by static libraries? Thanks for the help. EDIT I should note that my question is not just aimed at interposing over standard C library functions, but also functions contained in other libraries, perhaps 3rd party, perhaps ones created in-house. Essentially, I want to catch any instance of interpositioning regardless of where the interposed function resides.

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  • C++ STL Map vs Vector speed

    - by sub
    In the interpreter for my experimental programming language I have a symbol table. Each symbol consists of a name and a value (the value can be e.g.: of type string, int, function, etc.). At first I represented the table with a vector and iterated through the symbols checking if the given symbol name fitted. Then I though using a map, in my case map<string,symbol>, would be better than iterating through the vector all the time but: It's a bit hard to explain this part but I'll try. If a variable is retrieved the first time in a program in my language, of course its position in the symbol table has to be found (using vector now). If I would iterate through the vector every time the line gets executed (think of a loop), it would be terribly slow (as it currently is, nearly as slow as microsoft's batch). So I could use a map to retrieve the variable: SymbolTable[ myVar.Name ] But think of the following: If the variable, still using vector, is found the first time, I can store its exact integer position in the vector with it. That means: The next time it is needed, my interpreter knows that it has been "cached" and doesn't search the symbol table for it but does something like SymbolTable.at( myVar.CachedPosition ). Now my (rather hard?) question: Should I use a vector for the symbol table together with caching the position of the variable in the vector? Should I rather use a map? Why? How fast is the [] operator? Should I use something completely different?

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  • jquery dialog is clearing my form fields and I need to return a value from a jquery dialog

    - by Seth
    1.) I have a jQuery dialog that is opened whenever a particular textbox is focused. The dialog's contents are loaded from ajax and the unique ID of the textbox that was focused is passed in the ajax call (like this): $('[name=start_airport[]],[name=finish_airport[]]').click(function(){   var id = $(this).attr('id');   if($('#use_advanced_airport_selector').attr('checked')) {     $('#advanced_airport_selector').dialog({       open : function() {         $(this).load('/flight-booker/advanced-airport-selector.php?callerID='+id);       }     });     $('#advanced_airport_selector').dialog('open');   } }); (where advanced_airport_selector is an empty div) THAT PART WORKS FINE. However, when I make my ajax call within my dialog, all my form values are reset! No matter what I do, when that dialog opens, all form values are reset (not just the value of the textbox that was focused). I simply don't understand what would cause this behavior! But that's only issue #1. 2.) I need to be able to return a value from that dialog box. I am passing the ID in the ajax query so that I can use a jquery selector to update the caller's value after certain actions are performed within the dialog box. However, I can't actually access that textbox because of DOM_ERRORS that I've never come across. It doesn't make any sense! There's way to much code to post, and it's really hard to explain, so sorry if I'm unclear as to what I'm asking.

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  • Using static variables for Strings

    - by Vivart
    below content is taken from Best practice: Writing efficient code but i didn't understand why private static String x = "example"; faster than private static final String x ="example"; Can anybody explain this. Using static variables for Strings When you define static fields (also called class fields) of type String, you can increase application speed by using static variables (not final) instead of constants (final). The opposite is true for primitive data types, such as int. For example, you might create a String object as follows: private static final String x = "example"; For this static constant (denoted by the final keyword), each time that you use the constant, a temporary String instance is created. The compiler eliminates "x" and replaces it with the string "example" in the bytecode, so that the BlackBerry® Java® Virtual Machine performs a hash table lookup each time that you reference "x". In contrast, for a static variable (no final keyword), the String is created once. The BlackBerry JVM performs the hash table lookup only when it initializes "x", so access is faster. private static String x = "example"; You can use public constants (that is, final fields), but you must mark variables as private.

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  • emacs: How to intelligently handle buffer-modified when setting text properties?

    - by Cheeso
    The documentation on Text Properties says: Since text properties are considered part of the contents of the buffer (or string), and can affect how a buffer looks on the screen, any change in buffer text properties marks the buffer as modified. First, I don't understand that policy. Can anyone explain? The text props are not actually saved in the file, when the buffer is saved. So why mark the buffer as modified? For me, buffer-modified indicates "some changes have not yet been saved." but understanding the policy is just for my own amusement. More importantly, is there an already-established way that, in code, I can change syntax text properties on the text in a buffer, while keeping the buffer-modified flag set to whatever it was, prior to those changes? I'm thinking of something like save-excursion. It would be pretty easy to write, but this seems like a common case and I'd like to use the standard function, if possible. For more on the scenario - I have a mode that does a full text scan and sets syntax-tabe properties on the text. After opening a buffer, the scan runs, but it results in a buffer with buffer-modified set to t . As always, thanks.

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  • The program fails to display `cout` when it is run

    - by Jeff - FL
    Hello, I justed started a C++ course & I wrote, compiled, debugged & ran my first program: // This program calculates how much a little league team spent last year to purchase new baseballs. #include <iostream> using namespace std; int baseballs; int cost; int total; int main() { baseballs, cost, total; // Get the number of baseballs were purchased. cout << "How many baseballs were purchased? "; cin >> baseballs; // Get the cost of baseballs purchased. cout << "What was the cost of each baseball purchased? "; cin >> cost; // Calculate the total. total = baseballs * cost; // Display the total. cout << "The total amount spent $" << total << endl; return 0; } The only probelm that I encountered was that when I ran the program it failed to display the total amount spent (cout). Could someone please explain why? Thanks Jeff H - Sarasota, FL

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  • JQuery DataTables link item

    - by rogcg
    I'm trying to link the items from a specific column, but each one will be linked for a different id from the json string. Unfortunately I can't find a way to do this using the API (I know there is a lot of ways to do that without using the API ), but I'm looking for a way to link a item from a column (each one with a link for a specific id). So here is my code, I use getJSON to get the JSON from the server, and I load the data from this JSON to the table like this: $.getJSON("/method/from/server/", function(data) { var total = 0; $("#table_body").empty(); var oTable = $('#mytable').dataTable( { "sPaginationType" : "full_numbers", "aaSorting": [[ 0, "asc" ]] }); oTable.fnClearTable(); $.each(data, function(i, item) { oTable.fnAddData( [ item.contact_name, item.contact_email ] ); }); }); What I want to do, is for each row, link the contact_name to its id, which is also in the JSON, and can be accessed inside this $.each loop by using item.contact_id. Is there a way to do this using DataTables API, if yes, could you explain me and provide a good resource that will help me with this? Thanks.

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  • Why I'm not getting "Multiple definition" error from the g++?

    - by ban
    I tried to link my executable program with 2 static libraries using g++. The 2 static libraries have the same function name. I'm expecting a "multiple definition" linking error from the linker, but I did not received. Can anyone help to explain why is this so? staticLibA.h #ifndef _STATIC_LIBA_HEADER #define _STATIC_LIBA_HEADER int hello(void); #endif staticLibA.cpp #include "staticLibA.h" int hello(void) { printf("\nI'm in staticLibA\n"); return 0; } output: g++ -c -Wall -fPIC -m32 -o staticLibA.o staticLibA.cpp ar -cvq ../libstaticLibA.a staticLibA.o a - staticLibA.o staticLibB.h #ifndef _STATIC_LIBB_HEADER #define _STATIC_LIBB_HEADER int hello(void); #endif staticLibB.cpp #include "staticLibB.h" int hello(void) { printf("\nI'm in staticLibB\n"); return 0; } output: g++ -c -Wall -fPIC -m32 -o staticLibB.o staticLibB.cpp ar -cvq ../libstaticLibB.a staticLibB.o a - staticLibB.o main.cpp extern int hello(void); int main(void) { hello(); return 0; } output: g++ -c -o main.o main.cpp g++ -o multipleLibsTest main.o -L. -lstaticLibA -lstaticLibB -lstaticLibC -ldl -lpthread -lrt

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  • Android import project errors

    - by Jsmith102
    Hey everyone, I'm a beginner, so I'll try my best to explain this problem succinctly. Basically, a friend of mine and I were playing around with the Android SDK, editing a simple RSS reader. We could launch it in the emulator and even install it on our real devices. Fast forward a few days, I'm trying to import the exact same code that was working a few days earlier into Eclipse on my laptop. I tried both importing and new project from existing source. Both return these new errors that we never had originally. I got an error that involved the auto generated "R" file, but I have solved this. Now, I'm getting 3 errors that I have never had before - The method onClick(View) of type new View.OnClickListener(){} must override a superclass method - displayed twice ( 2 different lines) The method onTabChanged(String) of type new TabHost.OnTabChangeListener(){} must override a superclass method My question is this - What would cause the these discrepancies between importing/running on my friends computer and mine? Also, we are both using the latest version of Java/Eclipse Thanks in advance for any insight.

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  • Console in VS 2012 Express for C++?

    - by Live2Code
    I'm very new to programming, so be nice. I was using Eclipse for C/C++ devs for a while, but it seemed quite buggy so I was advised to switch to Visual Studio Express. I'm just testing out with a simple "Hello World" program #include <iostream> #include <string> using namespace std; int main( int argc, char ** argv ) { string response; cout << "Gimme a string: " << flush; cin >> response; cout << "The string is: " << response << endl; system("pause"); return 0; } not much to go wrong there anyway, I noticed that there is no "console" like in Eclipse. All of the text pops up in a little command prompt window. And, also, this window closes right after displaying new text if there is no other things to do after it (like a cin). I have been told that I can use system("pause") but there has to be a better way. In Eclipse, the text would not suddenly disappear because the console window closed. i know this question might be a little confusing, comment and I'll try to explain what I'm saying. Or paste the codes into your Visual Studio 2012 Express Edition. But is there a way to display all of my text and whatever in a "console" as opposed to a command prompt-type window; and why does it always close before I can read the last thing?

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  • Bad idea to have the same object, have a different side effect after method call.

    - by Nathan W
    Hi all, I'm having a bit of a gesign issue(again). Say I have this Buttonpad object: now this object is a wrapper object over one in a com object. At the moment it has a method on it called CreateInto(IComObject). Now to make a new button pad in the Com Object. You do: ButtonPad pad = new ButtonPad(); pad.Title = "Hello"; // Set some more properties. pad.CreateInto(Cominstance); The createinfo method will excute the right commands to buid the button pad in the com object. After it has been created it any calls against it are foward to the underlying object for change so: pad.Title = "New title"; will call the com object to set the title and also set the internal title variable. Basically any calls before the CreateInfo method only affect the .NET object anything after has the side effect of calling the com object also. I'm not very good at sequence diagrams but here is my attempt to explain whats going on: This doesn't feel good to me, it feels like I'm lying to the user about what the button pad does. I was going to have a object called WrappedButtonPad, which is returned from CreateInto and the user could make calls against that to make changes to the Com Object, but I feel having two objects that almost do the same thing but only differ by names might be even worse. Are these valid designs, or am I right to be worried? How else would you handle a object the can create and query a com object?

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  • which one of these is an example of coercion

    - by user1890210
    I have been pondering a multiple choice question on coercion. One of the 4 examples a,b,c or d is an example of coercion. I narrowed it down to A or B. But I am having a problem choosing between the two. Cane someone please explain why one is coercion and one isn't. A) string s="tomat"; char c='o'; s=s+c; I thought A could be correct because we have two different types, character and string, being added. Meaning that c is promoted to string, hence coercion. B) double x=1.0; double y=2.0; int i=(int)(x+y); I also thought B was the correct answer because the double (x+y) is being turned into a int to be placed in i. But I thought this could be wrong because its being done actively through use of (int) rather than passively such as "int i = x + y" I'll list the other two options, even though I believe that neither one is the correct answer C) char A=0x20; A = A << 1 | 0x01; cout << A << endl; D) double x=1.0; double y=x+1; return 0; I'm not just looking for an answer, but an explanation. I have read tons of things on coercion and A and B both look like the right answer. So why is one correct and the other not.

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  • Can I create an application using SlimDX relying on the DirectX DLLs already bundled with Vista/Win7

    - by norheim.se
    I'm working on a .NET application that requires the use of accelerated graphics, currently DirectX 9.0c. The software is quite graphics intensive and must, in addition, be launchable from a CD or by ClickOnce without the user requiring administrator's permissions. I currently use SlimDX, which works great featurewise, but the users are getting rather annoyed by having to install the DirectX redistributable. Especially since this does require elevated permissions. It is rather hard to explain to them why the version of DirectX already bundled with their OS is not sufficient. After all - DirectX 9.0c has been around since 2004, and I'm not using any new fancy features. The ability to deliver an application that "just works" in Vista or Windows 7, without any particular additional prerequisites would be a huge advantage. Therefore: Is there any way I can build an application using DirectX 9.0c based on SlimDX, that relies only on the libraries provided in the standard Windows Vista/Win7 installation? That is - without requiring the additional DirectX redistributable to be installed? If not - is there any other managed (and preferably not abandoned) DirectX wrapper that can serve this purpose? Thanks in advance!

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  • PHP preg_match: a pattern which satisfies all MySQL field names (including 'table.field' formations)

    - by gsquare567
    i need a pattern which satisfies mysql field names, but also with the option of having a table name before it examples: mytable.myfield myfield my4732894__7289FiEld here's what i tried: $pattern = "/^[a-zA-Z0-9_]*?[\.[a-zA-Z0-9_]]?$/"; this worked for what i needed before, which was just the field name: $pattern = "/^[a-zA-Z0-9_]*$/"; any ideas why my addition isnt working? maybe i'm making up regex, so i'll explain what i added... the first '?' is to say that it isn't greedy, ie. it will stop if the next part, namely "[.[a-zA-Z0-9_]]?" is satisfied. now, that second part is just the same as the first except it is optional (hence the '?' at the end) and it starts with a period (hence the '[.' and ']' wrapping my old clause. and obviously, the "^" and "$" rep the beginning and end of the string so... any ideas? (also, i'm a tad confused as to why i need to put in those "/"s in the begining/end anyways, so if you could tell me why it's required, that'd be awesome) thanks a lot! (and thanks for reading this all if you actually did... it's quite a ramble)

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  • Two entities with @ManyToOne joins the same table

    - by Ivan Yatskevich
    I have the following entities Student @Entity public class Student implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; //getter and setter for id } Teacher @Entity public class Teacher implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; //getter and setter for id } Task @Entity public class Task implements Serializable { @Id @GeneratedValue(strategy = GenerationType.AUTO) private Long id; @ManyToOne(optional = false) @JoinTable(name = "student_task", inverseJoinColumns = { @JoinColumn(name = "student_id") }) private Student author; @ManyToOne(optional = false) @JoinTable(name = "student_task", inverseJoinColumns = { @JoinColumn(name = "teacher_id") }) private Teacher curator; //getters and setters } Consider that author and curator are already stored in DB and both are in the attached state. I'm trying to persist my Task: Task task = new Task(); task.setAuthor(author); task.setCurator(curator); entityManager.persist(task); Hibernate executes the following SQL: insert into student_task (teacher_id, id) values (?, ?) which, of course, leads to null value in column "student_id" violates not-null constraint Can anyone explain this issue and possible ways to resolve it?

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  • Can someone recommend a good tutorial on MySQL indexes, specifically when used in an order by clause

    - by Philip Brocoum
    I could try to post and explain the exact query I'm trying to run, but I'm going by the old adage of, "give a man a fish and he'll eat for a day, teach a man to fish and he'll eat for the rest of his life." SQL optimization seems to be very query-specific, and even if you could solve this one particular query for me, I'm going to have to write many more queries in the future, and I'd like to be educated on how indexes work in general. Still, here's a quick description of my current problem. I have a query that joins three tables and runs in 0.2 seconds flat. Awesome. I add an "order by" clause and it runs in 4 minutes and 30 seconds. Sucky. I denormalize one table so there is one fewer join, add indexes everywhere, and now the query runs in... 20 minutes. What the hell? Finally, I don't use a join at all, but rather a subquery with "where id in (...) order by" and now it runs in 1.5 seconds. Pretty decent. What in God's name is going on? I feel like if I actually understood what indexes were doing I could write some really good SQL. Anybody know some good tutorials? Thanks!

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  • Should a C++ constructor do real work?

    - by Wade Williams
    I'm strugging with some advice I have in the back of my mind but for which I can't remember the reasoning. I seem to remember at some point reading some advice (can't remember the source) that C++ constructors should not do real work. Rather, they should initialize variables only. The advice when on to explain that real work should be done in some sort of init() method, to be called separately after the instance was created. The situation is I have a class that represents a hardware device. It makes logical sense to me for the constructor to call the routines that query the device in order to build up the instance variables that describe the device. In other words, once new instantiates the object, the developer receives an object which is ready to be used, no separate call to object-init() required. Is there a good reason why constructors shouldn't do real work? Obviously it could slow allocation time, but that wouldn't be any different if calling a separate method immediately after allocation. Just trying to figure out what gotchas I not currently considering that might have lead to such advice.

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  • IE8: weird border around HTML button element

    - by s427
    I have a button element with a custom background (image+color) and no borders except for a 2px border-bottom (and a bunch of other properties --code below) which renders quite differently in Firefox and in IE8. The problem is, this is a work for a company that uses IE8 as their only browser, so it's important that the button renders well in IE8. Here's a visual comparison between the two: My question here is not about the padding difference (I'm looking into that), but about the weird border that is visible on IE8 in addition to the regular border (border-bottom). Can anyone explain to me where it comes from and how to get rid of it? Thanks in advance. Here is the HTML code: <button class="btn" id="c_edit"> <span>Annuler</span> </button> And here is the CSS: .btn { display: inline-block; margin: 0 0 7px 5px; padding: 0; color: #ddd; font-size: 14px; font-family: FrutigerLTStd55Roman, sans-serif; text-decoration: none; border: none; border-bottom: 2px solid #222; background-color: #999; background-image: url('img/btn_bg.gif'); background-position: 0 bottom; background-repeat: repeat-x; cursor: pointer; transition: all .5s ease-out; } .btn span { display: inline-block; margin: 0; padding: 8px 10px 6px 40px; background-color: transparent; background-position: 4px 0; background-repeat: no-repeat; }

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  • Why do the usable sizes differ

    - by Raigex
    Again, dont really know how to phrase the question so I will explain. I have a video recorder application. I open my camera with cameraRecorder = Camera.open(1); //(this is the front facing camera) And get the camera parameters and all supported preview sizes CameraParameters tmpParams = cameraRecorder.getParameters(); List<Camera.Size> tmpList = tmpParams.getSupportedPreviewSizes(); one of the preview sizes on the Galaxy Tab 10.1 running ICS (4.0.4) is 800x600 but when I try to set the Video size in my media Player mediaRecorder.setVideoSize(800,600); I get this error: 12-19 17:27:55.035: E/CameraSource(110): Video dimension (800x600) is unsupported 12-19 17:27:55.035: E/StagefrightRecorder(110): cameraSource do not init 12-19 17:27:55.035: E/StagefrightRecorder(110): setupCameraSource failed. (-19) 12-19 17:27:55.035: E/StagefrightRecorder(110): setupMediaSource is failed. (-19) 12-19 17:27:55.035: E/StagefrightRecorder(110): setupMPEG4Recording is failed. (-19) 12-19 17:27:55.035: E/MediaRecorder(30119): start failed: -19 Does anyone know why this discrepancy might exist (I know one of the supported record sizes is 1280x720 but that is too big for me).

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  • Perform function in attr() callback?

    - by Jared
    Hello, Not sure if I am doing this correctly or not. Here is my JS: var currentIMG; $( '.leftMenuProductButton' ).hover ( function () { currentIMG = $("#swapImg").attr("src"); var swapIMG = $(this).next(".menuPopup").attr("id"); $("#swapImg").css("opacity", 0).attr("src", productImages[swapIMG], function(){ $("#swapImg").fadeTo("slow", 1); }); }, function () { $("#swapImg").stop().attr("src",currentIMG); }); What I am trying to do is Set a IMG Opacity to 0 (#swapImg), replace it's SRC, then fade it back in. So I am trying to fade it back in using a callback from the attr(). If I am doing this incorrectly, can someone please explain a better way to do this? The reason I am trying to do it in the callback is that I need the fadeTo to only occur after the new image is fully loaded, otherwise it does a bit of a flash. I am using jquery 1.4, and according to http://jquery14.com/day-01/jquery-14 it appears you can do a callback in the attr() method.

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  • What's the correct way to pass parameters from VBScript to COM interface implemented in C#?

    - by nopopem
    I'm trying to expose a fairly simple C# class to COM which should be usable from VBScript (among others). Some objects need to be created via COM calls and will be used in furter calls later on. The definition of the exposed classes and interfaces looks like this: namespace Test { [InterfaceType(ComInterfaceType.InterfaceIsIDispatch)] public interface IComInterface { IFoo CreateFoo(); void UseFoo(int x, IFoo f); } [ClassInterface(ClassInterfaceType.None)] public sealed class CComInterface : IComInterface { public CComInterface() {} public IFoo CreateFoo() { return new Foo(); } public void UseFoo(int x, IFoo f) { f.Bar(); } } [InterfaceType(ComInterfaceType.InterfaceIsIDispatch)] public interface IFoo { void Bar(); } [ClassInterface(ClassInterfaceType.None)] public class Foo : IFoo { internal Foo() {} public void Bar() {} } } The simplest thinkable COM client in VBScript does this: Dim ci Set ci = WScript.CreateObject("Test.CComInterface") Dim foo Set foo = ci.CreateFoo foo.Bar ci.UseFoo 0, foo While the call to Bar succeeds, calling UseFoo fails with "Error 5: invalid procedure call or invalid argument" The generated IDL seems ok to me: dispinterface IComInterface { properties: methods: [id(0x60020003)] IFoo* CreateFoo(); [id(0x60020004)] void UseFoo( [in] long x, [in] IFoo* f); }; The vbs call succeeds when I wrap the second parameter in parentheses like this: ci.UseFoo 0, (foo) As far as I understand (I'm no VBScript expert however) this forces the reference to foo to be passed by value, i.e. a copy of the reference is being made. How can I change the interface so that it can be called with the foo reference directly? Since this will be a public interface used by customers I don't like the idea of having to explain why all the objects created need to be passed back in an extra pair of parentheses...

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  • Prototyping Qt/C++ in Python

    - by tstenner
    I want to write a C++ application with Qt, but build a prototype first using Python and then gradually replace the Python code with C++. Is this the right approach, and what tools (bindings, binding generators, IDE) should I use? Ideally, everything should be available in the Ubuntu repositories so I wouldn't have to worry about incompatible or old versions and have everything set up with a simple aptitude install. Is there any comprehensive documentation about this process or do I have to learn every single component, and if yes, which ones? Right now I have multiple choices to make: Qt Creator, because of the nice auto completion and Qt integration. Eclipse, as it offers support for both C++ and Python. Eric (haven't used it yet) Vim PySide as it's working with CMake and Boost.Python, so theoretically it will make replacing python code easier. PyQt as it's more widely used (more support) and is available as a Debian package. Edit: As I will have to deploy the program to various computers, the C++-solution would require 1-5 files (the program and some library files if I'm linking it statically), using Python I'd have to build PyQt/PySide/SIP/whatever on every platform and explain how to install Python and everything else.

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  • Batch insert mode with hibernate and oracle: seems to be dropping back to slow mode silently

    - by Chris
    I'm trying to get a batch insert working with Hibernate into Oracle, according to what i've read here: http://docs.jboss.org/hibernate/core/3.3/reference/en/html/batch.html , but with my benchmarking it doesn't seem any faster than before. Can anyone suggest a way to prove whether hibernate is using batch mode or not? I hear that there are numerous reasons why it may silently drop into normal mode (eg associations and generated ids) so is there some way to find out why it has gone non-batch? My hibernate.cfg.xml contains this line which i believe is all i need to enable batch mode: <property name="jdbc.batch_size">50</property> My insert code looks like this: List<LogEntry> entries = ..a list of 100 LogEntry data classes... Session sess = sessionFactory.getCurrentSession(); for(LogEntry e : entries) { sess.save(e); } sess.flush(); sess.clear(); My 'logentry' class has no associations, the only interesting field is the id: @Entity @Table(name="log_entries") public class LogEntry { @Id @GeneratedValue public Long id; ..other fields - strings and ints... However, since it is oracle, i believe the @GeneratedValue will use the sequence generator. And i believe that only the 'identity' generator will stop bulk inserts. So if anyone can explain why it isn't running in batch mode, or how i can find out for sure if it is or isn't in batch mode, or find out why hibernate is silently dropping back to slow mode, i'd be most grateful. Thanks

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