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  • javascript prototype problem

    - by Chris Tosswill
    So I have a rather basic javascript problem which I have been slamming my head into a wall over for awhile: <div class='alist'> <ul> <li class='group_1'> An Item </li> <li class='group_1'> An Item </li> <li class='group_2'> An Item </li> </ul> </div> <div class='alist'> <ul> <li class='group_1'> An Item </li> <li class='group_1'> An Item </li> <li class='group_2'> An Item </li> </ul> </div> <script> function toggle_item( num ){ $$( 'li.group_' + num ).invoke('toggle'); } </script> Basically, I need to create a sweeper that sets the div to display:none if all the li are display:none. I think it would start like: function sweep(){ $$('div.alist').each( function( s ) { ar = s.down().children }); } Any suggestions for good tutorials would be welcome as well

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  • When calling a static method on parent class, can the parent class deduce the type on the child (C#)

    - by Matt
    Suppose we have 2 classes, Child, and the class from which it inherits, Parent. class Parent { public static void MyFunction(){} } class Child : Parent { } Is it possible to determine in the parent class how the method was called? Because we can call it two ways: Parent.MyFunction(); Child.MyFunction(); My current approach was trying to use: MethodInfo.GetCurrentMethod().ReflectedType; // and MethodInfo.GetCurrentMethod().DeclaringType; But both appear to return the Parent type. If you are wondering what, exactly I am trying to accomplish (and why I am violating the basic OOP rule that the parent shouldn't have to know anything about the child), the short of it is this (let me know if you want the long version): I have a Model structure representing some of our data that persists to the database. All of these models inherit from an abstract Parent. This parent implements a couple of events, such as SaveEvent, DeleteEvent, etc. We want to be able to subscribe to events specific to the type. So, even though the event is in the parent, I want to be able to do: Child.SaveEvent += new EventHandler((sender, args) => {}); I have everything in place, where the event is actually backed by a dictionary of event handlers, hashed by type. The last thing I need to get working is correctly detecting the Child type, when doing Child.SaveEvent. I know I can implement the event in each child class (even forcing it through use of abstract), but it would be nice to keep it all in the parent, which is the class actually firing the events (since it implements the common save/delete/change functionality).

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  • error in a c code while trying to remove whitespace

    - by mekasperasky
    this code is the base of lexer , and it does the basic operation of removing the whitespaces from a source file and rewrites it into another file with each word in separate lines . But i am not able to understand why the file lext.txt not getting updated? #include<stdio.h> /* this is a lexer which recognizes constants , variables ,symbols, identifiers , functions , comments and also header files . It stores the lexemes in 3 different files . One file contains all the headers and the comments . Another file will contain all the variables , another will contain all the symbols. */ int main() { int i; char a,b[20],c; FILE *fp1,*fp2; fp1=fopen("source.txt","r"); //the source file is opened in read only mode which will passed through the lexer fp2=fopen("lext.txt","w"); //now lets remove all the white spaces and store the rest of the words in a file if(fp1==NULL) { perror("failed to open source.txt"); //return EXIT_FAILURE; } i=0; while(!feof(fp1)) { a=fgetc(fp1); if(a!="") { b[i]=a; printf("hello"); } else { b[i]='\0'; fprintf(fp2, "%.20s\n", b); i=0; continue; } i=i+1; /*Switch(a) { case EOF :return eof; case '+':sym=sym+1; case '-':sym=sym+1; case '*':sym=sym+1; case '/':sym=sym+1; case '%':sym=sym+1; case ' */ } return 0; }

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  • Is inheritance bad nowadays?

    - by mafutrct
    Personally, I think inheritance is a great tool, that, when applied reasonably, can greatly simplify code. However, I seems to me that many modern tools dislike inheritance. Let's take a simple example: Serialize a class to XML. As soon as inheritance is involved, this can easily turn into a mess. Especially if you're trying to serialize a derived class using the base class serializer. Sure, we can work around that. Something like a KnownType attribute and stuff. Besides being an itch in your code that you have to remember to update every time you add a derived class, that fails, too, if you receive a class from outside your scope that was not known at compile time. (Okay, in some cases you can still work around that, for instance using the NetDataContract serializer in .NET. Surely a certain advancement.) In any case, the basic principle still exists: Serialization and inheritance don't mix well. Considering the huge list of programming strategies that became possible and even common in the past decade, I feel tempted to say that inheritance should be avoided in areas that relate to serialization (in particular remoting and databases). Does that make sense? Or am messing things up? How do you handle inheritance and serialization?

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  • What is the best way to properly test object equality against an array of objects?

    - by radesix
    My objective is to abort the NSXMLParser when I parse an item that already exists in cache. The basic flow of the program works like this: 1) Program starts and downloads an XML feed. Each item in the feed is represented by a custom object (FeedItem). Each FeedItem gets added to an array. 2) When the parsing is complete the contents of the array (all FeedItem objects) are archived to the disk. The next time the program is executed or the feed is refreshed by the user I begin parsing again; however, since a cache (array) now exists as each item is parsed I want to see if the object exists in the cache. If it does then I know I have downloaded all the new items and no longer need to continue parsing. What I am learning, I think, is that I can't use indexOfObject or indexOfObjectIDenticalTo: because these really seem to be checking to see that the objects are using the same memory address (thus identical). What I want to do is see if the contents of the object are equal (or at least some of the contents). I've done some research and found that I can override the IsEqual method; however, I really don't want to iterate/enumerate through the entire cache contents table for every newly parsed XML FeedItem. Is iterating through the collection and testing each one for equality the only way to do this or is there a better technique I am not aware of? Currently I am using the following code though I know it needs to change: NSUInteger index = [self.feedListCache.feedList indexOfObject:self.currentFeedItem]; if (index == NSNotFound) { }

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  • Testing variable types in Python

    - by Jasper
    Hello, I'm creating an initialising function for the class 'Room', and found that the program wouldn't accept the tests I was doing on the input variables. Why is this? def __init__(self, code, name, type, size, description, objects, exits): self.code = code self.name = name self.type = type self.size = size self.description = description self.objects = objects self.exits = exits #Check for input errors: if type(self.code) != type(str()): print 'Error found in module rooms.py!' print 'Error number: 110' elif type(self.name) != type(str()): print 'Error found in module rooms.py!' print 'Error number: 111' elif type(self.type) != type(str()): print 'Error found in module rooms.py!' print 'Error number: 112' elif type(self.size) != type(int()): print 'Error found in module rooms.py!' print 'Error number: 113' elif type(self.description) != type(str()): print 'Error found in module rooms.py!' print 'Error number: 114' elif type(self.objects) != type(list()): print 'Error found in module rooms.py!' print 'Error number: 115' elif type(self.exits) != type(tuple()): print 'Error found in module rooms.py!' print 'Error number: 116' When I run this I get this error: Traceback (most recent call last): File "/Users/Jasper/Development/Programming/MyProjects/Game Making Challenge/Europa I/rooms.py", line 148, in <module> myRoom = Room(101, 'myRoom', 'Basic Room', 5, '<insert description>', myObjects, myExits) File "/Users/Jasper/Development/Programming/MyProjects/Game Making Challenge/Europa I/rooms.py", line 29, in __init__ if type(self.code) != type(str()): TypeError: 'str' object is not callable

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  • PDF reviewer in C# (ASP.NET/Silverlight?)

    - by Anders Holmström
    Hi. I'm essentially planning to mimic the comment functions on PDF files, but online. That is; a user should be able to log in and upload a PDF file, and then numerous different users should be able to add comments etc to this same file (and view the file, with comments, online). External libraries are ok. Free obviously preferred, but commercial ones are fine if they provide a lot of the needed functionality. Note that this is meant to be used in a commercial environment. Comments don't necessarily need to be able to be exported from the site. I.e. if the comments are just put as a layer on top of a PDF file (and not in the actual file) that's ok. But obviously the more export functionality the better. I have looked at a few libraries (using the related questions and google) and while I find some that seem to do sort of what I want I'm not sure they are the bee's knees plus I would like to do as much myself as possible. The three basic approaches I've thought of is: Use some sort of native PDF viewing and then just smack down a layer on top of it where you can move around comments etc. Convert PDFs to HTML and work from there. Problem here it would either require proper PDFs (e.g. non-scanned) or really good OCR which seems a bit tedious. Convert PDFs to images and work from there. I'm afraid this will create massive images however. We're talking PDFs that can be hundreds of pages. One option would of course to just display one PDF page (image) at a time. And last - should I look at Silverlight for this or go with ASP.NET? Ideas and input concerning this project are much appreciated.

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  • Senior programming 'guru' who can't program - should I find a different career?

    - by confess
    Background: According to my resume I'm supposed to be pretty good at programming. I've worked on a ton of big projects at big companies over many years. When I go for an interview and someone looks at my resume they immediately assume I really know what I'm talking about. I generally communicate well, present myself well, know the 'jargon' and know a lot about technology at a high level, which makes matters worse because after talking to me for a while an interviewer really believes that what my resume says is probably true. The Problem: The problem arises when someone asks me to code something. I choke. As a programmer I have almost no capacity to come up with creative solutions of my own. I can't think through solutions to a programming problem the way good programmers are usually able to. I read questions on StackOverflow and the answer is obvious to me after I read other people's answers but if I am the first person to look at a question with no hints from anyone else I usually don't know where to start. At work it's the same thing. I'm fine if I'm correcting other people's code. I can identify the source of a bug quicker than anyone I work with. But if you ask me to sit down and code up a new application from scratch I will spend ten times longer than programmers who are much more junior than me. Question: Now that I am looking for work this is raising its ugly head in interview situations and making me feel desperately that I'm in the wrong career. I don't know if this problem is incompetence, laziness or some combination of these. Does anyone have any ideas about what I might be dealing with - are there books or exercises that could help me with this basic problem?

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  • OOP + MVC advice on Member Controller

    - by dan727
    Hi, I am trying to follow good practices as much as possible while I'm learning using OOP in an MVC structure, so i'm turning to you guys for a bit of advice on something which is bothering me a little here. I am writing a site where I will have a number of different forms for members to fill in (mainly data about themselves), so i've decided to set up a Member controller where all of the forms relating to the member are represented as individual methods. This includes login/logout methods, as well as editing profile data etc. In addition to these methods, i also have a method to generate the member's control panel widget, which is a constant on every page on the site while the member is logged in. The only thing is, all of the other methods in this controller all have the same dependencies and form templates, so it would be great to generate all this in the constructor, but as the control_panel method does not have the same dependencies etc, I cannot use the constructor for this purpose, and instead I have to redeclare the dependencies and same template snippets in each method. This obviously isn't ideal and doesn't follow DRY principle, but I'm wondering what I should do with the control_panel method, as it is related to the member and that's why I put it in that controller in the first place. Am I just over-complicating things here and does it make sense to just move the control_panel method into a simple helper class? Here are the basic methods of the controller: class Member_Controller extends Website_Controller { public function __construct() { parent::__construct(); if (request::is_ajax()) { $this->auto_render = FALSE; // disable auto render } } public static function control_panel() { //load control panel view $panel = new View('user/control_panel'); return $panel; } public function login() { } public function register() { } public function profile() { } public function household() { } public function edit_profile() { } public function logout() { } }

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  • PHP Error Form - Leave Contents of Form on Redirect

    - by user1371500
    I have a simple login form in which if an error occurs such as wrong password, I need it to be able to remember the username which was entered. Would I Go about doing this PHP or Javascript as I am not allowed to use JQuery. My current PHP - (Not Including the HTML Form) <?php //MySQl Connection mysql_connect("localhost", "root", "") or die(mysql_error()); mysql_select_db("clubresults") or die(mysql_error()); //Initiates New Session - Cookie session_start(); // Start a new session // Get the data passed from the form $username = $_POST['username']; $password = md5($_POST['pass']); // Do some basic sanitizing $username = mysql_real_escape_string($username); $password = mysql_real_escape_string($password); //Performs SQL Query to retrieve Login Details from DB $sql = "select * from admin_passwords where username = '$username' and password = '$password'"; $result = mysql_query($sql) or die ( mysql_error() ); //Assigns a Variable Count to 0 $count = 0; //Exectues a loop to increment on Successful Login while ($line = mysql_fetch_assoc($result)) { $count++; } //If count is equal to 1 Redirect user to the Members Page and Set Cookie if ($count == 1) { $_SESSION['loggedIn'] = "true"; header("Location: members.php"); // This is wherever you want to redirect the user to } else { //Else Echo that login was a failure. die('Login Failed. <a href=login.php>Click Here to Try Again</a>'); } ?> Any help would be appreciated. Cheers

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  • Rails - Beginner wants feedback on how they've modeled their app and how to do it better.

    - by adam
    I think the way I've modelled my app is a bit fishy and i need to rejig things, im just not sure how. I've already re-jigged and refactored before. It took a long time ( I'm a beginner ) and I'm hesitant to it again in case i head off in the wrong direction again. Basic Idea, user can submit an answer, another user can mark it correct or incorrect. If incorrect they have to write the correct answer. Users can view their and everybody else's correct and incorrect answers. So I did it this way class Answer has_one: correction end class Correction belongs_to :answer end when a user marks an answer as correct, I set checked_at:DateTime and checked_by_id:integer on the Answer object to keep track of who checked the answer and when. For incorrect answers I create a correction object which holds the correct answer and again checked_by and checked_at details. I don't like this because I have checked_by and checked_at in both models. It just doesn't sit right. Possible solutions are: Create a third model such as VerifiedAnswer and move the checked_by/at attributes to that. It will handle the situtation where an answer is marked correct. Or are these models thin enough (they dont have any other attributes) that I can just have one model ( Answer ) that has all the attributes to store all this information?

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  • Processing a resultset to look up foriegn keys (and poulate a new table!)

    - by Gilly
    Hi, I've been handed a dataset that has some fairly basic table structures with no keys at all. eg {myRubishTable} - Area(varchar),AuthorityName(varchar),StartYear(varchar),StartMonth(varcha),EndYear(varchar),EndMonth(varchar),Amount(Money) there are other tables that use the Area and AuthorityName columns as well as a general use of Month and Years so I I figured a good first step was to pull Area and Authority into their own tables. I now want to process the data in the original table and lookup the key value to put into my new table with foreign keys which looks like this. (lookup Tables) {Area} - id (int, PK), name (varchar(50)) {AuthorityName} - id(int, PK), name(varchar(50) (TargetTable) {myBetterTable} - id (int,PK), area_id(int FK-Area),authority_name_id(int FK-AuthorityName),StartYear (varchar),StartMonth(varchar),EndYear(varchar),EndMonth(varchar),Amount(money) so row one in the old table read MYAREA, MYAUTHORITY,2009,Jan,2010,Feb,10000 and I want to populate the new table with 1,1,1,2009,Jan,2010,Feb,10000 where the first '1' is the primary key and the second two '1's are the ids in the lookup tables. Can anyone point me to the most efficient way of achieving this using just SQL? Thanks in advance Footnote:- I've achieved what I needed with some pretty simple WHERE clauses (I had left a rogue tablename in the FROM which was throwing me :o( ) but would be interested to know if this is the most efficient. ie SELECT [area].[area_id], [authority].[authority_name_id], [myRubishTable].[StartYear], [myRubishTable].[StartMonth], [myRubishTable].[EndYear], [myRubishTable].[EndMonth], [myRubishTable].[Amount] FROM [myRubishTable],[Area],[AuthorityName] WHERE [myRubishTable].[Area]=[Area].[name] AND [myRubishTable].[Authority Name]=[dim_AuthorityName].[name] TIA

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  • Best way to do client/server validation in ASP.NET in 2010?

    - by punkouter
    First there was the ASP.NET validators and we used them... Then some people on the team did things manually in javascript... Then a bunch of jquery validation libraries came out... Then MVC2 came out with attributes as validators.. I work with apps that have alot of forms with alot of various validation (Some fields needs to be compared with other values in a DB so a postball/ajax call is required) .. Right now I have a mess of ASP.NET custom validators and functions that calculate on the server side as well. Can I get some opinions on the best tool/combination to approach this job that can create the smallest/most elegant code? Pure server side solution? AJAX/Jquery? A certain plugin for jquery? For example, I have 2 dates.. I want to make sure that the 1st date is less than the 2nd date... Are there jquery validators that encapsulate this? My feeling is if I can get jquery plugins to handle half the more basic validation for my that could cut my code in half.

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  • Trying to instantiate a class member in C++ with a variable name

    - by MarcZero
    Hello. I am writing a program for class that is asking us to create a class of "book". We are then supposed to create new instantiations of that class upon demand from the user. I am new to C++ so I am attempting to code this out but am running into a problem. The main problem is how do I instantiate a class with a variable if I don't know how many I will have to do ahead of time. The user could ask to add 1 book or 1000. I am looking at this basic code: This is the simple code I started with. I wanted to have an index int keep a number and have the book class I create be called by that int (0, 1, 2, etc...) So I attempted to convert the incoming index int into a string, but I'm kind of stuck from here. void addBook(int index){ string bookName; std::stringstream ss; ss << index; book bookName; cout << "Enter the Books Title: "; cin >> bookName.title; } But obviously this doesn't work as "bookName" is a string to the computer and not the class member I tried to create. All of the tutorials I have seen online and in my text show the classes being instantiated with names in the code, but I just don't know how to make it variable so I can create any amount of "books" that the user might want. Any insight on this would be appreciated. Thank you for your time.

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  • C++ Instantiate class and add name to array/vector then cycle through update functions from the array

    - by SD42
    I have a bunch of classes in a basic (and badly coded!) game engine that are currently instantiated in the code and have to have their individual update functions called. What I want to do is be able to create an instance of a class, pass the name to an array, and then subsequently cycle through the array to call the update functions of each class. I'm unsure as to whether or not this is an impossible or spectacularly stupid way of trying to manage objects, so please tell me if it is. So currently I might have manually instantiated Enemy class a couple of times: Enemy enem1; Enemy enem2; I then have to update them manually in the game loop: enem1.update(); enem2.update(); What method should I use to be able to spawn and destroy instances of the enemy class during gametime? Is it possible to populate an array with instantiated names and then do something like (and i'm aware this doesn't work); array[x].update(); Then iterate through the names in the array? Anything that even points me in the right direction would be greatly appreciated!

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  • Wordpress and Dynamic Programming Php

    - by user1675146
    I have geography pages for two types of business listings. Each page goes from state, county, city, but I need to have the same geography shared between two types of business. My two business types are dentist and chiropractors. I am trying to have a permalink structure like this: enter code here xyz.com/dentist/alabama enter code here xyz.com/dentist/alabama/polk-county/ enter code here xyz.com/chiropractors/alabama/ enter code here xyz.com/chiropractors/alabama/polk-county/ I originally was going to load the geography as pages and subpages, but with that method I cannot get the permalink separated by the type chiropractor and dentist. So now I have created a custom post type one for chiropractor and one for dentist which give me the permalink xyz.com/dentist and xyz.com/chiropractor. My question is now how to handle my category geography page. I was wondering if in wordpress it is possible to create a shell page such as xyz.com/dentist/[state]/ and then through php dynamically build a page for each state? So where it shows [state] it will be replaced with the actual state such as alabama, california etc when that specific page is viewed. But the shell page is just 1 page in the database. If so could someone give me a basic explanation on how to instruct a programmer to do this? Thank you.

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  • when i set property(retain), one "self" = one "retain"?

    - by Walter
    although I'm about to finish my first app, I'm still confused about the very basic memory management..I've read through many posts here and apple document, but I'm still puzzled.. For example..I'm currently doing things like this to add a label programmatically: @property (retain, nonatomic) UILabel *showTime; @sythesize showTime; showTime = [[UILabel alloc] initWithFrame:CGRectMake(45, 4, 200, 36)]; [self.showTime setText:[NSString stringWithFormat:@"%d", time]]; [self.showTime setFont:[UIFont fontWithName:@"HelveticaRoundedLT-Bold" size:23]]; [self.showTime setTextColor:numColor]; self.showTime.backgroundColor = [UIColor clearColor]; [self addSubview:self.showTime]; [showTime release]; this is my current practice, for UILabel, UIButton, UIImageView, etc... [Alloc init] it without self., coz I know this will retain twice.. but after the allocation, I put back the "self." to set the attributes.. My gut feel tells me I am doing wrong, but it works superficially and I found no memory leak in analyze and instruments.. can anyone give my advice? when I use "self." to set text and set background color, does it retain one automatically? THX so much!

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  • How can I define an irregular area of the screen and find the closest point to the mouse in that area?

    - by JonathonG
    I'm looking for a method to define an area of the screen that the mouse cannot leave. I have been directed by rob mayoff, the answerer of this question, that I can use a Quartz Event Tap to detect mouse events. This puts me part of the way to the solution to THIS question. I need to define an irregular area of the screen, not just a rectangle, that the mouse cannot leave. I have been researching this and the only idea I can come up with is using a bitmap to define the irregular area, as it will be very oddly shaped. However, I am open to solutions other than using a bitmap. Since this must be done on a Mac, I've determined that I will have to use objective C / Cocoa . I need to know how to define the area and, equally importantly, how to find the closest point in the area to the mouse (so that I can move the mouse to it if the mouse tries to move outside of the area). This is similar to what the restricted area will look like: [edit:] Okay, I've come up with part of the answer to this. If I can do a basic (light-weight) point collision detection on the image mask, I can use a simple algorithm to detect the closest point to the mouse on the black area of the image. I could do this by calculating distance between a pre-defined point (P) inside the black area of the image and the target mouse position (T), taking the midpoint (M), then checking if the midpoint is inside or outside of the shape (black or white, respectively). If M is inside the shape, then move the P to M, otherwise move T to the M, continuously recalculate this until the distance between T and P is 1 pixel or less, then move the mouse to the final calculated position. All of that being said, I still need some way to test the position of the mouse against that same position on the bitmap (assume the bitmap is the same resolution as the monitor), and check if that point is black or white. All of this needs to be done in the background, without this application actually having focus, or the bitmap being visible... is this possible?

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  • How to stream authenticated content with MediaPlayer on Android

    - by 102790073222983779908
    I've seen quite a few posts askign this question on SO but there doesn't seem to be a definitive answer (or at least an answer I like!) I've got content protected behind basic auth (username/password) -- I can download it fine using the various HTTP download clases but for the life of me I can't sort out how to tell media player to stream it (and provide the authentication). I saw one post that suggested it wasn't possible since the MediaPlayer is all native code and doesn't things like the Authenticator. There are plenty of examples of how to first download to a cached copy and then play that back but....That sort of sucks (and the files maybe 100's of MB's). I saw at least one proposal to download it in smalish chunks and then start & stop the playback (redirecting to the new file) but that sort of sucks also since there would (I presume) be a stutter (I haven't tried it though) The best idea I have at this point is to start downloading to a cache file and then when it's 'full enough' start up playback while I continue to fill the file.... I hope that this works (but again, haven't tried it). Am I missing something obvious? It's so painful to have all the various pieces almost working and I sort of convinced myself that there had to be a way to natively stream protected content (or have it take a already established & qualified InputStream) but it appears no joy. BTW I'm a Mac/iPhone guy and a newb at Android so I'm still fighting a bit of Java learning.... Excuse me if I'm missing somthing obvious. -john

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  • C#: Hijacking a near relative call

    - by Lex
    Alright, I'm trying to write a vary basic modification to a program NOT written by me. I DO NOT have the source to it. I also do not care if this only works for a single version of the program, so hard coding offsets is feasible. Anyways, I've found the function and where it is called in the compiled program. .text:1901C88F loc_1901C88F: ; CODE XREF: ConnectionThread+1A2j .text:1901C88F ; DATA XREF: .text:off_1901CC64o .text:1901C88F 8B C8 mov ecx, eax ; jumptable 1901C862 case 11 .text:1901C891 8B C6 mov eax, esi .text:1901C893 E8 48 C5 FF FF call ChatEvent According to IDA the full function signature is: char *__usercall ChatEvent<eax>(char *Data<eax>, unsigned int Length<ecx>) I already have all I need to patch the program during runtime, and do whatever other manipulations I need. What I need, is to be able to write a function like so: bool ProcessChat(char *Data, unsigned int Length); char *__usercall HijackFunction(char *Data, unsigned int Length){ if (ProcessChat(Data, Length)) Call OriginalChatEvent(Data, Length); } Get the jist of what I am trying to do? With stdcall function it's easy just replace the 4 byte address with my own function's address. But this is a near relative call, which is.. more annoying. So, anyone have any idea?

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  • how to reverse an angle

    - by MissHalberd
    I am no mathematician, but I somehow got into game development as a hobby. Having never studied anything beyond basic math, I have a lot of trouble figuring out how to reverse the angle of something, facing to the opposite direction, among the X axis. One image says more than 1000 words though (specially uneducated words): http://img156.imageshack.us/i/wihwin.png/ I basically want to reverse the direction of cannon objects adhered to a robot. When the robot changes from facing right to facing left, I do (180 - angle) as everyone suggested me, but it reverses the angle...literally, making the cannons aim up when they are aiming down. So, I need to do something else, but it escapes my knowledge. Anyone would be so kind to help me with this? Oh, I use regular C by the way, in case there's something built-in specific to it. To put it in other words, I work in 2D, so I want an angle that is facing right to face left. 0 being "totally to the right", 180 "left", 90 "up" and 270 "down". I want something that is aiming with an angle of 91 to turn into 89 when reversed, literally. There's no Z axis present. EDIT: Thanks for the answers! Trying them out now. I'll post which one worked in a minute!

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  • Changing the value of a variable

    - by neirpycc
    I'm trying to build a simple scoring app but I'm running into a problem trying to keep it so I don't have to repeat a bunch of code to deal with each 'base' individually. The basic idea is that when I click a button the script will; 1) grab the ID of said button 2) split the ID into two parts - (a) the bases name and (b) the button type (plus/minus) 3) if it's plus - add to the bases score, if it's minus - subtract from the bases score 4) update the assigned div with the new value The part I'm stuck at is adding and subtracting. I can't seem to get this to work. Here is the code: $('.base button').click(function() { var b1Score = 0; var b2Score = 0; var b3Score = 0; var b4Score = 0; var b5Score = 0; var clickedButton = $(this).attr('id'); var buttonInfo = clickedButton.split('-'); var baseClicked = buttonInfo[0]; var baseDirection = buttonInfo[1]; var baseDiv = ('#' + baseClicked); console.log('You clicked ' + clickedButton + '.'); if (baseDirection.indexOf('plus') >= 0) { console.log('Increasing ' + baseClicked + '!'); ++; $(baseDiv).val(); } else { console.log('Decreasing ' + baseClicked + '!'); --; $(baseDiv).val(); } }); ++; and --; are placeholders for where the adding and subtracting needs to happen. I just can't figure out how to get it to add or subtract from the correct value. Any help is appreciated. Thanks.

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  • Applying iterative algorithm to a set of rows from database

    - by Corvin
    Hello, this question may seem too basic to some, but please bear with be, it's been a while since I dealt with decent database programming. I have an algorithm that I need to program in PHP/MySQL to work on a website. It performs some computations iteratively on an array of objects (it ranks the objects based on their properties). In each iteration the algorithm runs through all collection a couple of times, accessing various data from different places of the whole collection. The algorithm needs several hundred iterations to complete. The array comes from a database. The straightforward solution that I see is to take the results of a database query and create an object for each row of the query, put the objects to an array and pass the array to my algorithm. However, I'm concerned with efficacy of such solution when I have to work with an array of several thousand of items because what I do is essentially mirror the results of a query to memory. On the other hand, making database query a couple of times on each iteration of the algorithm also seems wrong. So, my question is - what is the correct architectural solution for a problem like this? Is it OK to mirror the query results to memory? If not, which is the best way to work with query results in such an algorithm? Thanks!

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  • Strange Puzzle - Invalid memory access of location

    - by Rob Graeber
    The error message I'm getting consistently is: Invalid memory access of location 0x8 rip=0x10cf4ab28 What I'm doing is making a basic stock backtesting system, that is iterating huge arrays of stocks/historical data across various algorithms, using java + eclipse on the latest Mac Os X. I tracked down the code that seems to be causing it. A method that is used to get the massive arrays of data and is called thousands of times. Nothing is retained so I don't think there is a memory leak. However there seems to be a set limit of around 7000 times I can iterate over it before I get the memory error. The weird thing is that it works perfectly in debug mode. Does anyone know what debug mode does differently in Eclipse? Giving the jvm more memory doesn't help, and it appears to work fine using -xint. And again it works perfectly in debug mode. public static List<Stock> getStockArray(ExchangeType e){ List<Stock> stockArray = new ArrayList<Stock>(); if(e == ExchangeType.ALL){ stockArray.addAll(getStockArray(ExchangeType.NYSE)); stockArray.addAll(getStockArray(ExchangeType.NASDAQ)); }else if(e == ExchangeType.ETF){ stockArray.addAll(etfStockArray); }else if(e == ExchangeType.NYSE){ stockArray.addAll(nyseStockArray); }else if(e == ExchangeType.NASDAQ){ stockArray.addAll(nasdaqStockArray); } return stockArray; } A simple loop like this, iterated over 1000s of times, will cause the memory error. But not in debug mode. for (Stock stock : StockDatabase.getStockArray(ExchangeType.ETF)) { System.out.println(stock.symbol); }

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  • How to make link become inactive?

    - by Konstantin Vasilcov
    The idea was simple: change li background color on hover to one color ul#menu li a:hover {...} change it on mouse press to the other color ul#menu li a:active {...} return the color to the original (normal) if the link is neither hover nor pressed The problem appeared to be that, if user rejected his intention and lets the mouse up away from the link, the back color stays as if it was pressed. Then I tried to research and came up with this: ul#menu li a:hover:active {...} It became better, and the link is not marked with special back color in a normal state after user presses the link and rejects. But the "on-hover" back color became equal to the active one. So it looks like the link gets "active" state and stays in it even after user releases mouse button. Hate to write this, but I am very new to html and css. So I may be missing something very basic here. Could you, please, suggest any way, how to achieve my goal? EDIT I've read this source CSS Styling links (thought there could be some other state to use instead of active), but found nothing suitable there...

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