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  • Noob boost::bind member function callback question

    - by shaz
    #include <boost/bind.hpp> #include <iostream> using namespace std; using boost::bind; class A { public: void print(string &s) { cout << s.c_str() << endl; } }; typedef void (*callback)(); class B { public: void set_callback(callback cb) { m_cb = cb; } void do_callback() { m_cb(); } private: callback m_cb; }; void main() { A a; B b; string s("message"); b.set_callback(bind(A::print, &a, s)); b.do_callback(); } So what I'm trying to do is to have the print method of A stream "message" to cout when b's callback is activated. I'm getting an unexpected number of arguments error from msvc10. I'm sure this is super noob basic and I'm sorry in advance.

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  • Strange/simple batch question regarding Java/Ant

    - by Monster
    For my company, I'm making a batch script to go through and compile the latest revisions of code for our current project. I'm using Ant to build the class files, but encountered a strange error. One of the source files imports .* from a directory, where there are no files (only folders), and in fact, the folders needed are imported right after. It compiles perfectly fine in Eclipse, but I'm using an Ant script to automate it outside of the IDE, and Javac throws an error when it encounters this line. Is there any automated procedure I can use to ignore/suppress this error with javac in Ant? I'd even go so far as to create a dummy file in the importing directory, but all of that in contained in a Jar file I don't wish to have to decompress and then recompress with the dummy file. Thanks!

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  • Basic Question on storing variables c# for use in other classes

    - by Calibre2010
    Ok guys I basically have a class which takes in 3 strings through the parameter of one of its method signatures. I've then tried to map these 3 strings to global variables as a way to store them. However, when I try to call these global variables from another class after instantiating this class they display as null values. this is the class which gets the 3 strings through the method setDate, and the mapping.. public class DateLogic { public string year1; public string month1; public string day1; public DateLogic() { } public void setDate(string year, string month, string day) { year1 = year; month1 = month; day1 = day; // getDate(); } public string getDate() { return year1 + " " + month1 + " " + day1; } } After this I try call this class from here public static string TimeLine2(this HtmlHelper helper, string myString2) { DateLogic g = new DateLogic(); string sday = g.day1; string smonth = g.month1; string syr = g.year1; } I've been debugging and the values make it all the way to the global variables but when called from this class here it doesnt show them, just shows null. Is this cause I'm creating a brand new instance, how do i resolve this?

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  • Java appliction design question

    - by ring bearer
    Hi I have a hobby project, which is basically to maintain 'todo' tasks in the way I like. One task can be described as: public class TodoItem { private String subject; private Date dueBy; private Date startBy; private Priority priority; private String category; private Status status; private String notes; } as you can imagine I would have 1000 todo items at a given time. What is the best strategy to store a todo item? (currently on an XML file) such that all the items are loaded quickly up on app start up(the application shows kind of a dashboard of all the items at start up) What is the best way to design its back-end so that it can be ported to android/or a J2ME based phone Currently this is done using java swing. What should be the concerns so that it works efficiently on a device where memory is limited? Thanks!

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  • An update question !

    - by rantravee
    Hi , Here's the problem I'm facing : trying to do my own application update I download the update apk from a web server on the sd card and then I launch the Package Installer with the downloading path ( while the old application is running) . So far after the package installer starts and the user agrees to install the application I get the following message " MyApp Could not be installed on this phone" and in the logcat then following message is printed : "No package identifier when getting value for resource number 0x00000000" . I could not find a reason for this behaviour , so please if there is something that I'm missing do point it to me !

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  • Jquery selector question

    - by fizzer
    Hi, I have a working selector but I just wondered whether there was another way I could write it. Here's the html structure: THIS IS TEXT I WANT TO SELECT item 1 item 2 item 3 I have a click event attached to the nested listitems. In the click event I am trying to select the anchor tag. I have used the follwing selector: $(this).parents('li').children('a') Is this the most efficient way of selecting the anchor tag?

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  • Question regarding ip checksum code

    - by looktt
    unsigned short /* this function generates header checksums */ csum (unsigned short *buf, int nwords) { unsigned long sum; for (sum = 0; nwords > 0; nwords--) // add words(16bits) together sum += *buf++; sum = (sum >> 16) + (sum & 0xffff); //add carry over sum += (sum >> 16); //what does this step do??? add possible left-over //byte? But isn't it already added in the loop (if //any)? return ((unsigned short) ~sum); } I assume nwords in the number of 16bits word, not 8bits byte (if there are odd byte, nword is rounded to next large), is it correct? The line sum = (sum 16) + (sum & 0xffff) is to add carry over to make 16bit complement sum += (sum 16); What's the purpose of this step? Add left-over byte? How? Thanks!

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  • JavaScript Object Question

    - by Frank Neville
    What I want to do with the fs object is to add multiple "items" to the fs.items property. How can I do this? You can see my attempt below, obviously this does not work. I am a beginner, go easy on me :) Thanks... var fs = { name:'test', items:[] }; fs.items = { name:'item1', value:1 }; fs.items = { name:'item2', value:2 }

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  • mvc contrib pager question - AsPagination

    - by csetzkorn
    Hi, I might be wrong but is the AsPagination method not very inefficient as it sucks all the data from a repository first to initialise TotalItems etc.? So paging is not used to make the data access more efficient. I have not found any examples which use a repository and 'true' paging (i.e. uses TOP etc. in the atcual SQL). How do I use the Pager if I have a repository method with this signature: IList GetData(int? page, out int TotalItems) Any feedback would be very much appreciated. Thanks. Christian

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  • Axis Rotation Question using sio2 game engine

    - by Leo
    By using left hand rule, I rotate one object left and right using x axis, and rotate up/down using y axis. After first object is rotated to the right, the up/down rotation should be using z axis. However, when I try to rotate using z axis, after the first rotation, it has the same effect when I rotate using y axis. Anyone has any ideas? Thanks

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  • Question about Architecture for Viewing Images in ASP.NET MVC App

    - by Charlie Flowers
    I have an approach in mind for an image viewer in a web app, and want to get a sanity check and any thoughts you stackoverflowers might have. Here's the whirlwind nutshell summary: I'm working on an ASP.NET MVC application that will run in my company's retail stores. Even though it is a web application, we own the store machines and have control over them. We have a "windows agent" running on the store machine which we can talk to from the browser via javascript (it is a WCF service, and our web app has permission to talk to it from the browser). One of the web pages needs to be an "image viewer" page with some common things like Rotate & Zoom. Now, there are some WebForms controls that offer Rotate and Zoom. However, they take up server resources and generate a good bit of traffic between the server and the browser. For example, the Rotate function would cause an ajax call to the server, which would then generate a new image written to a .NET Canvas object, which would then be written to a file on the server, which would then be returned from the ajax call and refreshed inside the browser. Normally, that's a pretty good way of doing things. But in our case, we have code running on the store machine that we can communicate with. This leads me to consider the following approach: When the user asks to view an image, we tell our "windows agent" to download it from our image server to the store machine. We then redirect our browser to our image viewer page, which will pull the image from the local file we just wrote to the store machine. When the user clicks "Rotate", we cause JavaScript code in the browser to call our "windows agent" software, asking it to perform the "Rotate" function. The "windows agent" does the rotation using the same kind of imaging control that would formerly have been used on the server, but it does so now on the store machine. Javascript in the browser then refreshes the image on the page to show the newly rotated image. Zoom and similar features would be implemented the same way. This seems to be much more efficient, scalable, and responsive for the end-users. However, I've never heard of anything like it being done, mostly because it's rare to have this combination of a web app plus a "windows agent" on the client machine. What do you think? Feasible? Reasonable? Any pitfalls I overlooked or improvements / suggestions you can see? Has anyone done anything like this who would like to offer the wisdom of experience? Thanks!

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  • Recursion Question : Revision

    - by stan
    My slides say that: A recursive call should always be on a smaller data structure than the current one There must be a non recursive option if the data structure is too small You need a wrapper method to make the recursive method accessible Just reading this from the slides makes no sense, especially seeing as it was a topic from before christmas! Could anyone try and clear up what it means please? Thank you

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  • Question about [Pure] methods

    - by devoured elysium
    Is the following method Pure? I'd say so, as it doesn't change in anyway the current class, thus, everything we can now currenly "see" in the class, before running this method will still be exactly the same after. Am I correct? class Set { ... public ISet<T> UnionWith(ISet<T> set) { ISet<T> unionSet = ... foreach (Element element in this) { unionSet.Add(element); } foreach (Element element in set) { unionSet.Add(element); } return unionSet; } }

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  • Python CLI tool - general parsing question

    - by WinkyWolly
    If possible I would like to use the following structure for a command however I can't seem to figure out how to achieve this in Python: ./somescript.py arg <optional argument> -- "some long argument" Would it be possible to achieve this in a feasible manner without too much dirty code? Or should I just reconsider the syntax (which is primarily preference). Thanks!

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  • Small Python optional arguments question

    - by ooboo
    I have two functions: def f(a,b,c=g(b)): blabla def g(n): blabla c is an optional argument in function f. If the user does not specify its value, the program should compute g(b) and that would be the value of c. But the code does not compile - it says name 'b' is not defined. How to fix that? Someone suggested: def g(b): blabla def f(a,b,c=None): if c is None: c = g(b) blabla But this doesn't work, because maybe the user intended c to be None and then c will have another value.

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  • Beginner to RUBY - Array Question

    - by WANNABE
    a = [ 1, 3, 5, 7, 9 ] ? [1, 3, 5, 7, 9] a[2, 2] = ’cat’ ? [1, 3, "cat", 9] a[2, 0] = ’dog’ ? [1, 3, "dog", "cat", 9] a[1, 1] = [ 9, 8, 7 ] ? [1, 9, 8, 7, "dog", "cat", 9] a[0..3] = [] ? ["dog", "cat", 9] a[5..6] = 99, 98 ? ["dog", "cat", 9, nil, nil, 99, 98] I can understand how the last four amendments to this array work, but why do they use a[2, 2] = 'cat' and a[2,0] = 'dog' ??? What do the two numbers represent? Couldnt they just use a[2] = 'dog'?

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  • Newbie question: undefined local variable or method , why??

    - by Mellon
    I am new in Rails (I am using Rails 3.0.3), currently I am following the book "Agile Web Development with Rails" to develop a simple rails application. I followed the book to: --create a model 'Cart' class; --implement 'add_to_cart' method in my 'store_controller', I have a line of code <%=button_to "Add to Cart", :action => add_to_cart, :id => product %> in my /store/index.html.erb As you see, there is :action => add_to_cart in my index.html.erb, which will invoke the add_to_cart method in my *Controllers/store_controller.rb* But after I refresh the browser, I got the error "undefined local variable or method 'add_to_cart'", apparently I do have the method add_to_cart in my 'store_controller.rb', why I got this error??? What is the possible cause??? Here are my codes: store_controller.rb class StoreController < ApplicationController def index @products = Product.find_products_for_sale end def add_to_cart product = Product.find(params[:id]) @cart = find_cart @cart.add_product(product) end private def find_cart session[:cart] ||= Cart.new end end /store/index.html.erb <h1>Your Pragmatic Catalog</h1> <% @products.each do |product| -%> <div class="entry"> <%= image_tag(product.image_url) %> <h3><%=h product.title %></h3> <%= product.description %> <div class="price-line"> <span class="price"><%= number_to_currency(product.price) %></span> <!-- START_HIGHLIGHT --> <!-- START:add_to_cart --> **<%= button_to 'Add to Cart', :action => 'add_to_cart', :id => product %>** <!-- END:add_to_cart --> <!-- END_HIGHLIGHT --> </div> </div> <% end %> Model/cart.rb class Cart attr_reader :items def initialize @items = [] end def add_product(product) @items << product end end

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  • Some question about Zend_Auth and Zend_Session

    - by user1400
    I want to Zend_Auth and Zend_Session to save user sessions and logins information whats the easy and best way for implements following items: 1-Disallow multiple concurrent logins for the specific user 2-List all of all user currently logged in 3-Admin could logout of specific user or destroy specific session Is there any special ZF or PHP API or library that can do the above? thanks

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  • Question about WeakHashMap

    - by michael
    Hi, In the Javadoc of "http://java.sun.com/j2se/1.4.2/docs/api/java/util/WeakHashMap.html", it said "Each key object in a WeakHashMap is stored indirectly as the referent of a weak reference. Therefore a key will automatically be removed only after the weak references to it, both inside and outside of the map, have been cleared by the garbage collector." And then Note that a value object may refer indirectly to its key via the WeakHashMap itself; that is, a value object may strongly refer to some other key object whose associated value object, in turn, strongly refers to the key of the first value object. But should not both Key and Value should be used weak reference in WeakHashMap? i.e. if there is low on memory, GC will free the memory held by the value object (since the value object most likely take up more memory than key object in most cases)? And if GC free the Value object, the Key Object can be free as well? Basically, I am looking for a HashMap which will reduce memory usage when there is low memory (GC collects the value and key objects if necessary). Is it possible in Java? Thank you.

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  • jQuery plugin question - populate select options with JSON data

    - by user331884
    I'm trying to fill selects with json data from a web service. I'm getting error 'Object doesn't support this property or method.' when I do this $(this).html(options.join'')); Any ideas what I'm doing wrong? ;(function($) { $.fillSelect = {}; $.fn.fillSelect = function(url, map) { var jsonpUrl = url + "?callback=?"; $.getJSON(jsonpUrl, function(d) { var options = []; var txt = map[0]; var val = map[1]; options.push('<option>--Select--</option>'); $.each(d, function(index, item) { options.push('<option value="' + item[val] + '">' + item[txt] + '</option>'); }); $(this).html(options.join('')); //getting error Object doesn't support this property or method } }; })(jQuery);

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  • Flex 4 animation question

    - by Jerry
    Hello.. I am trying to do the move vertically animation on a button nested in the vertical layout. I am not sure if the Hgroup restricts the button moving vertically. Are there ways to go around it? Thanks for the helps. <s:states> <s:State name="default"/> <s:State name="addRecommend"/> <s:State name="seeOther"/> </s:states> AS: protected function add_clickHandler(event:MouseEvent):void { currentState="addRecommend"; addRecommendMove.play(); } <s:transitions> <s:Transition fromState="default" toState="addRecommend"> <s:Sequence id="addRecommendMove"> <s:Move yTo="50" target="{add}"/> // add button doesn't move at all </s:Sequence> </s:Transition> <s:Transition fromState="addRecommend" toState="seeOther"> <s:Sequence> <s:Move yBy="50" target="{seeOthers}"/> </s:Sequence> </s:Transition> </s:transitions> <s:layout> <s:VerticalLayout paddingTop="15" paddingRight="10" paddingLeft="7"/> </s:layout> <button id="add" click=add_clickHandler(event)/> <button id="seeOthers"/>

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  • EmulateIE7 and FRAMES Question

    - by JJ
    I don't want to have to add the EmulateIE7 meta tag for every page if I dont have to. My default.htm is a FRAMESET page so can I just add the meta tag to my default FRAMESET page and my site stay in IE=EmulateIE7 mode for each new page that loads in the frameset? Thanks

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  • basic question with a dtd

    - by voodoomsr
    i need an element with the characteristics <!ELEMENT section ((comment*)|definition|(comment*))> but that is ambiguous, i get the next message in visual studio Multiple definition of element 'comment' causes the content model to become ambiguous. A content model must be formed such that during validation of an element information item sequence, the particle contained directly, indirectly or implicitly therein with which to attempt to validate each item in the sequence in turn can be uniquely determined without examining the content or attributes of that item, and without any information about the items in the remainder of the sequence. So how can i write correctly that? the correct structure is one definition surrounded by possibles comments elements.

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  • jQuery plugin .fn question

    - by user319342
    Hello, I seem to be having some problems creating a jquery plugin. I am testing a simple plugin in firebug console and the function is not being defined as I would expect. Here is the code pattern I am using jQuery.fn.test = function () {console.log("runs")} I am trying to call the function with this call which is not working. $.test() But this call does $.fn.test() I don't think this is how it is supposed to work so I think I am doing something wrong, although all the documentation seems to agree that I should be correct. Any one have any advice? Thanks, Cory

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