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  • Finding subsets that can be completed to tuples without duplicates

    - by Jules
    We have a collection of sets A_1,..,A_n. The goal is to find new sets for each of the old sets. newA_i = {a_i in A_i such that there exist (a_1,..,a_n) in (A1,..,An) with no a_k = a_j for all k and j} So in words this says that we remove all the elements from A_i that can't be used to form a tuple (a_1,..a_n) from the sets (A_1,..,A_n) such that the tuple doesn't contain duplicates. My question is how to compute these new sets quickly. If you just implement this definition by generating all possible v's this will take exponential time. Do you know a better algorithm? Edit: here's an example. Take A_1 = {1,2,3,4} A_2 = {2}. Now the new sets look like this: newA_1 = {1,3,4} newA_2 = {2} The 2 has been removed from A_1 because if you choose it the tuple will always be (2,2) which is invalid because it contains duplicates. On the other hand 1,3,4 are valid because (1,2), (3,2) and (4,2) are valid tuples. Another example: A_1 = {1,2,3} A_2 = {1,4,5} A_3 = {2,4,5} A_4 = {1,2,3} A_5 = {1,2,3} Now the new sets are: newA_1 = {1,2,3} newA_2 = {4,5} newA_3 = {4,5} newA_4 = {1,2,3} newA_5 = {1,2,3} The 1 and 2 are removed from sets 2 and 3 because if you choose the 1 or 2 from these sets you'll only have 2 values left for sets 1, 4 and 5, so you will always have duplicates in tuples that look like (_,1,_,_,_) or like (_,_,2,_,_).

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  • Lazarus - why I can't assign event to run-time component?

    - by Garret Raziel
    Hello, I have this Lazarus program: unit Unit2; {$mode objfpc}{$H+} interface uses Classes, SysUtils, FileUtil, LResources, Forms, Controls, Graphics, Dialogs, StdCtrls, ComCtrls; type { TForm2 } TForm2 = class(TForm) procedure OnTlacitkoClick(Sender: TObject); procedure FormClose(Sender: TObject; var CloseAction: TCloseAction); procedure FormCreate(Sender: TObject); tlac:TButton; private { private declarations } public { public declarations } end; var Form2: TForm2; implementation { TForm2 } procedure TForm2.OnTlacitkoClick(Sender: TObject); begin showmessage('helloworld'); end; procedure TForm2.FormCreate(Sender: TObject); var i,j:integer; begin tlac:=TButton.Create(Form2); tlac.OnClick:=OnTlacitkoClick; tlac.Parent:=Form2; tlac.Left:=100; tlac.Top:=100; end; initialization {$I unit2.lrs} end. but compiler says: unit2.pas(63,32) Error: Wrong number of parameters specified for call to "OnTlacitkoClick" in tlac.OnClick:=OnTlacitkoClick; expression. I have searched and think that this is legal expression in Delphi. I want simply to registrate OnTlacitkoClick as tlac.OnClick event,not to call this procedure. Is there somethink wrong with the code or must I do it different in Lazarus/Freepascal? Thanks.

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  • C-macro: set a register field defined by a bit-mask to a given value

    - by geschema
    I've got 32-bit registers with field defined as bit-masks, e.g. #define BM_TEST_FIELD 0x000F0000 I need a macro that allows me to set a field (defined by its bit-mask) of a register (defined by its address) to a given value. Here's what I came up with: #include <stdio.h> #include <assert.h> typedef unsigned int u32; /* * Set a given field defined by a bit-mask MASK of a 32-bit register at address * ADDR to a value VALUE. */ #define SET_REGISTER_FIELD(ADDR, MASK, VALUE) \ { \ u32 mask=(MASK); u32 value=(VALUE); \ u32 mem_reg = *(volatile u32*)(ADDR); /* Get current register value */ \ assert((MASK) != 0); /* Null masks are not supported */ \ while(0 == (mask & 0x01)) /* Shift the value to the left until */ \ { /* it aligns with the bit field */ \ mask = mask >> 1; value = value << 1; \ } \ mem_reg &= ~(MASK); /* Clear previous register field value */ \ mem_reg |= value; /* Update register field with new value */ \ *(volatile u32*)(ADDR) = mem_reg; /* Update actual register */ \ } /* Test case */ #define BM_TEST_FIELD 0x000F0000 int main() { u32 reg = 0x12345678; printf("Register before: 0x%.8X\n", reg);/* should be 0x12345678 */ SET_REGISTER_FIELD(&reg, BM_TEST_FIELD, 0xA); printf("Register after: 0x%.8X\n", reg); /* should be 0x123A5678 */ return 0; } Is there a simpler way to do it?

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  • How do I duplicate Facebook picture tagging functionality?

    - by marcamillion
    I asked this question in another post - http://stackoverflow.com/questions/2597773/how-do-i-put-a-div-box-around-my-cursor-on-click I got a wonderful answer. See the code below: <script type="text/javascript"> $(document).ready(function() { $("#image-wrapper").click(function(e){ var ele = $("<div>"); ele.css({width:"50px", height:"50px", border:"1px solid green", position:"absolute", left: e.pageX - 25, top: e.pageY -25}); $("body").append(ele); }); }); </script> <div id="image-wrapper" style="border: 1px solid red; width: 300px; height: 200px;"> </div> The issue I am having is that when I implement this snippet, on every click a box appears and stays there. So if I click on the image 10 times, I get 10 boxes. How do I get the previous box to disappear once I click somewhere else (i.e. have the box move to another place on the image (just like with Facebook Picture Tagging))? Thanks.

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  • WPF toolbar disappearing on resize

    - by user1122909
    On my main form I have a toolbar with a number of buttons. Once the parent form is resized down by dragging it so that the entire toolbar with all its buttons no longer fits in the width of the window, the whole toolbar disappears. Is there a way I can make it so that as you resize it, when you get to the width of the toolbar the inner controls of the form stop resizing and stay displayed, just cut off where the window has resized to? Code is <Grid > <Grid.RowDefinitions> <RowDefinition Height="Auto" /> <RowDefinition Height="Auto" /> <RowDefinition Height="*" /> <RowDefinition Height="Auto" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <ToolBar Grid.Row="1" Height="50" Name="tbMainToolbar" VerticalAlignment="Top" MinWidth="900" > <ToolBar.Background> <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.5,1"> <GradientStop Color="White" Offset="0.0" /> <GradientStop Color="#DCEBFF" Offset="0.25" /> <GradientStop Color="#99CCFF" Offset="0.75" /> <GradientStop Color="#99CCFF" Offset="1.0" /> </LinearGradientBrush> </ToolBar.Background> <DockPanel LastChildFill="True"> <Button Name="btnApproved" DockPanel.Dock="Left" Click="btnToolbar_Click" CommandParameter="APPROVED" Style="{StaticResource ToolbarButtonDisplay}" HelperClasses:ButtonProperties.Image="..\..\Resources\Images\APPROVEU.GIF" Content="Approve"> </Button> ... and so forth for about 20 buttons

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  • What ever happened to APL?

    - by lkessler
    When I was at University 30 years ago, I used a programming language called APL. I believe the acronym stood for "A Programming Language", This language was interpretive and was especially useful for array and matrix operations with powerful operators and library functions to help with that. Did you use APL? Is this language still in use anywhere? Is it still available, either commercially or open source? I remember the combinatorics assignment we had. It was complex. It took a week of work for people to program it in PL/1 and those programs ranged from 500 to 1000 lines long. I wrote it in APL in under an hour. I left it at 10 lines for readability, although I should have been a purist and worked another hour to get it into 1 line. The PL/1 programs took 1 or 2 minutes to run on the IBM mainframe and solve the problem. The computer charge was $20. My APL program took 2 hours to run and the charge was $1,500 which was paid for by our Computer Science Department's budget. That's when I realized that a week of my time is worth way more than saving some $'s in someone else's budget. I got an A+ in the course. p.s. Don't miss this presentation entitled: "APL one of the greatest programming languages ever"

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  • Writing to a new window with javascript... get access denied

    - by Søren
    Hello gurus :) I have been struggling with this for a while now, and decided it was time to ask for help. I am trying to create a print function on an aspx page, and I am using javascript to do this: function PrintContentCell() { var display_setting = "toolbar=yes, location=no, directories=yes, menubar=yes,"; display_setting += "scrollbars=yes, width=750, height=600, left=100, top=25"; var content_innerhtml = document.getElementById("testTable").innerHTML; var document_print = window.open("Loading.htm", "", display_setting); document_print.document.open(); document_print.document.write('<html><head><title>Print</title></head>'); document_print.document.write('<body style="font-family:verdana; font-size:12px;" onLoad="self.print();self.close();" >'); document_print.document.write(content_innerhtml); document_print.document.write('</body></html>'); document_print.print(); document_print.document.close(); return false; } I get "Access Denied" when the script tries to write to the new window. The Loading.htm file is just a very slim html document writing out the text "Loading...". I had hoped this would work after reading this thread: http://stackoverflow.com/questions/735136/ie-6-7-access-denied-trying-to-access-a-popup-window-document Anybody can help?

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  • Latex renewcommand not working properly

    - by Nazgulled
    Why is this not working: \documentclass[a4paper,10pt]{article} \usepackage{a4wide} \usepackage[T1]{fontenc} \usepackage[portuguese]{babel} \usepackage[latin1]{inputenc} \usepackage{indentfirst} \usepackage{listings} \usepackage{fancyhdr} \usepackage{url} \usepackage[compat2,a4paper,left=25mm,right=25mm,bottom=15mm,top=20mm]{geometry} \usepackage{color} \usepackage[colorlinks]{hyperref} \usepackage[pdftex]{graphicx} \renewcommand{\headrulewidth}{0.4pt} \renewcommand{\footrulewidth}{0.4pt} \pagestyle{fancy} \fancyhead[L]{\small Laboratórios de Informática III} \fancyhead[R]{\small Projecto 1 (Linguagem \textsf{C})} \lstset{ basicstyle=\ttfamily\footnotesize, showstringspaces=false, frame=single, tabsize=4, breaklines=true, } \definecolor{Section1}{rgb}{0.09,0.21,0.36} \definecolor{Section2}{rgb}{0.21,0.37,0.56} \definecolor{Section3}{rgb}{0.30,0.50,0.74} \hypersetup{ bookmarks=false, linkcolor=red, urlcolor=cyan, } \renewcommand{\section}[1]{\texorpdfstring{\color{green}#1}{#1}} \parskip=6pt \begin{document} \begin{titlepage} \begin{center} \includegraphics[width=5cm]{./logo.jpg}\\[1cm] \textsc{\LARGE Universidade do Minho}\\[1cm] \textsc{\large Licenciatura em Engenharia Informática\\Laboratórios de Informática III}\\[1.5cm] \rule{\linewidth}{0.5mm}\\[0.4cm] \huge{\textbf{\textsc{Relatório do Projecto 1 (Linguagem C)}}} \rule{\linewidth}{0.5mm} \vfill \begin{tabular}{c c} \includegraphics[width=3.5cm]{./nuno.jpg} & \includegraphics[width=3.5cm]{./ricardo.jpg} \\ \textsc{\large{Nuno Mendes (51161)}} & \textsc{\large{Ricardo Amaral (48404)}} \\ \end{tabular} \vfill \large{\today} \end{center} \end{titlepage} \tableofcontents \newpage \section{Introdução} Lorem ipsum... \newpage \appendix \section{\color{Section1}Diagrama das Estruturas de Dados} \begin{center} \includegraphics[width=16cm]{./Diagrama.pdf} \end{center} \end{document} ! LaTeX Error: Something's wrong--perhaps a missing \item. See the LaTeX manual or LaTeX Companion for explanation. Type H for immediate help. ... l.2 ...rline {1}\color {green}Teste}{3}{section.1} How can I make it work properly?

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  • Resize a UITableView to accomodate a translucent header before it becomes visible

    - by scotru
    I have a UITableView inside a UINavigationController. The navigation controller uses a translucent navigation bar--as a result, my table view is displayed behind the navigation bar and it's height includes the height of the navigation bar. However, I want the table view to appear below the navigation bar (as it would if it were not translucent). I'm working in MonoTouch, but I think the principles are language independent. Here's the code I'm using to resize the UITableView frame: RectangleF rect = tableView.Frame; tableView.Frame = new RectangleF (rect.Left, rect.Top + 44, rect.Width, rect.Height - 44); tableView.ContentInset = new UIEdgeInsets (0, 0, 0, 0); This works fine if I place it in the viewDidAppear method, but will not work in the viewWillAppear method. In the viewDidAppear method, however I can see the resize occurring briefly in the form of a flicker. I want to do the resize before the frame appears. But if I put this code in viewWillAppear or viewDidLoad, it has no effect. Thanks in advance for any help!

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  • Show NotifyIcon Context Menu and Control Its Position?

    - by Shawn O'Hern
    I'm trying to show a context menu when I left-click a NotifyIcon. Just calling NotifyIcon.ContextMenuStrip.Show() doesn't work very well. A solution has been posted here before that calls a secret method using Reflection: Dim mi As System.Reflection.MethodInfo = GetType(NotifyIcon).GetMethod("ShowContextMenu", Reflection.BindingFlags.Instance Or Reflection.BindingFlags.NonPublic) mi.Invoke(Icon, Nothing) This works great, except that I also need to control where the menu is shown. I want to wait for the SystemInformation.DoubleClickTime to elapse between receiving the NotifyIcon.MouseUp event and displaying the menu, so that I can handle single-clicks and double-clicks separately. But invoking the ShowContextMenu method displays the menu at the current mouse position when ShowContextMenu is called, not when the icon was actually clicked. Which means that if the mouse moved during the DoubleClickTime, the menu will be displayed in a different part of the screen. So if I can control where the menu is shown, I can just save the mouse coordinates when I receive the MouseUp event, and then I can ensure that the menu is displayed near the icon. Is there a way to do this? Thanks in advance.

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  • Position an icon on the right in the middle of a list item

    - by Andy
    I have the following code which prints an img if the current page is selected. The issue i have is if the list item is a varied height i cant position it in the middle of the list item on the far right... <li><?php echo $child->link($child->title); ?><?php echo (url_start_with($child->url) ? '<img src="images/ico-arrow.png" class="pointer">': null); ?></li> how can i ammend the "TOP" so that it will position itself vertically no matter what the height using css #bf-fest-list li { margin:0; padding:5px 25px; position:relative; } #bf-fest-list li a:hover { color:#ec1c23; text-decoration:none; } #bf-fest-list li.current { background:#a0a1a4; padding:10px 25px; } #bf-fest-list li.current a { color:#FFF; } #bf-fest-list li .pointer { position:absolute; top:10px; left:233px; }

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  • Redraw and flicker issues

    - by AngryHacker
    I have an Outlook style app. So basically I have a sidebar on the left and on the right I have a panel control (pnlMainBody) that hosts content. The content is typically a user control that I add to the panel when user clicks appropriate button in the side bar. The way I add the user control to the panel is as follows: // _pnlEmails is the User Control that I am adding to the panel _pnlEmails = new pnlEmails(); _pnlEmails.Dock = DockStyle.Fill; this.pnlMainBody.Controls.Add(_pnlEmails); Some of the user controls that I add to the main panel are quite complex UI-wise. So when this.pnlMainBody.Controls.Add(_pnlEmails); fires, I see the control appear on the screen, then it resizes itself to fill the body of the panel control. It's quite ugly actually, so I was wondering whether there is a way to not show the resizing until it's actually done resizing? I've tried setting the user control's .Visible to false. I've tried doing .SuspendLayout, all to no avail. Is there a way to do this so the screen transitions are smooth?

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  • How to share internet over VPN and inside a virtual machine (Windows)?

    - by mountrix
    ` My final goal is to have a virtual machine at work in which anything that happen inside (tcp, udp, ping, ...) will use the Internet connection of a computer at home. So, if inside this VM should I open an Internet browser to a site such as "show my IP", my home IP should be printed. I am also looking for a way to debug/develop a software inside this VM, but I would like to tunnel only the connections of this software, not the full graphical interface, this is why a Remote Desktop solution won't fit me. The connection between the both computer should be secured somehow, like in a SSH tunnel. This ultimately should allow me to have a portable VM in which I can connect to whatever networks I have access at home, in a secure way. This is my configuration: At work, I have a LAN-connected desktop computer, with Windows 7 Professional Edition as a host [computer W] On this same computer, I have a Virtual Box machine running Windows XP [computer V] At home, I have a laptop computer, running Windows 7 Home Edition [computer H] This laptop is connected to a Livebox 2 broadband modem by Wifi. What I am trying to do is to sit at work in front of the virtual machine [V], and connect to a webpage as if the request was issued from the laptop [H] at home, and the data should be securely tunneled between the both. But if I am using internet directly inside [W], it should use the normal LAN interface at work. To achieve my goal, I first try using VPN, than SSH tunneling, without success. I first tried to install Teamviewer between [W] and [H]. This is working fine, I can send files, share desktop, etc. Teamviewer has a VPN mode that creates a new VPN network interface with its own IP, both on computer [W] and [H]. This allowed me to connect [H] as a network computer inside [W] and I was able to share files, but not to share Internet. At this point, I tried to use from [W] the Internet as if I was at home. I setup a route (using route add from command line in [W]) in order to instruct each packet going to a given website to pass by the new VPN interface on [W], with the hope it will be forwarded to [H], but the webpage was simply inaccessible. I then tried to setup a Windows VPN connection between [W] and [H], using the Windows 7 VPN feature. [H] was the server and [W] the client. But it failed: I got the "Unable to join a remote PC while trying to VPN" 720 Error when I was setting up the client on [W]. I think the problem is the Livebox 2 that could blocks the packets. But I am not sure of this: 1) with Teamviewer it works fine, 2) Livebox 2 has a configuration page for port mapping that gives the proper configuration to map VPN ports as an example so I guess that it should allow it, 3) I opened the ports 1723 (TCP) and 500 (UDP) according to some forums. Virtual box has a network configuration parameter in which I can use the VPN network interface created by Teamviewer as a bridged connection. This is suppose to work in the sense that all packets issued by the virtual machine [V] is supposed to go directly to [H]. But I had no internet connection inside [V]. Using the NAT mode, [V] has internet. For me this is the feature that I look for: filtering all connections from the virtual box application to the VPN network interface, and the remaining should use the normal LAN interface. Apart from the build-in feature of VBox, I even do not know if it is possible to route the packet from a given application to a given interface. Finally I tried also SSH tunneling, but this is not the solution I looked for. Using an external SSH server (Linux), I was able to create a localhost connection on [W] (or [V]), using something like 'ssh -N -D server[H]' in order to allow a web browser located in [W] to connect to any website using the SOCKS 5 proxy created locally (SOCKS is a build-in feature of SSH). But repeating the same operation on windows, using a windows SSH server inside [W] (I tried freeSSHd), it failed: SFTP worked, but not the SOCKS tunneling, it was like the browser in [H] did not find internet. Finally only Teamviewer looked able to create a VPN between [W] and [H], but I am not able to use it, as I want, I mean using the Internet connection of [H] sitting in front of [W]. I also tried to bridge the VPN interface and the wifi interface inside [H], but it blocked my laptop, and I tried also the Internet Connection Sharing, trying to share on [H] the wifi connection over the VPN interface. This fails also, but it seems because Teamviewer actually use the wifi interface to be able to provide the VPN link, so I guess I am creating a recursive loop. I do not know what to try next... Thank you for any advice!!

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  • Clojure agents consuming from a queue

    - by erikcw
    I'm trying to figure out the best way to use agents to consume items from a Message Queue (Amazon SQS). Right now I have a function (process-queue-item) that grabs an items from the queue, and processes it. I want to process these items concurrently, but I can't wrap my head around how to control the agents. Basically I want to keep all of the agents busy as much as possible without pulling to many items from the Queue and developing a backlog (I'll have this running on a couple of machines, so items need to be left in the queue until they are really needed). Can anyone give me some pointers on improving my implementation? (def active-agents (ref 0)) (defn process-queue-item [_] (dosync (alter active-agents inc)) ;retrieve item from Message Queue (Amazon SQS) and process (dosync (alter active-agents dec))) (defn -main [] (def agents (for [x (range 20)] (agent x))) (loop [loop-count 0] (if (< @active-agents 20) (doseq [agent agents] (if (agent-errors agent) (clear-agent-errors agent)) ;should skip this agent until later if it is still busy processing (not sure how) (send-off agent process-queue-item))) ;(apply await-for (* 10 1000) agents) (Thread/sleep 10000) (logging/info (str "ACTIVE AGENTS " @active-agents)) (if (> 10 loop-count) (do (logging/info (str "done, let's cleanup " count)) (doseq [agent agents] (if (agent-errors agent) (clear-agent-errors agent))) (apply await agents) (shutdown-agents)) (recur (inc count)))))

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  • Newbie question: How do you layout an icon, 2 text lines and a button?

    - by Keith Barrows
    I am trying to extend a sample I found at http://developer.android.com/resources/articles/layout-tricks-efficiency.html. I am a brand new MonoDroid developer, just installed it yesterday, and trying to jump right into UI design and so far it is not clicking for me completely. I have this main.xml: <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="?android:attr/listPreferredItemHeight" android:padding="6dip"> <ImageView android:id="@+id/icon" android:layout_width="wrap_content" android:layout_height="fill_parent" android:layout_alignParentTop="true" android:layout_alignParentBottom="true" android:layout_marginRight="6dip" android:src="@drawable/icon" /> <TextView android:id="@+id/secondLine" android:layout_width="200dip" android:layout_height="26dip" android:layout_toRightOf="@id/icon" android:layout_alignParentBottom="true" android:layout_alignParentRight="true" android:singleLine="true" android:ellipsize="marquee" android:text="Second line which is a long line of text and needs to scroll" /> <TextView android:id="@+id/firstLine" android:layout_width="200dip" android:layout_height="wrap_content" android:layout_toRightOf="@id/icon" android:layout_alignParentRight="true" android:layout_alignParentTop="true" android:layout_above="@id/secondLine" android:layout_alignWithParentIfMissing="true" android:singleLine="true" android:ellipsize="marquee" android:gravity="center_vertical" android:text="First line" /> <Button android:id="@+id/logonButton" android:layout_width="50dip" android:layout_height="wrap_content" android:layout_toRightOf="@id/secondLine" android:layout_alignParentRight="true" android:layout_alignParentTop="true" android:gravity="center_vertical" android:text="Login" /> /> </RelativeLayout> What I am trying to do is have an icon on the left, 2 lines of text stacked in the middle and a button on the right. When I run this in my emulator I am seeing: The second line is not scrolling. The button does not show up. Is there by any chance a simple WYSIWYG editor for layout? Or is there an app to give me a quick view of my layout XML? Something like FireBug in FireFox would be fine. Barring the slim chance there are UI helpers for Droid, what am I doing wrong? :)

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  • Scrolling down to next element via keypress & scrollTo plugin - jQuery

    - by lyrae
    I am using jQuery's scrollTo plugin to scroll up and down my page, using UP arrow and DOWN arrow. i have a bunch of div with class "screen", as so: <div class="screen-wrapper">...</div> What I am trying to do is, when i press UP or DOWN, the window scrolls to the next, or previous div with class of "screen". I have the keypresses taken care of. According to the plugin docs, to scroll a window, you use $.scrollTo(...); Here's the code I have: $(document).keypress(function(e){ switch (e.keyCode) { case 40: // down n = $('.screen-wrapper').next() $.scrollTo( n, 800 ); break; case 38: // up break; case 37: // left break; case 39: // right break; } }); And if it helps, here's the HTML div. I have a few of these on the page, and essentially, am trying to scroll to next one by pressing down arrow: <div class='screen-wrapper'> <div class='screen'> <div class="sections"> <ul> <li><img src="images/portfolio/sushii-1.png " /></li> <li><img src="images/portfolio/sushii-2.png" /></li> <li><img src="images/portfolio/sushii-3.png" /></li> </ul> </div> <div class="next"></div> <div class="prev"></div> </div> And also if it needed, I can provide a link where this is being used if it'll help someone get a better idea. edit And, i forgot to mention what the real question here is. The question/problem is that it won't scroll down past the first element, as seth mentioned.

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  • Hibernate : Opinions in Composite PK vs Surrogate PK

    - by Albert Kam
    As i understand it, whenever i use @Id and @GeneratedValue on a Long field inside JPA/Hibernate entity, i'm actually using a surrogate key, and i think this is a very nice way to define a primary key considering my not-so-good experiences in using composite primary keys, where : there are more than 1 business-value-columns combination that become a unique PK the composite pk values get duplicated across the table details cannot change the business value inside that composite PK I know hibernate can support both types of PK, but im left wondering by my previous chats with experienced colleagues where they said that composite PK is easier to deal with when doing complex SQL queries and stored procedure processes. They went on saying that when using surrogate keys will complicate things when doing joining and there are several condition when it's impossible to do some stuffs when using surrogate keys. Although im sorry i cant explain the detail here since i was not clear enough when they explain it. Maybe i'll put more details next time. Im currently trying to do a project, and want to try out surrogate keys, since it's not getting duplicated across tables, and we can change the business-column values. And when the need for some business value combination uniqueness, i can use something like : @Table(name="MY_TABLE", uniqueConstraints={ @UniqueConstraint(columnNames={"FIRST_NAME", "LAST_NAME"}) // name + lastName combination must be unique But im still in doubt because of the previous discussion about the composite key. Could you share your experiences in this matter ? Thank you !

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  • Reconnect to GPRS from J2ME

    - by ouzz
    Dear All, I have a little problem. I have developed a midlet application that call some webservices through internet. I'm using cell phones with GPRS connection. For some time it runs as I wanted, run the apps, call the webservices through the GPRS, it returns the result, call the webservices again, and so on. But say, I call the webservices and after the apps return the result I needed, I left it for a while. The next time I continue to access the webservices, the apps takes a while to connect through the GPRS. In nokia, it is marked with a G in a box. In SE it is marked with a glowing globe. This 'G' in the box or the glowing globe will appear after a while or won't appear at all, but the apps is still trying to connect to the internet. Does it come from my apps or it come from the cell phone? And could I know [or the apps knows] that at the moment the apps tries to connect the GPRS is ready? Thanks a lot for your responses...

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  • Ruby: add custom properties to built-in classes

    - by dreftymac
    Question: Using Ruby it is simple to add custom methods to existing classes, but how do you add custom properties? Here is an example of what I am trying to do: myarray = Array.new(); myarray.concat([1,2,3]); myarray._meta_ = Hash.new(); # obviously, this wont work myarray._meta_['createdby'] = 'dreftymac'; myarray._meta_['lastupdate'] = '1993-12-12'; ## desired result puts myarray._meta_['createdby']; #=> 'dreftymac' puts myarray.inspect() #=> [1,2,3] The goal is to construct the class definition in such a way that the stuff that does not work in the example above will work as expected. Update: (clarify question) One aspect that was left out of the original question: it is also a goal to add "default values" that would ordinarily be set-up in the initialize method of the class. Update: (why do this) Normally, it is very simple to just create a custom class that inherits from Array (or whatever built-in class you want to emulate). This question derives from some "testing-only" code and is not an attempt to ignore this generally acceptable approach.

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  • Ruby: add custom properties to built-in classes

    - by dreftymac
    Question: Using Ruby it is simple to add custom methods to existing classes, but how do you add custom properties? Here is an example of what I am trying to do: myarray = Array.new(); myarray.concat([1,2,3]); myarray._meta_ = Hash.new(); # obviously, this wont work myarray._meta_['createdby'] = 'dreftymac'; myarray._meta_['lastupdate'] = '1993-12-12'; ## desired result puts myarray._meta_['createdby']; #=> 'dreftymac' puts myarray.inspect() #=> [1,2,3] The goal is to construct the class definition in such a way that the stuff that does not work in the example above will work as expected. Update: (clarify question) One aspect that was left out of the original question: it is also a goal to add "default values" that would ordinarily be set-up in the initialize method of the class. Update: (why do this) Normally, it is very simple to just create a custom class that inherits from Array (or whatever built-in class you want to emulate). This question derives from some "testing-only" code and is not an attempt to ignore this generally acceptable approach.

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  • Seperation of game- and rendering logic

    - by Qua
    What is the best way to seperate rendering code from the actually game engine/logic code? And is it even a good idea to seperate those? Let's assume we have a game object called Knight. The Knight has to be rendered on the screen for the user to see. We're now left with two choices. Either we give the Knight a Render/Draw method that we can call, or we create a renderer class that takes care of rendering all knights. In the scenario where the two is seperated the Knight should the knight still contain all the information needed to render him, or should this be seperated as well? In the last project we created we decided to let all the information required to render an object be stored inside the object itself, but we had a seperate component to actually read those informations and render the objects. The object would contain information such as size, rotation, scale, and which animation was currently playing and based on this the renderer object would compose the screen. Frameworks such as XNA seem to think joining the object and rendering is a good idea, but we're afraid to get tied up to a specific rendering framework, whereas building a seperate rendering component gives us more freedom to change framework at any given time.

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  • Athentication Problem - not recognizing 'else' - Ruby on rails...

    - by bgadoci
    I can't seem to figure out what I am doing wrong here. I have implemented the Super Simple Authentication from Ryan Bates tutorial and while the login portion is functioning correctly, I can't get an error message and redirect to happen correctly for a bad login. Ryan Bates admits in his comments he left this out but can't seem to implement his recommendation. Basically what is happening is that when someone logs in correctly it works. When a bad password is entered it does the same redirect and flashes 'successfully logged in' thought they are not. The admin links do not show (which is correct and are the links protected by the <% if admin? %) but I need it to say 'failed login' and redirect to login path. Here is my code: SessionsController class SessionsController < ApplicationController def create if session[:password] = params[:password] flash[:notice] = 'Successfully logged in' redirect_to posts_path else flash[:notice] = "whoops" redirect_to login_path end end def destroy reset_session flash[:notice] = 'Successfully logged out' redirect_to posts_path end end ApplicationController class ApplicationController < ActionController::Base helper_method :admin? protected def authorize unless admin? flash[:error] = "unauthorized request" redirect_to posts_path false end end def admin? session[:password] == "string0826" end helper :all # include all helpers, all the time protect_from_forgery # See ActionController::RequestForgeryProtection for details # end

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  • Changing Positions of the Chart When Creating Multiple Charts Automatically via Vbasic in Excel 2007

    - by McVey
    I am creating a new chart for each row of data in an Excel spreadsheet. I have the Vbasic working properly, but I want to change the position of the chart on the sheet that is added for each row. Below is my code, what do I need to do to change the position of the chart on the page automatically? Ideally, I would like it to be in the upper left hand corner of each sheet. Sub DrawCharts() Dim Ws As Worksheet Dim NewWs As Worksheet Dim cht As Chart Dim LastRow As Long Dim CurrRow As Long Set Ws = ThisWorkbook.Worksheets("Sheet1") LastRow = Ws.Range("A65536").End(xlUp).Row For CurrRow = 2 To LastRow Set NewWs = ThisWorkbook.Worksheets.Add NewWs.Name = Ws.Range("A" & CurrRow).Value Set cht = ThisWorkbook.Charts.Add With cht .ChartType = xl3DColumnClustered .SeriesCollection.NewSeries .SeriesCollection(1).Values = "=" & Ws.Name & "!R" & CurrRow & "C3:R" & CurrRow & "C8" .SeriesCollection(1).Name = "=" & Ws.Name & "!R" & CurrRow & "C2" .SeriesCollection(1).XValues = "Sheet1!R1C3:R1C8" .Axes(xlValue).MinimumScale = 0 .Axes(xlValue).MaximumScale = 1 .Axes(xlValue).MajorUnit = 0.2 .SetElement (msoElementDataLabelShow) .SetElement (msoElementLegendNone) .Location Where:=xlLocationAsObject, Name:=NewWs.Name End With Next CurrRow End Sub Any help is appreciated.

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  • Strip parity bits in C from 8 bits of data followed by 1 parity bit

    - by dubnde
    I have a buffer of bits with 8 bits of data followed by 1 parity bit. This pattern repeats itself. The buffer is currently stored as an array of octets. Example (p are parity bits): 0001 0001 p000 0100 0p00 0001 00p01 1100 ... should become 0001 0001 0000 1000 0000 0100 0111 00 ... Basically, I need to strip of every ninth bit to just obtain the data bits. How can I achieve this? This is related to another question asked here sometime back. This is on a 32 bit machine so the solution to the related question may not be applicable. The maximum possible number of bits is 45 i.e. 5 data octets This is what I have tried so far. I have created a "boolean" array and added the bits into the array based on the the bitset of the octet. I then look at every ninth index of the array and through it away. Then move the remaining array down one index. Then I've got only the data bits left. I was thinking there may be better ways of doing this.

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  • WPF DataGrid binding difficulties

    - by Jasmin Pvvlovic
    This is the class: public class TrainingData { public string Training { get; set; } } And this is the rest of the code in MainWindow: Excel.Workbook xlWorkbook = xlApp.Workbooks.Open("D:/excel.xlsx"); Excel._Worksheet xlWorksheet = xlWorkbook.Sheets[1]; Excel.Range xlRange = xlWorksheet.UsedRange; List <TrainingData> tData= new List <TrainingData>(); int rowCount = xlRange.Rows.Count; int colCount = xlRange.Columns.Count; //int k = 0; for (int i = 1; i <= rowCount; i++) { tData.Add(new TrainingData() { Training = xlRange.Cells[i, 1].Value2.ToString() }); //MessageBox.Show(tData[k].Training); //k++; } Prikaz.ItemsSource = tData; DataGrid: <DataGrid AutoGenerateColumns="False" Height="120" HorizontalAlignment="Left" Margin="12,12,0,0" Name="Prikaz" VerticalAlignment="Top" Width="105" ItemsSource="{Binding}"> <DataGrid.Columns> <DataGridTextColumn Header="Header" /> </DataGrid.Columns> </DataGrid>` So, Prikaz is my DataGrid. tData is List of TrainingData objects. If I uncomment these three lines I can test if I have imported information from excel file correctly, and yes, that works just fine. So why am I getting empty DataGrid? It has right number of rows and only one column, that's ok, but there are no data in it. I used this line: Prikaz.ItemsSource = tData; to bind my objects list and DataGrid. Training is declared public so it should be present in DataGrid. What could be causing the problem?

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