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  • Problems with CGI wrapper for PHP

    - by user205878
    I'm having a bugger of a time with a CGI wrapper for PHP. I know very little about CGI and PHP as CGI. Here's what I know about the system: Solaris 10 on a 386 Suhosin PHP normally running as CGI, with cgiwrap (http://cgiwrap.sourceforge.net/). I am not able to find an example wrapper.cgi on the server to look at. Shared hosting (virtual host), so I don't have access to Apache config. But the admins are not helpful. Switching hosts is not an option. Options directive cannot be overridden in .htaccess (ExecCGI, for example). .htaccess: AddHandler php-handler .php Action php-handler "/bin/test.cgi" ~/public_html/bin/test.cgi: #!/usr/bin/sh # Without these 2 lines, I get an Internal Server Error echo "Content-type: text/html" echo "" exec "/path/to/php-cgi" 'foo.php'; /bin/foo.php: <?php echo "this is foo.php!"; Output of http://mysite.com/bin/test.cgi: X-Powered-By: PHP/5.2.11 Content-type: text/html echo "Content-type: text/html" echo "" exec "/path/to//php-cgi" 'foo.php'; Output of http:/ /mysite.com/anypage.php: X-Powered-By: PHP/5.2.11 Content-type: text/html echo "Content-type: text/html" echo "" exec "/path/to//php-cgi" 'foo.php'; The things I note are: PHP is being executed, as noted by the X-Powered-By ... header. The source of /bin/test.cgi is output in the results. No matter what I put as the second argument of exec, it isn't passed to the php binary. I've tried '-i' to get phpinfo, '-v' to get the version... When I execute test.cgi via the shell, I get the expected results (the argument is passed to php, and it is reflected in the output). Any ideas about how to get this to work? UPDATE It appears that the reason the source of the test.cgi was appearing was due to errors. Anytime fatal error occurred, either within the cgi itself or with the command being executed by exec, it would cause the source of the cgi to appear. Within test.cgi, I can get the proper output with exec "/path/to/php-cgi" -h (I get the same thing as I would from CLI).

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  • How to represent different entities that have identical behavior?

    - by Dominik
    I have several different entities in my domain model (animal species, let's say), which have a few properties each. The entities are readonly (they do not change state during the application lifetime) and they have identical behavior (the differ only by the values of properties). How to implement such entities in code? Unsuccessful attempts: Enums I tried an enum like this: enum Animals { Frog, Duck, Otter, Fish } And other pieces of code would switch on the enum. However, this leads to ugly switching code, scattering the logic around and problems with comboboxes. There's no pretty way to list all possible Animals. Serialization works great though. Subclasses I also thought about where each animal type is a subclass of a common base abstract class. The implementation of Swim() is the same for all Animals, though, so it makes little sense and serializability is a big issue now. Since we represent an animal type (species, if you will), there should be one instance of the subclass per application, which is hard and weird to maintain when we use serialization. public abstract class AnimalBase { string Name { get; set; } // user-readable double Weight { get; set; } Habitat Habitat { get; set; } public void Swim(); { /* swim implementation; the same for all animals but depends uses the value of Weight */ } } public class Otter: AnimalBase{ public Otter() { Name = "Otter"; Weight = 10; Habitat = "North America"; } } // ... and so on Just plain awful. Static fields This blog post gave me and idea for a solution where each option is a statically defined field inside the type, like this: public class Animal { public static readonly Animal Otter = new Animal { Name="Otter", Weight = 10, Habitat = "North America"} // the rest of the animals... public string Name { get; set; } // user-readable public double Weight { get; set; } public Habitat Habitat { get; set; } public void Swim(); } That would be great: you can use it like enums (AnimalType = Animal.Otter), you can easily add a static list of all defined animals, you have a sensible place where to implement Swim(). Immutability can be achieved by making property setters protected. There is a major problem, though: it breaks serializability. A serialized Animal would have to save all its properties and upon deserialization it would create a new instance of Animal, which is something I'd like to avoid. Is there an easy way to make the third attempt work? Any more suggestions for implementing such a model?

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  • "Alert" and "if" changes behaviour of dom copying from iframe to div

    - by lowkey
    Hi guys! Tried to make a little old school ajax (iframe-javascript) script. A bit of mootools is used for DOM navigation Description: HTML: 1 iframe called "buffer" 1 div called "display" JAVASCRIPT: (short: copy iframe content into a div on the page) 1) onLoad on iframe triggers handler(), a counter makes sure it only run once (this is because otherwise firefox will go into feedback loop. What i think happens: iframe on load handler() copyBuffer change src of iframe , and firefox takes that as an onload again) 2) copybuffer() is called, it sets src of iframe then copies iframe content into div, then erases iframe content THE CODE: count=0; function handler(){ if (count==0){ copyBuffer(); count++; } } function copyBuffer(){ $('buffer').set('src','http://www.somelink.com/'); if (window.frames['buffer'] && $('display') ) { $('display').innerHTML = window.frames['buffer'].document.body.innerHTML; window.frames['buffer'].document.body.innerHTML=""; } } problems: QUESTION 1) nothing happens, the content is not loaded into the div. But if i either: A) remove the counter and let the script run in a feedback loop: the content is suddenly copied into the div, but off course there is a feedback loop going on, you can see it keeps loading in the status bar. OR B) insert an alert in the copyBuffer function. The content is copied, without the feedback loop. why does this happen? QUESTION 2) The If wrapped around the copying code i got from a source on the internet. I am not sure what it does? If i remove it the code does not work in: Safari and Chrome. Many thanks in advance! UPDATE: Like the answers said i have created an event handler. They used jQuery, i have made one in mootools: window.addEvent('domready', function() { $('buffer').addEvent('load', function(){ $('display').set('html',window.frames['buffer'].document.body.innerHTML) window.frames['buffer'].document.body.innerHTML=""; }).set('src','somelink'); }); Bonus question: 3) Im new at stackoverflow (what an amazing place!), is it better if i make new threads for follow up questions?

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  • Stand-alone Java code formatter/beautifier/pretty printer?

    - by Greg Mattes
    I'm interested in learning about the available choices of high-quality, stand-alone source code formatters for Java. The formatter must be stand-alone, that is, it must support a "batch" mode that is decoupled from any particular development environment. Ideally it should be independent of any particular operating system as well. So, a built-in formatter for the IDE du jour is of little interest here (unless that IDE supports batch mode formatter invocation, perhaps from the command line). A formatter written in closed-source C/C++ that only runs on, say, Windows is not ideal, but is somewhat interesting. To be clear, a "formatter" (or "beautifier") is not the same as a "style checker." A formatter accepts source code as input, applies styling rules, and produces styled source code that is semantically equivalent to the original source code. A style checker also applies styling rules, but it simply reports rule violations without producing modified source code as output. So the picture looks like this: Formatter (produces modified source code that conforms to styling rules) Read Source Code → Apply Styling Rules → Write Styled Source Code Style Checker (does not produce modified source code) Read Source Code → Apply Styling Rules → Write Rule Violations Further Clarifications Solutions must be highly configurable. I want to be able to specify my own style, not simply select from a canned list. Also, I'm not looking for a general purpose pretty-printer written in Java that can pretty-print many things. I want to style Java code. I'm also not necessarily interested in a grand-unified formatter for many languages. I suppose it might be nice for a solution to have support for languages other than Java, but that is not a requirement. Furthermore, tools that only perform code highlighting are right out. I'm also not interested in a web service. I want a tool that I can run locally. Finally, solutions need not be restricted to open source, public domain, shareware, free software, commercial, or anything else. All forms of licensing are acceptable.

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  • PHP mysqli wrapper: passing by reference with __call() and call_user_func_array()

    - by Dave
    Hi everyone. I'm a long running fan of stackoverflow, first time poster. I'd love to see if someone can help me with this. Let me dig in with a little code, then I'll explain my problem. I have the following wrapper classes: class mysqli_wrapper { private static $mysqli_obj; function __construct() // Recycles the mysqli object { if (!isset(self::$mysqli_obj)) { self::$mysqli_obj = new mysqli(MYSQL_SERVER, MYSQL_USER, MYSQL_PASS, MYSQL_DBNAME); } } function __call($method, $args) { return call_user_func_array(array(self::$mysqli_obj, $method), $args); } function __get($para) { return self::$mysqli_obj->$para; } function prepare($query) // Overloaded, returns statement wrapper { return new mysqli_stmt_wrapper(self::$mysqli_obj, $query); } } class mysqli_stmt_wrapper { private $stmt_obj; function __construct($link, $query) { $this->stmt_obj = mysqli_prepare($link, $query); } function __call($method, $args) { return call_user_func_array(array($this->stmt_obj, $method), $args); } function __get($para) { return $this->stmt_obj->$para; } // Other methods will be added here } My problem is that when I call bind_result() on the mysqli_stmt_wrapper class, my variables don't seem to be passed by reference and nothing gets returned. To illustrate, if I run this section of code, I only get NULL's: $mysqli = new mysqli_wrapper; $stmt = $mysqli->prepare("SELECT cfg_key, cfg_value FROM config"); $stmt->execute(); $stmt->bind_result($cfg_key, $cfg_value); while ($stmt->fetch()) { var_dump($cfg_key); var_dump($cfg_value); } $stmt->close(); I also get a nice error from PHP which tells me: PHP Warning: Parameter 1 to mysqli_stmt::bind_result() expected to be a reference, value given in test.php on line 48 I've tried to overload the bind_param() function, but I can't figure out how to get a variable number of arguments by reference. func_get_args() doesn't seem to be able to help either. If I pass the variables by reference as in $stmt->bind_result(&$cfg_key, &$cfg_value) it should work, but this is deprecated behaviour and throws more errors. Does anyone have some ideas around this? Thanks so much for your time.

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  • WPF / Silverlight Binding when setting DataTemplate programically

    - by Daniel
    I have my little designer tool (my program). On the left side I have TreeView and on the right site I have Accordion. When I select a node I want to dynamically build Accordion Items based on Properties from DataContext of selected node. Selecting nodes works fine, and when I use this sample code for testing it works also. XAML code: <layoutToolkit:Accordion x:Name="accPanel" SelectionMode="ZeroOrMore" SelectionSequence="Simultaneous"> <layoutToolkit:AccordionItem Header="Controller Info"> <StackPanel Orientation="Horizontal" DataContext="{Binding}"> <TextBlock Text="Content:" /> <TextBlock Text="{Binding Path=Name}" /> </StackPanel> </layoutToolkit:AccordionItem> </layoutToolkit:Accordion> C# code: private void treeSceneNode_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e) { if (e.NewValue != e.OldValue) { if (e.NewValue is SceneNode) { accPanel.DataContext = e.NewValue; //e.NewValue is a class that contains Name property } } } But the problem occurs when I'm trying to achive this using DateTemplate and dynamically build AccordingItem, the Binding is not working: <layoutToolkit:Accordion x:Name="accPanel" SelectionMode="ZeroOrMore" SelectionSequence="Simultaneous" /> and DataTemplate in my ResourceDictionary <DataTemplate x:Key="dtSceneNodeContent"> <StackPanel Orientation="Horizontal" DataContext="{Binding}"> <TextBlock Text="Content:" /> <TextBlock Text="{Binding Path=Name}" /> </StackPanel> </DataTemplate> and C# code: private void treeSceneNode_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e) { if (e.NewValue != e.OldValue) { ResourceDictionary rd = new ResourceDictionary(); rd.Source = new Uri("/SilverGL.GUI;component/SilverGLDesignerResourceDictionary.xaml", UriKind.RelativeOrAbsolute); if (e.NewValue is SceneNode) { accPanel.DataContext = e.NewValue; AccordionItem accController = new AccordionItem(); accController.Header = "Controller Info"; accController.ContentTemplate = rd["dtSceneNodeContent"] as DataTemplate; accPanel.Items.Add(accController); } else { // Other type of node } } } I really need help with this issue. Thanks for any support.

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  • Silverlight ControlTemplate and F#

    - by akaphenom
    Has anybody had any success incorporating a Silverlight ControlTemplate into an F# Silverlight application. I am trying to add transitions to the Navgiation.Frame element and following along on with a C# example: http://www.davidpoll.com/2009/07/19/silverlight-3-navigation-adding-transitions-to-the-frame-control The downloaded source uses the MSBUILD:Compile option on the template XAML and the file is included as a "Page"... ILDASM doesn't show any object created for the XAML; In my project I incldued it as a "Resource" (same as I have done for my pages) and referenced it in app.xaml: <Application xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" x:Class="Module1.MyApp"> <Application.Resources> <ResourceDictionary> <ResourceDictionary.MergedDictionaries> <ResourceDictionary Source="/FSSilverlightApp;component/TransitioningFrame.xaml"/> </ResourceDictionary.MergedDictionaries> </ResourceDictionary> </Application.Resources> </Application> the TransitioningFrame.xaml is as follows: <ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:navigation="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Navigation" xmlns:toolkit="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Layout.Toolkit"> <ControlTemplate x:Key="TransitioningFrame" TargetType="navigation:Frame"> <Border Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"> <toolkit:TransitioningContentControl Content="{TemplateBinding Content}" Cursor="{TemplateBinding Cursor}" Margin="{TemplateBinding Padding}" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}" Transition="DefaultTransition" /> </Border> </ControlTemplate> </ResourceDictionary> My page objects all load their respective xaml with the follwoing code: type Page1() as this = inherit UriUserControl("/FSSilverlightApp;component/Page1.xaml") do Application.LoadComponent(this, base.uri) and somewhere in app startup: let p1 = new Page1() I donot have a comparable piece for the ControlTemplate - though I was hoping the application object and App.xaml would pull it in magically (as an aside, the reliance on this magic has made setting up a 100% f# silverlight application rather tricky - as nearly all the published articles I find are based around wizards and short cuts - very little on the acual plumbing - ugh). Any advice or thougts on the subject are appreciated.

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  • Controling virtualbox internet access?

    - by HandyGandy
    I am finally going through the process of moving my XP into a vbox (host linux). The thing is that I am migrating a virtually clean install. So aside from the occasional antivirus scan, I want to make sure that my XP is not sending malware data (keystoke.logs, spam etc. ) out silently ( and thus having picked up some virus ). To that end I want to limit XP to contacting my LAN and a few internet sites. ( mainly sites that require proprietary windows only software to access, AV sites and Windows update ). I want XP to only access preapproved addresses. If it is trying to contact a nonapproved address, I want it somehow logged and access restricted until I allow access. I also don't want to have to decide whether to allow access to a site at my leisure. To keeps things clear let me give an example: I start my vbox/XP ( which I call MYXP) running on my linux box ( called MYLINUX connecting to the net through a linksys wrt54g ) and connects via samba to my LAN ( since my LAN seems to be possessed of every evil thing, it's address is 192.168.666. ). At the moment my configuration is set so that I allow MYXP to access 192.168.666 and www.MYANTIVIRUS_UPDATES.com and www.MS_UPDATES.com. Then on the VM I start a program which tries to make a connection to www.playmygame.com . www.playmygame.com is on my preapproved list so the connection goes through. Later I check attempted accesses and discover that it also tried to connect to www.mygame_high_scores.com I figure this is OK so I add www.mygame_high_scores.com to my approved list. Later, I again check address and discover that my VM/XP tried to access www.mygame_steals_your_identity.com. I do some checking and discover the address is registered to someone in Kiev, Nigeria. Since this doesn't sound kosher to me, I replace the MYXP VM with one that was backed up before I installed mygame. I remove www.playmygame.com and www.mygame_high_scores.com from my access list for MYXP. It should acomplish this with little overheard. When I am not running the VM ideally it should not have any overhead. Suggestions?

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  • Heroku Push Problem part 2 - Postgresql - PGError Relations does not exist - Ruby on Rails

    - by bgadoci
    Ok so got through my last problem with the difference between Postgresql and SQLite and seems like Heroku is telling me I have another one. I am new to ruby and rails so a lot of this stuff I can't decipher at first. Looking for a little direction here. The error message and PostsController Index are below. I checked my routes.rb file and all seems well there but I could be missing something. I will post if you need. Processing PostsController#index (for 99.7.50.140 at 2010-04-23 15:19:22) [GET] ActiveRecord::StatementInvalid (PGError: ERROR: relation "tags" does not exist : SELECT a.attname, format_type(a.atttypid, a.atttypmod), d.adsrc, a.attnotnull FROM pg_attribute a LEFT JOIN pg_attrdef d ON a.attrelid = d.adrelid AND a.attnum = d.adnum WHERE a.attrelid = '"tags"'::regclass AND a.attnum > 0 AND NOT a.attisdropped ORDER BY a.attnum ): PostsController#index def index @tag_counts = Tag.count(:group => :tag_name, :order => 'count_all DESC', :limit => 20) conditions, joins = {}, :votes @ugtag_counts = Ugtag.count(:group => :ugctag_name, :order => 'count_all DESC', :limit => 20) conditions, joins = {}, :votes @vote_counts = Vote.count(:group => :post_title, :order => 'count_all DESC', :limit => 20) conditions, joins = {}, :votes unless(params[:tag_name] || "").empty? conditions = ["tags.tag_name = ? ", params[:tag_name]] joins = [:tags, :votes] end @posts=Post.paginate( :select => "posts.*, count(*) as vote_total", :joins => joins, :conditions=> conditions, :group => "votes.post_id, posts.id ", :order => "created_at DESC", :page => params[:page], :per_page => 5) @popular_posts=Post.paginate( :select => "posts.*, count(*) as vote_total", :joins => joins, :conditions=> conditions, :group => "votes.post_id, posts.id", :order => "vote_total DESC", :page => params[:page], :per_page => 3) respond_to do |format| format.html # index.html.erb format.xml { render :xml => @posts } format.json { render :json => @posts } format.atom end end

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  • Odd ActiveRecord model dynamic initialization bug in production

    - by qfinder
    I've got an ActiveRecord (2.3.5) model that occasionally exhibits incorrect behavior that appears to be related to a problem in its dynamic initialization. Here's the code: class Widget < ActiveRecord::Base extend ActiveSupport::Memoizable serialize :settings VALID_SETTINGS = %w(show_on_sale show_upcoming show_current show_past) VALID_SETTINGS.each do |setting| class_eval %{ def #{setting}=(val); self.settings[:#{setting}] = (val == "1"); end def #{setting}; self.settings[:#{setting}]; end } end def initialize_settings self.settings ||= { :show_on_sale => true, :show_upcoming => true } end after_initialize :initialize_settings # All the other stuff the model does end The idea was to use a single record field (settings) to persist a bunch of configuration data for this object, but allow all the settings to seamlessly work with form helpers and the like. (Why this approach makes sense here is a little out of scope, but let's assume that it does.) Net-net, Widget should end up with instance methods (eg #show_on_sale= #show_on_sale) for all the entires in the VALID_SETTINGS array. Any default values should be specified in initialize_settings. And indeed this works, mostly. In dev and staging, no problems at all. But in production, the app sometimes ends up in a state where a) any writes to the dynamically generated setters fail and b) none of the default values appear to be set - although my leading theory is that the dynamically generated reader methods are just broken. The code, db, and environment is otherwise identical between the three. A typical error message / backtrace on the fail looks like: IndexError: index 141145 out of string (eval):2:in []=' (eval):2:inshow_on_sale=' [GEM_ROOT]/gems/activerecord-2.3.5/lib/active_record/base.rb:2746:in send' [GEM_ROOT]/gems/activerecord-2.3.5/lib/active_record/base.rb:2746:inattributes=' [GEM_ROOT]/gems/activerecord-2.3.5/lib/active_record/base.rb:2742:in each' [GEM_ROOT]/gems/activerecord-2.3.5/lib/active_record/base.rb:2742:inattributes=' [GEM_ROOT]/gems/activerecord-2.3.5/lib/active_record/base.rb:2634:in `update_attributes!' ...(then controller and all the way down) Ideas or theories as to what might be going on? My leading theory is that something is going wrong in instance initialization wherein the class instance variable settings is ending up as a string rather than a hash. This explains both the above setter failure (:show_on_sale is being used to index into the string) and the fact that getters don't work (an out of bounds [] call on a string just returns nil). But then how and why might settings occasionally end up as a string rather than hash?

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  • Populating a UL with Jquery

    - by RachelGatlin
    Hi Guys, I'm a little bit stumped with this UL I'm building. I've been able to populate the list no problem but it's all messed up when it comes to formatting. Here's my script: $.ajax({ type: "GET", url: "/shop/assets/xml/tonneau_makes.xml", dataType: "xml", success: function(xml) { var selectInfo = $("li.selectMake"); $(xml).find('option').each(function(){ var make = $(this).attr('make'); $("li.selectMake").before("<li>"+make+"</li>"); }); } }); It's working beautifully. however when I go to look at it on my page and view the selection source it looks like this: <ul id="MakeList"> <li>CHEVROLET</li> <li>VINTAGE CHEVY</li> <li>DODGE</li> <li>VINTAGE FORD</li> <li>FORD</li> <li>HONDA</li> <li>HUMMER</li> <li>ISUZU</li> <li>LINCOLN</li> <li>MAZDA</li> <li>MITSUBISHI</li> <li>NISSAN</li> <li>SUZUKI</li> <li>TOYOTA</li> <li class="selectMake"></li> So I guess it is working, but it's not formatting the way I want it to. I want it to stop at Honda and form a new list. Right now it's extending beyond my div. My html is set up like this: <ul id="MakeList"> <li class="selectMake"></li> </ul> It's just an empty ul and li (note, all li's are supposed to have that class) So not only do I need to figure out what I'm doing wrong, but I'm not sure how to get it to do what I want. I hope that all made sense! Thanks everybody!

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  • MBR Booting from DOS

    - by eflukx
    For a project I would like to invoke the MBR on the first harddisk directly from DOS. I've written a small assembler program that loads the MBR in memory at 0:7c00h an does a far jump to it. I've put my util on a bootable floppy. The disk (HD0, 0x80) i'm trying to boot has a TrueCrypt boot loader on it. It shows up the TrueCrypt screen, but after typing in the password it crashes the system. When I run my little utlility (w00t.com) on a normal WinXP machine it seams to crash immedealty. Apparently I'm forgetting some crucial stuff the BIOS normally does, my guess is it's something trivial. Can someone with better bare-metal DOS and BIOS experience help me out? Heres my code: .MODEL tiny .386 _TEXT SEGMENT USE16 INCLUDE BootDefs.i ORG 100h start: ; http://vxheavens.com/lib/vbw05.html ; Before DOS has booted the BIOS stores the amount of usable lower memory ; in a word located at 0:413h in memory. We going to erase this value because ; we have booted dos before loading the bootsector, and dos is fat (and ugly). ; fake free memory ;push ds ;push 0 ;pop ds ;mov ax, TC_BOOT_LOADER_SEGMENT / 1024 * 16 + TC_BOOT_MEMORY_REQUIRED ;mov word ptr ds:[413h], ax ;ax = memory in K ;pop ds ;lea si, memory_patched_msg ;call print ;mov ax, cs mov ax, 0 mov es, ax ; read first sector to es:7c00h (== cs:7c00) mov dl, 80h mov cl, 1 mov al, 1 mov bx, 7c00h ;load sector to es:bx call read_sectors lea si, mbr_loaded_msg call print lea si, jmp_to_mbr_msg call print ;Set BIOS default values in environment cli mov dl, 80h ;(drive C) xor ax, ax mov ds, ax mov es, ax mov ss, ax mov sp, 0ffffh sti push es push 7c00h retf ;Jump to MBR code at 0:7c00h ; Print string print: xor bx, bx mov ah, 0eh cld @@: lodsb test al, al jz print_end int 10h jmp @B print_end: ret ; Read sectors of the first cylinder read_sectors: mov ch, 0 ; Cylinder mov dh, 0 ; Head ; DL = drive number passed from BIOS mov ah, 2 int 13h jnc read_ok lea si, disk_error_msg call print read_ok: ret memory_patched_msg db 'Memory patched', 13, 10, 7, 0 mbr_loaded_msg db 'MBR loaded', 13, 10, 7, 0 jmp_to_mbr_msg db 'Jumping to MBR code', 13, 10, 7, 0 disk_error_msg db 'Disk error', 13, 10, 7, 0 _TEXT ENDS END start

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  • EntityManagerFactory error on Websphere

    - by neverland
    I have a very weird problem. Have an application using Hibernate and spring.I have an entitymanger defined which uses a JNDI lookup .It looks something like this <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> <property name="dataSource" ref="dataSource" /> <property name="persistenceUnitName" value="ConfigAPPPersist" /> <property name="jpaVendorAdapter"> <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"> <property name="showSql" value="true" /> <property name="generateDdl" value="false" /> <property name="databasePlatform" value="org.hibernate.dialect.Oracle9Dialect" /> </bean> </property> </bean> <bean id="dataSource" class="org.springframework.jdbc.datasource.WebSphereDataSourceAdapter"> <property name="targetDataSource"> <bean class="org.springframework.jndi.JndiObjectFactoryBean"> <property name="jndiName" value="jdbc/pmp" /> </bean> </property> </bean> This application runs fine in DEV. But when we move to higher envs the team that deploys this application does it successfully initially but after a few restarts of the application the entitymanager starts giving this problem Caused by: javax.persistence.PersistenceException: [PersistenceUnit: ConfigAPPPersist] Unable to build EntityManagerFactory at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:677) at org.hibernate.ejb.HibernatePersistence.createContainerEntityManagerFactory(HibernatePersistence.java:132) at org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean.createNativeEntityManagerFactory(LocalContainerEntityManagerFactoryBean.java:224) at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:291) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1368) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1334) ... 32 more Caused by: org.hibernate.MappingException: **property mapping has wrong number of columns**: com.***.***.jpa.marketing.entity.MarketBrands.$performasure_j2eeInfo type: object Now you would say this is pretty obvious the entity MarketBrands is incorrect. But its not it maps to the table just fine. And the same code works on DEV. Also the jndi cannot be incorrect since it deploys and works fine initially but throws uo this error after a restart. This is weird and not very logical. But if someone has faced this or has any idea on what might be causing this Please!! help The persistence.xml for the persitence unit has very little <?xml version="1.0" encoding="UTF-8"?> <persistence xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" version="1.0"> <persistence-unit name="ConfigAPPPersist"> <!-- commented code --> </persistence-unit> </persistence>

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  • How to programmatically bind to a Core Data model?

    - by Dave Gallagher
    Hello. I have a Core Data model, and was wondering if you know how to create a binding to an Entity, programmatically? Normally you use bind:toObject:withKeyPath:options: to create a binding. But I'm having a little difficulty getting this to work with Core Data, and couldn't find anything in Apple's docs regarding doing this programmatically. The Core Data model is simple: An Entity called Book An Attribute of Book called author (NSString) I have an object called BookController. It looks like so: @interface BookController : NSObject { NSString *anAuthor; } @property (nonatomic, retain) NSString *anAuthor; // @synthesize anAuthor; inside @implementation I'd like to bind anAuthor inside BookController, to author inside a Book entity. This is how I'm attempting to wrongly do it (it partially works): // A custom class I made, providing an interface to the Core Data database CoreData *db = [[CoreData alloc] init]; // Creating a Book entity, saving it [db addMocObject:@"Book"]; [db saveMoc]; // Fetching the Book entity we just created NSArray *books = [db fetchObjectsForEntity:@"Book" withPredicate:nil withSortDescriptors:nil]; NSManagedObject *book = [books objectAtIndex:0]; // Creating the binding BookController *bookController = [[BookController alloc] init]; [bookController bind:@"anAuthor" toObject:book withKeyPath:@"author" options:nil]; // Manipulating the binding [bookController setAnAuthor:@"Bill Gates"]; Now, when updating from the perspective of bookController, things don't work quite right: // Testing the binding from the bookController's perspective [bookController setAnAuthor:@"Bill Gates"]; // Prints: "bookController's anAuthor: Bill Gates" NSLog(@"bookController's anAuthor: %@", [bookController anAuthor]); // OK! // ERROR HERE - Prints: "bookController's anAuthor: (null)" NSLog(@"Book's author: %@", [book valueForKey:@"author"]); // DOES NOT WORK! :( When updating from the perspective of the Book entity, things work fine: // ------------------------------ // Testing the binding from the Book's (Entity) perspective (this works perfect) [book setValue:@"Steve Jobs" forKey:@"author"]; // Prints: "bookController's anAuthor: Steve Jobs" NSLog(@"bookController's anAuthor: %@", [bookController anAuthor]); // OK! // Prints: "bookController's anAuthor: Steve Jobs" NSLog(@"Book's author: %@", [book valueForKey:@"author"]); // OK! It appears that the binding is partially working. I can update it on the side of the Model and it propagates up to the Controller via KVO, but if I update it on the side of the Controller, it doesn't trickle down to the Model via KVC. Any idea on what I'm doing wrong? Thanks so much for looking! :)

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  • Is the Scala 2.8 collections library a case of "the longest suicide note in history" ?

    - by oxbow_lakes
    First note the inflammatory subject title is a quotation made about the manifesto of a UK political party in the early 1980s. This question is subjective but it is a genuine question, I've made it CW and I'd like some opinions on the matter. Despite whatever my wife and coworkers keep telling me, I don't think I'm an idiot: I have a good degree in mathematics from the University of Oxford and I've been programming commercially for almost 12 years and in Scala for about a year (also commercially). I have just started to look at the Scala collections library re-implementation which is coming in the imminent 2.8 release. Those familiar with the library from 2.7 will notice that the library, from a usage perspective, has changed little. For example... > List("Paris", "London").map(_.length) res0: List[Int] List(5, 6) ...would work in either versions. The library is eminently useable: in fact it's fantastic. However, those previously unfamiliar with Scala and poking around to get a feel for the language now have to make sense of method signatures like: def map[B, That](f: A => B)(implicit bf: CanBuildFrom[Repr, B, That]): That For such simple functionality, this is a daunting signature and one which I find myself struggling to understand. Not that I think Scala was ever likely to be the next Java (or /C/C++/C#) - I don't believe its creators were aiming it at that market - but I think it is/was certainly feasible for Scala to become the next Ruby or Python (i.e. to gain a significant commercial user-base) Is this going to put people off coming to Scala? Is this going to give Scala a bad name in the commercial world as an academic plaything that only dedicated PhD students can understand? Are CTOs and heads of software going to get scared off? Was the library re-design a sensible idea? If you're using Scala commercially, are you worried about this? Are you planning to adopt 2.8 immediately or wait to see what happens? Steve Yegge once attacked Scala (mistakenly in my opinion) for what he saw as its overcomplicated type-system. I worry that someone is going to have a field day spreading fud with this API (similarly to how Josh Bloch scared the JCP out of adding closures to Java). Note - I should be clear that, whilst I believe that Josh Bloch was influential in the rejection of the BGGA closures proposal, I don't ascribe this to anything other than his honestly-held beliefs that the proposal represented a mistake.

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  • Volunteer for a potential employer?

    - by EoRaptor013
    I've been looking for work since March, and haven't had much luck. Recently, however, I interviewed with a small company near my home for a C#, .NET, SQL development position. I hit it off very well with the hiring manager during the phone screen, and even more so during the face to face. Unfortunately, I failed the practical test: wiring up a web form, creating a couple of SQL stored procedures, saving new data with validation, and creating a minimal search screen. I knew what I was doing, but I was too slow to meet their standards as all the work needed to be done within an hour. Nevertheless, I really liked the place, the environment, the people who I would have been working with, and the boss. (I gave the company an 11 on Joel's 12 point scale.) So, the obvious next step was to scrape the rust off. I've been trying to create little projects for myself, but I don't know that I've been effective in getting any faster. What with all that goes into creating a project, I'm not heads-down coding as much as I think I need. Now, with all that introduction, here's the question. I have been thinking about calling the hiring manager at that place, and asking him to let me volunteer for three or four weeks, with no strings attached. I think it would benefit me, and wouldn't cost him anything (as long as I didn't slow the existing people down!). At the end of that period, he might, or might not, be inclined to hire me, but even if not, I would have had as much as 160 hours of in the trenches development. Maybe not all shiny, but no more rust, I would think. Does this plan make any sense at all? I certainly don't want to sound desperate (although, I'm not far from being there), and I very much need the tuneup, lube, and change the oil. What's the downside, if any, to me doing this? Do any of you see red flags going up—either from the prerspective of the hiring manager, or from the perspective of a developer?

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  • How to make Flash 'play well with others'?

    - by Sensei James
    What up fam. So this isn't a question asking about memory management schemes; for those of you who may not know, the Flash Virtual Machine relies on garbage collection by using reference counting and mark and sweep (for good coverage of these topics, check out Grant Skinner's article and presentation). And yes, Flash also provides the "delete" operator, which can (unfortunately only) be used to remove the properties of dynamic objects. What I want to know is how to make it so that Flash programs don't continue to consume CPU and memory while running in the background (save loading content or communicating remotely, for example). The motivation for this question comes in part from Apple's ban on cross compiled applications (in its SDK 4) on the grounds that they do not behave as predicted with the multitasking feature central to iPhone OS 4. My intention is not only to make Flash programs that will 'pass muster' as far as multitasking in iPhone OS 4, but also to simply make better (behaving) Flash programs. Put another way, how might a Flash application mimic the multitasking feature of iPhone OS 4? Does the Flash API provide the means for a developer to put their applications to 'sleep' while other programs run, and then to 'awaken' them just as quickly? In our own program, we might do something as crude as detecting when the user has been idle (no mouse motion or key press) for (say) four seconds: var idle_id:uint = setInterval(4000, pause_program); var current_movie_clip:MovieClip; var current_frame:uint; ... // on Mouse move or key press... clearInterval(idle_id); idle_id = setInterval(4000, pause_program); ... function pause_program():void { current_movie_clip = event.target as MovieClip; current_frame = current_movie_clip.currentFrame; MovieClip(root).gotoAndStop("program_pause_screen"); } (on the program pause screen) resume_button.addEventListener(MouseEvent.CLICK, resume_program); function resume_program(event:MouseEvent) { current_movie_clip.gotoAndPlay(current_frame); } If that's the right idea, what's the best way to detect that an application should be shelved? And, more importantly, is it possible for Flash Player to detect that some of its running programs are idle, and to similarly shelve them until the user performs an action to resume them? (Please feel free to answer as much or as little of the many questions I've posed.)

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  • css formatting problems

    - by Davey
    So I wanted to mess around with Sass so I created this tiny incredibly simple little page. For reasons unknown to me when I add a top-margin to #content it effects my wrapper div instead. Any information as to why this is happening would be greatly appreciated. Thanks! Here is the page live: http://cheapramen.com/omg/ html: <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <link rel="stylesheet" href="stylesheets/screen.css" type="text/css" media="screen" /> <title>YO</title> </head> <body> <div id="wrapper"> <div id="content"> <div class="dog"> Bury me with my money </div> </div> </div> </body> </html> Sass html body background-color: #000 padding: 0 margin: 0 height: 100% #wrapper background-color: #fff width: 900px height: 700px margin: 0 auto #content width: 500px margin: 150px 0 0 50px .dog color: #FF3836 font-size: 25px text-shadow: 2px 2px 2px #000 width: 500px height: 500px -moz-border-radius: 5px -webkit-border-radius: 5px border: 18px solid #FF3836 Css that the Sass spits out html body { background-color: #000; padding: 0; margin: 0; height: 100%; } #wrapper { background-color: #fff; width: 900px; height: 700px; margin: 0 auto; } #content { width: 500px; margin: 150px 0 0 50px; } .dog { color: #FF3836; font-size: 25px; text-shadow: 2px 2px 2px #000; width: 500px; height: 500px; -moz-border-radius: 5px; -webkit-border-radius: 5px; border: 18px solid #FF3836; }

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  • Efficiency of data structures in C99 (possibly affected by endianness)

    - by Ninefingers
    Hi All, I have a couple of questions that are all inter-related. Basically, in the algorithm I am implementing a word w is defined as four bytes, so it can be contained whole in a uint32_t. However, during the operation of the algorithm I often need to access the various parts of the word. Now, I can do this in two ways: uint32_t w = 0x11223344; uint8_t a = (w & 0xff000000) >> 24; uint8_t b = (w & 0x00ff0000) >> 16; uint8_t b = (w & 0x0000ff00) >> 8; uint8_t d = (w & 0x000000ff); However, part of me thinks that isn't particularly efficient. I thought a better way would be to use union representation like so: typedef union { struct { uint8_t d; uint8_t c; uint8_t b; uint8_t a; }; uint32_t n; } word32; Using this method I can assign word32 w = 0x11223344; then I can access the various parts as I require (w.a=11 in little endian). However, at this stage I come up against endianness issues, namely, in big endian systems my struct is defined incorrectly so I need to re-order the word prior to it being passed in. This I can do without too much difficulty. My question is, then, is the first part (various bitwise ands and shifts) efficient compared to the implementation using a union? Is there any difference between the two generally? Which way should I go on a modern, x86_64 processor? Is endianness just a red herring here? I could inspect the assembly output of course, but my knowledge of compilers is not brilliant. I would have thought a union would be more efficient as it would essentially convert to memory offsets, like so: mov eax, [r9+8] Would a compiler realise that is what happening in the bit-shift case above? If it matters, I'm using C99, specifically my compiler is clang (llvm). Thanks in advance.

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  • Is this a situation where Qt Model/View architecture is not useful?

    - by csmithmaui
    Hi, I am writing a GUI based application where I read a string of values from serial port every few seconds and I need to display most of the values in some type graphical indicator(I was thinking of QprogressBar maybe) that displays the range and the value. Some of the other data that I am parsing from the string are the date and fault codes. Also, the data is hierarchical. I wanted to use the model/view architecture of Qt because I have been interested in MVC stuff for a while but have never quite wrapped my brain around how to implement it very well. As of now, I have subclassed QAbstractItemModel and in the model I read the serial port and wrap the items parsed from the string in a Tree data structure. I can view all of the data in a QtreeView with no issues. I have also began to subclass QAbstractItemView to build my custom view with all of the Graphical Indicators and such. This is where I am getting stuck. It seems to me that in order for me to design a view that knows how to display my custom model the view needs to know exactly how all of the data in the model is organized. Doesn't that defeat the purpose of Model/View? The QTreeView I tested the model with is basically just displaying the model as it is setup in the Tree structure but I don't want to do that because the data is not all of the same type. Is the type of data or the way you would like to present it to the user a determining factor in whether or not you should use this architecture? I always assumed it was just always better to design in an MVC style. It seems to me like it might have been better to just subclass QWidget and then read in from the serial port and update all of subwidgets(graphical indicators, labels, etc...) from the subclass. Essentially, do everything in one class. Does anybody understand this issue that can explain to me either what I am missing or why I shouldn't be doing it this way. As of now I am a little confused. Thanks so much for any help!

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  • Yii - Custom GridView with Multiple Tables

    - by savinger
    So, I've extended GridView to include an Advanced Search feature tailored to the needs of my organization. Filter - lets you show/hide columns in the table, and you can also reorder columns by dragging the little drag icon to the left of each item. Sort - Allows for the selection of multiple columns, specify Ascending or Descending. Search - Select your column and insert search parameters. Operators tailored to data type of selected column. Version 1 works, albeit slowly. Basically, I had my hands in the inner workings of CGridView, where I snatch the results from the DataProvider and do the searching and sorting in PHP before rendering the table contents. Now writing Version 2, where I aim to focus on clever CDbCriteria creation, allowing MySQL to do the heavy lifting so it will run quicker. The implementation is trivial when dealing with a single database table. The difficulty arises when I'm dealing with 2 or more tables... For example, if the user intends to search on a field that is a STAT relation, I need that relation to be present in my query. Here's the question. How do I assure that Yii includes all with relations in my query so that I include comparisons? I've included all my relations with my criteria in the model's search function and I've tried CDbCriteria's together ... public function search() { $criteria=new CDbCriteria; $criteria->compare('id', $this->id); $criteria->compare( ... ... $criteria->with = array('relation1','relation2','relation3'); $criteria->together = true; return new CActiveDataProvider( get_class($this), array( 'criteria'=>$criteria, 'pagination' => array('pageSize' => 50) ));} But I still get errors like this... CDbCommand failed to execute the SQL statement: SQLSTATE[42S22]: Column not found: 1054 Unknown column 't.relation3' in 'where clause'. The SQL statement executed was: SELECT COUNT(DISTINCT `t`.`id`) FROM `table` `t` LEFT OUTER JOIN `relation_table` `relation0` ON (`t`.`id`=`relation0`.`id`) LEFT OUTER JOIN `relation_table` `relation1` ON (`t`.`id`=`relation1`.`id`) WHERE (`t`.`relation3` < 1234567890) Where relation0 and relation1 are BELONGS_TO relations, but any STAT relations are missing. Furthermore, why is the query a SELECT COUNT(DISTINCT 't'.'id') ?

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  • Auto update the content in ASP.NET

    - by Zerotoinfinite
    I have to design a website where user can update their status, just like facebook and twitter and other social networking sites. Now my requirement is to refresh the feed with new user updates. Ex: when the new status comes facebook automatically add that on the top of the feed. on the other hand twitter shows the number of updates which is ready to be load. both ways are acceptable to me Now, I have to decide what is the best way to achieve this functionality. I am open to use ASP.NET. So I am confused that regular repeater control with timer and auto refresh or any other way? (I am wondering that if I set repeater for auto update and meanwhile if user is performing some action on any status it will lost). or do I need to change my framework from ASP.NET to ASP.NET MVC (I am little afraid with MVC as I have very less knowledge regarding it and I know it has a learning curve to master ajax/Jquery things) Any suggestion how I can I achieve it in a better and feasible way? EDIT1 I am not looking for a code but I want advice to achieve this. Supporting URL's would be appreciated. EDIT2 I am open to JQuery which can regularly check the database and fill the section. But my concern is this that if user is updating any comment and want to load/feed is automatically generated. his textbox text shouldn't be disappear (just like facebook, twitter or Linkedin) EDIT3 I have seen that on Stack overflow when any other user has modified the question/answer, I got notification like this question/answer is modified. and when I clicked on that notification only that section got reloaded. I am curious to know how to achieve this functionality. So that when user is commenting on a status/post and if meanwhile someone has updated the content then it would show the other user comment. Edit4 Could someone please recommend me an example of ASP.NET MVC 3+ which can do similar kind of activity (i.e. one input box and once user insert an text it will add the item in the list (with JQuery).

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  • C#: BackgroundWorker cloning resources?

    - by Dav
    The problem I've been struggling with this partiular problem for two days now and just run out of ideas. A little... background: we have a WinForms app that needs to access a database, construct a list of related in-memory objects from that data, and then display on a DataGridView. Important point is that we first populate an app-wide cache (List), and then create a mirror of the cache local to the form on which the DGV lives (using List constructor param). Because fetching the data takes a good few seconds (DB sits on a LAN server) to load, we decided to use a BackgroundWorker, and only refresh the DGV once the data is loaded. However, it seems that doing the loading via a BGW results in some memory leak... or an error on my part. When loaded using a blocking method call, the app consumes about 30MB of RAM; with a BGW this jumps to 80MB! While it may not seem as much anyway, our clients are not too happy about it. Relevant code Form private void MyForm_Load(object sender, EventArgs e) { MyRepository.Instance.FinishedEvent += RefreshCache; } private void RefreshCache(object sender, EventArgs e) { dgvProducts.DataSource = new List<MyDataObj>(MyRepository.Products); } Repository private static List<MyDataObj> Products { get; set; } public event EventHandler ProductsLoaded; public void GetProductsSync() { List<MyDataObj> p; using (MyL2SDb db = new MyL2SDb(MyConfig.ConnectionString)) { p = db.PRODUCTS .Select(p => new MyDataObj {Id = p.ID, Description = p.DESCR}) .ToList(); } Products = p; // tell the form to refresh UI if (ProductsLoaded != null) ProductsLoaded(this, null); } public void GetProductsAsync() { using (BackgroundWorker myWorker = new BackgroundWorker()) { myWorker.DoWork += delegate { List<MyDataObj> p; using (MyL2SDb db = new MyL2SDb(MyConfig.ConnectionString)) { p = db.PRODUCTS .Select(p => new MyDataObj {Id = p.ID, Description = p.DESCR}) .ToList(); } Products = p; }; // tell the form to refresh UI when finished myWorker.RunWorkerCompleted += GetProductsCompleted; myWorker.RunWorkerAsync(); } } private void GetProductsCompleted(object sender, RunWorkerCompletedEventArgs e) { if (ProductsLoaded != null) ProductsLoaded(this, null); } End! GetProductsSync or GetProductsAsync are called on the main thread, not shown above. Could it be that the GarbageCollector just gets lost with two threads? Or is it the task manager that shows incorrect values? Will be greateful for any responses, suggestions, criticism.

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  • C# - How to override GetHashCode with Lists in object

    - by Christian
    Hi, I am trying to create a "KeySet" to modify UIElement behaviour. The idea is to create a special function if, eg. the user clicks on an element while holding a. Or ctrl+a. My approach so far, first lets create a container for all possible modifiers. If I would simply allow a single key, it would be no problem. I could use a simple Dictionary, with Dictionary<Keys, Action> _specialActionList If the dictionary is empty, use the default action. If there are entries, check what action to use depending on current pressed keys And if I wasn't greedy, that would be it... Now of course, I want more. I want to allow multiple keys or modifiers. So I created a wrapper class, wich can be used as Key to my dictionary. There is an obvious problem when using a more complex class. Currently two different instances would create two different key, and thereby he would never find my function (see code to understand, really obvious) Now I checked this post: http://stackoverflow.com/questions/638761/c-gethashcode-override-of-object-containing-generic-array which helped a little. But my question is, is my basic design for the class ok. Should I use a hashset to store the modifier and normal keyboardkeys (instead of Lists). And If so, how would the GetHashCode function look like? I know, its a lot of code to write (boring hash functions), some tips would be sufficient to get me started. Will post tryouts here... And here comes the code so far, the Test obviously fails... public class KeyModifierSet { private readonly List<Key> _keys = new List<Key>(); private readonly List<ModifierKeys> _modifierKeys = new List<ModifierKeys>(); private static readonly Dictionary<KeyModifierSet, Action> _testDict = new Dictionary<KeyModifierSet, Action>(); public static void Test() { _testDict.Add(new KeyModifierSet(Key.A), () => Debug.WriteLine("nothing")); if (!_testDict.ContainsKey(new KeyModifierSet(Key.A))) throw new Exception("Not done yet, help :-)"); } public KeyModifierSet(IEnumerable<Key> keys, IEnumerable<ModifierKeys> modifierKeys) { foreach (var key in keys) _keys.Add(key); foreach (var key in modifierKeys) _modifierKeys.Add(key); } public KeyModifierSet(Key key, ModifierKeys modifierKey) { _keys.Add(key); _modifierKeys.Add(modifierKey); } public KeyModifierSet(Key key) { _keys.Add(key); } }

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  • physics game programming box2d - orientating a turret-like object using torques

    - by egarcia
    This is a problem I hit when trying to implement a game using the LÖVE engine, which covers box2d with Lua scripting. The objective is simple: A turret-like object (seen from the top, on a 2D environment) needs to orientate itself so it points to a target. The turret is on the x,y coordinates, and the target is on tx, ty. We can consider that x,y are fixed, but tx, ty tend to vary from one instant to the other (i.e. they would be the mouse cursor). The turret has a rotor that can apply a rotational force (torque) on any given moment, clockwise or counter-clockwise. The magnitude of that force has an upper limit called maxTorque. The turret also has certain rotational inertia, which acts for angular movement the same way mass acts for linear movement. There's no friction of any kind, so the turret will keep spinning if it has an angular velocity. The turret has a small AI function that re-evaluates its orientation to verify that it points to the right direction, and activates the rotator. This happens every dt (~60 times per second). It looks like this right now: function Turret:update(dt) local x,y = self:getPositon() local tx,ty = self:getTarget() local maxTorque = self:getMaxTorque() -- max force of the turret rotor local inertia = self:getInertia() -- the rotational inertia local w = self:getAngularVelocity() -- current angular velocity of the turret local angle = self:getAngle() -- the angle the turret is facing currently -- the angle of the like that links the turret center with the target local targetAngle = math.atan2(oy-y,ox-x) local differenceAngle = _normalizeAngle(targetAngle - angle) if(differenceAngle <= math.pi) then -- counter-clockwise is the shortest path self:applyTorque(maxTorque) else -- clockwise is the shortest path self:applyTorque(-maxTorque) end end ... it fails. Let me explain with two illustrative situations: The turret "oscillates" around the targetAngle. If the target is "right behind the turret, just a little clock-wise", the turret will start applying clockwise torques, and keep applying them until the instant in which it surpasses the target angle. At that moment it will start applying torques on the opposite direction. But it will have gained a significant angular velocity, so it will keep going clockwise for some time... until the target will be "just behind, but a bit counter-clockwise". And it will start again. So the turret will oscillate or even go in round circles. I think that my turret should start applying torques in the "opposite direction of the shortest path" before it reaches the target angle (like a car braking before stopping). Intuitively, I think the turret should "start applying torques on the opposite direction of the shortest path when it is about half-way to the target objective". My intuition tells me that it has something to do with the angular velocity. And then there's the fact that the target is mobile - I don't know if I should take that into account somehow or just ignore it. How do I calculate when the turret must "start braking"?

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