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  • Fragment not showing up and breaks other buttons on Layout

    - by Devin Crane
    I'm learning how to use Fragments, and trying to add a fragment tag_button.xml at runtime to a FrameLayout tagFragmentContainer deep within another layout, deepLayout.xml. I get no errors, but the fragment doesn't show up. When I make its container visible, I can see a small sliver of layout between the other elements already existing, but then it disappears after onCreateView(), and all the remaining buttons are broken, which is even more confusing to me. tag_button.xml is just a regular layout file with some text and a button. tagFragmentContainer, within a LinearLayout in the middle of a large layout file, deepLayout.xml: <LinearLayout android:id="@+id/tagButtonsLayout" android:layout_marginBottom="10dip" android:visibility="gone" style="@style/Form"> <FrameLayout android:id="@+id/tagFragmentContainer" android:layout_marginBottom="10dip" style="@style/Form"> </FrameLayout> </LinearLayout> In deepLayoutActivity, I make visible tagButtonsLayout and start TagButtonActivity: final LinearLayout anotherlm = (LinearLayout) findViewById(R.id.tagButtonsLayout); anotherlm.setVisibility(View.VISIBLE); Intent i = new Intent (this, TagButtonActivity.class); startActivity(i); TagButtonActivity is as follows: public class TagButtonActivity extends FragmentActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.action_expense); if (savedInstanceState != null) return; TagButtonFragment firstFragment = new TagButtonFragment(); getSupportFragmentManager().beginTransaction().add(R.id.tagFragmentContainer, firstFragment, "tagOne").commit(); } } TagButtonFragment: public class TagButtonFragment extends Fragment { @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // Inflate the layout for this fragment return inflater.inflate(R.layout.tag_button, container, false); } } tag_button.xml: <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" style="@style/Form"> <TextView android:id="@+id/tag_button_header" style="@style/FieldHeader" android:text="example text"/> <RelativeLayout android:id="@+id/tag_button_block" android:layout_width="match_parent" android:layout_marginLeft="2dip" android:layout_marginTop="3dip" android:layout_marginBottom="3dip" android:layout_marginRight="2dip" android:layout_height="43dip" android:clickable="true" android:background="@drawable/row_spinner_selector"> <ImageView android:id="@+id/question_arrow" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="10dip" android:layout_marginRight="10dip" android:layout_alignParentRight="true" android:layout_centerVertical="true" android:src="@drawable/arrow_right"/> <TextView android:id="@+id/tag_question_text" android:layout_toLeftOf="@id/question_arrow" android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_marginLeft="10dip" android:layout_centerVertical="true" android:textColor="@android:color/black" android:singleLine="true" android:ellipsize="end" android:textSize="15sp" android:text="@string/not_selected"/> </RelativeLayout> </LinearLayout> I would certainly appreciate any help in figuring this out from someone who knows fragments better than me! Thanks!

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  • How do I reward my developers for the little things they get right?

    - by Nat
    I am in a tech lead role and my developers get stuff right most of the time. How do I communicate to them thier value to me? (I.e. they have value because I do not have to go through and point out mistakes which means I do not have to watch them like a hawk which frees me to do more useful things). In summary For doing the mundane well on a day to day basis, it is good to recognise the developers effort verbally to them. An honest thankyou that mentions the specific behaviour and its positive repercussions to you personally will be well received, adjust the language to suite each individual. (Note that other developers within earshot may also respond to this by increasing their efforts in this specific activity.) Other things that should be done regularly are: Team drinks In many cultures this is an entirely worthy way of giving the team some time to socialise and relax. Be sure that you do not exclude people who do not drink or are not keen on pub culture. Shared meals are another option. Formal written (email) acknowledgment and praise to senior managers of the teams efforts and successes. (Note that acknowledging individuals alone may damage team spirit) Work the hours you expect your team to do. If they absolutely must work late for a deadline, be there in support Go to bat for the team. Refuse to let them be forced to work long periods of overtime without compensation. Protect them from level politics and stress. Give your team the best equipment you can afford. Good tools show respect and improve productivity. Small or large team rewards where appropriate can consist of many interesting activities/ items. If it allows the team to get together in a fun and even lightly competitive manner it will work (foosball table, go-karting, darts board, video game console etc). Don’t forget to listen to what the team wants, each team will have different ideas. Ensure they are getting a fair deal financially from the company. While different people may have different expectations of their pay, someone being paid unfairly will rot morale for the entire team

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  • Cases of companies taking IP rights of your own personal projects developed outside company time

    - by GSS
    Hi, I have heard of cases where a developer working for a company is also making his own personal projects in his own time, using his own equipment yet the company he works for tries to claim ownership for the project. I really find this annoying, and bang out of order. It should also be illegal. I am in this position (work for a company and working on my own systems - from small class libraries used to practise what I learn in my exam revision to a large commercial-scale system). While I don't know if the company will try to take ownership, all I know is they say they do not want a conflict of interest. Fair enough, my system is developed in my own time using my own equipment. They also say that work time should be for work only, which it is. Funny thing that as work is so boring, easy and slow that I have plenty of free time, which I wish I could spend on something productive - said system. The problem is, my company does not take hiring technical talent seriously. This is my first job, I am a junior coder (but my status/position doesn't really reflect what I can do), but I am the only developer. Likewise with the guy who controls Windows Server. As the contract does not say anything about taking ownership, I would assume they would. They would try to milk my success (I've made a good impression so I am sure they would). How can this be allowed? Are there any examples of this happening to any fellow Stacker here? It really makes my blood boil. What I find funny is that my company hardly has the expertise and resources to even be able to successfully run a project of my size. What I do at work is an ASP.NET application consisting of five pages, and even then there are flaws in the project. If I told them that they would also have to take responsibility for flaws in the project, then they would think twice! It's exactly because of this I save the best code for myself and at work I write rubbish code full of code smells. The company don't really care about error handling, as long as the business functionality works (ie a scheduled email sends, but there is no error handling). They'd think twice when they see the embarassment and business cost of a YSOD...

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  • General Questions on setting up Subversion (w/Netbeans) and web development workflow.

    - by Roeland
    Hey guys, I am web developer who currently works mostly on his own but, some projects require outside coding help (my brother.) Anyway, after running in to the problem of "working on the same files" and "saving over each others edits" I decided to research ways to avoid this. Through the help of stackoverflow I decided on subversion. My setup is the following: A windows 2008 server with a clean install. My desktop which is on the local network of the server. Then my brothers desktop which is at his house, not on lan. We both prefer to use netbeans for development. My Questions: How do we set this thing up correctly and most optimally. Here is my current setup and work flow. dev site: in the past I just created sub domains with my web host for test sites (company1.bythepixel.com, company2.bythepixel.com), and editted those sites with netbeans set up having remote sources (ftp). how do i set up my netbeans now? should I set it up with remote sources? I guess I may need to set up a web server on my local server. I'm just not sure of the work flow. When i hit save in netbeans.. will it update the repository.. then do i need to update the site from the repository somehow? live site: when going live, i would just copy all the files from the dev site into the live site. from what i gather i should be able to update the site from the dev repository? Currently I am toying with virtualsvn server (http://www.visualsvn.com/server/) on my local server. It looks like it is set up to use the http protocol. Is there advantages to this or should I consider something that does the file//. Do you recommend any other subversion software that would run on my 2008 box? how will my brother connect? should i set up a permanent vpn from his house to mine? suggestions? (not that important) how do I deal with databases, there anyway to do subversion on database? I know I have a lot of questions and I am trying to read / make sense of the free online subversion book, but its all so overwhelming! Wish there was a small subversion for dummies guide :)

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  • CSS selectors : should I make my CSS easier to read or optimise the speed

    - by Laurent Bourgault-Roy
    As I was working on a small website, I decided to use the PageSpeed extension to check if their was some improvement I could do to make the site load faster. However I was quite surprise when it told me that my use of CSS selector was "inefficient". I was always told that you should keep the usage of the class attribute in the HTML to a minimum, but if I understand correctly what PageSpeed tell me, it's much more efficient for the browser to match directly against a class name. It make sense to me, but it also mean that I need to put more CSS classes in my HTML. It make my .css file harder to read. I usually tend to mark my CSS like this : #mainContent p.productDescription em.priceTag { ... } Which make it easy to read : I know this will affect the main content and that it affect something in a paragraph tag (so I wont start to put all sort of layout code in it) that describe a product and its something that need emphasis. However it seem I should rewrite it as .priceTag { ... } Which remove all context information about the style. And if I want to use differently formatted price tag (for example, one in a list on the sidebar and one in a paragraph), I need to use something like that .paragraphPriceTag { ... } .listPriceTag { ... } Which really annoy me since I seem to duplicate the semantic of the HTML in my classes. And that mean I can't put common style in an unqualified .priceTag { ... } and thus I need to replicate the style in both CSS rule, making it harder to make change. (Altough for that I could use multiple class selector, but IE6 dont support them) I believe making code harder to read for the sake of speed has never been really considered a very good practice . Except where it is critical, of course. This is why people use PHP/Ruby/C# etc. instead of C/assembly to code their site. It's easier to write and debug. So I was wondering if I should stick with few CSS classes and complex selector or if I should go the optimisation route and remove my fancy CSS selectors for the sake of speed? Does PageSpeed make over the top recommandation? On most modern computer, will it even make a difference?

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  • Suggestions for designing large-scale Java webapp from the group up

    - by Chris Thompson
    Hi all, I'm about to start developing a large-scale system and I'm struggling with which direction to proceed. I've done plenty of Java web apps before and I have plenty of experience with servlet containers and GWT and some experience with Spring. The problem is most of my webapps have been thrown together just to be a proof of concept and what I'm struggling with is what set of frameworks to use. I need to have both a browser based application as well as a web service designed to support access from mobile devices (Android and iPhone for now). Ideally, I'd like to design this system in such a way that I don't end up rewriting all of my servlets for each client (browser and phone) although I don't mind having some small checks in there to properly format the data. In addition, although I'm the only developer now, that won't necessarily be the case down the road and I'd like to design something that scales well both with regards to traffic and number of developers (isn't just a nightmare to maintain). So where I am now is planning on using GWT to design the browser-based interface but I'm struggling with how to reuse that code with to present the interface (most likely xml) for the mobile devices. Using GWT RPC would, I think, make it relatively easy to do all of the AJAX in the browser, but might make generating xml for the mobile phones difficult. In addition, I like the idea of using something like Hibernate for persistence and Spring Security to secure the whole thing. Again, I'm not sure how well those will cooperate with GWT (I think Hibernate should be fine...) There's obviously a lot more to this than I've presented here, but I've tried to give you the 5-minute overview. I'm a bit stumped and was wondering if anybody in the community had any experience starting from this place. Does what I'm trying to do make sense? Is it realistic? I have no doubt I can make all of these frameworks speak the same language, I'm just wondering if it's worth my time to fight with them. Also, am I missing a framework that would be really beneficial? Thanks in advance and sorry for the relatively broad question... Chris

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  • Most efficient method to query a Young Tableau

    - by Matthieu M.
    A Young Tableau is a 2D matrix A of dimensions M*N such that: i,j in [0,M)x[0,N): for each p in (i,M), A[i,j] <= A[p,j] for each q in (j,N), A[i,j] <= A[i,q] That is, it's sorted row-wise and column-wise. Since it may contain less than M*N numbers, the bottom-right values might be represented either as missing or using (in algorithm theory) infinity to denote their absence. Now the (elementary) question: how to check if a given number is contained in the Young Tableau ? Well, it's trivial to produce an algorithm in O(M*N) time of course, but what's interesting is that it is very easy to provide an algorithm in O(M+N) time: Bottom-Left search: Let x be the number we look for, initialize i,j as M-1, 0 (bottom left corner) If x == A[i,j], return true If x < A[i,j], then if i is 0, return false else decrement i and go to 2. Else, if j is N-1, return false else increment j This algorithm does not make more than M+N moves. The correctness is left as an exercise. It is possible though to obtain a better asymptotic runtime. Pivot Search: Let x be the number we look for, initialize i,j as floor(M/2), floor(N/2) If x == A[i,j], return true If x < A[i,j], search (recursively) in A[0:i-1, 0:j-1], A[i:M-1, 0:j-1] and A[0:i-1, j:N-1] Else search (recursively) in A[i+1:M-1, 0:j], A[i+1:M-1, j+1:N-1] and A[0:i, j+1:N-1] This algorithm proceed by discarding one of the 4 quadrants at each iteration and running recursively on the 3 left (divide and conquer), the master theorem yields a complexity of O((N+M)**(log 3 / log 4)) which is better asymptotically. However, this is only a big-O estimation... So, here are the questions: Do you know (or can think of) an algorithm with a better asymptotical runtime ? Like introsort prove, sometimes it's worth switching algorithms depending on the input size or input topology... do you think it would be possible here ? For 2., I am notably thinking that for small size inputs, the bottom-left search should be faster because of its O(1) space requirement / lower constant term.

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  • Getting TypeError: Error #1009: Cannot access a property or method of a null object reference.

    - by nemade-vipin
    hello friends, I have created small application for login in flex desktop application. In which I am refering webservice method for login for this have created the Authentication class. Now I want to refer different Textinput value for mobile no and Textinput value for password. In my Authentication class. for this I have created the object of mxml class.And using this I am getting the mobile no value and password value in My Action script class. This my code :- SBTS.mxml file xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" public function login():void { var User:Authentication; User = new Authentication(); User.authentication(); } ]] text=" Select Child."/ Action script class :- package src { import adobe.utils.XMLUI; import generated.webservices.*; import mx.collections.ArrayCollection; import mx.controls.Alert; import mx.rpc.events.FaultEvent; public class Authentication { [ Bindable] private var childName:ArrayCollection; [ Bindable] private var childId:ArrayCollection; private var photoFeed:ArrayCollection; private var arrayOfchild:Array; private var newEntry:GetSBTSMobileAuthentication; public var user:SBTSWebService; public var mxmlobj:SBTS; public function authentication():void { user = new SBTSWebService(); if(user!=null) { user.addSBTSWebServiceFaultEventListener(handleFaults); user.addgetSBTSMobileAuthenticationEventListener(authenticationResult); newEntry = new GetSBTSMobileAuthentication(); if(newEntry!=null) { mxmlobj = new SBTS(); if(mxmlobj != null) { newEntry.mobile = mxmlobj.mobileno.text; // Getting error here error mention below newEntry.password= mxmlobj.password.text; } user.getSBTSMobileAuthentication(newEntry); } } } public function handleFaults(event:FaultEvent):void { Alert.show( "A fault occured contacting the server. Fault message is: " + event.fault.faultString); } public function authenticationResult(event:GetSBTSMobileAuthenticationResultEvent):void { if(event.result != null && event.result._return0) { if(event.result._return 0) { var UserId:int = event.result._return; if(mxmlobj != null) { mxmlobj.loginform.enabled = false; mxmlobj.viewstack2.selectedIndex=1; } } else { Alert.show( "Authentication fail"); } } } } } I am getting this error :- TypeError: Error #1009: Cannot access a property or method of a null object reference. at SBTSBusineesObject::Authentication/authentication()[E:\Users\User1\Documents\Fl ex Builder 3\SBTS\src\SBTSBusineesObject\Authentication.as:35] at SBTS/login()[E:\Users\User1\Documents\Flex Builder 3\SBTS\src\SBTS.mxml:12] at SBTS/___SBTS_Button1_click()[E:\Users\User1\Documents\Flex Builder 3\SBTS\src\SBTS.mxml:27] please help me to remove this error.

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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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  • Eclipselink read complex oject model in an ordered way

    - by Raven
    Hi, I need to read a complex model in an ordered way with eclipselink. The order is mandantory because it is a huge database and I want to have an output of a small portion of the database in a jface tableview. Trying to reorder it in the loading/quering thread takes too long and ordering it in the LabelProvider blocks the UI thread too much time, so I thought if Eclipselink could be used that way, that the database will order it, it might give me the performance I need. Unfortunately the object model can not be changed :-( The model is something like: @SuppressWarnings("serial") @Entity public class Thing implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; private String name; @OneToMany(cascade=CascadeType.ALL) @PrivateOwned private List<Property> properties = new ArrayList<Property>(); ... // getter and setter following here } public class Property implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; @OneToOne private Item item; private String value; ... // getter and setter following here } public class Item implements Serializable { @Id @GeneratedValue(strategy = GenerationType.TABLE) private int id; private String name; .... // getter and setter following here } // Code end In the table view the y-axis is more or less created with the query Query q = em.createQuery("SELECT m FROM Thing m ORDER BY m.name ASC"); using the "name" attribute from the Thing objects as label. In the table view the x-axis is more or less created with the query Query q = em.createQuery("SELECT m FROM Item m ORDER BY m.name ASC"); using the "name" attribute from the Item objects as label. Each cell has the value Things.getProperties().get[x].getValue() Unfortunately the list "properties" is not ordered, so the combination of cell value and x-axis column number (x) is not necessarily correct. Therefore I need to order the list "properties" in the same way as I ordered the labeling of the x-axis. And exactly this is the thing I dont know how it is done. So querying for the Thing objects should return the list "properties" "ORDER BY name ASC" but of the "Item"s objects. My ideas are something like having a query with two JOINs. Joing Things with Property and with Item but somehow I was unable to get it to work yet. Thank you for your help and your ideas to solve this riddle.

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  • pager problem with drupal and taxonomy

    - by andersandersson666
    Ok, so this is probably a silly question, but i thought i'd put it out there anyway: I know it's a strange solution to a simple problem, but i needed to control the listing of the nodes in the taxonomy pages, which i didn't feel i got the traditional way. So i went ahead and created a module that fetches the nodes based on taxonomy (taxonomy_select_nodes()), and i wanted a pager to go along with that. Here's the code: function theModule_recipeList(){ $path = drupal_get_path_alias($_GET['q']); $args = explode("/",$path); $themePath = drupal_get_path("theme", "theTheme"); $term = taxonomy_get_term_by_name($args[1]); $tid = $term[0]->tid; $nodes = taxonomy_select_nodes(array($tid)); $output = "<div id='recipeListWrapper'>"; while($row = db_fetch_object($nodes)){ $node = node_load($row->nid); if($node->uid != 1){ $userClass="user"; } else{ $userClass="admin"; } $output .= " <div class='receptThumbnailWrapper'> <div class='wrapper'> <img src='".base_path().$themePath."/graphics/recept-default-small.png' /> <h3><a href='".base_path() . $node->path."'>".$node->title."</a></h3> <div class='recipeType $userClass'></div> </div> </div> "; } $output .= "</div>"; return $output; } Now, the module works as i planned and all (even though it is a duct tape sort of solution, i know), and the pager prints and works. The problem is that the pager prints before anything else. I suspect that it is because i call taxonomy_select_nodes before $output is returned, but i need it to get the nodes i want. Please, any suggestions is greatly appreciated. /Anders

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  • TFS CM resource recommendations / some questions

    - by John
    I am working with a small development shop that consists of a group of 5 developers and 1 QA person. We are using TFS and need to get more sophisticated on how we use this tool. Currently the development team checks in their code each evening. A nightly build runs and pushes the output out on a network share. Our QA person uses this build for testing the next day. Sometimes the build off the trunk codebase has issues/bugs that hinder the QA process, and it hasn’t been a giant issue in the past, but we now want to get to a state where we have our QA person testing on a stable QA build. So I believe we need to create a branch (call it QA), and the developers will continue to develop off the trunk, but the QA person will use builds created from code in the QA branch. Seems simple enough, but we have started doing code reviews as well. So we have another desire in that only code that has been code reviewed can be promoted to the QA branch. Each developer works off a TFS item, and when they check in a changeset, they do it against a TFS item which creates a link between a checked in code file and a TFS item. Eventually the TFS item becomes complete and ready for code review. All code attached to the TFS item is reviewed. How can the versions of these files get promoted to the QA branch? In the QA branch, if a bug is found, we want to fix it in the QA branch and have the changes migrated back to the trunk. I believe TFS has a way to automatically do this doesn’t it? Long story short, we want to get to a build and CM environment that I believe is pretty standard, but we are unaware of how to make this happen with TFS. Given our situation above, can someone point out a book or website(s) that would address our specific needs? We would like to make this happen without having to get too deep in CM theory or TFS. I very much appreciate any and all suggestions! Thanks, John

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  • XML Parsing Error - C#

    - by Indebi
    My code is having an XML parsing error at line 7 position 32 and I'm not really sure why Exact Error Dump 5/1/2010 10:21:42 AM System.Xml.XmlException: An error occurred while parsing EntityName. Line 7, position 32. at System.Xml.XmlTextReaderImpl.Throw(Exception e) at System.Xml.XmlTextReaderImpl.Throw(String res, Int32 lineNo, Int32 linePos) at System.Xml.XmlTextReaderImpl.HandleEntityReference(Boolean isInAttributeValue, EntityExpandType expandType, Int32& charRefEndPos) at System.Xml.XmlTextReaderImpl.ParseAttributeValueSlow(Int32 curPos, Char quoteChar, NodeData attr) at System.Xml.XmlTextReaderImpl.ParseAttributes() at System.Xml.XmlTextReaderImpl.ParseElement() at System.Xml.XmlTextReaderImpl.ParseElementContent() at System.Xml.XmlTextReaderImpl.Read() at System.Xml.XmlLoader.LoadNode(Boolean skipOverWhitespace) at System.Xml.XmlLoader.LoadDocSequence(XmlDocument parentDoc) at System.Xml.XmlLoader.Load(XmlDocument doc, XmlReader reader, Boolean preserveWhitespace) at System.Xml.XmlDocument.Load(XmlReader reader) at System.Xml.XmlDocument.Load(String filename) at Lookoa.LoadingPackages.LoadingPackages_Load(Object sender, EventArgs e) in C:\Users\Administrator\Documents\Visual Studio 2010\Projects\Lookoa\Lookoa\LoadingPackages.cs:line 30 Xml File, please note this is just a sample because I want the program to work before I begin to fill this repository <repo> <Packages> <TheFirstPackage id="00001" longname="Mozilla Firefox" appver="3.6.3" pkgver="0.01" description="Mozilla Firefox is a free and open source web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. A Net Applications statistic put Firefox at 24.52% of the recorded usage share of web browsers as of March 2010[update], making it the second most popular browser in terms of current use worldwide after Microsoft's Internet Explorer." cat="WWW" rlsdate="4/8/10" pkgloc="http://google.com"/> </Packages> <categories> <WWW longname="World Wide Web" description="Software that's focus is communication or primarily uses the web for any particular reason."> </WWW> <Fun longname="Entertainment & Other" description="Music Players, Video Players, Games, or anything that doesn't fit in any of the other categories."> </Fun> <Work longname="Productivity" description="Application's commonly used for occupational needs or, stuff you work on"> </Work> <Advanced longname="System & Security" description="Applications that protect the computer from malware, clean the computer, and other utilities."> </Advanced> </categories> </repo> Small part of C# Code //Loading the Package and Category lists //The info from them is gonna populate the listboxes for Category and Packages Repository.Load("repo.info"); XmlNodeList Categories = Repository.GetElementsByTagName("categories"); foreach (XmlNode Category in Categories) { CategoryNumber++; CategoryNames[CategoryNumber] = Category.Name; MessageBox.Show(CategoryNames[CategoryNumber]); } The Messagebox.Show() is just to make sure it's getting the correct results

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  • In GWT I'd like to load the main page on www.domain.com and a dynamic page on www.domain.com/xyz - I

    - by Mike Brecht
    Hi, I have a question for which I'm sure there must a simple solution. I'm writing a small GWT application where I want to achieve this: www.domain.com : should serve the welcome page www.domain.com/xyz : should serve page xyz, where xyz is just a key for an item in a database. If there is an item associated with key xyz, I'll load that and show a page, otherwise I'll show a 404 error page. I was trying to modify the web.xml file accordingly but I just couldn't make it work. I could make it work with an url-pattern if the key in question is after another /, for example: www.domain.com/search/xyz. However, I'd like to have the key xyz directly following the root / (http://www.domain.com/xyz). Something like <servlet-mapping> <servlet-name>main</servlet-name> <url-pattern>/</url-pattern> </servlet-mapping> doesn't seem to work as I don't know how to address the main page index.html (as it's not an actual servlet) which will then load my main GWT module. I could make it work with a bad work around (see below): Redirecting a 404 exception to index.html and then doing the look up in the main entry point, but I'm sure that's not the best practice, also for SEO purposes. Can anyone give me a hint on how to configure the web.xml with GWT for my purpose? Thanks a lot. Mike Work-around via 404: Web.xml: <web-app> <error-page> <exception-type>404</exception-type> <location>/index.html</location> </error-page> <welcome-file-list> <welcome-file>index.html</welcome-file> </welcome-file-list> </web-app> index.html -- Main Entry point -- onModuleLoad(): String path = Window.Location.getPath(); if (path == null || path.length() == 0 || path.equalsIgnoreCase("/") || path.equalsIgnoreCase("/index.html")) { ... // load main page } else { lookup(path.substring(1)); // that's key xyz

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  • Network communication for a turn based board game

    - by randooom
    Hi all, my first question here, so please don't be to harsh if something went wrong :) I'm currently a CS student (from Germany, if this info is of any use ;) ) and we got a, free selectable, programming assignment, which we have to write in a C++/CLI Windows Forms Application. My team, two others and me, decided to go for a network-compatible port of the board game Risk. We divided the work in 3 Parts, namely UI, game logic and network. Now we're on the part where we have to get everything working together and the big question mark is, how to get the clients synchronized with each other? Our approach so far is, that each client has all information necessary to calculate and/or execute all possible actions. Actually the clients have all information available at all, aside from the game-initializing phase (add players, select map, etc.), which needs one "super-client" with some extra stuff to control things. This is the standard scenario of our approach: player performs action, the action is valid and got executed on the players client action is sent over the network action is executed on the other clients The design (i.e. no or code so far) we came up with so far, is something like the following pseudo sequence diagram. Gui, Controller and Network implement all possible actions (i.e. all actions which change data) as methods from an interface. So each part can implement the method in a way to get their job done. Example with Action(): On the player side's Client: Player-->Gui.Action() Gui-->Controller.Action() Controller-->Logic.Action (Logic.Action() == NoError)? Controller-->Network.Action() Network-->Parser.ParseAction() Network.Send(msg) On all other clients: Network.Recv(msg) Network-->Parser.Deparse(msg) Parser-->Logic.Action() Logic-->Gui.Action() The questions: Is this a viable approach to our task? Any better/easier way to this? Recommendations, critique? Our knowledge (so you can better target your answer): We are on the beginner side, in regards to programming on a somewhat larger projects with a small team. All of us have some general programming experience and basic understanding of the .Net Libraries and Windows Forms. If you need any further information, please feel free to ask.

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  • when I click submit it should change the text and update the row something is wrong there

    - by Yousef Altaf
    good morning programers, I have this small code which content a news control panel and I made a submit button there to active or inactive the news row so if I click on this button it should change if it's active it will be inactive it worked but there's something wrong there when I click on item one it updates the last on the table not the first on as it should do. here is the code that I use <?php $getNewsData="select * from news"; $QgetNewsData=$db->query($getNewsData)or die($db->error); $count=mysqli_num_rows($QgetNewsData); while($newsRow = mysqli_fetch_array($QgetNewsData)) { $getActivityStatus=$newsRow['news_activity']; switch($getActivityStatus){ case 1: echo"<input style='color:red; font-weight:bold; background:none; border:0;' name='inactive' type='submit' value='?????' /><input name='inActive' type='hidden' value='".$newsRow['news_id']."'/>"; break; case 0: echo"<input style='color:green; font-weight:bold; background:none; border:0;' name='active' type='submit' value='?????' /><input name='Active' type='hidden' value='".$newsRow['news_id']."'/>"; break;} } if(isset($_POST['inactive'])){ $inActive=$_POST['inActive']; echo $inActive; $updateStatus="UPDATE news SET news_activity=0 WHERE news_id='".$inActive."' "; $QupdateStatus=$db->query($updateStatus)or die($db->error); if($QupdateStatus){ } } if(isset($_POST['active'])){ $Active=$_POST['Active']; echo $Active; $updateStatus="UPDATE news SET news_activity=1 WHERE news_id='".$Active."' "; $QupdateStatus=$db->query($updateStatus)or die($db->error); if($QupdateStatus){ header("Location:CpanelHome.php?id=7"); } } ?> please any idea to solve this problem. Thanks, regards

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  • Is this way of storing typed objects in memory good?

    - by Pindatjuh
    This is an "is this okay, or can it be done better" question. Topic: Storing typed objects in memory. Background information: I'm building a compiler for the x86-32 platform for my language. My goal includes typed objects. Idea: Every primitive is a semi-class (it can be used as if it was a normal class, but it's stored more compact). Every class is represented by primitives and some meta-data (containing class-properties, inheritance stuff, etc.). The meta-data is complex: it doesn't use fields but instead context-switches. For primitives, the meta-data is very small, compared to a "real" class, which is alot bigger. This enables another idea that "primitives are objects", in my language, which I found nessecairy. Example: If I have an array of 32 booleans, then the pure content of this array is exactly 4 byte (32 bits of booleans). The meta-data will contain flags that the type is an array of booleans, which contains 32 entries. The meta-data is very compacted, on bit-level: using a sort of "packing" mechanism, which is read by a FSM at runtime, when doing inspection of the type (like when passing the object to methods for checking, etc.) For instance (read from left to right, top to bottom, remember vertical possition when going to the right, and check nearest column header for meaning of switch): Primitive? Array? Type-Meta 1 Byte? || Size (1 byte) 1 1 [...] 1 [...] done 0 2 Bytes? || Size (2 bytes) 1 [...] done || Size (4 bytes) 0 [...] done Integer? 1 Byte? 2 Bytes? 0 1 0 1 done 1 done 0 done Boolean? Byte? 0 1 0 done 1 done More-Primitives 0 .... Class-Stuff (Huge) 0 ... (After reaching done the data is inserted. || = byte alignement. [...] is variable sized. ... is not described here, for simplicity. And let's call them cost-based-data-structures.) For an array of 32 booleans containing all true values, the memory for this type would be (read top-down): 1 Primitive 1 Array 1 ArrayType: Primitive 0 Not-Array 0 Not-Integer 1 Boolean 0 Not-Byte (thus bit) 1 Integer Size: 1 Byte 00100000 Array size 11111111 11111111 11111111 11111111 Data Thus, 8 bytes represent 32 booleans in an array: 11100101 00100000 11111111 11111111 11111111 11111111 Is this okay, or can it be done better?

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  • Experienced developer trying to get outsourcing contract with current client.

    - by Mike
    I work for a major bank as a contract software developer. I've been there a few months, and without exception this place has the worst software practices I've ever seen. The software my team makes has no formal testing, terrible code (not reusable, hard to read, etc), minimal documentation, no defined development process and an absolutely sickening amount of waste due to bureaucratic overhead. Part of my contract is to maintain a group of thousands of very poorly written batch jobs. When one of the jobs fails (read: crashes), it's a developers job to look at the source, figure out what's wrong, fix it, and check it in. There is no quality assurance process or auditing of the results whatsoever. Once the developer says "it works" a manager signs off and it goes into production. What's disturbing is that these jobs essentially grab market data and put it into a third-party risk management system, which provides the bank with critical intelligence. I've discovered the disturbing truth that this has been happening since the 90s and nobody really has evidence the system is getting the correct data! Without going into details, an issue arose on Friday that was so horrible I actually stormed out of the place. I was ready to quit, but I decided to just get out to calm my nerves and possibly go back Monday. I've been reflecting today on how to handle this. I have realized that, in probably less than 6 months, I could (with 2 other developers) remake a large component of this system. The new system would provide them with, as primary benefits, a maintainable codebase less prone to error and a solid QA framework. To do it properly I would have to be outside the bank, the internal bureaucracy is just too much. And moreover, I think a bank is fundamentally not a place that can make good software. This is my plan. Write a report explaining in depth all the problems with their current system Explain why their software practices fail and generate a tremendous amount of error and waste. Use this as the basis for claiming the project must be developed externally. Write a high level development plan, including what resources I will require Hand 1,2,3 to my manager, hopefully he passes it up the chain. Worst case he fires me, but this isn't so bad. Convinced Executive decides to award my company a contract for the new system I have 8 years experience as a software contractor and have delivered my share of successful software products, but all working in-house for small/medium sized companies. When I read this over, I think I have a dynamite plan. But since this is the first time doing something this bold so I have my doubts. My question is, is this a good idea? If you think not, please spare no detail.

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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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  • Going from a math career to a cs career: how to do it?

    - by Joseph
    Hey, I'm looking for some advice on how to successfully make the transition from mathematics to CS. My academic background is in mathematics (BS and MSc), and I've taken loads of math courses as well. You name it, and I took it: Measure Theory, Algebra, PDES, Manifolds, Complex Analysis, etc. I progressed quite far along this track, and at one point, I thought I would be a professional mathematician...But around the time I was finishing my MSc, I really got sick of it. Studying very abstract mathematics was fun, but it really lost it's appeal to me. Outside of a couple hundred people, I'm not sure if anybody would understand my research. I did not want to be 60 years old and say that my only contribution to the world consisted of published papers. Anyways, I've been an off and on hobbyist programmer since 2002. I've programmed in C and Java (just small projects), and I really started to be drawn to the area as time passed. There's a real appeal to CS work because, well, it actually means something to other people out there! I enjoy all parts of it: designing webpages (a real artistic appeal). On the other end, I do enjoy toying with compilers and more nitty-gritty stuff as well. Suffice to say, I have broad interests out there. Anyways, I know it's a bit late, but I was wondering if there were other folks out there who made the change, and if so, how I could do so. I know I have some fairly big gaps to fill in terms of data structures, lack of internship experience, etc. But I really would like to make this work. So my question is simply: How can I make the switch from math to CS? To pay the bills, I'll be doing financial analysis for a company, but I'd like to eventually transition into a developer type position. I've been reading "Algorithm Design" by Tardos and doing all the problems. It's not hard to make progress since the problems are far more concrete than the stuff I've been doing the past six years. I feel I can make fairly rapid progress in picking up all the materials from data structures, etc. but none of it can substitute the past several years I've lost. Anyways, I'm eager to learn but would love some advice/concrete direction. Thanks, Joseph

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  • How can a test script inform R CMD check that it should emit a custom message?

    - by mariotomo
    I'm writing a R package (delftfews) here at office. we are using svUnit for unit testing. our process for describing new functionality: we define new unit tests, initially marked as DEACTIVATED; one block of tests at a time we activate them and implement the function described by the tests. almost all the time we have a small amount of DEACTIVATED tests, relative to functions that might be dropped or will be implemented. my problem/question is: can I alter the doSvUnit.R so that R CMD check pkg emits a NOTE (i.e. a custom message "NOTE" instead of "OK") in case there are DEACTIVATED tests? as of now, we see only that the active tests don't give error: . . * checking for unstated dependencies in tests ... OK * checking tests ... Running ‘doSvUnit.R’ OK * checking PDF version of manual ... OK which is all right if all tests succeed, but less all right if there are skipped tests and definitely wrong if there are failing tests. In this case, I'd actually like to see a NOTE or a WARNING like the following: . . * checking for unstated dependencies in tests ... OK * checking tests ... Running ‘doSvUnit.R’ NOTE 6 test(s) were skipped. WARNING 1 test(s) are failing. * checking PDF version of manual ... OK As of now, we have to open the doSvUnit.Rout to check the real test results. I contacted two of the maintainers at r-forge and CRAN and they pointed me to the sources of R, in particular the testing.R script. if I understand it correctly, to answer this question we need patching the tools package: scripts in the tests directory are called using a system call, output (stdout and stderr) go to one single file, there are two possible outcomes: ok or not ok, so I opened a change request on R, proposing something like bit-coding the return status, bit-0 for ERROR (as it is now), bit-1 for WARNING, bit-2 for NOTE. with my modification, it would be easy producing this output: . . * checking for unstated dependencies in tests ... OK * checking tests ... Running ‘doSvUnit.R’ NOTE - please check doSvUnit.Rout. WARNING - please check doSvUnit.Rout. * checking PDF version of manual ... OK Brian Ripley replied "There are however several packages with properly written unit tests that do signal as required. Please do take this discussion elsewhere: R-bugs is not the place to ask questions." and closed the change request. anybody has hints?

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  • How to use CFNetwork to get byte array from sockets?

    - by Vic
    Hi, I'm working in a project for the iPad, it is a small program and I need it to communicate with another software that runs on windows and act like a server; so the application that I'm creating for the iPad will be the client. I'm using CFNetwork to do sockets communication, this is the way I'm establishing the connection: char ip[] = "192.168.0.244"; NSString *ipAddress = [[NSString alloc] initWithCString:ip]; /* Build our socket context; this ties an instance of self to the socket */ CFSocketContext CTX = { 0, self, NULL, NULL, NULL }; /* Create the server socket as a TCP IPv4 socket and set a callback */ /* for calls to the socket's lower-level connect() function */ TCPClient = CFSocketCreate(NULL, PF_INET, SOCK_STREAM, IPPROTO_TCP, kCFSocketDataCallBack, (CFSocketCallBack)ConnectCallBack, &CTX); if (TCPClient == NULL) return; /* Set the port and address we want to listen on */ struct sockaddr_in addr; memset(&addr, 0, sizeof(addr)); addr.sin_len = sizeof(addr); addr.sin_family = AF_INET; addr.sin_port = htons(PORT); addr.sin_addr.s_addr = inet_addr([ipAddress UTF8String]); CFDataRef connectAddr = CFDataCreate(NULL, (unsigned char *)&addr, sizeof(addr)); CFSocketConnectToAddress(TCPClient, connectAddr, -1); CFRunLoopSourceRef sourceRef = CFSocketCreateRunLoopSource(kCFAllocatorDefault, TCPClient, 0); CFRunLoopAddSource(CFRunLoopGetCurrent(), sourceRef, kCFRunLoopCommonModes); CFRelease(sourceRef); CFRunLoopRun(); And this is the way I sent the data, which basically is a byte array /* The native socket, used for various operations */ // TCPClient is a CFSocketRef member variable CFSocketNativeHandle sock = CFSocketGetNative(TCPClient); Byte byteData[3]; byteData[0] = 0; byteData[1] = 4; byteData[2] = 0; send(sock, byteData, strlen(byteData)+1, 0); Finally, as you may have noticed, when I create the server socket, I registered a callback for the kCFSocketDataCallBack type, this is the code. void ConnectCallBack(CFSocketRef socket, CFSocketCallBackType type, CFDataRef address, const void *data, void *info) { // SocketsViewController is the class that contains all the methods SocketsViewController *obj = (SocketsViewController*)info; UInt8 *unsignedData = (UInt8 *) CFDataGetBytePtr(data); char *value = (char*)unsignedData; NSString *text = [[NSString alloc]initWithCString:value length:strlen(value)]; [obj writeToTextView:text]; [text release]; } Actually, this callback is being invoked in my code, the problem is that I don't know how can I get the data that the windows client sent me, I'm expecting to receive an array of bytes, but I don't know how can I get those bytes from the data param. If anyone can help me to find a way to do this, or maybe me point me to another way to get the data from the server in my client application I would really appreciate it. Thanks.

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  • Why is numpy's einsum faster than numpy's built in functions?

    - by Ophion
    Lets start with three arrays of dtype=np.double. Timings are performed on a intel CPU using numpy 1.7.1 compiled with icc and linked to intel's mkl. A AMD cpu with numpy 1.6.1 compiled with gcc without mkl was also used to verify the timings. Please note the timings scale nearly linearly with system size and are not due to the small overhead incurred in the numpy functions if statements these difference will show up in microseconds not milliseconds: arr_1D=np.arange(500,dtype=np.double) large_arr_1D=np.arange(100000,dtype=np.double) arr_2D=np.arange(500**2,dtype=np.double).reshape(500,500) arr_3D=np.arange(500**3,dtype=np.double).reshape(500,500,500) First lets look at the np.sum function: np.all(np.sum(arr_3D)==np.einsum('ijk->',arr_3D)) True %timeit np.sum(arr_3D) 10 loops, best of 3: 142 ms per loop %timeit np.einsum('ijk->', arr_3D) 10 loops, best of 3: 70.2 ms per loop Powers: np.allclose(arr_3D*arr_3D*arr_3D,np.einsum('ijk,ijk,ijk->ijk',arr_3D,arr_3D,arr_3D)) True %timeit arr_3D*arr_3D*arr_3D 1 loops, best of 3: 1.32 s per loop %timeit np.einsum('ijk,ijk,ijk->ijk', arr_3D, arr_3D, arr_3D) 1 loops, best of 3: 694 ms per loop Outer product: np.all(np.outer(arr_1D,arr_1D)==np.einsum('i,k->ik',arr_1D,arr_1D)) True %timeit np.outer(arr_1D, arr_1D) 1000 loops, best of 3: 411 us per loop %timeit np.einsum('i,k->ik', arr_1D, arr_1D) 1000 loops, best of 3: 245 us per loop All of the above are twice as fast with np.einsum. These should be apples to apples comparisons as everything is specifically of dtype=np.double. I would expect the speed up in an operation like this: np.allclose(np.sum(arr_2D*arr_3D),np.einsum('ij,oij->',arr_2D,arr_3D)) True %timeit np.sum(arr_2D*arr_3D) 1 loops, best of 3: 813 ms per loop %timeit np.einsum('ij,oij->', arr_2D, arr_3D) 10 loops, best of 3: 85.1 ms per loop Einsum seems to be at least twice as fast for np.inner, np.outer, np.kron, and np.sum regardless of axes selection. The primary exception being np.dot as it calls DGEMM from a BLAS library. So why is np.einsum faster that other numpy functions that are equivalent? The DGEMM case for completeness: np.allclose(np.dot(arr_2D,arr_2D),np.einsum('ij,jk',arr_2D,arr_2D)) True %timeit np.einsum('ij,jk',arr_2D,arr_2D) 10 loops, best of 3: 56.1 ms per loop %timeit np.dot(arr_2D,arr_2D) 100 loops, best of 3: 5.17 ms per loop The leading theory is from @sebergs comment that np.einsum can make use of SSE2, but numpy's ufuncs will not until numpy 1.8 (see the change log). I believe this is the correct answer, but have not been able to confirm it. Some limited proof can be found by changing the dtype of input array and observing speed difference and the fact that not everyone observes the same trends in timings.

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  • mysql index optimization for a table with multiple indexes that index some of the same columns

    - by Sean
    I have a table that stores some basic data about visitor sessions on third party web sites. This is its structure: id, site_id, unixtime, unixtime_last, ip_address, uid There are four indexes: id, site_id/unixtime, site_id/ip_address, and site_id/uid There are many different types of ways that we query this table, and all of them are specific to the site_id. The index with unixtime is used to display the list of visitors for a given date or time range. The other two are used to find all visits from an IP address or a "uid" (a unique cookie value created for each visitor), as well as determining if this is a new visitor or a returning visitor. Obviously storing site_id inside 3 indexes is inefficient for both write speed and storage, but I see no way around it, since I need to be able to quickly query this data for a given specific site_id. Any ideas on making this more efficient? I don't really understand B-trees besides some very basic stuff, but it's more efficient to have the left-most column of an index be the one with the least variance - correct? Because I considered having the site_id being the second column of the index for both ip_address and uid but I think that would make the index less efficient since the IP and UID are going to vary more than the site ID will, because we only have about 8000 unique sites per database server, but millions of unique visitors across all ~8000 sites on a daily basis. I've also considered removing site_id from the IP and UID indexes completely, since the chances of the same visitor going to multiple sites that share the same database server are quite small, but in cases where this does happen, I fear it could be quite slow to determine if this is a new visitor to this site_id or not. The query would be something like: select id from sessions where uid = 'value' and site_id = 123 limit 1 ... so if this visitor had visited this site before, it would only need to find one row with this site_id before it stopped. This wouldn't be super fast necessarily, but acceptably fast. But say we have a site that gets 500,000 visitors a day, and a particular visitor loves this site and goes there 10 times a day. Now they happen to hit another site on the same database server for the first time. The above query could take quite a long time to search through all of the potentially thousands of rows for this UID, scattered all over the disk, since it wouldn't be finding one for this site ID. Any insight on making this as efficient as possible would be appreciated :) Update - this is a MyISAM table with MySQL 5.0. My concerns are both with performance as well as storage space. This table is both read and write heavy. If I had to choose between performance and storage, my biggest concern is performance - but both are important. We use memcached heavily in all areas of our service, but that's not an excuse to not care about the database design. I want the database to be as efficient as possible.

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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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