Search Results

Search found 6772 results on 271 pages for 'rob effect'.

Page 252/271 | < Previous Page | 248 249 250 251 252 253 254 255 256 257 258 259  | Next Page >

• What's the best Scala build system?

  - by gatoatigrado

  I've seen questions about IDE's here -- Which is the best IDE for Scala development? and What is the current state of tooling for Scala?, but I've had mixed experiences with IDEs. Right now, I'm using the Eclipse IDE with the automatic workspace refresh option, and KDE 4's Kate as my text editor. Here are some of the problems I'd like to solve: use my own editor IDEs are really geared at everyone using their components. I like Kate better, but the refresh system is very annoying (it doesn't use inotify, rather, maybe a 10s polling interval). The reason I don't use the built-in text editor is because broken auto-complete functionalities cause the IDE to hang for maybe 10s. rebuild only modified files The Eclipse build system is broken. It doesn't know when to rebuild classes. I find myself almost half of the time going to project-clean. Worse, it seems even after it has finished building my project, a few minutes later it will pop up with some bizarre error (edit - these errors appear to be things that were previously solved with a project clean, but then come back up...). Finally, setting "Preferences / Continue launch if project contains errors" to "prompt" seems to have no effect for Scala projects (i.e. it always launches even if there are errors). build customization I can use the "nightly" release, but I'll want to modify and use my own Scala builds, not the compiler that's built into the IDE's plugin. It would also be nice to pass [e.g.] -Xprint:jvm to the compiler (to print out lowered code). fast compiling Though Eclipse doesn't always build right, it does seem snappy -- even more so than fsc. I looked at Ant and Maven, though haven't employed either yet (I'll also need to spend time solving #3 and #4). I wanted to see if anyone has other suggestions before I spend time getting a suboptimal build system working. Thanks in advance! UPDATE - I'm now using Maven, passing a project as a compiler plugin to it. It seems fast enough; I'm not sure what kind of jar caching Maven does. A current repository for Scala 2.8.0 is available [link]. The archetypes are very cool, and cross-platform support seems very good. However, about compile issues, I'm not sure if fsc is actually fixed, or my project is stable enough (e.g. class names aren't changing) -- running it manually doesn't bother me as much. If you'd like to see an example, feel free to browse the pom.xml files I'm using [github]. UPDATE 2 - from benchmarks I've seen, Daniel Spiewak is right that buildr's faster than Maven (and, if one is doing incremental changes, Maven's 10 second latency gets annoying), so if one can craft a compatible build file, then it's probably worth it...

  Read the article

• Performance Optimization for Matrix Rotation

  - by Summer_More_More_Tea

  Hello everyone: I'm now trapped by a performance optimization lab in the book "Computer System from a Programmer's Perspective" described as following: In a N*N matrix M, where N is multiple of 32, the rotate operation can be represented as: Transpose: interchange elements M(i,j) and M(j,i) Exchange rows: Row i is exchanged with row N-1-i A example for matrix rotation(N is 3 instead of 32 for simplicity): ------- ------- |1|2|3| |3|6|9| ------- ------- |4|5|6| after rotate is |2|5|8| ------- ------- |7|8|9| |1|4|7| ------- ------- A naive implementation is: #define RIDX(i,j,n) ((i)*(n)+(j)) void naive_rotate(int dim, pixel *src, pixel *dst) { int i, j; for (i = 0; i < dim; i++) for (j = 0; j < dim; j++) dst[RIDX(dim-1-j, i, dim)] = src[RIDX(i, j, dim)]; } I come up with an idea by inner-loop-unroll. The result is: Code Version Speed Up original 1x unrolled by 2 1.33x unrolled by 4 1.33x unrolled by 8 1.55x unrolled by 16 1.67x unrolled by 32 1.61x I also get a code snippet from pastebin.com that seems can solve this problem: void rotate(int dim, pixel *src, pixel *dst) { int stride = 32; int count = dim >> 5; src += dim - 1; int a1 = count; do { int a2 = dim; do { int a3 = stride; do { *dst++ = *src; src += dim; } while(--a3); src -= dim * stride + 1; dst += dim - stride; } while(--a2); src += dim * (stride + 1); dst -= dim * dim - stride; } while(--a1); } After carefully read the code, I think main idea of this solution is treat 32 rows as a data zone, and perform the rotating operation respectively. Speed up of this version is 1.85x, overwhelming all the loop-unroll version. Here are the questions: In the inner-loop-unroll version, why does increment slow down if the unrolling factor increase, especially change the unrolling factor from 8 to 16, which does not effect the same when switch from 4 to 8? Does the result have some relationship with depth of the CPU pipeline? If the answer is yes, could the degrade of increment reflect pipeline length? What is the probable reason for the optimization of data-zone version? It seems that there is no too much essential difference from the original naive version. EDIT: My test environment is Intel Centrino Duo processor and the verion of gcc is 4.4 Any advice will be highly appreciated! Kind regards!

  Read the article

• Why aren't min-width and max-width working as I expect?

  - by Nathan Long

  I'm trying to adjust a CSS page layout using min-width and max-width. To simplify the problem, I made this test page. I'm trying it out in the latest versions of Firefox and Chrome with the same results. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Testing min-width and max-width</title> <style type="text/css"> div{float: left; max-width: 400px; min-width: 200px;} div.a{background: orange;} div.b{background: gray;} </style> </head> <body> <div class="a"> (Giant block of filler text here) </div> <div class="b"> (Giant block of filler text here) </div> </body> </html> Here's what I expect to happen: With the browser maximized, the divs sit side by side, each 400px wide: their maximum width Shrink the browser window, and they both shrink to 200px: their minimum width Further shrinking the browser has no effect on them Here's what actually happens, starting at step 2: Shrink the browser window, and as soon as they can't sit side-by-side at their max width, the second div drops below the first Further shrinking the browser makes them get narrower and narrower, as small as I can make the window So here's are my questions: What does max-width mean if the element will sooner hop down in the layout than go lower than its maximum width? What does min-width mean if the element will happily get narrower than that if the browser window keeps shrinking? Is there any way to achieve what I want: have these elements sit side-by-side, happily shrinking until they reach 200px each, and only then adjust the layout so that the second one drops down? And of course... What am I doing wrong?

  Read the article

• Using multiple aggregate functions in an algebraic expression in (ANSI) SQL statement

  - by morpheous

  I have the following aggregate functions (AGG FUNCs): foo(), foobar(), fredstats(), barneystats(). I want to know if I can use multiple AGG FUNCs in an algebraic expression. This may seem a strange/simplistic question for seasoned SQL developers - however, the but the reason I ask is that so far, all AGG FUNCs examples I have seen are of the simplistic variety e.g. max(salary) < 100, rather than using the AGG FUNCs in an expression which involves using multiple AGG FUNCs in an expression (like agg_func1() agg_func2()). The information below should help clarify further. Given tables with the following schemas: CREATE TABLE item (id int, length float, weight float); CREATE TABLE item_info (item_id, name varchar(32)); # Is it legal (ANSI) SQL to write queries of this format ? SELECT id, name, foo, foobar, fredstats FROM A, B (SELECT id, foo(123) as foo, foobar('red') as foobar, fredstats('weight') as fredstats FROM item GROUP BY id HAVING [ALGEBRAIC EXPRESSION] ORDER BY id AS A), item_info AS B WHERE item.id = B.id Where: ALGEBRAIC EXPRESSION is the type of expression that can be used in a WHERE clause - for example: ((foo(x) < foobar(y)) AND foobar(y) IN (1,2,3)) OR (fredstats(x) <> 0)) I am using PostgreSQL as the db, but I would prefer to use ANSI SQL wherever possible. Assuming it is legal to include AGG FUNCS in the way I have done above, I'd like to know: Is there a more efficient way to write the above query ? Is there any way I can speed up the query in terms of a judicious choice of indexes on the tables item and item_info ? Is there a performance hit of using AGG FUNCs in an algebraic expression like I am (i.e. an expression involving the output of aggregate functions rather than constants? Can the expression also include 'scaled' AGG FUNC? (for example: 2*foo(123) < -3*foobar(456) ) - will scaling (i.e. multiplying an AGG FUNC by a number have an effect on performance?) How can I write the query above using INNER JOINS instead?

  Read the article

• Thread.CurrentThread.CurrentUICulture not working consistently

  - by xTRUMANx

  I've been working on a pet project on the weekends to learn more about C# and have encountered an odd problem when working with localization. To be more specific, the problem I have is with System.Threading.Thread.CurrentThread.CurrentUICulture. I've set up my app so that the user can quickly change the language of the app by clicking a menu item. The menu item in turn, saves the two-letter code for the language (e.g. "en", "fr", etc.) in a user setting called 'Language' and then restarts the application. Properties.Settings.Default.Language = "en"; Properties.Settings.Default.Save(); Application.Restart(); When the application is started up, the first line of code in the Form's constructor (even before InitializeComponent()) fetches the Language string from the settings and sets the CurrentUICulture like so: public Form1() { Thread.CurrentThread.CurrentUICulture = new CultureInfo(Properties.Settings.Default.Language); InitializeComponent(); } The thing is, this doesn't work consistently. Sometimes, all works well and the application loads the correct language based on the string saved in the settings file. Other times, it doesn't, and the language remains the same after the application is restarted. At first I thought that I didn't save the language before restarting the application but that is definitely not the case. When the correct language fails to load, if I were to close the application and run it again, the correct language would come up correctly. So this implies that the Language string has been saved but the CurrentUICulture assignment in my form constructor is having no effect sometimes. Any help? Is there something I'm missing of how threading works in C#? This could be machine-specific, so if it makes any difference I'm using Pentium Dual-Core CPU. UPDATE Vlad asked me to check what the CurrentThread's CurrentUICulture is. So I added a MessageBox on my constructor to tell me what the CurrentUICulture two-letter code is as well as the value of my Language user string. MessageBox.Show(string.Format("Current Language: {0}\nCurrent UI Culture: {1}", Properties.Settings.Default.Language, Thread.CurrentThread.CurrentUICulture.TwoLetterISOLanguageName)); When the wrong language is loaded, both the Language string and CurrentUICulture have the wrong language. So I guess the CurrentUICulture has been cleared and my problem is actually with the Language Setting. So I guess the problem is that my application sometimes loads the previously saved language string rather than the last saved language string. If the app is restarted, it will then load the actual saved language string.

  Read the article

• C# Extend array type to overload operators

  - by Episodex

  I'd like to create my own class extending array of ints. Is that possible? What I need is array of ints that can be added by "+" operator to another array (each element added to each), and compared by "==", so it could (hopefully) be used as a key in dictionary. The thing is I don't want to implement whole IList interface to my new class, but only add those two operators to existing array class. I'm trying to do something like this: class MyArray : Array<int> But it's not working that way obviously ;). Sorry if I'm unclear but I'm searching solution for hours now... UPDATE: I tried something like this: class Zmienne : IEquatable<Zmienne> { public int[] x; public Zmienne(int ilosc) { x = new int[ilosc]; } public override bool Equals(object obj) { if (obj == null || GetType() != obj.GetType()) { return false; } return base.Equals((Zmienne)obj); } public bool Equals(Zmienne drugie) { if (x.Length != drugie.x.Length) return false; else { for (int i = 0; i < x.Length; i++) { if (x[i] != drugie.x[i]) return false; } } return true; } public override int GetHashCode() { int hash = x[0].GetHashCode(); for (int i = 1; i < x.Length; i++) hash = hash ^ x[i].GetHashCode(); return hash; } } Then use it like this: Zmienne tab1 = new Zmienne(2); Zmienne tab2 = new Zmienne(2); tab1.x[0] = 1; tab1.x[1] = 1; tab2.x[0] = 1; tab2.x[1] = 1; if (tab1 == tab2) Console.WriteLine("Works!"); And no effect. I'm not good with interfaces and overriding methods unfortunately :(. As for reason I'm trying to do it. I have some equations like: x1 + x2 = 0.45 x1 + x4 = 0.2 x2 + x4 = 0.11 There are a lot more of them, and I need to for example add first equation to second and search all others to find out if there is any that matches the combination of x'es resulting in that adding. Maybe I'm going in totally wrong direction?

  Read the article

• jquery ui autocomplete does't close options menu if there is no focus when ajax returns

  - by Uri

  I'm using jquery ui autocomplete widget with ajax, and on noticed the following problem. Background: In order for the user to be able to focus on the autocomplete and get the options without typing anything, I use the focus event: autoComp.focus(function() { $(this).autocomplete("search", "");} However this produces the following effect: when the user clicks, an ajax request is being sent. While waiting for the response, the user then clicks elsewhere and the autocomplete is blurred. But as soon as the response returns, the options menu pops out, even though the autocomplete has no focus. In order to make it go away the user has to click once inside, and again outside the autocomplete, which is a bit annoying. any ideas how I prevent this? EDIT: I solved this in a very ugly way by building another mediator function that knows the element's ID, and this function calls the ajax function with the ID, which on success check the focus of the element, and returns null if it's not focused. It's pretty ugly and I'm still looking for alternatives. EDIT#2: Tried to do as Wlliam suggested, still doesn't work.. the xhr is undefined when blurring. Some kind of a problem with the this keyword, maybe it has different meanings if I write the getTags function outside of the autocomplete? this.autocomplete = $('.tab#'+this.id+' #tags').autocomplete({ minLength: 0, autoFocus: true, source: getTags, select: function(e, obj) { tab_id = $(this).parents('.tab').attr('id'); tabs[tab_id].addTag(obj.item.label, obj.item.id, false); $(this).blur(); // This is done so that the options menu won't pop up again. return false; // This is done so that the value will not stay in the input box after selection. }, open: function() {}, close: function() {} }); $('.tab#'+this.id+' #tags').focus(function() { $(this).autocomplete("search", ""); }); $('.tab#'+this.id+' #tags').blur(function() { console.log('blurring'); var xhr = $(this).data('xhr'); // This comes out undefined... :( if (xhr) { xhr.abort(); }; $(this).removeClass('ui-autocomplete-loading'); }); and this is the getTags function copied to the source keyword: function getTags(request, response) { console.log('Getting tags.'); $(this).data('xhr', $.ajax({ url: '/rpc', dataType: 'json', data: { action: 'GetLabels', arg0: JSON.stringify(request.term) }, success: function(data) { console.log('Tags arrived:'); tags = []; for (i in data) { a = {} a.id = data[i]['key']; a.label = data[i]['name']; tags.push(a); } response(tags); } })); console.log($(this).data('xhr')); }

  Read the article

• CSS Rollovers: how to maintain "hit area" size when hidden image is larger than anchor area

  - by nukefusion

  I have a small problem and I don't think what I want to do can be achieved with just pure CSS, but I figured I'd ask anyway. Basically, I have one DIV which contains a hyperlinked element that is smaller in size to it's parent DIV. So in effect I have a square within a square with the inner square being the "hit area". When I mouse over this inner square I want the background of the outer square to change. I know it's not possible to change the parent DIV's background on a:hover, but I figured I could give the illusion of it happening by nesting a hidden image inside the anchor. This works great until I want to "roll off". The problem is that I want the image to disappear when I leave the area of the anchor tag, not the larger hidden image. Is this possible? For the benefit of everyone I've provided an example to demonstrate what I mean: <!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> <meta content="text/html; charset=utf-8" http-equiv="Content-Type" /> <title>Test Rollover</title> <link href="main.css" rel="stylesheet" type="text/css" /> </head> <body> <div id="d1"> <a href="#nogo"> <b id="b1"></b> <b id="b2"></b> </a> </div> </body> And the css: #b1 { width: 200px; height: 200px; top: 100px; left: 100px; background-color:aqua; position: absolute; z-index: 100; } #b2 { width: 400px; height: 400px; background-color:lime; position: absolute; display: none; z-index: 90; } #d1 { width: 400px; height: 400px; background-color:fuchsia; position: relative; } #d1 a:hover #b2 { display: block; } In this example I want the green outer square to disappear when I leave the bounds of the hidden inner blue square.

  Read the article

• show/hide html table columns using css

  - by Art Peterson

  I want to display a basic html table with controls to toggle showing/hiding of additional columns: <table id="mytable"> <tr> <th>Column 1</th> <th class="col1">1a</th> <th class="col1">1b</th> <th>Column 2</th> <th class="col2">2a</th> <th class="col2">2b</th> </tr> <tr> <td>100</td> <td class="col1">40</td> <td class="col1">60</td> <td>200</td> <td class="col2">110</td> <td class="col2">90</td> </tr> </table> So Column 1 and Column 2 will be the only columns displayed by default - but when you click on the Column 1 I want 1a and 1b to toggle, and same with Column 2 with 2a and 2b. I may end up with more columns and lots of rows - so any javascript looping approaches have been too slow to work with when I tested. The only approach that seems to be fast enough is to set up some css like this: table.hide1 .col1 { display: none; } table.hide2 .col2 { display: none; } table.hide3 .col3 { display: none; } table.show1 .col1 { display: table-cell; } table.show2 .col2 { display: table-cell; } table.show3 .col3 { display: table-cell; } And then set up onClick function calls on the table header cells that will trigger a toggle - and determine which css class to set "mytable" to that will create the toggle effect that I'm looking for. Is there an easy way to set this up so that the code can work for n # of columns?

  Read the article

• When does IE7 recompute styles? Doesn't work reliably when a class is added to the body.

  - by Kid A

  I have an interesting problem here. I'm using a class on the element as a switch to drive a fair amount of layout behavior on my site. If the class is applied, certain things happen, and if the class isn't applied, they don't happen. The relevant CSS is roughly like this: .rightSide { display:none; } .showCommentsRight .rightSide { display:block; width:50%; } .showCommentsRight .leftSide { display:block; width:50%; } And the HTML: <body class="showCommentsRight"> <div class="container"></div> <div class="leftSide"></div> <div class="rightSide"></div> </div> <div class="container"></div> <div class="leftSide"></div> <div class="rightSide"></div> </div> <div class="container"></div> <div class="leftSide"></div> <div class="rightSide"></div> </div> </body> I've simplified things but this is essentially the method. The whole page changes layout (hiding the right side in three different areas) when the flag is set on the body. This works in Firefox and IE8. It does not work in IE8 in compatibility mode. What is fascinating is that if you sit there and refresh the page, the results can vary. It will pick a different section's right side to show. Sometimes it will show only the top section's right side, sometimes it will show the middle. I have tried a validator (to look for malformed html), double css formatting, and making sure my IE7 hack sheet wasn't having an effect. So my question is: * Is there a way that this behavior can be made reliable? * When does IE7 decide to re-do styling? Thanks everyone.

  Read the article

• CSS3's border-radius property and border-collapse:collapse don't mix. How can I use border-radius to

  - by vamin

  Edit - Original Title: Is there an alternative way to achieve border-collapse:collapse in CSS (in order to have a collapsed, rounded corner table)? Since it turns out that simply getting the table's borders to collapse does not solve the root problem, I have updated the title to better reflect the discussion. I am trying to make a table with rounded corners using the CSS3 border-radius property. The table styles I'm using look something like this: table { -moz-border-radius:10px; -webkit-border-radius:10px; border-radius:10px} Here's the problem. I also want to set the border-collapse:collapse property, and when that is set border-radius no longer works (at least in Firefox)(edit- I thought this might just be a difference in mozilla's implementation, but it turns out this is the way it's supposed to work according to the w3c). Is there a CSS-based way I can get the same effect as border-collapse:collapse without actually using it? Edits: I've made a simple page to demonstrate the problem here (Firefox/Safari only). It seems that a large part of the problem is that setting the table to have rounded corners does not affect the corners of the corner td elements. If the table was all one color, this wouldn't be a problem since I could just make the top and bottom td corners rounded for the first and last row respectively. However, I am using different background colors for the table to differentiate the headings and for striping, so the inner td elements would show their rounded corners as well. Summary of proposed solutions: Surrounding the table with another element with round corners doesn't work because the table's square corners "bleed through." Specifying border width to 0 doesn't collapse the table. Bottom td corners still square after setting cellspacing to zero. Using javascript instead- works by avoiding the problem. Possible solutions: The tables are generated in php, so I could just apply a different class to each of the outer th/tds and style each corner separately. I'd rather not do this, since it's not very elegant and a bit of a pain to apply to multiple tables, so please keep suggestions coming. Possible solution 2 is to use javascript (jQuery, specifically) to style the corners. This solution also works, but still not quite what I'm looking for (I know I'm picky). I have two reservations: 1) this is a very lightweight site, and I'd like to keep javascript to the barest minimum 2) part of the appeal that using border-radius has for me is graceful degradation and progressive enhancement. By using border-radius for all rounded corners, I hope to have a consistently rounded site in CSS3-capable browsers and a consistently square site in others (I'm looking at you, IE). I know that trying to do this with CSS3 today may seem needless, but I have my reasons. I would also like to point out that this problem is a result of the w3c speficication, not poor CSS3 support, so any solution will still be relevant and useful when CSS3 has more widespread support.

  Read the article

• Need help with auto-scaffolding template in ASP.NET MVC

  - by DanM

  I'm trying to write an auto-scaffolder for Index views. I'd like to be able to pass in a collection of models or view-models (e.g., IQueryable<MyViewModel>) and get back an HTML table that uses the DisplayName attribute for the headings (th elements) and Html.Display(propertyName) for the cells (td elements). Each row should correspond to one item in the collection. Here's what I have so far: <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %> <% var items = (IQueryable<TestProj.ViewModels.TestViewModel>)Model; // Should be generic! var properties = items.First().GetMetadata().Properties .Where(pm => pm.ShowForDisplay && !ViewData.TemplateInfo.Visited(pm)); %> <table> <tr> <% foreach(var property in properties) { %> <th> <%= property.DisplayName %> </th> <% } %> </tr> <% foreach(var item in items) { %> <tr> <% foreach(var property in properties) { %> <td> <%= Html.Display(property.DisplayName) %> // This doesn't work! </td> <% } %> </tr> <% } %> </table> Two problems with this: I'd like it to be generic. So, I'd like to replace var items = (IQueryable<TestProj.ViewModels.TestViewModel>)Model; with var items = (IQueryable<T>)Model; or something to that effect. The <td> elements are not working because the Html in <%= Html.Display(property.DisplayName) %> contains the model for the view, which is a collection of items, not the item itself. Somehow, I need to obtain an HtmlHelper object whose Model property is the current item, but I'm not sure how to do that. How do I solve these two problems?

  Read the article

• Show/Hide button (text) for Accordion

  - by Kevin

  Have an accordion with a "view" button to open close the accordion panel (using jQuery Tools), but I would like to have dynamic text that says "show/hide" depending on the state... Here is the code for the accordion in asp.NET <div id="accordion"> <% foreach (var eventModel in ViewModel) { %> <% var isNewMonth = eventModel.Date.Month != previousMonth; %> <% if (isNewMonth && previousMonth > 0) { %></table></div><% } %> <% previousMonth = eventModel.Date.Month; %> <% if (isNewMonth) { %> <h2><%= string.Concat(eventModel.Date.ToString("MMMM"), " ", eventModel.Date.Year) %> <span style="float:right;"><a href="#" class="button blue small">View</a></span></h2> <div class="pane" style="display:block"> <table id="listTable" width="100%" cellpadding="3" cellspacing="0" border="0"> <tr align="left" valign="top"><th align="left" valign="top">Date</th><th align="left" valign="top">Event</th><th align="left" valign="top">Event Type</th></tr> <% } %> <tr align="left" valign="top"><td align="left" valign="top"><b><span id="date" style="float:left;"> <%= string.Concat(eventModel.Date.ToString("MMMM"), " ", eventModel.Date.Day, " </span><span id='day' style='float:left'>" + eventModel.Date.DayOfWeek + "</span> ")%></b></td><td align="left" valign="top" ><%= Html.ActionLink(eventModel.Name.Truncate(40), "event", "register", new { id = eventModel.Id }, null)%></td><td align="left" valign="top"><%= string.Concat(" ", eventModel.Sport)%></td></tr> <% } %> <% if (ViewModel.Count > 0) { %></table></div><% } %> </div> Here is the initialization script using jQuery: $(function() { $("#accordion").tabs("#accordion div.pane", {tabs: 'h2', effect: 'slide', initialIndex: 0}); $(".small").click(function() { moveToTop(); }); });

  Read the article

• Hibernate Communications Link Failure in Hibernate Based Java Servlet application powered by MySQL

  - by Vatsala

  Let me describe my question - I have a Java application - Hibernate as the DB interfacing layer over MySQL. I get the communications link failure error in my application. The occurence of this error is a very specific case. I get this error , When I leave mysql server unattended for more than approximately 6 hours (i.e. when there are no queries issued to MySQL for more than approximately 6 hours). I am pasting a top 'exception' level description below, and adding a pastebin link for a detailed stacktrace description. javax.persistence.PersistenceException: org.hibernate.exception.JDBCConnectionException: Cannot open connection - Caused by: org.hibernate.exception.JDBCConnectionException: Cannot open connection - Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure - The last packet successfully received from the server was 1,274,868,181,212 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago. - Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure - The last packet successfully received from the server was 1,274,868,181,212 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago. - Caused by: java.net.ConnectException: Connection refused: connect the link to the pastebin for further investigation - http://pastebin.com/4KujAmgD What I understand from these exception statements is that MySQL is refusing to take in any connections after a period of idle/nil activity. I have been reading up a bit about this via google search, and came to know that one of the possible ways to overcome this is to set values for c3p0 properties as c3p0 comes bundled with Hibernate. Specifically, I read from here http://www.mchange.com/projects/c3p0/index.html that setting two properties idleConnectionTestPeriod and preferredTestQuery will solve this for me. But these values dont seem to have had an effect. Is this the correct approach to fixing this? If not, what is the right way to get over this? The following are related Communications Link Failure questions at stackoverflow.com, but I've not found a satisfactory answer in their answers. http://stackoverflow.com/questions/2121829/java-db-communications-link-failure http://stackoverflow.com/questions/298988/how-to-handle-communication-link-failure Note 1 - i dont get this error when I am using my application continuosly. Note 2 - I use JPA with Hibernate and hence my hibernate.dialect,etc hibernate properties reside within the persistence.xml in the META-INF folder (does that prevent the c3p0 properties from working?) edit - Here are the c3p0 parameters I tried out - select 1; 2

  Read the article

• Cross-thread operation not valid: Control accessed from a thread other than the thread it was create

  - by SilverHorse

  I have a scenario. (Windows Forms, C#, .NET) There is a main form which hosts some user control. The user control does some heavy data operation, such that if I directly call the Usercontrol_Load method the UI become nonresponsive for the duration for load method execution. To overcome this I load data on different thread (trying to change existing code as little as I can) I used a background worker thread which will be loading the data and when done will notify the application that it has done its work. Now came a real problem. All the UI (main form and its child usercontrols) was created on the primary main thread. In the LOAD method of the usercontrol I'm fetching data based on the values of some control (like textbox) on userControl. The pseudocode would look like this: //CODE 1 UserContrl1_LOadDataMethod() { if(textbox1.text=="MyName") <<======this gives exception { //Load data corresponding to "MyName". //Populate a globale variable List<string> which will be binded to grid at some later stage. } } The Exception it gave was Cross-thread operation not valid: Control accessed from a thread other than the thread it was created on. To know more about this I did some googling and a suggestion came up like using the following code //CODE 2 UserContrl1_LOadDataMethod() { if(InvokeRequired) // Line #1 { this.Invoke(new MethodInvoker(UserContrl1_LOadDataMethod)); return; } if(textbox1.text=="MyName") //<<======Now it wont give exception** { //Load data correspondin to "MyName" //Populate a globale variable List<string> which will be binded to grid at some later stage } } BUT BUT BUT... it seems I'm back to square one. The Application again become nonresponsive. It seems to be due to the execution of line #1 if condition. The loading task is again done by the parent thread and not the third that I spawned. I don't know whether I perceived this right or wrong. I'm new to threading. How do I resolve this and also what is the effect of execution of Line#1 if block? The situation is this: I want to load data into a global variable based on the value of a control. I don't want to change the value of a control from the child thread. I'm not going to do it ever from a child thread. So only accessing the value so that the corresponding data can be fetched from the database.

  Read the article

• Symfony : ajax call cause server to queue next queries

  - by Remiz

  Hello, I've a problem with my application when an ajax call on the server takes too much time : it queue all the others queries from the user until it's done server side (I realized that canceling the call client side has no effect and the user still have to wait). Here is my test case : <script type="text/javascript" src="jquery-1.4.1.min.js"></script> <a href="another-page.php">Go to another page on the same server</a> <script type="text/javascript"> url = 'http://localserver/some-very-long-complex-query'; $.get(url); </script> So when the get is fired and then after I click on the link, the server finish serving the first call before bringing me to the other page. My problem is that I want to avoid this behavior. I'm on a LAMP server and I'm looking in a way to inform the server that the user aborted the query with function like connection_aborted(), do you think that's the way to go ? Also, I know that the longest part of this PHP script is a MySQL query, so even if I know that connection_aborted() can detect that the user cancel the call, I still need to check this during the MySQL query... I'm not really sure that PHP can handle this kind of "event". So if you have any better idea, I can't wait to hear it. Thank you. Update : After further investigation, I found that the problem happen only with the Symfony framework (that I omitted to precise, my bad). It seems that an Ajax call lock any other future call. It maybe related to the controller or the routing system, I'm looking into it. Also for those interested by the problem here is my new test case : -new project with Symfony 1.4.3, default configuration, I just created an app and a default module. -jquery 1.4 for the ajax query. Here is my actions.class.php (in my unique module) : class defaultActions extends sfActions { public function executeIndex(sfWebRequest $request) { //Do nothing } public function executeNewpage() { //Do also nothing } public function executeWaitingaction(){ // Wait sleep(30); return false; } } Here is my indexSuccess.php template file : <script type="text/javascript" src="jquery-1.4.1.min.js"></script> <a href="<?php echo url_for('default/newpage');?>">Go to another symfony action</a> <script type="text/javascript"> url = '<?php echo url_for('default/waitingaction');?>'; $.get(url); </script> For the new page template, it's not very relevant... But with this, I'm able to reproduce the lock problem I've on my real application. Is somebody else having the same issue ? Thanks.

  Read the article

• measure rendered html in javascript without affecting the measurement

  - by drawnonward

  I am doing pagination in javascript. This is typographic pagination, not chopping up database results. For the most part it works, but I have run into a heisenberg issue where I cannot quite measure text without affecting it. I am not trying to measure text before it is rendered. I want the actual position it shows up at on screen, so I can paginate to where it is naturally wrapped. I am measuring the vertical position of characters, not the horizontal width of strings. The way I do this is similar to this answer in that I am applying a style to a block of text, then measuring the position of the newly created span. If the span does not reach the end of the page, I clear it and make a new span in a linear search. The problem is that the anti-aliased sub-pixel text layout is different when the span is applied. In rare cases, this causes the text to wrap differently when I measure it. I have only seen this when wrapping at a hyphen, and I assume it would not happen when wrapping at white space. As a concrete example, "prepared-he" is the string I am having trouble with. When I measure up to "prepare" it appears, as expected, to be within the current page. When I measure "prepared" the whole phrase wraps down to the next line, moving it to the next page, so it looks like the "d" is the character to break at. I break the text between "prepare" and "d-he" and that is wrong. Trying to evaluate individual characters opens a whole can of worms I would rather avoid. The wrapping changes because, with the new span, the line is 1 pixel wider. A solution to my problem could either be a better way to measure text using javascript, or a way to wrap text in a new element without affecting layout. I have tried setting margin-right:-1px for the class of the span being created to wrap the text. This had no noticeable effect. I am doing this in a UIWebView on the iPhone. There are some measurement related calls that are available in normal WebKit that are not available here. For example, Range does not have getBoundingClientRect or support setting an offset other than 0 in setStart or setEnd. Thank you

  Read the article

• Hotfixing Code running inside Web Container with Groovy

  - by raoulsson

  I have a webapp running that has a bug. I know how to fix it in the sources. However I cannot redeploy the app as I would have to take it offline to do so. (At least not right now). I now want to fix the code "at runtime". Surgery on the living object, so to speak. The app is implemented in Java and is build on top of Seam. I have added a Groovy Console to the app previous to the last release. (A way to run arbitrary code at runtime) The normal way of adding behaviour to a class with Groovy would be similar to this: String.metaClass.foo= { x -> x * x } println "anything".foo(3) This code added the method foo to java.lang.String and prints 9. I can do the same thing with classes running inside my webapp container. New instances will thereafter show the same behaviour: com.my.package.SomeService.metaClass.foo= { x -> x * x } def someService = new com.my.package.SomeService() println someService.foo(3) Works as excpected. All good so far. My problem is now that the container, the web framework, Seam in this case, has already instantiated and cached the classes that I would like to manipulate (that is change their behaviour to reflect my bug fix). Ideally this code would work: com.my.package.SomeService.metaClass.foo= { x -> x * x } def x = org.jboss.seam.Component.getInstance(com.my.package.SomeService) println x.foo(3) However the instantiation of SomeService has already happened and there is no effect. Thus I need a way to make my changes "sticky". Has the groovy magic gone after my script has been run? Well, after logging out and in again, I can run this piece of code and get the expected result: def someService = new com.my.package.SomeService() println someService.foo(3) So the foo method is still around and it looks like my change has been permanent... So I guess the question that remains is how to force Seam to re-instantiate all its components and/or how to permanently make the change on all living instances...?

  Read the article

• Simplest way to flatten document to a view in RavenDB

  - by degorolls

  Given the following classes: public class Lookup { public string Code { get; set; } public string Name { get; set; } } public class DocA { public string Id { get; set; } public string Name { get; set; } public Lookup Currency { get; set; } } public class ViewA // Simply a flattened version of the doc { public string Id { get; set; } public string Name { get; set; } public string CurrencyName { get; set; } // View just gets the name of the currency } I can create an index that allows client to query the view as follows: public class A_View : AbstractIndexCreationTask<DocA, ViewA> { public A_View() { Map = docs => from doc in docs select new ViewA { Id = doc.Id, Name = doc.Name, CurrencyName = doc.Currency.Name }; Reduce = results => from result in results group on new ViewA { Id = result.Id, Name = result.Name, CurrencyName = result.CurrencyName } into g select new ViewA { Id = g.Key.Id, Name = g.Key.Name, CurrencyName = g.Key.CurrencyName }; } } This certainly works and produces the desired result of a view with the data transformed to the structure required at the client application. However, it is unworkably verbose, will be a maintenance nightmare and is probably fairly inefficient with all the redundant object construction. Is there a simpler way of creating an index with the required structure (ViewA) given a collection of documents (DocA)? FURTHER INFORMATION The issue appears to be that in order to have the index hold the data in the transformed structure (ViewA), we have to do a Reduce. It appears that a Reduce must have both a GROUP ON and a SELECT in order to work as expected so the following are not valid: INVALID REDUCE CLAUSE 1: Reduce = results => from result in results group on new ViewA { Id = result.Id, Name = result.Name, CurrencyName = result.CurrencyName } into g select g.Key; This produces: System.InvalidOperationException: Variable initializer select must have a lambda expression with an object create expression Clearly we need to have the 'select new'. INVALID REDUCE CLAUSE 2: Reduce = results => from result in results select new ViewA { Id = result.Id, Name = result.Name, CurrencyName = result.CurrencyName }; This prduces: System.InvalidCastException: Unable to cast object of type 'ICSharpCode.NRefactory.Ast.IdentifierExpression' to type 'ICSharpCode.NRefactory.Ast.InvocationExpression'. Clearly, we also need to have the 'group on new'. Thanks for any assistance you can provide. (Note: removing the type (ViewA) from the constructor calls has no effect on the above)

  Read the article

• Windows splash screen using GDI+

  - by Luther

  The eventual aim of this is to have a splash screen in windows that uses transparency but that's not what I'm stuck on at the moment. In order to create a transparent window, I'm first trying to composite the splash screen and text on an off screen buffer using GDI+. At the moment I'm just trying to composite the buffer and display it in response to a 'WM_PAINT' message. This isn't working out at the moment; all I see is a black window. I imagine I've misunderstood something with regards to setting up render targets in GDI+ and then rendering them (I'm trying to render the screen using straight forward GDI blit) Anyway, here's the code so far: //my window initialisation code void MyWindow::create_hwnd(HINSTANCE instance, const SIZE &dim) { DWORD ex_style = WS_EX_LAYERED ; //eventually I'll be making use of this layerd flag m_hwnd = CreateWindowEx( ex_style, szFloatingWindowClass , L"", WS_POPUP , 0, 0, dim.cx, dim.cy, null, null, instance, null); SetWindowLongPtr(m_hwnd ,0, (__int3264)(LONG_PTR)this); m_display_dc = GetDC(NULL); //This was sanity check test code - just loading a standard HBITMAP and displaying it in WM_PAINT. It worked fine //HANDLE handle= LoadImage(NULL , L"c:\\test_image2.bmp", IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE); m_gdip_offscreen_bm = new Gdiplus::Bitmap(dim.cx, dim.cy); m_gdi_dc = Gdiplus::Graphics::FromImage(m_gdip_offscreen_bm);//new Gdiplus::Graphics(m_splash_dc );//window_dc ;m_splash_dc //this draws the conents of my splash screen - this works if I create a GDI+ context for the window, rather than for an offscreen bitmap. //For all I know, it might actually be working but when I try to display the contents on screen, it shows a black image draw_all(); //this is just to show that drawing something simple on the offscreen bit map seems to have no effect Gdiplus::Pen pen(Gdiplus::Color(255, 0, 0, 255)); m_gdi_dc->DrawLine(&pen, 0,0,100,100); DWORD last_error = GetLastError(); //returns '0' at this stage } And here's the snipit that handles the WM_PAINT message: ---8<----------------------- //Paint message snippit case WM_PAINT: { BITMAP bm; PAINTSTRUCT ps; HDC hdc = BeginPaint(vg->m_hwnd, &ps); //get the HWNDs DC HDC hdcMem = vg->m_gdi_dc->GetHDC(); //get the HDC from our offscreen GDI+ object unsigned int width = vg->m_gdip_offscreen_bm->GetWidth(); //width and height seem fine at this point unsigned int height = vg->m_gdip_offscreen_bm->GetHeight(); BitBlt(hdc, 0, 0, width, height, hdcMem, 0, 0, SRCCOPY); //this blits a black rectangle DWORD last_error = GetLastError(); //this was '0' vg->m_gdi_dc->ReleaseHDC(hdcMem); EndPaint(vg->m_hwnd, &ps); //end paint return 1; } ---8<----------------------- My apologies for the long post. Does anybody know what I'm not quite understanding regarding how you write to an offscreen buffer using GDI+ (or GDI for that matter)and then display this on screen? Thank you for reading.

  Read the article

• CSS RGBA border / background alpha double

  - by stockli

  I'm working on a website that has a lot of transparency involved, and I thought I would try to build it entirely in RGBA and then do fallbacks for IE. I need a "facebox" style border effect, where the outer border is rounded and is less opaque than the background of the box it surrounds. The last example from http://24ways.org/2009/working-with-rgba-colour seems to suggest that it's possible, but I can't seem to get it to work. When I try the following: <!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" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/> <title>RGBA Test</title> <style type='text/css'> body { background: #000; color: #fff; } #container { width: 700px; margin: 0 auto; background: rgba(255, 255, 255, 0.2); border: 10px solid rgba(255, 255, 255, 0.1); padding: 20px; } </style> </head> <body> <div id='container'> This should look like a facebox. </div> </body></html> It seems like the background "extends" underneath the border of the element, which causes the pixel values to get added together. Thus, when both the background and the border are semi-transparent, the border will ALWAYS be more opaque than the background of the element. This is exactly the opposite of what I am trying to achieve, but it seems like it should be possible based on the examples I've seen. I should also add that I can't use another element inside the container, because I'm also going to use a border-radius on the container to get rounded corners, and webkit squares the corners of the child elements if they have a background assigned, which would essentially mean a rounded outer border with square contents. Sorry I can't post an image of this... Apparently I don't have enough rep to post an image.

  Read the article

• c++ quick sort running time

  - by chnet

  I have a question about quick sort algorithm. I implement quick sort algorithm and play it. The elements in initial unsorted array are random numbers chosen from certain range. I find the range of random number effects the running time. For example, the running time for 1, 000, 000 random number chosen from the range (1 - 2000) takes 40 seconds. While it takes 9 seconds if the 1,000,000 number chosen from the range (1 - 10,000). But I do not know how to explain it. In class, we talk about the pivot value can effect the depth of recursion tree. For my implementation, the last value of the array is chosen as pivot value. I do not use randomized scheme to select pivot value. int partition( vector<int> &vec, int p, int r) { int x = vec[r]; int i = (p-1); int j = p; while(1) { if (vec[j] <= x){ i = (i+1); int temp = vec[j]; vec[j] = vec[i]; vec[i] = temp; } j=j+1; if (j==r) break; } int temp = vec[i+1]; vec[i+1] = vec[r]; vec[r] = temp; return i+1; } void quicksort ( vector<int> &vec, int p, int r) { if (p<r){ int q = partition(vec, p, r); quicksort(vec, p, q-1); quicksort(vec, q+1, r); } } void random_generator(int num, int * array) { srand((unsigned)time(0)); int random_integer; for(int index=0; index< num; index++){ random_integer = (rand()%10000)+1; *(array+index) = random_integer; } } int main() { int array_size = 1000000; int input_array[array_size]; random_generator(array_size, input_array); vector<int> vec(input_array, input_array+array_size); clock_t t1, t2; t1 = clock(); quicksort(vec, 0, (array_size - 1)); // call quick sort int length = vec.size(); t2 = clock(); float diff = ((float)t2 - (float)t1); cout << diff << endl; cout << diff/CLOCKS_PER_SEC <<endl; }

  Read the article

• Struggling with ASP.NET MVC auto-scaffolder template

  - by DanM

  I'm trying to write an auto-scaffolder template for Index views. I'd like to be able to pass in a collection of models or view-models (e.g., IQueryable<MyViewModel>) and get back an HTML table that uses the DisplayName attribute for the headings (th elements) and Html.Display(propertyName) for the cells (td elements). Each row should correspond to one item in the collection. Here's what I have so far: <%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl" %> <% var items = (IQueryable<TestProj.ViewModels.TestViewModel>)Model; // How do I make this generic? var properties = items.First().GetMetadata().Properties .Where(pm => pm.ShowForDisplay && !ViewData.TemplateInfo.Visited(pm)); %> <table> <tr> <% foreach(var property in properties) { %> <th> <%= property.DisplayName %> </th> <% } %> </tr> <% foreach(var item in items) { HtmlHelper itemHtml = ????; // What should I put in place of "????"? %> <tr> <% foreach(var property in properties) { %> <td> <%= itemHtml.Display(property.DisplayName) %> </td> <% } %> </tr> <% } %> </table> Two problems with this: I'd like it to be generic. So, I'd like to replace var items = (IQueryable<TestProj.ViewModels.TestViewModel>)Model; with var items = (IQueryable<T>)Model; or something to that effect. A property Html is automatically created for me when the view is created, but this HtmlHelper applies to the whole collection. I need to somehow create an itemHtml object that applies just to the current item in the foreach loop. I'm not sure how to do this, however, because the constructors for HtmlHelper don't take a Model object. How do I solve these two problems?

  Read the article

• How does Sentry aggregate errors?

  - by Hugo Rodger-Brown

  I am using Sentry (in a django project), and I'd like to know how I can get the errors to aggregate properly. I am logging certain user actions as errors, so there is no underlying system exception, and am using the culprit attribute to set a friendly error name. The message is templated, and contains a common message ("User 'x' was unable to perform action because 'y'"), but is never exactly the same (different users, different conditions). Sentry clearly uses some set of attributes under the hood to determine whether to aggregate errors as the same exception, but despite having looked through the code, I can't work out how. Can anyone short-cut my having to dig further into the code and tell me what properties I need to set in order to manage aggregation as I would like? [UPDATE 1: event grouping] This line appears in sentry.models.Group: class Group(MessageBase): """ Aggregated message which summarizes a set of Events. """ ... class Meta: unique_together = (('project', 'logger', 'culprit', 'checksum'),) ... Which makes sense - project, logger and culprit I am setting at the moment - the problem is checksum. I will investigate further, however 'checksum' suggests that binary equivalence, which is never going to work - it must be possible to group instances of the same exception, with differenct attributes? [UPDATE 2: event checksums] The event checksum comes from the sentry.manager.get_checksum_from_event method: def get_checksum_from_event(event): for interface in event.interfaces.itervalues(): result = interface.get_hash() if result: hash = hashlib.md5() for r in result: hash.update(to_string(r)) return hash.hexdigest() return hashlib.md5(to_string(event.message)).hexdigest() Next stop - where do the event interfaces come from? [UPDATE 3: event interfaces] I have worked out that interfaces refer to the standard mechanism for describing data passed into sentry events, and that I am using the standard sentry.interfaces.Message and sentry.interfaces.User interfaces. Both of these will contain different data depending on the exception instance - and so a checksum will never match. Is there any way that I can exclude these from the checksum calculation? (Or at least the User interface value, as that has to be different - the Message interface value I could standardise.) [UPDATE 4: solution] Here are the two get_hash functions for the Message and User interfaces respectively: # sentry.interfaces.Message def get_hash(self): return [self.message] # sentry.interfaces.User def get_hash(self): return [] Looking at these two, only the Message.get_hash interface will return a value that is picked up by the get_checksum_for_event method, and so this is the one that will be returned (hashed etc.) The net effect of this is that the the checksum is evaluated on the message alone - which in theory means that I can standardise the message and keep the user definition unique. I've answered my own question here, but hopefully my investigation is of use to others having the same problem. (As an aside, I've also submitted a pull request against the Sentry documentation as part of this ;-)) (Note to anyone using / extending Sentry with custom interfaces - if you want to avoid your interface being use to group exceptions, return an empty list.)

  Read the article

• LinearLayout as custom button, OnClickListener never called

  - by ohra

  I've been using the common Android Button with both icon (drawableTop) and text. It works really poorly if you want to have a non-standard size button, so I decided to make a custom button with a LinearLayout having the following layout: <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" style="@style/ButtonHoloDark" android:layout_width="fill_parent" android:layout_height="fill_parent" android:gravity="center" android:clickable="true" android:focusable="true" android:orientation="vertical" > <ImageView android:id="@+id/buttonIcon" android:layout_width="fill_parent" android:layout_height="wrap_content" android:duplicateParentState="true" /> <TextView android:id="@+id/buttonText" android:layout_width="fill_parent" android:layout_height="wrap_content" android:duplicateParentState="true" android:gravity="center" android:textColor="@color/white" /> </LinearLayout> The layout is used by a custom class: public class CustomIconButton extends LinearLayout { public CustomIconButton(Context context, AttributeSet attrs) { super(context, attrs); setAttributes(context, attrs); LayoutInflater.from(context).inflate(R.layout.custom_icon_button, this, true); } ... But when I set an OnClickListener on my button in its parent layout it never gets called. I can only receive clicks if a set the listener to the ImageView and/or TextView. This leads to two possible effects when the button is clicked: The click is inside the ImageView or the TextView. The click is registered ok, but the buttons state drawable doesn't change i.e. it doesn't appear depressed. The click is inside the "empty area" of the button. The click is not registered, but the state drawable works ok. Neither of these is feasible. I've played around with the following attributes on the LinearLayout or its children, but none really seem to have any effect whether true or false: duplicateParentState clickable focusable There doesn't seem to be any reasonable way to get the LinearLayout parent receive clicks instead of its children. I've seen some possible solutions overriding dispatchTouchEvent or onInterceptTouchEvent on the custom component itself, but that really seems like a big mess if I have to start analyzing touch events to identify proper clicks. So OnClickListener on a LinearLayout with children = no go?

  Read the article

< Previous Page | 248 249 250 251 252 253 254 255 256 257 258 259  | Next Page >