Search Results

Search found 12397 results on 496 pages for 'maybe'.

Page 481/496 | < Previous Page | 477 478 479 480 481 482 483 484 485 486 487 488  | Next Page >

• What is "elegant" code?

  - by Breton

  I see a lot of lip service and talk about the most "elegant" way to do this or that. I think if you spend enough time programming you begin to obtain a sort of intuitive feel for what it is we call "elegance". But I'm curious. Even if we can look at a bit of code, and say instinctively "That's elegant", or "That's messy", I wonder if any of us really understands what that means. Is there a precise definition for this "elegance" we keep referring to? If there is, what is it? Now, what I mean by a precise definition, is a series of statements which can be used to derive questions about a peice of code, or a program as a whole, and determine objectively, or as objectively as possible, whether that code is "elegant" or not. May I assert, that perhaps no such definition exists, and it's all just personal preference. In this case, I ask you a slightly different question: Is there a better word for "elegance", or a better set of attributes to use for judging code quality that is perhaps more objective than merely appealing to individual intuition and taste? Perhaps code quality is a matter of taste, and the answer to both of my questions is "no". But I can't help but feel that we could be doing better than just expressing wishy washy feelings about our code quality. For example, user interface design is something that to a broad range of people looks for all the world like a field of study that oughtta be 100% subjective matter of taste. But this is shockingly and brutally not the case, and there are in fact many objective measures that can be applied to a user interface to determine its quality. A series of tests could be written to give a definitive and repeatable score to user interface quality. (See GOMS, for instance). Now, okay. is Elegance simply "code quality" or is it something more? Is it something that can be measured? Or is it a matter of taste? Does our profession have room for taste? Maybe I'm asking the wrong questions altogether. Help me out here. Bonus Round If there is such a thing as elegance in code, and that concept is useful, do you think that justifies classifying the field of programming as an "Art" capital A, or merely a "craft". Or is it just an engineering field populated by a bunch of wishful thinking humans? Consider this question in the light of your thoughts about the elegance question. Please note that there is a distinction between code which is considered "art" in itself, and code that was written merely in the service of creating an artful program. When I ask this question, I ask if the code itself justifies calling programming an art. Bounty Note I liked the answers to this question so much, I think I'd like to make a photographic essay book from it. Released as a free PDF, and published on some kind of on demand printing service of course, such as "zazz" or "tiggle" or "printley" or something . I'd like some more answers, please!

  Read the article

• How to send web browser a loading page, then some time later a results page

  - by Kurt W. Leucht

  I've wasted at least a half day of my company's time searching the Internet for an answer and I'm getting wrapped around the axle here. I can't figure out the difference between all the different technology choices (long polling, ajax streaming, comet, XMPP, etc.) and I can't get a simple hello world example working on my PC. I am running Apache 2.2 and ActivePerl 5.10.0. JavaScript is completely acceptable for this solution. All I want to do is write a simple Perl CGI script that when accessed, it immediately returns some HTML that tells the user to wait or maybe sends an animated GIF. Then without any user intervention (no mouse clicks or anything) I want the CGI script to at some time later replace the wait message or the animated GIF with the actual results from their query. I know this is simple stuff and websites do it all the time using JavaScript, but I can't find a single working example that I can cut and paste onto my machine that will work in Perl. Here is my simple Hello World example that I've compiled from various Internet sources, but it doesn't seem to work. When I refresh this Perl CGI script in my web browser it prints nothing for 5 seconds, then it prints the PLEASE BE PATIENT web page, but not the results web page. So the Ajax XMLHttpRequest stuff obviously isn't working right. What am I doing wrong? #!C:\Perl\bin\perl.exe use CGI; use CGI::Carp qw/fatalsToBrowser warningsToBrowser/; sub Create_HTML { my $html = <<EOHTML; <html> <head> <meta http-equiv="pragma" content="no-cache" /> <meta http-equiv="expires" content="-1" /> <script type="text/javascript" > var xmlhttp=false; /*@cc_on @*/ /*@if (@_jscript_version >= 5) // JScript gives us Conditional compilation, we can cope with old IE versions. // and security blocked creation of the objects. try { xmlhttp = new ActiveXObject("Msxml2.XMLHTTP"); } catch (e) { try { xmlhttp = new ActiveXObject("Microsoft.XMLHTTP"); } catch (E) { xmlhttp = false; } } @end @*/ if (!xmlhttp && typeof XMLHttpRequest!='undefined') { try { xmlhttp = new XMLHttpRequest(); } catch (e) { xmlhttp=false; } } if (!xmlhttp && window.createRequest) { try { xmlhttp = window.createRequest(); } catch (e) { xmlhttp=false; } } </script> <title>Ajax Streaming Connection Demo</title> </head> <body> Some header text. <p> <div id="response">PLEASE BE PATIENT</div> <p> Some footer text. </body> </html> EOHTML return $html; } my $cgi = new CGI; print $cgi->header; print Create_HTML(); sleep(5); print "<script type=\"text/javascript\">\n"; print "\$('response').innerHTML = 'Here are your results!';\n"; print "</script>\n";

  Read the article

• Isn't it better to use a single try catch instead of tons of TryParsing and other error handling sometimes?

  - by Ryan Peschel

  I know people say it's bad to use exceptions for flow control and to only use exceptions for exceptional situations, but sometimes isn't it just cleaner and more elegant to wrap the entire block in a try-catch? For example, let's say I have a dialog window with a TextBox where the user can type input in to be parsed in a key-value sort of manner. This situation is not as contrived as you might think because I've inherited code that has to handle this exact situation (albeit not with farm animals). Consider this wall of code: class Animals { public int catA, catB; public float dogA, dogB; public int mouseA, mouseB, mouseC; public double cow; } class Program { static void Main(string[] args) { string input = "Sets all the farm animals CAT 3 5 DOG 21.3 5.23 MOUSE 1 0 1 COW 12.25"; string[] splitInput = input.Split(' '); string[] animals = { "CAT", "DOG", "MOUSE", "COW", "CHICKEN", "GOOSE", "HEN", "BUNNY" }; Animals animal = new Animals(); for (int i = 0; i < splitInput.Length; i++) { string token = splitInput[i]; if (animals.Contains(token)) { switch (token) { case "CAT": animal.catA = int.Parse(splitInput[i + 1]); animal.catB = int.Parse(splitInput[i + 2]); break; case "DOG": animal.dogA = float.Parse(splitInput[i + 1]); animal.dogB = float.Parse(splitInput[i + 2]); break; case "MOUSE": animal.mouseA = int.Parse(splitInput[i + 1]); animal.mouseB = int.Parse(splitInput[i + 2]); animal.mouseC = int.Parse(splitInput[i + 3]); break; case "COW": animal.cow = double.Parse(splitInput[i + 1]); break; } } } } } In actuality there are a lot more farm animals and more handling than that. A lot of things can go wrong though. The user could enter in the wrong number of parameters. The user can enter the input in an incorrect format. The user could specify numbers too large or too small for the data type to handle. All these different errors could be handled without exceptions through the use of TryParse, checking how many parameters the user tried to use for a specific animal, checking if the parameter is too large or too small for the data type (because TryParse just returns 0), but every one should result in the same thing: A MessageBox appearing telling the user that the inputted data is invalid and to fix it. My boss doesn't want different message boxes for different errors. So instead of doing all that, why not just wrap the block in a try-catch and in the catch statement just display that error message box and let the user try again? Maybe this isn't the best example but think of any other scenario where there would otherwise be tons of error handling that could be substituted for a single try-catch. Is that not the better solution?

  Read the article

• Qt - reloading widget contents

  - by bullettime

  I'm trying to modify the fridge magnets example by adding a button that will reload the widget where the draggable labels are drawn, reflecting any changes made to the text file it reads. I defined another class that would contain the button and the DragWidget object, so there would be an instance of this class instead of DragWidget in main(): class wrapWidget: public QWidget { public: wrapWidget(); }; wrapWidget::wrapWidget() { QGridLayout *gridlayout = new QGridLayout(); DragWidget *w = new DragWidget(); QPushButton *b = new QPushButton("refresh"); gridlayout ->addWidget(w,0,0); gridlayout ->addWidget(b,1,0); setLayout(gridlayout ); connect(b,SIGNAL(clicked()),w,SLOT(draw())); } The call to connect is where I'm trying to do the refresh thing. In the original fridge magnets example, all the label drawing code was inside the constructor of the DragWidget class. I moved that code to a public method that I named 'draw()', and called this method from the constructor instead. Here's DragWidget definition and implementation: #include <QWidget> QT_BEGIN_NAMESPACE class QDragEnterEvent; class QDropEvent; QT_END_NAMESPACE class DragWidget : public QWidget { public: DragWidget(QWidget *parent = 0); public slots: void draw(); protected: void dragEnterEvent(QDragEnterEvent *event); void dragMoveEvent(QDragMoveEvent *event); void dropEvent(QDropEvent *event); void mousePressEvent(QMouseEvent *event); void paintEvent(QPaintEvent *event); }; DragWidget::DragWidget(QWidget *parent) : QWidget(parent) { draw(); QPalette newPalette = palette(); newPalette.setColor(QPalette::Window, Qt::white); setPalette(newPalette); setMinimumSize(400, 100);//qMax(200, y)); setWindowTitle(tr("Fridge Magnets")); setAcceptDrops(true); } void DragWidget::draw(){ QFile dictionaryFile(":/dictionary/words.txt"); dictionaryFile.open(QFile::ReadOnly); QTextStream inputStream(&dictionaryFile); int x = 5; int y = 5; while (!inputStream.atEnd()) { QString word; inputStream >> word; if (!word.isEmpty()) { DragLabel *wordLabel = new DragLabel(word, this); wordLabel->move(x, y); wordLabel->show(); wordLabel->setAttribute(Qt::WA_DeleteOnClose); x += wordLabel->width() + 2; if (x >= 245) { x = 5; y += wordLabel->height() + 2; } } } } I thought that maybe calling draw() as a slot would be enough to reload the labels, but it didn't work. Putting the draw() call inside the widget's overriden paintEvent() instead of the constructor didn't work out as well, the program would end up in an infinite loop. What I did was obviously not the right way of doing it, so what should I be doing instead?

  Read the article

• Someone please help google create instuctions that windows users understand. googles "instructions"

  - by nathan

  Below are the only instructions i managed to find from google on how to install the android NDK, it is written as if we all run Linux and presumes we all understand what these obscure tools are. My comments and questions appear in Italics if somone who knows unix and windows would translate for google that would be great! Android NDK Installation Introduction: Please read docs/OVERVIEW.TXT to understand what the Android NDK is and is not. This file gives instructions on how to properly setup your NDK. I. Requirements: The Android NDK currently requires a Linux, OS X or Windows host operating system. Windows users will need to install Cygwin (http://www.cygwin.com) to use it. Note that running the NDK under MSys is not supported. You will need to have the Android SDK and its dependencies installed. The NDK cannot generate final application packages (.apk files), only the shared library files that can go into them. IMPORTANT: The Android NDK can only be used to target system images using the Cupcake (1.5) or later releases of the platform. This is due to subtle toolchain and ABI related changed that make it incompatible with 1.0 and 1.1 system images. The NDK requires GNU Make 3.81 or later being available on your development system. Earlier versions of GNU Make might work but have not been tested. You can check this by running 'make -v' from the command-line. The output should look like: GNU Make 3.81 Copyright (C) 2006 Free Software Foundation, Inc. ... On certain systems, GNU Make might be available through a different command like 'gmake' or 'gnumake'. For these systems, replace 'make' by the appropriate command when invoking the NDK build system as described in the documentation. Great some strange thing called gnu make.. if your not going to tell me what it does maybe you then at least you could give me a URL to it? The NDK also requires a Nawk or GNU Awk executable being available on your development system. Note that the original 'awk' program doesn't implement the 'match' and 'substr' functions used by the NDK build system. Ok another tool, with 1 of 2 possible names, but not the third... and again where should i download this?? On Windows, you will need to install a recent release of Cygwin to use the NDK. See http://www.cygwin.com for instructions. Woohoo a URL! download took about a day because these install instructions do not specify what parts to download. II. Preparing your installation prebuilt cross-toolchain binaries: After installing and unarchiving the NDK, you will need to run the following command from the root folder: build/host-setup.sh hello? windows dont run nothing but .exe .com or .dll, just tell me how you want me to run it.. This will test your setup and make sure the NDK can work properly. Nothing is said about where any of these things need to be installed to (what directory)

  Read the article

• C++ MySQL++ Delete query statement brain killer question

  - by shauny

  Hello all, I'm relatively new to the MySQL++ connector in C++, and have an really annoying issue with it already! I've managed to get stored procedures working, however i'm having issues with the delete statements. I've looked high and low and have found no documentation with examples. First I thought maybe the code needs to free the query/connection results after calling the stored procedure, but of course MySQL++ doesn't have a free_result method... or does it? Anyways, here's what I've got: #include <iostream> #include <stdio.h> #include <queue> #include <deque> #include <sys/stat.h> #include <mysql++/mysql++.h> #include <boost/thread/thread.hpp> #include "RepositoryQueue.h" using namespace boost; using namespace mysqlpp; class RepositoryChecker { private: bool _isRunning; Connection _con; public: RepositoryChecker() { try { this->_con = Connection(false); this->_con.set_option(new MultiStatementsOption(true)); this->_con.set_option(new ReconnectOption(true)); this->_con.connect("**", "***", "***", "***"); this->ChangeRunningState(true); } catch(const Exception& e) { this->ChangeRunningState(false); } } /** * Thread method which runs and creates the repositories */ void CheckRepositoryQueues() { //while(this->IsRunning()) //{ std::queue<RepositoryQueue> queues = this->GetQueue(); if(queues.size() > 0) { while(!queues.empty()) { RepositoryQueue &q = queues.front(); char cmd[256]; sprintf(cmd, "svnadmin create /home/svn/%s/%s/%s", q.GetPublicStatus().c_str(), q.GetUsername().c_str(), q.GetRepositoryName().c_str()); if(this->DeleteQueuedRepository(q.GetQueueId())) { printf("query deleted?\n"); } printf("Repository created!\n"); queues.pop(); } } boost::this_thread::sleep(boost::posix_time::milliseconds(500)); //} } protected: /** * Gets the latest queue of repositories from the database * and returns them inside a cool queue defined with the * RepositoryQueue class. */ std::queue<RepositoryQueue> GetQueue() { std::queue<RepositoryQueue> queues; Query query = this->_con.query("CALL sp_GetRepositoryQueue();"); StoreQueryResult result = query.store(); RepositoryQueue rQ; if(result.num_rows() > 0) { for(unsigned int i = 0;i < result.num_rows(); ++i) { rQ = RepositoryQueue((unsigned int)result[i][0], (unsigned int)result[i][1], (String)result[i][2], (String)result[i][3], (String)result[i][4], (bool)result[i][5]); queues.push(rQ); } } return queues; } /** * Allows the thread to be shut off. */ void ChangeRunningState(bool isRunning) { this->_isRunning = isRunning; } /** * Returns the running value of the active thread. */ bool IsRunning() { return this->_isRunning; } /** * Deletes the repository from the mysql queue table. This is * only called once it has been created. */ bool DeleteQueuedRepository(unsigned int id) { char cmd[256]; sprintf(cmd, "DELETE FROM RepositoryQueue WHERE Id = %d LIMIT 1;", id); Query query = this->_con.query(cmd); return (query.exec()); } }; I've removed all the other methods as they're not needed... Basically it's the DeleteQueuedRepository method which isn't working, the GetQueue works fine. PS: This is on a Linux OS (Ubuntu server) Many thanks, Shaun

  Read the article

• Linked list in C

  - by ScReYm0

  I am still new at lists in C and i got a big problem... First i wanna show you my code for inserting item to the list: void input_books_info(int number_of_books, BOOK *current) { int i; for(i = 0; i < number_of_books; i++) { while(current->next != NULL) current = current->next; current->next = (BOOK *)malloc(sizeof(BOOK)); printf_s("%d book catalog number: ", i + 1); scanf_s("%s", &current->next->catalog_number , 20); printf_s("%d book title: ", i + 1); scanf_s("%s", current->next->title ,80); printf_s("%d book author: ", i + 1); scanf_s("%s", current->next->author ,40); printf_s("%d book publisher: ", i+1); scanf_s("%s", current->next->publisher,80); printf_s("%d book price: ", i + 1); scanf_s("%f", &current->next->price, 5); printf_s("%d book year published: ", i + 1); scanf_s("%d", &current->next->year_published, 5); current->next->next = NULL; printf_s("\n\n"); } } And this is my main function: void main (void) { int number_of_books, t = 1; char book_catalog_number[STRMAX]; char book_title[STRMAX]; char book_author[STRMAX]; char reading_file[STRMAX]; char saving_file[STRMAX]; first = malloc(sizeof(BOOK)); first->next = NULL; /* printf_s("Enter file name: "); gets(saving_file); first->next = book_open(first, saving_file); */ while(t) { char m; printf_s("1. Input \n0. Exit \n\n"); printf_s("Choose operation: "); m = getch(); switch(m) { case '1': printf_s("\ninput number of books: "); scanf_s("%d", &number_of_books); input_books_info(number_of_books, first); printf_s("\n"); break; default: printf_s("\nNo entry found!\n\n\n\n\n"); break; } } } and last maybe here is the problem the printing function: void print_books_info(BOOK *current) { while(current->next != NULL && current != NULL) { printf_s("%s, ", current->next->catalog_number); printf_s("%s, ", current->author); printf_s("%s, ", current->next->title); printf_s("%s, ", current->next->author); printf_s("%s, ", current->next->publisher); printf_s("%.2f, ", current->next->price); printf_s("%d", current->next->year_published); printf_s("\n\n"); current = current->next; } } And my problem is that, when i run the app, program is moving good. But when I start the app, the program is storing only first input of data second and third are lost ... Can you help me to figure out it... ???

  Read the article

• Themes outside application.

  - by Marek

  Hi all I read http://forum.kohanaframework.org/comments.php?DiscussionID=5744&page=1#Item_0 and I want to use similar solution, but with db. In my site controller after(): $theme = $page->get_theme_name(); //Orange Kohana::set_module_path('themes', Kohana::get_module_path('themes').'/'.$theme); $this->template = View::factory('layout') I checked with firebug: fire::log(Kohana::get_module_path('themes')); // D:\tools\xampp\htdocs\kohana\themes/Orange I am sure that path exists. I have directly in 'Orange' folder 'views' folder with layout.php file. But I am getting: The requested view layout could not be found Extended Kohana_Core is just: public static function get_module_path($module_key) { return self::$_modules[$module_key]; } public static function set_module_path($module_key, $path) { self::$_modules[$module_key] = $path; } Could anybody help me with solving that issue? Maybe it is a .htaccess problem: # Turn on URL rewriting RewriteEngine On # Put your installation directory here: # If your URL is www.example.com/kohana/, use /kohana/ # If your URL is www.example.com/, use / RewriteBase /kohana/ # Protect application and system files from being viewed RewriteCond $1 ^(application|system|modules) # Rewrite to index.php/access_denied/URL RewriteRule ^(.*)$ / [PT,L] RewriteRule ^(media) - [PT,L] RewriteRule ^(themes) - [PT,L] # Allow these directories and files to be displayed directly: # - index.php (DO NOT FORGET THIS!) # - robots.txt # - favicon.ico # - Any file inside of the images/, js/, or css/ directories RewriteCond $1 ^(index\.php|robots\.txt|favicon\.ico|static) # No rewriting RewriteRule ^(.*)$ - [PT,L] # Rewrite all other URLs to index.php/URL RewriteRule ^(.*)$ index.php/$1 [PT,L] Could somebody help? What I am doing wrong? Regards [EDIT] My controller code: class Controller_Site extends Controller_Fly { public static $meta_names = array('keywords', 'descriptions', 'author'); public function action_main() { $this->m('page')->get_main_page(); } public function action_page($page_title) { $this->m('page')->get_by_link($page_title); } public function after() { $page = $this->m('page'); $metas = ''; foreach(self::$meta_names as $meta) { if (! empty($page->$meta)) { $metas .= html::meta($page->$meta, $meta).PHP_EOL; } } $theme = $page->get_theme_name(); Kohana::set_module_path('themes', Kohana::get_module_path('themes').'/'.$theme); $menus = $page->get_menus(); $this->template = View::factory('layout') ->set('theme', $theme) ->set('metas', $metas) ->set('menus', $menus['content']) ->set('sections', $page->get_sections()) ->set_global('page', $page); if ($page->header_on) { $settings = $this->m('setting'); $this->template->header = View::factory('/header') ->set('title', $settings->title) ->set('subtitle', $settings->subtitle) ->set('menus', $menus['header']); } if ($page->sidebar_on) { $this->template->sidebar = View::factory('sidebar', array('menus' => $menus['sidebar'])); } if ($page->footer_on) { $this->template->footer = View::factory('footer'); } parent::after(); } } and parent controller: abstract class Controller_Fly extends Controller_Template { protected function m($model_name, $id = NULL) { if (! isset($this->$model_name)) { $this->$model_name = ORM::factory($model_name, $id); } return $this->$model_name; } protected function mf($model_name, $id = NULL) { return ORM::factory($model_name, $id); } }

  Read the article

• What is the best way to test using grails using IDEA?

  - by egervari

  I am seriously having a very non-pleasant time testing using Grails. I will describe my experience, and I'd like to know if there's a better way. The first problem I have with testing is that Grails doesn't give immediate feedback to the developer when .save() fails inside of an integration test. So let's say you have a domain class with 12 fields, and 1 of them is violating a constraint and you don't know it when you create the instance... it just doesn't save. Naturally, the test code afterward is going to fail. This is most troublesome because the thingy under test is probably fine... and the real risk and pain is the setup code for the test itself. So, I've tried to develop the habit of using .save(failOnError: true) to avoid this problem, but that's not something that can be easily enforced by everyone working on the project... and it's kind of bloaty. It'd be nice to turn this on for code that is running as part of a unit test automatically. Integration Tests run slow. I cannot understand how 1 integration test that saves 1 object takes 15-20 seconds to run. With some careful test planning, I've been able to get 1000 tests talking to an actual database and doing dbunit dumps after every test to happen in about the same time! This is dumb. It is hard to run all the unit tests and not integration tests in IDEA. Integration tests are a massive pain. Idea actually shows a GREEN BAR when integration tests fail. The output given by grails indicates that something failed, but it doesn't say what it was. It says to look in the test reports... which forces the developer to launch up their file system to hunt the stupid html file down. What a pain. Then once you got the html file and click to the failing test, it'll tell you a line number. Since these reports are not in the IDE, you can't just click the stack trace to go to that line of code... you gotta go back and find it yourself. ARGGH!@!@! Maybe people put up with this, but I refuse. Testing should not be this painful. It should be fast and painless, or people won't do it. Please help. What is the solution? Rails instead of Grails? Something else entirely? I love the Grails framework, but they never demo their testing for a reason. They have a snazzy framework, but the testing is painful. After having used Scala for the last 1.5 months, and being totally spoiled by ScalaTest... I can't go back to this.

  Read the article

• Is this way the best solution to read and save images from Rss Feeds?

  - by Keyne

  Hi, I've build a "RSS Feed Reader" module to my application, and for every post with images in the content, I get the first that matches a specific size and then I save for future use as reference to the posts. When processing, everything works properly except when more then 10 images are saved at the same time (This value is variable). I got an 404 error after a while saving the images. Some images are saved, but not all of them. If I run the app in my local server, everything work as expected (using set_timeout(0) to avoid timeout errors). Currently my application is hosted at dreamhost and I'm using Zend Framework. I'm not sure if the problem is specif for Zend Framework applications, so I didn't put any tags about. I've had this problem another time with other projects hosted at dreamhost. They seems to limitate memory for operations like that. My question is: There is a better way to save images then this (maybe in background? a limited amount per operation?): require_once(APPLICATION_PATH . '/../library/simplehtmldom/simple_html_dom.php'); $TableFeeds = new Model_DbTable_Feeds(); $Feeds = $TableFeeds->fetchAll(); foreach($Feeds as $Feed) { $entries = Zend_Feed_Reader::import($Feed->link); $lastEntry = $this->getLastEntry($Feed->id); if($lastEntry) { $lastDate = new Zend_Date($lastEntry->created_at, Zend_Date::ISO_8601); } foreach ($entries as $entry) { if($lastDate) { if(strtotime($lastDate->get('y-M-d H:m:s')) >= strtotime($entry->getDateCreated()->get('y-M-d H:m:s'))) { break; } } $Category = new Model_DbTable_Categorias(); $availableCategories = $Category->getList('slug'); $categoria_id = false; foreach ($categories as $cat) { if(!empty($cat) && !$categoria_id) { $slug = Zf_Convert::slugfy($cat); if($availableCategories[$Feed->categoria_id] == $slug) { $categoria_id = $Feed->categoria_id; break; } if(in_array($slug,$availableCategories)) { $categoria_id = array_search($slug,$availableCategories); break; } } } if(!$categoria_id) { $categoria_id = $Feed->categoria_id; } // Cadastra a entrada $data = array( 'categoria_id' => $categoria_id, 'feed_id' => $Feed->id, 'titulo' => $entry->getTitle(), 'slug' => Zf_Convert::slugfy($entry->getTitle()), 'created_at' => $entry->getDateCreated()->get(Zend_Date::ISO_8601), 'link' => $entry->getLink(), 'html' => $entry->getContent(), 'tags' => $tags ); $entry_id = $this->insert($data); if($categoria_id == 2) { set_time_limit(0); $post_dom = str_get_dom($entry->getContent()); $img_tags = $post_dom->find('img'); $images = array(); foreach($img_tags as $image) { $images[] = $image->src; } if(count($images)) { $i = 0; $saved = false; while($images[$i] && !$saved) { $src = $images[$i]; $imagem = Zf_Image::create($src); $size = $imagem->getCurrentDimensions(); if($size['width'] >= 150 && $size['height'] >= 200) { $imagem->adaptiveResize(200,200); $imagem->save(PUBLIC_PATH . '/img/feeds/manchetes/' . $entry_id . '.jpg'); $saved = true; $this->update(array('imagemChamada' => 1),'id =' . $entry_id); } $i++; } } } } } }

  Read the article

• Covariance and Contravariance in C#

  - by edalorzo

  I will start by saying that I am Java developer learning to program in C#. As such I do comparisons of what I know with what I am learning. I have been playing with C# generics for a few hours now, and I have been able to reproduce the same things I know in Java in C#, with the exception of a couple of examples using covariance and contravariance. The book I am reading is not very good in the subject. I will certainly seek more info on the web, but while I do that, perhaps you can help me find a C# implementation for the following Java code. An example is worth a thousand words, and I was hoping that by looking a good code sample I will be able to assimilate this more rapidly. Covariance In Java I can do something like this: public static double sum(List<? extends Number> numbers) { double summation = 0.0; for(Number number : numbers){ summation += number.doubleValue(); } return summation; } I can use this code as follows: List<Integer> myInts = asList(1,2,3,4,5); List<Double> myDoubles = asList(3.14, 5.5, 78.9); List<Long> myLongs = asList(1L, 2L, 3L); double result = 0.0; result = sum(myInts); result = sum(myDoubles) result = sum(myLongs); Now I did discover that C# supports covariance/contravariance only on interfaces and as long as they have been explicitly declared to do so (out). I think I was not able to reproduce this case, because I could not find a common ancestor of all numbers, but I believe that I could have used IEnumerable to implement such thing if a common ancestor exists. Since IEnumerable is a covariant type. Right? Any thoughts on how to implement the list above? Just point me into the right direction. Is there any common ancestor of all numeric types? Contravariance The contravariance example I tried was the following. In Java I can do this to copy one list into another. public static void copy(List<? extends Number> source, List<? super Number> destiny){ for(Number number : source) { destiny.add(number); } } Then I could use it with contravariant types as follows: List<Object> anything = new ArrayList<Object>(); List<Integer> myInts = asList(1,2,3,4,5); copy(myInts, anything); My basic problem, trying to implement this in C# is that I could not find an interface that was both covariant and contravariant at the same time, as it is case of List in my example above. Maybe it can be done with two different interface in C#. Any thoughts on how to implement this? Thank you very much to everyone for any answers you can contribute. I am pretty sure I will learn a lot from any example you can provide.

  Read the article

• Hard crash when drawing content for CALayer using quartz

  - by Lukasz

  I am trying to figure out why iOS crash my application in the harsh way (no crash logs, immediate shudown with black screen of death with spinner shown for a while). It happens when I render content for CALayer using Quartz. I suspected the memory issue (happens only when testing on the device), but memory logs, as well as instruments allocation logs looks quite OK. Let me past in the fatal function: - (void)renderTiles{ if (rendering) { //NSLog(@"====== RENDERING TILES SKIP ======="); return; } rendering = YES; CGRect b = tileLayer.bounds; CGSize s = b.size; CGFloat imageScale = [[UIScreen mainScreen] scale]; s.height *= imageScale; s.width *= imageScale; dispatch_async(queue, ^{ NSLog(@""); NSLog(@"====== RENDERING TILES START ======="); NSLog(@"1. Before creating context"); report_memory(); CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); NSLog(@"2. After creating color space"); report_memory(); NSLog(@"3. About to create context with size: %@", NSStringFromCGSize(s)); CGContextRef ctx = CGBitmapContextCreate(NULL, s.width, s.height, 8, 0, colorSpace, kCGImageAlphaPremultipliedLast); NSLog(@"4. After creating context"); report_memory(); CGAffineTransform flipTransform = CGAffineTransformMake(1.0, 0.0, 0.0, -1.0, 0.0, s.height); CGContextConcatCTM(ctx, flipTransform); CGRect tileRect = CGRectMake(0, 0, tileImageScaledSize.width, tileImageScaledSize.height); CGContextDrawTiledImage(ctx, tileRect, tileCGImageScaled); NSLog(@"5. Before creating cgimage from context"); report_memory(); CGImageRef cgImage = CGBitmapContextCreateImage(ctx); NSLog(@"6. After creating cgimage from context"); report_memory(); dispatch_sync(dispatch_get_main_queue(), ^{ tileLayer.contents = (id)cgImage; }); NSLog(@"7. After asgning tile layer contents = cgimage"); report_memory(); CGColorSpaceRelease(colorSpace); CGContextRelease(ctx); CGImageRelease(cgImage); NSLog(@"8. After releasing image and context context"); report_memory(); NSLog(@"====== RENDERING TILES END ======="); NSLog(@""); rendering = NO; }); } Here are the logs: ====== RENDERING TILES START ======= 1. Before creating context Memory in use (in bytes): 28340224 / 519442432 (5.5%) 2. After creating color space Memory in use (in bytes): 28340224 / 519442432 (5.5%) 3. About to create context with size: {6324, 5208} 4. After creating context Memory in use (in bytes): 28344320 / 651268096 (4.4%) 5. Before creating cgimage from context Memory in use (in bytes): 153649152 / 651333632 (23.6%) 6. After creating cgimage from context Memory in use (in bytes): 153649152 / 783159296 (19.6%) 7. After asgning tile layer contents = cgimage Memory in use (in bytes): 153653248 / 783253504 (19.6%) 8. After releasing image and context context Memory in use (in bytes): 21688320 / 651288576 (3.3%) ====== RENDERING TILES END ======= Application crashes in random places. Sometimes when reaching en of the function and sometime in random step. Which direction should I look for a solution? Is is possible that GDC is causing the problem? Or maybe the context size or some Core Animation underlying references?

  Read the article

• Background custom button animation using WPF

  - by ajtp

  Hi, I am using Resources dictionaries to customize my controls and apply them as themes to my WPF application so I have implemented one for the button control. A code snippet for my custom Button.xaml is (its namespace is MyWPFApp.Themes): <ResourceDictionary ...> ... <LinearGradientBrush x:Key="NormalBackground" EndPoint="0,1" StartPoint="0,0"> <GradientStop Color="sc#1.000000, 0.250141, 0.333404, 0.884413" Offset="0"/> <GradientStop Color="#ccffffff" Offset="1"/> </LinearGradientBrush> <LinearGradientBrush x:Key="OverBackground" EndPoint="0,1" StartPoint="0,0"> <GradientStop Color="#da5e69" Offset="0"/> <GradientStop Color="#d12e27" Offset="1"/> </LinearGradientBrush> <LinearGradientBrush x:Key="ClickBackground" EndPoint="0,1" StartPoint="0,0"> <GradientStop Color="#d22828" Offset="1"/> <GradientStop Color="#b00000" Offset="0"/> </LinearGradientBrush> ... <Style TargetType="{x:Type Button}"> ... <Setter Property="Background" Value="{StaticResource NormalBackground}"/> ... </Style> </ResourceDictionary> and I apply it by doing the following from my main Application.xaml: <Application ...> <Application.Resources> <ResourceDictionary> <ResourceDictionary.MergedDictionaries> <ResourceDictionary Source="Themes/Button.xaml"/> </ResourceDictionary.MergedDictionaries> </ResourceDictionary> </Application.Resources> </Application> What I try to do is to change background color, for example, from White to Lime for 6 seconds by doing this from one of my pages, MyPage1.xaml, using StoryBoard: <Page x:Class="MyWPFApp.Pages.MyPage1" ...> <Page.Resources> ... <Storyboard x:Key="sbBtnResetHC" Storyboard.TargetName="BtnResetHC" Storyboard.TargetProperty="(Background). (SolidColorBrush.Color)"> <ColorAnimation From="Pink" To="Green" By="Blue" Duration="0:0:6" RepeatBehavior="3x" AutoReverse="True" /> </Storyboard> ... </Page.Resources> ... <Button x:Name="BtnResetHC" Click="BtnResetHC_Click" Width="90" Visibility="Collapsed" /> ... </Page> and from code behind MyPage1.xaml.cs I start animation by doing this: Storyboard sb = (Storyboard)FindResource("sbBtnResetHC"); sb.Begin(); when the button is visible, but it doesn't work for me. Any ideas what's wrong? Maybe another possibility, as I want the animation starts on button visible is to do a trigger for the button over Visibility property, Is it a better solution? Thanks a lot!

  Read the article

• translating play in HTML to python

  - by aharon

  So, I'd like to represent one of Shakespeare's plays, Hamlet, into the following objects (maybe this isn't the best representation, if so please tell me): class Play(): acts = [] ... def add_act(self, act): acts.append(act) class Act(): scenes = [] ... def add_scene(self, scene): scenes.append(scene) class Scene(): elems = [] def __init__(self, title, setting=""): ... def add_elem(self, elem): elems.append(elem) ... class StageDirection(): # elem def __init__(self, text): ... class Line(): # elem def __init__(self, id, text, character = None): ... # A None character represents a continuation from the previous line # id could be, for example, 1.1.1 There are other methods, of course, for printing and such in each of the classes. The question is, how do I get a structure based on these classes (or something like them) from HTML 4 code that looks like this: <H3>ACT I</h3> <h3>SCENE I. Elsinore. A platform before the castle.</h3> <p><blockquote> <i>FRANCISCO at his post. Enter to him BERNARDO</i> </blockquote> <A NAME=speech1><b>BERNARDO</b></a> <blockquote> <A NAME=1.1.1>Who's there?</A><br> </blockquote> <A NAME=speech2><b>FRANCISCO</b></a> <blockquote> <A NAME=1.1.2>Nay, answer me: stand, and unfold yourself.</A><br> </blockquote> <A NAME=speech3><b>BERNARDO</b></a> <blockquote> <A NAME=1.1.3>Long live the king!</A><br> </blockquote> <A NAME=speech4><b>FRANCISCO</b></a> <blockquote> <A NAME=1.1.4>Bernardo?</A><br> </blockquote> <A NAME=speech5><b>BERNARDO</b></a> <blockquote> <A NAME=1.1.5>He.</A><br> </blockquote> <!-- for more, see the source of shakespeare.mit.edu/hamlet/full.html --> translating that into something like this: play = Play() actI = Act() sceneI = Scene("Scene I", "Elsinore. A platform before the castle.") sceneI.add_elem(StageDirection("Francisco at his post. Enter to him Bernardo.")) sceneI.add_elem(Line("Bernardo", "Who's there?")) ... Of course, I don't expect all the code—but what libraries and, when there aren't libraries, logic should I use? Thanks. (This is for a future opensource project and me learning Python for fun—not homework.)

  Read the article

• Design Question - how do you break the dependency between classes using an interface?

  - by Seth Spearman

  Hello, I apologize in advance but this will be a long question. I'm stuck. I am trying to learn unit testing, C#, and design patterns - all at once. (Maybe that's my problem.) As such I am reading the Art of Unit Testing (Osherove), and Clean Code (Martin), and Head First Design Patterns (O'Reilly). I am just now beginning to understand delegates and events (which you would see if you were to troll my SO questions of recent). I still don't quite get lambdas. To contextualize all of this I have given myself a learning project I am calling goAlarms. I have an Alarm class with members you'd expect (NextAlarmTime, Name, AlarmGroup, Event Trigger etc.) I wanted the "Timer" of the alarm to be extensible so I created an IAlarmScheduler interface as follows... public interface AlarmScheduler { Dictionary<string,Alarm> AlarmList { get; } void Startup(); void Shutdown(); void AddTrigger(string triggerName, string groupName, Alarm alarm); void RemoveTrigger(string triggerName); void PauseTrigger(string triggerName); void ResumeTrigger(string triggerName); void PauseTriggerGroup(string groupName); void ResumeTriggerGroup(string groupName); void SetSnoozeTrigger(string triggerName, int duration); void SetNextOccurrence (string triggerName, DateTime nextOccurrence); } This IAlarmScheduler interface define a component that will RAISE an alarm (Trigger) which will bubble up to my Alarm class and raise the Trigger Event of the alarm itself. It is essentially the "Timer" component. I have found that the Quartz.net component is perfectly suited for this so I have created a QuartzAlarmScheduler class which implements IAlarmScheduler. All that is fine. My problem is that the Alarm class is abstract and I want to create a lot of different KINDS of alarm. For example, I already have a Heartbeat alarm (triggered every (int) interval of minutes), AppointmentAlarm (triggered on set date and time), Daily Alarm (triggered every day at X) and perhaps others. And Quartz.NET is perfectly suited to handle this. My problem is a design problem. I want to be able to instantiate an alarm of any kind without my Alarm class (or any derived classes) knowing anything about Quartz. The problem is that Quartz has awesome factories that return just the right setup for the Triggers that will be needed by my Alarm classes. So, for example, I can get a Quartz trigger by using TriggerUtils.MakeMinutelyTrigger to create a trigger for the heartbeat alarm described above. Or TriggerUtils.MakeDailyTrigger for the daily alarm. I guess I could sum it up this way. Indirectly or directly I want my alarm classes to be able to consume the TriggerUtils.Make* classes without knowing anything about them. I know that is a contradiction, but that is why I am asking the question. I thought about putting a delegate field into the alarm which would be assigned one of these Make method but by doing that I am creating a hard dependency between alarm and Quartz which I want to avoid for both unit testing purposes and design purposes. I thought of using a switch for the type in QuartzAlarmScheduler per here but I know it is bad design and I am trying to learn good design. If I may editorialize a bit. I've decided that coding (predefined) classes is easy. Design is HARD...in fact, really hard and I am really fighting feeling stupid right now. I guess I want to know if you really smart people took a while to really understand and master this stuff or should I feel stupid (as I do) because I haven't grasped it better in the couple of weeks/months I have been studying. You guys are awesome and thanks in advance for your answers. Seth

  Read the article

• fonts mac vs pc

  - by Kieran

  Hi all hope your having a good day/evening. Simple question, but maybe not so simple to answer. I have an unordered list, which i am using as a menu. The list items are floated right and sized due to an anchor tag inside them with a roll over. The last element is given a specific size to suck up any extra space. See the code snippits bellow. css ul.mainNav { width: 970px; display:block; background:black; clear:both; overflow:hidden;} ul.mainNav li { float: left; height:29px;} ul.mainNav li a { display: block; padding:7px 19px; color:#ffffff; background-color:#000; font-weight:bold; text-decoration:none; font-size:13px; } ul.mainNav li a:hover, ul.mainNav li a.selected { background-color:#ffff00; color:#000; } ul.mainNav li a.last{ text-align:center; padding: 7px 19px; width:58px;} html <ul class="mainNav" id="mainNav"> <li><a href="/Default.aspx">home</a></li> <li><a href="/About/">about</a></li> <li><a href="/News/">news</a></li> <li><a href="/Enter/Registration.aspx">enter SOYA 2010</a></li> <li><a href="/Categories/Film.aspx">categories</a></li> <li><a href="/Mentors/janChapman.aspx">mentors</a></li> <li><a href="/PastWinners/">past winners</a></li> <li><a href="/Awards/">awards nights</a></li> <li><a href="/Support/" class="last">contact</a></li> </ul> It is containted in a <div style="margin:0 auto;">...</div> to center on the menu on screen Now my problem is: On PC; firefox/ Safari /IE /Chrome are all displaying correctly. Take the same code to a Mac; Safari/ firefox are displaying the menu to be too short and the only thing i can point to is that the fonts may be smaller in widths. The width is currently set to 970px. My question is: How can i get it to display at the same widths without specifying exact widths for each list item? Any help would be appreciated. If my structure is wrong or it is just a mac thing that i will never solve(hope not). Cheers, KJ

  Read the article

• jquery with ASP.NET MVC - calling ajax enabled web service

  - by dcp

  This is a bit of a continuation of a previous question. Now I'm trying to make a call to an AJAX enabled web service which I have defined within the ASP.NET MVC application (i.e. the MovieService.svc). But the service is never being called in my getMovies javascript function. This same technique of calling the AJAX web service works ok if I try it in a non ASP.NET MVC application, so it makes me wonder if maybe the ASP MVC routes are interfering with things somehow when it tries to make the AJAX web service call. Do you have any idea why my web service isn't getting called? Code below. <script src="<%= ResolveClientUrl("~/scripts/jquery-1.4.2.min.js") %>" type="text/javascript"></script> <script src="<%= ResolveClientUrl("~/scripts/grid.locale-en.js") %>" type="text/javascript"></script> <script src="<%= ResolveClientUrl("~/scripts/jquery-ui-1.8.1.custom.min.js") %>" type="text/javascript"></script> <script src="<%= ResolveClientUrl("~/scripts/jquery.jqGrid.min.js") %>" type="text/javascript"></script> <script type="text/javascript"> var lastsel2; function successFunction(jsondata) { debugger var thegrid = jQuery("#editgrid"); for (var i = 0; i < jsondata.d.length; i++) { thegrid.addRowData(i + 1, jsondata.d[i]); } } function getMovies() { debugger // ***** the MovieService#GetMovies method never gets called $.ajax({ url: 'MovieService.svc/GetMovies', data: "{}", // For empty input data use "{}", dataType: "json", type: "GET", contentType: "application/json; charset=utf-8", success: successFunction }); } jQuery(document).ready(function() { jQuery("#editgrid").jqGrid({ datatype: getMovies, colNames: ['id', 'Movie Name', 'Directed By', 'Release Date', 'IMDB Rating', 'Plot', 'ImageURL'], colModel: [ { name: 'id', index: 'Id', width: 55, sortable: false, hidden: true, editable: false, editoptions: { readonly: true, size: 10} }, { name: 'Movie Name', index: 'Name', width: 250, editable: true, editoptions: { size: 10} }, { name: 'Directed By', index: 'Director', width: 250, align: 'right', editable: true, editoptions: { size: 10} }, { name: 'Release Date', index: 'ReleaseDate', width: 100, align: 'right', editable: true, editoptions: { size: 10} }, { name: 'IMDB Rating', index: 'IMDBUserRating', width: 100, align: 'right', editable: true, editoptions: { size: 10} }, { name: 'Plot', index: 'Plot', width: 150, hidden: false, editable: true, editoptions: { size: 30} }, { name: 'ImageURL', index: 'ImageURL', width: 55, hidden: true, editable: false, editoptions: { readonly: true, size: 10} } ], pager: jQuery('#pager'), rowNum: 5, rowList: [5, 10, 20], sortname: 'id', sortorder: "desc", height: '100%', width: '100%', viewrecords: true, imgpath: '/Content/jqGridCss/redmond/images', caption: 'Movies from 2008', editurl: '/Home/EditMovieData/', caption: 'Movie List' }); $("#bedata").click(function() { var gr = jQuery("#editgrid").jqGrid('getGridParam', 'selrow'); if (gr != null) jQuery("#editgrid").jqGrid('editGridRow', gr, { height: 280, reloadAfterSubmit: false }); else alert("Hey dork, please select a row"); }); }); </script> <h2> <%= Html.Encode(ViewData["Message"]) %></h2> <p> To learn more about ASP.NET MVC visit <a href="http://asp.net/mvc" title="ASP.NET MVC Website"> http://asp.net/mvc</a>. </p> <table id="editgrid"> </table> <div id="pager" style="text-align: center;"> </div> <input type="button" id="bedata" value="Edit Selected" /> Here's my RegisterRoutes code: public static void RegisterRoutes(RouteCollection routes) { routes.IgnoreRoute("{resource}.axd/{*pathInfo}"); routes.IgnoreRoute("*MovieService.svc*"); routes.MapRoute( "Default", // Route name "{controller}/{action}/{id}", // URL with parameters new { controller = "Home", action = "Index", id = "" } // Parameter defaults ); } Here's what my MovieService class looks like: namespace jQueryMVC { [ServiceContract(Namespace = "")] [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)] public class MovieService { // Add [WebGet] attribute to use HTTP GET [OperationContract] [WebGet(ResponseFormat = WebMessageFormat.Json)] public IList<Movie> GetMovies() { return Persistence.GetMovies(); } } }

  Read the article

• Java Refuses to Start - Could not reserve enough space for object heap

  - by Randyaa

  Background We have a pool of aproximately 20 linux blades. Some are running Suse, some are running Redhat. ALL share NAS space which contains the following 3 folders: /NAS/app/java - a symlink that points to an installation of a Java JDK. Currently version 1.5.0_10 /NAS/app/lib - a symlink that points to a version of our application. /NAS/data - directory where our output is written All our machines have 2 processors (hyperthreaded) with 4gb of physical memory and 4gb of swap space. We limit the number of 'jobs' each machine can process at a given time to 6 (this number likely needs to change, but that does not enter into the current problem so please ignore it for the time being). Some of our jobs set a Max Heap size of 512mb, some others reserve a Max Heap size of 2048mb. Again, we realize we could go over our available memory if 6 jobs started on the same machine with the heap size set to 2048, but to our knowledge this has not yet occurred. The Problem Once and a while a Job will fail immediately with the following message: Error occurred during initialization of VM Could not reserve enough space for object heap Could not create the Java virtual machine. We used to chalk this up to too many jobs running at the same time on the same machine. The problem happened infrequently enough (MAYBE once a month) that we'd just restart it and everything would be fine. The problem has recently gotten much worse. All of our jobs which request a max heap size of 2048m fail immediately almost every time and need to get restarted several times before completing. We've gone out to individual machines and tried executing them manually with the same result. Debugging It turns out that the problem only exists for our SuSE boxes. The reason it has been happening more frequently is becuase we've been adding more machines, and the new ones are SuSE. 'cat /proc/version' on the SuSE boxes give us: Linux version 2.6.5-7.244-bigsmp (geeko@buildhost) (gcc version 3.3.3 (SuSE Linux)) #1 SMP Mon Dec 12 18:32:25 UTC 2005 'cat /proc/version' on the RedHat boxes give us: Linux version 2.4.21-32.0.1.ELsmp ([email protected]) (gcc version 3.2.3 20030502 (Red Hat Linux 3.2.3-52)) #1 SMP Tue May 17 17:52:23 EDT 2005 'uname -a' gives us the following on BOTH types of machines: UTC 2005 i686 i686 i386 GNU/Linux No jobs are running on the machine, and no other processes are utilizing much memory. All of the processes currently running might be using 100mb total. 'top' currently shows the following: Mem: 4146528k total, 3536360k used, 610168k free, 132136k buffers Swap: 4194288k total, 0k used, 4194288k free, 3283908k cached 'vmstat' currently shows the following: procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 0 0 0 610292 132136 3283908 0 0 0 2 26 15 0 0 100 0 If we kick off a job with the following command line (Max Heap of 1850mb) it starts fine: java/bin/java -Xmx1850M -cp helloworld.jar HelloWorld Hello World If we bump up the max heap size to 1875mb it fails: java/bin/java -Xmx1875M -cp helloworld.jar HelloWorld Error occurred during initialization of VM Could not reserve enough space for object heap Could not create the Java virtual machine. It's quite clear that the memory currently being used is for Buffering/Caching and that's why so little is being displayed as 'free'. What isn't clear is why there is a magical 1850mb line where anything higher means Java can't start. Any explanations would be greatly appreciated.

  Read the article

• When should I use indexed arrays of OpenGL vertices?

  - by Tartley

  I'm trying to get a clear idea of when I should be using indexed arrays of OpenGL vertices, drawn with gl[Multi]DrawElements and the like, versus when I should simply use contiguous arrays of vertices, drawn with gl[Multi]DrawArrays. (Update: The consensus in the replies I got is that one should always be using indexed vertices.) I have gone back and forth on this issue several times, so I'm going to outline my current understanding, in the hopes someone can either tell me I'm now finally more or less correct, or else point out where my remaining misunderstandings are. Specifically, I have three conclusions, in bold. Please correct them if they are wrong. One simple case is if my geometry consists of meshes to form curved surfaces. In this case, the vertices in the middle of the mesh will have identical attributes (position, normal, color, texture coord, etc) for every triangle which uses the vertex. This leads me to conclude that: 1. For geometry with few seams, indexed arrays are a big win. Follow rule 1 always, except: For geometry that is very 'blocky', in which every edge represents a seam, the benefit of indexed arrays is less obvious. To take a simple cube as an example, although each vertex is used in three different faces, we can't share vertices between them, because for a single vertex, the surface normals (and possible other things, like color and texture co-ord) will differ on each face. Hence we need to explicitly introduce redundant vertex positions into our array, so that the same position can be used several times with different normals, etc. This means that indexed arrays are of less use. e.g. When rendering a single face of a cube: 0 1 o---o |\ | | \ | | \| o---o 3 2 (this can be considered in isolation, because the seams between this face and all adjacent faces mean than none of these vertices can be shared between faces) if rendering using GL_TRIANGLE_FAN (or _STRIP), then each face of the cube can be rendered thus: verts = [v0, v1, v2, v3] colors = [c0, c0, c0, c0] normal = [n0, n0, n0, n0] Adding indices does not allow us to simplify this. From this I conclude that: 2. When rendering geometry which is all seams or mostly seams, when using GL_TRIANGLE_STRIP or _FAN, then I should never use indexed arrays, and should instead always use gl[Multi]DrawArrays. (Update: Replies indicate that this conclusion is wrong. Even though indices don't allow us to reduce the size of the arrays here, they should still be used because of other performance benefits, as discussed in the comments) The only exception to rule 2 is: When using GL_TRIANGLES (instead of strips or fans), then half of the vertices can still be re-used twice, with identical normals and colors, etc, because each cube face is rendered as two separate triangles. Again, for the same single cube face: 0 1 o---o |\ | | \ | | \| o---o 3 2 Without indices, using GL_TRIANGLES, the arrays would be something like: verts = [v0, v1, v2, v2, v3, v0] normals = [n0, n0, n0, n0, n0, n0] colors = [c0, c0, c0, c0, c0, c0] Since a vertex and a normal are often 3 floats each, and a color is often 3 bytes, that gives, for each cube face, about: verts = 6 * 3 floats = 18 floats normals = 6 * 3 floats = 18 floats colors = 6 * 3 bytes = 18 bytes = 36 floats and 18 bytes per cube face. (I understand the number of bytes might change if different types are used, the exact figures are just for illustration.) With indices, we can simplify this a little, giving: verts = [v0, v1, v2, v3] (4 * 3 = 12 floats) normals = [n0, n0, n0, n0] (4 * 3 = 12 floats) colors = [c0, c0, c0, c0] (4 * 3 = 12 bytes) indices = [0, 1, 2, 2, 3, 0] (6 shorts) = 24 floats + 12 bytes, and maybe 6 shorts, per cube face. See how in the latter case, vertices 0 and 2 are used twice, but only represented once in each of the verts, normals and colors arrays. This sounds like a small win for using indices, even in the extreme case of every single geometry edge being a seam. This leads me to conclude that: 3. When using GL_TRIANGLES, one should always use indexed arrays, even for geometry which is all seams. Please correct my conclusions in bold if they are wrong.

  Read the article

• Looking for best practise for writing a serial device communication app

  - by cdotlister

  I am pretty new to serial comms, but would like advise on how to best achieve a robust application which speak to and listens to a serial device. I have managed to make use of System.IO.SerialPort, and successfully connected to, sent data to and recieved from my device. The way things work is this. My application connects to the Com Port and opens the port.... I then connect my device to the com port, and it detects a connection to the PC, so sends a bit of text. it's really just copyright info, as well as the version of the firmware. I don't do anything with that, except display it in my 'activity' window. The device then waits. I can then query information, but sending a command such as 'QUERY PARAMETER1'. It then replies with something like: 'QUERY PARAMETER1\r\n\r\n76767\r\n\r\n' I then process that. I can then update it by sending 'SET PARAMETER1 12345', and it will reply with 'QUERY PARAMETER1\r\n\r\n12345\r\n\r\n'. All pretty basic. So, what I have done is created a Communication Class. this call is called in it's own thread, and sends data back to the main form... and also allows me to send messages to it. Sending data is easy. Recieving is a bit more tricky. I have employed the use of the datarecieved event, and when ever data comes in, I echo that to my screen. My problem is this: When I send a command, I feel I am being very dodgy in my handling. What I am doing is, lets say I am sending 'QUERY PARAMETER1'. I send the command to the device, I then put 'PARAMETER1' into a global variable, and I do a Thread.Sleep(100). On the data received, I then have a bit of logic that checks the incoming data, and sees if the string CONTAINS the value in the global variable. As the reply may be 'QUERY PARAMETER1\r\n\r\n76767\r\n\r\n', it sees that it contains my parameter, parses the string, and returns the value I am looking for, but placing it into another global variable. My sending method was sleeping for 100ms. It then wakes, and checks the returned global variable. If it has data... then I'm happy, and I process the data. Problem is... if the sleep is too short.. it will fail. And I feel it's flaky.. putting stuff into variables.. then waiting... The other option is to use ReadLine instead, but that's very blocking. So I remove the data received method, and instead... just send the data... then call ReadLine(). That may give me better results. There's no time, except when we connect initially, that data comes from the device, without me requesting it. So, maybe ReadLine will be simpler and safer? Is this known as 'Blocking' reads? Also, can I set a timeout? Hopefully someone can guide me.

  Read the article

• wpftoolkit DataGridTemplateColumn Template binding

  - by Guillaume

  I want my datagrid columns to share a cell/celledit template. I have the solution do that (thanks to WPF DataGridTemplateColumn shared template?). Now what I would love to is improving the readability by avoiding all the node nesting. My current view looks like that: <wpftk:DataGrid ItemsSource="{Binding Tests}" AutoGenerateColumns="False"> <wpftk:DataGrid.Resources> <DataTemplate x:Key="CustomCellTemplate"> <TextBlock Text="{TemplateBinding Content}"/> </DataTemplate> <DataTemplate x:Key="CustomCellEditingTemplate"> <TextBox Text="{TemplateBinding Content}"></TextBox> </DataTemplate> </wpftk:DataGrid.Resources> <wpftk:DataGrid.Columns> <wpftk:DataGridTemplateColumn Header="Start Date"> <wpftk:DataGridTemplateColumn.CellTemplate> <DataTemplate> <ContentPresenter ContentTemplate="{StaticResource CustomCellTemplate}" Content="{Binding StartDate}"/> </DataTemplate> </wpftk:DataGridTemplateColumn.CellTemplate> <wpftk:DataGridTemplateColumn.CellEditingTemplate> <DataTemplate> <ContentPresenter ContentTemplate="{StaticResource CustomCellEditingTemplate}" Content="{Binding StartDate}"/> </DataTemplate> </wpftk:DataGridTemplateColumn.CellEditingTemplate> </wpftk:DataGridTemplateColumn> <!--and again the whole block above for each columns...--> </wpftk:DataGrid.Columns> </wpftk:DataGrid> What I would like to achieve is to bind the value at the DataGridTemplateColumn level and propagate it to the template level. Anyone know how to do that? What I tried to do is something like that: <wpftk:DataGrid ItemsSource="{Binding Tests}" AutoGenerateColumns="False"> <wpftk:DataGrid.Resources> <DataTemplate x:Key="CustomCellTemplate"> <TextBlock Text="{Binding}"/> </DataTemplate> <DataTemplate x:Key="CustomCellEditingTemplate"> <TextBox Text="{Binding}"></TextBox> </DataTemplate> </wpftk:DataGrid.Resources> <wpftk:DataGrid.Columns> <wpftk:DataGridTemplateColumn Header="Start Date" Binding="{Binding StartDate}" CellTemplate="{StaticResource CustomCellTemplate}" CellEditingTemplate="{StaticResource CustomCellEditingTemplate}"/> <wpftk:DataGridTemplateColumn Header="End Date" Binding="{Binding EndDate}" CellTemplate="{StaticResource CustomCellTemplate}" CellEditingTemplate="{StaticResource CustomCellEditingTemplate}"/> </wpftk:DataGrid.Columns> </wpftk:DataGrid> Obviously the binding porperty is not a valid property of the DataGridTemplateColumn but maybe by playing with the datacontext and some relative source could do the trick but frankly I can't find a way to implement that. Not sure if what I want is possible and i'm willing to accept a "no way you can do that" as an answer NOTE: The TextBlock/TextBox in the template is just for test (the real template is much more complex) DataGridTextColumn will not do the trick Thanks in advance

  Read the article

• How do I create something like a negated character class with a string instead of characters?

  - by Chas. Owens

  I am trying to write a tokenizer for Mustache in Perl. I can easily handle most of the tokens like this: #!/usr/bin/perl use strict; use warnings; my $comment = qr/ \G \{\{ ! (?<comment> .+? ) }} /xs; my $variable = qr/ \G \{\{ (?<variable> .+? ) }} /xs; my $text = qr/ \G (?<text> .+? ) (?= \{\{ | \z ) /xs; my $tokens = qr/ $comment | $variable | $text /x; my $s = do { local $/; <DATA> }; while ($s =~ /$tokens/g) { my ($type) = keys %+; (my $contents = $+{$type}) =~ s/\n/\\n/; print "type [$type] contents [$contents]\n"; } __DATA__ {{!this is a comment}} Hi {{name}}, I like {{thing}}. But I am running into trouble with the Set Delimiters directive: #!/usr/bin/perl use strict; use warnings; my $delimiters = qr/ \G \{\{ (?<start> .+? ) = [ ] = (?<end> .+?) }} /xs; my $comment = qr/ \G \{\{ ! (?<comment> .+? ) }} /xs; my $variable = qr/ \G \{\{ (?<variable> .+? ) }} /xs; my $text = qr/ \G (?<text> .+? ) (?= \{\{ | \z ) /xs; my $tokens = qr/ $comment | $delimiters | $variable | $text /x; my $s = do { local $/; <DATA> }; while ($s =~ /$tokens/g) { for my $type (keys %+) { (my $contents = $+{$type}) =~ s/\n/\\n/; print "type [$type] contents [$contents]\n"; } } __DATA__ {{!this is a comment}} Hi {{name}}, I like {{thing}}. {{(= =)}} If I change it to my $delimiters = qr/ \G \{\{ (?<start> [^{]+? ) = [ ] = (?<end> .+?) }} /xs; It works fine, but the point of the Set Delimiters directive is to change the delimiters, so the code will wind up looking like my $variable = qr/ \G $start (?<variable> .+? ) $end /xs; And it is perfectly valid to say {{{== ==}}} (i.e. change the delimiters to {= and =}). What I want, but maybe not what I need, is the ability to say something like (?:not starting string)+?. I figure I am just going to have to give up being clean about it and drop code into the regex to force it to match only what I want. I am trying to avoid that for four reasons: I don't think it is very clean. It is marked as experimental. I am not very familier with it (I think it comes down to (?{CODE}) and returning special values. I am hoping someone knows some other exotic feature that I am not familiar with that fits the situation better (e.g. (?(condition)yes-pattern|no-pattern)). Just to make things clear (I hope), I am trying to match a constant length starting delimiter followed by the shortest string that allows a match and does not contain the starting delimiter followed by a space followed by an equals sign followed by the shortest string that allows a match that ends with the ending delimiter.

  Read the article

• MIME "Content-Type" folding and parameter question regarding RFCs?

  - by BastiBense

  Hello, I'm trying to implement a basic MIME parser for the multipart/related in C++/Qt. So far I've been writing some basic parser code for headers, and I'm reading the RFCs to get an idea how to do everything as close to the specification as possible. Unfortunately there is a part in the RFC that confuses me a bit: From RFC882 Section 3.1.1: Each header field can be viewed as a single, logical line of ASCII characters, comprising a field-name and a field-body. For convenience, the field-body portion of this conceptual entity can be split into a multiple-line representation; this is called "folding". The general rule is that wherever there may be linear-white-space (NOT simply LWSP-chars), a CRLF immediately followed by AT LEAST one LWSP-char may instead be inserted. Thus, the single line Alright, so I simply parse a header field and if a CRLF follows with linear whitespace, I simply concat those in a useful manner to result in a single header line. Let's proceed... From RFC2045 Section 5.1: In the Augmented BNF notation of RFC 822, a Content-Type header field value is defined as follows: content := "Content-Type" ":" type "/" subtype *(";" parameter) ; Matching of media type and subtype ; is ALWAYS case-insensitive. [...] parameter := attribute "=" value attribute := token ; Matching of attributes ; is ALWAYS case-insensitive. value := token / quoted-string token := 1*<any (US-ASCII) CHAR except SPACE, CTLs, or tspecials> Okay. So it seems if you want to specify a Content-Type header with parameters, simple do it like this: Content-Type: multipart/related; foo=bar; something=else ... and a folded version of the same header would look like this: Content-Type: multipart/related; foo=bar; something=else Correct? Good. As I kept reading the RFCs, I came across the following in RFC2387 Section 5.1 (Examples): Content-Type: Multipart/Related; boundary=example-1 start="<[email protected]>"; type="Application/X-FixedRecord" start-info="-o ps" --example-1 Content-Type: Application/X-FixedRecord Content-ID: <[email protected]> [data] --example-1 Content-Type: Application/octet-stream Content-Description: The fixed length records Content-Transfer-Encoding: base64 Content-ID: <[email protected]> [data] --example-1-- Hmm, this is odd. Do you see the Content-Type header? It has a number of parameters, but not all have a ";" as parameter delimiter. Maybe I just didn't read the RFCs correctly, but if my parser works strictly like the specification defines, the type and start-info parameters would result in a single string or worse, a parser error. Guys, what's your thought on this? Just a typo in the RFCs? Or did I miss something? Thanks!

  Read the article

• A ResetBindings on a BindingSource of a Grid also resets ComboBox

  - by Tetsuo

  Hi there, I have a DataGridView with a BindingSource of products. This products have an enum (Producer). For the most text fields (to edit the product) below the DataGridView I have a method RefreshProduct which does a ResetBindings in the end to refresh the DataGridView. There is a ComboBox (cboProducer), too. If I run over the _orderBs.ResetBindings(false) it will reset my cboProducer outside the DataGridView, too. Could you please help me to avoid this? Here follows some code; maybe it is then better to understand. public partial class SelectProducts : UserControl { private AutoCompleteStringCollection _productCollection; private ProductBL _productBL; private OrderBL _orderBL; private SortableBindingList<ProductBE> _listProducts; private ProductBE _selectedProduct; private OrderBE _order; BindingSource _orderBs = new BindingSource(); public SelectProducts() { InitializeComponent(); if (_productBL == null) _productBL = new ProductBL(); if (_orderBL == null) _orderBL = new OrderBL(); if (_productCollection == null) _productCollection = new AutoCompleteStringCollection(); if (_order == null) _order = new OrderBE(); if (_listProducts == null) { _listProducts = _order.ProductList; _orderBs.DataSource = _order; grdOrder.DataSource = _orderBs; grdOrder.DataMember = "ProductList"; } } private void cmdGetProduct_Click(object sender, EventArgs e) { ProductBE product = _productBL.Load(txtProductNumber.Text); _listProducts.Add(product); _orderBs.ResetBindings(false); } private void grdOrder_SelectionChanged(object sender, EventArgs e) { if (grdOrder.SelectedRows.Count > 0) { _selectedProduct = (ProductBE)((DataGridView)(sender)).CurrentRow.DataBoundItem; if (_selectedProduct != null) { txtArticleNumber.Text = _selectedProduct.Article; txtPrice.Text = _selectedProduct.Price.ToString("C"); txtProducerNew.Text = _selectedProduct.ProducerText; cboProducer.DataSource = Enum.GetValues(typeof(Producer)); cboProducer.SelectedItem = _selectedProduct.Producer; } } } private void txtProducerNew_Leave(object sender, EventArgs e) { string property = CommonMethods.GetPropertyName(() => new ProductBE().ProducerText); RefreshProduct(((TextBoxBase)sender).Text, property); } private void RefreshProduct(object value, string property) { if (_selectedProduct != null) { double valueOfDouble; if (double.TryParse(value.ToString(), out valueOfDouble)) { value = valueOfDouble; } Type type = _selectedProduct.GetType(); PropertyInfo info = type.GetProperty(property); if (info.PropertyType.BaseType == typeof(Enum)) { value = Enum.Parse(info.PropertyType, value.ToString()); } try { Convert.ChangeType(value, info.PropertyType, new CultureInfo("de-DE")); info.SetValue(_selectedProduct, value, null); } catch (Exception ex) { throw new WrongFormatException("\"" + value.ToString() + "\" is not a valid value.", ex); } var produktFromList = _listProducts.Single(p => p.Position == _selectedProduct.Position); info.SetValue(produktFromList, value, null); _orderBs.ResetBindings(false); } } private void cboProducer_SelectedIndexChanged(object sender, EventArgs e) { var selectedIndex = ((ComboBox)(sender)).SelectedIndex; switch ((Producer)selectedIndex) { case Producer.ABC: txtProducerNew.Text = Constants.ABC; break; case Producer.DEF: txtProducerNew.Text = Constants.DEF; break; case Producer.GHI: txtProducerNew.Text = Constants.GHI; break; case Producer.Another: txtProducerNew.Text = String.Empty; break; default: break; } string property = CommonMethods.GetPropertyName(() => new ProductBE().Producer); RefreshProduct(selectedIndex, property); } }

  Read the article

• How do I get through proxy server environments for non-standard services?

  - by Ripred

  I'm not real hip on exactly what role(s) today's proxy servers can play and I'm learning so go easy on me :-) I have a client/server system I have written using a homegrown protocol and need to enhance the client side to negotiate its way out of a proxy environment. I have an existing client and server system written in C and C++ for the speed and a small amount of MFC in the client to handle the user interface. I have written both the server and client side of the system on Windows (the people I work for are mainly web developers using Windows everything - not a choice) sticking to Berkeley Sockets as it were via wsock32 for efficiency. The clients connect to the server through a nonstandard port (even though using port 80 is an option to get out of some environments but the protocol that goes over it isn't HTTP). The TCP connection(s) stay open for the duration of the clients participation in real time conferences. Our customer base is expanding to all kinds of networked environments. I have been able to solve a lot of problems by adding the ability to connect securely over port 443 and using secure sockets which allows the protocol to pass through a lot environments since the internal packets can't be sniffed. But more and more of our customers are behind a proxy server environment and my direct connections don't make it through. My old school understanding of proxy servers is that they act as a proxy for external HTML content over HTTP, possibly locally caching popular material for faster local access, and also allowing their IT staff to blacklist certain destination sites. Customer are complaining that my software doesn't recognize and easily navigate its way through their proxy environments but I'm finding it difficult to decide what my "best fit" solution should be. My software doesn't tear down the connection after each client request, and on top of that packets can come from either side at any time, basically your typical custom client/server system for a specific niche. My first reaction is "why can't they just add my servers addresses to their white list" but if there is a programmatic way I can get through without requiring their IT staff to help it is politically better and arguably a better solution anyway. Plus maybe I'm still not understanding the role and purpose of what proxy servers and environments have grown to be these days. My first attempt at a solution was to use WinInet with its various proxy capabilities to establish a connection over port 80 to my non-standard protocol server (which knows enough to recognize and answer a simple HTTP-looking GET request and answer it with a simple HTTP response page to get around some environments that employ initial packet sniffing (DPI)). I retrieved the actual SOCKET handle behind WinInet's HINTERNET request object and had hoped to use that in place of my software's existing SOCKET connection and hopefully not need to change much more on the client side. It initially seemed to be my solution but on further inspection it seems that the OS gets first-chance at the received data on this socket since when I get notified of events via the standard select(...) statement on the socket and query the size of the data available via ioctlsocket the call succeeds but returns 0 bytes available, the reads don't work and it goes downhill from there. Can someone tell me of a client-side library (commercial is fine) will let me get past these proxy server environments with as little user and IT staff help as possible? From what I read it has grown past SOCKS and I figure someone has to have solved this problem before me. Thanks for reading my long-winded question, Ripred

  Read the article

< Previous Page | 477 478 479 480 481 482 483 484 485 486 487 488  | Next Page >