Search Results

Search found 22641 results on 906 pages for 'use case'.

Page 754/906 | < Previous Page | 750 751 752 753 754 755 756 757 758 759 760 761  | Next Page >

  • Get active window title in X

    - by dutt
    I'm trying to get the title of the active window. The application is a background task so if the user has Eclipse open the function returns "Eclipse - blabla", so it's not getting the window title of my own window. I'm developing this in Python 2.6 using PyQt4. My current solution, borrowed and slightly modified from an old answer here at SO, looks like this: def get_active_window_title(): title = '' root_check = '' root = Popen(['xprop', '-root'], stdout=PIPE) if root.stdout != root_check: root_check = root.stdout for i in root.stdout: if '_NET_ACTIVE_WINDOW(WINDOW):' in i: id_ = i.split()[4] id_w = Popen(['xprop', '-id', id_], stdout=PIPE) for j in id_w.stdout: if 'WM_ICON_NAME(STRING)' in j: if title != j.split()[2]: return j.split("= ")[1].strip(' \n\"') It works for most windows, but not all. For example it can't find my kopete chat windows, or the name of the application i'm currently developing. My next try looks like this: def get_active_window_title(self): screen = wnck.screen_get_default() if screen == None: return "Could not get screen" window = screen.get_active_window() if window == None: return "Could not get window" title = window.get_name() return title; But for some reason window is always None. Does somebody have a better way of getting the current window title, or how to modify one of my ways, that works for all windows? Edit: In case anybody is wondering this is the way I found that seems to work for all windows. def get_active_window_title(self): root_check = '' root = Popen(['xprop', '-root'], stdout=PIPE) if root.stdout != root_check: root_check = root.stdout for i in root.stdout: if '_NET_ACTIVE_WINDOW(WINDOW):' in i: id_ = i.split()[4] id_w = Popen(['xprop', '-id', id_], stdout=PIPE) id_w.wait() buff = [] for j in id_w.stdout: buff.append(j) for line in buff: match = re.match("WM_NAME\((?P<type>.+)\) = (?P<name>.+)", line) if match != None: type = match.group("type") if type == "STRING" or type == "COMPOUND_TEXT": return match.group("name") return "Active window not found"

    Read the article

  • `enable_shared_from_this` has a non-virtual destructor

    - by Shtééf
    I have a pet project with which I experiment with new features of the upcoming C++0x standard. While I have experience with C, I'm fairly new to C++. To train myself into best practices, (besides reading a lot), I have enabled some strict compiler parameters (using GCC 4.4.1): -std=c++0x -Werror -Wall -Winline -Weffc++ -pedantic-errors This has worked fine for me. Until now, I have been able to resolve all obstacles. However, I have a need for enable_shared_from_this, and this is causing me problems. I get the following warning (error, in my case) when compiling my code (probably triggered by -Weffc++): base class ‘class std::enable_shared_from_this<Package>’ has a non-virtual destructor So basically, I'm a bit bugged by this implementation of enable_shared_from_this, because: A destructor of a class that is intended for subclassing should always be virtual, IMHO. The destructor is empty, why have it at all? I can't imagine anyone would want to delete their instance by reference to enable_shared_from_this. But I'm looking for ways to deal with this, so my question is really, is there a proper way to deal with this? And: am I correct in thinking that this destructor is bogus, or is there a real purpose to it?

    Read the article

  • Java: fastest way to do random reads on huge disk file(s)

    - by cocotwo
    I've got a moderately big set of data, about 800 MB or so, that is basically some big precomputed table that I need to speed some computation by several orders of magnitude (creating that file took several mutlicores computers days to produce using an optimized and multi-threaded algo... I do really need that file). Now that it has been computed once, that 800MB of data is read only. I cannot hold it in memory. As of now it is one big huge 800MB file but splitting in into smaller files ain't a problem if it can help. I need to read about 32 bits of data here and there in that file a lot of time. I don't know before hand where I'll need to read these data: the reads are uniformly distributed. What would be the fastest way in Java to do my random reads in such a file or files? Ideally I should be doing these reads from several unrelated threads (but I could queue the reads in a single thread if needed). Is Java NIO the way to go? I'm not familiar with 'memory mapped file': I think I don't want to map the 800 MB in memory. All I want is the fastest random reads I can get to access these 800MB of disk-based data. btw in case people wonder this is not at all the same as the question I asked not long ago: http://stackoverflow.com/questions/2346722/java-fast-disk-based-hash-set

    Read the article

  • Viewing recently edited etherpads (note new 'etherpad' tag for open sourced etherpad code!)

    - by dreeves
    Prescript: The amazing etherpad was recently open sourced. Get it here: http://code.google.com/p/etherpad. This is the first question that I know of on StackOverflow about the etherpad code. If you're part of the etherpad open source community, you might want to subscribe to the RSS feed for questions tagged 'etherpad' just in case this catches on! My actual question, which assumes you have etherpad installed on your own server: First, here's a query to view recently edited pads: SELECT id,lastWriteTime,creationTime,headRev FROM PAD_SQLMETA ORDER BY lastWriteTime, headRev; Or, if you want to run it from a unix prompt: mysql -u root -pPASSWD etherpad -e "select id,lastWriteTime,creationTime,headRev from PAD_SQLMETA order by lastWriteTime, headRev" That's handy, however lastWriteTime actually gets updated every time someone so much as views a pad in their browser. I'd rather sort the pads by when they were actually last edited. There's probably a fancy SQL query involving a join with another table that would show actual last edit time. Does anyone know what that is? Alternatively, you could have a script that notices when headRev changes but that doesn't seem like the cleanest way to do it.

    Read the article

  • Django, url tag in template doesn't work: NoReverseMatch

    - by Lukasz Jocz
    I've encountered a problem with generating reverse url in templates in django. I'm trying to solve it since a few hours and I have no idea what the problem might be. URL reversing works great in models and views: # like this in models.py @models.permalink def get_absolute_url(self): return ('entry', (), { 'entry_id': self.entry.id, }) # or this in views.py return HttpResponseRedirect(reverse('entry',args=(entry_id,))) but when I'm trying to make it in template I get such an error: NoReverseMatch at /entry/1/ Reverse for ''add_comment'' with arguments '(1L,)' and keyword arguments '{}' not found. My file structure looks like this: project/ +-- frontend ¦   +-- models.py ¦   +-- urls.py ¦   +-- views.py +-- settings.py +-- templates ¦   +-- add_comment.html ¦   +-- entry.html +-- utils ¦   +-- with_template.py +-- wsgi.py My urls.py: from project.frontend.views import * from django.conf.urls import patterns, include, url urlpatterns = patterns('project.frontend.views', url(r'^entry/(?P<entry_id>\d+)/', 'entry', name="entry"), (r'^entry_list/', 'entry_list'), Then entry_list.html: {% extends "base.html" %} {% block content %} {% for entry in entries %} {% url 'entry' entry.id %} {% endfor %} {% endblock %} In views.py I have: @with_template def entry(request, entry_id): entry = Entry.objects.get(id=entry_id) entry.comments = entry.get_comments() return locals() where with_template is following decorator(but I don't think this is a case): class TheWrapper(object): def __init__(self, default_template_name): self.default_template_name = default_template_name def __call__(self, func): def decorated_func(request, *args, **kwargs): extra_context = kwargs.pop('extra_context', {}) dictionary = {} ret = func(request, *args, **kwargs) if isinstance(ret, HttpResponse): return ret dictionary.update(ret) dictionary.update(extra_context) return render_to_response(dictionary.get('template_name', self.default_template_name), context_instance=RequestContext(request), dictionary=dictionary) update_wrapper(decorated_func, func) return decorated_func if not callable(arg): return TheWrapper(arg) else: default_template_name = ''.join([ arg.__name__, '.html']) return TheWrapper(default_template_name)(arg) Do you have any idea, what may cause the problem? Great thanks in advance!

    Read the article

  • How to define default values optional fields in play framework forms?

    - by natalinobusa
    I am implementing a web api using the scala 2.0.2 play framework. I would like to extract and validate a number of get parameters. And for this I am using a play "form" which allows me to define optional fields. Problem: For those optional fields, I need to define a default value if the parameter is not passed. The code is intended to parse correctly these three use cases: /test?top=abc (error, abc is not an integer) /test?top=123 (valid, top is 123) /test (valid, top is 42 (default value)) I have come up with the following code: def test = Action { implicit request => case class CData(top:Int) val p = Form( mapping( "top" -> optional(number) )((top) => CData($top.getOrElse(42))) ((cdata:CData) => Some(Some(cdata.top))) ).bindFromRequest() Ok("all done.") } The code works, but it's definitely not elegant. There is a lot of boiler plate going on just to set up a default value for a missing request parameter. Can anyone suggest a cleaner and more coincise solution?

    Read the article

  • The application has stopped unexpectedly: How to Debug?

    - by Android Eve
    Please note, unlike many other questions having the subject title "application has stopped unexpectedly", I am not asking for troubleshooting a particular problem. Rather, I am asking for an outline of the best strategy for an Android/Eclipse/Java rookie to tackle this formidable task of digesting huge amounts of information in order to develop (and debug!) a simple Android application. In my case, I took the sample skeleton app from the SDK, modified it slightly and what did I get the moment I try to run it? The application (process.com.example.android.skeletonapp) has stopped unexpectedly. Please try again. OK, so I know that I have to look LogCat. It's full of timestamped lines staring at me... What do I do now? What do I need to look for? Is there a way to single-step the program, to find the statement that makes the app crash? (I thought Java programs never crash, but apparently I was mistaken) How do I place a breakpoint? Can you recommend an Android debug tutorial online, other than this one?

    Read the article

  • How to face observable object containing an observable field

    - by iseek
    Hello, I need a hint concerning MVC and Observer-Pattern. For example a model contains the classes "Address" and "Person". The Address class contains the fields street:String, zipcode:String, location:String. Whereas the Person class contains the fields name:String, firstName:String, address:Address. My approach so far looks something like this: Both, Address and Person are observable. If one of their setters is being called, I validate whether the current value and new value differ. Only in this case an update event is fired. The event contains the source, the name of the changed field, the old and the new value. The class for the view contains text fields to display and edit the information of a person: name, firstname, street, zipcode, location. It knows the Person model and is an subscribed observer for the person. So it gets the update events from the person object. My questions concerns the address field from type Address in the person class, since an address is observable on its own. If the view gets an update event from person when a new address has been set, I can update all of the address related fields in the view. But what if a field of the address changes? Should the view also register for update events from the address? Any hints about common design approaches would be appreciated. Greetings.

    Read the article

  • Need help extrapolating Java code

    - by Berlioz
    If anyone familiar with Rebecca Wirfs-Brock, she has a piece of Java code found in her book titled, Object Design: Roles, Responsibilities, and Collaborations. Here is the quote Applying Double Dispatch to a Specific Problem To implement the game Rock, Paper, Scissors we need to write code that determines whether one object “beats” another. The game has nine possible outcomes based on the three kinds of objects. The number of interactions is the cross product of the kinds of objects. Case or switch statements are often governed by the type of data that is being operated on. The object-oriented language equivalent is to base its actions on the class of some other object. In Java, it looks like this Here is the piece of Java code on page 16 ' import java.util.*; import java.lang.*; public class Rock { public static void main(String args[]) { } public static boolean beats(GameObject object) { if (object.getClass.getName().equals("Rock")) { result = false; } else if (object.getClass.getName().equals("Paper")) { result = false; } else if(object.getClass.getName().equals("Scissors")) { result = true; } return result; } }' ===This is not a very good solution. First, the receiver needs to know too much about the argument. Second, there is one of these nested conditional statements in each of the three classes. If new kinds of objects could be added to the game, each of the three classes would have to be modified. Can anyone share with me how to get this "less than optimal" piece of code to work in order to see it 'working'. She proceeds to demonstrate a better way, but I will spare you. Thanks

    Read the article

  • Querying the size of a drive on a remote server is giving me an error

    - by Testifier
    Here's what I have: public static bool DriveHasLessThanTenPercentFreeSpace(string server) { long driveSize = 0; long freeSpace = 0; var oConn = new ConnectionOptions {Username = "username", Password = Settings.Default.SQLServerAdminPassword}; var scope = new ManagementScope("\\\\" + server + "\\root\\CIMV2", oConn); //connect to the scope scope.Connect(); //construct the query var query = new ObjectQuery("SELECT FreeSpace FROM Win32_LogicalDisk where DeviceID = 'D:'"); //this class retrieves the collection of objects returned by the query var searcher = new ManagementObjectSearcher(scope, query); //this is similar to using a data adapter to fill a data set - use an instance of the ManagementObjectSearcher to get the collection from the query and store it ManagementObjectCollection queryCollection = searcher.Get(); //iterate through the object collection and get what you're looking for - in my case I want the FreeSpace of the D drive foreach (ManagementObject m in queryCollection) { //the FreeSpace value is in bytes freeSpace = Convert.ToInt64(m["FreeSpace"]); //error happens here! driveSize = Convert.ToInt64(m["Size"]); } long percentFree = ((freeSpace / driveSize) * 100); if (percentFree < 10) { return true; } return false; } This line of code is giving me an error: driveSize = Convert.ToInt64(m["Size"]); The error says: ManagementException was unhandled by user code Not found I'm assuming the query to get the drive size is wrong. Please note that I AM getting the freeSpace value at the line: freeSpace = Convert.ToInt64(m["FreeSpace"]); So I know the query IS working for freeSpace. Can anyone give me a hand?

    Read the article

  • Codeigniter only loads the default controller

    - by fh47331
    I am very new to CodeIgniter, but have been programming PHP for ages. I'm writing some software at the moment and using CI for the first time with it. The default controller is set to the first controller I want to action call 'login' (the controller is login.php, the view is login.php. When the form is submitted it calls the 'authenticate' controller. This executes fine, process the login data correctly and then does a redirect command (without any output to the screen prior) to the next page in this case 'newspage'. The problem is that the redirect, never reaches 'newspage' but the default controller runs again. It doesn't matter what I put ... ht tp://domain.name/anything ... (yes im using .htaccess to remove the index.php) the anything never gets called, just the default controller. I have left the standard 'welcome.php' controller and 'welcome_message.php' in the folders and even putting ht tp://domain.name/welcome all I get is the login screen! (Obviously there shouldn't be a space between the http - thats just done so it does not show as a hyperlink!) Can anyone tell me what i've done wrong!

    Read the article

  • How long is the time frame between context switches on Windows?

    - by mattcodes
    Reading CLR via C# 2.0 (I dont have 3.0 with me at the moment) Is this still the case: If there is only one CPU in a computer, only one thread can run at any one time. Windows has to keep track of the thread objects, and every so often, Windows has to decide which thread to schedule next to go to the CPU. This is additional code that has to execute once every 20 milliseconds or so. When Windows makes a CPU stop executing one thread's code and start executing another thread's code, we call this a context switch. A context switch is fairly expensive because the operating system has to: So circa CLR via C# 2.0 lets say we are on Pentium 4 2.4ghz 1 core non-HT, XP. Every 20 milliseconds? Where a CLR thread or Java thread is mapped to an OS thread only a maximum of 50 threads per second may get a chance to to run? I've read that context switching is very fast in mircoseconds here on SO, but how often roughly (magnitude style guesses) will say a modest 5 year old server Windows 2003 Pentium Xeon single core give the OS the opportunity to context switch? 20ms in the right area? I dont need exact figures I just want to be sure that's in the right area, seems rather long to me.

    Read the article

  • Matlab fft function

    - by CTZStef
    The code below is from the Matlab 2011a help about fft function. I think there is a problem here : why do they multiply t(1:50) by Fs, and then say it's time in millisecond ? Certainly, it happens to be true in this very particular case, but change the value of Fs to, say, 2000, and it won't work anymore, obviously because of this factor of 2. Right ? Quite misleading, isn't it ? What do I miss ? Fs = 1000; % Sampling frequency T = 1/Fs; % Sample time L = 1000; % Length of signal t = (0:L-1)*T; % Time vector % Sum of a 50 Hz sinusoid and a 120 Hz sinusoid x = 0.7*sin(2*pi*50*t) + sin(2*pi*120*t); y = x + 2*randn(size(t)); % Sinusoids plus noise plot(Fs*t(1:50),y(1:50)) title('Signal Corrupted with Zero-Mean Random Noise') xlabel('time (milliseconds)') Clearer with this : fs = 2000; % Sampling frequency T = 1 / fs; % Sample time L = 1000; % Length of signal t2 = (0:L-1)*T; % Time vector f = 50; % signal frequency s2 = sin(2*pi*f*t2); figure, plot(fs*t2(1:50),s2(1:50)); % NOT good figure, plot(t2(1:50),s2(1:50)); % good

    Read the article

  • What are salesforce.com and Apex like as an application development platform?

    - by mhollers
    I have recently discovered that salesforce.com is much more than an online CRM after coming across a Morrison's Case Study in which they develop a works management application. I've been trying it out with a view to recreating our own Works Management system on the platform. My background is in Microsoft and .Net, and the obvious 1st choice would be asp.net. However, there's only really myself with .net experience and my manager with a more legacy Synergy programming background, and I am self taught and am looking at evaluating other RAD options (eg Ironspeed). the nature of the business is in the main 2-5 concurrent construction type contracts that run for 3-5 yrs each, each requiring 15-50 system users. Traditionally we have used our character based Works Mangement system for everything and tweaked it for each contract. The Salesforce licensing model on the face of it suits this sort of flexibilty, but I'm worried about the development flexibilty/learning curve and all the issues that surround lock-in. There doesn't seem to be much neutral sober analysis of the platform on the web that isn't salesforce's own material/blogs Has anyone any experience of developing an application on salesforce as compared to the more 'traditional' .Net route?

    Read the article

  • Is there any point in using a volatile long?

    - by Adamski
    I occasionally use a volatile instance variable in cases where I have two threads reading from / writing to it and don't want the overhead (or potential deadlock risk) of taking out a lock; for example a timer thread periodically updating an int ID that is exposed as a getter on some class: public class MyClass { private volatile int id; public MyClass() { ScheduledExecutorService execService = Executors.newScheduledThreadPool(1); execService.scheduleAtFixedRate(new Runnable() { public void run() { ++id; } }, 0L, 30L, TimeUnit.SECONDS); } public int getId() { return id; } } My question: Given that the JLS only guarantees that 32-bit reads will be atomic is there any point in ever using a volatile long? (i.e. 64-bit). Caveat: Please do not reply saying that using volatile over synchronized is a case of pre-optimisation; I am well aware of how / when to use synchronized but there are cases where volatile is preferable. For example, when defining a Spring bean for use in a single-threaded application I tend to favour volatile instance variables, as there is no guarantee that the Spring context will initialise each bean's properties in the main thread.

    Read the article

  • Is private method in spring service implement class thread safe

    - by Roger Ray
    I got a service in an project using Spring framework. public class MyServiceImpl implements IMyService { public MyObject foo(SomeObject obj) { MyObject myobj = this.mapToMyObject(obj); myobj.setLastUpdatedDate(new Date()); return myobj; } private MyObject mapToMyObject(SomeObject obj){ MyObject myojb = new MyObject(); ConvertUtils.register(new MyNullConvertor(), String.class); ConvertUtils.register(new StringConvertorForDateType(), Date.class); BeanUtils.copyProperties(myojb , obj); ConvertUtils.deregister(Date.class); return myojb; } } Then I got a class to call foo() in multi-thread; There goes the problem. In some of the threads, I got error when calling BeanUtils.copyProperties(myojb , obj); saying Cannot invoke com.my.MyObject.setStartDate - java.lang.ClassCastException@2da93171 obviously, this is caused by ConvertUtils.deregister(Date.class) which is supposed to be called after BeanUtils.copyProperties(myojb , obj);. It looks like one of the threads deregistered the Date class out while another thread was just about to call BeanUtils.copyProperties(myojb , obj);. So My question is how do I make the private method mapToMyObject() thread safe? Or simply make the BeanUtils thread safe when it's used in a private method. And will the problem still be there if I keep the code this way but instead I call this foo() method in sevlet? If many sevlets call at the same time, would this be a multi-thread case as well?

    Read the article

  • Using list() to extract a data.table inside of a function

    - by Nathan VanHoudnos
    I must admit that the data.table J syntax confuses me. I am attempting to use list() to extract a subset of a data.table as a data.table object as described in Section 1.4 of the data.table FAQ, but I can't get this behavior to work inside of a function. An example: require(data.table) ## Setup some test data set.seed(1) test.data <- data.table( X = rnorm(10), Y = rnorm(10), Z = rnorm(10) ) setkey(test.data, X) ## Notice that I can subset the data table easily with literal names test.data[, list(X,Y)] ## X Y ## 1: -0.8356286 -0.62124058 ## 2: -0.8204684 -0.04493361 ## 3: -0.6264538 1.51178117 ## 4: -0.3053884 0.59390132 ## 5: 0.1836433 0.38984324 ## 6: 0.3295078 1.12493092 ## 7: 0.4874291 -0.01619026 ## 8: 0.5757814 0.82122120 ## 9: 0.7383247 0.94383621 ## 10: 1.5952808 -2.21469989 I can even write a function that will return a column of the data.table as a vector when passed the name of a column as a character vector: get.a.vector <- function( my.dt, my.column ) { ## Step 1: Convert my.column to an expression column.exp <- parse(text=my.column) ## Step 2: Return the vector return( my.dt[, eval(column.exp)] ) } get.a.vector( test.data, 'X') ## [1] -0.8356286 -0.8204684 -0.6264538 -0.3053884 0.1836433 0.3295078 ## [7] 0.4874291 0.5757814 0.7383247 1.5952808 But I cannot pull a similar trick for list(). The inline comments are the output from the interactive browser() session. get.a.dt <- function( my.dt, my.column ) { ## Step 1: Convert my.column to an expression column.exp <- parse(text=my.column) ## Step 2: Enter the browser to play around browser() ## Step 3: Verity that a literal X works: my.dt[, list(X)] ## << not shown >> ## Step 4: Attempt to evaluate the parsed experssion my.dt[, list( eval(column.exp)] ## Error in `rownames<-`(`*tmp*`, value = paste(format(rn, right = TRUE), (from data.table.example.R@1032mCJ#7) : ## length of 'dimnames' [1] not equal to array extent return( my.dt[, list(eval(column.exp))] ) } get.a.dt( test.data, "X" ) What am I missing? Update: Due to some confusion as to why I would want to do this I wanted to clarify. My use case is when I need to access a data.table column when when I generate the name. Something like this: set.seed(2) test.data[, X.1 := rnorm(10)] which.column <- 'X' new.column <- paste(which.column, '.1', sep="") get.a.dt( test.data, new.column ) Hopefully that helps.

    Read the article

  • Entity framework with Linq to Entities performance

    - by mare
    If I have a static method like this public static string GetTicClassificationTitle(string classI, string classII, string classIII) { using (TicDatabaseEntities ticdb = new TicDatabaseEntities()) { var result = from classes in ticdb.Classifications where classes.ClassI == classI where classes.ClassII == classII where classes.ClassIII == classIII select classes.Description; return result.FirstOrDefault(); } } and use this method in various places in foreach loops or just plain calling it numerous times, does it create and open new connection every time? If so, how can I tackle this? Should I cache the results somewhere, like in this case, I would cache the entire Classifications table in Memory Cache? And then do queries vs this cached object? Or should I make TicDatabaseEntities variable static and initialize it at class level? Should my class be static if it contains only static methods? Because right now it is not.. Also I've noticed that if I return result.First() instead of FirstOrDefault() and the query does not find a match, it will issue an exception (with FirstOrDefault() there is no exception, it returns null). Thank you for clarification.

    Read the article

  • Send Special Keys to Gtk.VteTerminal

    - by Ubersoldat
    Hi I have this OSS Project called Monocaffe connections manager which uses the Gtk.VteTerminal widget from PyGTK. A nice feature is that it allows the users to send commands to different servers' consoles (cluster mode) using a Gtk.TextView for the input. The way I send key strokes to each Gtk.VteTerminal is by using the feed_child method. For common keys there's no problem: I simply feed what the TextView receives to all the terminals, but when doing so with special keys I get into a little trouble. For "Return" I catch the event and feed the terminal a '\n'. For back-space is the same, catch the event and feed a '\b'. def cluster_backspace(self, widget): return self.cluster_send_key('\b') The problem comes with other keys like Tab, Arrows, Esc which I don't know how to feed as str to the terminal to recognize them. In the case of Esc is a real pain, because the users can edit the same file on different servers using vi, but cannot escape insert mode. Anyway, I'm not looking for a complete solution, just ideas since I've ran out of them. Thanks.

    Read the article

  • Issue with GCD and too many threads

    - by dariaa
    I have an image loader class which provided with NSURL loads and image from the web and executes completion block. Code is actually quite simple - (void)downloadImageWithURL:(NSString *)URLString completion:(BELoadImageCompletionBlock)completion { dispatch_async(_queue, ^{ // dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{ UIImage *image = nil; NSURL *URL = [NSURL URLWithString:URLString]; if (URL) { image = [UIImage imageWithData:[NSData dataWithContentsOfURL:URL]]; } dispatch_async(dispatch_get_main_queue(), ^{ completion(image, URLString); }); }); } When I replace dispatch_async(_queue, ^{ with commented out dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{ Images are loading much faster, wich is quite logical (before that images would be loaded one at a time, now a bunch of them are loading simultaneously). My issue is that I have perhaps 50 images and I call downloadImageWithURL:completion: method for all of them and when I use global queue instead of _queue my app eventually crashes and I see there are 85+ threads. Can the problem be that my calling dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0) 50 times in a row makes GCD create too many threads? I thought that gcd handles all the treading and makes sure the number of threads is not huge, but if it's not the case is there any way I can influence number of threads?

    Read the article

  • XPath and XML: Multiple namespaces

    - by emragins
    So I have a document that looks like <a xmlns="uri1" xmlns:pre2="uri2"> <b xmlns:pre3="uri3"> <pre3:c> <stuff></stuff> <goes></goes> <here></here> </pre3:c> <pre3:d xmlns="uri4"> <under></under> <the></the> <tree></tree> </pre3:d> </b> </a> I want an xpath expression that will get me <under>. This has a namespaceURI of uri4. Right now my expression looks like: //ns:a/ns:b/pre3:d/pre4:under I have the namespace manager add 'ns' for the default namespace (uri1 in this case) and I have it defined with pre2, pre3, and pre4 for uri2, uri3, and uri4 respectively. I get the error "Expression must evaluate to a node-set." I know that the node exists. I know that everything up until the pre4:under in my xpath works fine as I use it in the rest of the document with no issues. It's the additional pre4:under that causes the error, and I'm not sure why. Any ideas? Thanks.

    Read the article

  • Should frontend and backend be handled by different controllers?

    - by DR
    In my previous learning projects I always used a single controller, but now I wonder if that is good practice or even always possible. In all RESTful Rails tutorials the controllers have a show, an edit and an index view. If an authorized user is logged on, the edit view becomes available and the index view shows additional data manipulation controls, like a delete button or a link to the edit view. Now I have a Rails application which falls exactly into this pattern, but the index view is not reusable: The normal user sees a flashy index page with lots of pictures, complex layout, no Javascript requirement, ... The Admin user index has a completly different minimalistic design, jQuery table and lots of additional data, ... Now I'm not sure how to handle this case. I can think of the following: Single controller, single view: The view is split into two large blocks/partials using an if statement. Single controller, two views: index and index_admin. Two different controllers: BookController and BookAdminController None of these solutions seems perfect, but for now I'm inclined to use the 3rd option. What's the preferred way to do this?

    Read the article

  • "Invalid use of Null" when using Str() with a Null Recordset field, but Str(Null) works fine

    - by Mike Spross
    I'm banging my head against the wall on this one. I was looking at some old database reporting code written in VB6 and case across this line (the code is moving data from a "source" database into a reporting database): rsTarget!VehYear = Trim(Str(rsSource!VehYear)) When rsSource!VehYear is Null, the above line generates an "Invalid use of Null" run-time error. If I break on the above line and type the following in the Immediate pane: ?rsSource!VehYear It outputs Null. Fine, that makes sense. Next, I try to reproduce the error: ?Str(rsSource!VehYear) I get an "Invalid use of Null" error. However, if I type the following into the Immediate window: ?Str(Null) I don't get an error. It simply outputs Null. If I repeat the same experiment with Trim() instead of Str(), everything works fine. ?Trim(rsSource!VehYear) returns Null, as does ?Trim(Null). No run-time errors. So, my question is, how can Str(rsSource!VehYear) possibly throw an "Invalid use of Null" error when Str(Null) does not, when I know that rsSource!VehYear is equal to Null?

    Read the article

  • Using Relative Paths to Load Resources in Cocoa/C++

    - by moka
    I am currently working directly with Cocoa for the first time to built a screen saver. Now I came across a problem when trying to load resources from within the .saver bundle. I basically have a small C++ wrapper class to load .exr files using freeImage. This works as long as I use absoulte paths, but that's not very useful, is it? So, basically, I tried everything: putting the .exr file at the level of the .saver bundle itself, inside the bundles Resources folder, and so on. Then I simply tried to load the .exr like this, but without success: particleTex = [self loadExrTexture:@"ball.exr"]; I also tried making it go to the .saver bundles location like this: particleTex = [self loadExrTexture:@"../../../ball.exr"]; ...to maybe load the .exr from that location, but without success. I then came across this: NSString * path = [[NSBundle mainBundle] pathForResource:@"ball" ofType:@"exr"]; const char * pChar = [path UTF8String]; ...which seems to be a common way to find resources in Cocoa, but for some reason it's empty in my case. Any ideas about that? I really tried out anything that came to my mind without success so I would be glad about some input!

    Read the article

  • How to get Amazon s3 PHP SDK working?

    - by JakeRow123
    I'm trying to set up s3 for the first time and trying to run the sample file that comes with the PHP sdk that creates a bucket and attempts to upload some demo files to it. But this is the error I am getting: The difference between the request time and the current time is too large. I read on another question on SO that this is because Amazon determines a valid request by comparing the times between the server and the client, that the 2 must be within a 15 min span of one another. Now here is the problem. My laptop's time is 12:30AM June 8, 2012 at the moment. On my server I created a file called servertime.php and placed this code in that file: <?php print strftime('%c'); ?> and the output is: Fri Jun 8 00:31:22 2012 It looks like the day is correct but I don't know what to make of 00:31:22. In any case, how is it possible to always make sure the time between the client and server is within a 15 minute window of one another. What if I have a user in China who wishes to upload a file on my site which uses s3 for the cdn. Then the time difference would be over a day. How can I make sure all my user's times are within 15 minutes of my server time? What if the user is in the U.S. but the time on their machine is misconfigured. Basically how to get s3 bucket creation and upload to work?

    Read the article

< Previous Page | 750 751 752 753 754 755 756 757 758 759 760 761  | Next Page >