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  • How can I specify dependencies in the manifest file and then to include it into my .jar file?

    - by Roman
    I generated .class files by the following command: javac -cp \directoryName\external.jar myPackageDirectory\First.java myPackageDirectory\Second.java I needed to use -cp during compilation and name of .jar file of an "external" library (external.jar) to be able to use this library from my code. Using my .class files I have generated my .jar file in the following way: jar cfm app.jar manifest.txt myPackageDirectory\*.class manifest.txt contains just one line: Main-Class: myPackageName.First My problem is that I am not sure that I will be able to run my .jar file on other computers. I think so because during the compilation I specified the location of the .jar file of the external library. So, my .class files (included into the .jar file will try to find the .jar file of the external library in a specific directory and there is no guaranty that that the .jar file of the external library will be in the same directory as on the my computer. I heard that the above problem can be solved by a usage of a MANIFEST file that I include in my own jar, and which will list dependency locations but I do not understand how it works. I do need to specify location of the "external.jar" at the compilation stage (otherwise the compiler complains).

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  • I have a serious problem to use 'happle' in xcode project.

    - by Daniel K
    Hello. I am a korean student, and I'm trying to develop a iphone application. I want to make the application which will shows contents of Web board, which is belong to some website. I will use 'UITableViewController", and the names of contents have to be displayed on table view. I heard that if I want to scrap the text on webpage, I have to use 'parser'. However, Iphone SDKs provide only the parser for xml webpage, NSXmlParser. In my acknowledges, NSXmlParser is not for HTML webpage, so it doesn't provide HTML parsing. If there is any way to parse HTML page with NSXmlParser, I want to know how to use that. Anyway, I found a simple and good HTML parser, 'happle', through searching on google. I tried to add the sources of happle on my xcode project, and I also add the libxml2.2.dylib, and I even set up 'Header search paths' and 'Other Linker Flags'. However It doesn't work. The Compiler show a error message : "No such file in dictionary". In my opinion, there is no frameworks file in my computer, so I tried to set up 'libxml2 frameworks' many times, but I coundn't success. please help me how to parse HTML page and how to set up libxml2... It really urgent. p.s. please forgive my ugly English

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  • How to debug KVO

    - by user8472
    In my program I use KVO manually to observe changes to values of object properties. I receive an EXC_BAD_ACCESS signal at the following line of code inside a custom setter: [self willChangeValueForKey:@"mykey"]; The weird thing is that this happens when a factory method calls the custom setter and there should not be any observers around. I do not know how to debug this situation. Update: The way to list all registered observers is observationInfo. It turned out that there was indeed an object listed that points to an invalid address. However, I have no idea at all how it got there. Update 2: Apparently, the same object and method callback can be registered several times for a given object - resulting in identical entries in the observed object's observationInfo. When removing the registration only one of these entries is removed. This behavior is a little counter-intuitive (and it certainly is a bug in my program to add multiple entries at all), but this does not explain how spurious observers can mysteriously show up in freshly allocated objects (unless there is some caching/reuse going on that I am unaware of). Modified question: How can I figure out WHERE and WHEN an object got registered as an observer? Update 3: Specific sample code. ContentObj is a class that has a dictionary as a property named mykey. It overrides: + (BOOL)automaticallyNotifiesObserversForKey:(NSString *)theKey { BOOL automatic = NO; if ([theKey isEqualToString:@"mykey"]) { automatic = NO; } else { automatic=[super automaticallyNotifiesObserversForKey:theKey]; } return automatic; } A couple of properties have getters and setters as follows: - (CGFloat)value { return [[[self mykey] objectForKey:@"value"] floatValue]; } - (void)setValue:(CGFloat)aValue { [self willChangeValueForKey:@"mykey"]; [[self mykey] setObject:[NSNumber numberWithFloat:aValue] forKey:@"value"]; [self didChangeValueForKey:@"mykey"]; } The container class has a property contents of class NSMutableArray which holds instances of class ContentObj. It has a couple of methods that manually handle registrations: + (BOOL)automaticallyNotifiesObserversForKey:(NSString *)theKey { BOOL automatic = NO; if ([theKey isEqualToString:@"contents"]) { automatic = NO; } else { automatic=[super automaticallyNotifiesObserversForKey:theKey]; } return automatic; } - (void)observeContent:(ContentObj *)cObj { [cObj addObserver:self forKeyPath:@"mykey" options:0 context:NULL]; } - (void)removeObserveContent:(ContentObj *)cObj { [cObj removeObserver:self forKeyPath:@"mykey"]; } - (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context { if (([keyPath isEqualToString:@"mykey"]) && ([object isKindOfClass:[ContentObj class]])) { [self willChangeValueForKey:@"contents"]; [self didChangeValueForKey:@"contents"]; } } There are several methods in the container class that modify contents. They look as follows: - (void)addContent:(ContentObj *)cObj { [self willChangeValueForKey:@"contents"]; [self observeDatum:cObj]; [[self contents] addObject:cObj]; [self didChangeValueForKey:@"contents"]; } And a couple of others that provide similar functionality to the array. They all work by adding/removing themselves as observers. Obviously, anything that results in multiple registrations is a bug and could sit somewhere hidden in these methods. My question targets strategies on how to debug this kind of situation. Alternatively, please feel free to provide an alternative strategy for implementing this kind of notification/observer pattern.

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  • Synthetic click doesn't switch application's menu bar (Mac OS X)

    - by Rok
    Hi. I'm developing some sort of air mouse application for iPhone platform. This applications connects to one computer service which generates mouse events on Mac OS X. I'm generating this events with CGEventCreateMouseEvent() and CGEventPost(). But I've encountered one problem. Let's say you are using Safari and then you click on free desktop space. If you do this with regular mouse it will hide Safari's top menu bar and show Finder menu bar. But on these synthetic events it doesn't act like that. Do I have to post some other event or set some additional properties? Here is my code for mouse up, mouse down: - (void)mouseUp:(int)button { int type = (button == LEFT_BUTTON) ? kCGEventLeftMouseUp : kCGEventRightMouseUp; int mouseButton = (button == LEFT_BUTTON) ? kCGMouseButtonLeft : kCGMouseButtonRight; leftMouseDown = (button == LEFT_BUTTON) ? NO : leftMouseDown; rightMouseDown = (button == RIGHT_BUTTON) ? NO : rightMouseDown; CGEventSourceRef source = CGEventSourceCreate(kCGEventSourceStateHIDSystemState); CGEventRef event = CGEventCreateMouseEvent (source, type, CGSCurrentInputPointerPosition(), mouseButton); CGEventSetType(event, type); CGEventPost(kCGHIDEventTap, event); CFRelease(event); } - (void)mouseDown:(int)button { int type = (button == LEFT_BUTTON) ? kCGEventLeftMouseDown : kCGEventRightMouseDown; int mouseButton = (button == LEFT_BUTTON) ? kCGMouseButtonLeft : kCGMouseButtonRight; leftMouseDown = (button == LEFT_BUTTON) ? YES : leftMouseDown; rightMouseDown = (button == RIGHT_BUTTON) ? YES : rightMouseDown; CGEventSourceRef source = CGEventSourceCreate(kCGEventSourceStateHIDSystemState); CGEventRef event = CGEventCreateMouseEvent (source, type, CGSCurrentInputPointerPosition(), mouseButton); CGEventSetType(event, type); CGEventPost(kCGHIDEventTap, event); CFRelease(event); }

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  • Why Can't Businesses Upgrade their Browsers from IE6/IE7?

    - by viatropos
    I have read lots these past few weeks on IE6, seeing if it was really that bad to make it look right. I have just learned HTML and CSS this past year so I've been spoiled to start with basically CSS3 and HTML5, and I can do some really cool stuff super fast. I'm no IE6 master and I don't have years of experience with IE. So I thought it'd take a little time to figure out all the hacks to IE6/7 discovered and just implement them. But it's way harder than that (or maybe just way too much work). I'd have to either completely rebuild my design using "Internet Explorer 'Principles'", or cut out a lot of the neat things I could do using more recent technologies. For a million and one other reasons, everyone who builds things online seems to think IE should die. My question is, why can't businesses upgrade their browsers? When I work with businesses, they almost always resist the first time I ask, but 5 seconds later I'll show them what it looks like on my computer and talk about how great the latest stuff is (how much more secure later browser are, all the famous IE security cases, how much smoother and faster they new browsers are, how the IE team has basically missed the boat entirely, how much smoother business processes run, etc.), and they get excited! And within a few seconds they're up and running with Chrome or something. So can businesses not upgrade for some reasons? What are the reasons a business cannot upgrade? The main reason I think of is because they have an old version of windows. But a) wasn't there a legal case against this? and b) somebody must have figured out how to install Chrome or Firefox on ancient versions of Windows by now.

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  • In the meantime, to be or not to be ... productive!

    - by Jan Kuboschek
    I just moved back to Europe from the US after living there for 7 years. Apart from major adjustment issues, I'm currently looking for a job over here. I'm mainly interested in (IT) Consulting and, since these jobs typically require programming knowledge, such as Java, I'm trying to think of something productive to write (perhaps to demo my skills) while I'm waiting for my interviews (starting in two weeks. Folks here are a bit slower than in the US apparently...). I graduated from college about a year and a half ago and have a 4 year degree in international management/economics and about 3/4 of a 2 year degree in computer science finished. I've written my fair share of web software over the years, but nothing concrete that I could show, especially not in Java. Now, I've never had the problem of not having any idea what to write. Basic games I could write, but I'm not sure how well that'll come over when I walk into my interview and say "hey, I was bored. Take a look at my multiplayer space invaders game! Wanna try beating me??". Any thoughts? I browsed SourceForge the other day to find a nice little project to contribute to, but decided that I don't want to commit to someone else's project at this time. Any ideas, perhaps from someone who has been, or currently is, in a similar position would be much appreciated. Oh, and lastly: Instead of developing a program or two to demonstrate my skills, I could spend my time brushing up on UML and Perl. Any suggestions regarding that? Writing a demo vs. learning something new?

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  • PHP transfer files from server to server in LAN

    - by cheapez
    So, I have 5-6 pages of requirements. I'm trying to build this application in PHP based on the requirements. I want to transfer files from one server to the other server in LAN, and then send a shell command to the other server to find out if the file has been transferred successfully. In php, I can transfer files using FTP, and send shell commands using SSH. Using the methods above, I will need to open connection to the server first, but I don't know the ftp server name, domain name, ip address, or anything like that. I only know the the server ID (I'm not sure what this ID is, but I guess it is like the computer's name). An example of the server ID is: "c23bap234" How do I open a connection with just that server ID? These servers are in the same building, have LAN connection, don't have connection to the outside world. These machines have PHP, Apache, ... installed. If my post doesn't make sense to you, it's because I'm a learner. I hope someone can help me on this. Thanks in advance.

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  • How do software projects go over budget and under-deliver?

    - by Carlos
    I've come across this story quite a few times here in the UK: NHS Computer System Summary: We're spunking £12 Billion on some health software with barely anything working. I was sitting the office discussing this with my colleagues, and we had a little think about. From what I can see, all the NHS needs is a database + middle tier of drugs/hospitals/patients/prescriptions objects, and various GUIs for doctors and nurses to look at. You'd also need to think about security and scalability. And you'd need to sit around a hospital/pharmacy/GPs office for a bit to figure out what they need. But, all told, I'd say I could knock together something with that kind of structure in a couple of days, and maybe throw in a month or two to make it work in scale. If I had a few million quid, I could probably hire some really excellent designers to make a maintainable codebase, and also buy appropriate hardware to run the system on. I hate to trivialize something that seems to have caused to much trouble, but to me it looks like just a big distributed CRUD + UI system. So how on earth did this project bloat to £12B without producing much useful software? As I don't think the software sounds so complicated, I can only imagine that something about how it was organised caused this mess. Is it outsourcing that's the problem? Is it not getting the software designers to understand the medical business that caused it? What are your experiences with projects gone over budget, under delivered? What are best practices for large projects? Have you ever worked on such a project?

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  • Reading input files in FORTRAN

    - by lollygagger
    Purpose: Create a program that takes two separate files, opens and reads them, assigns their contents to arrays, do some math with those arrays, create a new array with product numbers, print to a new file. Simple enough right? My input files have comment characters at the beginning. One trouble is, they are '#' which are comment characters for most plotting programs, but not FORTRAN. What is a simple way to tell the computer not to look at these characters? Since I have no previous FORTRAN experience, I am plowing through this with two test files. Here is what I have so far: PROGRAM gain IMPLICIT NONE REAL, DIMENSION (1:4, 1:8) :: X, Y, Z OPEN(1, FILE='test.out', & STATUS='OLD', ACTION='READ') ! opens the first file READ(1,*), X OPEN(2, FILE='test2.out', & STATUS='OLD', ACTION='READ') ! opens the second file READ(2,*), Y PRINT*, X, Y Z = X*Y ! PRINT*, Z OPEN(3, FILE='test3.out', STATUS='NEW', ACTION='WRITE') !creates a new file WRITE(3,*), Z CLOSE(1) CLOSE(2) CLOSE(3) END PROGRAM PS. Please do not overwhelm me with a bunch of code monkey gobblety gook. I am a total programming novice. I do not understand all the lingo, that is why I came here instead of searching for help in existing websites. Thanks.

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  • Windows Service Start-Up Error 1069

    - by Gavin
    Hello, I am installing a new windows service coded in C# on a server. I installed the service fine on the server, but once i manually start up the service on a server, with the same login credentials that our other services use, i get the fatal error message notification: "Could not start the %service name% on Local Computer. Error 1069: The Service did not start due to a logon failure." I looked in the event log and i got a 7038 and 7000 event id error in that order. 7038 event id message: "The %service name% service was unable to log on as %login% with the currently configured password due to the following error: Logon failure: unknown user name or bad password. To ensure that the service is configured properly, use the Services snap-in in Microsoft Management Console (MMC)." 7000 event id message: "The %service name% service failed to start due to the following error: The service did not start due to a logon failure. " I have other services that are using the same exact login account and they work fine. Is there something simple I could be missing? Thanks

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  • visual studio attaching to a process in debug mode

    - by user1612986
    i have a strange problem. the dll that i built (lets call it my.dll) in c++ visual studio 2010 uses a third party library (say tp.lib) which in turn calls a third party dll (say tp.dll). for debugging prupose i have in configurationProperties-debugging-command: Excel.exe and configurationProperties-debugging-commandArguments: "$(TargetPath)" in my computer i also set PATH variable to the directory where tp.dll resides now when i hit the F5 in visual studio excel opens up with my.dll and crashes giving me a "cannot open in dos mode" error. the reason this happens is tp.dll is not deployed when debug version of my.dll is deployed. when i open an instance of excel seperately and manually drop the debug version of my.dll then everything works fine and i can see all my functions that i wrote in my.dll the only issue is now i do not know how to debug becuase i do not know how to attach visual studio to the instance of excel i opened up seperately. my question is: 1 how can i attach visual studio to an already opened instance of Excel or 2 how can i hit F5 and still make Excel pick up the required tp.dll from the directory specified in the PATH variable before it starts to deploy my.dll. any of these two will allow my to step through the code for the purpose of debugging. thanks in advance.

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  • How to strengthen Mysql database server Security?

    - by i need help
    If we were to use server1 for all files (file server), server2 for mysql database (database server). In order for websites in server1 to access to the database in server2, isn't it needed to connect to to ip address of second (mysql server) ? In this case, is remote mysql connection. However, I seen from some people comment on the security issue. remote access to MySQL is not very secure. When your remote computer first connects to your MySQL database, the password is encrypted before being transmitted over the Internet. But after that, all data is passed as unencrypted "plain text". If someone was able to view your connection data (such as a "hacker" capturing data from an unencrypted WiFi connection you're using), that person would be able to view part or all of your database. So I just wondering ways to secure it? Allow remote mysql access from server1 by allowing the static ip adress allow remote access from server 1 by setting port allowed to connect to 3306 change 3306 to other port? Any advice?

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  • How to change database connection without compiling, using JBoss Seam?

    - by MLB
    Hi there: I am developing a web site in Eclipse using JBoss Seam 1.2. My site uses a database (named ALregcli) hosted in a MySQL server. That database has only one table named trazasfallos. The server I am using is local (localhost). When I deploy the site in an "X HOST", the MySQL server it is not in the same computer... the server is in an "Y HOST", so, the connection will not be stablished to the database. I was changing the Context.xml, but it didn't work. The only way it worked was changing the host to connect to in the Context.xml and "recompiling" all the project. Then, it generates the new version of the compiled class trazasfallos.class, and this is the file I have to overwrite for connecting to a new database server. The point is that I want to make the change without "recompiling" anything... Maybe there is a way to make only a "text change" and it will work (maybe in a .xml file)... but I don't know how to do it!! The question is: how to change the connection to the database without recompiling anything in the site?? I am sorry about my English, I am from Cuba.

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  • Effective optimization strategies on modern C++ compilers

    - by user168715
    I'm working on scientific code that is very performance-critical. An initial version of the code has been written and tested, and now, with profiler in hand, it's time to start shaving cycles from the hot spots. It's well-known that some optimizations, e.g. loop unrolling, are handled these days much more effectively by the compiler than by a programmer meddling by hand. Which techniques are still worthwhile? Obviously, I'll run everything I try through a profiler, but if there's conventional wisdom as to what tends to work and what doesn't, it would save me significant time. I know that optimization is very compiler- and architecture- dependent. I'm using Intel's C++ compiler targeting the Core 2 Duo, but I'm also interested in what works well for gcc, or for "any modern compiler." Here are some concrete ideas I'm considering: Is there any benefit to replacing STL containers/algorithms with hand-rolled ones? In particular, my program includes a very large priority queue (currently a std::priority_queue) whose manipulation is taking a lot of total time. Is this something worth looking into, or is the STL implementation already likely the fastest possible? Along similar lines, for std::vectors whose needed sizes are unknown but have a reasonably small upper bound, is it profitable to replace them with statically-allocated arrays? I've found that dynamic memory allocation is often a severe bottleneck, and that eliminating it can lead to significant speedups. As a consequence I'm interesting in the performance tradeoffs of returning large temporary data structures by value vs. returning by pointer vs. passing the result in by reference. Is there a way to reliably determine whether or not the compiler will use RVO for a given method (assuming the caller doesn't need to modify the result, of course)? How cache-aware do compilers tend to be? For example, is it worth looking into reordering nested loops? Given the scientific nature of the program, floating-point numbers are used everywhere. A significant bottleneck in my code used to be conversions from floating point to integers: the compiler would emit code to save the current rounding mode, change it, perform the conversion, then restore the old rounding mode --- even though nothing in the program ever changed the rounding mode! Disabling this behavior significantly sped up my code. Are there any similar floating-point-related gotchas I should be aware of? One consequence of C++ being compiled and linked separately is that the compiler is unable to do what would seem to be very simple optimizations, such as move method calls like strlen() out of the termination conditions of loop. Are there any optimization like this one that I should look out for because they can't be done by the compiler and must be done by hand? On the flip side, are there any techniques I should avoid because they are likely to interfere with the compiler's ability to automatically optimize code? Lastly, to nip certain kinds of answers in the bud: I understand that optimization has a cost in terms of complexity, reliability, and maintainability. For this particular application, increased performance is worth these costs. I understand that the best optimizations are often to improve the high-level algorithms, and this has already been done.

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  • How to make buttons in python/pygame?

    - by user1334014
    I'm making a game in pygame and on the first screen I want there to be buttons that you can press to (i) start the game, (ii) load a new screen with instructions, and (iii) exit the program. I've found this code online for button making, but I don't really understand it (I'm not that good at object oriented programming). If I could get some explanation as to what it's doing that would be great. Also, when I use it and try to open a file on my computer using the file path, I get the error sh: filepath :Permission denied, which I don't know how to solve. #load_image is used in most pygame programs for loading images def load_image(name, colorkey=None): fullname = os.path.join('data', name) try: image = pygame.image.load(fullname) except pygame.error, message: print 'Cannot load image:', fullname raise SystemExit, message image = image.convert() if colorkey is not None: if colorkey is -1: colorkey = image.get_at((0,0)) image.set_colorkey(colorkey, RLEACCEL) return image, image.get_rect() class Button(pygame.sprite.Sprite): """Class used to create a button, use setCords to set position of topleft corner. Method pressed() returns a boolean and should be called inside the input loop.""" def __init__(self): pygame.sprite.Sprite.__init__(self) self.image, self.rect = load_image('button.png', -1) def setCords(self,x,y): self.rect.topleft = x,y def pressed(self,mouse): if mouse[0] > self.rect.topleft[0]: if mouse[1] > self.rect.topleft[1]: if mouse[0] < self.rect.bottomright[0]: if mouse[1] < self.rect.bottomright[1]: return True else: return False else: return False else: return False else: return False def main(): button = Button() #Button class is created button.setCords(200,200) #Button is displayed at 200,200 while 1: for event in pygame.event.get(): if event.type == MOUSEBUTTONDOWN: mouse = pygame.mouse.get_pos() if button.pressed(mouse): #Button's pressed method is called print ('button hit') if __name__ == '__main__': main() Thank you to anyone who can help me.

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  • How i can fix the increasing order summation code?

    - by user2971559
    I want from the java to reads all numbers from the user as long as the number entered by user is bigger than the previous number. But i could write it for only positive numbers. How i can fix code below if all numbers included. If it is possible please write the solution for beginners because its my first year in computer science in college and I haven't learn a lot yet. import acm.program.*; public class IncreasingOrder extends ConsoleProgram { public void run() { int previousNumber = 0; int total = 0; int count = 0; while(true) { int n = readInt("Enter > "); if (n <= previousNumber) break; total += n; count++; previousNumber = n; } println("You have entered " + count + " numbers in increasing order."); println("Sum of these " + count + " numbers is " + total + "."); } }

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  • Drawing line graphics leads Flash to spiral out of control!

    - by drpepper
    Hi, I'm having problems with some AS3 code that simply draws on a Sprite's Graphics object. The drawing happens as part of a larger procedure called on every ENTER_FRAME event of the stage. Flash neither crashes nor returns an error. Instead, it starts running at 100% CPU and grabs all the memory that it can, until I kill the process manually or my computer buckles under the pressure when it gets up to around 2-3 GB. This will happen at a random time, and without any noticiple slowdown beforehand. WTF? Has anyone seen anything like this? PS: I used to do the drawing within a MOUSE_MOVE event handler, which brought this problem on even faster. PPS: I'm developing on Linux, but reproduced the same problem on Windows. UPDATE: You asked for some code, so here we are. The drawing function looks like this: public static function drawDashedLine(i_graphics : Graphics, i_from : Point, i_to : Point, i_on : Number, i_off : Number) : void { const vecLength : Number = Point.distance(i_from, i_to); i_graphics.moveTo(i_from.x, i_from.y); var dist : Number = 0; var lineIsOn : Boolean = true; while(dist < vecLength) { dist = Math.min(vecLength, dist + (lineIsOn ? i_on : i_off)); const p : Point = Point.interpolate(i_from, i_to, 1 - dist / vecLength); if(lineIsOn) i_graphics.lineTo(p.x, p.y); else i_graphics.moveTo(p.x, p.y); lineIsOn = !lineIsOn; } } and is called like this (m_graphicsLayer is a Sprite): m_graphicsLayer.graphics.clear(); if (m_destinationPoint) { m_graphicsLayer.graphics.lineStyle(2, m_fixedAim ? 0xff0000 : 0x333333, 1); drawDashedLine(m_graphicsLayer.graphics, m_initialPos, m_destinationPoint, 10, 10); }

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  • Best (functional?) programming language to learn coming from Mathematica

    - by Will Robertson
    As a mechanical engineering PhD student, I haven't had a great pedigree in programming as part of my “day job”. I started out in Matlab (having written some Hypercard and Applescript back in the day, and being introduced to Ada, of all things, in my 1st undergrad year), learned to program—if you can call it that—in (La)TeX; and finally discovered and fell for Mathematica. Now I'm interested in learning a "real" programming language that I can enjoy in the same sort of style as Mathematica, which tries to stress functional programming since it seems to map more nicely to how certain kinds of mathematics can be written algorithmically. So which functional language should I learn? I guess the obvious answer is “as many as possible”, but let's start out humble and give a single, well-considered option a good crack. I've heard good things about, say, Haskell and Scala, but I wonder if (given my non–computer science background) I'd be better off starting in more “grounded” territory and going with Ruby or Python (the latter having the big advantage of being used for Sage, which I'd also like to investigate…after my PhD). Well, I guess this is pretty subjective, so perhaps I could rephrase: would it be better to start looking at Haskell (say) straight after an ad-hoc education to functional programming in Mathematica, or will I get more out of learning Python (say) first? In reference to the question "what do I want to do with it?", I guess my answer is "fun, and learning more". I've got this list of languages that I'd like to look at, and I don't know how to trim them down. And I'd rather start with something a little higher-level than C simply so that I can be somewhat productive without having to re-invent many wheels for any code I'd like to write.

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  • Call 32-bit or 64-bit program from bootloader

    - by user1002358
    There seems to be quite a lot of identical information on the Internet about writing the following 3 bootloaders: Infinite loop jmp $ Print a single character Print "Hello World". This is fantastic, and I've gone through these 3 variations with very little trouble. I'd like to write some 32- or 64-bit code in C and compile it, and call that code from the bootloader... basically a bootloader that, for example, sets the computer up to run some simple numerical simulation. I'll start by listing primes, for example, and then maybe some input/output from the user to maybe compute a Fourier transform. I don't know. I haven't found any information on how to do this, but I can already foresee some problems before I even begin. First of all, compiling a C program compiles it into one of several different files, depending on the target. For Windows, it's a PE file. For Linux, it's a .out file. These files are both quite different. In my instance, the target isn't Windows or Linux, it's just whatever I have written in the bootloader. Secondly, where would the actual code reside? The bootloader is exactly 512 bytes, but the program I write in C will certainly compile to something much larger. It will need to sit on my (virtual) hard disk, probably in some sort of file system (which I haven't even defined!) and I will need to load the information from this file into memory before I can even think about executing it. But from my understanding, all this is many, many orders of magnitude more complex than a 12-line "Hello World" bootloader. So my question is: How do I call a large 32- or 64-bit program (written in C/C++) from my 16-bit bootloader.

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  • explain notifier.c from the Linux kernel

    - by apollon
    I'm seeking to fully understand the following code snippet from kernel/notifier.c. I have read and built simple link lists and think I get the construct from K&R's C programming. The second line below which begins with the 'int' appears to be two items together which is unclear. The first is the (*notifier_call) which I believe has independent but related significance with the second containing a 'notifier block' term. Can you explain how it works in detail? I understand that there is a function pointer and multiple subscribers possible. But I lack the way to tie these facts together, and could use a primer or key so I exactly understand how the code works. The third line looks to contain the linking structure, or recursive nature. Forgive my terms, and correct them as fit as I am a new student of computer science terminology. struct notifier_block { int (*notifier_call)(struct notifier_block *, unsigned long, void *); struct notifier_block *next; int priority; };

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  • How to have screen revert to BLACK between pages?

    - by user340667
    0 Hi - I tried out the Background Image Scaling script and with Cybr's update it works like magic. It SCALES the image perfectly. No distortion. BUT, my image isn't "computer friendly". I.e.: Not 1024 X 768 or even close to that. (Heck, my monitor has a wide screen, so it isn't 1024 X 768 either! Is anybody's anymore?) Anyhow, this creates a problem inasmuch as, unless I size the window from the bottom up it ends up with a white "stripe" beneath it. What I would REALLY like for it to do is have that white to be BLACK. My "usual" BG color/text etc. code is like: ""body bgcolor="#000000" text="#fcba1e" link="#0000ff" vlink="#800080" alink="#ff0000"" (Site won't let me add the arrows here.) I've tried inserting this in various places with no success. Any ideas for a workaround would surely be appreciated ! Thanks ! Bill

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  • expanding/collapsing div using jQuery

    - by Hristo
    I'm trying to expand and collapse a <div> by clicking some text inside the <div>. The behavior right now is very odd. For example, if I click the text after the <div> is expanded... the <div> will collapse and then expand again. Also, if I click somewhere inside the div after it is expanded, it will collapse again, and I think that is because I'm triggering the animation since the <div> being animated is inside the wrapper <div>. Here's the code: <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> <!-- Links --> <link rel="stylesheet" type="text/css" href="style.css" /> <!-- Scripts --> <script type="text/javascript" src="jQuery.js"></script> <script> // document script $(function(){ // login box event handler $('#login').click(function() { $('#loginBox').toggle( function() { $('.loginBox').animate({ height: '150px' }, '1000' ); $('#username').show(); $('#password').hide(); $('#placeHolder').show(); }, function() { $('.loginBox').animate({ height: '50px' }, '1000' ); $('#username').hide(); $('#password').hide(); $('#placeHolder').hide(); } ); }); // username field focus and blur event handlers $('#username').focus(function() { if($(this).hasClass('placeHolder')){ $(this).val(''); $(this).removeClass('placeHolder'); } }); $('#username').blur(function() { if($(this).val() == '') { $(this).val('Username'); $(this).addClass('placeHolder'); } }); // password field focus and blur event handlers $('#placeHolder').focus(function() { $(this).hide(); $('#password').show(); $('#password').focus(); $('#password').removeClass('placeHolder'); }); $('#password').blur(function() { if($(this).val() == '') { $('#placeHolder').show(); $(this).hide(); } }); }); </script> </head> <body> <div id="loginBox" class="loginBox"> <a id="login" class="login">Proceed to Login</a><br /> <div> <form> <input type="text" id="username" class="placeHolder" value="Username" /> <input type="password" id="password" class="placeHolder" value="" /> <input type="text" id="placeHolder" class="placeHolder" value="Password" /> </form> </div> </div> </body> </html> Any ideas? Thanks, Hristo

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  • Custom API requirement

    - by Jonathan.Peppers
    We are currently working on an API for an existing system. It basically wraps some web-requests as an easy-to-use library that 3rd party companies should be able to use with our product. As part of the API, there is an event mechanism where the server can call back to the client via a constantly-running socket connection. To minimize load on the server, we want to only have one connection per computer. Currently there is a socket open per process, and that could eventually cause load problems if you had multiple applications using the API. So my question is: if we want to deploy our API as a single standalone assembly, what is the best way to fix our problem? A couple options we thought of: Write an out of process COM object (don't know if that works in .Net) Include a second exe file that would be required for events, it would have to single-instance itself, and open a named pipe or something to communicate through multiple processes Extract this exe file from an embedded resource and execute it None of those really seem ideal. Any better ideas?

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  • ORDERBY "human" alphabetical order using SQL string manipulation

    - by supertrue
    I have a table of posts with titles that are in "human" alphabetical order but not in computer alphabetical order. These are in two flavors, numerical and alphabetical: Numerical: Figure 1.9, Figure 1.10, Figure 1.11... Alphabetical: Figure 1A ... Figure 1Z ... Figure 1AA If I orderby title, the result is that 1.10-1.19 come between 1.1 and 1.2, and 1AA-1AZ come between 1A and 1B. But this is not what I want; I want "human" alphabetical order, in which 1.10 comes after 1.9 and 1AA comes after 1Z. I am wondering if there's still a way in SQL to get the order that I want using string manipulation (or something else I haven't thought of). I am not an expert in SQL, so I don't know if this is possible, but if there were a way to do conditional replacement, then it seems I could impose the order I want by doing this: delete the period (which can be done with replace, right?) if the remaining figure number is more than three characters, add a 0 (zero) after the first character. This would seem to give me the outcome I want: 1.9 would become 109, which comes before 110; 1Z would become 10Z, which comes before 1AA. But can it be done in SQL? If so, what would the syntax be? Note that I don't want to modify the data itself—just to output the results of the query in the order described. This is in the context of a Wordpress installation, but I think the question is more suitably an SQL question because various things (such as pagination) depend on the ordering happening at the MySQL query stage, rather than in PHP.

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  • Scalable way to store files on server (PHP)?

    - by Nathaniel Bennett
    I'm creating my first web application - a really simplistic online text editor. What I need to do is find the best way to store text based files - a lot of them. These text files can be past 10,000 words in size (text words not computer words.) in essence I want the text documents to be limitless in size. I was thinking about storing the text files in my MySQL database - but thought there was a better way. Instead I'm planing on storing the text files in XML based format in a directory on my server. The rows in the database define the name of the xml based text file and the user who created the text along with basic metadata. An ID is generated using a V4 GUID generator , which gives the text an id and stores the text in the "/store" directory on my server. The text definitions in my server contain this id, and the android app I'm developing gets the contents of the text file by retrieving the text definition and then downloading the text to the local device using the GUID in the text definition. I just think this is a botch job? how can I improve this system? There has been cases of GUID colliding. I don't want this to happen. A "slim" possibility isn't good enough - I need to make sure there is absolutely no chance in a GUID collision. I was planning on checking the database for texts that have the same id before storing the text with a particular id - I however believe with over 20,000 pieces of text in my database this would take an long time and produce unneeded stress on the server. How can I make GUID safe? What happens when a GUID collides? The server backend is going to be written in PHP.

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