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• Any guidelines for handling the Headset and Bluetooth AVRC transport controls in Android 2.2

  - by StefanK

  I am trying to figure out what is the correct (new) approach for handling the Intent.ACTION_MEDIA_BUTTON in Froyo. In pre 2.2 days we had to register a BroadcastReceiver (either permanently or at run-time) and the Media Button events would arrive, as long as no other application intercepts them and aborts the broadcast. Froyo seems to still somewhat support that model (at least for the wired headset), but it also introduces the registerMediaButtonEventReceiver, and unregisterMediaButtonEventReceiver methods that seem to control the "transport focus" between applications. During my experiments, using registerMediaButtonEventReceiver does cause both the bluetooth and the wired headset button presses to be routed to the application's broadcast receiver (the app gets the "transport focus"), but it looks like any change in the audio routing (for example unplugging the headset) shits the focus back to the default media player. What is the logic behind the implementation in Android 2.2? What is correct way to handle transport controls? Do we have to detect the change in the audio routing and try to re-gain the focus? This is an issue that any 3rd party media player on the Android platform has to deal with, so I hope that somebody (probably a Google Engineer) can provide some guidelines that we can all follow. Having a standard approach may make headset button controls a bit more predictable for the end users. Stefan

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• jQuery draggable removing without changing position of other elements

  - by Yurish

  Hi! I am building a page layout configuration system on jQuery. So everyone, who is using my website can make it personal by moving elements on webpage. But, I have a problem. Every element on my page is a draggable div with option to be removed from page if necessary. When user wants to remove an element, he clicks on inner div and the following function is called: <script language="javascript"> $(function() { $('.close').click(function(){ $(this).parent().hide(); }); }); </script> <div class="main"><div class="close"></div></div> When user wants to add an element on page, he clicks on link and followinf function is called: function addNewWidget(page_name, size){ var page = $('#'+page_name); var closeDiv = $(document.createElement("div")).attr("class", "close").html('X'); closeDiv.click(function(){ $(this).parent().hide(); }); var div = $(document.createElement("div")) div.attr("class", "drag"); div.appendTo(page); closeDiv.appendTo(div); div.draggable({ containment: "#page", scroll: false, grid: [200, 200] }); div.css("top:0; left:0"); div.addClass(size); div.addClass('widget'); } Everything works fine, but when element is removed, other elements, which were on page are moving up. It is because of element positioning in the code. These divs in the code are before div, which was removed, and their absolute top is changed by -heghtOfRemovedElement Is there any way to prevent other elements from moving up?

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• initialise a var in scala

  - by user unknown

  I have a class where I like to initialize my var by reading a configfile, which produces intermediate objects/vals, which I would like to group and hide in a method. Here is the bare minimum of the problem - I call the ctor with a param i, in reality a File to parse, and the init-method generates the String s, in reality more complicated than here, with a lot of intermediate objects being created: class Foo (val i: Int) { var s : String; def init () { s = "" + i } init () } This will produce the error: class Foo needs to be abstract, since variable s is not defined. In this example it is easy to solve by setting the String to "": var s = "";, but in reality the object is more complex than String, without an apropriate Null-implementation. I know, I can use an Option, which works for more complicated things than String too: var s : Option [String] = None def init () { s = Some ("" + i) } or I can dispense with my methodcall. Using an Option will force me to write Some over and over again, without much benefit, since there is no need for a None else than to initialize it that way I thought I could. Is there another way to achieve my goal?

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• How to mock/stub a directory of files and their contents using RSpec?

  - by John Topley

  A while ago I asked "How to test obtaining a list of files within a directory using RSpec?" and although I got a couple of useful answers, I'm still stuck, hence a new question with some more detail about what I'm trying to do. I'm writing my first RubyGem. It has a module that contains a class method that returns an array containing a list of non-hidden files within a specified directory. Like this: files = Foo.bar :directory => './public' The array also contains an element that represents metadata about the files. This is actually a hash of hashes generated from the contents of the files, the idea being that changing even a single file changes the hash. I've written my pending RSpec examples, but I really have no idea how to implement them: it "should compute a hash of the files within the specified directory" it "shouldn't include hidden files or directories within the specified directory" it "should compute a different hash if the content of a file changes" I really don't want to have the tests dependent on real files acting as fixtures. How can I mock or stub the files and their contents? The gem implementation will use Find.find, but as one of the answers to my other question said, I don't need to test the library. I really have no idea how to write these specs, so any help much appreciated!

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• Proper structure for dependency injection (using Guice)

  - by David B.

  I would like some suggestions and feedback on the best way to structure dependency injection for a system with the structure described below. I'm using Guice and thus would prefer solutions centered around it's annotation-based declarations, not XML-heavy Spring-style configuration. Consider a set of similar objects, Ball, Box, and Tube, each dependent on a Logger, supplied via the constructor. (This might not be important, but all four classes happen to be singletons --- of the application, not Gang-of-Four, variety.) A ToyChest class is responsible for creating and managing the three shape objects. ToyChest itself is not dependent on Logger, aside from creating the shape objects which are. The ToyChest class is instantiated as an application singleton in a Main class. I'm confused about the best way to construct the shapes in ToyChest. I either (1) need access to a Guice Injector instance already attached to a Module binding Logger to an implementation or (2) need to create a new Injector attached to the right Module. (1) is accomplished by adding an @Inject Injector injectorfield to ToyChest, but this feels weird because ToyChest doesn't actually have any direct dependencies --- only those of the children it instantiates. For (2), I'm not sure how to pass in the appropriate Module. Am I on the right track? Is there a better way to structure this? The answers to this question mention passing in a Provider instead of using the Injector directly, but I'm not sure how that is supposed to work. EDIT: Perhaps a more simple question is: when using Guice, where is the proper place to construct the shapes objects? ToyChest will do some configuration with them, but I suppose they could be constructed elsewhere. ToyChest (as the container managing them), and not Main, just seems to me like the appropriate place to construct them.

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• how to emulate thread local storage at user space in C++ ?

  - by vprajan

  I am working on a mobile platform over Nucleus RTOS. It uses Nucleus Threading system but it doesn't have support for explicit thread local storage i.e, TlsAlloc, TlsSetValue, TlsGetValue, TlsFree APIs. The platform doesn't have user space pthreads as well. I found that __thread storage modifier is present in most of the C++ compilers. But i don't know how to make it work for my kind of usage. How does __thread keyword can be mapped with explicit thread local storage? I read many articles but nothing is so clear for giving me the following basic information will __thread variable different for each thread ? How to write to that and read from it ? does each thread has exactly one copy of the variable ? following is the pthread based implementation: pthread_key_t m_key; struct Data : Noncopyable { Data(T* value, void* owner) : value(value), owner(owner) {} int* value; }; inline ThreadSpecific() { int error = pthread_key_create(&m_key, destroy); if (error) CRASH(); } inline ~ThreadSpecific() { pthread_key_delete(m_key); // Does not invoke destructor functions. } inline T* get() { Data* data = static_cast<Data*>(pthread_getspecific(m_key)); return data ? data->value : 0; } inline void set(T* ptr) { ASSERT(!get()); pthread_setspecific(m_key, new Data(ptr, this)); } How to make the above code use __thread way to set & get specific value ? where/when does the create & delete happen? If this is not possible, how to write custom pthread_setspecific, pthread_getspecific kind of APIs. I tried using a C++ global map and index it uniquely for each thread and retrieved data from it. But it didn't work well.

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• How to resize a UISwitch?

  - by mshsayem

  I have made a custom UISwitch (from this post). But the problem is, my custom texts are a bit long. Is there any way to resize the switch? [I tried setBounds, did not work] Edit: Here is the code I used: @interface CustomUISwitch : UISwitch - (void) setLeftLabelText: (NSString *) labelText; - (void) setRightLabelText: (NSString *) labelText; @end @implementation CustomUISwitch - (UIView *) slider { return [[self subviews] lastObject]; } - (UIView *) textHolder { return [[[self slider] subviews] objectAtIndex:2]; } - (UILabel *) leftLabel { return [[[self textHolder] subviews] objectAtIndex:0]; } - (UILabel *) rightLabel { return [[[self textHolder] subviews] objectAtIndex:1]; } - (void) setLeftLabelText: (NSString *) labelText { [[self leftLabel] setText:labelText]; } - (void) setRightLabelText: (NSString *) labelText { [[self rightLabel] setText:labelText]; } @end mySwitch = [[CustomUISwitch alloc] initWithFrame:CGRectZero]; //Tried these, but did not work //CGRect aFrame = mySwitch.frame; //aFrame.size.width = 200; //aFrame.size.height = 100; //mySwitch.frame = aFrame; [mySwitch setLeftLabelText: @"longValue1"]; [mySwitch setRightLabelText: @"longValue2"];

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• C++ Beginner - Trouble using structs and constants!

  - by Francisco P.

  Hello everyone! I am currently working on a simple Scrabble implementation for a college project. I can't get a part of it to work, though! Check this out: My board.h: http://pastebin.com/J9t8VvvB The subroutine where the error lies: //Following snippet contained in board.cpp //I believe the function is self-explanatory... //Pos is a struct containing a char, y, a int, x and an orientation, o, which is not //used in this particular case void Board::showBoard() { Pos temp; temp.o = 0; for (temp.y = 'A'; temp.y < (65 + TOTAL_COLUMNS); ++temp.y) { for (temp.x = 1; temp-x < (1 + TOTAL_ROWS); ++temp.x) { cout << _matrix[temp].getContents(); } cout << endl; } } The errors returned on compile time: http://pastebin.com/bZv7fggq How come the error states that I am trying to compare two Pos when I am comparing chars and ints? I also really can't place these other errors... Thanks for your time!

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• How to implement a grapher in C#

  - by iansinke

  So I'm writing a graphing calculator. So far I have a semi-functional grapher, however, I'm having a hard time getting a good balance between accurate graphs and smooth looking curves. The current implementation (semi-pseudo-code) looks something like this: for (float i = GraphXMin; i <= GraphXMax; i++) { PointF P = new PointF(i, EvaluateFunction(Function, i) ListOfPoints.Add(P) } Graphics.DrawCurve(ListOfPoints) The problem with this is since it only adds a point at every integer value, graphs end up distorted when their turning points don't fall on integers (e.g. sin(x)^2). I tried incrementing i by something smaller (like 0.1), which works, but the graph looks very rough. I am using C# and GDI+. I have SmoothingMethod set to AntiAlias, so that's not the problem, as you can see from the first graph. Is there some sort of issue with drawing curves with a lot of points? Should the points perhaps be positioned exactly on pixels? I'm sure some of you have worked on something very similar before, so any suggestions? While you're at it, do you have any suggestions for graphing functions with asymptotes? e.g. 1/x^2 P.S. I'm not looking for a library that does all this - I want to write it myself.

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• How to have table span the entire height?

  - by Yogendra

  Hi All, I have a html table and I am trying to have it span the entire page height. For some reason I am not able to get this to work. I have set the html, body and table height to be 100%, but the table still does not occupy the entire 100%. Heres the code. It is very basic because I am just trying to have the table occupy the entire height. <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebApplication1.WebForm1" %> <style type="text/css"> body,html { margin:0; padding:0; height:100%; } </style> <table border="2" cellpadding="0" cellspacing="0" style="height:100%; width:100%" > <tr> <td>ABCD</td> </tr> </table> </form> I tried for couple of hours and I could not get it to work. Any help is really appreciated.

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• Attempt to create nested for loops generating missing arguments error

  - by JerryK

  Am attempting to teach myself to program using Tcl. (I want to become more familiar with the language to understand someone else's code - SCID chess) The task i've set myself to motivate my learing of Tcl is to solve the 8 queens problem. My approach to creating a program is to sucessively 'prototype' a solution. So. I'm up to nesting a for loop holding the q pos on row 2 inside the for loop holding the q pos on row 1 Here is my code set allowd 1 set notallowd 0 for {set r1p 1} {$r1p <= 8} {incr r1p } { puts "1st row q placed at $r1p" ;# re-initialize r2 'free for q placemnt' array after every change of r1 q pos: for {set i 1 } {$i <= 8} {incr i} { set r2($i) $allowd } for { set r2($r1p) $notallowd ; set r2([eval $r1p-1]) $notallowd ; set r2([eval $r1p+1]) $notallowd ; set r2p 1} {$r2p <= 8} { incr r2p ;# end of 'next' arg of r2 forloop } ;# commnd arg of r2 forloop placed below: {puts "2nd row q placed at $r2p" } } My problem is that when i run the code the interpreter is aborting with the fatal error: "wrong #args should be for start test next command. I've gone over my code a few times and can't see that i've missed any of the for loop arguments.

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• move jQuery code to a function

  - by GSTAR

  I have the following jQuery code: $('.show-additional-link').click(function(){ $(this).parent().next().slideDown(); $(this).hide(); return false; }); HTML: <div class="row"> <label for="native_language">Select</label> <select name="native_language" id="native_language"> <option value="">Any</option> <option value="1">English</option> </select> <a class="show-additional-link" href="#">Select Additional Languages</a> </div> <div id="additional-languages" style="display: none;"> <a class="hide-additional-link" href="#">[hide]</a> <div class="row"> <!-- additional language checkboxes --> </div> </div> I would like to move the contents of my jQuery code (within the 'click' function) in to a separate function, as I will need to call it again on page load (after the form is submitted, so that the DIV is shown again automatically). I'm having trouble with this - can anyone help?

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• How do you unit test new code that uses a bunch of classes that cannot be instantiated in a test har

  - by trendl

  I'm writing a messaging layer that should handle communication with a third party API. The API has a bunch of classes that cannot be easily (if at all) instantiated in a test harness. I decided to wrap each class that I need in my unit tests with an adapter/wrapper and expose the members I need through this adapter class. Often I need to expose the wrapped type as well which I do by exposing it as an object. I have also provided an interface for for each or the adapter classes to be able to use them with a mocking framework. This way I can substitute the classes in test for whatever I need. The downside is that I have a bunch of adapter classes that so far server no other reason but testing. For me this is a good reason by itself but others may find this not enough. Possibly, when I write an implementation for another third party vendor's API, I may be able to reuse much of my code and only provide the adapters specific to the vendor's API. However, this is a bit of a long shot and I'm not actually sure it will work. What do you think? Is this approach viable or am I writing unnecessary code that serves no real purpose? Let me say that I do want to write unit tests for my messaging layer and I do now know how to do it otherwise.

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• Is it getting to be time for C# to support compile-time macros?

  - by Robert Rossney

  Thus far, Microsoft's C# team has resisted adding formal compile-time macro capabilities to the language. There are aspects of programming with WPF that seem (to me, at least) to be creating some compelling use cases for macros. Dependency properties, for instance. It would be so nice to just be able to do something like this: [DependencyProperty] public string Foo { get; set; } and have the body of the Foo property and the static FooProperty property be generated automatically at compile time. Or, for another example an attribute like this: [NotifyPropertyChanged] public string Foo { get; set; } that would make the currently-nonexistent preprocessor produce this: private string _Foo; public string Foo { get { return _Foo; } set { _Foo = value; OnPropertyChanged("Foo"); } } You can implement change notification with PostSharp, and really, maybe PostSharp is a better answer to the question. I really don't know. Assuming that you've thought about this more than I have, which if you've thought about it at all you probably have, what do you think? (This is clearly a community wiki question and I've marked it accordingly.)

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• Computing, storing, and retrieving values to and from an N-Dimensional matrix

  - by Adam S

  This question is probably quite different from what you are used to reading here - I hope it can provide a fun challenge. Essentially I have an algorithm that uses 5(or more) variables to compute a single value, called outcome. Now I have to implement this algorithm on an embedded device which has no memory limitations, but has very harsh processing constraints. Because of this, I would like to run a calculation engine which computes outcome for, say, 20 different values of each variable and stores this information in a file. You may think of this as a 5(or more)-dimensional matrix or 5(or more)-dimensional array, each dimension being 20 entries long. In any modern language, filling this array is as simple as having 5(or more) nested for loops. The tricky part is that I need to dump these values into a file that can then be placed onto the embedded device so that the device can use it as a lookup table. The questions now, are: What format(s) might be acceptable for storing the data? What programs (MATLAB, C#, etc) might be best suited to compute the data? C# must be used to import the data on the device - is this possible given your answer to #1?

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• Immutability and shared references - how to reconcile?

  - by davetron5000

  Consider this simplified application domain: Criminal Investigative database Person is anyone involved in an investigation Report is a bit of info that is part of an investigation A Report references a primary Person (the subject of an investigation) A Report has accomplices who are secondarily related (and could certainly be primary in other investigations or reports These classes have ids that are used to store them in a database, since their info can change over time (e.g. we might find new aliases for a person, or add persons of interest to a report) If these are stored in some sort of database and I wish to use immutable objects, there seems to be an issue regarding state and referencing. Supposing that I change some meta-data about a Person. Since my Person objects immutable, I might have some code like: class Person( val id:UUID, val aliases:List[String], val reports:List[Report]) { def addAlias(name:String) = new Person(id,name :: aliases,reports) } So that my Person with a new alias becomes a new object, also immutable. If a Report refers to that person, but the alias was changed elsewhere in the system, my Report now refers to the "old" person, i.e. the person without the new alias. Similarly, I might have: class Report(val id:UUID, val content:String) { /** Adding more info to our report */ def updateContent(newContent:String) = new Report(id,newContent) } Since these objects don't know who refers to them, it's not clear to me how to let all the "referrers" know that there is a new object available representing the most recent state. This could be done by having all objects "refresh" from a central data store and all operations that create new, updated, objects store to the central data store, but this feels like a cheesy reimplementation of the underlying language's referencing. i.e. it would be more clear to just make these "secondary storable objects" mutable. So, if I add an alias to a Person, all referrers see the new value without doing anything. How is this dealt with when we want to avoid mutability, or is this a case where immutability is not helpful?

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• Organising files and classes in XCode (iPhone application)

  - by pulegium

  It's a generic question and really a newbie one too, so bear with me... I'm playing with some iPhone development, and trying to create a simple "flip type" application. Nothing sophisticated, let's say on the flip side is a short application summary, bit like 'help' and on the main screen is a simple board game, let's say tic-tac-toe or similar. Now, XCode has generated me 'Main View', 'Flipside View' and 'Application Delegate' folders, with default template files in them. Now the question is where do I create appropriate 'MVC' classes? Let's say (V)iew classes are going to be the ones that have been automatically created. So the Flipside view class is responsible for generating text/images etc on the 'help' view. 'Main View' class is what draws the items on the table and updates the counters, etc. Where should I place the 'controller' class? And also, should it only be dealing with proxying only to the model? According to this the controller method is called from the view and manipulates the method classes. Similarly, the results from model are passed back to the view class by the controller issuing the calls to appropriate view methods. Similarly, where does the model class go? or should I just create a new folder for each, controller and model class files? What I'm after is the best practices, or just a short description how people normally structure their applications. I know it's very specific and also undefined... I came from Django background, so the way stuff is organised there is slightly different. Hope this makes sense, sorry if it's all bit vague, but I have to start somewhere :) And yes I've read quite few docs on the apple developer site, but trouble is that the documents are either going into too much detail about the language/framework/etc and the examples are way too simplistic. Actually, this leads me to the final question, has anyone know any good example of relatively complete application tutorial which I could use as a reference in organising my files?...

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• Flowcharting functional programming languages

  - by Sadface

  Flowcharting. This ancient old practice that's been in use for over 1000 years now, being forced upon us poor students, without any usefulness (or so do I think). It might work well with imperative, sequentially running languages, but what about my beloved functional programming? Sadly, I'm forced to create a flow chart for my programm (that is written in Haskell). I imagine it being easy for something like this: main :: IO () main = do someInput <- getLine let upped = map toUpper someInput putStrLn upped Which is just 3 sequenced steps, fetching data, uppercasing it, outputting it. Things look worse this time: main :: IO () main = do someInput <- fmap toUpper getLine putStrLn someInput Or like this: main :: IO () main = interact (map toUpper) Okay, that was IO, you can handle that like an imperative language. What about pure functions? An actual example: onlyMatching :: String -> [FilePath] -> [FilePath] onlyMatching ext = filter f where f name = lower ('.' : ext) == (lower . takeExtension $ name) lower = map toLower How would you flowchart that last one?

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• Regarding Div Display

  - by user71723

  Hi to all, When i click on button,one div is showing..whenever i click on the body,that div will be hide. How can we achieve this functionality .. i write one code is as below. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> <title>Untitled Document</title> <script language="javascript"> function HideSubMenus(e) { var targ; if (!e) var e = window.event; if (e.target) targ = e.target; else if (e.srcElement) targ = e.srcElement; if (targ.nodeType == 3) // defeat Safari bug targ = targ.parentNode; for (var i=0; i!=5; i++) { if (!targ) { break; } else if (targ.className=="divclass") { return; } targ = targ.parentNode; } if(document.getElementById("showdivid")) { document.getElementById("showdivid").style.display=''; } } </script> </head> <body onclick="HideSubMenus(event);"> <input type="button" name="button" value="Click ME" onclick="document.getElementById('showdivid').style.display='';" /> <div id="showdivid" class="divclass" style="display:none;"> TeSt DIV </div> </body> </html> regards raj

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• java array pass by reference does not work?

  - by stdnoit

  guys i thought almost all language including java pass array into function as reference (modifiable) but somehow it does not work here. and the testArray is still 1,2,3 with size of 3 strange enough, when if i change result[i] = 2 to a[1] =2; it work . it did pass by reference what is wrong with this code? at the end, i had a = result; (which update the a). did result get removed from stack. that is why a still get to the original a ? i am confused. thanks class Test { public static void main(String[] args) { int[] testArray = {1,2,3}; equalize(testArray, 6); System.out.println("test Array size :" + testArray.length); for(int i = 0; i < testArray.length; i++) System.out.println(testArray[i]); } public static void equalize(int[] a, int biggerSize) { if(a.length > biggerSize) throw new Error("Array size bigger than biggerSize"); int[] result = new int[biggerSize]; // System.arraycopy(a, 0, result, 0, a.length); // int array default value should be 0 for(int i = 0; i < biggerSize; i++) result[i] = 2; a = result; } }

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• Scroll table upwards or downwards using up and down button

  - by Psinyee

  I want to create a banner scrolling function for my homepage. I am not too sure of which programming language to use here. I want to code something similar to: http://www.squidfaceandthemeddler.com/. But I want the footer to remain at the same position while the user scroll the table. Is it possible to get that result? I have create a simple tables and 2 images for the user to click on here is my code for the tables: <div id="banner" style="height:750px; width:600px; overflow:scroll;" > <table width="750px" height="600px"> <tr> <td><a href="sale_1.php"><img src="banner1.png"/></a></td> </tr> </table> <table width="750px" height="600px"> <tr> <td><a href="sale_2.php"><img src="banner2.png"/></a></td> </tr> </table> <table width="750px" height="600px"> <tr> <td><a href="sale_3.php"><img src="banner3.png"/></a></td> </tr> </table> </div> and this is the upwards and downwards button for the scrolling: <table width="750px" height="30px"> <tr> <td align="right"><img src="images/up_arrow.png"/><img src="images/down_arrow.png"/></td> </tr> </table>

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• Which Perl moudle can handle variety of date formats with unicode characters ?

  - by ram

  My requirement is parsing xml files which contains wide varieties of timestamps based on the locales at which they are written. They may contain Unicode characters in case of Chinese or Korean locales. I have to parse these timestamps and put then in a standard format something like 2009-11-26 12:40:54 to put them in a oracle database. Sometimes I may not even know the locale and yet I have to parse the timestamps. I am looking for a module that automatically detects the timestamp format (including unicode characters for am and pm in their local language) and converts in to epoch time so that I can convert it back to what ever way I like to. I have gone through similar questions in this forum. Few suggested DateFormat module, and Date::Parse module. The perl distribution I am using is 5.10 so Date::Manip doesn't come as a core module. As I am supposed to use just the basic core modules and few CPAN modules(on request I cannot ask for all), I request you to kindly suggest me a good module that suffices all my requirements. Thanks in advance

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• A generic C++ library that provides QtConcurrent functionality?

  - by Lucas

  QtConcurrent is awesome. I'll let the Qt docs speak for themselves: QtConcurrent includes functional programming style APIs for parallel list processing, including a MapReduce and FilterReduce implementation for shared-memory (non-distributed) systems, and classes for managing asynchronous computations in GUI applications. For instance, you give QtConcurrent::map() an iterable sequence and a function that accepts items of the type stored in the sequence, and that function is applied to all the items in the collection. This is done in a multi-threaded manner, with a thread pool equal to the number of logical CPU's on the system. There are plenty of other function in QtConcurrent, like filter(), filteredReduced() etc. The standard CompSci map/reduce functions and the like. I'm totally in love with this, but I'm starting work on an OSS project that will not be using the Qt framework. It's a library, and I don't want to force others to depend on such a large framework like Qt. I'm trying to keep external dependencies to a minimum (it's the decent thing to do). I'm looking for a generic C++ framework that provides me with the same/similar high-level primitives that QtConcurrent does. AFAIK boost has nothing like this (I may be wrong though). boost::thread is very low-level compared to what I'm looking for. I know C# has something very similar with their Parallel Extensions so I know this isn't a Qt-only idea. What do you suggest I use?

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• How to obtain value of auto_increment field in Access linked to MySQL?

  - by Cruachan

  I'm trying to modify and existing Access application to use MySQL as a database via ODBC with the minimal amount of recoding. The current code will often insert a new record using DAO then obtain the ID by using LastModified. This doesn't work with MySQL. Instead I'm trying to use the approach using SELECT * FROM tbl_name WHERE auto_col IS NULL Suggested for Access in the MySQL documentation. However if I set up a sample table consisting of just an id and text data field and execute this CurrentDb.Execute ("INSERT INTO tbl_scratch (DATA) VALUES ('X')") Set rst = CurrentDb.OpenRecordset("SELECT id FROM tbl_scratch WHERE id IS NULL") myid = rst!id Id is returned as null. However if I execute INSERT INTO tbl_scratch (DATA) VALUES ('X'); SELECT id FROM tbl_scratch WHERE id IS NULL; using a direct MySQL editor then id is returned correctly, so my database and approach is fine but my implementation inside Access must be incorrect. Frustratingly the MySQL documentation gives the SQL statement to retrieve the id as an example that works in Access (as it states LAST_INSERT_ID() doesn't) but gives no further details. How might I fix this?

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• EF 4.0 Guid or Int as A primary Key

  - by bigb

  I am Implementing custom ASPNetMembership using EF 4.0 Is there any reason why i should use Guid as a primary key in User tables? As far as i know Int as a PK on SQL Server more performanced than strings. And Int is easier to iterate. Also, for security purpose if i need to pass this it id somewhere in url i may encrypt it somehow and pass it like a strings with no probs. But if i want to use auto generated Guid on SQL Server side using EF 4.0 i need to do this trick http://leedumond.com/blog/using-a-guid-as-an-entitykey-in-entity-framework-4/ I can't see any cases why i should use Guid as PK, may be only one if system going to have millions ans millions users, but also, theoretically, Guid could be duplicated sometime isn't so? Anyway Int32 size is 2,147.483.647 it is pretty much even for very-very big system, but if this number is still not enough I may go with Int64, in that cases I may have 9,223.372.036.854.775.807 rows. Pretty much huh? From another hand, M$ using Guids as PK in their ASPNetMembership implementation. [aspnetdb].[aspnet_Users] - PK UserId Type uniqueidentifier, should be some reasons/explanation why the did it?! May be some one has any ideas/experience about that?

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