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  • Is MVVM pointless?

    - by joebeazelman
    Is orthodox MVVM implementation pointless? I am creating a new application and I considered Windows Forms and WPF. I chose WPF because it's future-proof and offer lots of flexibility. There is less code and easier to make significant changes to your UI using XAML. Since the choice for WPF is obvious, I figured that I may as well go all the way by using MVVM as my application architecture since it offers blendability, separation concerns and unit testability. Theoretically, it seems beautiful like the holy grail of UI programming. This brief adventure; however, has turned into a real headache. As expected in practice, I’m finding that I’ve traded one problem for another. I tend to be an obsessive programmer in that I want to do things the right way so that I can get the right results and possibly become a better programmer. The MVVM pattern just flunked my test on productivity and has just turned into a big yucky hack! The clear case in point is adding support for a Modal dialog box. The correct way is to put up a dialog box and tie it to a view model. Getting this to work is difficult. In order to benefit from the MVVM pattern, you have to distribute code in several places throughout the layers of your application. You also have to use esoteric programming constructs like templates and lamba expressions. Stuff that makes you stare at the screen scratching your head. This makes maintenance and debugging a nightmare waiting to happen as I recently discovered. I had an about box working fine until I got an exception the second time I invoked it, saying that it couldn’t show the dialog box again once it is closed. I had to add an event handler for the close functionality to the dialog window, another one in the IDialogView implementation of it and finally another in the IDialogViewModel. I thought MVVM would save us from such extravagant hackery! There are several folks out there with competing solutions to this problem and they are all hacks and don’t provide a clean, easily reusable, elegant solution. Most of the MVVM toolkits gloss over dialogs and when they do address them, they are just alert boxes that don’t require custom interfaces or view models. I’m planning on giving up on the MVVM view pattern, at least its orthodox implementation of it. What do you think? Has it been worth the trouble for you if you had any? Am I just a incompetent programmer or does MVVM not what it's hyped up to be?

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  • Which OAuth library do you find works best for Objective-C/iPhone?

    - by Brennan
    I have been looking to switch to OAuth for my Twitter integration code and now that there is a deadline in less than 7 weeks (see countdown link) it is even more important to make the jump to OAuth. I have been doing Basic Authentication which is extremely easy. Unfortunately OAuth does not appear to be something that I would whip together in a couple of hours. http://www.countdowntooauth.com/ So I am looking to use a library. I have put together the following list. MPOAuth MGTwitterEngine OAuthConsumer I see that MPOAuth has some great features with a good deal of testing code in place but there is one big problem. It does not work. The sample iPhone project that is supposed to authenticate with Twitter causes an error which others have identified and logged as a bug. http://code.google.com/p/mpoauthconnection/issues/detail?id=29 The last code change was March 11 and this bug was filed on March 30. It has been over a month and this critical bug has not been fixed yet. So I have moved on to MGTwitterEngine. I pulled down the source code and loaded it up in Xcode. Immediately I find that there are a few dependencies and the README file does not have a clear list of steps to fetch those dependencies and integrate them with the project so that it builds successfully. I see this as a sign that the project is not mature enough for prime time. I see also that the project references 2 libraries for JSON when one should be enough. One is TouchJSON which has worked well for me so I am again discouraged from relying on this project for my applications. I did find that MGTwitterEngine makes use of OAuthConsumer which is one of many OAuth projects hosted by an OAuth project on Google Code. http://code.google.com/p/oauth/ http://code.google.com/p/oauthconsumer/wiki/UsingOAuthConsumer It looks like OAuthConsumer is a good choice at first glance. It is hosted with other OAuth libraries and has some nice documentation with it. I pulled down the code and it builds without errors but it does have many warnings. And when I run the new Build and Analyze feature in Xcode 3.2 I see 50 analyzer results. Many are marked as potential memory leaks which would likely lead to instability in any app which uses this library. It seems there is no clear winner and I have to go with something before the big Twitter OAuth deadline. Any suggestions?

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  • What Is The Best Database For Delphi Desktop Applications That Supports Stored Procedures?

    - by Cape Cod Gunny
    I started with Turbo Pascal 3, went to TP5, Bought TP6 called Borland the next day and downgraded to TP5.5. Bought Delphi 3, and now have Delphi 5 Enterprise. I sort of lost interest in writing code about 4-5 years ago for two reasons; Spent all day writing ASP & SQL for someone else. PC Techniques magazine went away. I've got a few programs in the shareware market that are solid performers but are in need of serious updating. I love Delphi or did when it was Borland (before Borland bought DBase and all the other crap), I'd like to salvage as much of my D5E code as possible but I doubt I can. I plan on upgrading to Delphi 2010. My next software release needs to interact with a database. I'm very proficient with MS Sql and like to put all of the database code in stored procedures. What is the best database choice that interacts well with Delphi, allows stored procedures and is so easy to deploy that even the Geico gecko could deploy it? 10/25/2009 18:53 PM EST Re-Opened After Reading Install Docs for Delphi 2010 I downloaded a trial version of Delphi 2010 and unzipped the install. I've been reading the install docs included in the package. I started with the install.htm inside the zip package. install.htm wisely tells you to see the following two articles: Installation Notes: http://edn.embarcadero.com/article/39754 Release Notes: http://edn.embarcadero.com/article/39758 the release notes state the following... MSSQL driver requires the installation of the SQL Native Client. SQL Native Client 2008 is required for dbxmss.dll. SQL Native Client 2005 is required for dbxmss9.dll I checked my machine to see if SQL Native Client is installed. Nope. I wasn't done reading the docs so I made a note to install SQL Native Client. I googled dbxmss.dll and dbxmss9.dll and found a very interesting thread on the Embarcadero forums. read thread here. After reading this thread and some careful thought I don't think I will be using Microsoft SQL Express. I can't rely on my customers having the right drivers installed. So, I'm back to looking for a different solution. If I'm selling a $40 product to the general masses I need to have a bulletproof solution that doesn't require my brand new customer to update their machine before my software will work.

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  • Java language features which have no equivalent in C#

    - by jthg
    Having mostly worked with C#, I tend to think in terms of C# features which aren't available in Java. After working extensively with Java over the last year, I've started to discover Java features that I wish were in C#. Below is a list of the ones that I'm aware of. Can anyone think of other Java language features which a person with a C# background may not realize exists? The articles http://www.25hoursaday.com/CsharpVsJava.html and http://en.wikipedia.org/wiki/Comparison_of_Java_and_C_Sharp give a very extensive list of differences between Java and C#, but I wonder whether I missed anything in the (very) long articles. I can also think of one feature (covariant return type) which I didn't see mentioned in either article. Please limit answers to language or core library features which can't be effectively implemented by your own custom code or third party libraries. Covariant return type - a method can be overridden by a method which returns a more specific type. Useful when implementing an interface or extending a class and you want a method to override a base method, but return a type more specific to your class. Enums are classes - an enum is a full class in java, rather than a wrapper around a primitive like in .Net. Java allows you to define fields and methods on an enum. Anonymous inner classes - define an anonymous class which implements a method. Although most of the use cases for this in Java are covered by delegates in .Net, there are some cases in which you really need to pass multiple callbacks as a group. It would be nice to have the choice of using an anonymous inner class. Checked exceptions - I can see how this is useful in the context of common designs used with Java applications, but my experience with .Net has put me in a habit of using exceptions only for unrecoverable conditions. I.E. exceptions indicate a bug in the application and are only caught for the purpose of logging. I haven't quite come around to the idea of using exceptions for normal program flow. strictfp - Ensures strict floating point arithmetic. I'm not sure what kind of applications would find this useful. fields in interfaces - It's possible to declare fields in interfaces. I've never used this. static imports - Allows one to use the static methods of a class without qualifying it with the class name. I just realized today that this feature exists. It sounds like a nice convenience.

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  • Smooth animation using MatrixTransform?

    - by Mattias Konradsson
    I'm trying to do an Matrix animation where I both scale and transpose a canvas at the same time. The only approach I found was using a MatrixTransform and MatrixAnimationUsingKeyFrames. Since there doesnt seem to be any interpolation for matrices built in (only for path/rotate) it seems the only choice is to try and build the interpolation and DiscreteMatrixKeyFrame's yourself. I did a basic implementation of this but it isnt exactly smooth and I'm not sure if this is the best way and how to handle framerates etc. Anyone have suggestions for improvement? Here's the code: MatrixAnimationUsingKeyFrames anim = new MatrixAnimationUsingKeyFrames(); int duration = 1; anim.KeyFrames = Interpolate(new Point(0, 0), centerPoint, 1, factor,100,duration); this.matrixTransform.BeginAnimation(MatrixTransform.MatrixProperty, anim,HandoffBehavior.Compose); public MatrixKeyFrameCollection Interpolate(Point startPoint, Point endPoint, double startScale, double endScale, double framerate,double duration) { MatrixKeyFrameCollection keyframes = new MatrixKeyFrameCollection(); double steps = duration * framerate; double milliSeconds = 1000 / framerate; double timeCounter = 0; double diffX = Math.Abs(startPoint.X- endPoint.X); double xStep = diffX / steps; double diffY = Math.Abs(startPoint.Y - endPoint.Y); double yStep = diffY / steps; double diffScale= Math.Abs(startScale- endScale); double scaleStep = diffScale / steps; if (endPoint.Y < startPoint.Y) { yStep = -yStep; } if (endPoint.X < startPoint.X) { xStep = -xStep; } if (endScale < startScale) { scaleStep = -scaleStep; } Point currentPoint = new Point(); double currentScale = startScale; for (int i = 0; i < steps; i++) { keyframes.Add(new DiscreteMatrixKeyFrame(new Matrix(currentScale, 0, 0, currentScale, currentPoint.X, currentPoint.Y), KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(timeCounter)))); currentPoint.X += xStep; currentPoint.Y += yStep; currentScale += scaleStep; timeCounter += milliSeconds; } keyframes.Add(new DiscreteMatrixKeyFrame(new Matrix(endScale, 0, 0, endScale, endPoint.X, endPoint.Y), KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(0)))); return keyframes; }

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  • Fulltext search for django : Mysql not so bad ? (vs sphinx, xapian)

    - by Eric
    I am studying fulltext search engines for django. It must be simple to install, fast indexing, fast index update, not blocking while indexing, fast search. After reading many web pages, I put in short list : Mysql MYISAM fulltext, djapian/python-xapian, and django-sphinx I did not choose lucene because it seems complex, nor haystack as it has less features than djapian/django-sphinx (like fields weighting). Then I made some benchmarks, to do so, I collected many free books on the net to generate a database table with 1 485 000 records (id,title,body), each record is about 600 bytes long. From the database, I also generated a list of 100 000 existing words and shuffled them to create a search list. For the tests, I made 2 runs on my laptop (4Go RAM, Dual core 2.0Ghz): the first one, just after a server reboot to clear all caches, the second is done juste after in order to test how good are cached results. Here are the "home made" benchmark results : 1485000 records with Title (150 bytes) and body (450 bytes) Mysql 5.0.75/Ubuntu 9.04 Fulltext : ========================================================================== Full indexing : 7m14.146s 1 thread, 1000 searchs with single word randomly taken from database : First run : 0:01:11.553524 next run : 0:00:00.168508 Mysql 5.5.4 m3/Ubuntu 9.04 Fulltext : ========================================================================== Full indexing : 6m08.154s 1 thread, 1000 searchs with single word randomly taken from database : First run : 0:01:11.553524 next run : 0:00:00.168508 1 thread, 100000 searchs with single word randomly taken from database : First run : 9m09s next run : 5m38s 1 thread, 10000 random strings (random strings should not be found in database) : just after the 100000 search test : 0:00:15.007353 1 thread, boolean search : 1000 x (+word1 +word2) First run : 0:00:21.205404 next run : 0:00:00.145098 Djapian Fulltext : ========================================================================== Full indexing : 84m7.601s 1 thread, 1000 searchs with single word randomly taken from database with prefetch : First run : 0:02:28.085680 next run : 0:00:14.300236 python-xapian Fulltext : ========================================================================== 1 thread, 1000 searchs with single word randomly taken from database : First run : 0:01:26.402084 next run : 0:00:00.695092 django-sphinx Fulltext : ========================================================================== Full indexing : 1m25.957s 1 thread, 1000 searchs with single word randomly taken from database : First run : 0:01:30.073001 next run : 0:00:05.203294 1 thread, 100000 searchs with single word randomly taken from database : First run : 12m48s next run : 9m45s 1 thread, 10000 random strings (random strings should not be found in database) : just after the 100000 search test : 0:00:23.535319 1 thread, boolean search : 1000 x (word1 word2) First run : 0:00:20.856486 next run : 0:00:03.005416 As you can see, Mysql is not so bad at all for fulltext search. In addition, its query cache is very efficient. Mysql seems to me a good choice as there is nothing to install (I need just to write a small script to synchronize an Innodb production table to a MyISAM search table) and as I do not really need advanced search feature like stemming etc... Here is the question : What do you think about Mysql fulltext search engine vs sphinx and xapian ?

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  • From a 3D modeler to an iPhone app - what are best practices?

    - by bonkey
    I am quite new in 3D programming on iPhone and I would like to ask for hints about organizing a work between designers and programmers on that platform. Most of all: what kind of tools, libraries or plugins cooperate the best on both sides. Although I consider the question as looking for general best-practices advice I would like to find a solution for my current situation which I describe further, too. I've already done some research and found following libraries: SIO2 Khronos OpenGL ES 1.x SDK for PowerVR MBX Unity3D Oolong Game Engine I've checked modellers or plugins to them giving output formats readable by those tools: obj2opengl Wavefront OBJ to plain header file converter Blender with SIO2 exporter iphonewavefrontloader Cheetah3D PVRGeoPOD for 3DS / Maya Unfortunately I still have no clear vision how to combine any of that tools to get a desinger's work in an application. I look for a way of getting it in the most possible complete way: models, lights, scenes, textures, maybe some simple animations (but rather no game-like physics), but I still got nothing. And here comes my situation: I would like to find right way to present few (but quite complicated) models from a single scene. The designers mostly use 3DS Max 9, sometimes 10 (which partly prevents using PVRGeoPOD) and are rather reluctant to switch to something else but if there's no other choice I suppose it would be possible. The basic rule I've already found in some places "use Wavefront OBJ" not always works. I haven't got any acceptable results with production files, actually. The only things worked fine were some mere examples. Some of my models did imported incomplete, sometimes exporters hung or generated enormous files not really useful on an iPhone, sometimes enabling textures (with GL_TEXTURE_2D) just crashed an app. I know it might be a problem with too complicated models or my mistakes coming from inexeperience but I am not able to find any guidelines for that process to have streamlined cooperation with designers. I am even willing to write some things from scratch in pure OpenGL-ES if it's necessary, but I would like to avoid what might be avoided and get the most from the model files. The best would be the effect I saw on some SIO2 tutorials: export, build & go. But at that moment I've got only "import, wrong", "import, where are textures?", "import, that almost looks fine, export, hang" and so on... Is it really so much frustrating or I am just missed something obvious? Can anybody share his/her experience in that field and tell what kind of software uses for "making things happen"?

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  • How to Practice Unix Programming in C?

    - by danben
    After five years of professional Java (and to a lesser extent, Python) programming and slowly feeling my CS education slip away, I decided I wanted to broaden my horizons / general usefulness to the world and do something that feels more (to me) like I really have an influence over the machine. I chose to learn C and Unix programming since I feel like that is where many of the most interesting problems are. My end goal is to be able to do this professionally, if for no other reason than the fact that I have to spend 40-50 hours per week on work that pays the bills, so it may as well also be the type of coding I want to get better at. Of course, you don't get hired to do things you haven't dont before, so for now I am ramping up on my own. To this end, I started with K&R, which was a great resource in part due to the exercises spread throughout each chapter. After that I moved on to Computer Systems: A Programmer's Perspective, followed by ten chapters of Advanced Programming in the Unix Environment. When I am done with this book, I will read Unix Network Programming. What I'm missing in the Stevens books is the lack of programming problems; they mainly document functionality and provide examples, with a few end-of-chapter questions following. I feel that I would benefit much more from being challenged to use the knowledge in each chapter ala K&R. I could write some test program for each function, but this is a less desirable method as (1) I would probably be less motivated than if I were rising to some external challenge, and (2) I will naturally only think to use the function in the ways that have already occurred to me. So, I'd like to get some recommendations on how to practice. Obviously, my first choice would be to find some resource that has Unix programming challenges. I have also considered finding and attempting to contribute to some open source C project, but this is a bit daunting as there would be some overhead in learning to use the software, then learning the codebase. The only open-source C project I can think of that I use regularly is Python, and I'm not sure how easy that would be to get started on. That said, I'm open to all kinds of suggestions as there are likely things I haven't even thought of.

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  • Is One Tool or a Suite of Tools Better for Scrum?

    - by Rob Wells
    G'day, Edit: We've been using Scrum very successfully for several years on several projects of varying sizes. In fact, our team developed the successful iPlayer project for the BBC using a classical Scrum approach. After using various combinations of tools, some high-tech, some low-tech, across these projects we now wish to try adopting a suitable tool suite. Our manager is to some extent attempting to force the adoption of a single suite of tools for Scrum. I've looked at the SO question "Best Scrum tools" and most people seem to recommend either: a suite of low-tech solutions, e.g. whiteboards, post-its, index cards, etc., or a monolithic tool that tries to satisfy as much as possible of the process, e.g. Agilo, Mingle, ScrumWorks, Target Process, etc. Our team is currently evaluating several different Scrum tools. However, we are looking at selecting a single, monolithic tool, e.g. Agilo. All of the "one-stop" solutions have their strengths and weaknesses with the serious enterprise type solutions being the best sort of fit. But all have some short comings. After reading the paper "Peer Code Review: An Agile Process" over at SmartBear I started wondering if we were trying to force adoption of a tool on a "best fit" basis. I think you can take a couple of reference artefacts of the Scrum development process, say user stories, epics and themes, and the code base which must use a well-known SCM, e.g. SVN, Hg, etc. Then if we take that as the common reference points for the tools employed then we would be able to use a group of tools to handle the different aspects of the Scrum process rather than try forcing a fit of a single tool would is a bit like forcing a square peg into the round hole. In this way, providing you've agreed your common reference points, you can use several tools, each performing their role better than a could be done by a single component in a monolithic tool suite. Is this a more sensible approach? Are the two reference points I mentioned above suitable, or is their a better choice of points where the tools would meet? cheers,

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  • Data denormalization and C# objects DB serialization

    - by Robert Koritnik
    I'm using a DB table with various different entities. This means that I can't have an arbitrary number of fields in it to save all kinds of different entities. I want instead save just the most important fields (dates, reference IDs - kind of foreign key to various other tables, most important text fields etc.) and an additional text field where I'd like to store more complete object data. the most obvious solution would be to use XML strings and store those. The second most obvious choice would be JSON, that usually shorter and probably also faster to serialize/deserialize... And is probably also faster. But is it really? My objects also wouldn't need to be strictly serializable, because JsonSerializer is usually able to serialize anything. Even anonymous objects, that may as well be used here. What would be the most optimal solution to solve this problem? Additional info My DB is highly normalised and I'm using Entity Framework, but for the purpose of having external super-fast fulltext search functionality I'm sacrificing a bit DB denormalisation. Just for the info I'm using SphinxSE on top of MySql. Sphinx would return row IDs that I would use to fast query my index optimised conglomerate table to get most important data from it much much faster than querying multiple tables all over my DB. My table would have columns like: RowID (auto increment) EntityID (of the actual entity - but not directly related because this would have to point to different tables) EntityType (so I would be able to get the actual entity if needed) DateAdded (record timestamp when it's been added into this table) Title Metadata (serialized data related to particular entity type) This table would be indexed with SPHINX indexer. When I would search for data using this indexer I would provide a series of EntityIDs and a limit date. Indexer would have to return a very limited paged amount of RowIDs ordered by DateAdded (descending). I would then just join these RowIDs to my table and get relevant results. So this won't actually be full text search but a filtering search. Getting RowIDs would be very fast this way and getting results back from the table would be much faster than comparing EntityIDs and DateAdded comparisons even though they would be properly indexed.

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  • imagick showing script url instead of image

    - by Raz
    Hi, currently i'm trying to use imagick to generate some images without saving them on the server and then outputting to the browser, my method of choice was image magic with the imagick extension for php. I read the documentation, and i'm sure the package is installed on my machine (windows xp, with xampp). the class is installed imagick module enabled imagick module version 2.0.0-alpha imagick classes Imagick, ImagickDraw, ImagickPixel, ImagickPixelIterator ImageMagick version ImageMagick 6.3.3 04/21/07 Q16 http://www.imagemagick.org ImageMagick release date 04/21/07 ImageMagick Number of supported formats: 164 ImageMagick Supported formats A, ART, AVI, AVS, B, BIE, BMP, BMP2, BMP3, C, CACHE, CAPTION, CIN, CIP, CLIP, CLIPBOARD, CMYK, CMYKA, CUR, CUT, DCM, DCX, DFONT, DPS, DPX, EMF, EPDF, EPI, EPS, EPS2, EPS3, EPSF, EPSI, EPT, EPT2, EPT3, FAX, FITS, FRACTAL, FTS, G, G3, GIF, GIF87, GRADIENT, GRAY, HISTOGRAM, HTM, HTML, ICB, ICO, ICON, INFO, JBG, JBIG, JNG, JP2, JPC, JPEG, JPG, JPX, K, LABEL, M, M2V, MAP, MAT, MATTE, MIFF, MNG, MONO, MPC, MPEG, MPG, MSL, MSVG, MTV, MVG, NULL, O, OTB, OTF, PAL, PALM, PAM, PATTERN, PBM, PCD, PCDS, PCL, PCT, PCX, PDB, PDF, PFA, PFB, PGM, PGX, PICON, PICT, PIX, PJPEG, PLASMA, PNG, PNG24, PNG32, PNG8, PNM, PPM, PREVIEW, PS, PS2, PS3, PSD, PTIF, PWP, R, RAS, RGB, RGBA, RGBO, RLA, RLE, SCR, SCT, SFW, SGI, SHTML, STEGANO, SUN, SVG, SVGZ, TEXT, TGA, THUMBNAIL, TIFF, TILE, TIM, TTC, TTF, TXT, UIL, UYVY, VDA, VICAR, VID, VIFF, VST, WBMP, WMF, WMFWIN32, WMZ, WPG, X, XBM, XC, XCF, XPM, XV, XWD, Y, YCbCr, YCbCrA, YUV this is from the phpinfo so i know i have it installed, the thing is when i try to generate an image and save it, it works flawlessly, but when i try to output the image directly, i get the script url as an image $draw = new ImagickDraw(); $draw->setFont('AnkeCalligraph.TTF'); $draw->setFontSize(52); $draw->annotation(110, 110, "Hello World!"); $draw->annotation(50, 220, "Hello World!"); $canvas = new Imagick('./pictures/test_live.PNG'); $canvas->drawImage($draw); $canvas->setImageFormat('png'); header("Content-Type: image/png"); echo $canvas; this is the code used. if i use writeimage, then the file on the server is created with no problems. does anyone have any ideas what i'm doing wrong ?

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  • Bottom button bar overlaps the last element of Listview!!

    - by elto
    I have a listview which is part of an Activity. I want user to have a choice for batch deleting the items in the listview, so when he chooses the corresponding option from the menu, every list item gets a checkbox next to it. When user clicks any checkbox, a button bar is to slide up from bottom (as in gmail app) and clicking delete button deletes the selected items, however clicking cancel button on the bar would uncheck all the checked items. This is my page layout.xml: <?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" android:background="@android:color/transparent" > <FrameLayout android:layout_width="fill_parent" android:layout_height="fill_parent" > <LinearLayout android:id="@+id/list_area" android:layout_width="fill_parent" android:layout_height="fill_parent" android:layout_weight="1" > <ListView android:id="@+id/mylist" android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="@android:color/transparent" android:drawSelectorOnTop="false" android:layout_weight="1" /> <TextView android:id="@+id/empty_list_message" android:layout_width="fill_parent" android:layout_height="wrap_content" android:textColor="#FFFFFF" android:layout_gravity="center_vertical|center_horizontal" android:text="@string/msg_for_emptyschd" android:layout_margin="14dip" android:layout_weight="1" /> </LinearLayout> <RelativeLayout android:id="@+id/bottom_action_bar" android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content" android:background="@drawable/schedule_bottom_actionbar_border" android:layout_marginBottom="2dip" android:layout_gravity="bottom" android:visibility="gone" > <Button android:id="@+id/delete_selecteditems_button" android:text="Deleted Selected" android:layout_width="140dip" android:layout_height="40dip" android:layout_alignParentLeft="true" android:layout_marginLeft="3dip" android:layout_marginTop="3dip" /> <Button android:id="@+id/cancel_button" android:text="Cancel" android:layout_width="140dip" android:layout_height="40dip" android:layout_alignParentRight="true" android:layout_marginRight="3dip" android:layout_marginTop="3dip" /> </RelativeLayout> </FrameLayout> </LinearLayout> so far, I have got everything working except that when the bottom bar becomes visible upon checkbox selection, it overlaps the last element of the list. All other list items can be scrolled up, but you cant scroll up the very last item of the list, therefore user can not select that item if he intends to. Here is the screenshot of the overlap. I have tried using the listview footer option, but that appends the bar to the end of the list instead of keeping it fixed at the bottom of the screen. Is there a way I could "raise" the listview enough so that the overlap wont happen?? BTW, I have already tried adding the bottom-margin to the listview itself, or the LinearLayout wrapping the listview right before making the button-bar visible, but it introduces other bugs like clicking one checkbox checks some another checkbox in listview.

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  • How do I create a partial function with generics in scala?

    - by Matteo Caprari
    Hello. I'm trying to write a performance measurements library for Scala. My idea is to transparently 'mark' sections so that the execution time can be collected. Unfortunately I wasn't able to bend the compiler to my will. An admittedly contrived example of what I have in mind: // generate a timing function val myTimer = mkTimer('myTimer) // see how the timing function returns the right type depending on the // type of the function it is passed to it val act = actor { loop { receive { case 'Int => val calc = myTimer { (1 to 100000).sum } val result = calc + 10 // calc must be Int self reply (result) case 'String => val calc = myTimer { (1 to 100000).mkString } val result = calc + " String" // calc must be String self reply (result) } Now, this is the farthest I got: trait Timing { def time[T <: Any](name: Symbol)(op: => T) :T = { val start = System.nanoTime val result = op val elapsed = System.nanoTime - start println(name + ": " + elapsed) result } def mkTimer[T <: Any](name: Symbol) : (() => T) => () => T = { type c = () => T time(name)(_ : c) } } Using the time function directly works and the compiler correctly uses the return type of the anonymous function to type the 'time' function: val bigString = time('timerBigString) { (1 to 100000).mkString("-") } println (bigString) Great as it seems, this pattern has a number of shortcomings: forces the user to reuse the same symbol at each invocation makes it more difficult to do more advanced stuff like predefined project-level timers does not allow the library to initialize once a data structure for 'timerBigString So here it comes mkTimer, that would allow me to partially apply the time function and reuse it. I use mkTimer like this: val myTimer = mkTimer('aTimer) val myString= myTimer { (1 to 100000).mkString("-") } println (myString) But I get a compiler error: error: type mismatch; found : String required: () => Nothing (1 to 100000).mkString("-") I get the same error if I inline the currying: val timerBigString = time('timerBigString) _ val bigString = timerBigString { (1 to 100000).mkString("-") } println (bigString) This works if I do val timerBigString = time('timerBigString) (_: String), but this is not what I want. I'd like to defer typing of the partially applied function until application. I conclude that the compiler is deciding the return type of the partial function when I first create it, chosing "Nothing" because it can't make a better informed choice. So I guess what I'm looking for is a sort of late-binding of the partially applied function. Is there any way to do this? Or maybe is there a completely different path I could follow? Well, thanks for reading this far -teo

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  • Java Nimbus LAF with transparent text fields

    - by Software Monkey
    I have an application that uses disabled JTextFields in several places which are intended to be transparent - allowing the background to show through instead of the text field's normal background. When running the new Nimbus LAF these fields are opaque (despite setting setOpaque(false)), and my UI is broken. It's as if the LAF is ignoring the opaque property. Setting a background color explicitly is both difficult in several places, and less than optimal due to background images actually doesn't work - it still paints it's LAF default background over the top, leaving a border-like appearance (the splash screen below has the background explicitly set to match the image). Any ideas on how I can get Nimbus to not paint the background for a JTextField? Note: I need a JTextField, rather than a JLabel, because I need the thread-safe setText(), and wrapping capability. Note: My fallback position is to continue using the system LAF, but Nimbus does look substantially better. See example images below. Conclusions The surprise at this behavior is due to a misinterpretation of what setOpaque() is meant to do - from the Nimbus bug report: This is a problem the the orginal design of Swing and how it has been confusing for years. The issue is setOpaque(false) has had a side effect in exiting LAFs which is that of hiding the background which is not really what it is ment for. It is ment to say that the component my have transparent parts and swing should paint the parent component behind it. It's unfortunate that the Nimbus components also appear not to honor setBackground(null) which would otherwise be the recommended way to stop the background painting. Setting a fully transparent background seems unintuitive to me. In my opinion, setOpaque()/isOpaque() is a faulty public API choice which should have been only: public boolean isFullyOpaque(); I say this, because isOpaque()==true is a contract with Swing that the component subclass will take responsibility for painting it's entire background - which means the parent can skip painting that region if it wants (which is an important performance enhancement). Something external cannot directly change this contract (legitimately), whose fulfillment may be coded into the component. So the opacity of the component should not have been settable using setOpaque(). Instead something like setBackground(null) should cause many components to "no long have a background" and therefore become not fully opaque. By way of example, in an ideal world most components should have an isOpaque() that looks like this: public boolean isOpaque() { return (background!=null); }

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  • JSON Post To Rails From Android

    - by Stealthnh
    I'm currently working on an android app that interfaces with a Ruby on Rails app through XML and JSON. I can currently pull all my posts from my website through XML but I can't seem to post via JSON. My app currently builds a JSON object from a form that looks a little something like this: { "post": { "other_param": "1", "post_content": "Blah blah blah" } } On my server I believe the Create method in my Posts Controller is set up correctly: def create @post = current_user.posts.build(params[:post]) respond_to do |format| if @post.save format.html { redirect_to @post, notice: 'Post was successfully created.' } format.json { render json: @post, status: :created, location: @post } format.xml { render xml: @post, status: :created, location: @post } else format.html { render action: "new" } format.json { render json: @post.errors, status: :unprocessable_entity } format.xml { render xml: @post.errors, status: :unprocessable_entity } end end end And in my android app I have a method that takes that JSON Object I posted earlier as a parameter along with the username and password for being authenticated (Authentication is working I've tested it, and yes Simple HTTP authentication is probably not the best choice but its a quick and dirty fix) and it then sends the JSON Object through HTTP POST to the rails server. This is that method: public static void sendPost(JSONObject post, String email, String password) { DefaultHttpClient client = new DefaultHttpClient(); client.getCredentialsProvider().setCredentials(new AuthScope(null,-1), new UsernamePasswordCredentials(email,password)); HttpPost httpPost = new HttpPost("http://mysite.com/posts"); JSONObject holder = new JSONObject(); try { holder.put("post", post); StringEntity se = new StringEntity(holder.toString()); Log.d("SendPostHTTP", holder.toString()); httpPost.setEntity(se); httpPost.setHeader("Content-Type","application/json"); } catch (UnsupportedEncodingException e) { Log.e("Error",""+e); e.printStackTrace(); } catch (JSONException js) { js.printStackTrace(); } HttpResponse response = null; try { response = client.execute(httpPost); } catch (ClientProtocolException e) { e.printStackTrace(); Log.e("ClientProtocol",""+e); } catch (IOException e) { e.printStackTrace(); Log.e("IO",""+e); } HttpEntity entity = response.getEntity(); if (entity != null) { try { entity.consumeContent(); } catch (IOException e) { Log.e("IO E",""+e); e.printStackTrace(); } } } Currently when I call this method and pass it the correct JSON Object it doesn't do anything and I have no clue why or how to figure out what is going wrong. Is my JSON still formatted wrong, does there really need to be that holder around the other data? Or do I need to use something other than HTTP POST? Or is this just something on the Rails end? A route or controller that isn't right? I'd be really grateful if someone could point me in the right direction, because I don't know where to go from here.

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  • Non-linear regression models in PostgreSQL using R

    - by Dave Jarvis
    Background I have climate data (temperature, precipitation, snow depth) for all of Canada between 1900 and 2009. I have written a basic website and the simplest page allows users to choose category and city. They then get back a very simple report (without the parameters and calculations section): The primary purpose of the web application is to provide a simple user interface so that the general public can explore the data in meaningful ways. (A list of numbers is not meaningful to the general public, nor is a website that provides too many inputs.) The secondary purpose of the application is to provide climatologists and other scientists with deeper ways to view the data. (Using too many inputs, of course.) Tool Set The database is PostgreSQL with R (mostly) installed. The reports are written using iReport and generated using JasperReports. Poor Model Choice Currently, a linear regression model is applied against annual averages of daily data. The linear regression model is calculated within a PostgreSQL function as follows: SELECT regr_slope( amount, year_taken ), regr_intercept( amount, year_taken ), corr( amount, year_taken ) FROM temp_regression INTO STRICT slope, intercept, correlation; The results are returned to JasperReports using: SELECT year_taken, amount, year_taken * slope + intercept, slope, intercept, correlation, total_measurements INTO result; JasperReports calls into PostgreSQL using the following parameterized analysis function: SELECT year_taken, amount, measurements, regression_line, slope, intercept, correlation, total_measurements, execute_time FROM climate.analysis( $P{CityId}, $P{Elevation1}, $P{Elevation2}, $P{Radius}, $P{CategoryId}, $P{Year1}, $P{Year2} ) ORDER BY year_taken This is not an optimal solution because it gives the false impression that the climate is changing at a slow, but steady rate. Questions Using functions that take two parameters (e.g., year [X] and amount [Y]), such as PostgreSQL's regr_slope: What is a better regression model to apply? What CPAN-R packages provide such models? (Installable, ideally, using apt-get.) How can the R functions be called within a PostgreSQL function? If no such functions exist: What parameters should I try to obtain for functions that will produce the desired fit? How would you recommend showing the best fit curve? Keep in mind that this is a web app for use by the general public. If the only way to analyse the data is from an R shell, then the purpose has been defeated. (I know this is not the case for most R functions I have looked at so far.) Thank you!

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  • python Socket.IO client for sending broadcast messages to TornadIO2 server

    - by Alp
    I am building a realtime web application. I want to be able to send broadcast messages from the server-side implementation of my python application. Here is the setup: socketio.js on the client-side TornadIO2 server as Socket.IO server python on the server-side (Django framework) I can succesfully send socket.io messages from the client to the server. The server handles these and can send a response. In the following i will describe how i did that. Current Setup and Code First, we need to define a Connection which handles socket.io events: class BaseConnection(tornadio2.SocketConnection): def on_message(self, message): pass # will be run if client uses socket.emit('connect', username) @event def connect(self, username): # send answer to client which will be handled by socket.on('log', function) self.emit('log', 'hello ' + username) Starting the server is done by a Django management custom method: class Command(BaseCommand): args = '' help = 'Starts the TornadIO2 server for handling socket.io connections' def handle(self, *args, **kwargs): autoreload.main(self.run, args, kwargs) def run(self, *args, **kwargs): port = settings.SOCKETIO_PORT router = tornadio2.TornadioRouter(BaseConnection) application = tornado.web.Application( router.urls, socket_io_port = port ) print 'Starting socket.io server on port %s' % port server = SocketServer(application) Very well, the server runs now. Let's add the client code: <script type="text/javascript"> var sio = io.connect('localhost:9000'); sio.on('connect', function(data) { console.log('connected'); sio.emit('connect', '{{ user.username }}'); }); sio.on('log', function(data) { console.log("log: " + data); }); </script> Obviously, {{ user.username }} will be replaced by the username of the currently logged in user, in this example the username is "alp". Now, every time the page gets refreshed, the console output is: connected log: hello alp Therefore, invoking messages and sending responses works. But now comes the tricky part. Problems The response "hello alp" is sent only to the invoker of the socket.io message. I want to broadcast a message to all connected clients, so that they can be informed in realtime if a new user joins the party (for example in a chat application). So, here are my questions: How can i send a broadcast message to all connected clients? How can i send a broadcast message to multiple connected clients that are subscribed on a specific channel? How can i send a broadcast message anywhere in my python code (outside of the BaseConnection class)? Would this require some sort of Socket.IO client for python or is this builtin with TornadIO2? All these broadcasts should be done in a reliable way, so i guess websockets are the best choice. But i am open to all good solutions.

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  • Would Like Multiple Checkboxes to Update World PNG Image Using Mogrify to FloodFill Countries With C

    - by socrtwo
    Hi. I'm seeing in another forum if the best way to do this is with Javascript or Ajax but I'm wondering if there is an even easier simpler way. I'm trying to create a web service where users can check which countries they have visited from a list of 175 or so and a World map image would then instantly update with a filled color. There are other similar services, but I'm envisioning mine to be both updating from checks in checkboxes and by clicking on the target country in the displayed image say with an imagemap. Additionally other solutions display all the visited countries in the same color. I would like different colors for different countries or at least for those countries that touch. Eventually I would like to include a feature that enables the choice of which colors to assign countries. I found a Sourceforge project called pwmfccd. It's simply an open source image of the world and the coordinates on the PNG image for all the countries. You can use mogrify from ImageMagick and floodfill to fill the countries with color. I have done this successfully, locally with batch files. My ISP has told me where mogrify is located, basically "/usr/bin/mogrify". I now have a horrendously complicated cgi script which if it worked is set to redraw the world map image with each checkbox. It's here. It also redraws the whole web page with each check. The web page starts here. Of course this is not at all efficient, and I think probably the real way to go is Ajax or Javascript, so that maybe just the image gets changed and redrawn, not the whole web page. Sorry I don't even know the difference between Javascript and Ajax and their relative merits at this point. I suppose you could make just one part of the image update with each check or click on the image instead of even just the image redrawing, but I have never even heard of a hint at being able to do that for irregularly shaped image elements like countries. So I guess an Image map and sister checkbox entries tied to mogrify events redrawing the user's personal copy of the image with an image refresh would be the only way to go. So how do you do this with something other than Javascript or Ajax or is that definitely the way to go and if so, how would you do it? Or can you after all cut up a web based image into irregular puzzle shaped piece which you can redraw individually at will. Thanks in advance for reading and considering answering this post.

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  • Amusing or Sad? Network Solutions

    - by dbasnett
    When I got sick my email ended up in every drug sellers email list. Some days I get over 200 emails selling everything from Viagra to Xanax. Either they don't know what my condition is or they are telling me you are a goner, might as well chill-ax and have a good time. In order to cut down on the mail being downloaded I thought I would add all of the Junk email senders from Outlook to my Network Solution mail server. Much to my amazement I could not find that import Spammers button, so I submitted a tech support request. Here is the response: Thank you for contacting Network Solutions Customer Service Department. We are committed to creating the best Customer experience possible. One of the first ways we can demonstrate our commitment to this goal is to quickly and efficiently handle your recent request. We apologize for any inconvenience this might have caused you. With regard to your concern, please be advised that we cannot import blocked senders in to you e-mail servers. An alternative option is for you to create a Custom Filter that filters unwanted e-mails. To create a Custom Filter: Open a Web browser (e.g., Netscape, Microsoft Internet Explorer, etc.). Type mail.[domain name].[ext] in the address line. Login to your Network Solutions email account. Click on the Configuration left menu tab. Click on the Custom Filter link. Type the rule name. blah, blah, blah Basically add them one at a time. "We are committed to creating the best Customer experience possible." No you are not. You are trying to squeeze every nickle you can out of me. "With regard to your concern, please be advised that we cannot import blocked senders in to you e-mail servers." Maybe I should apply for a job to write those ten complicated lines of code... Maybe I should question my choice of vendors, because if they truly "cannot" then they are to stupid to have my business. It is both amusing and sad. I'll be posting this in every forum I am a member of.

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  • What are five things you hate about your favorite language?

    - by brian d foy
    There's been a cluster of Perl-hate on Stackoverflow lately, so I thought I'd bring my "Five things you hate about your favorite language" question to StackOverflow. Take your favorite language and tell me five things you hate about it. Those might be things that just annoy you, admitted design flaws, recognized performance problems, or any other category. You just have to hate it, and it has to be your favorite language. Don't compare it to another language, and don't talk about languages that you already hate. Don't talk about the things you like in your favorite language. I just want to hear the things that you hate but tolerate so you can use all of the other stuff, and I want to hear it about the language you wished other people would use. I ask this whenever someone tries to push their favorite language on me, and sometimes as an interview question. If someone can't find five things to hate about his favorite tool, he don't know it well enough to either advocate it or pull in the big dollars using it. He hasn't used it in enough different situations to fully explore it. He's advocating it as a culture or religion, which means that if I don't choose his favorite technology, I'm wrong. I don't care that much which language you use. Don't want to use a particular language? Then don't. You go through due diligence to make an informed choice and still don't use it? Fine. Sometimes the right answer is "You have a strong programming team with good practices and a lot of experience in Bar. Changing to Foo would be stupid." This is a good question for code reviews too. People who really know a codebase will have all sorts of suggestions for it, and those who don't know it so well have non-specific complaints. I ask things like "If you could start over on this project, what would you do differently?" In this fantasy land, users and programmers get to complain about anything and everything they don't like. "I want a better interface", "I want to separate the model from the view", "I'd use this module instead of this other one", "I'd rename this set of methods", or whatever they really don't like about the current situation. That's how I get a handle on how much a particular developer knows about the codebase. It's also a clue about how much of the programmer's ego is tied up in what he's telling me. Hate isn't the only dimension of figuring out how much people know, but I've found it to be a pretty good one. The things that they hate also give me a clue how well they are thinking about the subject.

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  • Sysadmin 101: How can I figure out why my server crashes and monitor performance?

    - by bflora
    I have a Drupal-powered site that seems to have neverending performance problems. It was butt-slow about 5 months ago. I brought in some guys who installed nginx for anonymous visitors, ajaxified a few queries so they wouldn't fire during page load, and helped me find a few bottlenecks in the code. For about a month, the site was significantly faster, though not "fast" by any stretch of the word. Meanwhile, I'm now shelling out $400/month to Slicehost to host a site that gets less than 5,000/uniques a day. Yes, you read that right. Go Drupal. Recently the site started crashing again and is slow again. I can't afford to hire people to come in, study my code from top to bottom, and make changes that may or may not help anymore. And I can't afford to throw more hardware at the problem. So I need to figure out what the problem is myself. Questions: When apache crashes, is it possible to find out what caused it to crash? There has to be a way, right? If so, how can I do this? Is there software I can use that will tell me which process caused my server to die? (e.g. "Apache crashed because someone visited page X." or "Apache crashed because you were importing too many RSS items from feed X.") There's got to be a way to learn this, right? What's a good, noob-friendly way to monitor my current apache performance? My developer friends tell me to "just use Top, dude," but Top shows me a bunch of numbers without any context. I have no clue what qualifies as a bad number or a good number in Top, or which processes are relevant and which aren't. Are there any noob-friendly server monitoring tools out there? Ideally, I could have a page that would give me a color-coded indicator about how apache is performing and then show me a list of processes or pages that are sucking right now. This way, I could know when performance is bad and then what's causing it to be so bad. Why does PHP memory matter? My apparently has a 30MB memory foot print. Will it run faster if I bring that number down? Thanks for any advice. I spent a year or so trying to boost my advertising income so I could hire a contractor to solve my performance woes. I didn't want to have to learn all this sysadmin voodoo. I'm now resigned to the fact that might not have a choice.

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  • Maven building for GoogleAppEngine, forced to include JDO libraries?

    - by James.Elsey
    Hi, I'm trying to build my application for GoogleAppEngine using maven. I've added the following to my pom which should "enhance" my classes after building, as suggested on the DataNucleus documentation <plugin> <groupId>org.datanucleus</groupId> <artifactId>maven-datanucleus-plugin</artifactId> <version>1.1.4</version> <configuration> <log4jConfiguration>${basedir}/log4j.properties</log4jConfiguration> <verbose>true</verbose> </configuration> <executions> <execution> <phase>process-classes</phase> <goals> <goal>enhance</goal> </goals> </execution> </executions> </plugin> According to the documentation on GoogleAppEngine, you have the choice to use JDO or JPA, I've chosen to use JPA since I have used it in the past. When I try to build my project (before I upload to GAE) using mvn clean package I get the following output [ERROR] BUILD ERROR [INFO] ------------------------------------------------------------------------ [INFO] Failed to resolve artifact. Missing: ---------- 1) javax.jdo:jdo2-api:jar:2.3-ec Try downloading the file manually from the project website. Then, install it using the command: mvn install:install-file -DgroupId=javax.jdo -DartifactId=jdo2-api -Dversion=2.3-ec -Dpackaging=jar -Dfile=/path/to/file Alternatively, if you host your own repository you can deploy the file there: mvn deploy:deploy-file -DgroupId=javax.jdo -DartifactId=jdo2-api -Dversion=2.3-ec -Dpackaging=jar -Dfile=/path/to/file -Durl=[url] -DrepositoryId=[id] Path to dependency: 1) org.datanucleus:maven-datanucleus-plugin:maven-plugin:1.1.4 2) javax.jdo:jdo2-api:jar:2.3-ec ---------- 1 required artifact is missing. for artifact: org.datanucleus:maven-datanucleus-plugin:maven-plugin:1.1.4 from the specified remote repositories: __jpp_repo__ (file:///usr/share/maven2/repository), DN_M2_Repo (http://www.datanucleus.org/downloads/maven2/), central (http://repo1.maven.org/maven2) [INFO] ------------------------------------------------------------------------ [INFO] For more information, run Maven with the -e switch [INFO] ------------------------------------------------------------------------ [INFO] Total time: 3 seconds [INFO] Finished at: Sat Apr 03 16:02:39 BST 2010 [INFO] Final Memory: 31M/258M [INFO] ------------------------------------------------------------------------ Any ideas why I should get such an error? I've searched through my entire source code and I'm not referencing JDO anywhere, so unless the app engine libraries require it, I'm not sure why I get this message.

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  • ActionListener problem

    - by thegamer
    Hello, i am trying to make an actionListener on a button in another button which has also an actionlistener and i just couldn't figure it out for some way. I am trying to make an action on the 2nd button but i couldn't figure it out.If anyone helps me i'd appreciate! here is the code below: import java.awt.; import java.awt.event.; import javax.swing.; import java.io.; import java.util.*; public class basic implements ActionListener{ public static void main(String[] args) { basic process = new basic (); } public basic(){ JFrame fan = new JFrame("Scheme"); JPanel one = new JPanel(new BorderLayout()); fan.add(one); JPanel uno = new JPanel(); uno.setLayout(new BoxLayout(uno, BoxLayout.Y_AXIS)); JButton addB = new JButton("first choice"); addB.setAlignmentX(Component.CENTER_ALIGNMENT); uno.add(addB); addDButton.setActionCommand("hehe"); addDButton.addActionListener(this); one.add(uno,BorderLayout.CENTER); fan.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); fan.setSize(500,700); fan.setLocationByPlatform(true); fan.setVisible(true); } public void actionPerformed(ActionEvent evt) { JPanel markP = new JPanel(new FlowLayout(FlowLayout.RIGHT,10,20)); JDialog dialog = new JDialog((JFrame)null); dialog.getContentPane().add(markP,BorderLayout.CENTER); if (evt.getActionCommand().equals("hehe")) { JLabel title = new JLabel("Proceed"); title.setFont(new Font("Arial",Font.BOLD,15)); markP.add(title,BorderLayout.NORTH); JButton exit = new JButton("Exit"); markP.add(exit); //here i want to create another actionListener on the exit button only without affecting the other content which is in the button "addB " so that when i click on the addB button the J dialog pops up, and than when i click on exit button the program will return to the menu.I couldn't figure it out. dialog.toFront(); dialog.setModal(true); dialog.pack(); // dialog.setLocationRelativeTo(null); // dialog.setVisible(true); } // here the code goes on but the problem is that of the actionListener which is concerned.

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  • Constraint Satisfaction Problem

    - by Carl Smotricz
    I'm struggling my way through Artificial Intelligence: A Modern Approach in order to alleviate my natural stupidity. In trying to solve some of the exercises, I've come up against the "Who Owns the Zebra" problem, Exercise 5.13 in Chapter 5. This has been a topic here on SO but the responses mostly addressed the question "how would you solve this if you had a free choice of problem solving software available?" I accept that Prolog is a very appropriate programming language for this kind of problem, and there are some fine packages available, e.g. in Python as shown by the top-ranked answer and also standalone. Alas, none of this is helping me "tough it out" in a way as outlined by the book. The book appears to suggest building a set of dual or perhaps global constraints, and then implementing some of the algorithms mentioned to find a solution. I'm having a lot of trouble coming up with a set of constraints suitable for modelling the problem. I'm studying this on my own so I don't have access to a professor or TA to get me over the hump - this is where I'm asking for your help. I see little similarity to the examples in the chapter. I was eager to build dual constraints and started out by creating (the logical equivalent of) 25 variables: nationality1, nationality2, nationality3, ... nationality5, pet1, pet2, pet3, ... pet5, drink1 ... drink5 and so on, where the number was indicative of the house's position. This is fine for building the unary constraints, e.g. The Norwegian lives in the first house: nationality1 = { :norway }. But most of the constraints are a combination of two such variables through a common house number, e.g. The Swede has a dog: nationality[n] = { :sweden } AND pet[n] = { :dog } where n can range from 1 to 5, obviously. Or stated another way: nationality1 = { :sweden } AND pet1 = { :dog } XOR nationality2 = { :sweden } AND pet2 = { :dog } XOR nationality3 = { :sweden } AND pet3 = { :dog } XOR nationality4 = { :sweden } AND pet4 = { :dog } XOR nationality5 = { :sweden } AND pet5 = { :dog } ...which has a decidedly different feel to it than the "list of tuples" advocated by the book: ( X1, X2, X3 = { val1, val2, val3 }, { val4, val5, val6 }, ... ) I'm not looking for a solution per se; I'm looking for a start on how to model this problem in a way that's compatible with the book's approach. Any help appreciated.

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  • Trying to retrieve the contents of UITableView cell on selection by user.

    - by chubsta
    Hi, this is my first post here and as i am very new (2 weeks in...) to iPhone (or any!) development i am a little unsure as to how much detail is needed or relevant, so please forgive me if I dont provide enough to be useful at this stage... Anyway, on to my problem - I have set up a UITableView-based app, which has a .plist for holding the data. The .plist has a dictionary as its root, followed by a number of Arrays, each containing the data-strings that display in the table. Everything is working fine until the point where i select a row. I have set it up so i get an alert with the results of the button press and it is here that i want to see the contents of the cell being produced. Instead of the expected string eg. "data line 1", all i get is the number of the row within the section. I have gone backwards and forwards but dont seem to be getting anywhere although i am sure it is something simple. The code compiles fine, with no warnings or errors, and if i can just get the string of the selected cell i will be well on my way, so any help appreciated. I know that I need to do more following the 'NSUInteger row = [indexPath row]; part but thats where my mind dries up... here is the relevant 'selection' section, if i need to post more code please let me know, and i really appreciate any help with this...(please forgive my 'alert' message, i was just happy at that point that i get SOMETHING back from the row selection!) (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { [tableView deselectRowAtIndexPath:indexPath animated:YES]; NSUInteger row = [indexPath row]; NSString *message = [[NSString alloc] initWithFormat: @"You selected Cell %d from this Section, "@"which is a very good choice indeed!" @"Unfortunately I can't work out how to get the info out of the cell so it's not much use at the moment!" @"Still, this is a good chance to see how much space I have in an alert box!", row]; UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"My God! It works..." message:message delegate:nil cancelButtonTitle:@"You are awesome Karl!!" otherButtonTitles:nil]; [alert show]; [message release]; [alert release]; }

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