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  • What's the best Linux backup solution?

    - by Jon Bright
    We have a four Linux boxes (all running Debian or Ubuntu) on our office network. None of these boxes are especially critical and they're all using RAID. To date, I've therefore been doing backups of the boxes by having a cron job upload tarballs containing the contents of /etc, MySQL dumps and other such changing, non-packaged data to a box at our geographically separate hosting centre. I've realised, however that the tarballs are sufficient to rebuild from, but it's certainly not a painless process to do so (I recently tried this out as part of a hardware upgrade of one of the boxes) long-term, the process isn't sustainable. Each of the boxes is currently producing a tarball of a couple of hundred MB each day, 99% of which is the same as the previous day partly due to the size issue, the backup process requires more manual intervention than I want (to find whatever 5GB file is inflating the size of the tarball and kill it) again due to the size issue, I'm leaving stuff out which it would be nice to include - the contents of users' home directories, for example. There's almost nothing of value there that isn't in source control (and these aren't our main dev boxes), but it would be nice to keep them anyway. there must be a better way So, my question is, how should I be doing this properly? The requirements are: needs to be an offsite backup (one of the main things I'm doing here is protecting against fire/whatever) should require as little manual intervention as possible (I'm lazy, and box-herding isn't my main job) should continue to scale with a couple more boxes, slightly more data, etc. preferably free/open source (cost isn't the issue, but especially for backups, openness seems like a good thing) an option to produce some kind of DVD/Blu-Ray/whatever backup from time to time wouldn't be bad My first thought was that this kind of incremental backup was what tar was created for - create a tar file once each month, add incrementally to it. rsync results to remote box. But others probably have better suggestions.

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  • How to deal with seniors' bad coding style/practices?

    - by KaluSingh Gabbar
    I am new to work but the company I work in hires a lot of non-comp-science people who are smart enough to get the work done (complex) but lack the style and practices that should help other people read their code. For example they adopt C++ but still use C-like 3 page functions which drives new folks nuts when they try to read that. Also we feel very risky changing it as it's never easy to be sure we are not breaking something. Now, I am involved in the project with these guys and I can't change the entire code base myself or design so that code looks good, what can I do in this situation? PS we actually have 3 page functions & because we do not have a concept of design, all we can do is assume what they might have thought as there is no way to know why is it designed the way it is. I am not complaining.I am asking for suggestion,already reading some books to solve the issues Pragmatic Programmer; Design portion from B.Stroustrup; Programming and principles by B.Stroustrup;

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  • Need advanced mod_rewrite assistance

    - by user1647719
    This is driving me bananas. I have tried multiple fixes, and have even found a generator (generateit.net/mod-rewrite/) to create my .htaccess files, but I cannot get this to work. The .htaccess file is being read - if I put garbage characters in, I get a 500 server error. Also, mod rewrite was working in a simpler format, but the client wants even more SEO, so here I am. My intention: Take the url of brinkofdesign.com/portfolio/123/456/some_seo_text.html and send it to brinkofdesign.com/brink_portfolio.php?catid=123&locationid=456. The full contents of my .htaccess file are: Options +FollowSymlinks RewriteEngine on RewriteBase / RewriteRule ^portfolio([^/]*)/([^/]*)/([^/]*)\.html$ /portfolio_brink.php?catid=$1&locationid=$2&page=$3 [NC,L] RewriteRule ^(.*)blog(.+)([0-9+])(.+).html$ blog.php?blogid=$3 [NC,L] RewriteRule ^blog.xml$ blogfeed.php The blog and blogfeed parts work fine. If it matters, I do have an actual portfolio.php page - could this be breaking it? There is no actual /portfolio/ folder - this is just part of the SEO nme. Also, the host is 1and1.com. Real life tests: brinkofdesign.com/portfolio/1/1/birmingham_al_corporate_branding.html loads my actual portfolio.php page - which is supposed to be a landing page for the portfolio, as opposed to the brink_portfolio.php page, which is my detail record page. No variables are passed (echoing out the contents of the $_GET array gives an empty array). Typing in an non SEO link like brinkofdesign.com/brink_portfolio.php?catid=1&locationid=1 does work correctly. Gurus, please help me!

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  • regexp target last main li in list

    - by veilig
    I need to target the starting tag of the last top level LI in a list that may or may-not contain sublists in various positions - without using CSS or Javascript. Is there a simple/elegant regexp that can help with this? I'm no guru w/ them, but it appears the need for greedy/non-greedy selectors when I'm selecting all the middle text (.*) / (.+) changes as nested lists are added and moved around in the list - and this is throwing me off. $pattern = '/^(<ul>.*)<li>(.+<\/li><\/ul>)$/'; $replacement = '$1<li id="lastLi">$3'; Perhaps there is an easier approach?? converting to XML to target the LI and then convert back? ie: Single Element <ul> <li>TARGET</li> </ul> Multiple Elements <ul> <li>foo</li> <li>TARGET</li> </ul> Nested Lists before end <ul> <li> foo <ul> <li>bar</li> </ul> <li> <li>TARGET</li> </ul> Nested List at end <ul> <li>foo</li> <li> TARGET <ul> <li>bar</li> </ul> </li> </ul>

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  • nhibernate mapping: delete collection, insert new collection with old IDs

    - by npeBeg
    my issue lokks similar to this one: (link) but i have one-to-many association: <set name="Fields" cascade="all-delete-orphan" lazy="false" inverse="true"> <key column="[TEMPLATE_ID]"></key> <one-to-many class="MyNamespace.Field, MyLibrary"/> </set> (i also tried to use ) this mapping is for Template object. this one and the Field object has their ID generators set to identity. so when i call session.Update for the Template object it works fine, well, almost: if the Field object has an Id number, UPDATE sql request is called, if the Id is 0, the INSERT is performed. But if i delete a Field object from the collection it has no effect for the Database. I found that if i also call session.Delete for this Field object, everything will be ok, but due to client-server architecture i don't know what to delete. so i decided to delete all the collection elements from the DB and call session.Update with a new collection. and i've got an issue: nhibernate performs the UPDATE operation for the Field objects that has non-zero Id, but they are removed from DB! maybe i should use some other Id generator or smth.. what is the best way to make nhibernate perform "delete all"/"insert all" routine for the collection?

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  • PHP/MySQL time zone migration

    - by El Yobo
    I have an application that currently stores timestamps in MySQL DATETIME and TIMESTAMP values. However, the application needs to be able to accept data from users in multiple time zones and show the timestamps in the time zone of other users. As such, this is how I plan to amend the application; I would appreciate any suggestions to improve the approach. Database modifications All TIMESTAMPs will be converted to DATETIME values; this is to ensure consistency in approach and to avoid having MySQL try to do clever things and convert time zones (I want to keep the conversion in PHP, as it involves less modification to the application, and will be more portable when I eventually manage to escape from MySQL). All DATETIME values will be adjusted to convert them to UTC time (currently all in Australian EST) Query modifications All usage of NOW() to be replaced with UTC_TIMESTAMP() in queries, triggers, functions, etc. Application modifications The application must store the time zone and preferred date format (e.g. US vs the rest of the world) All timestamps will be converted according to the user settings before being displayed All input timestamps will be converted to UTC according to the user settings before being input Additional notes Converting formats will be done at the application level for several main reasons The approach to converting time zones varies from DB to DB, so handing it there will be non-portable (and I really hope to be migrating away from MySQL some time in the not-to-distant future). MySQL TIMESTAMPs have limited ranges to the permitted dates (~1970 to ~2038) MySQL TIMESTAMPs have other undesirable attributes, including bizarre auto-update behaviour (if not carefully disabled) and sensitivity to the server zone settings (and I suspect I might screw these up when I migrate to Amazon later in the year). Is there anything that I'm missing here, or does anyone have better suggestions for the approach?

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  • Stop Visual Studio from appending numbers to the end of new controls

    - by techturtle
    I am wondering if there is any way to stop Visual Studio 2010 from appending a number to the end of the ID on new controls I create. For example, when I add a new TextBox, I would prefer that it do this: <asp:TextBox ID="TextBox" runat="server"> <asp:TextBox ID="TextBox" runat="server"> <asp:TextBox ID="TextBox" runat="server"> Instead of this: <asp:TextBox ID="TextBox1" runat="server"> <asp:TextBox ID="TextBox2" runat="server"> <asp:TextBox ID="TextBox3" runat="server"> It would make it easier to rename them appropriately, so I don't have to arrow/mouse over and delete the number each time. As I was writing this, the "Questions that may already have your answer" suggested this: How do I prevent Visual Studio from renaming my controls? which admittedly was the biggest part of my annoyance, but that appears to turn off putting in an ID="" field altogether, not just for pasted controls. It would still be helpful to turn off the numbering for new, non-pasted controls and have it not rename pasted ones as well. At the moment I'm working with ASP.NET, but it would be nice if it there was a way to do it for WinForms as well. Before anyone suggests it, I do know that allowing it to append the numbers prevents name conflicts should I not rename them appropriately. However, I would much rather have it fail to compile so I know to fix the issue now (if I forget to name something properly) rather than find random "TextBox1" items lying around in the code later on.

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  • Is MarshalByRefObject special?

    - by Vilx-
    .NET has a thing called remoting where you can pass objects around between separate appdomains or even physical machines. I don't fully understand how the magic is done, hence this question. In remoting there are two base ways of passing objects around - either they can be serialized (converted to a bunch of bytes and the rebuilt at the other end) or they can inherit from MarshalByRefObject, in which case .NET makes some transparent proxies and all method calls are forwarded back to the original instance. This is pretty cool and works like magic. And I don't like magic in programming. Looking at the MarshalByRefObject with the Reflector I don't see anything that would set it apart from any other typical object. Not even a weird internal attribute or anything. So how is the whole transparent proxy thing organized? Can I make such a mechanism myself? Can I make an alternate MyMarshalByRefObject which would not inherit from MarshalByRefObject but would still act the same? Or is MarshalByRefObject receiving some special treatment by the .NET engine itself and the whole remoting feat is non-duplicatable by mere mortals?

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  • Ideas Needed for a Base Code System

    - by Tegan Snyder
    I've developed a PHP web application that is currently in need of a strategic restructuring. Currently when we setup new clients we give them the entire code base on a subdomain of our main domain and create a new table for them in the database. This results in each client having the entire codebase, meaning when we make bug changes, fixes we have to go back and apply them independently across all clients and this is a pain. What I'd like to create is a base code server that holds all the core PHP files. base.domain.com Then all of our clients (client.domain.com) will only need a few files: config.php would have the database connection information. index.php - displays the login box if session non-existant, otherwise it loads baseline code via remote includes to base.domain.com. My question is does my logic seem feasible? How do other people handle similar situations by having a base code? Also.... Is it even possbile to remotely include PHP files from base.domain.com and include them in client.domain.com? Thanks, Tegan

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  • Start with remoting or with WCF

    - by Sheldon
    Hi. I'm just starting with distributed application development. I need to create (all by myself) an enterprise application for document management. That application will run on an intranet (within the firewall, no internet access is required now, BUT is probably that will be later). The application needs to manage images that will be stored within MySQL Server (as blobs) and those images will be then recovered by the app and eventually one or more of them will be converted to PDF. Performance is the most important non-functional requirement. I have a couple of doubts. What do you suggest to use, .NET Remoting or WCF over TCP-IP (I think second one is the best for the moment I need to expose the business logic over internet, changing the protocol). Where do you suggest to make the transformation of the images to pdf files, I'm using iText. (I have thought to have the business logic stored within the IIS and exposed via WCF, and that business logic to be responsible of getting the images and transforming them to PDF, that because the IIS and the MySQL Server are the same physical machine). I ask about where to do the transformation because the app must be accessible from multiple devices, and for example, for mobile devices, the pdf maybe is not necessary. Thank you very much in advance.

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  • Resource placement (optimal strategy)

    - by blackened
    I know that this is not exactly the right place to ask this question, but maybe a wise guy comes across and has the solution. I'm trying to write a computer game and I need an algorithm to solve this question: The game is played between 2 players. Each side has 1.000 dollars. There are three "boxes" and each player writes down the amount of money he is going to place into those boxes. Then these amounts are compared. Whoever placed more money in a box scores 1 point (if draw half point each). Whoever scores more points wins his opponents 1.000 dollars. Example game: Player A: [500, 500, 0] Player B: [333, 333, 334] Player A wins because he won Box A and Box B (but lost Box C). Question: What is the optimal strategy to place the money? I have more questions to ask (algorithm related, not math related) but I need to know the answer to this one first. Update (1): After some more research I've learned that these type of problems/games are called Colonel Blotto Games. I did my best and found few (highly technical) documents on the subject. Cutting it short, the problem I have (as described above) is called simple Blotto Game (only three battlefields with symmetric resources). The difficult ones are the ones with, say, 10+ battle fields with non-symmetric resources. All the documents I've read say that the simple Blotto game is easy to solve. The thing is, none of them actually say what that "easy" solution is.

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  • RegEx: difference between "(?:...) and normal parentheses

    - by N0thing
    >>> re.findall(r"(?:do|re|mi)+", "mimi") ['mimi'] >>> re.findall(r"(do|re|mi)+", "mimi") ['mi'] According to my understanding of the definitions, it should produce the same answer. The only difference between (...) and (?:...) should be whether or not we can use back-references later. Am I missing something? (...) Matches whatever regular expression is inside the parentheses, and indicates the start and end of a group; the contents of a group can be retrieved after a match has been performed, and can be matched later in the string with the \number special sequence, described below. To match the literals '(' or ')', use ( or ), or enclose them inside a character class: [(] [)]. (?:...) A non-capturing version of regular parentheses. Matches whatever regular expression is inside the parentheses, but the substring matched by the group cannot be retrieved after performing a match or referenced later in the pattern.

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  • How to maintain form state after Post-Redirect-Get in ASP.net?

    - by Ian Boyd
    Imagine a page with a form input: Search Criteria: crackers                   From: [email protected]           To: [email protected]       Subject: How to maintain form state with PRG? Message: Imagine a page with form input:                         Send After the user clicks Send, the server will instruct to client to Redirect, as part of the Post-Redirect-Get pattern. POST /mail/u/compose HTTP/1.1 303 See Other Location: http://stackoverflow.com/mail/u/compose And the client will issue a GET of the new page. The problem is that some elements of the existing form are lost: Search Criteria:                    It gets worse when there are a few drop-downs, and checkboxes. How can i maintain form state in using Post-Redirect-Get in ASP.net, given that the viewstate is then non-existent. Bonus Reading ASP.NET: How to redirect, prefilling form data?

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  • Splitting a set of object into several subsets of 'similar' objects

    - by doublep
    Suppose I have a set of objects, S. There is an algorithm f that, given a set S builds certain data structure D on it: f(S) = D. If S is large and/or contains vastly different objects, D becomes large, to the point of being unusable (i.e. not fitting in allotted memory). To overcome this, I split S into several non-intersecting subsets: S = S1 + S2 + ... + Sn and build Di for each subset. Using n structures is less efficient than using one, but at least this way I can fit into memory constraints. Since size of f(S) grows faster than S itself, combined size of Di is much less than size of D. However, it is still desirable to reduce n, i.e. the number of subsets; or reduce the combined size of Di. For this, I need to split S in such a way that each Si contains "similar" objects, because then f will produce a smaller output structure if input objects are "similar enough" to each other. The problems is that while "similarity" of objects in S and size of f(S) do correlate, there is no way to compute the latter other than just evaluating f(S), and f is not quite fast. Algorithm I have currently is to iteratively add each next object from S into one of Si, so that this results in the least possible (at this stage) increase in combined Di size: for x in S: i = such i that size(f(Si + {x})) - size(f(Si)) is min Si = Si + {x} This gives practically useful results, but certainly pretty far from optimum (i.e. the minimal possible combined size). Also, this is slow. To speed up somewhat, I compute size(f(Si + {x})) - size(f(Si)) only for those i where x is "similar enough" to objects already in Si. Is there any standard approach to such kinds of problems? I know of branch and bounds algorithm family, but it cannot be applied here because it would be prohibitively slow. My guess is that it is simply not possible to compute optimal distribution of S into Si in reasonable time. But is there some common iteratively improving algorithm?

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  • C programming - How to print numbers with a decimal component using only loops?

    - by californiagrown
    I'm currently taking a basic intro to C programming class, and for our current assignment I am to write a program to convert the number of kilometers to miles using loops--no if-else, switch statements, or any other construct we haven't learned yet are allowed. So basically we can only use loops and some operators. The program will generate three identical tables (starting from 1 kilometer through the input value) for one number input using the while loop for the first set of calculations, the for loop for the second, and the do loop for the third. I've written the entire program, however I'm having a bit of a problem with getting it to recognize an input with a decimal component. Here is what I have for the while loop conversions: #include <stdio.h> #define KM_TO_MILE .62 main (void) { double km, mi, count; printf ("This program converts kilometers to miles.\n"); do { printf ("\nEnter a positive non-zero number"); printf (" of kilometers of the race: "); scanf ("%lf", &km); getchar(); }while (km <= 1); printf ("\n KILOMETERS MILES (while loop)\n"); printf (" ========== =====\n"); count = 1; while (count <= km) { mi = KM_TO_MILE * count; printf ("%8.3lf %14.3lf\n", count, mi); ++count; } getchar(); } The code reads in and converts integers fine, but because the increment only increases by 1 it won't print a number with a decimal component (e.g. 3.2, 22.6, etc.). Can someone point me in the right direction on this? I'd really appreciate any help! :)

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  • BackOffice Database Application FrontEnd - Program in C#/VB.Net or PHP?

    - by HK1
    I'm working on a project where there will be a MySQL database containing data that will mostly be displayed on the web using PHP. However, there is a need here for a back-office data entry application (linked to the same MySQL database) that is feature rich and easy to use. what I'm trying to understand is where we are at with web-based frontends. I find that there are still so many events and features that I can make use of in a Windows Desktop GUI written in something like C#, VB.Net or MS Access. I don't have a lot of experience programming UI for web but it's my impression that it's still more difficult and takes longer to get similar or the same functionality using non-MS web technologies (I dislike ASP.net, sorry) as compared to programming the desktop portion in a traditional desktop application language like C#, VB.Net, or MS Access. jQuery and jQuery UI are definately making things easier. Also, there's very rich online applications like Google Docs and Zoho but it's my impression that these are programmed by some of the top web UI programmers around, not to mention that it takes longer to write it and intensive testing to make it work in all of your target browsers. It also takes extra time and code to "block" browsers that don't meet the requirements. What programming language would you recommend? I know I may not have given enough information here but I'm not sure what I'm missing. If you have questions just leave a comment below so I can edit this post and answer the questions.

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  • Storing strings from a text file/scanner. Array or built-in?

    - by Flowdorio
    This code snippet is to to read a text file, turn the lines into objects through a different public (non changeable) class(externalClass). The external class does nothing but turn strings (lines from the .txt through nextLine) into objects, and is fully functional. The scanner(scanner3) is assigned to the text file. while (scanner3.hasNext()) { externalClass convertedlines = new externalClass(scanner3.nextLine()); I'm not new to programming, but as I'm new to java, I do not know if this requires me to create an array, or if the returned objects are sorted in some other way. i.e is the "importedlines" getting overwritten with each run of the loop(and I need to introduce an array into the loop), or are the objects stored in some way? The question may seem strange, but with the program I am making it would be harder (but definitely not impossible) if I used an array. Any help would be appreciated. As requested, externalClass: public class exernalClass { private String line; externalClass(String inLine){ line = inLine; } public String giveLine() { return line; } }

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  • WPF tree data binding model & repository

    - by Am
    Hi, I have a well defined tree repository. Where I can rename items, move them up, down, etc. Add new and delete. The data is stored in a table as follows: Index Parent Label Left Right 1 0 root 1 14 2 1 food 2 7 3 2 cake 3 4 4 2 pie 5 6 5 1 flowers 8 13 6 5 roses 9 10 7 5 violets 11 12 Representing the following tree: (1) root (14) (2) food (7) (8) flowers (13) (3) cake (4) (5) pie (6) (9) roeses (10) (11) violets (12) or root food cake pie flowers roses violets Now, my problem is how to represent this in a bindable way, so that a TreeView can handle all the possible data changes? Renaming is easy, all I need is to make the label an updatble field. But what if a user moves flowers above food? I can make the relevant data changes, but they cause a complete data change to all other items in the tree. And all the examples I found of bindable hierarchies are good for non static trees.. So my current (and bad) solution is to reload the displayed tree after relocation change. Any direction will be good. Thanks

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  • GPG error occurs while using "deb file:/local-path-to-repo ..." in /etc/apt/sources.list

    - by Chandler.Huang
    I need to install packages within non-internet connection environment. My plan is to download dist structure from Internet and then add file path to /etc/apt/sources.list. So I download related structure includes ubunt/dists/precise, precise-backports, precise-proposed, precise-security, precise-updates from a ftp mirror server. And then I remove original source and add the following to my /etc/apt/sources.list. deb file:path-to-local-ubuntu-directory/ precise main restricted multiverse universe deb-src file:path-to-local-ubuntu-directory/ precise main restricted multiverse universe Then I got GPG error as following after apt-get update. root@openstack:/~# apt-get update Ign file: precise InRelease Get:1 file: precise Release.gpg [198 B] Get:2 file: precise Release [50.1 kB] Ign file: precise Release Get:3 file: precise/main TranslationIndex [3,761 B] Get:4 file: precise/multiverse TranslationIndex [2,716 B] Get:5 file: precise/restricted TranslationIndex [2,636 B] Get:6 file: precise/universe TranslationIndex [2,965 B] Reading package lists... Done W: GPG error: file: precise Release: The following signatures were invalid: BADSIG 0976EAF437D05B5 Ubuntu Archive Automatic Signing Key <[email protected]> I had tried use the following steps after google but in vain. sudo apt-get clean cd /var/lib/apt sudo mv lists lists.old sudo mkdir -p lists/partial sudo apt-get update Is there any way to resolve this? And why this error occurs? Thanks a lot.

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  • Getting a gestureoverlayview

    - by Codejoy
    I have been using some nice tutorials on drawing graphics on my android. I wanted to also add in the cool gesture demo found here: http://developer.android.com/resources/articles/gestures.html That takes these lines of code: GestureOverlayView gestures = (GestureOverlayView) findViewById(R.id.gestures); gestures.addOnGesturePerformedListener(this); This is fine and dandy yet I realize in my demo i'm trying to build using code from "Playing with Graphics in Android". The demos make sense, everything makes sense but I found out by using: setContentView(new Panel(this)); as is required by the Playing With Graphics tutorials, then the findViewById seems to no longer be valid and returns null. At first I was about to post a stupider question as to why this is happening, a quick test of playing with the setContentView made me realize the cause of findViewById returning null, I just do not know how to remedy this issue. Whats the key I am missing here? I realize that the new Panel is doinking some reference up but I am not sure how to make the connection here. The: R.id.gestures is defined right int he main.xml as: (just like the tutorial) <android.gesture.GestureOverlayView android:id="@+id/gestures" android:layout_width="fill_parent" android:layout_height="0dip" android:layout_weight="1.0" /> So I did confirm the setContentView(new Panel(this)) is causing the issue. So I know the issue is that I have to figure out how to add the android.gesture.GestureOverlayView to the panel class somehow, I am just not sure how to go about this. After fighting with this I generally know what I need to do just now how to do it. I think I need either the equivalent of creating a panel in that main.xml OR figuring out how to build whats in main.xml for the gestures in code. I am close because I did this: GestureOverlayView gestures = new GestureOverlayView(this); which gets me a non null gestures now, unfortunately since I am not telling it to fill Parent anywhere I don't think its really showing up, so I am trying hard to figure out layout pa rams. Am I even on the right track?

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  • Concise description of how .h and .m files interact in objective c?

    - by RJ86
    I have just started learning objective C and am really confused how the .h and .m files interact with each other. This simple program has 3 files: Fraction.h #import <Foundation/NSObject.h> @interface Fraction : NSObject { int numerator; int denominator; } - (void) print; - (void) setNumerator: (int) n; - (void) setDenominator: (int) d; - (int) numerator; - (int) denominator; @end Fraction.m #import "Fraction.h" #import <stdio.h> @implementation Fraction -(void) print { printf( "%i/%i", numerator, denominator ); } -(void) setNumerator: (int) n { numerator = n; } -(void) setDenominator: (int) d { denominator = d; } -(int) denominator { return denominator; } -(int) numerator { return numerator; } @end Main.m #import <stdio.h> #import "Fraction.h" int main(int argc, char *argv[]) { Fraction *frac = [[Fraction alloc] init]; [frac setNumerator: 1]; [frac setDenominator: 3]; printf( "The fraction is: " ); [frac print]; printf( "\n" ); [frac release]; return 0; } From what I understand, the program initially starts running the main.m file. I understand the basic C concepts but this whole "class" and "instance" stuff is really confusing. In the Fraction.h file the @interface is defining numerator and denominator as an integer, but what else is it doing below with the (void)? and what is the purpose of re-defining below? I am also quite confused as to what is happening with the (void) and (int) portions of the Fraction.m and how all of this is brought together in the main.m file. I guess what I am trying to say is that this seems like a fairly easy program to learn how the different portions work with each other - could anyone explain in non-tech jargon?

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  • Is it necessary to var scope loop variables in CFScript?

    - by Mel
    When using CFML and CF9 I usually var scope my loop variables; in this case local.i, for example: <cfloop list="#this.list#" index="local.i"> <cfif Len(local.i) GT 10> // do something </cfif> </cfloop> I recently started converting some stuff into CFScript, and (to my disappointment I found out that there is no way to loop over a list in CFScript) I'm wondering if I should still var scope my loop variables, and how: for (i = 1; LTE ListLen(this.list); i = i + 1 ) { if (Len(ListGetAt(this.list, i) GT 10)) { // do something } } Should I be doing local.i = 1 and local.i = local.i + 1 istead of the sample code in my example? Is it necessary? EDIT: I should also ask if the CFScript form of my CFML loop is correct; I ask because I just noticed that my CFML loop uses a , (comma and space) for the delimiter argument, which seems non-existence in the CFScript version of the loop.

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  • Will a Ph. D. in Computer Science help?

    - by Francisco Garcia
    I am close to my 30s and still learning about programming and software engineering. Like most people who like their profession I truly believe that I should aim to improve and keep updated. One of the things I do is reading technical papers from professional publications (IEEE and ACM) but I admit there are very good bloggers out there too. Lately I started to think (should I say realize?) that Ph. D people actually are expected to expand constantly their knowledge, but little is expected from lower classes once they know enough This made me think that maybe having a Ph. D will help to have more... respect? but I also believe that I am already getting old for that. Futhermore I see many master and doctor programs that does not seem to add any value over hard experience and self learning. I belive that a degree in computer science, althought not necessary, can lay out a good base for programming work. However: What can a Ph. D. degree give you that you cannot learn on your own? (if you are not into something VERY specific and want to work in a non academic environment)

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  • Using items in a list as arguments

    - by Travis Brown
    Suppose I have a function with the following type signature: g :: a -> a -> a -> b I also have a list of as—let's call it xs—that I know will contain at least three items. I'd like to apply g to the first three items of xs. I know I could define a combinator like the following: ($$$) :: (a -> a -> a -> b) -> [a] -> b f $$$ (x:y:z:_) = f x y z Then I could just use g $$$ xs. This makes $$$ a bit like uncurry, but for a function with three arguments of the same type and a list instead of a tuple. Is there a way to do this idiomatically using standard combinators? Or rather, what's the most idiomatic way to do this in Haskell? I thought trying pointfree on a non-infix version of $$$ might give me some idea of where to start, but the output was an abomination with 10 flips, a handful of heads and tails and aps, and 28 parentheses. (NB: I know this isn't a terribly Haskelly thing to do in the first place, but I've come across a couple of situations where it seems like a reasonable solution, especially when using Parsec. I'll certainly accept "don't ever do this in real code" if that's the best answer, but I'd prefer to see some clever trick involving the ((->) r) monad or whatever.)

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  • Multiple exports with MEF does some really heinous stuff -- why, and why is it allowed?

    - by Dave
    I have an interesting situation where I need to do something like this: [Export[typeof(ICandy1)] [Export[typeof(ICandy2)] public class Candy : ICandy2 { ... } where public interface ICandy1 { ... } public interface ICandy2 : ICandy1 { ... } I couldn't find any posts anywhere regarding using multiple [Export] attributes, so I figured, what the hell, might as well try it. At first glance, it actually seemed to work. I have a couple of methods that call into both interfaces of a Candy instance, and it was fine. However, as I started to test the app, I saw that the behavior wasn't right, and when looking at the Output window, I saw that I was getting tons of COMExceptions. I couldn't track down where they were all coming from, but they always occurred when a worker thread was sleeping. I figured that it had to be from the main thread, then, but didn't know how to debug this at all. Nothing should have been going on in the GUI, and I disabled my DispatchTimers just in case -- same thing. Even more strange than the COMExceptions was the really, really erratic behavior when stepping through code. About 30% of the time, when I single stepped, it would pop out of the method, or it would single step over two lines of code! Totally weird stuff that I am not used to seeing. The only thing that changed between working and non-working code was the introduction of MEF through my plugin loading code. So as a test, I changed my plugin assembly to only export one interface, and I hardcoded everything in the app that relied on the other (now not-implemented) interface. And now the COMExceptions are gone, and the weird debugging behavior is gone. Is this something people here have seen before? If MEF is not expected to allow a class to Export multiple interfaces, then shouldn't a CompositionException get raised when composing the parts? Can anyone explain why MEF would cause these weird problems???

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