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• How to use iPhone OS 3.2 functionality in an iPhone OS 3.0 app?

  - by mystify

  Problem: My app must run on iPhone OS 3.0. However, there are some features of iPhone OS 3.2 which I really want to use. Just as a little add-on for free. But I don't want to cut off my user base by doing this. Imagine you're an iPhone OS 3.0 thing, and someone gives you a book to read. It has iPhone OS 3.2 instructions. You never learned those. So what do you do? Crash? They would have to be hidden, so you're not bothered. Someone wrote recently on SO: keep in mind that you have to check the version at places in the source code where you like to use the new features and provide alternatives for older os versions So how could I do that? Wouldn't Xcode throw warnings when it finds stuff that isn't linkable from anything anywhere? Would I just check for the OS version and dynamically link - somehow - to whatever stuff I think is cool?

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• java class that simulates a simple database table

  - by ericso

  I have a collection of heterogenous data that I pull from a database table mtable. Then, for every unique value uv in column A, I compute a function of (SELECT * FROM mtable WHERE A=uv). Then I do the same for column B, and column C. There are rather a lot of unique values, so I don't want to hit the db repeatedly - I would rather have a class that replicates some of the functionality (most importantly some version of SELECT WHERE). Additionally, I would like to abstract the column names away from the class definition, if that makes any sense - the constructor should take a list of names as a parameter, and also, I suppose, a list of types (right now this is just a String[], which seems hacky). I'm getting the initial data from a RowSet. I've more or less done this by using a hashmap that maps Strings to lists/arrays of Objects, but I keep getting bogged down in comparisons and types, and am thinking that my current implementation really isn't as clean and clear as it could be. I'm pretty new to java, also, and am not sure if I'm not going down a completely incorrect path. Does anyone have any suggestions?

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• Maximum length of a std::basic_string<_CharT> string

  - by themoondothshine

  Hey all, I was wondering how one can fix an upper limit for the length of a string (in C++) for a given platform. I scrutinized a lot of libraries, and most of them define it arbitrarily. The GNU C++ STL (the one with experimental C++0x features) has quite a definition: size_t npos = size_t(-1); /*!< The maximum value that can be stored in a variable of type size_t */ size_t _S_max_len = ((npos - sizeof(_Rep_base))/sizeof(_CharT) - 1) / 4; /*!< Where _CharT is a template parameter; _Rep_base is a structure which encapsulates the allocated memory */ Here's how I understand the formula: The size_t type must hold the count of units allocated to the string (where each unit is of type _CharT) Theoretically, the maximum value that a variable of type size_t can take on is the total number of units of 1 byte (ie, of type char) that may be allocated The previous value minus the overhead required to keep track of the allocated memory (_Rep_base) is therefore the maximum number of units in a string. Divide this value by sizeof(_CharT) as _CharT may require more than a byte Subtract 1 from the previous value to account for a terminating character Finally, that leave the division by 4. I have absolutely no idea why! I looked at a lot of places for an explanation, but couldn't find a satisfactory one anywhere (that's why I've been trying to make up something for it! Please correct me if I'm wrong!!).

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• How to make html-files with content to be used in a simple ajax site to behave nicely in google?

  - by metatron

  I made some ajax sites in the past where I used ajax to get more of a desktop application feeling for my sites and also to keep the site maintainable. My strategy was making one index page and from there pulling in html content from some subpages. (So far I didn't use ajax to send data to the server.) The problem that I ran into is this: I want the subpages to be readable by google since they contain valuable content but once they show up in google's results they lead to the naked html-file (no css nor Javascript). I solved this by putting a javascript redirect (window.location = ...) on the subpages so they lead to the correct page. So as an example let's say I have a site at example.com with some javascript and css and a naked content page that should be loaded via ajax: example.com/content.html. Via ajax I pull in what I need from the content file but since my index.html contains href's to the content.html file (I want the content of my ajax site to be readable without Javascript) it will be indexed by google and gets listed in the search results. But I don't want people to see the naked html file. Hence the redirect that goes to the index page and gets handled by some Javascript to show the content as I want it to be showed. I was wondering if there are nicer solutions to this problem or different approaches.

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• session_set_cookie_params on multi-domain sites

  - by nillls

  Hi! I'm currently developing for an application (www.domain.se, .eu) where we're experiencing problems with sessions not propagating across domains. Internet Explorer is the root cause of this, as it will differentiate sessions depending on whether we're typing in "domain.se" or "www.domain.se". Due to some unfortunate redirecting, we're not able to keep the user on the same address the user typed in, instead we're always redirecting to www.domain.se on login. Needless to say, IE users can not login when typing "domain.se". To make this error go away, we implemented a function to try and set the session to be valid across all possible domains by doing the following: if($_SERVER['HTTP_HOST'] == "domain.se") { session_set_cookie_params(3600, '/', '.domain.se', true); } There are basically a few if:s that we go through depending on what address the user typed in, but the third argument stays the same. This, however, results in no-one being able to log in, regardless of domain. I've tried reading up on how session_set_cookie_params() works but to no avail. Any help is greatly appreciated!

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• PHP date/time help/

  - by NOW

  I keep getting a value of 0 for $years and $months when there should be a value other then 0 can someone tell me what I'm doing wrong with my code? And what I need to fix? I'm trying to subtract two dates. Here is my PHP code. $delete_date = "2000-01-12 08:02:39"; $current_date = date('Y-m-d H:i:s'); //current date $diff = abs(strtotime($current_date) - strtotime($delete_date)); $years = floor($diff / (365*60*60*24)); $months = floor(($diff - $years * 365*60*60*24) / (30*60*60*24)); echo $current_date . '<br />'; echo $delete_date. '<br />'; echo $diff. '<br />'; echo $years. '<br />'; echo $months. '<br />';

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• Data base design with Blob

  - by mmuthu

  Hi, I have a situation where i need to store the binary data into database as blob column. There are three different table exists in my database where in i need to store a blob data for each record. Not every record will have the blob data all the time. It is time and user based. The table one will have to store the *.doc files almost for all the record The table two will have to store the *.xml optionally. The table three will have to store images (not sure what is frequency, etc) Now my questions is whether it is a good idea to maintain a separate table to store the blob data pointing it to the respective table PK's (Yes, there will be no FK's and assuming program will maintain it). It will be some thing like below, BLOB|PK_ID|TABLE_NAME Alternatively, is it a good idea to keep the blob column in respective tables. As for as my application runtime is concerned, The table 2 will be read very frequently. Though the blob column will not be required. The table 2 record will gets deleted frequently. Similarly other blob data in respective table will not be accessed frequently. All of the blob content will be read on-demand basis. I'm thinking first approach will work better for me. What do you guys think? Btw, I'm using Oracle.

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• CodeIgniter subfolders and URI routing

  - by shummel7845

  I’ve read the manual on URI routing and views and something is not clicking with me. In my views folder, I have a subfolder called products. In there is a file called product_view. In my controller, I have: function index() { $data['title'] = 'Product Overview'; $data['main_content'] = 'products/product_view'; $this->load->view('templates/main.php', $data); } The template loads a header view, a footer view and a navigation view, plus the view as a main content variable. In my URI routing, I have: $route['products/product-overview'] = 'products/product_view']; This causes a 404 error when I try to go to domain.com/products/product-overview. Do I need to do something with my .htaccess? If so, what? Here is my .htaccess: Options +FollowSymLinks Options -Indexes DirectoryIndex index.php RewriteEngine on RewriteCond $1 !^(index\.php|resources|images|css|js|robots\.txt|favicon\.ico) RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^(.*)$ index.php?/$1 [L,QSA] I’d appreciate some specific help, as the documentation isn’t specific on how to address this. I’ve done a little searching in the forums, and didn’t see anything, but I’m posting this while I keep looking.

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• What are the potential problems with exposing the Facebook API secret?

  - by genehack

  I'm writing a little web utility that posts status updates to Twitter and/or Facebook. That involved creating 'applications' with both those services in order to get API keys and 'secrets'. My question is how protected I really need to keep those secrets -- in order for this to work at all, you seem to need the secret to interact with the authentication part of the service to grant the app access to your account and/or grant it permission to post updates on your behalf. Facebook's documentation says to protect the secret, but at least one other Facebook utility distributes the API key and secret in the source. It's important to note: this isn't your standard Facebook 'application' that runs within the context of Facebook, nor is it a standard "desktop"-style compiled app -- it's a web-based application intended to be run on your own web server. The audience for this is probably small and somewhat more sophisticated than average -- so, one technical alternative would be to require people to obtain their own API key and secret to use the app. That seems like a lot of work, however, and a fairly large barrier to entry to anybody using this. Anybody know or have any insight on what sort of trouble I'm letting myself in for if I put both the secrets and the API keys in the config for my app and check it into Github for all the world to see?

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• Write a completely fluid HTML page (using '%' instead of 'px' for EVERY element height/width)

  - by barak manos

  I am designing my HTML pages to be completely fluid: For every element in the mark-up (HTML), I am using 'style="height:%;width:%"' (instead of 'style="height:*px;width:*px"'). This approach seems to work pretty well, except for when changing the window measurements, in which case, the web page elements change their position and end up "on top of each other". I have come up with a pretty good run-time (java-script) solution to that: var elements = document.getElementsByTagName("*"); for (var i=0; i < elements.length; i++) { if (elements[i].style.height) elements[i].style.height = elements[i].offsetHeight+"px"; if (elements[i].style.width ) elements[i].style.width = elements[i].offsetWidth +"px"; } The only problem remaining is, that if the user opens up the website by entering the URL into a non-maximized window, then the page fits that portion of the window. Then, when maximizing the window, the page remains in its previous measurements. So in essence, I have solved the initial problem (when changing the window measurements), but only when the window is initially in its maximum size. Any ideas on how to tackle this problem? (given that I would like to keep my "% page-design" as is).

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• Why is this removing all elements from my LinkedList?

  - by Brian

  Why is my remove method removing every element from my Doubly Linked List? If I take out that if/else statements then I can successfully remove middle elements, but elements at the head or tail of the list still remain. However, I added the if/else statements to take care of elements at the head and tail, unfortunately this method now removes every element in my list. What am I do wrong? public void remove(int n) { LinkEntry<E> remove_this = new LinkEntry<E>(); //if nothing comes before remove_this, set the head to equal the element after remove_this if (remove_this.previous == null) head = remove_this.next; //otherwise set the element before remove_this equal to the element after remove_this else remove_this.previous.next = remove_this.next; //if nothing comes after remove_this, set the tail equal to the element before remove_this if (remove_this.next == null) tail = remove_this.previous; //otherwise set the next element's previous pointer to the element before remove_this else remove_this.next.previous = remove_this.previous; //if remove_this is located in the middle of the list, enter this loop until it is //found, then remove it, closing the gap afterwards. int i = 0; for (remove_this = head; remove_this != null; remove_this = remove_this.next) { //if i == n, stop and delete 'remove_this' from the list if (i == n) { //set the previous element's next to the element that comes after remove_this remove_this.previous.next = remove_this.next; //set the element after remove_this' previous pointer to the element before remove_this remove_this.next.previous = remove_this.previous; break; } //if i != n, keep iterating through the list i++; } }

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• Doing a global count of an object type (like Users), best practice?

  - by user246114

  Hi, I know keeping global counters is frowned upon in app engine. I am interested in getting some stats though, like once every 24 hours. For example, I'd like to count the number of User objects in the system once every 24 hours. So how do we do this? Do we simply keep a set of admin tool functions which do something like: SELECT FROM com.me.project.server.User; and just see what the size of the returned List is? This is kind of a bummer because the datastore would have to deserialize every single User instance to create the returned list, right? I could optimize this possibly by asking for only the keys to be returned, so the whole User object doesn't have to be deserialized. Then again, a global counter for # of users probably would create too much contention, because there probably won't be hundreds of signups a minute for the service I'm creating. How should we go about doing this? Getting my total number of users once a day is probably a pretty typical operation? Thank you

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• java.awt -- when java outputs an image to my monitor (screen), where is the file that is output to the monitor card?

  - by user1405870

  Suppose that I am drawing a set of images using java graphics objects. Suppose that I java is outputting these images to my monitor. Where is the file or files that are sent to the monitor card (the graphical representation files). How can I take this file and save it to disk, or how can I take this file and write it to an array, or how can I take these files and combine the results of their output (to the monitor) into a single file for saving? I don't want to use a screen shot feature, I want to be able to redirect (xor capture also) the output to the monitor to some sort of byte-stream. I note that monitors are much better than semaphores, when you are talking about display capabilities; I don't need a counter example. I might not be asking the correct question. It might be that I want to capture the file while it is still in User Space, before it is put into 'Device Space'. I would like to try and capture the byte stream so that I can convert it to MPEG-4 format. I either need a streaming output from the MPEG-4 converter, coming from the streaming input, or else, I need to take static images at discrete times and convert the images. What format will the output from User Space be in? What format will the Device Space output be in? Try to keep speculation to a minimum. http://docs.oracle.com/javame/config/cdc/opt-pkgs/api/jsr927/index.html I guess that Java has made a means of displaying AWT objects on a television screen. Thank you. Ryan Zoerner

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• Winlibre - An Aptitude-Synaptic for Windows. Would that be useful?

  - by acadavid

  Hi everyone. Last year, in 2009 GSoC, I participated with an organization called Winlibre. The basic idea is having a project similar to Aptitude (or Apt-get) and a GUI like Synaptic but for Windows and just to hold (initially), only open source software. The project was just ok, we finished what we considered was a good starting point but unfortunately, due to different occupations of the developers, the project has been idle almost since GSoC finished. Now, I have some energy, time and interest to try to continue this development. The project was divided in 3 parts: A repository server (which i worked on, and which was going to store and serve packages and files), a package creator for developers, and the main app, which is apt-get and its GUI. I have been thinking about the project, and the first question that came to my mind is.. actually is this project useful for developers and Windows users? Keep in mind that the idea is to solve dependencies problems, and install packages "cleanly". I'm not a Windows developer and just a casual user, so i really don't have a lot of experience on how things are handled there, but as far as I have seen, all installers handle those dependencies. Will windows developers be willing to switch from installers to a packages way of handling installations of Open source Software? Or it's just ok to create packages for already existing installers? The packages concept is basically the same as .deb or .rpm files. I still have some other questions, but basically i would like to make sure that it's useful in someway to users and Windows developers, and if developers would find this project interesting. If you have any questions, feedback, suggestions or criticisms, please don't mind about posting them. Thanks!!

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• android service using SystemClock.elapsedRealTime() instead of SystemClock.uptimeMillis() works in emulator but not in samsung captivate ?

  - by Aleadam

  First question here in stackoverflow :) I'm running a little android 2.2 app to log cpu frequency usage. It is set up as a service that will write the data every 10 seconds using a new thread. The code for that part is very basic (see below). It works fine, except that it would not keep track of time while the phone is asleep (which, I know, is the expected behavior). Thus, I changed the code to use SystemClock.elapsedRealTime() instead. Problem is, in emulator both commands are equivalent, but in the phone the app will start the thread but it will never execute the mHandler.postAtTime command. Any advice regarding why this is happening or how to overcome the issue is greatly appreciated. PS: stopLog() is not being called. That's not the problem. mUpdateTimeTask = new Runnable() { public void run() { long millis = SystemClock.uptimeMillis() - mStartTime; int seconds = (int) (millis / 1000); int minutes = seconds / 60; seconds = seconds % 60; String freq = readCPU (); if (freq == null) Toast.makeText(CPU_log_Service.this, "CPU frequency is unreadable.\nPlease make sure the file has read rights.", Toast.LENGTH_LONG).show(); String str = new String ((minutes*60 + seconds) + ", " + freq + "\n"); if (!writeLog (str)) stopLog(); mHandler.postAtTime(this, mStartTime + (((minutes * 60) + seconds + 10) * 1000)); }}; mStartTime = SystemClock.uptimeMillis(); mHandler.removeCallbacks(mUpdateTimeTask); mHandler.postDelayed(mUpdateTimeTask, 100);

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• Standalone Calendar App/Software

  - by Hewittnbut

  We're looking for a standalone (non-cms) calendaring solution to display on the web. It could be open source or a paid service. We're primarily looking for a way to display a calendar on the web complete with when the events are and what the names of the events are. It would be great if it can display in different views like by week, month, year. Month view would be the most important one. We want to keep it as simple as possible. We mainly just want users to view the calendar. The events do not even have to be editable on the end user's side just as long as there is some way for us on the backend to add/delete/import events into the calendar whether it be through .ics (iCal files)/desktop software/via some web interface. We know Google Calendar is around and there is also PHPiCalendar. Are there any other alternatives around? Any suggestions would be appreciated! Thanks!

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• How do I create a self referential association (self join) in a single class using ActiveRecord in Rails?

  - by Daniel Chang

  I am trying to create a self join table that represents a list of customers who can refer each other (perhaps to a product or a program). I am trying to limit my model to just one class, "Customer". The schema is: create_table "customers", force: true do |t| t.string "name" t.integer "referring_customer_id" t.datetime "created_at" t.datetime "updated_at" end add_index "customers", ["referring_customer_id"], name: "index_customers_on_referring_customer_id" My model is: class Customer < ActiveRecord::Base has_many :referrals, class_name: "Customer", foreign_key: "referring_customer_id", conditions: {:referring_customer_id => :id} belongs_to :referring_customer, class_name: "Customer", foreign_key: "referring_customer_id" end I have no problem accessing a customer's referring_customer: @customer.referring_customer.name ... returns the name of the customer that referred @customer. However, I keep getting an empty array when accessing referrals: @customer.referrals ... returns []. I ran binding.pry to see what SQL was being run, given a customer who has a "referer" and should have several referrals. This is the SQL being executed. Customer Load (0.3ms) SELECT "customers".* FROM "customers" WHERE "customers"."id" = ? ORDER BY "customers"."id" ASC LIMIT 1 [["id", 2]] Customer Exists (0.2ms) SELECT 1 AS one FROM "customers" WHERE "customers"."referring_customer_id" = ? AND "customers"."referring_customer_id" = 'id' LIMIT 1 [["referring_customer_id", 3]] I'm a bit lost and am unsure where my problem lies. I don't think my query is correct -- @customer.referrals should return an array of all the referrals, which are the customers who have @customer.id as their referring_customer_id.

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• strange doctrine update problem

  - by larryzhao

  Hi, guys, I have a simple table like following: class SnookerCurrentInfo extends Doctrine_Record { public function setTableDefinition() { $this->hasColumn('current_frame_id', 'integer', 4, array('notnull' => 'false')); $this->hasColumn('current_player_id', 'integer', 4, array('notnull' => 'false')); $this->hasColumn('current_score1', 'integer', 4, array('notnull' => 'false')); $this->hasColumn('current_score2', 'integer', 4, array('notnull' => 'false')); } public function setUp(){ $this->setTableName('snooker_current_info'); } } and I would like to keep only one entry in this table. So every time the value is changed I read the entry with id = 1 out and change the object and execute save. like the following: $info = Doctrine::getTable('SnookerCurrentInfo')->find(1); $info->current_frame_id = $jsonInfo['current_frame_id']; $info->current_player_id = $jsonInfo['current_player_id']; $info->current_score1 = $jsonInfo['current_score1']; $info->current_score2 = $jsonInfo['current_score2']; $info->save(); but the strange thing is, I try to make it clear. Let's say at first, the entry is (30, 1, 1, 0) and I switch player, so update the entry to (30, 2, 1, 0). and I switch the player back again, so the entry should be updated to (30, 1, 1, 0), but this is not affected to the database!! In the database, the entry still remains as (30, 2, 1, 0)!!!! But if after (30, 2, 1, 0), I update the score to (30, 2, 1, 1) and then switch the player back (30, 1, 1, 1) then this is ok. What's that? How should I deal with it? Thanks for a lot helping, really urgent!!

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• Program that edits string and prints each word individually with C

  - by Michael_19

  I keep getting the error segmentation fault (core dumped) when I run my progam. #include<stdio.h> #include<stdlib.h> int nextword(char *str); int main(void) { char str[] = "Hello! Today is a beautiful day!!\t\n"; int i = nextword(str); while(i != -1) { printf("%s\n",&(str[i])); i = nextword(NULL); } return 0; } int nextword(char *str) { // create two static variables - these stay around across calls static char *s; static int nextindex; int thisindex; // reset the static variables if (str != NULL) { s = str; thisindex = 0; // TODO: advance this index past any leading spaces while (s[thisindex]=='\n' || s[thisindex]=='\t' || s[thisindex]==' ' ) thisindex++; } else { // set the return value to be the nextindex thisindex = nextindex; } // if we aren't done with the string... if (thisindex != -1) { nextindex = thisindex; // TODO: two things // 1: place a '\0' after the current word // 2: advance nextindex to the beginning // of the next word while (s[nextindex] != ' ' && s[nextindex] != '\0') nextindex++; str[nextindex] = '\0'; nextindex++; } return thisindex; } The goal of the program is to print each word in the string str[] to the console on a new line. I am a beginning programmer and this is an assignment so I must use this type of format (no string library allowed). I just would like to know where I went wrong and how I can fix it.

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• Rails Form Submission, User can't be blank

  - by pmanning

  I'm trying to create an event through an event form and I keep getting a form error that says "User can't be blank". The event needs a user_id to post a feed_item showing who created the event. Why can't this event get created? event.rb class Event < ActiveRecord::Base attr_accessible :description, :location, :title, :category_id, :start_date, :start_time, :end_date, :end_time, :image belongs_to :user belongs_to :category has_many :rsvps has_many :users, through: :rsvps, dependent: :destroy mount_uploader :image, ImageUploader validates :title, presence: true, length: { maximum: 60 } validates :user_id, presence: true create_events.rb (database) class CreateEvents < ActiveRecord::Migration def change create_table :events do |t| t.string :title t.date :start_date t.time :start_time t.date :end_date t.time :end_time t.string :location t.string :description t.integer :category_id t.integer :user_id t.timestamps end add_index :events, [:user_id, :created_at] end end events_controller.rb def new @event = Event.new @user = current_user end def create @event = current_user.events.build(params[:event]) if @event.save flash[:success] = "Sesh created!" redirect_to root_url else @feed_items = [] render 'static_pages/home' end end routes.rb SampleApp::Application.routes.draw do resources :users do member do get :following, :followers, :events end end resources :events do member do get :members end end root to: 'static_pages#home' events/new.html.erb <%= form_for @event, :html => {:multipart => true} do |f| %> <%= render 'shared/error_messages', object: @event %>

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• Do Distributed Version Control Systems promote poor backup habits?

  - by John

  In a DVCS, each developer has an entire repository on their workstation, to which they can commit all their changes. Then they can merge their repo with someone else's, or clone it, or whatever (as I understand it, I'm not a DVCS user). To me that flags a side-effect, of being more vulnerable to forgetting to backup. In a traditional centralised system, both you as a developer and the people in charge know that if you commit something, it's held on a central server which can have decent backup solutions in place. But using a DVCS, it seems you only have to push your work to a server when you feel like sharing it. It's all very well you have the repo locally so you can work on your feature branch for a month without bothering anyone, but it means (I think) that checking in your code to the repo is not enough, you have to remember to do regular pushes to a backed-up server. It also means, doesn't it, that a team lead can't see all those nice SVN commit emails to keep a rough idea what's going on in the code-base? Is any of this a real issue?

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• How to detect if a RGB is fully transparent?

  - by omega

  In java, I want to make a fully transparent RGBA, and I do that by using public static int getTransparentRGB() { int r = 0; int g = 0; int b = 0; int a = 0; int new_pixel = (a << 24) | (r << 16) | (g << 8) | b; return new_pixel; } Color color = new Color(getTransparentRGB()); System.out.println(color.getAlpha()); // -> 255 ?! I purposely keep all rgba values 0. However after I create the Color object with the rgba value as the constructor, if I call .getAlpha(), I get 255 even though I made the rgb value with a 0 alpha. If it returns 255, how could I tell the difference between a Color object that wasn't transparent, because that would also have a 255 alpha. I expect the color object to return a 0 alpha based on the function above. Does anyone know whats going on? Thanks

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• Saving information in the IO System

  - by djTeller

  Hi Kernel Gurus, I need to write a kernel module that simulate a "multicaster" Using the /proc file system. Basically it need to support the following scenarios: 1) allow one write access to the /proc file and many read accesses to the /proc file. 2) The module should have a buffer of the contents last successful write. Each write should be matched by a read from all reader. Consider scenario 2, a writer wrote something and there are two readers (A and B), A read the content of the buffer, and then A tried to read again, in this case it should go into a wait_queue and wait for the next message, it should not get the same buffer again. I need to keep a map of all the pid's that already read the current buffer, and in case they try to read again and the buffer was not changed, they should be blocked until there is a new buffer. I'm trying to figure it there is a way i can save that info without a map. I heard there are some redundant fields inside the I/O system the I can use to flag a process if it already read the current buffer. Can someone give me a tip where should i look for that field ? how can i save info on the current process without keeping a "map" of pid's and buffers ? Thanks!

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• How can I avoid garbage collection delays in Java games? (Best Practices)

  - by Brian

  I'm performance tuning interactive games in Java for the Android platform. Once in a while there is a hiccup in drawing and interaction for garbage collection. Usually it's less than one tenth of a second, but sometimes it can be as large as 200ms on very slow devices. I am using the ddms profiler (part of the Android SDK) to search out where my memory allocations come from and excise them from my inner drawing and logic loops. The worst offender had been short loops done like, for(GameObject gob : interactiveObjects) gob.onDraw(canvas); where every single time the loop was executed there was an iterator allocated. I'm using arrays (ArrayList) for my objects now. If I ever want trees or hashes in an inner loop I know that I need to be careful or even reimplement them instead of using the Java Collections framework since I can't afford the extra garbage collection. That may come up when I'm looking at priority queues. I also have trouble where I want to display scores and progress using Canvas.drawText. This is bad, canvas.drawText("Your score is: " + Score.points, x, y, paint); because Strings, char arrays and StringBuffers will be allocated all over to make it work. If you have a few text display items and run the frame 60 times a second that begins to add up and will increase your garbage collection hiccups. I think the best choice here is to keep char[] arrays and decode your int or double manually into it and concatenate strings onto the beginning and end. I'd like to hear if there's something cleaner. I know there must be others out there dealing with this. How do you handle it and what are the pitfalls and best practices you've discovered to run interactively on Java or Android? These gc issues are enough to make me miss manual memory management, but not very much.

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• My game plays itself?

  - by sc8ing

  I've been making a canvas game in HTML5 and am new to a lot of it. I would like to use solely javascript to create my elements too (it is easier to embed into other sites this way and I feel it is cleaner). I had my game reloading in order to play again, but I want to be able to keep track of the score and multiple other variables without having to put each into the URL (which I have been doing) to make it seem like the game is still going. I'm also going to add "power ups" and other things that need to be "remembered" by the script. Anyways, here's my question. When one player kills another, the game will play itself for a while and make my computer very slow until I reload the page. Why is it doing this? I cleared the interval for the main function (which loops the game and keeps everything running) and this used to make everything stop moving - it no longer does. What's wrong here? This is my game: http://dl.dropbox.com/u/11168436/game/game.html Controls: Move the skier with arrow keys and shoot with M (you shoot in the direction you were last moving in). The snowboarder is moved with ESDF and shoots with Q. Thanks for your time.

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