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• Detect movie being played (Windows)

  - by modosansreves

  Watching a movie is quite a different user activity. User doesn't touch neither mouse nor keyboard. Yet he 'actively' uses the computer. Thus, screensaver shouldn't run, indexing should be performed with care etc. On the other side, playing video requires either using direct write to video memory, or DirectShow, or some other API. This may be the key to the answer. What is the Dead Simple Way to determine that a video is being played?

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• Preprocessor Conditionals

  - by Mike

  I was wondering if it would be possible to have a define which changes values at some point in the code be used in a conditional. Basically something like this: //////////////////////////////////////////// SomeFile.cpp #define SHUTDOWN false while(window->isOpen()) { if(SHUTDOWN) window->close(); // Rest of the main loop } //////////////////////////////////////////// SomeOtherFile.cpp if(Escape.isPressed()) { #undef SHUTDOWN #define SHUTDOWN true } Thus causing the app to close. If it's not, would having a function like RenderWindow* getWindow() { return window; } and then calling if(Escape.isPressed()) getWindow()->close(); The best way to do it? I'd rather not go that route because the classes that are calling the key event are members of the class controlling the main loop and the window, so I'd have to set pointers to the containing class in the smaller classes to call getWindow() and it just seems like a more complicated method. But if I can't do it with preprocessor directives I'll just have to use pointers to the parent class.

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• Local LINQtoSQL Database For Your Windows Phone 7 Application

  - by Tim Murphy

  There aren’t many applications that are of value without having some for of data store.  In Windows Phone development we have a few options.  You can store text directly to isolated storage.  You can also use a number of third party libraries to create or mimic databases in isolated storage.  With Mango we gained the ability to have a native .NET database approach which uses LINQ to SQL.  In this article I will try to bring together the components needed to implement this last type of data store and fill in some of the blanks that I think other articles have left out. Defining A Database The first things you are going to need to do is define classes that represent your tables and a data context class that is used as the overall database definition.  The table class consists of column definitions as you would expect.  They can have relationships and constraints as with any relational DBMS.  Below is an example of a table definition. First you will need to add some assembly references to the code file. using System.ComponentModel;using System.Data.Linq;using System.Data.Linq.Mapping; You can then add the table class and its associated columns.  It needs to implement INotifyPropertyChanged and INotifyPropertyChanging.  Each level of the class needs to be decorated with the attribute appropriate for that part of the definition.  Where the class represents the table the properties represent the columns.  In this example you will see that the column is marked as a primary key and not nullable with a an auto generated value. You will also notice that the in the column property’s set method It uses the NotifyPropertyChanging and NotifyPropertyChanged methods in order to make sure that the proper events are fired. [Table]public class MyTable: INotifyPropertyChanged, INotifyPropertyChanging{ public event PropertyChangedEventHandler PropertyChanged; private void NotifyPropertyChanged(string propertyName) { if(PropertyChanged != null) { PropertyChanged(this, new PropertyChangedEventArgs(propertyName)); } } public event PropertyChangingEventHandler PropertyChanging; private void NotifyPropertyChanging(string propertyName) { if(PropertyChanging != null) { PropertyChanging(this, new PropertyChangingEventArgs(propertyName)); } } private int _TableKey; [Column(IsPrimaryKey = true, IsDbGenerated = true, DbType = "INT NOT NULL Identity", CanBeNull = false, AutoSync = AutoSync.OnInsert)] public int TableKey { get { return _TableKey; } set { NotifyPropertyChanging("TableKey"); _TableKey = value; NotifyPropertyChanged("TableKey"); } } The last part of the database definition that needs to be created is the data context.  This is a simple class that takes an isolated storage location connection string its constructor and then instantiates tables as public properties. public class MyDataContext: DataContext{ public MyDataContext(string connectionString): base(connectionString) { MyRecords = this.GetTable<MyTable>(); } public Table<MyTable> MyRecords;} Creating A New Database Instance Now that we have a database definition it is time to create an instance of the data context within our Windows Phone app.  When your app fires up it should check if the database already exists and create an instance if it does not.  I would suggest that this be part of the constructor of your ViewModel. db = new MyDataContext(connectionString);if(!db.DatabaseExists()){ db.CreateDatabase();} The next thing you have to know is how the connection string for isolated storage should be constructed.  The main sticking point I have found is that the database cannot be created unless the file mode is read/write.  You may have different connection strings but the initial one needs to be similar to the following. string connString = "Data Source = 'isostore:/MyApp.sdf'; File Mode = read write"; Using you database Now that you have done all the up front work it is time to put the database to use.  To make your life a little easier and keep proper separation between your view and your viewmodel you should add a couple of methods to the viewmodel.  These will do the CRUD work of your application.  What you will notice is that the SubmitChanges method is the secret sauce in all of the methods that change data. private myDataContext myDb;private ObservableCollection<MyTable> _viewRecords;public ObservableCollection<MyTable> ViewRecords{ get { return _viewRecords; } set { _viewRecords = value; NotifyPropertyChanged("ViewRecords"); }}public void LoadMedstarDbData(){ var tempItems = from MyTable myRecord in myDb.LocalScans select myRecord; ViewRecords = new ObservableCollection<MyTable>(tempItems);}public void SaveChangesToDb(){ myDb.SubmitChanges();}public void AddMyTableItem(MyTable newScan){ myDb.LocalScans.InsertOnSubmit(newScan); myDb.SubmitChanges();}public void DeleteMyTableItem(MyTable newScan){ myDb.LocalScans.DeleteOnSubmit(newScan); myDb.SubmitChanges();} Updating existing database What happens when you need to change the structure of your database?  Unfortunately you have to add code to your application that checks the version of the database which over time will create some pollution in your codes base.  On the other hand it does give you control of the update.  In this example you will see the DatabaseSchemaUpdater in action.  Assuming we added a “Notes” field to the MyTable structure, the following code will check if the database is the latest version and add the field if it isn’t. if(!myDb.DatabaseExists()){ myDb.CreateDatabase();}else{ DatabaseSchemaUpdater dbUdater = myDb.CreateDatabaseSchemaUpdater(); if(dbUdater.DatabaseSchemaVersion < 2) { dbUdater.AddColumn<MyTable>("Notes"); dbUdater.DatabaseSchemaVersion = 2; dbUdater.Execute(); }} Summary This approach does take a fairly large amount of work, but I think the end product is robust and very native for .NET developers.  It turns out to be worth the investment. del.icio.us Tags: Windows Phone,Windows Phone 7,LINQ to SQL,LINQ,Database,Isolated Storage

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• Twisted Spread: How to authenticate each RPC with digital signature

  - by kronat

  I have remote objects which talk each others with RPCs, using Twisted Spread. I want that objects authenticate messages, before using them, with digital signatures, but I don't know where to start to implement this. In my head, the Root object must have a public/private key pair, and the Client too. When a message is sent, a digital signature of the hash is added, and when it is received, the signature is checked. Is the Protocol part where I need to add these adds and checks? Thank you

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• Filtering forms in MS Access

  - by terence6

  I have a simple form showing products from my database. Each product has a foreign key to manufacturer_id . I would like to filter my form by manufacturer_id instead of default product_id. How I can do that ? I know I must create a macro. Also I've already created a query, that takes manufacturer's name as argument and returns manufacturer_id. So basically it should work in this way, that when I press 'Filter' button on my form, it runs macro that opens my query asking for manufacturer's name. And when the name is returned the whole form is filtered (so somewhere there should be comparison between manufacturer_id in product and that returned from query, but I can't manage to do that). I'm using access 2007. Model:

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• FBConnect Demo Application

  - by gmcalab

  I am running the demo application that is supplied with the facebook-ios-sdk. The application starts in the emulator, with a LogIn button. I click the button which then launches safari to grant access to the application. I log in with my fb creds and allow the application. I am the administrator for the application and I have verified I put in the right app key. After I allow access, it says "Safari cannot open the page because the address in invalid"...this is the url it's trying to go to: http://www.facebook.com/connect/uiserver.php... So am I missing something because the breakpoint for (void)fbDidLogin never gets hit...

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• JavaScript loop stops on "localStorage.removeItem"

  - by user1755603

  Why is the "localStorage.removeItem" stopping the loop? If I remove "localStorage.removeItem" and only leave the "alert", it loops though whole thing, but with "localStorage.removeItem" it stops on the first match. function removeTask() { for (i=0; i < localStorage.length; i++){ checkbox = document.getElementById('utford'+i); if (checkbox.checked == true) { alert(i); localStorage.removeItem(localStorage.key(i)); } } printList(); }

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• Excel 2007 - Worksheet is larger than the window

  - by Chris

  Hi This is an odd problem but frustrating none the less. I have a worksheet saved which is larger than the Excel 2007 "workarea". This means when I open the worksheet I cannot access the corners of the worksheet to reduce the size and the worksheets title bar area (with move,size,minimise etc) is hidden beneath the ribbon , even if I remove the ribbon , I still can't see the title bar. In Excel 2003 I've had a similar effect but I've always been able to hit the "alt" key to access the "Move" option. However in Excel 2007 , hitting "alt" brings up some shortcuts for the ribbon etc but I can't access the worksheet options. Has anyone else know how to access the worksheet drop down when this happens?

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• django forms from two tables referencial integrity

  - by dana

  i have a class named cv,and a class named university, and each user that completes his cv, should choose a University he studyes at. My problem is: one student can study at one or 2 or three universities, or may be a user that is not student. I need to take this data into a form, and i use ModelForm. The data from the Cv class, and from the University class in the same form, and the user can add one or more universities, or no university. (in the same form) How should i do it? Should i use ModelForm? if i have a foreign key in the CV class, and the user is not a student (so he is at zero universities), i may get an referencial integrity error. thanks a lot

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• Trying to modify a constraint in PostgresSQL

  - by MISMajorDeveloperAnyways

  Postgres is getting quite annoying lately. I have checked the documentation provided by Oracle and found a way to do this without dropping the table. Problem is, it errors out at modify as it does not recognize the keyword. Using EMS SQL Manager for PostgreSQL. Alter table public.public_insurer_credit MODIFY CONSTRAINT public_insurer_credit_fk1 deferrable, initially deferred; I was able to work around it by dropping the constraint using : ALTER TABLE "public"."public_insurer_credit" DROP CONSTRAINT "public_insurer_credit_fk1" RESTRICT; ALTER TABLE "public"."public_insurer_credit" ADD CONSTRAINT "public_insurer_credit_fk1" FOREIGN KEY ("branch_id", "order_id", "public_insurer_id") REFERENCES "public"."order_public_insurer"("branch_id", "order_id", "public_insurer_id") ON UPDATE CASCADE ON DELETE NO ACTION DEFERRABLE INITIALLY DEFERRED;

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• Google maps event problem with flex actionscript

  - by DEH

  I am able to render a google map on a flex canvas. I create the map using the code below and then place markers on it in the onMapReady method (not shown) var map:com.google.maps.Map=new com.google.maps.Map(); map.id="map"; map.key="bla bla"; _mapCanvas.addChild(map); map.addEventListener(MapEvent.MAP_READY,onMapReady); It all works fine. However, if I remove the map and then set _mapCanvas to null, then run exactly the same code again, the onMapReady event does not fire. It is weird, but once a map has been created and deleted, the onMapReady event never seems to fire again. Anyone got any ideas? Thanks.

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• How can I select text inside Brackets or Parentheses in Visual Studio?

  - by ksharp

  If I do something over and over again, I'm not happy. So I find ways to handle it. I'm using Visual Studio Express a lot. I try my best to use shortcut key. How can I select text inside Brackets or Parentheses in Visual Studio? In vim. Just type vi} or vi). You also can delete text using di} or di). Can I do this in Visual Studio?

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• Better data-structure design

  - by Tempname

  Currently in my application I have a single table that is giving me a bit of trouble. The issue at hand is I have a value object that is mapped to this table. When the data is returned to me as an array of value objects, I have to then loop through this array and begin my recursion by matching the ParentID to parent ObjectID's. The column ParentID is either null (acts a parent) or it holds the value of an ObjectID. I know there has to be a better way to create this data structure so that I do not have to do recursive loops to match ParentID's with their ObjectID's. Any help with this is greatly appreciated. Here is the table in describe form: +----------------+------------------+------+-----+---------------------+-----------------------------+ | Field | Type | Null | Key | Default | Extra | +----------------+------------------+------+-----+---------------------+-----------------------------+ | ObjectID | int(11) unsigned | NO | PRI | NULL | auto_increment | | ObjectHeight | decimal(6,2) | NO | | NULL | | | ObjectWidth | decimal(6,2) | NO | | NULL | | | ObjectX | decimal(6,2) | NO | | NULL | | | ObjectY | decimal(6,2) | NO | | NULL | | | ObjectLabel | varchar(255) | NO | | NULL | | | TemplateID | int(11) unsigned | NO | MUL | NULL | | | ObjectTypeID | int(11) unsigned | NO | MUL | NULL | | | ParentID | int(11) unsigned | YES | MUL | NULL | | | CreationDate | datetime | YES | | 0000-00-00 00:00:00 | | | LastModifyDate | timestamp | YES | | NULL | on update CURRENT_TIMESTAMP | +----------------+------------------+------+-----+---------------------+-----------------------------+e

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• How do I sum values from two dictionaries in C#?

  - by George Stocker

  I have two dictionaries with the same structure: Dictionary<string, int> foo = new Dictionary<string, int>() { {"Table", 5 }, {"Chair", 3 }, {"Couch", 1 } }; Dictionary<string, int> bar = new Dictionary<string, int>() { {"Table", 4 }, {"Chair", 7 }, {"Couch", 8 } }; I'd like to sum the values of the dictionaries together and return a third dictionaries with the keys, and the total values for each key: Table, 9 Chair, 10 Couch, 9 My current solution is to loop through the dictionary and pull them out that way, but I know that solution isn't the most performant or most readable. However, I'm hitting a brick wall trying to come up with a solution in LINQ.

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• Need to pass the registry path along with launch parameter ...

  - by velusbits

  I have a situation that demands, passing the registry path as a parameter for application launch, say I have IE as default launcher for http types HKEY_CLASSES_ROOT\http\shell\open\command\ Default = iexplore %1 Any shell launch of a URL would invoke iexplore <<"URL String". My requirement is additionally pass the registry path as parameter, so when a launch happens (note no change in the launch) iexplore <<"URL String" should translate into something like iexplore <<"URL String" "HKEY_CLASSES_ROOT\http\shell\open\command\" How should my registry key HKEY_CLASSES_ROOT\http\shell\open\command\ modified so as to get the extra registry path appended for all shell launches ? Any idea is appreciated, Thanks !

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• MinMax Heap implementation without an array

  - by user576531

  Hi. I found lots of MinMax Heap implementations, that were storing data in an array. It is realy easy to implement, that is way I am looking for something different. I want to create a MinMax Heap using only elements of the Heap with pointers to left child and right child (and afcourse a key to compare). So the Heap have only pointer to the root object (min level), and a root object have a pointer to his children (max level) and so on. I know how to insert a new object (finding a proper path by using binary represenation of int depending on Heap size), but I don't know how to implement the rest (push up (down) the element, find parent or grandparent). Thx for help

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• Quick way to do data lookup in PHP

  - by Ghostrider

  I have a data table with 600,000 records that is around 25 megabytes large. It is indexed by a 4 byte key. Is there a way to find a row in such dataset quickly with PHP without resorting to MySQL? The website in question is mostly static with minor PHP code and no database dependencies and therefore fast. I would like to add this data without having to use MySQL if possible. In C++ I would memory map the file and do a binary search in it. Is there a way to do something similar in PHP?

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• DB2 Child Table - Auto Delete With Parent

  - by gamerzfuse

  I have a bit of a task before me. (DB2 Database) I need to create a table that will be a child table (is that what it is called in SQL?) I need it so that it has a foreign key constraint with my other table, so when the parent table is modified (record deleted) the child table also loses that record. Once I have the table, I also need to populate it with the data from the other table (if there is an easy way to UPDATE this). If you could point me in the right direction, this would help alot, as I do not even know what syntax to look for. Thanks in advance

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• rsync useful w/ encrypted files?

  - by barrycarter

  Is rsync efficient for transferring encrypted files? More specifically: I encrypt 'x' with my public key and call the result 'y'. I rsync 'y' to my backup server. 'x' changes slightly I encrypt the modified 'x' and rsync the modified 'y' to my backup server. Is this efficient? I know a small change in 'x' yields a large change in 'y', but is the change localized? Or has 'y' changed so thoroughly that rsync is not much better than scp? I currently backup my "critical" files by tarring/bzipping them nightly, then encrypting the .tar.bz file and rsync'ing it to my backup server. Many of the individual files don't change, but, of course, the tar file changes if even one of the files change. Is this efficient? Should I be encrypting and backing up each file individually? That way, unchanged files will take no time to rsync.

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• How do I specify (1) an order and (2) a meaninful string representation for users in my Django application?

  - by David Faux

  I have a Django application with users. I have a model called "Course" with a foreign key called "teacher" to the default User model that Django provides: class Course(models.Model): ... teacher = models.ForeignKey(User, related_name='courses_taught') When I create a model form to edit information for individual courses, the possible users for the teacher field appear in this long select menu of user names. These users are ordered by ID, which is of meager use to me. How can I order these users by their last names? change the string representation of the User class to be "Firstname Lastname (username)" instead of "username"?

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• ASP.NET profile deletion

  - by Ben Aston

  We use the ASP.NET profile subsystem to associate key-value pairs of information with users. I am implementing functionality for the deletion of users. I have been using the ProfileManager.DeleteProfile(string userName) method, but I have noticed that this leaves a row in the aspnet_Users table in the aspnetdb database we use to store the profile information. Clearly, I could manipulate the database directly, but I am reluctant to do so. What is the best way to ensure all information assocaited with a user is deleted from the aspnetdb? PS: there is a tantalising Membership.DeleteUser(string userName, bool deleteEverything) method, but this returns a database connection error. A web.config issue?

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• rails rollback updates when task fails

  - by ash34

  Hi, I have the following "generate_report" method being called from a rake task, which gets a hash as an input, that contains the reported hours spent by each user on a task and outputs the data as a .csv report. desc "Task reporting" task :report, [:inp_dt] => [:environment] do |t, args| h = select_data(args.inp_dt) /* not shown here */ generate_report(h) end def generate_report(h) out_dir = File.dirname(__FILE__) + '/../../output' myfile = "#{out_dir}" + "/monthly_#{Date.today.strftime("%m%d%Y")}.csv" writer = CSV.open(myfile, 'w') h.each do |h,v| v.each do |key,val| writer << val end end writer.close end where h = {:BILL=>{:PROJA=>["CYR", "00876", "2", 24], :PROJB=>["EPR", "00876", "2", 16]}, :JANE=>{:PROJA=>["TRB", "049576", "2", 16]}} I would like to set/update a 'processed' flag for each reported transaction and only commit the update when the file is written correctly or rollback the updates when the task fails. How can I accomplish this. thanks, ash

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• Wpf application variable not changing

  - by Hasan Zubairi

  In my application I need some variables on almost all the pages so I declared them in Application.xaml like <sys:String x:key="First">First</sys:String> and on one page I change the value in code like Resources["First"] = "This is First"; on the second page when I call the variable like String f = (string)this.TryFindResource("First"); MessageBox.Show(f); the out put is "First" and not "This is First". I also tried like. Application.Current.Properties["First"]

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• Returning messages in Smalltalk

  - by Zachary

  I have a Dictionary of objects I have created in smalltalk, which I am iterating over by enumerating it based on the key/value pairs. For value object in the dictionary, I am calling a method on that object. Based on certain conditions, I would like for this object to be able to add a new member to dictionary, and possibly delete another one. I've been looking at the 'Perform' and 'Messages' facilities in Smalltalk, but I'm not sure if it is even possible to do what I'm trying to do - is it possible to return a message (or multiple messages), which another object can process and perform? For example, could my method return 'removeKey: 19' and 'add object' at the same time? I am using GNU Smalltalk, if it matters.

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• Does introducing foreign keys to MySQL reduce performance

  - by Tam

  I'm building Ruby on Rails 2.3.5 app. By default, Ruby on Rails doesn't provide foreign key contraints so I have to do it manually. I was wondering if introducing foreign keys reduces query performance on the database side enough to make it not worth doing. Performance in this case is my first priority as I can check for data consistency with code. What is your recommendation in general? do you recommend using foreign keys? and how do you suggest I should measure this?

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