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  • Determine the 'Overtype' mode using Javascript

    - by Snorkpete
    We are creating a web app to replace an old-school green-screen application. In the green-screen app, as the user presses the Insert key to switch between overtype and insert modes, the cursor changes to indicate which input mode the user is currently in. In IE (which is the official browser of the company), overtype mode also works, but there's no visual indication as to whether overtype mode is on or not, until the user starts typing and possibly over-writes existing information unexpectedly. I'd like to put some sort of visual indicator on the screen if in overtype mode. How can you determine if the browser is in 'overtype mode' from Javascript? Is there some property or function i can query to determine if the browser is in overtype mode? Even an IE-specific solution would be helpful, since our corporate policy dictates the browser to use as IE7 (pure torture, btw). (I do know that one solution is to do check for key presses of the Insert key. However, it's a solution that I'd prefer to avoid since that method seems a bit flaky & error-prone because I can't guarantee what mode the user would be in BEFORE he/she hits my page. ) The reasoning behind this question: The functionality of this portion of the green-screen app is such that the user can select from a list of 'preformatted bodies of text'. crude eg. The excess for this policy is: $xxxxxx and max limit is:$xxxxxx Date of policy is: xx/xx/xxxx and expires : xx/xx/xxxx Some other irrelevant text After selecting this 'preformatted text', the user would then use overtype to replace the x's with actual values, without disturbing the alignment of the rest of the text. (To be clear, they can still edit any part of the 'preformatted text' if they so wished. It's just that usually, they just wish to replace specific portions of the text. Keeping the alignment is important since these sections of text can end up on printed documents.) Of course, the same effect can be achieved by just selecting the x's to replace first, but it would be helpful (with respect to easing the transition to the web app) to allow old methods of doing things to continue to work, while still allowing 'web methods' to be used by the more tech-savvy users. Essentially, we're trying to make the initial transition from the green-screen app to the web app be as seemless as possible to minimise the resistance from the long-time green-screeners.

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  • GOTO still considered harmful?

    - by Kyle Cronin
    Everyone is aware of Dijkstra's Letters to the editor: go to statement considered harmful (also here .html transcript and here .pdf) and there has been a formidable push since that time to eschew the goto statement whenever possible. While it's possible to use goto to produce unmaintainable, sprawling code, it nevertheless remains in modern programming languages. Even the advanced continuation control structure in Scheme can be described as a sophisticated goto. What circumstances warrant the use of goto? When is it best to avoid? As a followup question: C provides a pair of functions, setjmp and longjmp, that provide the ability to goto not just within the current stack frame but within any of the calling frames. Should these be considered as dangerous as goto? More dangerous? Dijkstra himself regretted that title, of which he was not responsible for. At the end of EWD1308 (also here .pdf) he wrote: Finally a short story for the record. In 1968, the Communications of the ACM published a text of mine under the title "The goto statement considered harmful", which in later years would be most frequently referenced, regrettably, however, often by authors who had seen no more of it than its title, which became a cornerstone of my fame by becoming a template: we would see all sorts of articles under the title "X considered harmful" for almost any X, including one titled "Dijkstra considered harmful". But what had happened? I had submitted a paper under the title "A case against the goto statement", which, in order to speed up its publication, the editor had changed into a "letter to the Editor", and in the process he had given it a new title of his own invention! The editor was Niklaus Wirth. A well thought out classic paper about this topic, to be matched to that of Dijkstra, is Structured Programming with go to Statements (also here .pdf), by Donald E. Knuth. Reading both helps to reestablish context and a non-dogmatic understanding of the subject. In this paper, Dijkstra's opinion on this case is reported and is even more strong: Donald E. Knuth: I believe that by presenting such a view I am not in fact disagreeing sharply with Dijkstra's ideas, since he recently wrote the following: "Please don't fall into the trap of believing that I am terribly dogmatical about [the go to statement]. I have the uncomfortable feeling that others are making a religion out of it, as if the conceptual problems of programming could be solved by a single trick, by a simple form of coding discipline!"

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  • Saving images only available when logged in

    - by James
    Hi, I've been having some trouble getting images to download when logged into a website that requires you to be logged in. The images can only be viewed when you are logged in to the site, but you cannot seem to view them directly in the browser if you copy its location into a tab/new window (it redirects to an error page - so I guess the containing folder has be .htaccess-ed). Anyway, the code I have below allows me to log in and grab the HTML content, which works well - but I cannot grab the images ... this is where I need help! <? // curl.php class Curl { public $cookieJar = ""; public function __construct($cookieJarFile = 'cookies.txt') { $this->cookieJar = $cookieJarFile; } function setup() { $header = array(); $header[0] = "Accept: text/xml,application/xml,application/xhtml+xml,"; $header[0] .= "text/html;q=0.9,text/plain;q=0.8,image/gif;q=0.8,image/x-bitmap;q=0.8,image/jpeg;q=0.8,image/png,*/*;q=0.5"; $header[] = "Cache-Control: max-age=0"; $header[] = "Connection: keep-alive"; $header[] = "Keep-Alive: 300"; $header[] = "Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7"; $header[] = "Accept-Language: en-us,en;q=0.5"; $header[] = "Pragma: "; // browsers keep this blank. curl_setopt($this->curl, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows; U; Windows NT 5.2; en-US; rv:1.8.1.7) Gecko/20070914 Firefox/2.0.0.7'); curl_setopt($this->curl, CURLOPT_HTTPHEADER, $header); curl_setopt($this->curl, CURLOPT_COOKIEJAR, $this->cookieJar); curl_setopt($this->curl, CURLOPT_COOKIEFILE, $this->cookieJar); curl_setopt($this->curl, CURLOPT_AUTOREFERER, true); curl_setopt($this->curl, CURLOPT_FOLLOWLOCATION, true); curl_setopt($this->curl, CURLOPT_RETURNTRANSFER, true); } function get($url) { $this->curl = curl_init($url); $this->setup(); return $this->request(); } function getAll($reg, $str) { preg_match_all($reg, $str, $matches); return $matches[1]; } function postForm($url, $fields, $referer = '') { $this->curl = curl_init($url); $this->setup(); curl_setopt($this->curl, CURLOPT_URL, $url); curl_setopt($this->curl, CURLOPT_POST, 1); curl_setopt($this->curl, CURLOPT_REFERER, $referer); curl_setopt($this->curl, CURLOPT_POSTFIELDS, $fields); return $this->request(); } function getInfo($info) { $info = ($info == 'lasturl') ? curl_getinfo($this->curl, CURLINFO_EFFECTIVE_URL) : curl_getinfo($this->curl, $info); return $info; } function request() { return curl_exec($this->curl); } } ?> And below is the page that uses it. <? // data.php include('curl.php'); $curl = new Curl(); $url = "http://domain.com/login.php"; $newURL = "http://domain.com/go_here.php"; $username = "user"; $password = "pass"; $fields = "user=$username&pass=$password"; // Calling URL $referer = "http://domain.com/refering_page.php"; $html = $curl->postForm($url, $fields, $referer); $html = $curl->get($newURL); echo $html; ?> I've tried putting the direct URL for the image into $newURL but that doesn't get the image - it simply returns an error saying since that folder is not available to view directly. I've tried varying the above in different ways, but I haven't been successful in getting an image, though I have managed to get a screen through basically saying error 405 and/or 406 (but not the image I want). Any help would be great!

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  • Can LINQ-to-SQL omit unspecified columns on insert so a database default value is used?

    - by Todd Ropog
    I have a non-nullable database column which has a default value set. When inserting a row, sometimes a value is specified for the column, sometimes one is not. This works fine in TSQL when the column is omitted. For example, given the following table: CREATE TABLE [dbo].[Table1]( [id] [int] IDENTITY(1,1) NOT NULL, [col1] [nvarchar](50) NOT NULL, [col2] [nvarchar](50) NULL, CONSTRAINT [PK_Table1] PRIMARY KEY CLUSTERED ([id] ASC) ) GO ALTER TABLE [dbo].[Table1] ADD CONSTRAINT [DF_Table1_col1] DEFAULT ('DB default') FOR [col1] The following two statements will work: INSERT INTO Table1 (col1, col2) VALUES ('test value', '') INSERT INTO Table1 (col2) VALUES ('') In the second statement, the default value is used for col1. The problem I have is when using LINQ-to-SQL (L2S) with a table like this. I want to produce the same behavior, but I can't figure out how to make L2S do that. I want to be able to run the following code and have the first row get the value I specify and the second row get the default value from the database: var context = new DataClasses1DataContext(); var row1 = new Table1 { col1 = "test value", col2 = "" }; context.Table1s.InsertOnSubmit(row1); context.SubmitChanges(); var row2 = new Table1 { col2 = "" }; context.Table1s.InsertOnSubmit(row2); context.SubmitChanges(); If the Auto Generated Value property of col1 is False, the first row is created as desired, but the second row fails with a null error on col1. If Auto Generated Value is True, both rows are created with the default value from the database. I've tried various combinations of Auto Generated Value, Auto-Sync and Nullable, but nothing I've tried gives the behavior I want. L2S does not omit the column from the insert statement when no value is specified. Instead it does something like this: INSERT INTO Table1 (col1, col2) VALUES (null, '') ...which of course causes a null error on col1. Is there some way to get L2S to omit a column from the insert statement if no value is given? Or is there some other way to get the behavior I want? I need the default value at the database level because not all row inserts are done via L2S, and in some cases the default value is a little more complex than a hard coded value (e.g. creating the default based on another field) so I'd rather avoid duplicating that logic.

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  • boost::serialization of mutual pointers

    - by KneLL
    First, please take a look at these code: class Key; class Door; class Key { public: int id; Door *pDoor; Key() : id(0), pDoor(NULL) {} private: friend class boost::serialization::access; template <typename A> void serialize(A &ar, const unsigned int ver) { ar & BOOST_SERIALIZATION_NVP(id) & BOOST_SERIALIZATION_NVP(pDoor); } }; class Door { public: int id; Key *pKey; Door() : id(0), pKey(NULL) {} private: friend class boost::serialization::access; template <typename A> void serialize(A &ar, const unsigned int ver) { ar & BOOST_SERIALIZATION_NVP(id) & BOOST_SERIALIZATION_NVP(pKey); } }; BOOST_CLASS_TRACKING(Key, track_selectively); BOOST_CLASS_TRACKING(Door, track_selectively); int main() { Key k1, k_in; Door d1, d_in; k1.id = 1; d1.id = 2; k1.pDoor = &d1; d1.pKey = &k1; // Save data { wofstream f1("test.xml"); boost::archive::xml_woarchive ar1(f1); // !!!!! (1) const Key *pK = &k1; const Door *pD = &d1; ar1 << BOOST_SERIALIZATION_NVP(pK) << BOOST_SERIALIZATION_NVP(pD); } // Load data { wifstream i1("test.xml"); boost::archive::xml_wiarchive ar1(i1); // !!!!! (2) A *pK = &k_in; B *pD = &d_in; // (2.1) //ar1 >> BOOST_SERIALIZATION_NVP(k_in) >> BOOST_SERIALIZATION_NVP(d_in); // (2.2) ar1 >> BOOST_SERIALIZATION_NVP(pK) >> BOOST_SERIALIZATION_NVP(pD); } } The first (1) is a simple question - is it possible to pass objects to archive without pointers? If simply pass objects 'as is' that boost throws exception about duplicated pointers. But I'm confused of creating pointers to save objects. The second (2) is a real trouble. If comment out string after (2.1) then boost will corectly load a first Key object (and init internal Door pointer pDoor), but will not init a second Door (d_in) object. After this I have an inited *k_in* object with valid pointer to Door and empty *d_in* object. If use string (2.2) then boost will create two Key and Door objects somewhere in memory and save addresses in pointers. But I want to have two objects *k_in* and *d_in*. So, if I copy a values of memory objects to local variables then I store only addresses, for example, I can write code after (2.2): d_in.id = pD->id; d_in.pKey = pD->pKey; But in this case I store only a pointer and memory object remains in memory and I cannot delete it, because *d_in.pKey* will be unvalid. And I cannot perform a deep copy with operator=(), because if I write code like this: Key &operator==(const Key &k) { if (this != &k) { id = k.id; // call to Door::operator=() that calls *pKey = *d.pKey and so on *pDoor = *k.pDoor; } return *this; } then I will get a something like recursion of operator=()s of Key and Door. How to implement proper serialization of such pointers?

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  • Use native HBitmap in C# while preserving alpha channel/transparency. Please check this code, it works on my computer...

    - by David
    Let's say I get a HBITMAP object/handle from a native Windows function. I can convert it to a managed bitmap using Bitmap.FromHbitmap(nativeHBitmap), but if the native image has transparency information (alpha channel), it is lost by this conversion. There are a few questions on Stack Overflow regarding this issue. Using information from the first answer of this question (How to draw ARGB bitmap using GDI+?), I wrote a piece of code that I've tried and it works. It basically gets the native HBitmap width, height and the pointer to the location of the pixel data using GetObject and the BITMAP structure, and then calls the managed Bitmap constructor: Bitmap managedBitmap = new Bitmap(bitmapStruct.bmWidth, bitmapStruct.bmHeight, bitmapStruct.bmWidth * 4, PixelFormat.Format32bppArgb, bitmapStruct.bmBits); As I understand (please correct me if I'm wrong), this does not copy the actual pixel data from the native HBitmap to the managed bitmap, it simply points the managed bitmap to the pixel data from the native HBitmap. And I don't draw the bitmap here on another Graphics (DC) or on another bitmap, to avoid unnecessary memory copying, especially for large bitmaps. I can simply assign this bitmap to a PictureBox control or the the Form BackgroundImage property. And it works, the bitmap is displayed correctly, using transparency. When I no longer use the bitmap, I make sure the BackgroundImage property is no longer pointing to the bitmap, and I dispose both the managed bitmap and the native HBitmap. The Question: Can you tell me if this reasoning and code seems correct. I hope I will not get some unexpected behaviors or errors. And I hope I'm freeing all the memory and objects correctly. private void Example() { IntPtr nativeHBitmap = IntPtr.Zero; /* Get the native HBitmap object from a Windows function here */ // Create the BITMAP structure and get info from our nativeHBitmap NativeMethods.BITMAP bitmapStruct = new NativeMethods.BITMAP(); NativeMethods.GetObjectBitmap(nativeHBitmap, Marshal.SizeOf(bitmapStruct), ref bitmapStruct); // Create the managed bitmap using the pointer to the pixel data of the native HBitmap Bitmap managedBitmap = new Bitmap( bitmapStruct.bmWidth, bitmapStruct.bmHeight, bitmapStruct.bmWidth * 4, PixelFormat.Format32bppArgb, bitmapStruct.bmBits); // Show the bitmap this.BackgroundImage = managedBitmap; /* Run the program, use the image */ MessageBox.Show("running..."); // When the image is no longer needed, dispose both the managed Bitmap object and the native HBitmap this.BackgroundImage = null; managedBitmap.Dispose(); NativeMethods.DeleteObject(nativeHBitmap); } internal static class NativeMethods { [StructLayout(LayoutKind.Sequential)] public struct BITMAP { public int bmType; public int bmWidth; public int bmHeight; public int bmWidthBytes; public ushort bmPlanes; public ushort bmBitsPixel; public IntPtr bmBits; } [DllImport("gdi32", CharSet = CharSet.Auto, EntryPoint = "GetObject")] public static extern int GetObjectBitmap(IntPtr hObject, int nCount, ref BITMAP lpObject); [DllImport("gdi32.dll")] internal static extern bool DeleteObject(IntPtr hObject); }

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  • Moving from Linear Probing to Quadratic Probing (hash collisons)

    - by Nazgulled
    Hi, My current implementation of an Hash Table is using Linear Probing and now I want to move to Quadratic Probing (and later to chaining and maybe double hashing too). I've read a few articles, tutorials, wikipedia, etc... But I still don't know exactly what I should do. Linear Probing, basically, has a step of 1 and that's easy to do. When searching, inserting or removing an element from the Hash Table, I need to calculate an hash and for that I do this: index = hash_function(key) % table_size; Then, while searching, inserting or removing I loop through the table until I find a free bucket, like this: do { if(/* CHECK IF IT'S THE ELEMENT WE WANT */) { // FOUND ELEMENT return; } else { index = (index + 1) % table_size; } while(/* LOOP UNTIL IT'S NECESSARY */); As for Quadratic Probing, I think what I need to do is change how the "index" step size is calculated but that's what I don't understand how I should do it. I've seen various pieces of code, and all of them are somewhat different. Also, I've seen some implementations of Quadratic Probing where the hash function is changed to accommodated that (but not all of them). Is that change really needed or can I avoid modifying the hash function and still use Quadratic Probing? EDIT: After reading everything pointed out by Eli Bendersky below I think I got the general idea. Here's part of the code at http://eternallyconfuzzled.com/tuts/datastructures/jsw_tut_hashtable.aspx: 15 for ( step = 1; table->table[h] != EMPTY; step++ ) { 16 if ( compare ( key, table->table[h] ) == 0 ) 17 return 1; 18 19 /* Move forward by quadratically, wrap if necessary */ 20 h = ( h + ( step * step - step ) / 2 ) % table->size; 21 } There's 2 things I don't get... They say that quadratic probing is usually done using c(i)=i^2. However, in the code above, it's doing something more like c(i)=(i^2-i)/2 I was ready to implement this on my code but I would simply do: index = (index + (index^index)) % table_size; ...and not: index = (index + (index^index - index)/2) % table_size; If anything, I would do: index = (index + (index^index)/2) % table_size; ...cause I've seen other code examples diving by two. Although I don't understand why... 1) Why is it subtracting the step? 2) Why is it diving it by 2?

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  • How to represent different entities that have identical behavior?

    - by Dominik
    I have several different entities in my domain model (animal species, let's say), which have a few properties each. The entities are readonly (they do not change state during the application lifetime) and they have identical behavior (the differ only by the values of properties). How to implement such entities in code? Unsuccessful attempts: Enums I tried an enum like this: enum Animals { Frog, Duck, Otter, Fish } And other pieces of code would switch on the enum. However, this leads to ugly switching code, scattering the logic around and problems with comboboxes. There's no pretty way to list all possible Animals. Serialization works great though. Subclasses I also thought about where each animal type is a subclass of a common base abstract class. The implementation of Swim() is the same for all Animals, though, so it makes little sense and serializability is a big issue now. Since we represent an animal type (species, if you will), there should be one instance of the subclass per application, which is hard and weird to maintain when we use serialization. public abstract class AnimalBase { string Name { get; set; } // user-readable double Weight { get; set; } Habitat Habitat { get; set; } public void Swim(); { /* swim implementation; the same for all animals but depends uses the value of Weight */ } } public class Otter: AnimalBase{ public Otter() { Name = "Otter"; Weight = 10; Habitat = "North America"; } } // ... and so on Just plain awful. Static fields This blog post gave me and idea for a solution where each option is a statically defined field inside the type, like this: public class Animal { public static readonly Animal Otter = new Animal { Name="Otter", Weight = 10, Habitat = "North America"} // the rest of the animals... public string Name { get; set; } // user-readable public double Weight { get; set; } public Habitat Habitat { get; set; } public void Swim(); } That would be great: you can use it like enums (AnimalType = Animal.Otter), you can easily add a static list of all defined animals, you have a sensible place where to implement Swim(). Immutability can be achieved by making property setters protected. There is a major problem, though: it breaks serializability. A serialized Animal would have to save all its properties and upon deserialization it would create a new instance of Animal, which is something I'd like to avoid. Is there an easy way to make the third attempt work? Any more suggestions for implementing such a model?

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  • Running an allocation simulation repeatedly breaks after the first run.

    - by Az
    Background I have a bunch of students, their desired projects and the supervisors for the respective projects. I'm running a battery of simulations to see which projects the students end up with, which will allow me to get some useful statistics required for feedback. So, this is essentially a Monte-Carlo simulation where I'm randomising the list of students and then iterating through it, allocating projects until I hit the end of the list. Then the process is repeated again. Note that, within a single session, after each successful allocation of a project the following take place: + the project is set to allocated and cannot be given to another student + the supervisor has a fixed quota of students he can supervise. This is decremented by 1 + Once the quota hits 0, all the projects from that supervisor become blocked and this has the same effect as a project being allocated Code def resetData(): for student in students.itervalues(): student.allocated_project = None for supervisor in supervisors.itervalues(): supervisor.quota = 0 for project in projects.itervalues(): project.allocated = False project.blocked = False The role of resetData() is to "reset" certain bits of the data. For example, when a project is successfully allocated, project.allocated for that project is flipped to True. While that's useful for a single run, for the next run I need to be deallocated. Above I'm iterating through thee three dictionaries - one each for students, projects and supervisors - where the information is stored. The next bit is the "Monte-Carlo" simulation for the allocation algorithm. sesh_id = 1 for trial in range(50): for id in randomiseStudents(1): stud_id = id student = students[id] if not student.preferences: # Ignoring the students who've not entered any preferences for rank in ranks: temp_proj = random.choice(list(student.preferences[rank])) if not (temp_proj.allocated or temp_proj.blocked): alloc_proj = student.allocated_proj_ref = temp_proj.proj_id alloc_proj_rank = student.allocated_rank = rank successActions(temp_proj) temp_alloc = Allocated(sesh_id, stud_id, alloc_proj, alloc_proj_rank) print temp_alloc # Explained break sesh_id += 1 resetData() # Refer to def resetData() above All randomiseStudents(1) does is randomise the order of students. Allocated is a class defined as such: class Allocated(object): def __init__(self, sesh_id, stud_id, alloc_proj, alloc_proj_rank): self.sesh_id = sesh_id self.stud_id = stud_id self.alloc_proj = alloc_proj self.alloc_proj_rank = alloc_proj_rank def __repr__(self): return str(self) def __str__(self): return "%s - Student: %s (Project: %s - Rank: %s)" %(self.sesh_id, self.stud_id, self.alloc_proj, self.alloc_proj_rank) Output and problem Now if I run this I get an output such as this (truncated): 1 - Student: 7720 (Project: 1100241 - Rank: 1) 1 - Student: 7832 (Project: 1100339 - Rank: 1) 1 - Student: 7743 (Project: 1100359 - Rank: 1) 1 - Student: 7820 (Project: 1100261 - Rank: 2) 1 - Student: 7829 (Project: 1100270 - Rank: 1) . . . 1 - Student: 7822 (Project: 1100280 - Rank: 1) 1 - Student: 7792 (Project: 1100141 - Rank: 7) 2 - Student: 7739 (Project: 1100267 - Rank: 1) 3 - Student: 7806 (Project: 1100272 - Rank: 1) . . . 45 - Student: 7806 (Project: 1100272 - Rank: 1) 46 - Student: 7714 (Project: 1100317 - Rank: 1) 47 - Student: 7930 (Project: 1100343 - Rank: 1) 48 - Student: 7757 (Project: 1100358 - Rank: 1) 49 - Student: 7759 (Project: 1100269 - Rank: 1) 50 - Student: 7778 (Project: 1100301 - Rank: 1) Basically, it works perfectly for the first run, but on subsequent runs leading upto the nth run, in this case 50, only a single student-project allocation pair is returned. Thus, the main issue I'm having trouble with is figuring out what is causing this anomalous behaviour especially since the first run works smoothly. Thanks in advance, Az

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  • operator overloading of stream extraction operator in C++ help

    - by Crystal
    I'm having some trouble overloading my stream extraction operator in C++ for a hw assignment. I'm not really sure why I am getting these compile errors since I thought I was doing it right... Here is my code: Complex.h #ifndef COMPLEX_H #define COMPLEX_H class Complex { //friend ostream &operator<<(ostream &output, const Complex &complexObj) const; public: Complex(double = 0.0, double = 0.0); // constructor Complex operator+(const Complex &) const; // addition Complex operator-(const Complex &) const; // subtraction void print() const; // output private: double real; // real part double imaginary; // imaginary part }; #endif Complex.cpp #include <iostream> #include "Complex.h" using namespace std; // Constructor Complex::Complex(double realPart, double imaginaryPart) : real(realPart), imaginary(imaginaryPart) { } // addition operator Complex Complex::operator+(const Complex &operand2) const { return Complex(real + operand2.real, imaginary + operand2.imaginary); } // subtraction operator Complex Complex::operator-(const Complex &operand2) const { return Complex(real - operand2.real, imaginary - operand2.imaginary); } // Overload << operator ostream &Complex::operator<<(ostream &output, const Complex &complexObj) const { cout << '(' << complexObj.real << ", " << complexObj.imaginary << ')'; return output; // returning output allows chaining } // display a Complex object in the form: (a, b) void Complex::print() const { cout << '(' << real << ", " << imaginary << ')'; } main.cpp #include <iostream> #include "Complex.h" using namespace std; int main() { Complex x; Complex y(4.3, 8.2); Complex z(3.3, 1.1); cout << "x: "; x.print(); cout << "\ny: "; y.print(); cout << "\nz: "; z.print(); x = y + z; cout << "\n\nx = y + z: " << endl; x.print(); cout << " = "; y.print(); cout << " + "; z.print(); x = y - z; cout << "\n\nx = y - z: " << endl; x.print(); cout << " = "; y.print(); cout << " - "; z.print(); cout << endl; } Compile erros: complex.cpp(23) : error C2039: '<<' : is not a member of 'Complex' complex.h(5) : see declaration of 'Complex' complex.cpp(24) : error C2270: '<<' : modifiers not allowed on nonmember functions complex.cpp(25) : error C2248: 'Complex::real' : cannot access private member declared in class 'Complex' complex.h(13) : see declaration of 'Complex::real' complex.h(5) : see declaration of 'Complex' complex.cpp(25) : error C2248: 'Complex::imaginary' : cannot access private member declared in class 'Complex' complex.h(14) : see declaration of 'Complex::imaginary' complex.h(5) : see declaration of 'Complex' Thanks!

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  • Javascript childNodes does not find all children of a div when appendchild has been used

    - by yesterdayze
    Alright, I am hoping someone can help me out. I apologize up front that this one may be confusing. I have included an example to try to help ease the confusion as this is better seen then heard. I have created a webpage that contains a group or set of groups. Each group has a subgroup. In a nutshell what is happening is this page will allow me to combine multiple groups containing subgroups into a new group. The page will give the chance to rename the old subgroups before they are combined into new groups in order to avoid confusion. When a group is renamed it will check to make sure there is not already a group with that name. If there is it will copy itself out of it's own group and into that group and then delete the original. If the group does not already exist it will create that group, copy itself in and then delete the original. Subgroups can also be renamed at which point they will move into the group with the same name if it exists, or create a new one if it doesn't. The page has a main div. The main div contains 'new sub group' divs. Inside each of those is another div containing the 'old sub group' divs. I use a loop through the child nodes of the 'new sub group' div when renaming a group in order to find each child node. These are then copied into a new div within the main div. The crux of the problem is this. If I loop through a DIV and copy all of the DIVs in it into a new or existing DIV all is well. When I then try to take that DIV and copy all of it's DIVs into another or new DIV it always skips one of the moved DIVs. For simplicity I have copied the entire working code below. To recreate the issue click the spot where the image should appear next to the name ewrewrwe and rename it to something else. All is well. Now click that new group the same way and name it something else. You will see it skip one each time. I have linked the page here: http://vtbikenight.com/test.html The link is clean, it is my personal website I use for a local motorycle group I am part of. Thanks for the help everyone!!! Please let me know if I can clarify on anything. I know the code is not the best right now, it is just demo code and my intent is to get the concept working then streamline it all.

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  • PHP - static DB class vs DB singleton object

    - by Marco Demaio
    I don't want to create a discussion about singleton better than static or better than global, etc. I read dozens of questions about it on SO, but I couldn't come up with an answer to this SPECIFIC question, so I hope someone could now illuminate me buy answering this question with one (or more) real simple EXAMPLES, and not theoretical discussions. In my app I have the typical DB class needed to perform tasks on DB without having to write everywhere in code mysql_connect/mysql_select_db/mysql... (moreover in future I might decide to use another type of DB engine in place of mySQL so obviously I need a class of abstration). I could write the class either as a static class: class DB { private static $connection = FALSE; //connection to be opened //DB connection values private static $server = NULL; private static $usr = NULL; private static $psw = NULL; private static $name = NULL; public static function init($db_server, $db_usr, $db_psw, $db_name) { //simply stores connections values, withour opening connection } public static function query($query_string) { //performs query over alerady opened connection, if not open, it opens connection 1st } ... } or as a Singletonm class: class DBSingleton { private $inst = NULL; private $connection = FALSE; //connection to be opened //DB connection values private $server = NULL; private $usr = NULL; private $psw = NULL; private $name = NULL; public static function getInstance($db_server, $db_usr, $db_psw, $db_name) { //simply stores connections values, withour opening connection if($inst === NULL) $this->inst = new DBSingleton(); return $this->inst; } private __construct()... public function query($query_string) { //performs query over already opened connection, if connection is not open, it opens connection 1st } ... } Then after in my app if I wanto to query the DB i could do //Performing query using static DB object DB:init(HOST, USR, PSW, DB_NAME); DB::query("SELECT..."); //Performing query using DB singleton $temp = DBSingleton::getInstance(HOST, USR, PSW, DB_NAME); $temp->query("SELECT..."); My simple brain sees Singleton has got the only advantage to avoid declaring as 'static' each method of the class. I'm sure some of you could give me an EXAMPLE of real advantage of singleton in this specific case. Thanks in advance.

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  • Ada: Adding an exception in a separate procedure when reading a file

    - by yCalleecharan
    This is a follow-up of this question: Ada: reading from a file . I would like to add an exception that checks if the file that I'm opening actually exists or not. I have made a separate procedure to avoid code clutter. Here is the main code test_read.adb: with Ada.Text_IO; use Ada.Text_IO; with Ada.Long_Float_Text_IO; with Ada.Float_Text_IO; procedure Test_Read is Input_File : File_Type; Value : Long_Float; procedure Open_Data (File : in Ada.Text_IO.File_Type; Name : in String) is separate; begin Ada.Text_IO.Open (File => Input_File, Mode => Ada.Text_IO.In_File, Name => "fx.txt"); while not End_Of_File (Input_File) loop Ada.Long_Float_Text_IO.Get (File => Input_File, Item => Value); Ada.Long_Float_Text_IO.Put (Item => value, Fore => 3, Aft => 5, Exp => 0); Ada.Text_IO.New_Line; end loop; Ada.Text_IO.Close (File => Input_File); end Test_Read; And here is the separate body test_read-open_data.adb of the procedure Open_Data: separate(test_read) procedure Open_Data (File : in Ada.Text_IO.File_Type; Name : in String) is --this procedure prepares a file for reading begin begin Ada.Text_IO.Open (File => File, Mode => Ada.Text_IO.In_File, Name => Name); exception when Ada.Text_IO.Name_Error => Ada.Text_IO.Put(File => Standard_Error, Item => "File not found."); end; end Open_Data; On compilation I get an error message in the separate body test_read-open_data.adb: actual for "File" must be a variable How to fix this? Thanks a lot...

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  • UIViewController not oreintating. Methods not called

    - by capple
    Greetings, This question does seem to be an ongoing saga in the world of iphone SDK... so heres my contribution... Had two separate projects from the same template... one semi-works, the other not at all... Please let me explain my steps... used this basic GL ES template //iphonedevelopment.blogspot.com/2008/12/opengl-project-template-for-xcode.html had to sort out some of the 'Release' configuration but otherwises has eveything I need to add orientation to a GL ES project. One my first project, did my stuff, then added these methods.... -(BOOL)shouldAutoRotateToInterfaceOrientation ..... -(void)willRotateToInterfaceOrientation .... -(void)didRotateFromInterfaceOrientation .... -(void)willAnimateRotationToInterfaceOrientation .... And understand what they do (or are trying to do in my case), the (BOOL)should... gets called once when the view controller is created, and returns 'YES'. But after that none of the other methods are called! So I started from scratch with a blank template (GL ES one from above)...and added minimum to support auto rotation. But this time none of the methods get called! So I investigated .... //developer.apple.com/iphone/library/qa/qa2010/qa1688.html as it said, I added the GLViewController.view first, then added the GLview as subviews of the application delegate. Nothing! Then found this //www.iphonedevsdk.com/forum/iphone-sdk-development/44993-how-determine-ipad-launch-orientation.html which states to enable orientation notifications [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications]; and then subsequently disable them in the view controller... makes sense...did it, nothing... I think the notifications might be on by default though, since I didn't need to enable them in the first project, yet it still try to verify a orientation (i.e (BOOL)shouldAutoRotate... )... If any one could help me out it would be greatly appreciated as this issue is driving me insane. Thanks in advance. The code can be found here ... http://rapidshare.com/files/392053688/autoRotation.zip N.B These projects avoid nib/xib resources, would like to keep it that way if possible. P.S iPad device not out where I am so I cannot test on a device yet. Would be nice for it to work on the simulator.

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  • Adobe Coldfusion Railo OpenBD Apache Tomcat Multiple Sites

    - by chris hough
    Here's what I am trying to do, unless I am crazy: I am trying to use Tomcat with the multiple workers, so far I got OpenBD working, but having trouble with Railo, and will be tackling Adobe after. each engine deployed as a war separated by different workers I wanted to keep both the sites and engines inside my sites directory I have to remap the symlink for the WEB-INF when I switch engines = have not found a way around this my thought is to have everything separated into modules and I want to be able to execute both cfm and php code in a single site.  Ideally, it would be amazing if there would be a way to not have to remap the symlink as well. thoughts? can this be done? I am trying to mimic how this would be setup on a live server, not using eclipse for example. here is what I am working with so far: my apache workers.properties worker.list=openbd, openbdadmin, railo, railoadmin  worker.openbd.type=ajp13  worker.openbd.host=local.mydev.openbd  worker.openbd.port=8009 worker.openbdadmin.type=ajp13  worker.openbdadmin.host=local.admin.openbd worker.openbdadmin.port=8009   worker.railo.type=ajp13  worker.railo.host=local.mydev.railo  worker.railo.port=8009 worker.railoadmin.type=ajp13  worker.railoadmin.host=local.admin.railo worker.railoadmin.port=8009   my tomcat servers.xml < Host name="local.admin.openbd" appBase="/Users/[myusername]/Websites/coldfusion.engines"  unpackWARs="false" autoDeploy="true" xmlValidation="true" xmlNamespaceAware="false"        < Context path="" docBase="openbd/" reloadable="true" privileged="true" antiResourceLocking="false" anitJARLocking="false" allowLinking="true" < /Host        < Host name="local.admin.railo"   appBase="/Users/[my username]/Websites/coldfusion.engines" unpackWARs="false" autoDeploy="true" xmlValidation="true" xmlNamespaceAware="false"        < Context path="" docBase="railo/"  reloadable="true" privileged="true" antiResourceLocking="false" anitJARLocking="false" allowLinking="true" < /Host < Host name="local.mydev.openbd"   appBase="/Users/[my username]/Websites/coldfusion.engines" unpackWARs="false" autoDeploy="true" xmlValidation="true" xmlNamespaceAware="false" < Context path="" docBase="/Users/[my username]/Websites/example.mydev/wwwroot/"  reloadable="true" privileged="true" antiResourceLocking="false" anitJARLocking="false" allowLinking="true"< /Context < /Host < Host name="local.mydev.railo"   appBase="/Users/[my username]/Websites/coldfusion.engines"  unpackWARs="false" autoDeploy="true" xmlValidation="true" xmlNamespaceAware="false" < Context path="" docBase="/Users/[my username]/Websites/example.mydev/wwwroot/"  reloadable="true" privileged="true" antiResourceLocking="false" anitJARLocking="false" allowLinking="true" < /Host my apache vhosts ServerName local.admin.openbd DocumentRoot /Users/[my username]/Websites/coldfusion.engines/openBD/ #Mount OpenBD and tell it to only server cfml files JkMount /*.cfm openbdadmin ErrorLog "/Users/[my username]/Websites/apache.logs/local_openbdadmin_error.log" ServerName local.admin.railo DocumentRoot /Users/[my username]/Websites/coldfusion.engines/railo/ #Mount Railo and tell it to only server cfml files JkMount /*.cfm railoadmin ErrorLog "/Users/[my username]/Websites/apache.logs/local_railoadmin_error.log" ServerName local.mydev DocumentRoot /Users/[my username]/Websites/example.mydev/wwwroot ErrorLog "/Users/[my username]/Websites/apache.logs/local_example_mydev_error.log" ServerName local.mydev.openbd DocumentRoot /Users/[my username]/Websites/example.mydev/wwwroot #Mount OpenBD and tell it to only server cfml files JkMount /*.cfm openbd ErrorLog "/Users/[my username]/Websites/apache.logs/local_example_mydev_openbd_error.log" ServerName local.mydev.railo DocumentRoot /Users/[my username]/Websites/example.mydev/wwwroot JkMount /*.cfm railo ErrorLog "/Users/[my username]/Websites/apache.logs/local_example_mydev_railo_error.log" my folder structure I am using websites/apache.logs/ websites/coldfusion.engines/ websites/coldfusion.engines/cfusion/ websites/coldfusion.engines/openBD/ websites/coldfusion.engines/railo/ websites/example.mydev/ websites/example.mydev/wwwroot/ websites/example.mydev/wwwroot/index.cfm   websites/example.mydev/wwwroot/index.htm   websites/example.mydev/wwwroot/index.php   error log output [Thu Aug 27 00:54:50.443 2009] [11279:2686719776] [info] init_jk::mod_jk.c (3183): mod_jk/1.2.28 initialized [Thu Aug 27 00:54:51.346 2009] [11280:2686719776] [info] init_jk::mod_jk.c (3183): mod_jk/1.2.28 initialized [Thu Aug 27 00:55:18.963 2009] [11284:2686719776] [info] jk_open_socket::jk_connect.c (594): connect to 127.0.0.1:8009 failed (errno=61) [Thu Aug 27 00:55:18.963 2009] [11284:2686719776] [info] ajp_connect_to_endpoint::jk_ajp_common.c (922): Failed opening socket to (127.0.0.1:8009) (errno=61) [Thu Aug 27 00:55:18.963 2009] [11284:2686719776] [error] ajp_send_request::jk_ajp_common.c (1507): (openbdadmin) connecting to backend failed. Tomcat is probably not started or is listening on the wrong port (errno=61) [Thu Aug 27 00:55:18.963 2009] [11284:2686719776] [info] ajp_service::jk_ajp_common.c (2447): (openbdadmin) sending request to tomcat failed (recoverable), because of error during request sending (attempt=1) [Thu Aug 27 00:55:19.063 2009] [11284:2686719776] [info] jk_open_socket::jk_connect.c (594): connect to 127.0.0.1:8009 failed (errno=61) [Thu Aug 27 00:55:19.063 2009] [11284:2686719776] [info] ajp_connect_to_endpoint::jk_ajp_common.c (922): Failed opening socket to (127.0.0.1:8009) (errno=61) [Thu Aug 27 00:55:19.063 2009] [11284:2686719776] [error] ajp_send_request::jk_ajp_common.c (1507): (openbdadmin) connecting to backend failed. Tomcat is probably not started or is listening on the wrong port (errno=61) [Thu Aug 27 00:55:19.063 2009] [11284:2686719776] [info] ajp_service::jk_ajp_common.c (2447): (openbdadmin) sending request to tomcat failed (recoverable), because of error during request sending (attempt=2) [Thu Aug 27 00:55:19.063 2009] [11284:2686719776] [error] ajp_service::jk_ajp_common.c (2466): (openbdadmin) connecting to tomcat failed. [Thu Aug 27 00:55:19.063 2009] [11284:2686719776] [info] jk_handler::mod_jk.c (2615): Service error=-3 for worker=openbdadmin [Thu Aug 27 00:55:20.377 2009] [11283:2686719776] [info] jk_open_socket::jk_connect.c (594): connect to 127.0.0.1:8009 failed (errno=61) [Thu Aug 27 00:55:20.377 2009] [11283:2686719776] [info] ajp_connect_to_endpoint::jk_ajp_common.c (922): Failed opening socket to (127.0.0.1:8009) (errno=61) [Thu Aug 27 00:55:20.377 2009] [11283:2686719776] [error] ajp_send_request::jk_ajp_common.c (1507): (railoadmin) connecting to backend failed. Tomcat is probably not started or is listening on the wrong port (errno=61) [Thu Aug 27 00:55:20.377 2009] [11283:2686719776] [info] ajp_service::jk_ajp_common.c (2447): (railoadmin) sending request to tomcat failed (recoverable), because of error during request sending (attempt=1) [Thu Aug 27 00:55:20.477 2009] [11283:2686719776] [info] jk_open_socket::jk_connect.c (594): connect to 127.0.0.1:8009 failed (errno=61) [Thu Aug 27 00:55:20.477 2009] [11283:2686719776] [info] ajp_connect_to_endpoint::jk_ajp_common.c (922): Failed opening socket to (127.0.0.1:8009) (errno=61) [Thu Aug 27 00:55:20.477 2009] [11283:2686719776] [error] ajp_send_request::jk_ajp_common.c (1507): (railoadmin) connecting to backend failed. Tomcat is probably not started or is listening on the wrong port (errno=61) [Thu Aug 27 00:55:20.477 2009] [11283:2686719776] [info] ajp_service::jk_ajp_common.c (2447): (railoadmin) sending request to tomcat failed (recoverable), because of error during request sending (attempt=2) [Thu Aug 27 00:55:20.477 2009] [11283:2686719776] [error] ajp_service::jk_ajp_common.c (2466): (railoadmin) connecting to tomcat failed. [Thu Aug 27 00:55:20.477 2009] [11283:2686719776] [info] jk_handler::mod_jk.c (2615): Service error=-3 for worker=railoadmin

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  • C#: Inheritence, Overriding, and Hiding

    - by Rosarch
    I'm having difficulty with an architectural decision for my C# XNA game. The basic entity in the world, such as a tree, zombie, or the player, is represented as a GameObject. Each GameObject is composed of at least a GameObjectController, GameObjectModel, and GameObjectView. These three are enough for simple entities, like inanimate trees or rocks. However, as I try to keep the functionality as factored out as possible, the inheritance begins to feel unwieldy. Syntactically, I'm not even sure how best to accomplish my goals. Here is the GameObjectController: public class GameObjectController { protected GameObjectModel model; protected GameObjectView view; public GameObjectController(GameObjectManager gameObjectManager) { this.gameObjectManager = gameObjectManager; model = new GameObjectModel(this); view = new GameObjectView(this); } public GameObjectManager GameObjectManager { get { return gameObjectManager; } } public virtual GameObjectView View { get { return view; } } public virtual GameObjectModel Model { get { return model; } } public virtual void Update(long tick) { } } I want to specify that each subclass of GameObjectController will have accessible at least a GameObjectView and GameObjectModel. If subclasses are fine using those classes, but perhaps are overriding for a more sophisticated Update() method, I don't want them to have to duplicate the code to produce those dependencies. So, the GameObjectController constructor sets those objects up. However, some objects do want to override the model and view. This is where the trouble comes in. Some objects need to fight, so they are CombatantGameObjects: public class CombatantGameObject : GameObjectController { protected new readonly CombatantGameModel model; public new virtual CombatantGameModel Model { get { return model; } } protected readonly CombatEngine combatEngine; public CombatantGameObject(GameObjectManager gameObjectManager, CombatEngine combatEngine) : base(gameObjectManager) { model = new CombatantGameModel(this); this.combatEngine = combatEngine; } public override void Update(long tick) { if (model.Health <= 0) { gameObjectManager.RemoveFromWorld(this); } base.Update(tick); } } Still pretty simple. Is my use of new to hide instance variables correct? Note that I'm assigning CombatantObjectController.model here, even though GameObjectController.Model was already set. And, combatants don't need any special view functionality, so they leave GameObjectController.View alone. Then I get down to the PlayerController, at which a bug is found. public class PlayerController : CombatantGameObject { private readonly IInputReader inputReader; private new readonly PlayerModel model; public new PlayerModel Model { get { return model; } } private float lastInventoryIndexAt; private float lastThrowAt; public PlayerController(GameObjectManager gameObjectManager, IInputReader inputReader, CombatEngine combatEngine) : base(gameObjectManager, combatEngine) { this.inputReader = inputReader; model = new PlayerModel(this); Model.Health = Constants.PLAYER_HEALTH; } public override void Update(long tick) { if (Model.Health <= 0) { gameObjectManager.RemoveFromWorld(this); for (int i = 0; i < 10; i++) { Debug.WriteLine("YOU DEAD SON!!!"); } return; } UpdateFromInput(tick); // .... } } The first time that this line is executed, I get a null reference exception: model.Body.ApplyImpulse(movementImpulse, model.Position); model.Position looks at model.Body, which is null. This is a function that initializes GameObjects before they are deployed into the world: public void Initialize(GameObjectController controller, IDictionary<string, string> data, WorldState worldState) { controller.View.read(data); controller.View.createSpriteAnimations(data, _assets); controller.Model.read(data); SetUpPhysics(controller, worldState, controller.Model.BoundingCircleRadius, Single.Parse(data["x"]), Single.Parse(data["y"]), bool.Parse(data["isBullet"])); } Every object is passed as a GameObjectController. Does that mean that if the object is really a PlayerController, controller.Model will refer to the base's GameObjectModel and not the PlayerController's overriden PlayerObjectModel?

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  • WPF DataTemplateKey can not find ListBox key

    - by Ryan
    I am fairly new to WPF and am having trouble getting the DataTemplateKey to find my ListBox. <Window.Resources> <ControlTemplate x:Key="FocusTemplate" > <Rectangle Fill="Azure" Width="290" Height="55" /> </ControlTemplate> <Style x:Key="FocusStyle" TargetType="{x:Type Control}"> <Setter Property="Template" Value="{StaticResource FocusTemplate}"/> </Style> <Style TargetType="ListBoxItem"> <EventSetter Event="GotFocus" Handler="ListItem_GotFocus"></EventSetter> </Style> <DataTemplate DataType="{x:Type TextBlock}"> </DataTemplate> <DataTemplate x:Key="CustomListData" DataType="{x:Type ListBox}"> <Border BorderBrush="Black" BorderThickness="1" Margin="-2,0,0,-1"> <Grid> <Grid.RowDefinitions> <RowDefinition Height="55*" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <Grid.RenderTransform> <TransformGroup> <ScaleTransform ScaleX="1" ScaleY="1"/> <SkewTransform AngleX="0" AngleY="0"/> <RotateTransform Angle="0"/> <TranslateTransform X="0" Y="0"/> </TransformGroup> </Grid.RenderTransform> <!--<ScrollViewer x:Name="PART_ContentHost" />--> <TextBox Width="290" TextAlignment="Left" VerticalContentAlignment="Center" BorderThickness="0" BorderBrush="Transparent" Foreground="#FF6FB8FD" FontSize="18" FocusVisualStyle="{StaticResource FocusStyle}" Name="editingBox" TextWrapping="Wrap" Text="{Binding .}" Grid.Column="1" Grid.Row="1" MinHeight="55" Cursor="Hand" IsReadOnly="True" > <TextBox.Background> <LinearGradientBrush EndPoint="0,1" StartPoint="0,0"> <LinearGradientBrush.RelativeTransform> <TransformGroup> <ScaleTransform CenterX="0.5" CenterY="0.5"/> <SkewTransform CenterX="0.5" CenterY="0.5"/> <RotateTransform Angle="0" CenterX="0.5" CenterY="0.5"/> <TranslateTransform/> </TransformGroup> </LinearGradientBrush.RelativeTransform> <GradientStop Color="#FF2D4984"/> <GradientStop Color="#FF182D56" Offset="0.042"/> </LinearGradientBrush> </TextBox.Background> </TextBox> </Grid> </Border> </DataTemplate> <Style TargetType="{x:Type ListBox}"> <Setter Property="ItemTemplate" Value="{StaticResource CustomListData }" /> <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Disabled" /> </Style> </Window.Resources> <Window.DataContext> <ObjectDataProvider ObjectType="{x:Type local:ImageLoader}" MethodName="LoadImages" /> </Window.DataContext> <ListBox ItemsSource="{Binding}" Width="320" Background="#FF021422" BorderBrush="#FF1C4B79"> <ListBox.Resources> <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}">Transparent</SolidColorBrush> </ListBox.Resources> </ListBox> The following code will find a TextBlock var key = new System.Windows.DataTemplateKey(typeof(TextBlock)); var r = (DataTemplate)this.FindResource(key); However, when I change the type to ListBox, the key can not be found. What have I missed? Thanks Ryan

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  • How to bind Lists of a custom view model to a dropDownList an get the selected value after POST in A

    - by user187220
    I have following problem. In my view model I defined some list properties as follows: public class BasketAndOrderSearchCriteriaViewModel { List<KeyValuePair> currencies; public ICollection<KeyValuePair> Currencies { get { if (this.currencies == null) this.currencies = new List<KeyValuePair>(); return this.currencies; } } List<KeyValuePair> deliverMethods; public ICollection<KeyValuePair> DeliveryMethods { get { if (this.deliverMethods == null) this.deliverMethods = new List<KeyValuePair>(); return this.deliverMethods; } } } This view model is embedded in another view model: public class BasketAndOrderSearchViewModel { public BasketAndOrderSearchCriteriaViewModel Criteria { [System.Diagnostics.DebuggerStepThrough] get { return this.criteria; } } } I use 2 action methods; one is for the GET and the other for POST: [HttpGet] public ActionResult Search(BasketAndOrderSearchViewModel model){...} [HttpPost] public ActionResult SubmitSearch(BasketAndOrderSearchViewModel model){...} In the view I implement the whole view model by using the EditorFor-Html Helper which does not want to automatically display DropDownLists for List properties! 1. Question: How can you let EditorFor display DropDownLists? Since I could not figure out how to display DropDownLists by using EditorFor, I used the DropDownList Html helper and filled it through the view model as follows: public IEnumerable<SelectListItem> DeliveryMethodAsSelectListItem() { List<SelectListItem> list = new List<SelectListItem>(); list.Add(new SelectListItem() { Selected = true, Text = "<Choose Delivery method>", Value = "0" }); foreach (var item in this.DeliveryMethods) { list.Add(new SelectListItem() { Selected = false, Text = item.Value, Value = item.Key }); } return list; } My 2. question: As you can see I pass my view model to the action metho with POST attribute! Is there a way to get the selected value of a DropDownList get binded to the passed view model? At the moment all the DropDownList are empty and the selected value can only be fetched by the Request.Form which I definitely want to avoid! I would greatly appreciate some ideas or tips on this!

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  • 1>main.obj : error LNK2001: unresolved external symbol _D3D10CreateDeviceAndSwapChain@32

    - by numerical25
    having trouble getting my directx going I get the following error 1>Linking... 1>main.obj : error LNK2001: unresolved external symbol _D3D10CreateDeviceAndSwapChain@32 1>C:\Users\numerical25\Desktop\Intro ToDirectX\msdnTutorials\tutorial0\tutorial\Debug\tutorial.exe : fatal error LNK1120: 1 unresolved externals below is my code // include the basic windows header file #include <windows.h> #include <windowsx.h> #include <d3d10.h> ID3D10Device* g_pd3dDevice; IDXGISwapChain* g_pSwapChain; // the WindowProc function prototype LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam); bool InitDirect3D(HWND); // the entry point for any Windows program int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) { // the handle for the window, filled by a function HWND hWnd; // this struct holds information for the window class WNDCLASSEX wc; // clear out the window class for use ZeroMemory(&wc, sizeof(WNDCLASSEX)); // fill in the struct with the needed information wc.cbSize = sizeof(WNDCLASSEX); wc.style = CS_HREDRAW | CS_VREDRAW; wc.lpfnWndProc = WindowProc; wc.hInstance = hInstance; wc.hCursor = LoadCursor(NULL, IDC_ARROW); wc.hbrBackground = (HBRUSH)COLOR_WINDOW; wc.lpszClassName = L"WindowClass1"; // register the window class RegisterClassEx(&wc); // create the window and use the result as the handle hWnd = CreateWindowEx(NULL, L"WindowClass1", // name of the window class L"Our First Windowed Program", // title of the window WS_OVERLAPPEDWINDOW, // window style 300, // x-position of the window 300, // y-position of the window 640, // width of the window 480, // height of the window NULL, // we have no parent window, NULL NULL, // we aren't using menus, NULL hInstance, // application handle NULL); // used with multiple windows, NULL // display the window on the screen ShowWindow(hWnd, nCmdShow); // enter the main loop: // this struct holds Windows event messages MSG msg; bool finished = InitDirect3D(hWnd); // Enter the infinite message loop while(TRUE) { // Check to see if any messages are waiting in the queue while(PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) { // Translate the message and dispatch it to WindowProc() TranslateMessage(&msg); DispatchMessage(&msg); } // If the message is WM_QUIT, exit the while loop if(msg.message == WM_QUIT) break; // Run game code here // ... // ... }; } // this is the main message handler for the program LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) { // sort through and find what code to run for the message given switch(message) { // this message is read when the window is closed case WM_DESTROY: { // close the application entirely PostQuitMessage(0); return 0; } break; } // Handle any messages the switch statement didn't return DefWindowProc (hWnd, message, wParam, lParam); } bool InitDirect3D(HWND g_hWnd) { DXGI_SWAP_CHAIN_DESC sd; ZeroMemory( &sd, sizeof(sd) ); sd.BufferCount = 1; sd.BufferDesc.Width = 640; sd.BufferDesc.Height = 480; sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM; sd.BufferDesc.RefreshRate.Numerator = 60; sd.BufferDesc.RefreshRate.Denominator = 1; sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT; sd.OutputWindow = g_hWnd; sd.SampleDesc.Count = 1; sd.SampleDesc.Quality = 0; sd.Windowed = TRUE; if( FAILED( D3D10CreateDeviceAndSwapChain( NULL, D3D10_DRIVER_TYPE_REFERENCE, NULL, 0, D3D10_SDK_VERSION, &sd, &g_pSwapChain, &g_pd3dDevice ) ) ) { return FALSE; } return TRUE; }

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  • manuplating matrix operation(transpose, negation, addition, and mutipication) using functions in c

    - by user292489
    i was trying to manuplate matrices in my input file using functions. my input file is, A 3 3 1 2 3 4 5 6 7 8 9 B 3 3 1 0 0 0 1 0 0 0 1 C 2 3 3 5 8 -1 -2 -3 D 3 5 0 0 0 1 0 1 0 1 0 1 0 1 0 0 1 E 1 1 10 F 3 10 1 0 2 0 3 0 4 0 5 0 0 2 3 -1 -3 -4 -3 8 3 7 0 0 0 4 6 5 8 2 -1 10 i am having trouble in impementing the funcitons that i declared. i assumed my program will perform those operations: transpose, negate, add, and mutiply matices according to the users choise: /* once this program is compliled and excuted, it will perform the basic matrix operations: negation, transpose,a\ ddition, and multiplication. */ #include <stdio.h> #include <stdlib.h> #define MAX 10 int readmatrix(FILE *input, char martixname[6],int , mat[10][10], int i, int j); void printmatrix(char matrixname[6], int mat[10][10], int i, int j); void Negate(char matrixname[6], int mat[10][10], int i, int j); void add(char matrixname[6], int mat[10][10],int i, int k); void multiply(char matrixname[], int mat[][10], char A[], int i, int k); void transpose (char matrixname[], int mat[][10], char A[], int); void printT(int mat[][10], int); int selctoption(); char selectmatrix(); int main(int argc, char *argv[]) { char matrixtype[6]; int mat[][10]; FILE *filein; int size; int optionop; int matrixop; int option; if (argc != 2) { printf("Usage: excutable input.\n"); exit (0); } filein = fopen(argv[1], "r"); if (!filein) { printf("ERROR: input file not found.\n"); exit (0); } size = readmatrix (filein, matrixtype); printmatrix(matrix[][10], size); option = selectoption(); matrixtype = selectmatrix(); //printf("You have: %5.2f ", deposit); optionop = readmatrix(option, matrix[][10], size); if (choiceop == 6) { printf("Thanks for using the matrix operation program.\n"); exit(0); } printf("Please select from the following matrix operations:\n") printf("\t1. Print matrix\n"); printf("\t2. Negate matrix\n"); printf("\t3. Transpose matrix\n"); printf("\t4. Add matrices\n"); printf("\t5. Multiply matrices\n"); printf("\t6. Quit\n"); fclose(filein); return 0; } do { printf("Please select option(1-%d):", optionop); scanf("%d", &matrixop); }while(matrixop <= 0 || matrixop > optionop); void readmatrix (FILE *in, int mat[][10], char A[], int i, int j) { int i=0,j = 0; while (fscanf(in, "%d", &mat[i][j]) != EOF) return 0; } // i would apprtaite anyones feedback. //thank you!

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  • How to write this Linq SQL as a Dynamic Query (using strings)?

    - by Dr. Zim
    Skip to the "specific question" as needed. Some background: The scenario: I have a set of products with a "drill down" filter (Query Object) populated with DDLs. Each progressive DDL selection will further limit the product list as well as what options are left for the DDLs. For example, selecting a hammer out of tools limits the Product Sizes to only show hammer sizes. Current setup: I created a query object, sent it to a repository, and fed each option to a SQL "table valued function" where null values represent "get all products". I consider this a good effort, but far from DDD acceptable. I want to avoid any "programming" in SQL, hopefully doing everything with a repository. Comments on this topic would be appreciated. Specific question: How would I rewrite this query as a Dynamic Query? A link to something like 101 Linq Examples would be fantastic, but with a Dynamic Query scope. I really want to pass to this method the field in quotes "" for which I want a list of options and how many products have that option. from p in db.Products group p by p.ProductSize into g select new Category { PropertyType = g.Key, Count = g.Count() } Each DDL option will have "The selection (21)" where the (21) is the quantity of products that have that attribute. Upon selecting an option, all other remaining DDLs will update with the remaining options and counts. Edit: Additional notes: .OrderBy("it.City") // "it" refers to the entire record .GroupBy("City", "new(City)") // This produces a unique list of City .Select("it.Count()") //This gives a list of counts... getting closer .Select("key") // Selects a list of unique City .Select("new (key, count() as string)") // +1 to me LOL. key is a row of group .GroupBy("new (City, Manufacturer)", "City") // New = list of fields to group by .GroupBy("City", "new (Manufacturer, Size)") // Second parameter is a projection Product .Where("ProductType == @0", "Maps") .GroupBy("new(City)", "new ( null as string)")// Projection not available later? .Select("new (key.City, it.count() as string)")// GroupBy new makes key an object Product .Where("ProductType == @0", "Maps") .GroupBy("new(City)", "new ( null as string)")// Projection not available later? .Select("new (key.City, it as object)")// the it object is the result of GroupBy var a = Product .Where("ProductType == @0", "Maps") .GroupBy("@0", "it", "City") // This fails to group Product at all .Select("new ( Key, it as Product )"); // "it" is property cast though What I have learned so far is LinqPad is fantastic, but still looking for an answer. Eventually, completely random research like this will prevail I guess. LOL. Edit:

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  • Window Media Player issues two requests for the audio on web page

    - by Ron Harlev
    I'm using Windows Media Player in a web page. I have version 11 installed so that is the version I'm testing with right now. The player is embedded on the page with this HTML: <OBJECT id='MS_mediaPlayer' width="400" height="45" classid='CLSID:6BF52A52-394A-11D3-B153-00C04F79FAA6' codebase='http://activex.microsoft.com/activex/controls/mplayer/en/nsmp2inf.cab#Version=5,1,52,701' standby='Loading Microsoft Windows Media Player components...' type='application/x-oleobject'> <param name='autoStart' value="false"> <param name='uiMode' value="invisible"> <param name='loop' value="false"> </OBJECT> I'm calling in JavaScript: MS_mediaPlayer.URL = "SomeAudioFile.mp3" MS_mediaPlayer.controls.play(); When I look at Fiddler I can see that the player actually downloads "SomeAudioFile.mp3" twice. Is there some setting I have wrong? I was trying to set the "autoPlay" to true and avoid calling "play()". Got the same result - two downloads. UPDATE: The first request's user-agent is "Windows-Media-Player/11.0.5721.5268". The second has "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; GTB6; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)". Looks like the browser is running the same request the second time. No Idea why Any ideas? UPDATE (4/1/10): Still no solution. I debugged the JS thoroughly and there is only one call to MediaPlayer.URL='.....' to set the audio file. Nothing else triggers the media player to load the file and there is no other place referencing the audio file on the page. One other interesting fact is that this doesn't happen (the double loading of the audio) when I run the browser locally on my development web server. But other remote requests to the same web server generate the double audio loading. I believe I eliminated any correlation with specific IE version or media player version. This happens with IE6-8 and WM9-12

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  • Why is it still so hard to write software?

    - by nornagon
    Writing software, I find, is composed of two parts: the Idea, and the Implementation. The Idea is about thinking: "I have this problem; how do I solve it?" and further, "how do I solve it elegantly?" The answers to these questions are obtainable by thinking about algorithms and architecture. The ideas come partially through analysis and partially through insight and intuition. The Idea is usually the easy part. You talk to your friends and co-workers and you nut it out in a meeting or over coffee. It takes an hour or two, plus revisions as you implement and find new problems. The Implementation phase of software development is so difficult that we joke about it. "Oh," we say, "the rest is a Simple Matter of Code." Because it should be simple, but it never is. We used to write our code on punch cards, and that was hard: mistakes were very difficult to spot, so we had to spend extra effort making sure every line was perfect. Then we had serial terminals: we could see all our code at once, search through it, organise it hierarchically and create things abstracted from raw machine code. First we had assemblers, one level up from machine code. Mnemonics freed us from remembering the machine code. Then we had compilers, which freed us from remembering the instructions. We had virtual machines, which let us step away from machine-specific details. And now we have advanced tools like Eclipse and Xcode that perform analysis on our code to help us write code faster and avoid common pitfalls. But writing code is still hard. Writing code is about understanding large, complex systems, and tools we have today simply don't go very far to help us with that. When I click "find all references" in Eclipse, I get a list of them at the bottom of the window. I click on one, and I'm torn away from what I was looking at, forced to context switch. Java architecture is usually several levels deep, so I have to switch and switch and switch until I find what I'm really looking for -- by which time I've forgotten where I came from. And I do that all day until I've understood a system. It's taxing mentally, and Eclipse doesn't do much that couldn't be done in 1985 with grep, except eat hundreds of megs of RAM. Writing code has barely changed since we were staring at amber on black. We have the theoretical groundwork for much more advanced tools, tools that actually work to help us comprehend and extend the complex systems we work with every day. So why is writing code still so hard?

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  • General Questions on setting up Subversion (w/Netbeans) and web development workflow.

    - by Roeland
    Hey guys, I am web developer who currently works mostly on his own but, some projects require outside coding help (my brother.) Anyway, after running in to the problem of "working on the same files" and "saving over each others edits" I decided to research ways to avoid this. Through the help of stackoverflow I decided on subversion. My setup is the following: A windows 2008 server with a clean install. My desktop which is on the local network of the server. Then my brothers desktop which is at his house, not on lan. We both prefer to use netbeans for development. My Questions: How do we set this thing up correctly and most optimally. Here is my current setup and work flow. dev site: in the past I just created sub domains with my web host for test sites (company1.bythepixel.com, company2.bythepixel.com), and editted those sites with netbeans set up having remote sources (ftp). how do i set up my netbeans now? should I set it up with remote sources? I guess I may need to set up a web server on my local server. I'm just not sure of the work flow. When i hit save in netbeans.. will it update the repository.. then do i need to update the site from the repository somehow? live site: when going live, i would just copy all the files from the dev site into the live site. from what i gather i should be able to update the site from the dev repository? Currently I am toying with virtualsvn server (http://www.visualsvn.com/server/) on my local server. It looks like it is set up to use the http protocol. Is there advantages to this or should I consider something that does the file//. Do you recommend any other subversion software that would run on my 2008 box? how will my brother connect? should i set up a permanent vpn from his house to mine? suggestions? (not that important) how do I deal with databases, there anyway to do subversion on database? I know I have a lot of questions and I am trying to read / make sense of the free online subversion book, but its all so overwhelming! Wish there was a small subversion for dummies guide :)

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  • How to use AVCaptureSession to stream live preview video, then take a photo, then return to streaming

    - by Matthew
    I have an application that creates its own live preview prior to taking a still photo. The app needs to run some processing on the image data and thus is not able to rely on AVCaptureVideoPreviewLayer. Getting the initial stream to work is going quite well, using Apple's example code. The problem comes when I try to switch to the higher quality image to take the snapshot. In response to a button press I attempt to reconfigure the session for taking a full resolution photo. I've tried many variations but here is my latest example (which still does not work): - (void)sessionSetupForPhoto { [session beginConfiguration]; session.sessionPreset = AVCaptureSessionPresetPhoto; AVCaptureStillImageOutput *output = [[[AVCaptureStillImageOutput alloc] init] autorelease]; for (AVCaptureOutput *output in [session outputs]) { [session removeOutput:output]; } if ([session canAddOutput:output]){ [session addOutput:output]; } else { NSLog(@"Not able to add an AVCaptureStillImageOutput"); } [session commitConfiguration]; } I am consistently getting an error message just after the commitConfiguration line that looks like this: (that is to say, I am getting an AVCaptureSessionRuntimeErrorNotification sent to my registered observer) Received an error: NSConcreteNotification 0x19d870 {name = AVCaptureSessionRuntimeErrorNotification; object = ; userInfo = { AVCaptureSessionErrorKey = "Error Domain=AVFoundationErrorDomain Code=-11800 \"The operation couldn\U2019t be completed. (AVFoundationErrorDomain error -11800.)\" UserInfo=0x19d810 {}"; The documentation in XCode ostensibly provides more information for the error number (-11800), "AVErrorUnknown - Reason for the error is unknown."; Previously I had also tried calls to stopRunning and startRunning, but no longer do that after watching WWDC Session 409, where it is discouraged. When I was stopping and starting, I was getting a different error message -11819, which corresponds to "AVErrorMediaServicesWereReset - The operation could not be completed because media services became unavailable.", which is much nicer than simply "unknown", but not necessarily any more helpful. It successfully adds the AVCaptureStillImageOutput (i.e., does NOT emit the log message). I am testing on an iPhone 3g (w/4.1) and iPhone 4. This call is happening in the main thread, which is also where my original AVCaptureSession setup took place. How can I avoid the error? How can I switch to the higher resolution to take the photo? Thank you!

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