Search Results

Search found 36013 results on 1441 pages for 'public fields'.

Page 466/1441 | < Previous Page | 462 463 464 465 466 467 468 469 470 471 472 473  | Next Page >

  • Google App Engine datastore

    - by megala
    Hi i had created table with primarykey{groupname} in google app engine datastore as follows, //---------------coding-----------// @Entity @Table(name="Groups", schema="PUBLIC") public class Creategroup { @Id private String groupname; @Basic private String groupid; . . . } My doubt is I wnat to set groupname and groupid both as primary key is it possible.how ? Guide me thanks in advance

    Read the article

  • Using auto-generated event handler in both class and it's superclass

    - by abatishchev
    I have a abstract class: public abstract class MySuperControl : UserControl { protected void Page_PreRender(object sender, EventArgs e) { // do something in super } } and a class that is code-behind for a designed UserControl: public partial class MyControl : MySuperControl { protected void Page_PreRender(object sender, EventArgs e) { // do something in class } } how do declare both of them to nest automated call?

    Read the article

  • Java "compare cannot be resolved to a type" error

    - by King Triumph
    I'm getting a strange error when attempting to use a comparator with a binary search on an array. The error states that "compareArtist cannot be resolved to a type" and is thrown by Eclipse on this code: Comparator<Song> compare = new Song.compareArtist(); I've done some searching and found references to a possible bug with Eclipse, although I have tried the code on a different computer and the error persists. I've also found similar issues regarding the capitalization of the compare method, in this case compareArtist. I've seen examples where the first word in the method name is capitalized, although it was my understanding that method names are traditionally started with a lower case letter. I have experimented with changing the capitalization but nothing has changed. I have also found references to this error if the class doesn't import the correct package. I have imported java.util in both classes in question, which to my knowledge allows the use of the Comparator. I've experimented with writing the compareArtist method within the class that has the binary search call as well as in the "Song" class, which according to my homework assignment is where it should be. I've changed the constructor accordingly and the issue persists. Lastly, I've attempted to override the Comparator compare method by implementing Comparator in the Song class and creating my own method called "compare". This returns the same error. I've only moved to calling the comparator method something different than "compare" after finding several examples that do the same. Here is the relevant code for the class that calls the binary search that uses the comparator. This code also has a local version of the compareArtist method. While it is not being called currently, the code for this method is the same as the in the class Song, where I am trying to call it from. Thanks for any advice and insight. import java.io.*; import java.util.*; public class SearchByArtistPrefix { private Song[] songs; // keep a direct reference to the song array private Song[] searchResults; // holds the results of the search private ArrayList<Song> searchList = new ArrayList<Song>(); // hold results of search while being populated. Converted to searchResults array. public SearchByArtistPrefix(SongCollection sc) { songs = sc.getAllSongs(); } public int compareArtist (Song firstSong, Song secondSong) { return firstSong.getArtist().compareTo(secondSong.getArtist()); } public Song[] search(String artistPrefix) { String artistInput = artistPrefix; int searchLength = artistInput.length(); Song searchSong = new Song(artistInput, "", ""); Comparator<Song> compare = new Song.compareArtist(); int search = Arrays.binarySearch(songs, searchSong, compare);

    Read the article

  • Impossible to use ref and out in Extension methods?

    - by Hun1Ahpu
    Why is it forbidden to call Extension method with ref modifier? This one is possible: public static void Change(ref TestClass testClass, TestClass testClass2) { testClass = testClass2; } And this one not: public static void ChangeWithExtensionMethod(this ref TestClass testClass, TestClass testClass2) { testClass = testClass2; } But why?

    Read the article

  • Wondering about a way to conserve memory in C# using List<> with structs

    - by Michael Ryan
    I'm not even sure how I should phrase this question. I'm passing some CustomStruct objects as parameters to a class method, and storing them in a List. What I'm wondering is if it's possible and more efficient to add multiple references to a particular instance of a CustomStruct if a equivalent instance it found. This is a dummy/example struct: public struct CustomStruct { readonly int _x; readonly int _y; readonly int _w; readonly int _h; readonly Enum _e; } Using the below method, you can pass one, two, or three CustomStruct objects as parameters. In the final method (that takes three parameters), it may be the case that the 3rd and possibly the 2nd will have the same value as the first. List<CustomStruct> _list; public void AddBackground(CustomStruct normal) { AddBackground(normal, normal, normal); } public void AddBackground(CustomStruct normal, CustomStruct hover) { AddBackground(normal, hover, hover); } public void AddBackground(CustomStruct normal, CustomStruct hover, CustomStruct active) { _list = new List<CustomStruct>(3); _list.Add(normal); _list.Add(hover); _list.Add(active); } As the method stands now, I believe it will create new instances of CustomStruct objects, and then adds a reference of each to the List. It is my understanding that if I instead check for equality between normal and hover and (if equal) insert normal again in place of hover, when the method completes, hover will lose all references and eventually be garbage collected, whereas normal will have two references in the List. The same could be done for active. That would be better, right? The CustomStruct is a ValueType, and therefore one instance would remain on the Stack, and the three List references would just point to it. The overall List size is determined not by the object Type is contains, but by its Capacity. By eliminating the "duplicate" CustomStuct objects, you allow them to be cleaned up. When the CustomStruct objects are passed to these methods, new instances are created each time. When the structs are added to the List, is another copy made? For example, if i pass just one CustomStruct, AddBackground(normal) creates a copy of the original variable, and then passes it three times to Addbackground(normal, hover, active). In this method, three copies are made of the original copy. When the three local variables are added to the List using Add(), are additional copies created inside Add(), and does that defeat the purpose of any equality checks as previously mentioned? Am I missing anything here?

    Read the article

  • Various GPS Android Functionality Questions..

    - by Tyler
    Hello - I have a few questions (so far) with the the LocationManager on Android and GPS in general.. Feel free to answer any number of the questions below, and I appreciate your help in advance! (I noticed this stuff doesn't appear to be documented very well, so hopefully these questions will help others out too!) 1) I am using the following code, but I think there may be extra fluff in here that I do not need. Can you tell me if I can delete any of this? LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE); LocationListener locationListener = new MyLocationListener(); lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener); LocationProvider locationProvider = lm.getProvider("gps"); Location currentLocation = lm.getLastKnownLocation(locationProvider.getName()); 2) Is there a way to hold off on the last step (accessing "getLastKnownLocation" until after I am sure I have a GPS lock? What happens if this is called and GPS is still looking for signal? 3) MOST importantly, I want to ensure I have a GPS lock before I proceed to my next method, so is there a way to check to see if GPS is locked on and getLastKnownLocation is up to date? 4) Is there a way to 'shut down' the GPS listener once it does receive a lock and getLastKnownLocation is updated? I don't see a need to keep this running for my application once I have obtained a lock.. 5) Can you please confirm my assumption that "getLastKnownLocation" is updated frequently as the receiver moves? 6) In my code, I also have a class called "MyLocationListener" (code below) that I honestly just took from another example.. Is this actually needed? I assume this updates my location manager whenever the location changes, but it sure doesn't appear that there is much to the class itself! private class MyLocationListener implements LocationListener { @Override public void onLocationChanged(Location loc) { if (loc != null) { //Toast.makeText(getBaseContext(), "Location changed : Lat: " + loc.getLatitude() + " Lng: " + loc.getLongitude(), Toast.LENGTH_SHORT).show(); } } @Override public void onProviderDisabled(String provider) { // TODO Auto-generated method stub } @Override public void onProviderEnabled(String provider) { // TODO Auto-generated method stub } @Override public void onStatusChanged(String provider, int status, Bundle extras) { // TODO Auto-generated method stub } }

    Read the article

  • How to return Current Object in a Static function in PHP

    - by streetparade
    I neet access to current object in a static method. Code: protected static $name; public static function name($modulename) { self::$name = $modulename; } public function __call($name, $arguments) { $me = new test(self::$name); return $me->$name($arguments); } I want to be able to call method log in Log class. Like this echo Mods::name("Log")->log("test"); How do i do that?

    Read the article

  • trace this java method

    - by Bader
    public static int ABC(int x, int y) { if(y==0) return(0); else return(x + ABC(x,y-1)); } /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub System.out.println(ABC(5,3)); }

    Read the article

  • JAX-WS wsgen and collections of collections: wsgen broken?

    - by ayang
    I've been playing around with "bottom-up" JAX-WS and have come across something odd when running wsgen. If I have a service class that does something like: @WebService public class Foo { public ArrayList<Bar> getBarList(String baz) { ... } } then running wsgen gets me a FooService_schema1.xsd that has something like this: <xs:complexType name="getBarListResponse"> <xs:sequence> <xs:element name="return" type="tns:bar" minOccurs="0" maxOccurs="unbounded"/> </xs:sequence> </xs:complexType> which seems reasonable. However, if I want a collection of collections like: public BarCollection getBarCollection(String baz) { ... } // BarCollection is just a container for an ArrayList<Bar> then the generated schema ends up with stuff like: <xs:complexType name="barCollection"> <xs:sequence/> </xs:complexType> <xs:complexType name="getBookCollectionsResponse"> <xs:sequence> <xs:element name="return" type="tns:barCollection" minOccurs="0" maxOccurs="unbounded"/> </xs:sequence> </xs:complexType> An empty sequence is not what I had in mind at all. My original approach was to go with: public ArrayList<ArrayList<Bar>> getBarLists(String baz) { ... } but that ends up with a big chain of complexTypes that just wind up with an empty sequence at the end as well: <xs:complexType name="getBarListsResponse"> <xs:sequence> <xs:element name="return" type="tns:arrayList" minOccurs="0" maxOccurs="unbounded"/> </xs:sequence> </xs:complexType> <xs:complexType name="arrayList"> <xs:complexContent> <xs:extension base="tns:abstractList"> <xs:sequence/> </xs:extension> </xs:complexContent> </xs:complexType> <xs:complexType name="abstractList" abstract="true"> <xs:complexContent> <xs:extension base="tns:abstractCollection"> <xs:sequence/> </xs:extension> </xs:complexContent> </xs:complexType> <xs:complexType name="abstractCollection" abstract="true"> <xs:sequence/> </xs:complexType> Am I missing something or is this a known hole in wsgen? JAXB? Andy

    Read the article

  • Contact Bubble EditText

    - by toobsco42
    I am trying to create contact bubbles in the MultiAutoCompleteTextView similiar to how it is implemented in the Google+ app. Below is a screen shot: . I have tried to extend the DynamicDrawableSpan class in order to get a spannable drawable in the background of a span of text public class BubbleSpan extends DynamicDrawableSpan { private Context c; public BubbleSpan(Context context) { super(); c = context; } @Override public Drawable getDrawable() { Resources res = c.getResources(); Drawable d = res.getDrawable(R.drawable.oval); d.setBounds(0, 0, 100, 20); return d; } } Where my oval.xml drawable is defined as so: <?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval"> <solid android:color="#00000000"/> <stroke android:width="4dp" android:color="#99000000" android:dashWidth="4dp" android:dashGap="2dp" /> <padding android:left="7dp" android:top="7dp" android:right="7dp" android:bottom="7dp" /> <corners android:radius="4dp" /> </shape> In my Activity class that has the MulitAutoCompleteTextView, I set the bubble span like so: final Editable e = tv.getEditableText(); final SpannableStringBuilder sb = new SpannableStringBuilder(); sb.append("some sample text"); sb.setSpan(new BubbleSpan(getApplicationContext()), 0, 6, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE); e.append(sb); However, instead of the oval shape displaying behind the first 6 characters in the string, the characters are not visible and there is no oval drawable in the background. If i change the BubbleSpan's getDrawable() method to use a .png instead of a shape drawable: public Drawable getDrawable() { Resources res = c.getResources(); Drawable d = res.getDrawable(android.R.drawable.bottom_bar); d.setBounds(0, 0, 100, 20); return d; } Then the .png will show up but the characters in the string that are a part of the span will not show up. How can I make it so that the characters in the span are displayed in the foreground, meanwhile a custom shape drawable gets displayed in the background? I attempted to also use an ImageSpan instead of subclassing DynamicDrawableSpan but was unsuccessful.

    Read the article

  • How safe is my safe rethrow?

    - by gustafc
    (Late edit: This question will hopefully be obsolete when Java 7 comes, because of the "final rethrow" feature which seems like it will be added.) Quite often, I find myself in situations looking like this: do some initialization try { do some work } catch any exception { undo initialization rethrow exception } In C# you can do it like this: InitializeStuff(); try { DoSomeWork(); } catch { UndoInitialize(); throw; } For Java, there's no good substitution, and since the proposal for improved exception handling was cut from Java 7, it looks like it'll take at best several years until we get something like it. Thus, I decided to roll my own: (Edit: Half a year later, final rethrow is back, or so it seems.) public final class Rethrow { private Rethrow() { throw new AssertionError("uninstantiable"); } /** Rethrows t if it is an unchecked exception. */ public static void unchecked(Throwable t) { if (t instanceof Error) throw (Error) t; if (t instanceof RuntimeException) throw (RuntimeException) t; } /** Rethrows t if it is an unchecked exception or an instance of E. */ public static <E extends Exception> void instanceOrUnchecked( Class<E> exceptionClass, Throwable t) throws E, Error, RuntimeException { Rethrow.unchecked(t); if (exceptionClass.isInstance(t)) throw exceptionClass.cast(t); } } Typical usage: public void doStuff() throws SomeException { initializeStuff(); try { doSomeWork(); } catch (Throwable t) { undoInitialize(); Rethrow.instanceOrUnchecked(SomeException.class, t); // We shouldn't get past the above line as only unchecked or // SomeException exceptions are thrown in the try block, but // we don't want to risk swallowing an error, so: throw new SomeException("Unexpected exception", t); } private void doSomeWork() throws SomeException { ... } } It's a bit wordy, catching Throwable is usually frowned upon, I'm not really happy at using reflection just to rethrow an exception, and I always feel a bit uneasy writing "this will not happen" comments, but in practice it works well (or seems to, at least). What I wonder is: Do I have any flaws in my rethrow helper methods? Some corner cases I've missed? (I know that the Throwable may have been caused by something so severe that my undoInitialize will fail, but that's OK.) Has someone already invented this? I looked at Commons Lang's ExceptionUtils but that does other things. Edit: finally is not the droid I'm looking for. I'm only interested to do stuff when an exception is thrown. Yes, I know catching Throwable is a big no-no, but I think it's the lesser evil here compared to having three catch clauses (for Error, RuntimeException and SomeException, respectively) with identical code. Note that I'm not trying to suppress any errors - the idea is that any exceptions thrown in the try block will continue to bubble up through the call stack as soon as I've rewinded a few things.

    Read the article

  • operator+ overload returning object causing memory leaks, C++

    - by lampshade
    The problem i think is with returing an object when i overload the + operator. I tried returning a reference to the object, but doing so does not fix the memory leak. I can comment out the two statements: dObj = dObj + dObj2; and cObj = cObj + cObj2; to free the program of memory leaks. Somehow, the problem is with returning an object after overloading the + operator. #include <iostream> #include <vld.h> using namespace std; class Animal { public : Animal() {}; virtual void eat() = 0 {}; virtual void walk() = 0 {}; }; class Dog : public Animal { public : Dog(const char * name, const char * gender, int age); Dog() : name(NULL), gender(NULL), age(0) {}; virtual ~Dog(); Dog operator+(const Dog &dObj); private : char * name; char * gender; int age; }; class MyClass { public : MyClass() : action(NULL) {}; void setInstance(Animal &newInstance); void doSomething(); private : Animal * action; }; Dog::Dog(const char * name, const char * gender, int age) : // allocating here, for data passed in ctor name(new char[strlen(name)+1]), gender(new char[strlen(gender)+1]), age(age) { if (name) { size_t length = strlen(name) +1; strcpy_s(this->name, length, name); } else name = NULL; if (gender) { size_t length = strlen(gender) +1; strcpy_s(this->gender, length, gender); } else gender = NULL; if (age) { this->age = age; } } Dog::~Dog() { delete name; delete gender; age = 0; } Dog Dog::operator+(const Dog &dObj) { Dog d; d.age = age + dObj.age; return d; } void MyClass::setInstance(Animal &newInstance) { action = &newInstance; } void MyClass::doSomething() { action->walk(); action->eat(); } int main() { MyClass mObj; Dog dObj("Scruffy", "Male", 4); // passing data into ctor Dog dObj2("Scooby", "Male", 6); mObj.setInstance(dObj); // set the instance specific to the object. mObj.doSomething(); // something happens based on which object is passed in dObj = dObj + dObj2; // invoke the operator+ return 0; }

    Read the article

  • To Reference A Generic Method With A Lambda Expression

    - by SDReyes
    It is possible to reference a generic method using a Lambda Expression Object? For example, having: TheObject: public abstract class LambdaExpression : Expression TheMethod (an extension method of LINQ): public static TSource Last<TSource>( this IEnumerable<TSource> source ) I'm trying to create an instance of TheObject, that references to TheMethod. How do you do such thing?

    Read the article

  • C# monkey patching - is it possible?

    - by Adal
    Is it possible to write a C# assembly which when loaded will inject a method into a class from another assembly? If yes, will the injected method be available from languages using DLR, like IronPython? namespace IronPython.Runtime { public class Bytes : IList<byte>, ICodeFormattable, IExpressionSerializable { internal byte[] _bytes; //I WANT TO INJECT THIS METHOD public byte[] getbytes() { return _bytes; } } } I need that method, and I would like to avoid recompiling IronPython if possible.

    Read the article

  • jcuda library usage problem

    - by user513164
    hi m very new to java and Linux i have a code which is taken from examples of jcuda.the code is following import jcuda.CUDA; import jcuda.driver.CUdevprop; import jcuda.driver.types.CUdevice; public class EnumDevices { public static void main(String args[]) { //Init CUDA Driver CUDA cuda = new CUDA(true); int count = cuda.getDeviceCount(); System.out.println("Total number of devices: " + count); for (int i = 0; i < count; i++) { CUdevice dev = cuda.getDevice(i); String name = cuda.getDeviceName(dev); System.out.println("Name: " + name); int version[] = cuda.getDeviceComputeCapability(dev); System.out.println("Version: " + String.format("%d.%d", version[0], version[1])); CUdevprop prop = cuda.getDeviceProperties(dev); System.out.println("Clock rate: " + prop.clockRate + " MHz"); System.out.println("Threads per block: " + prop.maxThreadsPerBlock); } } } I'm using Ubuntu as my operating system i compiled it with following command 1:-javac -cp /home/manish.yadav/Desktop/JCuda-All-0.3.2-bin-linux-x86_64 EnumDevices i got following error error: Class names, 'EnumDevices', are only accepted if annotation processing is explicitly requested 1 error i don't know what is the meaning of this error.what should i do to compile the program than i changed the compiling option which is javac -cp /home/manish.yadav/Desktop/JCuda-All-0.3.2-bin-linux-x86_64 EnumDevices.java than i got following error EnumDevices.java:36: clockRate is not public in jcuda.driver.CUdevprop; cannot be accessed from outside package System.out.println("Clock rate: " + prop.clockRate + " MHz"); ^ EnumDevices.java:37: maxThreadsPerBlock is not public in jcuda.driver.CUdevprop; cannot be accessed from outside package System.out.println("Threads per block: " + prop.maxThreadsPerBlock); ^ 2 errors Now I'm completely confused i don't know what to do? how to compile this program ? how to install the jcuda package or how to use it ? how to use package which have only jar files and .so files and the jar files don't having manifest file ? please help me

    Read the article

  • How to pass an IronPython instance method to a (C#) function parameter of type `Func<Foo>`

    - by Daren Thomas
    I am trying to assign an IronPython instance method to a C# Func<Foo> parameter. In C# I would have a method like: public class CSharpClass { public void DoSomething(Func<Foo> something) { var foo = something() } } And call it from IronPython like this: class IronPythonClass: def foobar(): return Foo() CSharpClass().DoSomething(foobar) But I'm getting the following error: TypeError: expected Func[Foo], got instancemethod

    Read the article

  • Any tips on reducing wxWidgets application code size?

    - by Billy ONeal
    I have written a minimal wxWidgets application: stdafx.h #define wxNO_REGEX_LIB #define wxNO_XML_LIB #define wxNO_NET_LIB #define wxNO_EXPAT_LIB #define wxNO_JPEG_LIB #define wxNO_PNG_LIB #define wxNO_TIFF_LIB #define wxNO_ZLIB_LIB #define wxNO_ADV_LIB #define wxNO_HTML_LIB #define wxNO_GL_LIB #define wxNO_QA_LIB #define wxNO_XRC_LIB #define wxNO_AUI_LIB #define wxNO_PROPGRID_LIB #define wxNO_RIBBON_LIB #define wxNO_RICHTEXT_LIB #define wxNO_MEDIA_LIB #define wxNO_STC_LIB #include <wx/wxprec.h> Minimal.cpp #include "stdafx.h" #include <memory> #include <wx/wx.h> class Minimal : public wxApp { public: virtual bool OnInit(); }; IMPLEMENT_APP(Minimal) DECLARE_APP(Minimal) class MinimalFrame : public wxFrame { DECLARE_EVENT_TABLE() public: MinimalFrame(const wxString& title); void OnQuit(wxCommandEvent& e); void OnAbout(wxCommandEvent& e); }; BEGIN_EVENT_TABLE(MinimalFrame, wxFrame) EVT_MENU(wxID_ABOUT, MinimalFrame::OnAbout) EVT_MENU(wxID_EXIT, MinimalFrame::OnQuit) END_EVENT_TABLE() MinimalFrame::MinimalFrame(const wxString& title) : wxFrame(0, wxID_ANY, title) { std::auto_ptr<wxMenu> fileMenu(new wxMenu); fileMenu->Append(wxID_EXIT, L"E&xit\tAlt-X", L"Terminate the Minimal Example."); std::auto_ptr<wxMenu> helpMenu(new wxMenu); helpMenu->Append(wxID_ABOUT, L"&About\tF1", L"Show the about dialog box."); std::auto_ptr<wxMenuBar> bar(new wxMenuBar); bar->Append(fileMenu.get(), L"&File"); fileMenu.release(); bar->Append(helpMenu.get(), L"&Help"); helpMenu.release(); SetMenuBar(bar.get()); bar.release(); CreateStatusBar(2); SetStatusText(L"Welcome to wxWidgets!"); } void MinimalFrame::OnAbout(wxCommandEvent& e) { wxMessageBox(L"Some text about me!", L"About", wxOK, this); } void MinimalFrame::OnQuit(wxCommandEvent& e) { Close(); } bool Minimal::OnInit() { std::auto_ptr<MinimalFrame> mainFrame( new MinimalFrame(L"Minimal wxWidgets Application")); mainFrame->Show(); mainFrame.release(); return true; } This minimal program weighs in at 2.4MB! (Executable compression drops this to half a MB or so but that's still HUGE!) (I must statically link because this application needs to be single-binary-xcopy-deployed, so both the C runtime and wxWidgets itself are set for static linking) Any tips on cutting this down? (I'm using Microsoft Visual Studio 2010)

    Read the article

  • How do I destruct data associated with an object after the object no longer exists?

    - by Phineas
    I'm creating a class (say, C) that associates data (say, D) with an object (say, O). When O is destructed, O will notify C that it soon will no longer exist :( ... Later, when C feels it is the right time, C will let go of what belonged to O, namely D. If D can be any type of object, what's the best way for C to be able to execute "delete D;"? And what if D is an array of objects? My solution is to have D derive from a base class that C has knowledge of. When the time comes, C calls delete on a pointer to the base class. I've also considered storing void pointers and calling delete, but I found out that's undefined behavior and doesn't call D's destructor. I considered that templates could be a novel solution, but I couldn't work that idea out. Here's what I have so far for C, minus some details: // This class is C in the above description. There may be many instances of C. class Context { public: // D will inherit from this class class Data { public: virtual ~Data() {} }; Context(); ~Context(); // Associates an owner (O) with its data (D) void add(const void* owner, Data* data); // O calls this when he knows its the end (O's destructor). // All instances of C are now aware that O is gone and its time to get rid // of all associated instances of D. static void purge (const void* owner); // This is called periodically in the application. It checks whether // O has called purge, and calls "delete D;" void refresh(); // Side note: sometimes O needs access to D Data *get (const void *owner); private: // Used for mapping owners (O) to data (D) std::map _data; }; // Here's an example of O class Mesh { public: ~Mesh() { Context::purge(this); } void init(Context& c) const { Data* data = new Data; // GL initialization here c.add(this, new Data); } void render(Context& c) const { Data* data = c.get(this); } private: // And here's an example of D struct Data : public Context::Data { ~Data() { glDeleteBuffers(1, &vbo); glDeleteTextures(1, &texture); } GLint vbo; GLint texture; }; }; P.S. If you're familiar with computer graphics and VR, I'm creating a class that separates an object's per-context data (e.g. OpenGL VBO IDs) from its per-application data (e.g. an array of vertices) and frees the per-context data at the appropriate time (when the matching rendering context is current).

    Read the article

  • Unrequired property keeps getting data-val-required attribute

    - by frennky
    This is the model with it's validation: [MetadataType(typeof(TagValidation))] public partial class Tag { } public class TagValidation { [Editable(false)] [HiddenInput(DisplayValue = false)] public int TagId { get; set; } [Required] [StringLength(20)] [DataType(DataType.Text)] public string Name { get; set; } //... } Here is the view: <h2>Create</h2> <script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script> <script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script> @using (Html.BeginForm()) { @Html.ValidationSummary(true) <fieldset> <legend>Tag</legend> <div>@Html.EditorForModel()</div> <p> <input type="submit" value="Create" /> </p> </fieldset> } <div> @Html.ActionLink("Back to List", "Index") </div> And here is what get's renderd: <form action="/Tag/Create" method="post"> <fieldset> <legend>Tag</legend> <div><input data-val="true" data-val-number="The field TagId must be a number." data-val-required="The TagId field is required." id="TagId" name="TagId" type="hidden" value="" /> <div class="editor-label"><label for="Name">Name</label></div> <div class="editor-field"><input class="text-box single-line" data-val="true" data-val-length="The field Name must be a string with a maximum length of 20." data-val-length-max="20" data-val-required="The Name field is required." id="Name" name="Name" type="text" value="" /> <span class="field-validation-valid" data-valmsg-for="Name" data-valmsg-replace="true"></span></div> ... </fieldset> </form> The problem is that TagId validation gets generated althoug thare is no Required attribute set on TagId property. Because of that I can't even pass the client-side validation in order to create new Tag in db. What am I missing?

    Read the article

  • How many significant digits should I use for double literals in Java?

    - by M. Dudley
    How many significant digits should I use when defining a double literal in Java? This is assuming that I am trying to represent a number with more significant figures than a double can hold. In Math.java I see 20 and 21: public static final double E = 2.7182818284590452354; public static final double PI = 3.14159265358979323846; This is more than the 15-17 significant digits provided by IEEE 754. So what's the general rule-of-thumb?

    Read the article

  • remove duplicate code in java

    - by Anantha Kumaran
    class A extends ApiClass { public void duplicateMethod() { } } class B extends AnotherApiClass { public void duplicateMethod() { } } I have two classes which extend different api classes. The two class has some duplicate methods(same method repeated in both class) and how to remove this duplication? Edit The ApiClass is not under my control

    Read the article

  • Implementing a robust async stream reader for a console

    - by Jon
    I recently provided an answer to this question: C# - Realtime console output redirection. As often happens, explaining stuff (here "stuff" was how I tackled a similar problem) leads you to greater understanding and/or, as is the case here, "oops" moments. I realized that my solution, as implemented, has a bug. The bug has little practical importance, but it has an extremely large importance to me as a developer: I can't rest easy knowing that my code has the potential to blow up. Squashing the bug is the purpose of this question. I apologize for the long intro, so let's get dirty. I wanted to build a class that allows me to receive input from a Stream in an event-based manner. The stream, in my scenario, is guaranteed to be a FileStream and there is also an associated StreamReader already present to leverage. The public interface of the class is this: public class MyStreamManager { public event EventHandler<ConsoleOutputReadEventArgs> StandardOutputRead; public void StartSendingEvents(); public void StopSendingEvents(); } Obviously this specific scenario has to do with a console's standard output. StartSendingEvents and StopSendingEvents do what they advertise; for the purposes of this discussion, we can assume that events are always being sent without loss of generality. The class uses these two fields internally: protected readonly StringBuilder inputAccumulator = new StringBuilder(); protected readonly byte[] buffer = new byte[256]; The functionality of the class is implemented in the methods below. To get the ball rolling: public void StartSendingEvents(); { this.stopAutomation = false; this.BeginReadAsync(); } To read data out of the Stream without blocking, and also without requiring a carriage return char, BeginRead is called: protected void BeginReadAsync() { if (!this.stopAutomation) { this.StandardOutput.BaseStream.BeginRead( this.buffer, 0, this.buffer.Length, this.ReadHappened, null); } } The challenging part: BeginRead requires using a buffer. This means that when reading from the stream, it is possible that the bytes available to read ("incoming chunk") are larger than the buffer. Since we are only handing off data from the stream to a consumer, and that consumer may well have inside knowledge about the size and/or format of these chunks, I want to call event subscribers exactly once for each chunk. Otherwise the abstraction breaks down and the subscribers have to buffer the incoming data and reconstruct the chunks themselves using said knowledge. This is much less convenient to the calling code, and detracts from the usefulness of my class. Edit: There are comments below correctly stating that since the data is coming from a stream, there is absolutely nothing that the receiver can infer about the structure of the data unless it is fully prepared to parse it. What I am trying to do here is leverage the "flush the output" "structure" that the owner of the console imparts while writing on it. I am prepared to assume (better: allow my caller to have the option to assume) that the OS will pass me the data written between two flushes of the stream in exactly one piece. To this end, if the buffer is full after EndRead, we don't send its contents to subscribers immediately but instead append them to a StringBuilder. The contents of the StringBuilder are only sent back whenever there is no more to read from the stream (thus preserving the chunks). private void ReadHappened(IAsyncResult asyncResult) { var bytesRead = this.StandardOutput.BaseStream.EndRead(asyncResult); if (bytesRead == 0) { this.OnAutomationStopped(); return; } var input = this.StandardOutput.CurrentEncoding.GetString( this.buffer, 0, bytesRead); this.inputAccumulator.Append(input); if (bytesRead < this.buffer.Length) { this.OnInputRead(); // only send back if we 're sure we got it all } this.BeginReadAsync(); // continue "looping" with BeginRead } After any read which is not enough to fill the buffer, all accumulated data is sent to the subscribers: private void OnInputRead() { var handler = this.StandardOutputRead; if (handler == null) { return; } handler(this, new ConsoleOutputReadEventArgs(this.inputAccumulator.ToString())); this.inputAccumulator.Clear(); } (I know that as long as there are no subscribers the data gets accumulated forever. This is a deliberate decision). The good This scheme works almost perfectly: Async functionality without spawning any threads Very convenient to the calling code (just subscribe to an event) Maintains the "chunkiness" of the data; this allows the calling code to use inside knowledge of the data without doing any extra work Is almost agnostic to the buffer size (it will work correctly with any size buffer irrespective of the data being read) The bad That last almost is a very big one. Consider what happens when there is an incoming chunk with length exactly equal to the size of the buffer. The chunk will be read and buffered, but the event will not be triggered. This will be followed up by a BeginRead that expects to find more data belonging to the current chunk in order to send it back all in one piece, but... there will be no more data in the stream. In fact, as long as data is put into the stream in chunks with length exactly equal to the buffer size, the data will be buffered and the event will never be triggered. This scenario may be highly unlikely to occur in practice, especially since we can pick any number for the buffer size, but the problem is there. Solution? Unfortunately, after checking the available methods on FileStream and StreamReader, I can't find anything which lets me peek into the stream while also allowing async methods to be used on it. One "solution" would be to have a thread wait on a ManualResetEvent after the "buffer filled" condition is detected. If the event is not signaled (by the async callback) in a small amount of time, then more data from the stream will not be forthcoming and the data accumulated so far should be sent to subscribers. However, this introduces the need for another thread, requires thread synchronization, and is plain inelegant. Specifying a timeout for BeginRead would also suffice (call back into my code every now and then so I can check if there's data to be sent back; most of the time there will not be anything to do, so I expect the performance hit to be negligible). But it looks like timeouts are not supported in FileStream. Since I imagine that async calls with timeouts are an option in bare Win32, another approach might be to PInvoke the hell out of the problem. But this is also undesirable as it will introduce complexity and simply be a pain to code. Is there an elegant way to get around the problem? Thanks for being patient enough to read all of this.

    Read the article

  • .htaccess - proxy AND browser caching???

    - by StackOverflowNewbie
    In .htaccess, how do I specify a file type to be cached via browser and proxy? Cache-control for needs to be "private" for browser, "public" for proxy. However, I can't define Cache-Control to be private AND public for same file type. It seems like I have to choose between browser or proxy caching. Suggestions?

    Read the article

< Previous Page | 462 463 464 465 466 467 468 469 470 471 472 473  | Next Page >