Search Results

Search found 23792 results on 952 pages for 'void pointers'.

Page 146/952 | < Previous Page | 142 143 144 145 146 147 148 149 150 151 152 153  | Next Page >

  • Is it possible to overwrite a static method in parent class?

    - by MartinDenny2069
    I have a static method defined in a base class, I want to overwrite this method in its child class, is it possible? I tried this but it did not work as I expected. When I created an instance of class B and invoke its callMe() method, the static foo() method in class A is invoked. public abstract class A { public static void foo() { System.out.println("I am base class"); } public void callMe() { foo(); } } Public class B { public static void foo() { System.out.println("I am child class"); } }

    Read the article

  • Complex sound handling (I.E. pitch change while looping)

    - by Matthew
    Hi everyone I've been meaning to learn Java for a while now (I usually keep myself in languages like C and Lua) but buying an android phone seems like an excellent time to start. now after going through the lovely set of tutorials and a while spent buried in source code I'm beginning to get the feel for it so what's my next step? well to dive in with a fully featured application with graphics, sound, sensor use, touch response and a full menu. hmm now there's a slight conundrum since i can continue to use cryptic references to my project or risk telling you what the application is but at the same time its going to make me look like a raving sci-fi nerd so bare with me for the brief... A semi-working sonic screwdriver (oh yes!) my grand idea was to make an animated screwdriver where sliding the controls up and down modulate the frequency and that frequency dictates the sensor data it returns. now I have a semi-working sound system but its pretty poor for what its designed to represent and I just wouldn't be happy producing a sub-par end product whether its my first or not. the problem : sound must begin looping when the user presses down on the control the sound must stop when the user releases the control when moving the control up or down the sound effect must change pitch accordingly if the user doesn't remove there finger before backing out of the application it must plate the casing of there device with gold (Easter egg ;P) now I'm aware of how monolithic the first 3 look and that's why I would really appreciate any help I can get. sorry for how bad this code looks but my general plan is to create the functional components then refine the code later, no good painting the walls if the roofs not finished. here's my user input, he set slide stuff is used in the graphics for the control @Override public boolean onTouchEvent(MotionEvent event) { //motion event for the screwdriver view if(event.getAction() == MotionEvent.ACTION_DOWN) { //make sure the users at least trying to touch the slider if (event.getY() > SonicSlideYTop && event.getY() < SonicSlideYBottom) { //power setup, im using 1.5 to help out the rate on soundpool since it likes 0.5 to 1.5 SonicPower = 1.5f - ((event.getY() - SonicSlideYTop) / SonicSlideLength); //just goes into a method which sets a private variable in my sound pool class thing mSonicAudio.setPower(1, SonicPower); //this handles the slides graphics setSlideY ( (int) event.getY() ); @Override public boolean onTouchEvent(MotionEvent event) { //motion event for the screwdriver view if(event.getAction() == MotionEvent.ACTION_DOWN) { //make sure the users at least trying to touch the slider if (event.getY() > SonicSlideYTop && event.getY() < SonicSlideYBottom) { //power setup, im using 1.5 to help out the rate on soundpool since it likes 0.5 to 1.5 SonicPower = 1.5f - ((event.getY() - SonicSlideYTop) / SonicSlideLength); //just goes into a method which sets a private variable in my sound pool class thing mSonicAudio.setPower(1, SonicPower); //this handles the slides graphics setSlideY ( (int) event.getY() ); //this is from my latest attempt at loop pitch change, look for this in my soundPool class mSonicAudio.startLoopedSound(); } } if(event.getAction() == MotionEvent.ACTION_MOVE) { if (event.getY() > SonicSlideYTop && event.getY() < SonicSlideYBottom) { SonicPower = 1.5f - ((event.getY() - SonicSlideYTop) / SonicSlideLength); mSonicAudio.setPower(1, SonicPower); setSlideY ( (int) event.getY() ); } } if(event.getAction() == MotionEvent.ACTION_UP) { mSonicAudio.stopLoopedSound(); SonicPower = 1.5f - ((event.getY() - SonicSlideYTop) / SonicSlideLength); mSonicAudio.setPower(1, SonicPower); } return true; } and here's where those methods end up in my sound pool class its horribly messy but that's because I've been trying a ton of variants to get this to work, you will also notice that I begin to hard code the index, again I was trying to get the methods to work before making them work well. package com.mattster.sonicscrewdriver; import java.util.HashMap; import android.content.Context; import android.media.AudioManager; import android.media.SoundPool; public class SoundManager { private float mPowerLvl = 1f; private SoundPool mSoundPool; private HashMap mSoundPoolMap; private AudioManager mAudioManager; private Context mContext; private int streamVolume; private int LoopState; private long mLastTime; public SoundManager() { } public void initSounds(Context theContext) { mContext = theContext; mSoundPool = new SoundPool(2, AudioManager.STREAM_MUSIC, 0); mSoundPoolMap = new HashMap<Integer, Integer>(); mAudioManager = (AudioManager)mContext.getSystemService(Context.AUDIO_SERVICE); streamVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC); } public void addSound(int index,int SoundID) { mSoundPoolMap.put(1, mSoundPool.load(mContext, SoundID, 1)); } public void playUpdate(int index) { if( LoopState == 1) { long now = System.currentTimeMillis(); if (now > mLastTime) { mSoundPool.play(mSoundPoolMap.get(1), streamVolume, streamVolume, 1, 0, mPowerLvl); mLastTime = System.currentTimeMillis() + 250; } } } public void stopLoopedSound() { LoopState = 0; mSoundPool.setVolume(mSoundPoolMap.get(1), 0, 0); mSoundPool.stop(mSoundPoolMap.get(1)); } public void startLoopedSound() { LoopState = 1; } public void setPower(int index, float mPower) { mPowerLvl = mPower; mSoundPool.setRate(mSoundPoolMap.get(1), mPowerLvl); } } ah ha! I almost forgot, that looks pretty ineffective but I omitted my thread which actuality updates it, nothing fancy it just calls : mSonicAudio.playUpdate(1); thanks in advance, Matthew

    Read the article

  • inheritance and hidden overloads

    - by Caspin
    The following code doesn't compile. struct A {}; struct B {}; class Base { public: virtual void method( A param ) { } virtual void method( B param ) = 0; }; class Derived : public Base { public: //using Base::method; void method( B param ) { } }; int main() { Derived derived; derived.method(A()); } The compiler can't find the overload of method() that has an A parameter. The 'fix' is to add a using declaration in the derived class. My question is why. What is the rational for a weird language rule like this? I verified the error in both GCC and Comeau, so I assume this isn't a compiler bug but a feature of the language. Comeau at least gives me this warning: "ComeauTest.c", line 10: warning: overloaded virtual function "Base::method" is only partially overridden in class "Derived" class Derived : public Base ^

    Read the article

  • savedInstanceState cannot be resolved to a variable

    - by Hector
    I'm currently working through "The Android Developers Cookbook" and one of the tutorials involves multiple activities in an app. To give a bit of background right now I have to .java files, a "menu screen" and a "game screen". The menu screen simply has a button that leads to the game screen which is currently empty except for a button that takes you back to the menu screen. Currently the game.java file is giving me a "savedInstanceState error" this is the code I am working on. public void onCreate(Bundle savedInsanceState) { // below is where the error comes up super.onCreate(savedInstanceState); setContentView(R.layout.game); Button startButton = (Button) findViewById(R.id.end_game); startButton.setOnClickListener(new OnClickListener() { public void onClick(View view) { finish(); } }); } I'm not sure why the error is coming up because on the first java file that same "public void...setContentView..." bit of code compiled perfectly fine... Please help!

    Read the article

  • Using injected EntityManager in class hierarchies

    - by Emre Sahin
    The following code works: @Stateless @LocalBean public class MyClass { @PersistenceContext(name = "MyPU") EntityManager em; public void myBusinessMethod(MyEntity e) { em.persist(e); } } But the following hierarchy gives a TransactionRequiredException in Glassfish 3.0 (and standard JPA annotations with EclipseLink.) at the line of persist. @Stateless @LocalBean public class MyClass extends MyBaseClass { public void myBusinessMethod(MyEntity e) { super.update(e); } } public abstract class MyBaseClass { @PersistenceContext(name = "MyPU") EntityManager em; public void update(Object e) { em.persist(e); } } For my EJB's I collected common code in an abstract class for cleaner code. (update also saves who did the operation and when, all my entities implement an interface.) This problem is not fatal, I can simply copy update and sister methods to subclasses but I would like to keep all of them together in a single place. I didn't try but this may be because my base class is abstract, but I would like to learn a proper method for such a (IMHO common) use case.

    Read the article

  • Set Icon in Button LWUIT Java ME

    - by Muhamad Burhanudin
    Please help me, to set icon button : /* * To change this template, choose Tools | Templates * and open the template in the editor. */ package tajwed; import javax.microedition.midlet.*; import com.sun.lwuit.*; import com.sun.lwuit.animations.*; import com.sun.lwuit.events.*; import com.sun.lwuit.layouts.BoxLayout; import com.sun.lwuit.plaf.*; import java.io.IOException; import java.util.Hashtable; /** * @author Muhamad BUrhanudin */ public class tajwedMidlet extends MIDlet implements ActionListener{ Form mHomeForm; Form mAwayForm; Form mMenuTajwid; Command mExitCommand; Button btMenu; Button btNunSukun, btMimSukun, btNunTasjid; Button btLamtarif, btIdgham, btMaad, btRaa; Button btHelp; Button btExit; Command mBackCommand; public void startApp() { Display.init(this); installTheme(); createUI(); mHomeForm.show(); } public void pauseApp() { } public void destroyApp(boolean unconditional) { } public void actionPerformed(ActionEvent ae) { mAwayForm.setTransitionInAnimator( Transition3D.createCube(400, false)); mMenuTajwid.setTransitionInAnimator( Transition3D.createCube(400, false)); mMenuTajwid.setTransitionOutAnimator( Transition3D.createCube(400, true)); mAwayForm.setTransitionOutAnimator( Transition3D.createCube(400, true)); if ((ae.getSource()==btMenu)|| (ae.getSource()==btHelp)) { //mAwayForm.show(); if(ae.getSource()== btMenu) { mMenuTajwid.show(); } } else if (ae.getSource() == mBackCommand) { mHomeForm.show(); } else if ((ae.getCommand() == mExitCommand) || (ae.getSource()== btExit)) notifyDestroyed(); } private void installTheme() { UIManager uim = UIManager.getInstance(); Hashtable ht = new Hashtable(); ht.put("sel#" + Style.BG_COLOR, "ffffff"); ht.put(Style.BG_COLOR, "d5fff9"); ht.put(Style.FG_COLOR, "000000"); uim.setThemeProps(ht); } private void createUI() { // Set up screen for transitions. mAwayForm = new Form("Away"); mAwayForm.addComponent(new Label("Choose Back to return to the home screen.")); mMenuTajwid = new Form("MENU DASAR TAJWID"); // mMenuTajwid mMenuTajwid.setLayout(new BoxLayout(BoxLayout.Y_AXIS)); btNunSukun = new Button("Hukum Nun Sukun & Tanwin"); btNunSukun.addActionListener(this); mMenuTajwid.addComponent(btNunSukun); btMimSukun = new Button("Hukum Mim Sukun"); btMimSukun.addActionListener(this); mMenuTajwid.addComponent(btMimSukun); btNunTasjid = new Button("Hukum Nun Tasydid & Min Tasydid"); btNunTasjid.addActionListener(this); mMenuTajwid.addComponent(btNunTasjid); btLamtarif = new Button("Hukum Laam Ta'rief"); btLamtarif.addActionListener(this); mMenuTajwid.addComponent(btLamtarif); btIdgham = new Button("Idgham"); btIdgham.addActionListener(this); mMenuTajwid.addComponent(btIdgham); btMaad = new Button("Maad"); btMaad.addActionListener(this); mMenuTajwid.addComponent(btMaad); btRaa = new Button("Raa'"); btRaa.addActionListener(this); mMenuTajwid.addComponent(btRaa); mBackCommand = new Command("Back"); mMenuTajwid.addCommand(mBackCommand); mMenuTajwid.addCommandListener(this); // Use setCommandListener() with LWUIT 1.3 or earlier. // Set up main screen. mHomeForm = new Form("Java Mobile Learning"); mHomeForm.setLayout(new BoxLayout(BoxLayout.Y_AXIS)); btMenu = new Button("TAJWID LEARNING"); btMenu.addActionListener(this); mHomeForm.addComponent(btMenu); try { btHelp = new Button("HELP",Image.createImage("/help.ico")); btHelp.addActionListener(this); mHomeForm.addComponent(btHelp); } catch(IOException e) { } btExit = new Button("EXIT"); btExit.addActionListener(this); mHomeForm.addComponent(btExit); mExitCommand = new Command("Keluar"); mHomeForm.addCommand(mExitCommand); mHomeForm.addCommandListener(this); // Use setCommandListener() with LWUIT 1.3 or earlier. } }

    Read the article

  • #include in .h or .c / .cpp ?

    - by Louise
    Hi, When coding in either C or C++, where should I have the #include's? callback.h: #ifndef _CALLBACK_H_ #define _CALLBACK_H_ #include <sndfile.h> #include "main.h" void on_button_apply_clicked(GtkButton* button, struct user_data_s* data); void on_button_cancel_clicked(GtkButton* button, struct user_data_s* data); #endif callback.c: #include <stdlib.h> #include <math.h> #include "config.h" #include "callback.h" #include "play.h" void on_button_apply_clicked(GtkButton* button, struct user_data_s* data) { gint page; page = gtk_notebook_get_current_page(GTK_NOTEBOOK(data->notebook)); ... Should all includes be in either the .h or .c / .cpp, or both like I have done here?

    Read the article

  • Windows 7 Seems to break SWT Control.print(GC)

    - by GreenKiwi
    A bug has been filed and fixed (super quickly) in SWT: https://bugs.eclipse.org/bugs/show_bug.cgi?id=305294 Just to preface this, my goal here is to print the two images into a canvas so that I can animate the canvas sliding across the screen (think iPhone), sliding the controls themselves was too CPU intensive, so this was a good alternative until I tested it on Win7. I'm open to anything that will help me solve my original problem, it doesn't have to be fixing the problem below. Does anyone know how to get "Control.print(GC)" to work with Windows 7 Aero? I have code that works just fine in Windows XP and in Windows 7, when Aero is disabled, but the command: control.print(GC) causes a non-top control to be effectively erased from the screen. GC gc = new GC(image); try { // As soon as this code is called, calling "layout" on the controls // causes them to disappear. control.print(gc); } finally { gc.dispose(); } I have stacked controls and would like to print the images from the current and next controls such that I can "slide" them off the screen. However, upon printing the non-top control, it is never redrawn again. Here is some example code. (Interesting code bits are at the top and it will require pointing at SWT in order to work.) Thanks for any and all help. As a work around, I'm thinking about swapping controls between prints to see if that helps, but I'd rather not. import org.eclipse.swt.SWT; import org.eclipse.swt.custom.StackLayout; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.graphics.Image; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Label; import org.eclipse.swt.widgets.Shell; public class SWTImagePrintTest { private Composite stack; private StackLayout layout; private Label lblFlip; private Label lblFlop; private boolean flip = true; private Button buttonFlop; private Button buttonPrint; /** * Prints the control into an image * * @param control */ protected void print(Control control) { Image image = new Image(control.getDisplay(), control.getBounds()); GC gc = new GC(image); try { // As soon as this code is called, calling "layout" on the controls // causes them to disappear. control.print(gc); } finally { gc.dispose(); } } /** * Swaps the controls in the stack */ private void flipFlop() { if (flip) { flip = false; layout.topControl = lblFlop; buttonFlop.setText("flop"); stack.layout(); } else { flip = true; layout.topControl = lblFlip; buttonFlop.setText("flip"); stack.layout(); } } private void createContents(Shell shell) { shell.setLayout(new GridLayout(2, true)); stack = new Composite(shell, SWT.NONE); GridData gdStack = new GridData(GridData.FILL_BOTH); gdStack.horizontalSpan = 2; stack.setLayoutData(gdStack); layout = new StackLayout(); stack.setLayout(layout); lblFlip = new Label(stack, SWT.BOLD); lblFlip.setBackground(Display.getCurrent().getSystemColor( SWT.COLOR_CYAN)); lblFlip.setText("FlIp"); lblFlop = new Label(stack, SWT.NONE); lblFlop.setBackground(Display.getCurrent().getSystemColor( SWT.COLOR_BLUE)); lblFlop.setText("fLoP"); layout.topControl = lblFlip; stack.layout(); buttonFlop = new Button(shell, SWT.FLAT); buttonFlop.setText("Flip"); GridData gdFlip = new GridData(); gdFlip.horizontalAlignment = SWT.RIGHT; buttonFlop.setLayoutData(gdFlip); buttonFlop.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { flipFlop(); } }); buttonPrint = new Button(shell, SWT.FLAT); buttonPrint.setText("Print"); GridData gdPrint = new GridData(); gdPrint.horizontalAlignment = SWT.LEFT; buttonPrint.setLayoutData(gdPrint); buttonPrint.addSelectionListener(new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { print(lblFlip); print(lblFlop); } }); } /** * @param args */ public static void main(String[] args) { Shell shell = new Shell(); shell.setText("Slider Test"); shell.setSize(new Point(800, 600)); shell.setLayout(new GridLayout()); SWTImagePrintTest tt = new SWTImagePrintTest(); tt.createContents(shell); shell.open(); Display display = Display.getDefault(); while (shell.isDisposed() == false) { if (display.readAndDispatch() == false) { display.sleep(); } } display.dispose(); } }

    Read the article

  • adjust selected File to FileFilter in a JFileChooser

    - by amarillion
    I'm writing a diagram editor in java. This app has the option to export to various standard image formats such as .jpg, .png etc. When the user clicks File-Export, you get a JFileChooser which has a number of FileFilters in it, for .jpg, .png etc. Now here is my question: Is there a way to have the extension of the default adjust to the selected file filter? E.g. if the document is named "lolcat" then the default option should be "lolcat.png" when the png filter is selected, and when the user selects the jpg file filter, the default should change to "lolcat.jpg" automatically. Is this possible? How can I do it? edit: Based on the answer below, I wrote some code. But it doesn't quite work yet. I've added a propertyChangeListener to the FILE_FILTER_CHANGED_PROPERTY, but it seems that within this method getSelectedFile() returns null. Here is the code. package nl.helixsoft; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.beans.PropertyChangeEvent; import java.beans.PropertyChangeListener; import java.io.File; import java.util.ArrayList; import java.util.List; import javax.swing.JButton; import javax.swing.JFileChooser; import javax.swing.JFrame; import javax.swing.filechooser.FileFilter; public class JFileChooserTest { public class SimpleFileFilter extends FileFilter { private String desc; private List<String> extensions; private boolean showDirectories; /** * @param name example: "Data files" * @param glob example: "*.txt|*.csv" */ public SimpleFileFilter (String name, String globs) { extensions = new ArrayList<String>(); for (String glob : globs.split("\\|")) { if (!glob.startsWith("*.")) throw new IllegalArgumentException("expected list of globs like \"*.txt|*.csv\""); // cut off "*" // store only lower case (make comparison case insensitive) extensions.add (glob.substring(1).toLowerCase()); } desc = name + " (" + globs + ")"; } public SimpleFileFilter(String name, String globs, boolean showDirectories) { this(name, globs); this.showDirectories = showDirectories; } @Override public boolean accept(File file) { if(showDirectories && file.isDirectory()) { return true; } String fileName = file.toString().toLowerCase(); for (String extension : extensions) { if (fileName.endsWith (extension)) { return true; } } return false; } @Override public String getDescription() { return desc; } /** * @return includes '.' */ public String getFirstExtension() { return extensions.get(0); } } void export() { String documentTitle = "lolcat"; final JFileChooser jfc = new JFileChooser(); jfc.setDialogTitle("Export"); jfc.setDialogType(JFileChooser.SAVE_DIALOG); jfc.setSelectedFile(new File (documentTitle)); jfc.addChoosableFileFilter(new SimpleFileFilter("JPEG", "*.jpg")); jfc.addChoosableFileFilter(new SimpleFileFilter("PNG", "*.png")); jfc.addPropertyChangeListener(JFileChooser.FILE_FILTER_CHANGED_PROPERTY, new PropertyChangeListener() { public void propertyChange(PropertyChangeEvent arg0) { System.out.println ("Property changed"); String extold = null; String extnew = null; if (arg0.getOldValue() == null || !(arg0.getOldValue() instanceof SimpleFileFilter)) return; if (arg0.getNewValue() == null || !(arg0.getNewValue() instanceof SimpleFileFilter)) return; SimpleFileFilter oldValue = ((SimpleFileFilter)arg0.getOldValue()); SimpleFileFilter newValue = ((SimpleFileFilter)arg0.getNewValue()); extold = oldValue.getFirstExtension(); extnew = newValue.getFirstExtension(); String filename = "" + jfc.getSelectedFile(); System.out.println ("file: " + filename + " old: " + extold + ", new: " + extnew); if (filename.endsWith(extold)) { filename.replace(extold, extnew); } else { filename += extnew; } jfc.setSelectedFile(new File (filename)); } }); jfc.showDialog(frame, "export"); } JFrame frame; void run() { frame = new JFrame(); JButton btn = new JButton ("export"); frame.add (btn); btn.addActionListener (new ActionListener() { public void actionPerformed(ActionEvent ae) { export(); } }); frame.setSize (300, 300); frame.pack(); frame.setVisible(true); } public static void main(String[] args) { javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { JFileChooserTest x = new JFileChooserTest(); x.run(); } }); } }

    Read the article

  • Why is this default template parameter not allowed?

    - by Matt Joiner
    I have the following class: template <typename Type = void> class AlignedMemory { public: AlignedMemory(size_t alignment, size_t size) : memptr_(0) { int iret(posix_memalign((void **)&memptr_, alignment, size)); if (iret) throw system_error("posix_memalign"); } virtual ~AlignedMemory() { free(memptr_); } operator Type *() const { return memptr_; } Type *operator->() const { return memptr_; } //operator Type &() { return *memptr_; } //Type &operator[](size_t index) const; private: Type *memptr_; }; And attempt to instantiate an automatic variable like this: AlignedMemory blah(512, 512); This gives the following error: src/cpfs/entry.cpp:438: error: missing template arguments before ‘buf’ What am I doing wrong? Is void not an allowed default parameter?

    Read the article

  • Are delegates copied during assignment to an event?

    - by Sir Psycho
    Hi, The following code seems to execute the FileRetrieved event more than once. I thought delegates were a reference type. I was expecting this to execute once. I'm going to take a guess and say that the reference is being passed by value, therefore copied but I don't like guesswork :-) public delegate void DirListEvent<T>(T dirItem); void Main() { DirListEvent<string> printFilename = s => { Console.WriteLine (s); }; var obj = new DirectoryLister(); obj.FileRetrieved += printFilename; obj.FileRetrieved += printFilename; obj.GetDirListing(); } public class DirectoryLister { public event DirListEvent<string> FileRetrieved; public DirectoryLister() { FileRetrieved += delegate {}; } public void GetDirListing() { foreach (var file in Directory.GetFiles(@"C:\")) { FileRetrieved(file); } } }

    Read the article

  • Unit Testing functions within repository interfaces - ASP.net MVC3 & Moq

    - by RawryLions
    I'm getting into writing unit testing and have implemented a nice repository pattern/moq to allow me to test my functions without using "real" data. So far so good.. However.. In my repository interface for "Posts" IPostRepository I have a function: Post getPostByID(int id); I want to be able to test this from my Test class but cannot work out how. So far I am using this pattern for my tests: [SetUp] public void Setup() { mock = new Mock<IPostRepository>(); } [Test] public void someTest() { populate(10); //This populates the mock with 10 fake entries //do test here } In my function "someTest" I want to be able to call/test the function GetPostById. I can find the function with mock.object.getpostbyid but the "object" is null. Any help would be appreciated :) iPostRepository: public interface IPostRepository { IQueryable<Post> Posts {get;} void SavePost(Post post); Post getPostByID(int id); }

    Read the article

  • Placement new in gcc

    - by Roman Prikhodchenko
    I need to find a workaround for a bug with placement new in g++. I now it was fixed in gcc-4.3 but I have to support versions 4.2 and 4.1. For example, following code compiles with an error "error: no matching function for call to 'operator new(long unsigned int, void*&)" template<class T, template<typename> class Alloc> inline void* type_ctor() { Alloc<T> a; void* p = a.allocate(1); new(p) T; return p; } ..... type_ctor<A, NewAllocator >();

    Read the article

  • Java anonymous class efficiency implications

    - by Po
    Is there any difference in efficiency (e.g. execution time, code size, etc.) between these two ways of doing things? Below are contrived examples that create objects and do nothing, but my actual scenarios may be creating new Threads, Listeners, etc. Assume the following pieces of code happen in a loop so that it might make a difference. Using anonymous objects: void doSomething() { for (/* Assume some loop */) { final Object obj1, obj2; // some free variables IWorker anonymousWorker = new IWorker() { doWork() { // do things that refer to obj1 and obj2 } }; } } Defining a class first: void doSomething() { for (/* Assume some loop */) { Object obj1, obj2; IWorker worker = new Worker(obj1, obj2); } } static class Worker implements IWorker { private Object obj1, obj2; public CustomObject(Object obj1, Object obj2) {/* blah blah */} @Override public void doWork() {} }; Thank you :)

    Read the article

  • Name of several objects that have the same type

    - by Tomek Tarczynski
    Lets assume we have a class car. How would You name parameters of function that takes two different cars? void Race(Car first, Car second); or maybe void Race(Car car1, Car car2); The same situation with function that takes car and list of cars as a parameters. I'm used to name 'cars' for list of cars, so it is inconvenient to use names like: void Race(Car car, List<Car> cars); Any suggestions about names?

    Read the article

  • Java multi Generic collection parameters complie error

    - by Geln Yang
    Hi, So strange!Please have a look the code first: public class A { } public class B extends A { } public class C extends A { } public class TestMain { public <T extends A> void test(T a, T b) { } public <T extends A> void test(List<T> a, List<T> b) { } public static void main(String[] args) { new TestMain().test(new B(), new C()); new TestMain().test(new ArrayList<B>(), new ArrayList<C>()); } } The statement "new TestMain().test(new ArrayList(), new ArrayList())" get a "Bound mismatch" compile error, while "new TestMain().test(new B(), new C())" is compiled ok. Bound mismatch: The generic method test(T, T) of type TestMain is not applicable for the arguments (ArrayList, ArrayList). The inferred type ArrayList is not a valid substitute for the bounded parameter It seems the type of the second generic List parameter is limited by the Type of the first.Is it a feature or a bug of the compile program? ps, jdk:1.6,IDE:Eclipse 3.5.1

    Read the article

  • How to make this code compile?

    - by skydoor
    // File: foo.c static int var; void foo() { var++; } // end of file foo.c // File bar.c: static int var; void bar() { var++; } // end of file bar.c // file main.c static int var; void main() { foo(); bar(); printf("%d", var); } // end of file main.c Question: Will the above program compile ? If so what will be the result ? I tested the code and found it couldn't be compiled. I try to use extern in main.c to use the function foo() and bar() but it still couldn't be compiled.

    Read the article

  • Completion block not being called. How to check validity?

    - by HCHogan
    I have this method which takes a block, but that block isn't always called. See the method: - (void)updateWithCompletion:(void (^)(void))completion { [MYObject myMethodWithCompletion:^(NSArray *array, NSError *error) { if (error) { NSLog(@"%s, ERROR not nil", __FUNCTION__); completion(); return; } NSLog(@"%s, calling completion %d", __FUNCTION__, &completion); completion(); NSLog(@"%s, finished completion", __FUNCTION__); }]; } I have some more NSLogs inside completion. Sometimes this program counter just blows right past the call to completion() in the code above. I don't see why this would be as the calling code always passes a literal block of code as input. If you're curious of the output of the line containing the addressof operator, it's always something different, but never 0 or nil. What would cause completion not to be executed?

    Read the article

  • Can't resolve CalledFromWrongThreadException with Handler

    - by michel
    I will try to keep it simple: In my main activity I make a handler: public class ARViewer extends ARDisplayActivity { public final MHandler mHandler = new MHandler(this); public void onCreate(Bundle savedInstanceState) { ... The class MHandler: public final class MHandler extends Handler{ //main activity private ARViewer arnv; public MHandler(ARViewer arnv){ this.arnv = arnv; } @Override public void handleMessage(Message msg) { ... case H_RR : arnv.setContentView(R.layout.routeplanner); break; ... super.handleMessage(msg); } } But if I call the handleMessage method from a callback function in a other Class, definitely from a other thread, I still get the exception message: CalledFromWrongThreadException (Only the original thread that created a view hierarchy can touch its views) : public void rFound(Route route) { Message msg = new Message(); msg.what = MHandler.H_RR; ARViewer.arnv.mHandler.handleMessage(msg); }

    Read the article

  • two threads acting on the same runnable

    - by Eslam
    Given: public class Thread1 { int x = 0; public class Runner implements Runnable { public void run() { int current = 0; for (int i = 0; i < 4; i++) { current = x; System.out.print(current + " "); x = current + 2; } } } public void go() { Runnable r1 = new Runner(); new Thread(r1).start(); new Thread(r1).start(); } public static void main(String[] args) { new Thread1().go(); } } Which two are possible results? (Choose two) A. 0, 2, 4, 4, 6, 8, 10, 6, B. 0, 2, 4, 6, 8, 10, 2, 4, C. 0, 2, 4, 6, 8, 10, 12, 14, D. 0, 0, 2, 2, 4, 4, 6, 6, 8, 8, 10, 10, 12, 12, 14, 14, E. 0, 2, 4, 6, 8, 10, 12, 14, 0, 2, 4, 6, 8, 10, 12, 14, i chosed A,B but i'm not certain is those is the true or not.

    Read the article

  • i cannot set the title for my navigationBar

    - by Brionac
    here's my problem. i couldn't set the name for my navigationBar.. below are some i have tried but to no avail. (void)viewDidLload { [super viewDidLoad]; self.title = @"Food"; } (void)viewDidLload { [super viewDidLoad]; [self.setTitle:@"Food"]; } (void)viewDidLload { [super viewDidLoad]; MyTableViewController *myTableViewController = [[MyTableViewController alloc] init]; myTableViewController = @"Food"; } any kind soul?

    Read the article

  • Android EditText and addTextChangedListener

    - by Alex
    im currently porting a database manager to android and due to performance reasons i like to update only propertys that have been modified. Im trying to do this with the addTextChangedListener in order to add modified entrys to a List, but my Program never enters any of its methods. EditText Et = (EditText) Editors.get(Prop.Name); Et.addTextChangedListener(new TextWatcher() { @Override public void afterTextChanged(Editable s) { // TODO Auto-generated method stub } @Override public void beforeTextChanged(CharSequence s, int start, int count, int after) { // TODO Auto-generated method stub } @Override public void onTextChanged(CharSequence s, int start, int before, int count) { // TODO Auto-generated method stub if(Prop.GetType() == Property.PROPTYPE.num) { float f = Float.parseFloat(s.toString()); Prop.FromString(f); } else { Prop.FromString(s.toString()); } propertiesToUpdate.add(Prop); }); Et.setText(Prop.ToString());

    Read the article

  • Memory read/write access efficiency

    - by wolfPack88
    I've heard conflicting information from different sources, and I'm not really sure which one to believe. As such, I'll post what I understand and ask for corrections. Let's say I want to use a 2D matrix. There are three ways that I can do this (at least that I know of). 1: int i; char **matrix; matrix = malloc(50 * sizeof(char *)); for(i = 0; i < 50; i++) matrix[i] = malloc(50); 2: int i; int rowSize = 50; int pointerSize = 50 * sizeof(char *); int dataSize = 50 * 50; char **matrix; matrix = malloc(dataSize + pointerSize); char *pData = matrix + pointerSize - rowSize; for(i = 0; i < 50; i++) { pData += rowSize; matrix[i] = pData; } 3: //instead of accessing matrix[i][j] here, we would access matrix[i * 50 + j] char *matrix = malloc(50 * 50); In terms of memory usage, my understanding is that 3 is the most efficient, 2 is next, and 1 is least efficient, for the reasons below: 3: There is only one pointer and one allocation, and therefore, minimal overhead. 2: Once again, there is only one allocation, but there are now 51 pointers. This means there is 50 * sizeof(char *) more overhead. 1: There are 51 allocations and 51 pointers, causing the most overhead of all options. In terms of performance, once again my understanding is that 3 is the most efficient, 2 is next, and 1 is least efficient. Reasons being: 3: Only one memory access is needed. We will have to do a multiplication and an addition as opposed to two additions (as in the case of a pointer to a pointer), but memory access is slow enough that this doesn't matter. 2: We need two memory accesses; once to get a char *, and then to the appropriate char. Only two additions are performed here (once to get to the correct char * pointer from the original memory location, and once to get to the correct char variable from wherever the char * points to), so multiplication (which is slower than addition) is not required. However, on modern CPUs, multiplication is faster than memory access, so this point is moot. 1: Same issues as 2, but now the memory isn't contiguous. This causes cache misses and extra page table lookups, making it the least efficient of the lot. First and foremost: Is this correct? Second: Is there an option 4 that I am missing that would be even more efficient?

    Read the article

  • Why do I get a nullpointerexception at line ds.getPort in class L1?

    - by Fred
    import java.awt.; import java.awt.event.; import javax.swing.; import java.io.; import java.net.; import java.util.; public class Draw extends JFrame { /* * Socket stuff */ static String host; static int port; static int localport; DatagramSocket ds; Socket socket; Draw d; Paper p = new Paper(ds); public Draw(int localport, String host, int port) { d = this; this.localport = localport; this.host = host; this.port = port; try { ds = new DatagramSocket(localport); InetAddress ia = InetAddress.getByName(host); System.out.println("Attempting to connect DatagramSocket. Local port " + localport + " , foreign host " + host + ", foreign port " + port + "..."); ds.connect(ia, port); System.out.println("Success, ds.localport: " + ds.getLocalPort() + ", ds.port: " + ds.getPort() + ", address: " + ds.getInetAddress()); Reciever r = new Reciever(ds); r.start(); } catch (Exception e) { e.printStackTrace(); } setDefaultCloseOperation(EXIT_ON_CLOSE); getContentPane().add(p, BorderLayout.CENTER); setSize(640, 480); setVisible(true); } public static void main(String[] args) { int x = 0; for (String s : args){ if (x==0){ localport = Integer.parseInt(s); x++; } else if (x==1){ host = s; x++; } else if (x==2){ port = Integer.parseInt(s); } } Draw d = new Draw(localport, host, port); } } class Paper extends JPanel { DatagramSocket ds; private HashSet hs = new HashSet(); public Paper(DatagramSocket ds) { this.ds=ds; setBackground(Color.white); addMouseListener(new L1(ds)); addMouseMotionListener(new L2()); } public void paintComponent(Graphics g) { super.paintComponent(g); g.setColor(Color.black); Iterator i = hs.iterator(); while(i.hasNext()) { Point p = (Point)i.next(); g.fillOval(p.x, p.y, 2, 2); } } private void addPoint(Point p) { hs.add(p); repaint(); } class L1 extends MouseAdapter { DatagramSocket ds; public L1(DatagramSocket ds){ this.ds=ds; } public void mousePressed(MouseEvent me) { addPoint(me.getPoint()); Point p = me.getPoint(); String message = Integer.toString(p.x) + " " + Integer.toString(p.y); System.out.println(message); try{ byte[] data = message.getBytes("UTF-8"); //InetAddress ia = InetAddress.getByName(ds.host); String convertedMessage = new String(data, "UTF-8"); System.out.println("The converted string is " + convertedMessage); DatagramPacket dp = new DatagramPacket(data, data.length); System.out.println(ds.getPort()); //System.out.println(message); //System.out.println(ds.toString()); //ds.send(dp); /*System.out.println("2Sending a packet containing data: " +data +" to " + ia + ":" + d.port + "...");*/ } catch (Exception e){ e.printStackTrace(); } } } class L2 extends MouseMotionAdapter { public void mouseDragged(MouseEvent me) { addPoint(me.getPoint()); Point p = me.getPoint(); String message = Integer.toString(p.x) + " " + Integer.toString(p.y); //System.out.println(message); } } } class Reciever extends Thread{ DatagramSocket ds; byte[] buffer; Reciever(DatagramSocket ds){ this.ds = ds; buffer = new byte[65507]; } public void run(){ try { DatagramPacket packet = new DatagramPacket(buffer, buffer.length); while(true){ try { ds.receive(packet); String s = new String(packet.getData()); System.out.println(s); } catch (Exception e) { e.printStackTrace(); } } } catch (Exception e) { e.printStackTrace(); } } }

    Read the article

  • The Cleanest Reset for ARM Processor

    - by waffleman
    Lately, I've been cleaning up some some C code that runs on an ARM7 controller. In some situations (upgrade, fatal error, etc...) the program will perform a reset. Presently it just jumps to 0 and assumes that the start-up code will reinitialize everything correctly. It got me to thinking about what would be the best procedure a la "Leave No Trace" for an ARM reset. Here is my first crack at it: void Reset(void) { /* Disable interrupts */ __disable_interrupts(); /* Reset peripherals, externals and processor */ AT91C_BASE_RSTC->RSTC_RCR = AT91C_RSTC_KEY | AT91C_RSTC_PERRST | AT91C_RSTC_EXTRST| AT91C_RSTC_PROCRST; while(AT91C_BASE_RSTC->RSTC_RSR & AT91C_RSTC_SRCMP); /* Jump to the reset vector */ (*(void(*)())0)(); } Anything I haven't considered?

    Read the article

< Previous Page | 142 143 144 145 146 147 148 149 150 151 152 153  | Next Page >