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Search found 52959 results on 2119 pages for 'type library'.

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  • Bizarre static_cast trick?

    - by Rob
    While perusing the Qt source code I came across this gem: template <class T> inline T qgraphicsitem_cast(const QGraphicsItem *item) { return int(static_cast<T>(0)->Type) == int(QGraphicsItem::Type) || (item && int(static_cast<T>(0)->Type) == item->type()) ? static_cast<T>(item) : 0; } Notice the static_cast<T>(0)->Type? I've been using C++ for many years but have never seen 0 being used in a static_cast before. What is this code doing and is it safe? Background: If you derive from QGraphicsItem you are meant to declare an unique enum value called Type that and implement a virtual function called type that returns it, e.g.: class Item : public QGraphicsItem { public: enum { Type = MAGIC_NUMBER }; int type() const { return Type; } ... }; You can then do this: QGraphicsItem* item = new Item; ... Item* derivedItem = qgraphicsitem_cast<Item*>(item); This will probably help explain what that static_cast is trying to do.

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  • (Java) Get value of string loaded into dynamic-type object?

    - by Michael
    I'm very new to Java (~10 days), so my code is probably pretty bad, but here's what I've got: ArgsDataHolder argsData = new ArgsDataHolder(); // a class that holds two // ArrayList's where each element // representing key/value args Class thisArgClass; String thisArgString; Object thisArg; for(int i=2; i< argsString.length; i++) { thisToken = argsString[i]; thisArgClassString = getClassStringFromToken(thisToken).toLowerCase(); System.out.println("thisArgClassString: " + thisArgClassString); thisArgClass = getClassFromClassString(thisArgClassString); // find closing tag; concatenate middle Integer j = new Integer(i+1); thisArgString = getArgValue(argsString, j, "</" + thisArgClassString + ">"); thisArg = thisArgClass.newInstance(); thisArg = thisArgClass.valueOf(thisArgString); argsData.append(thisArg, thisArgClass); } The user basically has to input a set of key/value arguments into the command prompt in this format: <class>value</class>, e.g. <int>62</int>. Using this example, thisArgClass would be equal to Integer.class, thisArgString would be a string that read "62", and thisArg would be an instance of Integer that is equal to 62. I tried thisArg.valueOf(thisArgString), but I guess valueOf(<String>) is only a method of certain subclasses of Object. For whatever reason, I can't seem to be able to cast thisArg to thisArgClass (like so: thisArg = (thisArgClass)thisArgClass.newInstance();, at which point valueOf(<String>) should become accessible. There's got to be a nice, clean way of doing this, but it is beyond my abilities at this point. How can I get the value of the string loaded into a dynamically-typed object (Integer, Long, Float, Double, String, Character, Boolean, etc.)? Or am I just overthinking this, and Java will do the conversion for me? :confused:

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  • Encoding GBK2312 Condundrum

    - by user792271
    I am an amateur coder and I have a small problem. My goal is to have one text input with two buttons. The first button uses a bit of Javascript called SundayMorning to translate the text (to Chinese) The second button submits the text to a URL. The URl requires that Chinese text be encoded it in GBK2312 character set. I have duct taped together various found code to the result I have now. Due to the finicky behavior of the SundayMorning Javascript, my solution is to have two input boxes, the second of which I will hide. Right now, this doesn't work: I am unable to encode the Chinese in GBK2312, no matter what I try. BONUS CONUNDRUM: The second box copies my input letter by letter as I type, but does not copy the Chinese translation that the Javascript returns. Sorry for my janky amateur code. I defer to those more clever, if you have any kind suggestions. <head> <meta http-equiv="Content-Type" content="text/html; charset=GB2312" /> <script type='text/javascript' Src='https://ajax.googleapis.com/ajax/libs/jquery/1.6.1/jquery.min.js'> </script> ///THIS JS TRANSLATES THE TEXT INLINE <script type="text/javascript" src="jquery.sundaymorning.js"> </script> <script type="text/javascript"> $(function() { $('#example3').sundayMorningReset(); $('#example3 input[type=image]').click(function(evt) { $.sundayMorning( $('#example3 input[type=text]').val(),{source:'en', destination:'ZH', menuLeft:evt.pageX, menuTop:evt.pageY},function(response) {$('#example3 input[type=text]').val(response.translation);});});}); </script> /// ///THIS PUTS THE CONTENT OF THE TRANSLATION BOX INTO THE SUBMISSION BOX <script type="text/javascript"> $(document).ready(function(){ var $url = $("#url"); $("#track").keyup(function() { $url.val(this.value);}); $("#track").blur(function() { $url.val(this.value);});}); </script> ///THIS PUTS THE CONTENT OF THE SUBMISSION INSIDE A URL <SCRIPT type="text/javascript"> function goToPage(url) { var initial = "http://example.com/"; var extension = ".html"; document.something.action=initial+url+extension; } </SCRIPT> </head> <body> <div id="featured"> <div id="example3"> <input type="text" name="track" id="track" value="" class="box"onkeydown="javascript:if (event.which || event.keyCode){if ((event.which == 13) || (event.keyCode == 13)) {document.getElementById('mama').click();}};"/> <input type="image" src="http://taobaofieldguide.com/images/orange-translate-button.png" id="searchsubmit" value="Translate" class="btn" /> </div> <FORM name="something" method="post" onsubmit="goToPage(this.url.value);"> <input type="text" id="url";> <INPUT type="submit" id="mama" value="GO" > </FORM> </div> </body>

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  • How do I remove a control if not a specific type?

    - by joek1975
    I have a control that I need to restrict the types of child controls that it can contain during design time (dragging a new control onto an existing control on the form designer). I tried to do this by overriding the OnControlAdded event: Protected Overrides Sub OnControlAdded(ByVal e As System.Windows.Forms.ControlEventArgs) MyBase.OnControlAdded(e) If e.Control.GetType() IsNot GetType(ExpandablePanel) Then MsgBox("You can only add the ExpandablePanel control to the TaskPane.", MsgBoxStyle.Exclamation Or MsgBoxStyle.OkOnly, "TaskPane") Controls.Remove(e.Control) End If End Sub This seems to work, however I get an error message from Visual Studio immediately after the control is removed: 'child' is not a child control of this parent. What does this mean? How can I accomplish this without errors occurring?

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  • Django date filter: how come the format used is different from the one in datetime library?

    - by sebpiq
    For formatting a date using date filter you must use the following format : {{ my_date|date:"Y-m-d" }} If you use strftime from the standard datetime, you have to use the following : my_date.strftime("%Y-%m-%d") So my question is ... isn't it ugly (I guess it is because of the % that is used also for tags, and therefore is escaped or something) ? But that's not the main question ... I would like to use the same DATE_FORMAT parametrized in settings.py all over the project, but it therefore seems that I cannot ! Is there a work around (for example a filter that removes the % after the date has been formatted like {{ my_date|date|dream_filter }}, because if I just use DATE_FORMAT = "%Y-%m-%d" I got something like %2001-%6-%12)?

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  • Is there a jQuery plugin for making a step-by-step type presentation?

    - by Earlz
    Hello, I was making a small thing in HTML and basically I have some "frames" like <div id="frame_1"> ... </div> <div id="frame_2"> ... </div> ... Basically what I want is for only one frame to be visible at one time and to navigate between frames easily with previous and next buttons (navigation by frame number a plus, but not required) Before I set out to write it myself I figured someone had already done it so has it been done?

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  • How to list library dependencies of a non-native binary?

    - by lvella
    When developing for native platform, I can use ldd to list all the shared libraries (.so files) a binary executable I build will try to load upon start-up. But when cross-compiling, I don't know how to get the same information. The ldd is not a normal binutils utility, like strip or ar, that can be built alongside gcc for cross compiling, but instead, it is a cryptic shell script that apparently can only run on native platform. So, using the cross-target binutils tools, is there any way to get a list of the dynamically linked dependency for of a foreign binary?

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  • QComboBox returns None Type . How to get Current Data ?

    - by vettipayyan
    I've implemented 2 QComboBoxes with one having items manually inserted every time and another one having items inserted with a list (I'm using Python ) But when i attempt to get the current value of Combobox , it returns None . I proceeded as specified in this question : I referred this i have provided wat i've coded ."command" and "option" are QComboBoxes ( Pardon me for bad style) Is there any mistake in Indexes ? self.command.insertItem(1,'Convert') self.command.insertItem(2,'Compose') self.command.insertItem(3,'Animate') self.option.insertItems(268,list) and retrieval : self.selected_com=self.command.itemData(self.command.currentIndex()) self.selected_opt=self.option.itemData(self.option.currentIndex())

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  • Can I use anything other than BIGINT as Primary Key data type in SQLite?

    - by weenet
    I was psyched about the possibility of using SQLite as a database solution during development so that I could focus on writing the code first and dynamically generating the db at runtime using NHibernate's ShemaExport functionality. However, I'm running into a few issues, not the least of which is that it seems that SQLite requires me to use Int64 for my primary keys (vs, say, Int32 or Guid). Is there any way around this?

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  • How (and if) to write a single-consumer queue using the task parallel library?

    - by Eric
    I've heard a bunch of podcasts recently about the TPL in .NET 4.0. Most of them describe background activities like downloading images or doing a computation, using tasks so that the work doesn't interfere with a GUI thread. Most of the code I work on has more of a multiple-producer / single-consumer flavor, where work items from multiple sources must be queued and then processed in order. One example would be logging, where log lines from multiple threads are sequentialized into a single queue for eventual writing to a file or database. All the records from any single source must remain in order, and records from the same moment in time should be "close" to each other in the eventual output. So multiple threads or tasks or whatever are all invoking a queuer: lock( _queue ) // or use a lock-free queue! { _queue.enqueue( some_work ); _queueSemaphore.Release(); } And a dedicated worker thread processes the queue: while( _queueSemaphore.WaitOne() ) { lock( _queue ) { some_work = _queue.dequeue(); } deal_with( some_work ); } It's always seemed reasonable to dedicate a worker thread for the consumer side of these tasks. Should I write future programs using some construct from the TPL instead? Which one? Why?

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  • Doing a global count of an object type (like Users), best practice?

    - by user246114
    Hi, I know keeping global counters is frowned upon in app engine. I am interested in getting some stats though, like once every 24 hours. For example, I'd like to count the number of User objects in the system once every 24 hours. So how do we do this? Do we simply keep a set of admin tool functions which do something like: SELECT FROM com.me.project.server.User; and just see what the size of the returned List is? This is kind of a bummer because the datastore would have to deserialize every single User instance to create the returned list, right? I could optimize this possibly by asking for only the keys to be returned, so the whole User object doesn't have to be deserialized. Then again, a global counter for # of users probably would create too much contention, because there probably won't be hundreds of signups a minute for the service I'm creating. How should we go about doing this? Getting my total number of users once a day is probably a pretty typical operation? Thank you

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  • SWI-Prolog: how to load rdf triples using semweb/rdf_db library?

    - by Li Li
    Hi, I have a rdf file (file.trp) in n-triples format, where each line is: "subject predicate object ." I tried to use rdf_load in semweb/rdf_db to load it into memory, but failed. Here is what I tried: ?- rdf_load('file.trp'). ?- rdf_load('file.trp', [format(triples]). the manual says it supports xml and triples. But it only loads rdf xml files. How can I load such rdf triple file? Thanks, Li

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  • How to query a collection of inherited object for a particular object type in grails ?

    - by quilovnic
    Hi, I have a this model : class Question{ Set components static hasMany = [components: QuestionComponent] } class QuestionComponent{ static belongsTo = Question } class QuestionComponentStatus extends QuestionComponent{ } class QuestionComponentOther extends QuestionComponent{ } I want to get only QuestionComponentStatus from Set components : questionInstance.components. ? Thanks a lot

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