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  • html horizontal scrolling

    - by mp
    Hi, i have a simple css example, and i can't understand the behavior of one of my divs, when the horizontal scroll is displayed. so...when my browser window needs to display the horizontal scroll(when the window width is less than my div "content" width(1024px)), my div "footer" (that have the same "content's" parent and 100% width), seems to get an "extra blank space" on the right side. this space grows when I reduce the width of the window. any ideas about how can i get it off, or why it happens??thanks! heres my code: css: <style type="text/css"> html, body { height: 100%; width:100%; font-family:"Arial Black", Gadget, sans-serif; font-size:11px; font-variant:normal; } * { margin: 0; } .wrapper { min-height: 100%; height: auto !important; height: 100%; margin: 0 auto -4em; } #content{ width:1024px; margin:0px auto; background-color:#990; height:780px; } .footer, .push { height: 4em; width:100%; } #footer-content{ height:10px; background-color:#09F; width:100%; } </style> html: <body> <div class="wrapper"> <div id="content"> <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nullam scelerisque varius tortor vitae pretium. Quisque magna ipsum, accumsan sit amet pretium sed, iaculis feugiat nibh. Donec vitae dui eros, eu ultricies nulla. Morbi aliquet, nisi in tincidunt rutrum, nisl justo sagittis nisi, nec dignissim orci elit vitae tortor. </p> </div> <div class="push"></div> </div> <div class="footer" style="background-color:#900; width:100%;"> <div id="footer-content"></div> </div> </body>

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  • Calling/selecting variables (float valued) with user input in Python

    - by Jonathan Straus
    I've been working on a computational physics project (plotting related rates of chemical reactants with respect to eachother to show oscillatory behavior) with a fair amount of success. However, one of my simulations involves more than two active oscillating agents (five, in fact) which would obviously be unsuitable for any single visual plot... My scheme was hence to have the user select which two reactants they wanted plotted on the x-axis and y-axis respectively. I tried (foolishly) to convert string input values into the respective variable names, but I guess I need a radically different approach if any exist? If it helps clarify any, here is part of my code: def coupledBrusselator(A, B, t_trial,display_x,display_y): t = 0 t_step = .01 X = 0 Y = 0 E = 0 U = 0 V = 0 dX = (A) - (B+1)*(X) + (X**2)*(Y) dY = (B)*(X) - (X**2)*(Y) dE = -(E)*(U) - (X) dU = (U**2)*(V) -(E+1)*(U) - (B)*(X) dV = (E)*(U) - (U**2)*(V) array_t = [0] array_X = [0] array_Y = [0] array_U = [0] array_V = [0] while t <= t_trial: X_1 = X + (dX)*(t_step/2) Y_1 = Y + (dY)*(t_step/2) E_1 = E + (dE)*(t_step/2) U_1 = U + (dU)*(t_step/2) V_1 = V + (dV)*(t_step/2) dX_1 = (A) - (B+1)*(X_1) + (X_1**2)*(Y_1) dY_1 = (B)*(X_1) - (X_1**2)*(Y_1) dE_1 = -(E_1)*(U_1) - (X_1) dU_1 = (U_1**2)*(V_1) -(E_1+1)*(U_1) - (B)*(X_1) dV_1 = (E_1)*(U_1) - (U_1**2)*(V_1) X_2 = X + (dX_1)*(t_step/2) Y_2 = Y + (dY_1)*(t_step/2) E_2 = E + (dE_1)*(t_step/2) U_2 = U + (dU_1)*(t_step/2) V_2 = V + (dV_1)*(t_step/2) dX_2 = (A) - (B+1)*(X_2) + (X_2**2)*(Y_2) dY_2 = (B)*(X_2) - (X_2**2)*(Y_2) dE_2 = -(E_2)*(U_2) - (X_2) dU_2 = (U_2**2)*(V_2) -(E_2+1)*(U_2) - (B)*(X_2) dV_2 = (E_2)*(U_2) - (U_2**2)*(V_2) X_3 = X + (dX_2)*(t_step) Y_3 = Y + (dY_2)*(t_step) E_3 = E + (dE_2)*(t_step) U_3 = U + (dU_2)*(t_step) V_3 = V + (dV_2)*(t_step) dX_3 = (A) - (B+1)*(X_3) + (X_3**2)*(Y_3) dY_3 = (B)*(X_3) - (X_3**2)*(Y_3) dE_3 = -(E_3)*(U_3) - (X_3) dU_3 = (U_3**2)*(V_3) -(E_3+1)*(U_3) - (B)*(X_3) dV_3 = (E_3)*(U_3) - (U_3**2)*(V_3) X = X + ((dX + 2*dX_1 + 2*dX_2 + dX_3)/6) * t_step Y = Y + ((dX + 2*dY_1 + 2*dY_2 + dY_3)/6) * t_step E = E + ((dE + 2*dE_1 + 2*dE_2 + dE_3)/6) * t_step U = U + ((dU + 2*dU_1 + 2*dY_2 + dE_3)/6) * t_step V = V + ((dV + 2*dV_1 + 2*dV_2 + dE_3)/6) * t_step dX = (A) - (B+1)*(X) + (X**2)*(Y) dY = (B)*(X) - (X**2)*(Y) t_step = .01 / (1 + dX**2 + dY**2) ** .5 t = t + t_step array_X.append(X) array_Y.append(Y) array_E.append(E) array_U.append(U) array_V.append(V) array_t.append(t) where previously display_x = raw_input("Choose catalyst you wish to analyze in the phase/field diagrams (X, Y, E, U, or V) ") display_y = raw_input("Choose one other catalyst from list you wish to include in phase/field diagrams ") coupledBrusselator(A, B, t_trial, display_x, display_y) Thanks!

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  • How can give validation on custom registration form in drupal?

    - by Nitz
    Hey Friends, I have created custom registration form in drupal 6. i have used changed the behavior of the drupal registration page by adding this code in themes. template file function earthen_theme($existing, $type, $theme, $path) { return array( // tell Drupal what template to use for the user register form 'user_register' => array( 'arguments' => array('form' => NULL), 'template' => 'user_register', // this is the name of the template ), ); } and my user_register.tpl.php file is looking like this... //php tag starts from here $forms['access'] = array( '#type' = 'fieldset', '#title' = t('Access log settings'), ); $form['my_text_field']=array( '#type' = 'textfield', '#default_value' = $node-title, '#size' = 30, '#maxlength' = 50, '#required' = TRUE ); <div id="registration_form"><br> <div class="field"> <?php print drupal_render($form['my_text_field']); // prints the username field ?> </div> <div class="field"> <?php print drupal_render($form['account']['name']); // prints the username field ?> </div> <div class="field"> <?php print drupal_render($form['account']['pass']); // print the password field ?> </div> <div class="field"> <?php print drupal_render($form['account']['email']); // print the password field ?> </div> <div class="field"> <?php print drupal_render($form['submit']); // print the submit button ?> </div> </div> How to make validation on "my_text_field" which is custmized. and exactly i want that as soon as user click on my_text_field then datetime picker should be open and whichever date user select, that date should be value in my_text_field. so guys help. Thanks in advance, nitish Panchjanya Corporation

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  • Accessing different connection strings at runtime in ASP.NET MVC 1

    - by Neil T.
    I'm trying to implement integration testing in my ASP.NET MVC 1.0 solution. The technologies in use are LINQ-to-SQL, NUnit and WatiN. I recently discovered a pattern that will allow me to create a testing version of the database on the fly without modifying the development version of the database. I needed this behavior in order to run my user interface tests in WatiN that may modify the database. The plan is to modify the connection string in the Web.config file, and pass that new connection string to the DataContext constructor. This way, I don't have to add routes or modify my URLs in order to perform the integration testing. I've set up the project so that the test setup can modify the connection string to point to the test database when the tests are running. The connection string is stored in web.config. The problem I'm having is that when I try to run the tests, I get a NullReferenceException when trying to access the HTTPContext. From everything that I have read so far, the HTTPContext is only available within the context of a controller. Here is the code for the property that is supposed to give me the reference to the Web.config file: private System.Configuration.Configuration WebConfig { get { ExeConfigurationFileMap fileMap = new ExeConfigurationFileMap(); // NullReferenceException occurs on this line. fileMap.ExeConfigFilename = HttpContext.Current.Server.MapPath("~\\web.config"); System.Configuration.Configuration config = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None); return config; } } Is there something that I am missing in order to make this work? Is there a better way to accomplish what I'm trying to achieve? UPDATE: I decided to abandon the modification of Web.config in lieu of a "request-scoped DataContext" pattern that I found here. From the looks of it, I believe it should give me the results I'm looking for. However, during the TextFixtureSetUp, I try to create a new copy of the database for testing purposes, and it fails silently. When I get to the tests, the repository still uses the production database connection string to load data.

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  • OpenGL suppresses exceptions in MFC dialog-based application

    - by Mikhail
    Hello. I have an MFC-driven dialog-based application created with MSVS2005. Here is my problem step by step. I have button on my dialog and corresponding click-handler with code like this: int* i = 0; *i = 3; I'm running debug version of program and when I click on the button, Visual Studio catches focus and alerts "Access violation writing location" exception, program cannot recover from the error and all I can do is to stop debugging. And this is the right behavior. Now I add some OpenGL initialization code in the OnInitDialog() method: HDC DC = GetDC(GetSafeHwnd()); static PIXELFORMATDESCRIPTOR pfd = { sizeof(PIXELFORMATDESCRIPTOR), // size of this pfd 1, // version number PFD_DRAW_TO_WINDOW | // support window PFD_SUPPORT_OPENGL | // support OpenGL PFD_DOUBLEBUFFER, // double buffered PFD_TYPE_RGBA, // RGBA type 24, // 24-bit color depth 0, 0, 0, 0, 0, 0, // color bits ignored 0, // no alpha buffer 0, // shift bit ignored 0, // no accumulation buffer 0, 0, 0, 0, // accum bits ignored 32, // 32-bit z-buffer 0, // no stencil buffer 0, // no auxiliary buffer PFD_MAIN_PLANE, // main layer 0, // reserved 0, 0, 0 // layer masks ignored }; int pixelformat = ChoosePixelFormat(DC, &pfd); SetPixelFormat(DC, pixelformat, &pfd); HGLRC hrc = wglCreateContext(DC); ASSERT(hrc != NULL); wglMakeCurrent(DC, hrc); Of course this is not exactly what I do, it is the simplified version of my code. Well now the strange things begin to happen: all initialization is fine, there are no errors in OnInitDialog(), but when I click the button... no exception is thrown. Nothing happens. At all. If I set a break-point at the *i = 3; and press F11 on it, the handler-function halts immediately and focus is returned to the application, which continue to work well. I can click button again and the same thing will happen. It seems like someone had handled occurred exception of access violation and silently returned execution into main application message-receiving cycle. If I comment the line wglMakeCurrent(DC, hrc);, all works fine as before, exception is thrown and Visual Studio catches it and shows window with error message and program must be terminated afterwards. I experience this problem under Windows 7 64-bit, NVIDIA GeForce 8800 with latest drivers (of 11.01.2010) available at website installed. My colleague has Windows Vista 32-bit and has no such problem - exception is thrown and application crashes in both cases. Well, hope good guys will help me :) PS The problem originally where posted under this topic.

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  • Why does SFINAE not apply to this?

    - by Simon Buchan
    I'm writing some simple point code while trying out Visual Studio 10 (Beta 2), and I've hit this code where I would expect SFINAE to kick in, but it seems not to: template<typename T> struct point { T x, y; point(T x, T y) : x(x), y(y) {} }; template<typename T, typename U> struct op_div { typedef decltype(T() / U()) type; }; template<typename T, typename U> point<typename op_div<T, U>::type> operator/(point<T> const& l, point<U> const& r) { return point<typename op_div<T, U>::type>(l.x / r.x, l.y / r.y); } template<typename T, typename U> point<typename op_div<T, U>::type> operator/(point<T> const& l, U const& r) { return point<typename op_div<T, U>::type>(l.x / r, l.y / r); } int main() { point<int>(0, 1) / point<float>(2, 3); } This gives error C2512: 'point<T>::point' : no appropriate default constructor available Given that it is a beta, I did a quick sanity check with the online comeau compiler, and it agrees with an identical error, so it seems this behavior is correct, but I can't see why. In this case some workarounds are to simply inline the decltype(T() / U()), to give the point class a default constructor, or to use decltype on the full result expression, but I got this error while trying to simplify an error I was getting with a version of op_div that did not require a default constructor*, so I would rather fix my understanding of C++ rather than to just do what works. Thanks! *: the original: template<typename T, typename U> struct op_div { static T t(); static U u(); typedef decltype(t() / u()) type; }; Which gives error C2784: 'point<op_div<T,U>::type> operator /(const point<T> &,const U &)' : could not deduce template argument for 'const point<T> &' from 'int', and also for the point<T> / point<U> overload.

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  • How does NameScope in WPF works ?

    - by Nicolas Dorier
    I'm having a strange behavior with NameScopes in WPF, I have created a CustomControl called FadingPopup which is a child class of Window with nothing special inside. <Window.Resources> <local:FadingPopup> <Button Name="prec" Content="ahah"></Button> <Button Content="{Binding ElementName=prec, Path=Content}"></Button> </local:FadingPopup> </Window.Resources> In this snippet, the binding doesn't work (always empty). If I move these buttons from the resources to the content of the window like this : <Window ...> <Button Name="prec" Content="ahah"></Button> <Button Content="{Binding ElementName=prec, Path=Content}"></Button> </Window> The binding works as expected. Now, I have tried a mix between these two snippets : <Window...> <Window.Resources> <local:FadingPopup> <Button Name="prec" Content="Haha"></Button> </local:FadingPopup> </Window.Resources> <Button Content="{Binding ElementName=prec, Path=Content}"></Button> </Window> It works as well. Apparently, if the button prec is in the resources it registers itself in the NameScope of the Window. BUT, it seems that the Binding tries to resolve ElementName with the NameScope of the FadingPopup (which is null), thus the binding doesn't work... My first snipped works well if I specify a NameScope in my class FadingPopup : static FadingPopup() { NameScope.NameScopeProperty.OverrideMetadata(typeof(FadingPopup), new PropertyMetadata(new NameScope())); } But I don't like this solution because I don't understand why, in the first snippet, prec is registered in the NameScope of Window, but ElementName is resolved with the NameScope of FadingGroup (which is null by default)... Does someone can explain to me what is going on ? Why my first snippet doesn't work, if I don't specify a default NameScope for FadingGroup ?

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  • How can I capture the keystroke that triggers "CellEndEdit" on a DataGridView in C#?

    - by Andy Stampor
    I have a DataGridView that is set to EditOnF2. I do some special processing of data in the CellEndEdit eventhandler that sets the value of the cell. I still want the functionality of the EditOnKeystrokeOrF2 of reverting to the original value when the Esc key is pressed. Unfortunately, at the CellEndEdit eventhandler, I don't see a way to tell what caused the CellEndEdit event to be fired. I only want to change the value of the cell if the Esc key is not pressed. How can I tell if it was or not? Edit: It is worth noting that the KeyDown event does not get fired when the cell is being edited, nor for the final ending keystroke. Edit2: I have tried the KeyPreview suggestion, but the form still does not capture the Escape key being pressed. Edit3: I've been experimenting with trying to get this working. I originally posted some of the following as a separate post, but feel it might be more relevant to include it here. I have a cell in a DataGridView that is now set to EditProgrammatically. To capture the keystroke that starts an edit, I am setting the cell.Value equal to the keystroke. However, this ruins the "Escape" functionality of the cell - when you press escape, instead of reverting to the original value, it reverts to the keystroke that I programmatically inserted into the cell. I believe that if I could set the "EditedFormattedValue" on a cell, this would be where I want to put my keystroke value, however this appears to be read only. How can I accomplish what I am attempting? An example to clarify: If the cell has a value of "54.3" in it, and I press the "9" key, it begins editing the cell and places a "9" there. If I hit Escape, instead of reverting to "54.3" it reverts to "9". What I want is for it to return to its original value of "54.3". So, I am trying to tackle this issue from both the beginning and the end. I think the real problem is that I am overwriting the original value and have no way to determine if I should revert it or not. Edit4: It looks like CellValidating might be worth using, but I am seeing strange behavior when I experiment with it. In a new project, I create the DataGridView and register for the various events and see that CellValidating is fired before the CellEndEdit. However, in my project where I am trying to get this to work, CellEndEdit is firing BEFORE CellValidating. Any ideas on what the difference might be?

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  • Postgresql: Implicit lock acquisition from foreign-key constraint evaluation

    - by fennec
    So, I'm being confused about foreign key constraint handling in Postgresql. (version 8.4.4, for what it's worth). We've got a couple of tables, mildly anonymized below: device: (id, blah, blah, blah, blah, blah x 50)… primary key on id whooooole bunch of other junk device_foo: (id, device_id, left, right) Foreign key (device_id) references device(id) on delete cascade; primary key on id btree index on 'left' and 'right' So I set out with two database windows to run some queries. db1> begin; lock table device in exclusive mode; db2> begin; update device_foo set left = left + 1; The db2 connection blocks. It seems odd to me that an update of the 'left' column on device_stuff should be affected by activity on the device table. But it is. In fact, if I go back to db1: db1> select * from device_stuff for update; *** deadlock occurs *** The pgsql log has the following: blah blah blah deadlock blah. CONTEXT: SQL statement "SELECT 1 FROM ONLY "public"."device" x WHERE "id" OPERATOR(pg_catalog.=) $1 FOR SHARE OF X: update device_foo set left = left + 1; I suppose I've got two issues: the first is that I don't understand the precise mechanism by which this sort of locking occurs. I have got a couple of useful queries to query pg_locks to see what sort of locks a statement invokes, but I haven't been able to observe this particular sort of locking when I run the update device_foo command in isolation. (Perhaps I'm doing something wrong, though.) I also can't find any documentation on the lock acquisition behavior of foreign-key constraint checks. All I have is a log message. Am I to infer from this that any change to a row will acquire an update lock on all the tables which it's foreign-keyed against? The second issue is that I'd like to find some way to make it not happen like that. I'm ending up with occasional deadlocks in the actual application. I'd like to be able to run big update statements that impact all rows on device_foo without acquiring a big lock on the device table. (There's a lot of access going on in the device table, and it's kind of an expensive lock to get.)

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  • Share a "deep link" from a Windows 8/WinRT application

    - by Dave Parker
    I have searched using many different terms and phrases, and waded through many pages of results, but I have (remarkably) not seen anyone else addressing, even asking, about, this issue. So here goes... Ultimate Goal: Allow a user viewing a content-based page (may contain both text and images) within a Windows Store app to share that content with someone else. Description I am working on taking a fair amount of content and making it available for browsing/navigating as a Windows 8/WinRT/Windows Store (we need a consistent name here) application. One of the desired features is to take advantage of the Share Charm, such that someone viewing a page could share that page with someone else. The ideal behavior is for the application to implement the Share Source contract which would share an email message that contained some explanatory text, a link to get the app from the Windows Store, and a "deep link" into the shared page in the application. Solutions Considered We had originally looked at just generating a PDF representation of the page, but there are very few external libraries that would work under WinRT, and having to include externally licensed code would be problematic as well. Writing our own PDF generation code would out of scope. We have also considered generating a Word document or PowerPoint slide using OpenXML, but again, we run up against the limitaions of WinRT. In this case, it is highly unlikely the OpenXML SDK is useable in a WinRT application. Another thought was to pre-generate all of the pages as .pdf files, store them as resources, and when the Share Charm is invoked, share the .pdf file associated with the current page. The problem here is the application will have at least 150 content pages, and depending on how we break the content down, up to over 600. This would likely cause serious bloat. Where We Are At Thus we have come to sharing URIs. From what I can tell, though, the "deep linking" feature is only intended for use on Secondary Tiles tied to your application. Another avenue I considered was registering a protocol like, "my-special-app:" with the OS and having it fire up the application but that would require HKCR registry access, which is outside the WinRT sandbox. If it matters, we are leaning towards an HTML/JS application, rather than XAML/C#, because the converted content will all be in HTML and the WebView control in WinRT is fairly limited. This decision is not yet final, though. Conclusion So, is this possible, and if so, how would it be done or where can I find documentation on it? Thanks, Dave Parker

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  • Excel UDF calculation should return 'original' value

    - by LeChe
    Hi all, I've been struggling with a VBA problem for a while now and I'll try to explain it as thoroughly as possible. I have created a VSTO plugin with my own RTD implementation that I am calling from my Excel sheets. To avoid having to use the full-fledged RTD syntax in the cells, I have created a UDF that hides that API from the sheet. The RTD server I created can be enabled and disabled through a button in a custom Ribbon component. The behavior I want to achieve is as follows: If the server is disabled and a reference to my function is entered in a cell, I want the cell to display Disabled If the server is disabled, but the function had been entered in a cell when it was enabled (and the cell thus displays a value), I want the cell to keep displaying that value If the server is enabled, I want the cell to display Loading Sounds easy enough. Here is an example of the - non functional - code: Public Function RetrieveData(id as Long) Dim result as String // This returns either 'Disabled' or 'Loading' result = Application.Worksheet.Function.RTD("SERVERNAME", "", id) RetrieveData = result If(result = "Disabled") Then // Obviously, this recurses (and fails), so that's not an option If(Not IsEmpty(Application.Caller.Value2)) Then // So does this RetrieveData = Application.Caller.Value2 End If End If End Function The function will be called in thousands of cells, so storing the 'original' values in another data structure would be a major overhead and I would like to avoid it. Also, the RTD server does not know the values, since it also does not keep a history of it, more or less for the same reason. I was thinking that there might be some way to exit the function which would force it to not change the displayed value, but so far I have been unable to find anything like that. Any ideas on how to solve this are greatly appreciated! Thanks, Che EDIT: By popular demand, some additional info on why I want to do all this: As I said, the function will be called in thousands of cells and the RTD server needs to retrieve quite a bit of information. This can be quite hard on both network and CPU. To allow the user to decide for himself whether he wants this load on his machine, he or she can disable the updates from the server. In that case, he or she should still be able to calculate the sheets with the values currently in the fields, yet no updates are pushed into them. Once new data is required, the server can be enabled and the fields will be updated. Again, since we are talking about quite a bit of data here, I would rather not store it somewhere in the sheet. Plus, the data should be usable even if the workbook is closed and loaded again.

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  • Unlocking a mutex from a different thread (C++)

    - by dan
    I'm using the C++ boost::thread library, which in my case means I'm using pthreads. Officially, a mutex must be unlocked from the same thread which locks it, and I want the effect of being able to lock in one thread and then unlock in another. There are many ways to accomplish this. One possibility would be to write a new mutex class which allows this behavior. For example: class inter_thread_mutex{ bool locked; boost::mutex mx; boost::condition_variable cv; public: void lock(){ boost::unique_lock<boost::mutex> lck(mx); while(locked) cv.wait(lck); locked=true; } void unlock(){ { boost::lock_guard<boost::mutex> lck(mx); if(!locked) error(); locked=false; } cv.notify_one(); } // bool try_lock(); void error(); etc. } I should point out that the above code doesn't guarantee FIFO access, since if one thread calls lock() while another calls unlock(), this first thread may acquire the lock ahead of other threads which are waiting. (Come to think of it, the boost::thread documentation doesn't appear to make any explicit scheduling guarantees for either mutexes or condition variables). But let's just ignore that (and any other bugs) for now. My question is, if I decide to go this route, would I be able to use such a mutex as a model for the boost Lockable concept. For example, would anything go wrong if I use a boost::unique_lock< inter_thread_mutex for RAII-style access, and then pass this lock to boost::condition_variable_any.wait(), etc. On one hand I don't see why not. On the other hand, "I don't see why not" is usually a very bad way of determining whether something will work. The reason I ask is that if it turns out that I have to write wrapper classes for RAII locks and condition variables and whatever else, then I'd rather just find some other way to achieve the same effect.

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  • Drawing text to <canvas> with @font-face does not work at the first time

    - by lemonedo
    Hi all, First try the test case please: http://lemon-factory.net/test/font-face-and-canvas.html I'm not good at English, so I made the test case to be self-explanatory. On the first click to the DRAW button, it will not draw text, or will draw with an incorrect typeface instead of the specified "PressStart", according to your browser. After then it works as expected. At the first time the text does not appear correctly in all browsers I've tested (Firefox, Google Chrome, Safari, Opera). Is it the standard behavior or something? Thank you. PS: Following is the code of the test case <!DOCTYPE html> <html> <head> <meta http-equiv=Content-Type content="text/html;charset=utf-8"> <title>@font-face and canvas</title> <style> @font-face { font-family: 'PressStart'; src: url('http://lemon-factory.net/css/fonts/prstart.ttf'); } canvas, pre { border: 1px solid #666; } pre { float: left; margin: .5em; padding: .5em; } </style> </head> <body> <div> <canvas id=canvas width=250 height=250> Your browser does not support the CANVAS element. Try the latest Firefox, Google Chrome, Safari or Opera. </canvas> <button>DRAW</button> </div> <pre id=style></pre> <pre id=script></pre> <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script> <script> var canvas = document.getElementById('canvas') var ctx = canvas.getContext('2d') var x = 30 var y = 10 function draw() { ctx.font = '12px PressStart' ctx.fillStyle = '#000' ctx.fillText('Hello, world!', x, y += 20) ctx.fillRect(x - 20, y - 10, 10, 10) } $('button').click(draw) $('pre#style').text($('style').text()) $('pre#script').text($('script').text()) </script> </body> </html>

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  • CLR 4.0 inlining policy? (maybe bug with MethodImplOptions.NoInlining)

    - by ControlFlow
    I've testing some new CLR 4.0 behavior in method inlining (cross-assembly inlining) and found some strage results: Assembly ClassLib.dll: using System.Diagnostics; using System; using System.Reflection; using System.Security; using System.Runtime.CompilerServices; namespace ClassLib { public static class A { static readonly MethodInfo GetExecuting = typeof(Assembly).GetMethod("GetExecutingAssembly"); public static Assembly Foo(out StackTrace stack) // 13 bytes { // explicit call to GetExecutingAssembly() stack = new StackTrace(); return Assembly.GetExecutingAssembly(); } public static Assembly Bar(out StackTrace stack) // 25 bytes { // reflection call to GetExecutingAssembly() stack = new StackTrace(); return (Assembly) GetExecuting.Invoke(null, null); } public static Assembly Baz(out StackTrace stack) // 9 bytes { stack = new StackTrace(); return null; } public static Assembly Bob(out StackTrace stack) // 13 bytes { // call of non-inlinable method! return SomeSecurityCriticalMethod(out stack); } [SecurityCritical, MethodImpl(MethodImplOptions.NoInlining)] static Assembly SomeSecurityCriticalMethod(out StackTrace stack) { stack = new StackTrace(); return Assembly.GetExecutingAssembly(); } } } Assembly ConsoleApp.exe using System; using ClassLib; using System.Diagnostics; class Program { static void Main() { Console.WriteLine("runtime: {0}", Environment.Version); StackTrace stack; Console.WriteLine("Foo: {0}\n{1}", A.Foo(out stack), stack); Console.WriteLine("Bar: {0}\n{1}", A.Bar(out stack), stack); Console.WriteLine("Baz: {0}\n{1}", A.Baz(out stack), stack); Console.WriteLine("Bob: {0}\n{1}", A.Bob(out stack), stack); } } Results: runtime: 4.0.30128.1 Foo: ClassLib, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null at ClassLib.A.Foo(StackTrace& stack) at Program.Main() Bar: ClassLib, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null at ClassLib.A.Bar(StackTrace& stack) at Program.Main() Baz: at Program.Main() Bob: ClassLib, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null at Program.Main() So questions are: Why JIT does not inlined Foo and Bar calls as Baz does? They are lower than 32 bytes of IL and are good candidates for inlining. Why JIT inlined call of Bob and inner call of SomeSecurityCriticalMethod that is marked with the [MethodImpl(MethodImplOptions.NoInlining)] attribute? Why GetExecutingAssembly returns a valid assembly when is called by inlined Baz and SomeSecurityCriticalMethod methods? I've expect that it performs the stack walk to detect the executing assembly, but stack will contains only Program.Main() call and no methods of ClassLib assenbly, to ConsoleApp should be returned.

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  • 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).

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  • Recommendations for a C++ polymorphic, seekable, binary I/O interface

    - by Trevor Robinson
    I've been using std::istream and ostream as a polymorphic interface for random-access binary I/O in C++, but it seems suboptimal in numerous ways: 64-bit seeks are non-portable and error-prone due to streampos/streamoff limitations; currently using boost/iostreams/positioning.hpp as a workaround, but it requires vigilance Missing operations such as truncating or extending a file (ala POSIX ftruncate) Inconsistency between concrete implementations; e.g. stringstream has independent get/put positions whereas filestream does not Inconsistency between platform implementations; e.g. behavior of seeking pass the end of a file or usage of failbit/badbit on errors Don't need all the formatting facilities of stream or possibly even the buffering of streambuf streambuf error reporting (i.e. exceptions vs. returning an error indicator) is supposedly implementation-dependent in practice I like the simplified interface provided by the Boost.Iostreams Device concept, but it's provided as function templates rather than a polymorphic class. (There is a device class, but it's not polymorphic and is just an implementation helper class not necessarily used by the supplied device implementations.) I'm primarily using large disk files, but I really want polymorphism so I can easily substitute alternate implementations (e.g. use stringstream instead of fstream for unit tests) without all the complexity and compile-time coupling of deep template instantiation. Does anyone have any recommendations of a standard approach to this? It seems like a common situation, so I don't want to invent my own interfaces unnecessarily. As an example, something like java.nio.FileChannel seems ideal. My best solution so far is to put a thin polymorphic layer on top of Boost.Iostreams devices. For example: class my_istream { public: virtual std::streampos seek(stream_offset off, std::ios_base::seekdir way) = 0; virtual std::streamsize read(char* s, std::streamsize n) = 0; virtual void close() = 0; }; template <class T> class boost_istream : public my_istream { public: boost_istream(const T& device) : m_device(device) { } virtual std::streampos seek(stream_offset off, std::ios_base::seekdir way) { return boost::iostreams::seek(m_device, off, way); } virtual std::streamsize read(char* s, std::streamsize n) { return boost::iostreams::read(m_device, s, n); } virtual void close() { boost::iostreams::close(m_device); } private: T m_device; };

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  • Foreign Key Relationships and "belongs to many"

    - by jan
    I have the following model: S belongs to T T has many S A,B,C,D,E (etc) have 1 T each, so the T should belong to each of A,B,C,D,E (etc) At first I set up my foreign keys so that in A, fk_a_t would be the foreign key on A.t to T(id), in B it'd be fk_b_t, etc. Everything looks fine in my UML (using MySQLWorkBench), but generating the yii models results in it thinking that T has many A,B,C,D (etc) which to me is the reverse. It sounds to me like either I need to have A_T, B_T, C_T (etc) tables, but this would be a pain as there are a lot of tables that have this relationship. I've also googled that the better way to do this would be some sort of behavior, such that A,B,C,D (etc) can behave as a T, but I'm not clear on exactly how to do this (I will continue to google more on this) What do you think is the better solution? UML: Here's the DDL (auto generated). Just pretend that there is more than 3 tables referencing T. -- ----------------------------------------------------- -- Table `mydb`.`T` -- ----------------------------------------------------- CREATE TABLE IF NOT EXISTS `mydb`.`T` ( `id` INT NOT NULL AUTO_INCREMENT , PRIMARY KEY (`id`) ) ENGINE = InnoDB; -- ----------------------------------------------------- -- Table `mydb`.`S` -- ----------------------------------------------------- CREATE TABLE IF NOT EXISTS `mydb`.`S` ( `id` INT NOT NULL AUTO_INCREMENT , `thing` VARCHAR(45) NULL , `t` INT NOT NULL , PRIMARY KEY (`id`) , INDEX `fk_S_T` (`id` ASC) , CONSTRAINT `fk_S_T` FOREIGN KEY (`id` ) REFERENCES `mydb`.`T` (`id` ) ON DELETE NO ACTION ON UPDATE NO ACTION) ENGINE = InnoDB; -- ----------------------------------------------------- -- Table `mydb`.`A` -- ----------------------------------------------------- CREATE TABLE IF NOT EXISTS `mydb`.`A` ( `id` INT NOT NULL AUTO_INCREMENT , `T` INT NOT NULL , `stuff` VARCHAR(45) NULL , `bar` VARCHAR(45) NULL , `foo` VARCHAR(45) NULL , PRIMARY KEY (`id`) , INDEX `fk_A_T` (`T` ASC) , CONSTRAINT `fk_A_T` FOREIGN KEY (`T` ) REFERENCES `mydb`.`T` (`id` ) ON DELETE NO ACTION ON UPDATE NO ACTION) ENGINE = InnoDB; -- ----------------------------------------------------- -- Table `mydb`.`B` -- ----------------------------------------------------- CREATE TABLE IF NOT EXISTS `mydb`.`B` ( `id` INT NOT NULL AUTO_INCREMENT , `T` INT NOT NULL , `stuff2` VARCHAR(45) NULL , `foobar` VARCHAR(45) NULL , `other` VARCHAR(45) NULL , PRIMARY KEY (`id`) , INDEX `fk_A_T` (`T` ASC) , CONSTRAINT `fk_A_T` FOREIGN KEY (`T` ) REFERENCES `mydb`.`T` (`id` ) ON DELETE NO ACTION ON UPDATE NO ACTION) ENGINE = InnoDB; -- ----------------------------------------------------- -- Table `mydb`.`C` -- ----------------------------------------------------- CREATE TABLE IF NOT EXISTS `mydb`.`C` ( `id` INT NOT NULL AUTO_INCREMENT , `T` INT NOT NULL , `stuff3` VARCHAR(45) NULL , `foobar2` VARCHAR(45) NULL , `other4` VARCHAR(45) NULL , PRIMARY KEY (`id`) , INDEX `fk_A_T` (`T` ASC) , CONSTRAINT `fk_A_T` FOREIGN KEY (`T` ) REFERENCES `mydb`.`T` (`id` ) ON DELETE NO ACTION ON UPDATE NO ACTION) ENGINE = InnoDB;

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  • Need help in displaying data insider marquee

    - by user59637
    Hi all, I want to display news inside the marquee markup in my banking application but its not happening.Please somebody help me what is the error in my code.Here is my code: <marquee bgcolor="silver" direction="left" id="marq1" runat="server" behavior="scroll" scrolldelay="80" style="height: 19px" width="565"> <% String se = Session["countnews"].ToString(); for (int i = 0; i < int.Parse("" +se); i++) { %> <strong><%Response.Write("&nbsp;&nbsp;" + Session["news"+i] + "&nbsp;&nbsp;"); %></strong> <% } %> </marquee> public class News { DataSet ds = new DataSet("Bank"); SqlConnection conn; String check; SqlDataAdapter sda; int i; public string News_Name; public int Count_News; public int newsticker() { conn = new SqlConnection(ConfigurationManager.ConnectionStrings["BankingTransaction"].ConnectionString.ToString()); check = "Select NewsTitle from News where NewsStatus = 'A'"; sda = new SqlDataAdapter(check, conn); sda.Fill(ds, "News"); if (ds.Tables[0].Rows.Count > 0) { for (i = 0; i < ds.Tables[0].Rows.Count; i++) { News_Name =i+ ds.Tables[0].Rows[i].ItemArray[0].ToString(); } Count_News = ds.Tables[0].Rows.Count; } else { News_Name =0+ "Welcome to WestSide Bank Online Web site!"; Count_News = 1; } return int.Parse(Count_News.ToString()); } protected void Page_Load(object sender, EventArgs e) { News obj = new News(); try { obj.newsticker(); Session["news"] = obj.News_Name.ToString(); Session["countnews"] = obj.Count_News.ToString(); } catch (SqlException ex) { Response.Write("Error in login" + ex.Message); Response.Redirect("Default.aspx"); } finally { obj = null; } }

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  • IQueryable and lazy loading

    - by Nelson
    I'm having a hard time determining the best way to handle this... With Entity Framework (and L2S), LINQ queries return IQueryable. I have read various opinions on whether the DAL/BLL should return IQueryable, IEnumerable or IList. Assuming we go with IList, then the query is run immediately and that control is not passed on to the next layer. This makes it easier to unit test, etc. You lose the ability to refine the query at higher levels, but you could simply create another method that allows you to refine the query and still return IList. And there are many more pros/cons. So far so good. Now comes Entity Framework and lazy loading. I am using POCO objects with proxies in .NET 4/VS 2010. In the presentation layer I do: foreach (Order order in bll.GetOrders()) { foreach (OrderLine orderLine in order.OrderLines) { // Do something } } In this case, GetOrders() returns IList so it executes immediately before returning to the PL. But in the next foreach, you have lazy loading which executes multiple SQL queries as it gets all the OrderLines. So basically, the PL is running SQL queries "on demand" in the wrong layer. Is there any sensible way to avoid this? I could turn lazy loading off, but then what's the point of having this "feature" that everyone was complaining EF1 didn't have? And I'll admit it is very useful in many scenarios. So I see several options: Somehow remove all associations in the entities and add methods to return them. This goes against the default EF behavior/code generation and makes it harder to do some composite (multiple entity) LINQ queries. It seems like a step backwards. I vote no. If we have lazy loading anyway which makes it hard to unit test, then go all the way and return IQueryable. You'll have more control farther up the layers. I still don't think this is a good option because IQueryable ties you to L2S, L2E, or your own full implementation of IQueryable. Lazy loading may run queries "on demand", but doesn't tie you to any specific interface. I vote no. Turn off lazy loading. You'll have to handle your associations manually. This could be with eager loading's .Include(). I vote yes in some specific cases. Keep IList and lazy loading. I vote yes in many cases, only due to the troubles with the others. Any other options or suggestions? I haven't found an option that really convinces me.

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  • ASP.NET MVC 2 AJAX dilemma: Lose Models concept or create unmanageable JavaScript

    - by Slightly Frustrated
    Hi, Ok, let's assume we are working with ASP.NET MVC 2 (latest and greatest preview) and we want to create AJAX user interface with jQuery. So what are our real options here? Option 1 - Pass Json from the Controller to the view, and then the view submits Json back to the controller. This means (in the order given): User opens some View (let's say - /Invoices/January) which has to visualize a list of data (e.g. <IEnumerable<X.Y.Z.Models.Invoice>>) Controller retrieves the Model from the repository (assuming we are using repository pattern). Controller creates a new instance of a class which we will serialize to Json. The reasaon we do this, is because the model may not be serializable (circular reference ftl) Controller populates the soon-to-be-serialized class with data Controller serializes the class to Json and passes it the view. User does some change and submits the 'form' The View submits back Json to the controller The Controller now must 'manually' validate the input, because the Json passed does not bind to a Model See, if our View is communicating to the controller via Json, we lose the Model validation, which IMHO is incredible disadvantage. In this case, forget about data annotations and stuff. Option 2 - Ok, the alternative of the first approach is to pass the Models to the Views, which is the default behavior in the template when you start a new project. We pass a strong typed model to the view The view renders the appropriate html and javascript, sticking to the model property names. This is important! The user submits the form. If we stick to the model names, when we .serialize() the form and submit it to the controller it will map to a model. There is no Json mapping. The submitted form directly binds to a strongly typed model, hence, we can use the model validation. E.g. we keep the business logic where it should be. Problem with this approach is, if we refactor some of the Models (change property names, types, etc), the javascript we wrote would become invalid. We will have to manually refactor the scripting and hope we don't miss something. There is no way you can test it either. Ok, the question is - how to write an AJAX front end, which keeps the business logic validation in the model (e.g. controller passes and receives a Model type), but in the same time doesn't screw up the javascript and html when we refactor the model?

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  • How to measure a canvas that has auto height and with

    - by Wymmeroo
    Hi Folks, I'm a beginner in silverlight so i hope i can get an answer that brings me some more light in the measure process of silverlight. I found an interessting flap out control from silverlight slide control and now I try to use it in my project. So that the slide out is working proper, I have to place the user control on a canvas. The user control then uses for itself the height of its content. I just wanna change that behavior so that the height is set to the available space from the parent canvas. You see the uxBorder where the height is set. How can I measure the actual height and set it to the border? I tried it with Height={Binding ElementName=notificationCanvas, Path=ActualHeight} but this dependency property has no callback, so the actualHeight is never set. What I want to achieve is a usercontrol like the tweetboard per example on Jesse Liberty's blog Sorry for my English writing, I hope you understand my question. <Canvas x:Name="notificationCanvas" Background="Red"> <SlideEffectEx:SimpleSlideControl GripWidth="20" GripTitle="Task" GripHeight="100"> <Border x:Name="uxBorder" BorderThickness="2" CornerRadius="5" BorderBrush="DarkGray" Background="DarkGray" Padding="5" Width="300" Height="700" > <StackPanel> <TextBlock Text="Tasks"></TextBlock> <Button x:Name="btn1" Margin="5" Content="{Binding ElementName=MainBorder, Path=Height}"></Button> <Button x:Name="btn2" Margin="5" Content="Second Button"></Button> <Button x:Name="btn3" Margin="5" Content="Third Button"></Button> <Button x:Name="btn1_Copy" Margin="5" Content="First Button"/> <Button x:Name="btn1_Copy1" Margin="5" Content="First Button"/> <Button x:Name="btn1_Copy2" Margin="5" Content="First Button"/> <Button x:Name="btn1_Copy3" Margin="5" Content="First Button"/> <Button x:Name="btn1_Copy4" Margin="5" Content="First Button"/> <Button x:Name="btn1_Copy5" Margin="5" Content="First Button"/> <Button x:Name="btn1_Copy6" Margin="5" Content="First Button"/> </StackPanel> </Border> </SlideEffectEx:SimpleSlideControl>

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  • ASP.Net 4.0 - Response required in SiteMap building?

    - by Nick Craver
    I'm running into an issue upgrading a project to .Net 4.0...and having trouble finding any reason for the issue (or at least, the change causing it). Given the freshness of 4.0, not a lot of blogs out there for issues yet, so I'm hoping someone here has an idea. Preface: this is a Web Forms application, coming from 3.5 SP1 to 4.0. In the Application_Start event we're iterating through the SiteMap and constructing routes based off data there (prettifying URLs mostly with some utility added), that part isn't failing though...or at least isn't not getting that far. It seems that calling the SiteMap.RootNode (inside application_start) causes 4.0 to eat it, since the XmlSiteMapProvider.GetNodeFromXmlNode method has been changed, looking in reflector you can see it's hitting HttpResponse.ApplyAppPathModifier here: str2 = HttpContext.Current.Response.ApplyAppPathModifier(str2); HttpResponse wasn't used at all in this method in the 2.0 CLR, so what we had worked fine, in 4.0 though, that method is called as a result of this stack: [HttpException (0x80004005): Response is not available in this context.] System.Web.XmlSiteMapProvider.GetNodeFromXmlNode(XmlNode xmlNode, Queue queue) System.Web.XmlSiteMapProvider.ConvertFromXmlNode(Queue queue) System.Web.XmlSiteMapProvider.BuildSiteMap() System.Web.XmlSiteMapProvider.get_RootNode() System.Web.SiteMap.get_RootNode() Since Response isn't available here in 4.0, we get an error. To reproduce this, you can narrow the test case down to this in global: protected void Application_Start(object sender, EventArgs e) { var s = SiteMap.RootNode; //Kaboom! //or just var r = Context.Response; //or var r = HttpContext.Current.Response; //all result in the same "not available" error } Question: Am I missing something obvious here? Or, is there another event added in 4.0 that's recommended for anything related to SiteMap on startup? For anyone curious/willing to help, I've created a very minimal project (a default VS 2010 ASP.Net 4.0 site, all the bells & whistles removed and only a blank sitemap and the Application_Start code added). It's a small 10kb zip available here: http://www.ncraver.com/Test/SiteMapTest.zip Update: Not a great solution, but the current work-around is to do the work in Application_BeginRequest, like this: private static bool routesRegistered = false; protected void Application_BeginRequest(object sender, EventArgs e) { if (!routesRegistered) { Application.Lock(); if (!routesRegistered) RouteManager.RegisterRoutes(RouteTable.Routes); routesRegistered = true; Application.UnLock(); } } I don't like this particularly, feels like an abuse of the event to bypass the issue. Does anyone have at least a better work-around, since the .Net 4 behavior with SiteMap is not likely to change?

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  • ArithmeticException thrown during BigDecimal.divide

    - by polygenelubricants
    I thought java.math.BigDecimal is supposed to be The Answer™ to the need of performing infinite precision arithmetic with decimal numbers. Consider the following snippet: import java.math.BigDecimal; //... final BigDecimal one = BigDecimal.ONE; final BigDecimal three = BigDecimal.valueOf(3); final BigDecimal third = one.divide(three); assert third.multiply(three).equals(one); // this should pass, right? I expect the assert to pass, but in fact the execution doesn't even get there: one.divide(three) causes ArithmeticException to be thrown! Exception in thread "main" java.lang.ArithmeticException: Non-terminating decimal expansion; no exact representable decimal result. at java.math.BigDecimal.divide It turns out that this behavior is explicitly documented in the API: In the case of divide, the exact quotient could have an infinitely long decimal expansion; for example, 1 divided by 3. If the quotient has a non-terminating decimal expansion and the operation is specified to return an exact result, an ArithmeticException is thrown. Otherwise, the exact result of the division is returned, as done for other operations. Browsing around the API further, one finds that in fact there are various overloads of divide that performs inexact division, i.e.: final BigDecimal third = one.divide(three, 33, RoundingMode.DOWN); System.out.println(three.multiply(third)); // prints "0.999999999999999999999999999999999" Of course, the obvious question now is "What's the point???". I thought BigDecimal is the solution when we need exact arithmetic, e.g. for financial calculations. If we can't even divide exactly, then how useful can this be? Does it actually serve a general purpose, or is it only useful in a very niche application where you fortunately just don't need to divide at all? If this is not the right answer, what CAN we use for exact division in financial calculation? (I mean, I don't have a finance major, but they still use division, right???).

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  • Constructor versus setter injection

    - by Chris
    Hi, I'm currently designing an API where I wish to allow configuration via a variety of methods. One method is via an XML configuration schema and another method is through an API that I wish to play nicely with Spring. My XML schema parsing code was previously hidden and therefore the only concern was for it to work but now I wish to build a public API and I'm quite concerned about best-practice. It seems that many favor javabean type PoJo's with default zero parameter constructors and then setter injection. The problem I am trying to tackle is that some setter methods implementations are dependent on other setter methods being called before them in sequence. I could write anal setters that will tolerate themselves being called in many orders but that will not solve the problem of a user forgetting to set the appropriate setter and therefore the bean being in an incomplete state. The only solution I can think of is to forget about the objects being 'beans' and enforce the required parameters via constructor injection. An example of this is in the default setting of the id of a component based on the id of the parent components. My Interface public interface IMyIdentityInterface { public String getId(); /* A null value should create a unique meaningful default */ public void setId(String id); public IMyIdentityInterface getParent(); public void setParent(IMyIdentityInterface parent); } Base Implementation of interface: public abstract class MyIdentityBaseClass implements IMyIdentityInterface { private String _id; private IMyIdentityInterface _parent; public MyIdentityBaseClass () {} @Override public String getId() { return _id; } /** * If the id is null, then use the id of the parent component * appended with a lower-cased simple name of the current impl * class along with a counter suffix to enforce uniqueness */ @Override public void setId(String id) { if (id == null) { IMyIdentityInterface parent = getParent(); if (parent == null) { // this may be the top level component or it may be that // the user called setId() before setParent(..) } else { _id = Helpers.makeIdFromParent(parent,getClass()); } } else { _id = id; } } @Override public IMyIdentityInterface getParent() { return _parent; } @Override public void setParent(IMyIdentityInterface parent) { _parent = parent; } } Every component in the framework will have a parent except for the top level component. Using the setter type of injection, then the setters will have different behavior based on the order of the calling of the setters. In this case, would you agree, that a constructor taking a reference to the parent is better and dropping the parent setter method from the interface entirely? Is it considered bad practice if I wish to be able to configure these components using an IoC container? Chris

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  • How can I have a Makefile automatically rebuild source files that include a modified header file? (I

    - by Nicholas Flynt
    I have the following makefile that I use to build a program (a kernel, actually) that I'm working on. Its from scratch and I'm learning about the process, so its not perfect, but I think its powerful enough at this point for my level of experience writing makefiles. AS = nasm CC = gcc LD = ld TARGET = core BUILD = build SOURCES = source INCLUDE = include ASM = assembly VPATH = $(SOURCES) CFLAGS = -Wall -O -fstrength-reduce -fomit-frame-pointer -finline-functions \ -nostdinc -fno-builtin -I $(INCLUDE) ASFLAGS = -f elf #CFILES = core.c consoleio.c system.c CFILES = $(foreach dir,$(SOURCES),$(notdir $(wildcard $(dir)/*.c))) SFILES = assembly/start.asm SOBJS = $(SFILES:.asm=.o) COBJS = $(CFILES:.c=.o) OBJS = $(SOBJS) $(COBJS) build : $(TARGET).img $(TARGET).img : $(TARGET).elf c:/python26/python.exe concat.py stage1 stage2 pad.bin core.elf floppy.img $(TARGET).elf : $(OBJS) $(LD) -T link.ld -o $@ $^ $(SOBJS) : $(SFILES) $(AS) $(ASFLAGS) $< -o $@ %.o: %.c @echo Compiling $<... $(CC) $(CFLAGS) -c -o $@ $< #Clean Script - Should clear out all .o files everywhere and all that. clean: -del *.img -del *.o -del assembly\*.o -del core.elf My main issue with this makefile is that when I modify a header file that one or more C files include, the C files aren't rebuilt. I can fix this quite easily by having all of my header files be dependencies for all of my C files, but that would effectively cause a complete rebuild of the project any time I changed/added a header file, which would not be very graceful. What I want is for only the C files that include the header file I change to be rebuilt, and for the entire project to be linked again. I can do the linking by causing all header files to be dependencies of the target, but I cannot figure out how to make the C files be invalidated when their included header files are newer. I've heard that GCC has some commands to make this possible (so the makefile can somehow figure out which files need to be rebuilt) but I can't for the life of me find an actual implementation example to look at. Can someone post a solution that will enable this behavior in a makefile? EDIT: I should clarify, I'm familiar with the concept of putting the individual targets in and having each target.o require the header files. That requires me to be editing the makefile every time I include a header file somewhere, which is a bit of a pain. I'm looking for a solution that can derive the header file dependencies on its own, which I'm fairly certain I've seen in other projects.

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