Search Results

Search found 17047 results on 682 pages for 'architecture design patt'.

Page 655/682 | < Previous Page | 651 652 653 654 655 656 657 658 659 660 661 662  | Next Page >

  • Make html footer occupy the rest of the body

    - by w0rldart
    So I am trying to code the footer of my web app of it occupies the rest of the body's height. Picture: http://img1.uploadscreenshot.com/images/orig/3/8906151296-orig.png Notice the light area beneath the dark area, the dark area should occupy all of it. Some of my html code: <body> .... <footer> <hr> <ul id="footerContainer"> <li class="right"> <ul> <li> <a href="" class="family-filter">Filtro Fami....</a> </li> </ul> </li> </ul> </footer> <script>...</script> </body></html> CSS: .... #footerContainer {width: 90%; min-width: 525px; margin: 0 auto; position: relative;} .... footer hr{ border: 0; height: 30px; background: url('../imgs/footer-top.png') repeat-x scroll; } footer { background: url('../imgs/footer-bg.png') repeat scroll bottom; height: 100%; display: block; margin: 0 auto; padding: 0; overflow: auto; } #footerContainer {margin: 0 auto; position: relative;} #footerContainer li { display: inline;} #footerContainer li .right {float: right;} #footerContainer li a {} Any suggestions? Update1: This is what happens: http://img1.uploadscreenshot.com/images/orig/3/8906391235-orig.png when I set html,body { width: 100%; height: 100%; margin: 0; padding: 0; } Update2: http://awesomescreenshot.com/0382hf1ff Zoom out and in at this page: line25.com/wp-content/uploads/2010/blog-design-coded/demo/… and check the footer area, that's how I need it work on my layout.

    Read the article

  • dojo layout tutorial dor version 1.7 doesn't work for 1.7.2

    - by Sheena
    This is sortof a continuation to dojo1.7 layout acting screwy. So I made some working widgets and tested them out, i then tried altering my work using the tutorial at http://dojotoolkit.org/documentation/tutorials/1.7/dijit_layout/ to make the layout nice. After failing at that in many interesting ways (thus my last question) I started on a new path. My plan is now to implement the layout tutorial example and then stick in my widgets. For some reason even following the tutorial wont work... everything loads then disappears and I'm left with a blank browser window. Any ideas? It just struck me that it could be browser compatibility issues, I'm working on Firefox 13.0.1. As far as I know Dojo is supposed to be compatible with this... anyway, have some code: HTML: <body class="claro"> <div id="appLayout" class="demoLayout" data-dojo-type="dijit.layout.BorderContainer" data-dojo-props="design: 'headline'"> <div class="centerPanel" data-dojo-type="dijit.layout.ContentPane" data-dojo-props="region: 'center'"> <div> <h4>Group 1 Content</h4> <p>stuff</p> </div> <div> <h4>Group 2 Content</h4> </div> <div> <h4>Group 3 Content</h4> </div> </div> <div class="edgePanel" data-dojo-type="dijit.layout.ContentPane" data-dojo-props="region: 'top'"> Header content (top) </div> <div id="leftCol" class="edgePanel" data-dojo-type="dijit.layout.ContentPane" data-dojo-props="region: 'left', splitter: true"> Sidebar content (left) </div> </div> </body> Dojo Configuration: var dojoConfig = { baseUrl: "${request.static_url('mega:static/js')}", //this is in a mako template tlmSiblingOfDojo: false, packages: [ { name: "dojo", location: "libs/dojo" }, { name: "dijit", location: "libs/dijit" }, { name: "dojox", location: "libs/dojox" }, ], parseOnLoad: true, has: { "dojo-firebug": true, "dojo-debug-messages": true }, async: true }; other js stuff: require(["dijit/layout/BorderContainer", "dijit/layout/TabContainer", "dijit/layout/ContentPane", "dojo/parser"]); css: html, body { height: 100%; margin: 0; overflow: hidden; padding: 0; } #appLayout { height: 100%; } #leftCol { width: 14em; }

    Read the article

  • Is there a recommended approach to handle saving data in response to within-site navigation without

    - by Carvell Fenton
    Hello all, Preamble to scope my question: I have a web app (or site, this is an internal LAN site) that uses jQuery and AJAX extensively to dynamically load the content section of the UI in the browser. A user navigates the app using a navigation menu. Clicking an item in the navigation menu makes an AJAX call to php, and php then returns the content that is used to populate the central content section. One of the pages served back by php has a table form, set up like a spreadsheet, that the user enters values into. This table is always kept in sync with data in the database. So, when the table is created, is it populated with the relevant database data. Then when the user makes a change in a "cell", that change immediately is written back to the database so the table and database are always in sync. This approach was take to reassure users that the data they entered has been saved (long story...), and to alleviate them from having to click a save button of some kind. So, this always in sync idea is great, except that a user can enter a value in a cell, not take focus out of the cell, and then take any number of actions that would cause that last value to be lost: e.g. navigate to another section of the site via the navigation menu, log out of the app, close the browser, etc. End of preamble, on to the issue: I initially thought that wasn't a problem, because I would just track what data was "dirty" or not saved, and then in the onunload event I would do a final write to the database. Herein lies the rub: because of my clever (or not so clever, not sure) use of AJAX and dynamically loading the content section, the user never actually leaves the original url, or page, when the above actions are taken, with the exception of closing the browser. Therefore, the onunload event does not fire, and I am back to losing the last data again. My question, is there a recommended way to handle figuring out if a person is navigating away from a "section" of your app when content is dynamically loaded this way? I can come up with a solution I think, that involves globals and tracking the currently viewed page, but I thought I would check if there might be a more elegant solution out there, or a change I could make in my design, that would make this work. Thanks in advance as always!

    Read the article

  • Why does my entire page reload in Chrome and Firefox when using asynchronous UpdatePanel postbacks?

    - by Alex
    Being a bit perplexed about this issue by now, I hope some of you gurus can shed some light on my problem... I've developed a AJAX-enhanced website, which has been running fine in IE, Chrome and Firefox for a year or so. I use a Timer-control to check for incoming messages every 30 seconds, and this updates an UpdatePanel showing potential new messages. Now several one of my Firefox users complain about the page refreshing every 30 seconds! I my self cannot reproduce this behaviour, but given the "30 seconds"-description, I cursed my Timer-solution as the culprit. But now, I'm experiencing this error myself, not in Firefox though, but in Google Chrome! (And only on one of my two computers!) Every 30 seconds the page reloads! But I found that it's not only related to the Timer, because all other asynchronous postbacks to the server within UpdatePanels reloads the entire page as well. This error has never been experienced in Internet Explorer (to my knowledge). As I said, this it not only related to the Timer postback, but if it's of interest to anybody the code is like this: <asp:Timer runat="server" ID="MailCheckTimer" Interval="30000" OnTick="MailChecker_Tick"></asp:Timer> <asp:UpdatePanel runat="server" ID="MailCheckerUpdatePanel" UpdateMode="Conditional"> <ContentTemplate> <div class="newmail_box" runat="server" id="newmail_box"> <!-- Content stripped for this example --> </div> </ContentTemplate> <Triggers> <asp:AsyncPostBackTrigger ControlID="MailCheckTimer" /> </Triggers> </asp:UpdatePanel> In other places of the website I call the client side __doPostBack function directly from JavaScript in relation to an UpdatePanel. Normal behaviour for this call is to updated the referenced UpdatePanel with some content, but now in Chrome this refreshes the entire page! (but again not consistently, and never in IE) Even the most fundamental UpdatePanel operations like refreshing the content after a button (inside the panel) is clicked, forces the page to reload completely: <asp:Button ID="btnSearch" runat="server" Text="Search" OnClick="btnSearch_Click"></asp:Button> And just to torment me further, I only experience this on my public website, and not in my local development environment, making it a tedious affair for me to find the actual cause! :( Any ideas on why this happens? Why so inconsistently? Has it to do with my UpdatePanel-design? Or does some security setting in Firefox/Chrome that prevent some asynchronous UpdatePanel callbacks? Any help or idea is highly appreciated!

    Read the article

  • Myself throwing NullReferenceException... needs help

    - by Amit Ranjan
    I know it might be a weird question and its Title too, but i need your help. I am a .net dev , working on platform for the last 1.5 years. I am bit confused on the term usually we say " A Good Programmer ". I dont know ,what are the qualities of a good programmer ? Is the guy who writes a bug free code? or Can develop applications solely? or blah blah blah...lots of points. I dont know... But as far i am concerned , I know I am not a good programmer, still in learning phase an needs a lot to learn in coming days. So you guys are requested to please help me with this two problems of mine My first problem is regarding the proper Error Handling, which is a most debatable aspect of programming. We all know we use ` try { } catch { } finally { } ` in our code to manage exception. But even if I use try { } catch(exception ex) { throw ex } finally { } , different guys have different views. I still dont know the good way to handle errors. I can write code, use try-catch but still i feel I lacks something. When I saw the codes generated by .net fx tools even they uses throw ex or `throw new Exception("this is my exception")`.. I am just wondering what will be the best way to achieve the above. All means the same thing but why we avoid something. If it has some demerits then it must be made obselete.Anyways I still dont have one [how to handle errors efficiently?]. I generally follow the try-catch(execoption ex){throw ex}, and usually got stucked in debates with leads why you follow this why not that... 2.Converting your entire code blocks in modules using Design patterns of some OOPs concepts. How do you guys decide what architeture or pattern will be the best for my upcoming application based on its working, flow etc. I need to know what you guys can see that I can't. Since I know , I dont have that much experience but I can say, with my experience that experience doesnot comes either from degree/certificates or success you made instead it cames from failures you faced or got stucking situations. Pleas help me out.

    Read the article

  • Windows Question: RunOnce/Second Boot Issues [closed]

    - by Greg
    Moved to Super User: Windows Question: RunOnce/Second Boot Issues I am attempting to create a Windows XP SP3 image that will run my application on Second Boot. Here is the intended workflow. 1) Run Image Prep Utility (I wrote) on windows to add my runonce entries and clean a few things up. 2) Reboot to ghost, make image file. 3) Package into my ISO and distribute. 4) System will be imaged by user. 5) On first boot, I have about 5 things that run, one of which includes a driver updater (I wrote) for my own specific devices. 6) One of the entries inside of HKCU/../runonce is a reg file, which adds another key to HKLM/../runonce. This is how second boot is acquired. 7) As a result of the driver updater, user is prompted to reboot. 8) My application is then launched from HKLM/../runonce on second boot. This workflow works perfectly, except for a select few legacy systems that contain devices that cause the add hardware wizard to pop up. When the add hardware wizard pops up is when I begin to see problems. It's important to note, that if I manually inspect the registry after the add hardware wizard pops up, it appears as I would expect, with all the first boot scripts having run, and it's sitting in a state I would correctly expect it to be in for a second boot scenario. The problem comes when I click next on the add hardware wizard, it seems to re-run the single entry I've added, and re-executes the runonce scripts. (only one script now as it's already executed and cleared out the initial entries). This causes my application to open as if it were a second boot, only when next is clicked on the add hardware wizard. If I click cancel, and reboot, then it also works as expected. I don't care as much about other solutions, because I could design a system that doesn't fully rely on Microsoft's registry. I simply can't find any information as to WHY this is happening. I believe this is some type of Microsoft issue that's presenting itself as a result of an overstretched image that's expected to support too many legacy platforms, but any help that can be provided would be appreciated. Thanks,

    Read the article

  • PHP GD Allowed memory size exhausted

    - by gurun8
    I'm trying to process a directory of JPEG images (roughly 600+, ranging from 50k to 500k) using PHP: GD to resize and save the images but I've hit a bit of a snag quite early in the process. After correctly processing just 3 images (30K, 18K and 231K) I get a Allowed memory size of 16777216 bytes exhausted PHP Fatal error. I'm cycling through the images and calling the code below: list($w, $h) = getimagesize($src); if ($w > $it->width) { $newwidth = $it->width; $newheight = round(($newwidth * $h) / $w); } elseif ($w > $it->height) { $newheight = $it->height; $newwidth = round(($newheight * $w) / $h); } else { $newwidth = $w; $newheight = $h; } // create resize image $img = imagecreatetruecolor($newwidth, $newheight); $org = imagecreatefromjpeg($src); // Resize imagecopyresized($img, $org, 0, 0, 0, 0, $newwidth, $newheight, $w, $h); imagedestroy($org); imagejpeg($img, $dest); // Free up memory imagedestroy($img); I've tried to free up memory with the imagedestroy function but it doesn't seem to have any affect. The script just keeps consistently choking at the imagecreatefromjpeg line of code. I checked the php.ini and the memory_limit = 16M setting seems like it's holding correctly. But I can't figure out why the memory is filling up. Shouldn't it be releasing the memory back to the garbage collector? I don't really want to increase the memory_limit setting. This seems like a bad workaround that could potentially lead to more issues in the future. FYI: I'm running my script from a command prompt. It shouldn't affect the functionality but might influence your response so I thought I should mention it. Can anyone see if I'm just missing something simple or if there's a design flaw here? You'd think that this would be a pretty straightforward task. Surely this has to be possible, right?

    Read the article

  • Unresolved External Symbol linker error (C++)

    - by Niranjan
    Hi, I am trying to develop abstract design pattern code for one of my project as below.. But, I am not able to compile the code ..giving some compile errors(like "unresolved external symbol "public: virtual void __thiscall Xsecs::draw_lines(double,double)" (?draw_lines@Xsecs@@UAEXNN@Z)" ).. Can any one please help me out in this... #include "stdafx.h" #include <iostream> #include <vector> #include "Xsecs.h" using namespace std; //Product class class Xsecs { public: virtual void draw_lines(double pt1, double pt2); virtual void draw_curves(double pt1, double rad); }; class polyline: public Xsecs { public: virtual void draw_lines(double pt1,double pt2) { cout<<"draw_line in polygon"<<endl; } virtual void draw_curves(double pt1, double rad) { cout<<"Draw_curve in circle"<<endl; } /*void create_polygons() { cout<<"create_polygon_thru_draw_lines"<<endl; }*/ }; class circle: public Xsecs { public: virtual void draw_lines(double pt1,double pt2) { cout<<"draw_line in polygon"<<endl; } virtual void draw_curves(double pt1, double rad) { cout<<"Draw_curve in circle"<<endl; } /*void create_circles() { cout<<"Create circle"<<endl; }*/ }; //Factory class class Factory { public: virtual polyline* create_polyline()=0; virtual circle* create_circle()=0; }; class Factory1: public Factory { public: polyline* create_polyline() { return new polyline(); } circle* create_circle() { return new circle(); } }; class Factory2: public Factory { public: circle* create_circle() { return new circle(); } polyline* create_polyline() { return new polyline(); } }; int _tmain(int argc, _TCHAR* argv[]) { Factory1 f1; Factory * fp=&f1; return 0; }

    Read the article

  • How to deal with class composition when components cannot be accessed from the outside?

    - by Chathuranga
    For example if I say I have three classes A, B, and C where B and C have a composition relation ship with A. That means the life of B and C is handled by A, and also B and C cannot access directly from the outside. For some reason my DataService class needs to return objects of B and C as It cant return a object of A as B and C cannot be initialized at the same time. (to be able to initializeC you have to initializeB first). So that I'm returning DataTables from DataService and then inside the class A those data tables are converted to B / C objects. If B and C objects cannot be initialized at the same time is it valid to say that B and C have a composition relationship with A? If its composition is it must to generate A with B and C inside? What is the proper way to handle this sort of a problem? EDIT: Following code explains the way I'm doing it now with DataTables. Example: class A { private List<B> B; private List <C> C; public A() { B= new List<B>(); C= new List<C>(); } public List<B> GetB( DataTable dt) { // Create a B list from dt return B; } } class Presenter { private void Show B() { _View.DataGrid = A.GetB(DataService.GetAListOfB()); } } The actual scenario is I have a class called WageInfo and classes Earning and Deduction having a composition relationship in the design. But for you to generate Deductions first you should Generate earnings and should be saved in a table. Then only you can generate deductions for the earnings to calculate balance wages. Also note that these contained classes have a one to many relationship with the containing class WageInfo. So actually WageInfo has a List<Earnings> and List<Deduction> My initial question was, is it ok if my DataService class returns Deductions / Earnings objects (actually lists) not a WageInfo? Still not clear?

    Read the article

  • New cast exception with VS2010/.Net 4

    - by Trevor
    [ Updated 25 May 2010 ] I've recently upgraded from VS2008 to VS2010, and at the same time upgraded to .Net 4. I've recompiled an existing solution of mine and I'm encountering a Cast exception I did not have before. The structure of the code is simple (although the actual implementation somewhat more complicated). Basically I have: public class SomeClass : ISomeClass { // Stuff } public static class ClassFactory { public static IInterface GetClassInstance<IInterface>(Type classType) { return (IInterface)Activator.CreateInstance(classType); // This throws a cast exception } } // Call the factory with: ISomeClass anInstance = ClassFactory.GetClassInstance<ISomeClass>(typeof(SomeClass)); Ignore the 'sensibleness' of the above - its provides just a representation of the issue rather than the specifics of what I'm doing (e.g. constructor parameters have been removed). The marked line throws the exception: Unable to cast object of type 'Namespace.SomeClass' to type 'Namespace.ISomeClass'. I suspect it may have something to do with the additional DotNet security (and in particular, explicit loading of assemblies, as this is something my app does). The reason I suspect this is that I have had to add to the config file the setting: <runtime> <loadFromRemoteSources enabled="true" /> </runtime> .. but I'm unsure if this is related. Update I see (from comments) that my basic code does not reproduce the issue by itself. Not surprising I suppose. It's going to be tricky to identify which part of a largish 3-tier CQS system is relevant to this problem. One issue might be that there are multiple assemblies involved. My static class is actually a factory provider, and the 'SomeClass' is a class factory (relevant in that the factories are 'registered' within the app via explicit assembly/type loading - see below) . Upfront I use reflection to 'register' all factories (i.e. classes that implement a particular interface) and that I do this when the app starts by identifying the relevant assemblies, loading them and adding them to a cache using (in essence): Loop over (file in files) { Assembly assembly = Assembly.LoadFile(file); baseAssemblyList.Add(assembly); } Then I cache the available types in these assemblies with: foreach (Assembly assembly in _loadedAssemblyList) { Type[] assemblyTypes = assembly.GetTypes(); _loadedTypesCache.AddRange(assemblyTypes); } And then I use this cache to do a variety of reflection operations, including 'registering' of factories, which involves looping through all loaded (cached) types and finding those that implement the (base) Factory interface. I've experienced what may be a similar problem in the past (.Net 3.5, so not exactly the same) with an architecture that involved dynamically creating classes on the server and streaming the compiled binary of those classes to the client app. The problem came when trying to deserialize an instance of the dynamic class on the client from a remote call: the exception said the class type was not know, even though the source and destination types were exactly the same name (including namespace). Basically the cross boundry versions of the class were not recognised as being the same. I solved that by intercepting the deserialization process and explicitly defining the deseriazation class type in the context of the local assemblies. This experience is what makes me think the types are considered mismatched because (somehow) the interface of the actual SomeClass object, and the interface of passed into the Generic method are not considered the same type. So (possibly) my question for those more knowledgable about C#/DotNet is: How does the class loading work that somehow my app thinks there are two versions/types of the interface type and how can I fit that? [ whew ... anyone who got here is quite patient .. thanks ]

    Read the article

  • Problem with continue in While Loop within Try/Catch in C# (2.0)

    - by csharpnoob
    Hi, when i try to use in my ASPX Webpage in the Code Behind this try{ while() { ... db.Open(); readDataMoney = new OleDbCommand("SELECT * FROM Customer WHERE card = '" + customer.card + "';", db).ExecuteReader(); while (readDataMoney.Read()) { try { if (!readDataMoney.IsDBNull(readDataMoney.GetOrdinal("Credit"))) { customer.credit = Convert.ToDouble(readDataMoney[readDataMoney.GetOrdinal("Credit")]); } if (!readDataMoney.IsDBNull(readDataMoney.GetOrdinal("Bonus"))) { customer.bonus = Convert.ToDouble(readDataMoney[readDataMoney.GetOrdinal("Bonus")]); } } catch (Exception ex) { Connector.writeLog("Money: " + ex.StackTrace + "" + ex.Message + "" + ex.Source); customer.credit = 0.0; customer.credit = 0.0; continue; } finally { } } readDataMoney.Close(); vsiDB.Close(); ... } }catch { continue; } The whole page hangs if there is a problem when the read from db isn't working. I tried to check for !isNull, but same problem. I have a lots of differend MDB Files to process, which are readonly (can't repair/compact) and some or others not. Same Design/Layout of Tables. With good old ASP Classic 3.0 all of them are processing with the "On Resume Next". I know I know. But that's how it is. Can't change the source. So the basic question: So is there any way to tell .NET to continue the loop whatever happens within the try loop if there is any exception? After a lots of wating time i get this exceptions: at System.Data.Common.UnsafeNativeMethods.IDBInitializeInitialize.Invoke(IntPtr pThis) at System.Data.OleDb.DataSourceWrapper.InitializeAndCreateSession(OleDbConnectionString constr, SessionWrapper& sessionWrapper) at System.Data.OleDb.OleDbConnectionInternal..ctor(OleDbConnectionString constr, OleDbConnection connection) at System.Data.OleDb.OleDbConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.CreateNonPooledConnection(DbConnection owningConnection, DbConnectionPoolGroup poolGroup) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.OleDb.OleDbConnection.Open() at GetCustomer(String card)Thread was being aborted.System.Data and System.Runtime.InteropServices.Marshal.ReadInt16(IntPtr ptr, Int32 ofs) System.Data.ProviderBase.DbBuffer.ReadInt16(Int32 offset) System.Data.OleDb.ColumnBinding.Value_I2() System.Data.OleDb.ColumnBinding.Value() System.Data.OleDb.OleDbDataReader.GetValue(Int32 ordinal) System.Data.OleDb.OleDbDataReader.get_Item(Int32 index) Thread was terminated.mscorlib Thanks for any help.

    Read the article

  • Dynamically find other hosts in a LAN in Java

    - by Federico Cristina
    A while ago I developed a little LAN chat app. in Java which allows chatting with other hosts, send images, etc. Although it was created just for fun, now it's being used where I work. Currently, there is no "chat server" on the app. where each client registers, updates it's status, etc. (I liked the idea of symmetric design and not depending on a server running on some other machine). Instead, each host is a client/server which has a hosts.properties file with the hostname of the other hosts, and - for instance - broadcasts to each one of them when sending a massive message/image/whatever. In the beginning there were just a couple of hosts, so this hosts.properties file wasn't an issue. But as the amount of users increased, the need of updating that file was a bit daunting. So now I've decided to get rid of it, and each time the app. starts, dynammically find the other active hosts. However, I cannot find the correct way of implement this. I've tried starting different threads, each one of them searching for other hosts in a known range of IP addresses. Something like this (simplified for the sake of readability): /** HostsLocator */ public static void searchForHosts(boolean waitToEnd) { for (int i=0; i < MAX_IP; i+= MAX_IP / threads) { HostsLocator detector = new HostsLocator(i, i+(MAX_IP / threads - 1)); // range: from - to new Thread(detector).start(); } } public void run() { for (int i=from; i<=to; i++) findHosts( maskAddress + Integer.toString(i) ); } public static boolean findHosts(String IP) { InetAddress address = InetAddress.getByName(IP); if ( address.isReachable(CONNECTION_TIME_OUT) ) // host found! } However: With a single thread and a low value in CONNECTION_TIME_OUT (500ms) I get wrong Host Not Found status for for hosts actually active. With a high value in CONNECTION_TIME_OUT (5000ms) and only one single thread takes forever to end With several threads I've also found problems similar like the first one, due to collisions. So... I guess there's a better way of solving this problem but I couldn't find it. Any advice? Thanks!

    Read the article

  • Delphi Unit local variables - how to make each instance unique?

    - by Justin
    Ok, this, I'm sure is something simple that is easy to do. The problem : I've inherited scary spaghetti code and am slowly trying to better it when new features need adding - generally when a refactor makes adding the new feature neater. I've got a bunch of code I'm packing into a single unit which, in different places in the application, controls the same physical thing in the outside world. The control appears in several places in the application and operates slightly differently in each instance. What I've done is to create a unit with all of the features I need which I can simply drop, as a frame, into each form that requires it. Each form then uses the unit's interface methods to customise the behaviour for each instance. The problem within the problem : In the unit in question (the frame) I have a variable declared in the IMPLEMENTATION section - local to the unit. I also have a procedure, declared in the TYPE section which takes an argument and assigns that argument to the local variable in question - each form passes a unique variable to each instance of the frame/unit. What I want it to do is for each instance of the frame to keep its own version of that variable, different from the others, and use that to define how it operates. What seems to be happening, however, is that all instances are using the same value, even if I explicitly pass each instance a different variable. ie: Unit FlexibleUnit; interface uses //the uses stuff type TFlexibleUnit=class(TFrame) //declarations including procedure makeThisInstanceX(passMeTheVar:integer); private // public // end; implementation uses //the uses var myLocalVar; procedure makeThisInstanceX(passMeTheVar:integer); begin myLocalVar:=passMeTheVar; end; //other procedures using myLocalVar //etc to the end; Now somewhere in another Form I've dropped this Frame onto the Design pane, sometimes two of these frames on one Form, and have it declared in the proper places, etc. Each is unique in that : ThisFlexibleUnit : TFlexibleUnit; ThatFlexibleUnit : TFlexibleUnit; and when I do a: ThisFlexibleUnit.makeThisInstanceX(var1); //want to behave in way "var1" ThatFlexibleUnit.makeThisInstanceX(var2); //want to behave in way "var2" it seems that they both share the same variable "myLocalVar". Am I doing this wrong, in principle? If this is the correct method then it's a matter of debugging what I have (which is too huge to post) but if this is not correct in principle then is there a way to do what I am suggesting? Thanks in advance, Stack Overflow - you guys (and gals!) are legendary.

    Read the article

  • Perl - Calling subclass constructor from superclass (OO)

    - by Emmel
    This may turn out to be an embarrassingly stupid question, but better than potentially creating embarrassingly stupid code. :-) This is an OO design question, really. Let's say I have an object class 'Foos' that represents a set of dynamic configuration elements, which are obtained by querying a command on disk, 'mycrazyfoos -getconfig'. Let's say that there are two categories of behavior that I want 'Foos' objects to have: Existing ones: one is, query ones that exist in the command output I just mentioned (/usr/bin/mycrazyfoos -getconfig`. Make modifications to existing ones via shelling out commands. Create new ones that don't exist; new 'crazyfoos', using a complex set of /usr/bin/mycrazyfoos commands and parameters. Here I'm not really just querying, but actually running a bunch of system() commands. Affecting changes. Here's my class structure: Foos.pm package Foos, which has a new($hashref-{name = 'myfooname',) constructor that takes a 'crazyfoo NAME' and then queries the existence of that NAME to see if it already exists (by shelling out and running the mycrazyfoos command above). If that crazyfoo already exists, return a Foos::Existing object. Any changes to this object requires shelling out, running commands and getting confirmation that everything ran okay. If this is the way to go, then the new() constructor needs to have a test to see which subclass constructor to use (if that even makes sense in this context). Here are the subclasses: Foos/Existing.pm As mentioned above, this is for when a Foos object already exists. Foos/Pending.pm This is an object that will be created if, in the above, the 'crazyfoo NAME' doesn't actually exist. In this case, the new() constructor above will be checked for additional parameters, and it will go ahead and, when called using -create() shell out using system() and create a new object... possibly returning an 'Existing' one... OR As I type this out, I am realizing it is perhaps it's better to have a single: (an alternative arrangement) Foos class, that has a -new() that takes just a name -create() that takes additional creation parameters -delete(), -change() and other params that affect ones that exist; that will have to just be checked dynamically. So here we are, two main directions to go with this. I'm curious which would be the more intelligent way to go.

    Read the article

  • How to handle environment-specific application configuration organization-wide?

    - by Stuart Lange
    Problem Your organization has many separate applications, some of which interact with each other (to form "systems"). You need to deploy these applications to separate environments to facilitate staged testing (for example, DEV, QA, UAT, PROD). A given application needs to be configured slightly differently in each environment (each environment has a separate database, for example). You want this re-configuration to be handled by some sort of automated mechanism so that your release managers don't have to manually configure each application every time it is deployed to a different environment. Desired Features I would like to design an organization-wide configuration solution with the following properties (ideally): Supports "one click" deployments (only the environment needs to be specified, and no manual re-configuration during/after deployment should be necessary). There should be a single "system of record" where a shared environment-dependent property is specified (such as a database connection string that is shared by many applications). Supports re-configuration of deployed applications (in the event that an environment-specific property needs to change), ideally without requiring a re-deployment of the application. Allows an application to be run on the same machine, but in different environments (run a PROD instance and a DEV instance simultaneously). Possible Solutions I see two basic directions in which a solution could go: Make all applications "environment aware". You would pass the environment name (DEV, QA, etc) at the command line to the app, and then the app is "smart" enough to figure out the environment-specific configuration values at run-time. The app could fetch the values from flat files deployed along with the app, or from a central configuration service. Applications are not "smart" as they are in #1, and simply fetch configuration by property name from config files deployed with the app. The values of these properties are injected into the config files at deploy-time by the install program/script. That install script takes the environment name and fetches all relevant configuration values from a central configuration service. Question How would/have you achieved a configuration solution that solves these problems and supports these desired features? Am I on target with the two possible solutions? Do you have a preference between those solutions? Also, please feel free to tell me that I'm thinking about the problem all wrong. Any feedback would be greatly appreciated.

    Read the article

  • functional dependencies vs type families

    - by mhwombat
    I'm developing a framework for running experiments with artificial life, and I'm trying to use type families instead of functional dependencies. Type families seems to be the preferred approach among Haskellers, but I've run into a situation where functional dependencies seem like a better fit. Am I missing a trick? Here's the design using type families. (This code compiles OK.) {-# LANGUAGE TypeFamilies, FlexibleContexts #-} import Control.Monad.State (StateT) class Agent a where agentId :: a -> String liveALittle :: Universe u => a -> StateT u IO a -- plus other functions class Universe u where type MyAgent u :: * withAgent :: (MyAgent u -> StateT u IO (MyAgent u)) -> String -> StateT u IO () -- plus other functions data SimpleUniverse = SimpleUniverse { mainDir :: FilePath -- plus other fields } defaultWithAgent :: (MyAgent u -> StateT u IO (MyAgent u)) -> String -> StateT u IO () defaultWithAgent = undefined -- stub -- plus default implementations for other functions -- -- In order to use my framework, the user will need to create a typeclass -- that implements the Agent class... -- data Bug = Bug String deriving (Show, Eq) instance Agent Bug where agentId (Bug s) = s liveALittle bug = return bug -- stub -- -- .. and they'll also need to make SimpleUniverse an instance of Universe -- for their agent type. -- instance Universe SimpleUniverse where type MyAgent SimpleUniverse = Bug withAgent = defaultWithAgent -- boilerplate -- plus similar boilerplate for other functions Is there a way to avoid forcing my users to write those last two lines of boilerplate? Compare with the version using fundeps, below, which seems to make things simpler for my users. (The use of UndecideableInstances may be a red flag.) (This code also compiles OK.) {-# LANGUAGE MultiParamTypeClasses, FunctionalDependencies, FlexibleInstances, UndecidableInstances #-} import Control.Monad.State (StateT) class Agent a where agentId :: a -> String liveALittle :: Universe u a => a -> StateT u IO a -- plus other functions class Universe u a | u -> a where withAgent :: Agent a => (a -> StateT u IO a) -> String -> StateT u IO () -- plus other functions data SimpleUniverse = SimpleUniverse { mainDir :: FilePath -- plus other fields } instance Universe SimpleUniverse a where withAgent = undefined -- stub -- plus implementations for other functions -- -- In order to use my framework, the user will need to create a typeclass -- that implements the Agent class... -- data Bug = Bug String deriving (Show, Eq) instance Agent Bug where agentId (Bug s) = s liveALittle bug = return bug -- stub -- -- And now my users only have to write stuff like... -- u :: SimpleUniverse u = SimpleUniverse "mydir"

    Read the article

  • (mySQL) Unable to query 2 tables properly for data

    - by Devner
    I have 2 tables. One is 'page_links' and the other is 'rpp'. Table page_links is the superset of table rpp. The following is the schema of my tables: -- Table structure for table `page_links` -- CREATE TABLE IF NOT EXISTS `page_links` ( `page` varchar(255) NOT NULL, `page_link` varchar(100) NOT NULL, `heading_id` tinyint(3) unsigned NOT NULL, PRIMARY KEY (`page`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; -- -- Dumping data for table `page_links` -- INSERT INTO `page_links` (`page`, `page_link`, `heading_id`) VALUES ('a1.php', 'A1', 8), ('b1.php', 'B1', 8), ('c1.php', 'C1', 5), ('d1.php', 'D1', 5), ('e1.php', 'E1', 8), ('f1.php', 'F1', 8), ('g1.php', 'G1', 8), ('h1.php', 'H1', 1), ('i1.php', 'I1', 1), ('j1.php', 'J1', 8), ('k1.php', 'K1', 8), ('l1.php', 'L1', 8), ('m1.php', 'M1', 8), ('n1.php', 'N1', 8), ('o1.php', 'O1', 8), ('p1.php', 'P1', 4), ('q1.php', 'Q1', 5), ('r1.php', 'R1', 4); -- Table structure for table `rpp` -- CREATE TABLE IF NOT EXISTS `rpp` ( `role_id` tinyint(3) unsigned NOT NULL, `page` varchar(255) NOT NULL, `is_allowed` tinyint(1) NOT NULL, PRIMARY KEY (`role_id`,`page`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; -- -- Dumping data for table `rpp` -- INSERT INTO `rpp` (`role_id`, `page`, `is_allowed`) VALUES (3, 'a1.php', 1), (3, 'b1.php', 1), (3, 'c1.php', 1), (3, 'd1.php', 1), (3, 'e1.php', 1), (3, 'f1.php', 1), (3, 'h1.php', 1), (3, 'i1.php', 1), (3, 'l1.php', 1), (3, 'm1.php', 1), (3, 'n1.php', 1), (4, 'a1.php', 1), (4, 'b1.php', 1), (4, 'q1.php', 1), (5, 'r1.php', 1); WHAT I AM TRYING TO DO: I am trying to query both the above tables (in a single query) in such a way that all the pages from page_links are displayed along with the is_allowed value from rpp for a particular role. For example, I want to get the is_allowed value of all the pages from rpp for role_id = 3 and at the same time, list all the available pages from page_links. A clear example of my expected result would be: page is_allowed role_id ---------------------------------------- a1.php 1 3 b1.php 1 3 c1.php 1 3 d1.php 1 3 e1.php 1 3 f1.php 1 3 g1.php NULL NULL h1.php 1 3 i1.php 1 3 j1.php NULL NULL k1.php NULL NULL l1.php 1 3 m1.php 1 3 n1.php 1 3 o1.php NULL NULL p1.php NULL NULL q1.php NULL NULL r1.php NULL NULL One more example of my desired result could be achieved by doing a LEFT JOIN rpp ON page_links.page = rpp.page but we need to omit using role_id = 3 (or any value) to be able to get that. But I do want to specify the role_id as well and get the results. I need the query to be able to get this result. I would appreciate any replies that could help me with this. If you can suggest me any changes as well to the table(s) design to be able to achieve the desired result, that's good as well. Thanks in advance.

    Read the article

  • Function returning MYSQL_ROW

    - by Gabe
    I'm working on a system using lots of MySQL queries and I'm running into some memory problems I'm pretty sure have to do with me not handling pointers right... Basically, I've got something like this: MYSQL_ROW function1() { string query="SELECT * FROM table limit 1;"; MYSQL_ROW return_row; mysql_init(&connection); // "connection" is a global variable if (mysql_real_connect(&connection,HOST,USER,PASS,DB,0,NULL,0)){ if (mysql_query(&connection,query.c_str())) cout << "Error: " << mysql_error(&connection); else{ resp = mysql_store_result(&connection); //"resp" is also global if (resp) return_row = mysql_fetch_row(resp); mysql_free_result(resp); } mysql_close(&connection); }else{ cout << "connection failed\n"; if (mysql_errno(&connection)) cout << "Error: " << mysql_errno(&connection) << " " << mysql_error(&connection); } return return_row; } And function2(): MYSQL_ROW function2(MYSQL_ROW row) { string query = "select * from table2 where code = '" + string(row[2]) + "'"; MYSQL_ROW retorno; mysql_init(&connection); if (mysql_real_connect(&connection,HOST,USER,PASS,DB,0,NULL,0)){ if (mysql_query(&connection,query.c_str())) cout << "Error: " << mysql_error(&conexao); else{ // My "debugging" shows me at this point `row[2]` is already fubar resp = mysql_store_result(&connection); if (resp) return_row = mysql_fetch_row(resp); mysql_free_result(resp); } mysql_close(&connection); }else{ cout << "connection failed\n"; if (mysql_errno(&connection)) cout << "Error : " << mysql_errno(&connection) << " " << mysql_error(&connection); } return return_row; } And main() is an infinite loop basically like this: int main( int argc, char* args[] ){ MYSQL_ROW row = NULL; while (1) { row = function1(); if(row != NULL) function2(row); } } (variable and function names have been generalized to protect the innocent) But after the 3rd or 4th call to function2, that only uses row for reading, row starts losing its value coming to a segfault error... Anyone's got any ideas why? I'm not sure the amount of global variables in this code is any good, but I didn't design it and only got until tomorrow to fix and finish it, so workarounds are welcome! Thanks!

    Read the article

  • c++ compile error

    - by Niranjan
    Hi, I am trying to develop abstract design pattern code for one of my project as below.. But, I am not able to compile the code ..giving some compile errors(like "conversion from 'ProductA1 *' to 'ProductA *' exists, but is inaccessible" ).. Can any one please help me out in this... #include "stdafx.h" #include <iostream> using namespace std; class ProductA { public: virtual void Operation1()=0; virtual void Operation2()=0; }; class ProductA1 : ProductA { public: virtual void Operation1() {cout<<"PD ProductA1 Operation1"<<endl; } virtual void Operation2() {cout<<"PD ProductA1 Operation2"<<endl; } }; class ProductA2 : ProductA { public: virtual void Operation1() {cout<<"DT ProductA2 Operation1"<<endl; } virtual void Operation2() {cout<<"DT ProductA2 Operation2"<<endl; } }; //------------------------------------------------------------- class ProductB { public: virtual void Operation3()=0; virtual void Operation4()=0; }; class ProductB1 : ProductB { public: void Operation3() { cout<<"PD ProductB1 Operation3"<<endl; } void Operation4() { cout<<"PD ProductB1 Operation4"<<endl; } }; class ProductB2 : ProductB { public: void Operation3() { cout<<"DT ProductB2 Operation3"<<endl; } void Operation4() { cout<<"DT ProductB2 Operation4"<<endl; } }; //--------------- abstrct factory --------------------------- class Factory { public: virtual ProductA* CreateA () =0; virtual ProductB* CreateB ()=0; }; class Factory1 : Factory { public: ProductA* CreateA () { return new ProductA1(); } ProductB* CreateB () { return new ProductB1(); } }; class Factory2 : Factory { public: ProductA* CreateA () { return new ProductA2(); } ProductB* CreateB () { return new ProductB2(); } }; //--------------------- client -------------------------------- int _tmain(int argc, _TCHAR* argv[]) { Factory* pf = new Factory1(); ProductA *pa = pf->CreateA(); pa->Operation1(); pa->Operation2(); ProductB *pb = pf->CreateB(); pb->Operation3(); pb->Operation4(); return 0; }

    Read the article

  • Rewriting Live TCP/IP (Layer 4) (i.e. Socket Layer) Streams

    - by user213060
    I have a simple problem which I'm sure someone here has done before... I want to rewrite Layer 4 TCP/IP streams (Not lower layer individual packets or frames.) Ettercap's etterfilter command lets you perform simple live replacements of Layer 4 TCP/IP streams based on fixed strings or regexes. Example ettercap scripting code: if (ip.proto == TCP && tcp.dst == 80) { if (search(DATA.data, "gzip")) { replace("gzip", " "); msg("whited out gzip\n"); } } if (ip.proto == TCP && tcp.dst == 80) { if (search(DATA.data, "deflate")) { replace("deflate", " "); msg("whited out deflate\n"); } } http://ettercap.sourceforge.net/forum/viewtopic.php?t=2833 I would like to rewrite streams based on my own filter program instead of just simple string replacements. Anyone have an idea of how to do this? Is there anything other than Ettercap that can do live replacement like this, maybe as a plugin to a VPN software or something? I would like to have a configuration similar to ettercap's silent bridged sniffing configuration between two Ethernet interfaces. This way I can silently filter traffic coming from either direction with no NATing problems. Note that my filter is an application that acts as a pipe filter, similar to the design of unix command-line filters: >[eth0] <----------> [my filter] <----------> [eth1]< What I am already aware of, but are not suitable: Tun/Tap - Works at the lower packet layer, I need to work with the higher layer streams. Ettercap - I can't find any way to do replacements other than the restricted capabilities in the example above. Hooking into some VPN software? - I just can't figure out which or exactly how. libnetfilter_queue - Works with lower layer packets, not TCP/IP streams. Again, the rewriting should occur at the transport layer (Layer 4) as it does in this example, instead of a lower layer packet-based approach. Exact code will help immensely! Thanks!

    Read the article

  • What's a clean way to have the server return a JavaScript function which would then be invoked?

    - by Khnle
    My application is architected as a host of plug-ins that have not yet been written. There's a long reason for this, but with each new year, the business logic will be different and we don't know what it will be like (Think of TurboTax if that helps). The plug-ins consist of both server and client components. The server components deals with business logic and persisting the data into database tables which will be created at a later time as well. The JavaScript manipulates the DOM for the browsers to render afterward. Each plugin lives in a separate assembly, so that they won't disturb the main application, i.e., we don't want to recompile the main application. Long story short, I am looking for a way to return JavaScript functions to the client from an Ajax get request, and execute these JavaScript functions (which are just returned). Invoking a function in Javascript is easy. The hard part is how to organize or structure so that I won't have to deal with maintenance problem. So concat using StringBuilder to end up with JavaScript code as a result of calling toString() from the string builder object is out of the question. I want to have no difference between writing JavaScript codes normally and writing Javascript codes for this dynamic purpose. An alternative is to manipulate the DOM on the server side, but I doubt that it would be as elegantly as using jQuery on the client side. I am open for a C# library that supports chainable calls like jQuery that also manipulates the DOM too. Do you have any idea or is it too much to ask or are you too confused? Edit1: The point is to avoid recompiling, hence the plug-ins architecture. In some other parts of the program, I already use the concept of dynamically loading Javascript files. That works fine. What I am looking here is somewhere in the middle of the program when an Ajax request is sent to the server. Edit 2: To illustrate my question: Normally, you would see the following code. An Ajax request is sent to the server, a JSON result is returned to the client which then uses jQuery to manipulate the DOM (creating tag and adding to the container in this case). $.ajax({ type: 'get', url: someUrl, data: {'': ''}, success: function(data) { var ul = $('<ul>').appendTo(container); var decoded = $.parseJSON(data); $.each(decoded, function(i, e) { var li = $('<li>').text(e.FIELD1 + ',' + e.FIELD2 + ',' + e.FIELD3); ul.append(li); }); } }); The above is extremely simple. But next year, what the server returns is totally different and how the data to be rendered would also be different. In a way, this is what I want: var container = $('#some-existing-element-on-the-page'); $.ajax({ type: 'get', url: someUrl, data: {'': ''}, success: function(data) { var decoded = $.parseJSON(data); var fx = decoded.fx; var data = decode.data; //fx is the dynamic function that create the DOM from the data and append to the existing container fx(container, data); } }); I don't need to know, at this time what data would be like, but in the future I will, and I can then write fx accordingly.

    Read the article

  • how to user ajax with json in ruby on rails

    - by fenec
    I am implemeting a facebook application in rails using facebooker plugin, therefore it is very important to use this architecture if i want to update multiple DOM in my page. if my code works in a regular rails application it would work in my facebook application. i am trying to use ajax to let the user know that the comment was sent, and update the comments bloc. migration: class CreateComments < ActiveRecord::Migration def self.up create_table :comments do |t| t.string :body t.timestamps end end def self.down drop_table :comments end end controller: class CommentsController < ApplicationController def index @comments=Comment.all end def create @comment=Comment.create(params[:comment]) if request.xhr? @comments=Comment.all render :json=>{:ids_to_update=>[:all_comments,:form_message], :all_comments=>render_to_string(:partial=>"comments" ), :form_message=>"Your comment has been added." } else redirect_to comments_url end end end view: <script> function update_count(str,message_id) { len=str.length; if (len < 200) { $(message_id).innerHTML="<span style='color: green'>"+ (200-len)+" remaining</span>"; } else { $(message_id).innerHTML="<span style='color: red'>"+ "Comment too long. Only 200 characters allowed.</span>"; } } function update_multiple(json) { for( var i=0; i<json["ids_to_update"].length; i++ ) { id=json["ids_to_update"][i]; $(id).innerHTML=json[id]; } } </script> <div id="all_comments" > <%= render :partial=>"comments/comments" %> </div> Talk some trash: <br /> <% remote_form_for Comment.new, :url=>comments_url, :success=>"update_multiple(request)" do |f|%> <%= f.text_area :body, :onchange=>"update_count(this.getValue(),'remaining');" , :onkeyup=>"update_count(this.getValue(),'remaining');" %> <br /> <%= f.submit 'Post'%> <% end %> <p id="remaining" >&nbsp;</p> <p id="form_message" >&nbsp;</p> <br><br> <br> if i try to do alert(json) in the first line of the update_multiple function , i got an [object Object]. if i try to do alert(json["ids_to_update"][0]) in the first line of the update_multiple function , there is no dialog box displayed. however the comment got saved but nothing is updated. questions: 1.how can javascript and rails know that i am dealing with json objects? 2.how can i debug this problem? 3.how can i get it to work?

    Read the article

  • Clearcase - selective merge.

    - by Keshav
    Hi, I have a peculiar Clearcase doubt. I cannot fully describe why I'm doing such a confusing architecture, but I need to do it (thanks to the mistake done by someone long back). Ok, here's a bit of detail: B1 is a contaminated branch where both my group's changes and another group's changes got mixed together so badly that there is no way of finding which code is whose). So the solution proposed is to create a new branch called B2 (at the same level as B1) and put all the unmodified code of the other group on it (The way to do that would be to merge B1 with B2 and then go about removing all changes from it till it becomes original). Then create a CR branch on B1 and keep only my group's newly added files or modified files on that branch. Finally create an integration branch out of B2 and merge the changes from CR branch of B1 to integration branch of B2. So here is what I did: (The use case is where I have dir D where file a, b and c are there. My group ended up modifying file a while b and c are not modified at all). There is a branch B1 on which there are files a, b and c. There is another branch B2. A merge is done from B1 to B2. Now B2 also has a, b and c. At this point both branch B1 and B2 are same. Now I delete file a from branch B2 (rmname). Now B2 has b and c only. I put a label to this branch called Label1. This makes the code with label Label1 as the unmodified code from other group. Now I create a sub branch called CR1 from B1 and delete all the files that are there in B2 branch (i.e b and c) such that it contains only the modified code from original code on it. In my case it is file a. At this point branch B2 with label Label1 has files b and c (those are unmodified code) and branch CR1 coming off B1 has only a (that is modified by us). Now I create another branch called integration branch that comes off B2 Label1. And then I do a merge of CR branch on to that expecting that it will have all three files a, b and c for me. All I'd need to do is to do a version tree view and see who modified what. But the problem I face is that since I had done a rmname of file a on branch B2 earlier to putting Label. The merge does not really take the file a from CR branch. How to I get around that problem. I want to selectively merge. Is it possible? sorry if it is a bad design. I'm not really conversant with Clear case and have limited options and time to clear some one else's mess.

    Read the article

  • WinForm-style Invoke() in unmanaged C++

    - by Matt Green
    I've been playing with a DataBus-type design for a hobby project, and I ran into an issue. Back-end components need to notify the UI that something has happened. My implementation of the bus delivers the messages synchronously with respect to the sender. In other words, when you call Send(), the method blocks until all the handlers have called. (This allows callers to use stack memory management for event objects.) However, consider the case where an event handler updates the GUI in response to an event. If the handler is called, and the message sender lives on another thread, then the handler cannot update the GUI due to Win32's GUI elements having thread affinity. More dynamic platforms such as .NET allow you to handle this by calling a special Invoke() method to move the method call (and the arguments) to the UI thread. I'm guessing they use the .NET parking window or the like for these sorts of things. A morbid curiosity was born: can we do this in C++, even if we limit the scope of the problem? Can we make it nicer than existing solutions? I know Qt does something similar with the moveToThread() function. By nicer, I'll mention that I'm specifically trying to avoid code of the following form: if(! this->IsUIThread()) { Invoke(MainWindowPresenter::OnTracksAdded, e); return; } being at the top of every UI method. This dance was common in WinForms when dealing with this issue. I think this sort of concern should be isolated from the domain-specific code and a wrapper object made to deal with it. My implementation consists of: DeferredFunction - functor that stores the target method in a FastDelegate, and deep copies the single event argument. This is the object that is sent across thread boundaries. UIEventHandler - responsible for dispatching a single event from the bus. When the Execute() method is called, it checks the thread ID. If it does not match the UI thread ID (set at construction time), a DeferredFunction is allocated on the heap with the instance, method, and event argument. A pointer to it is sent to the UI thread via PostThreadMessage(). Finally, a hook function for the thread's message pump is used to call the DeferredFunction and de-allocate it. Alternatively, I can use a message loop filter, since my UI framework (WTL) supports them. Ultimately, is this a good idea? The whole message hooking thing makes me leery. The intent is certainly noble, but are there are any pitfalls I should know about? Or is there an easier way to do this?

    Read the article

  • How to override loading a TImage from the object inspector (at run-time)?

    - by Mawg
    Further to my previous question, which did not get a useful answer despite a bounty, I will try rephrasing the question. Basically, when the user clicks the ellipsis in the object inspector, Delphi opens a file/open dialog. I want to replace this handling with my own, so that I can save the image's path. I would have expected that all I need to do is to derive a class from TImage and override the Assign() function, as in the following code. However, when I do the assign function is never called. So, it looks like I need to override something else, but what? unit my_Image; interface uses Classes, ExtCtrls, Jpeg, Graphics; type Tmy_Image = class(Timage) private FPicture : TPicture; protected procedure OnChange(Sender: TObject); public { Public declarations } Constructor Create(AOwner: TComponent); override; procedure SetPicture(picture : TPicture); procedure Assign(Source: TPersistent); override; published { Published declarations - available in the Object Inspector at design-time } property Picture : TPicture read FPicture write SetPicture; end; // of class Tmy_Image() procedure Register; implementation uses Controls, Dialogs; procedure Register; begin RegisterComponents('Standard', [Tmy_Image]); end; Constructor Tmy_Image.Create(AOwner: TComponent); begin inherited; // Call the parent Create method Hint := 'Add an image from a file|Add an image from a file'; // Tooltip | status bar text AutoSize := True; // Control resizes when contents change (new image is loaded) Height := 104; Width := 104; FPicture := TPicture.Create(); self.Picture.Bitmap.LoadFromResourceName(hInstance, 'picture_poperty_bmp'); end; procedure Tmy_Image.OnChange(Sender: TObject); begin Constraints.MaxHeight := Picture.Height; Constraints.MaxWidth := Picture.Width; Self.Height := Picture.Height; Self.Width := Picture.Width; end; procedure Tmy_Image.SetPicture(picture : TPicture); begin MessageDlg('Tmy_Image.SetPicture', mtWarning, [mbOK], 0); // never called end; procedure Tmy_Image.Assign(Source: TPersistent); begin MessageDlg('Tmy_Image.Assign', mtWarning, [mbOK], 0); // never called end; end.

    Read the article

< Previous Page | 651 652 653 654 655 656 657 658 659 660 661 662  | Next Page >