Search Results

Search found 4772 results on 191 pages for 'complex'.

Page 149/191 | < Previous Page | 145 146 147 148 149 150 151 152 153 154 155 156  | Next Page >

• Performance issue on Android's MapView Navigation-App

  - by poeschlorn

  Hey Guys, I've got a question on making an navigation app more faster and more stable. The basic layer of my app is a simple mapview, covered with several overlays (2 markers for start and destination and one for the route). My idea is to implement a thread to display the route, so that the app won't hang up during the calculation of a more complex route (like it does right now). After implementing the thread there are no updates shows any more, maybe you can help me with a short glance at an excerpt of my code below: private class MyLocationListener implements LocationListener { @Override public void onLocationChanged(Location loc) { posUser = new GeoPoint((int) (loc.getLatitude() * 1E6), (int) (loc .getLongitude() * 1E6)); new Thread(){ public void run(){ mapView.invalidate(); // Erase old overlays mapView.getOverlays().clear(); // Draw updated overlay elements and adjust basic map settings updateText(); if(firstRefresh){ adjustMap(); firstRefresh = false; } getAndPaintRoute(); drawMarkers(); } }; } Some features have been summarized to a method like "drawMarkers()" or "updateText()"...(they don't need any more attention ;-))

  Read the article

• what exactly is the danger of an uninitialized pointer in C

  - by akh2103

  I am trying get a handle on C as I work my way thru Jim Trevor's "Cyclone: A safe dialect of C" for a PL class. Trevor and his co-authors are trying to make a safe version of C, so they eliminate uninitialized pointers in their language. Googling around a bit on uninitialized pointers, it seems like un-initialized pointers point to random locations in memory. It seems like this alone makes them unsafe. If you reference an un-itilialized pointer, you jump to an unsafe part of memory. Period. But the way Trevor talks about them seems to imply that it is more complex. He cites the following code, and explains that when the function FrmGetObjectIndex dereferences f, it isn’t accessing a valid pointer, but rather an unpredictable address — whatever was on the stack when the space for f was allocated. What does Trevor mean by "whatever was on the stack when the space for f was allocated"? Are "un-initialized" pointers initialized to random locations in memory by default? Or does their "random" behavior have to do with the memory allocated for these pointers getting filled with strange values (that are then referenced) because of unexpected behavior on the stack. Form *f; switch (event->eType) { case frmOpenEvent: f = FrmGetActiveForm(); ... case ctlSelectEvent: i = FrmGetObjectIndex(f, field); ... }

  Read the article

• Drawing a relative line in C#

  - by icemanind

  Guys, I know this is going to turn out to be a simple answer, but I can't seem to figure it out. I have a C# Winform application that I am trying to build. I am trying to draw a white line 60 pixels above the bottom of the form. I am using this code: private void MainForm_Paint(object sender, PaintEventArgs e) { e.Graphics.DrawLine(Pens.White, 10, this.Height-60, 505, this.Height-60); } Simple enough, however no line is drawn. After some debugging, I figured out that it IS drawing the line, but it is drawing it outside my form. If I change the -60 to -175, then I can see it at the bottom of my form. This would solve my problem, except as my form's height changes, the line draws closer and closer to the bottom of my form until eventually, its off the form again. What am I doing wrong? Am I using the wrong graphics unit? Or is there a more complex calculation I need to do to determine 60 pixels from the bottom of my form?

  Read the article

• Saving "heavy" figure to PDF in MATLAB - rendering problem

  - by yuk

  I generate a figure in MATLAB with lot amount of points (100000+) and want to save it into a PDF file. With zbuffer or painters renderer I've got very large and slowly opened file (over 4 Mb) - all points are in vector format. Using OpenGL renderer rasterize the figure in PDF, ok for the plot, but not good for text labels. The file size is about 150 Kb. Try this simplified code, for example: x=linspace(1,10,100000); y=sin(x)+randn(size(x)); plot(x,y,'.') set(gcf,'Renderer','zbuffer') print -dpdf -r300 testpdf_zb set(gcf,'Renderer','painters') print -dpdf -r300 testpdf_pa set(gcf,'Renderer','opengl') print -dpdf -r300 testpdf_op The actual figure is much more complex with several axes and different types of plots. Is there a way to rasterize the figure, but keep text labels as vectors? Another problem with OpenGL is that is does not work in terminal mode (-nosplash -nodesktop) under Mac OSX. Looks like OpenGL is not supported. I have to use terminal mode for automation. The MATLAB version I run is 2007b. Mac OSX server 10.4.

  Read the article

• How to customize RESTful Routes in Rails (basics)

  - by viatropos

  I have read through the Rails docs for Routing, Restful Resources, and the UrlHelper, and still don't understand best practices for creating complex/nested routes. The example I'm working on now is for events, which has_many rsvps. So a user's looking through a list of events, and clicks register, and goes through a registration process, etc. I want the urls to look like this: /events /events/123 # possible without title, like SO /events/123/my-event-title # canonical version /events/my-category/123/my-event-title # also possible like this /events/123/my-event-title/registration/new ... and all the restful nested resouces. Question is, how do I accomplish this with the minimal amount of code? Here's what I currently have: map.resources :events do |event| event.resources :rsvps, :as => "registration" end That gets me this: /events/123/registration What's the best way to accomplish the other 2 routes? /events/123/my-event-title # canonical version /events/my-category/123/my-event-title # also possible like this Where my-category is just an array of 10 possible types the event can be. I've modified Event#to_param to return "#{self.id.to_s}-#{self.title.parameterize}", but I'd prefer to have /id/title with the whole canonical-ness

  Read the article

• Hibernate and parent/child relations

  - by Marco

  Hi to all, I'm using Hibernate in a Java application, and i feel that something could be done better for the management of parent/child relationships. I've a complex set of entities, that have some kind of relationships between them (one-to-many, many-to-many, one-to-one, both unidirectional and bidirectional). Every time an entity is saved and it has a parent, to estabilish the relationship the parent has to add the child to its collection (considering a one-to-may relationship). For example: Parent p = (Parent) session.load(Parent.class, pid); Child c = new Child(); c.setParent(p); p.getChildren().add(c); session.save(c); session.flush(); In the same way, if i remove a child then i have to explicitly remove it from the parent collection too. Child c = (Child) session.load(Child.class, cid); session.delete(c); Parent p = (Parent) session.load(Parent.class, pid); p.getChildren().remove(c); session.flush(); I was wondering if there are some best practices out there to do this jobs in a different way: when i save a child entity, automatically add it to the parent collection. If i remove a child, automatically update the parent collection by removing the child, etc. For example, Child c = new Child(); c.setParent(p); session.save(c); // Automatically update the parent collection session.flush(); or Child c = (Child) session.load(Child.class, cid); session.delete(c); // Automatically updates its parents (could be more than one) session.flush(); Anyway, it would not be difficult to implement this behaviour, but i was wondering if exist some standard tools or well known libraries that deals with this issue. And, if not, what are the reasons? Thanks

  Read the article

• Building a custom (dynamic) dataset and grid

  - by marko.ivanovski.nz

  Hi, I'm in the process of building a dynamic table in which you can add/remove rows & columns so it varies in size depending on what the user wants. Its purpose is to store properties for a product, but there can be from 1 to 10 different properties(columns) per product, and multiple instances(rows) of the product as well. Here's a screenshot of what I mean http://i40.tinypic.com/nbqkxc.jpg As you can see I need the structure to be completely up to the client which is where I'm getting stuck. I've started writing a custom DataSet that has "add column" & "add row" buttons, and have built a custom Table with Textboxes in each cell which builds from that dataset. I have no idea how to store the data on submit though, and to make it even more complex I need to store this in the database as a string which I think I can do by converting it to XML. Any help is appreciated, I think I just need a pointer in the right direction and am happy to do research from there. Thanks in advance. Marko

  Read the article

• How do You Center a TextView in Layout?

  - by Ken

  I have a complex layout, part of which features a value centered over a label, with + and - buttons on either side of the value. I want the value to center between the buttons, whether it is "1" or "99". It looks fine when it's a 2-digit number like "99", but when it's a single digit the number is left-justified. How do I properly center that value? Here's the portion of my layout that does this: <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_above="@id/runway_label" android:layout_centerHorizontal="true" android:orientation="horizontal"> <ImageView android:id="@+id/dec_runway_button" android:src="@drawable/minus_button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical"/> <TextView android:id="@+id/runway_value" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textColor="#FFFFFF" android:textStyle="bold" android:textSize="40.0sp" android:minWidth="50sp" android:layout_centerInParent="true" android:layout_gravity="center" android:shadowColor="#333333" android:shadowDx="2.0" android:shadowDy="2.0" android:shadowRadius="3.0" /> <ImageView android:id="@+id/inc_runway_button" android:src="@drawable/plus_button" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_vertical"/> </LinearLayout>

  Read the article

• restrict documents for mapreduce with mongoid

  - by theBernd

  I implemented the pearson product correlation via map / reduce / finalize. The missing part is to restrict the documents (representing users) to be processed via a filter query. For a simple query like mapreduce(mapper, reducer, :finalize => finalizer, :query => { :name => 'Bernd' }) I get this to work. But my filter criteria is a little bit more complicated: I have one set of preferences which need to have at least one common element and another set of preferences which may not have a common element. In a later step I also want to restrict this to documents (users) within a certain geographical distance. Currently I have this code working in my map function, but I would prefer to separate this into either query params as supported by mongoid or a javascript function. All my attempts to solve this failed since the code is either ignored or raises an error. I did a couple of tests. A regular find like User.where(:name.in => ['Arno', 'Bernd', 'Claudia']) works and returns #<Mongoid::Criteria:0x00000101f0ea40 @selector={:name=>{"$in"=>["Arno", "Bernd", "Claudia"]}}, @options={}, @klass=User, @documents=[]> Trying the same with mapreduce User.collection. mapreduce(mapper, reducer, :finalize => finalizer, :query => { :name.in => ['Arno', 'Bernd', 'Claudia'] }) fails with `serialize': keys must be strings or symbols (TypeError) in bson-1.1.5 The intermediate query parameter looks like this :query=>{#<Mongoid::Criterion::Complex:0x00000101a209e8 @key=:name, @operator="in">=>["Arno", "Bernd", "Claudia"]} and at least @operator looks a bit weird to me. I'm also uncertain if the class name can be omitted. BTW - I'm using mongodb 1.6.5-x86_64, and the mongoid 2.0.0.beta.20, mongo 1.1.5 and bson 1.1.5 gems on MacOS. What am I doing wrong? Thanks in advance.

  Read the article

• Is there some advantage to filling a stack with nils and interpreting the "top" as the last non-nil value?

  - by dwilbank

  While working on a rubymonk exercise, I am asked to implement a stack with a hard size limit. It should return 'nil' if I try to push too many values, or if I try to pop an empty stack. My solution is below, followed by their solution. Mine passes every test I can give it in my IDE, while it fails rubymonk's test. But that isn't my question. Question is, why did they choose to fill the stack with nils instead of letting it shrink and grow like it does in my version? It just makes their code more complex. Here's my solution: class Stack def initialize(size) @max = size @store = Array.new end def pop empty? ? nil : @store.pop end def push(element) return nil if full? @store.push(element) end def size @store.size end def look @store.last end private def full? @store.size == @max end def empty? @store.size == 0 end end and here is the accepted answer class Stack def initialize(size) @size = size @store = Array.new(@size) @top = -1 end def pop if empty? nil else popped = @store[@top] @store[@top] = nil @top = @top.pred popped end end def push(element) if full? or element.nil? nil else @top = @top.succ @store[@top] = element self end end def size @size end def look @store[@top] end private def full? @top == (@size - 1) end def empty? @top == -1 end end

  Read the article

• Treetop basic parsing and regular expression usage

  - by ucint

  I'm developing a script using the ruby Treetop library and having issues working with its syntax for regex's. First off, many regular expressions that work in other settings dont work the same in treetop. This is my grammar: (myline.treetop) grammar MyLine rule line string whitespace condition end rule string [\S]* end rule whitespace [\s]* end rule condition "new" / "old" / "used" end end This is my usage: (usage.rb) require 'rubygems' require 'treetop' require 'polyglot' require 'myline' parser = MyLineParser.new p parser.parse("randomstring new") This should find the word new for sure and it does! Now I wont to extend it so that it can find new if the input string becomes "randomstring anotherstring new yetanother andanother" and possibly have any number of strings followed by whitespace (tab included) before and after the regex for rule condition. In other words, if I pass it any sentence with the word "new" etc in it, it should be able to match it. So let's say I change my grammar to: rule line string whitespace condition whitespace string end Then, it should be able to find a match for: p parser.parse("randomstring new anotherstring") So, what do I have to do to allow the string whitespace to be repeated before and after condition? If I try to write this: rule line (string whitespace)* condition (whitespace string)* end , it goes in an infinite loop. If i replace the above () with [], it returns nil In general, regex's return a match when i use the above, but treetop regex's dont. Does anyone have any tips/points on how to go about this? Plus, since there isn't much documentation for treetop and the examples are either too trivial or too complex, is there anyone who knows a more thorough documentation/guide for treetop?

  Read the article

• Goal setting/tracking packages

  - by Avi

  I'm a developer working by myself. I'm looking for a computerized tool to manage my goals and activities. I own it Microsoft Project, but I don't like it. I've started many "projects" but could never keep on using it. Too complex and heavyweight for me. I use MS-Outlook tasks. They are not what I need. No planning capability. Tracking is not nice. I'm using the Pomodoro technique and I like it, but I'm looking for something more comprehensive and with better computerized support. Something that would allow me to define goals with dependencies and time estimation, keep daily prioritized lists etc. So, I'm looking for a solution. One I've found is GoalPro, but I don't like the fact I could not find a "top ten comparison". Are you using any goal setting package such as GoalPro? Which? Does it help? Pros and Cons?

  Read the article

• In .NET when Aborting Thread, can this piece of code get corrupted?

  - by bosko

  Little intro: In complex multithreaded aplication (enterprise service bus EBS), I need to use Thread.Abort, because this EBS accepts user written modules which communicates with hardware security modules. So if this module gets deadlocked or hardware stops responding - i need to just unload this module and rest of this server aplication must keep runnnig. So there is abort sync mechanism which ensures that code can be aborted only in user section and this section must be marked as AbortAble. If this happen there is possibility that ThreadAbortException will be thrown in this pieace of code: public void StopAbortSection() { var id = Thread.CurrentThread.ManagedThreadId; lock (threadIdMap[id]) { .... } } If module is on AbortSection and Aplication decides to abort module, but after this decision but before actual Thread.Abort, module enters NonAbortableSection by calling this method, but lock is actualy taken on that locking object. So lock will block until Abort or abort can be executed before reaching this block by this code. But Object with this method is essential and i need to be sure that this pieace of code is safe to abort in any moment. Probably i have to mention that threadIdMap is Dictionary(int,ManualResetEvent), so locking object is instance of ManualResetEvent. I hope you now understad my question. Sorry for its largeness.

  Read the article

• Appropriate wx.Sizer(s) for the job?

  - by MetaHyperBolic

  I have a space in which I would like certain elements (represented here by A, B, D, and G) to each be in its own "corner" of the design. The corners ought to line up as if each of the four elements was repelling the other; a rectangle. This is to be contained within an unresizable panel. I will have several similar panels and want to keep the location of the elements as identical as possible. (I needed something a little more complex than a wx.Wizard, but with the same general idea.) AAAAAAAAAA BB CCCCCCCCCCCCCCCCCC CCCCCCCCCCCCCCCCCC CCCCCCCCCCCCCCCC CCCCCCCCCCCCCC CCCCCCCCCCCCCCCCCC CCCCCCCCCCCCCCCC CCCCCCCCCCCCCCCCCC DDD EEE FFF GGG A represents a text in a large font. B represents a numeric progress meter (e.g. "1 of 7") in a small font. C represents a large block of text. D, E, F, and G are buttons. The G button is separated from others for functionality. I have attempted nested wx.BoxSizers (horizontal boxes inside of one vertical box) without luck. My first problem with wx.BoxSizer is that the .SetMinSize on my last row has not been honored. The second problem is that I have no idea how to make the G button "take up space" without growing comically large, or how I can jam it up against the right edge and bottom edge. I have tried to use a wx.GridBagSizer, but ran into entirely different issues. After plowing through the various online tutorials and wxPython in Action, I'm a little frustrated. The relevant forums appear to see activity once every two weeks. "Playing around with it" has gotten me nowhere; I feel as if I am trying to smooth out a hump in ill-laid carpet.

  Read the article

• how to use a generated dbml classes to deserialize xml via linq?

  - by Eelco Meuter

  Hi, I have a complex data structure, which I boiled down in a dbml file with one class and 6 one-to-many relations. This data must also be read via xml. The xml structure is something like: <table id=1> <column 1></column 1> <column n></column n> <m-n table x> <column 1></column 1> </m-n table x> </table> where the tag <m-n table x> is one of the six related tables. The idea is to generate an xsd based upon the dbml, which I can use to create and validate a xml. This xml can hopefully deserialized into the dbml classes. The question is: Can this be done? If so, how do I generate the xsd. I use a sql server express 2008 r2 as backend. Thanks in advance for your time!

  Read the article

• php user authentication libraries / frameworks ... what are the options?

  - by es11

  I am using PHP and the codeigniter framework for a project I am working on, and require a user login/authentication system. For now I'd rather not use SSL (might be overkill and the fact that I am using shared hosting discourages this). I have considered using openID but decided that since my target audience is generally not technical, it might scare users away (not to mention that it requires mirroring of login information etc.). I know that I could write a hash based authentication (such as sha1) since there is no sensitive data being passed (I'd compare the level of sensitivity to that of stackoverflow). That being said, before making a custom solution, it would be nice to know if there are any good libraries or packages out there that you have used to provide semi-secure authentication? I am new to codeigniter, but something that integrates well with it would be preferable. Any ideas? (i'm open to criticism on my approach and open to suggestions as to why I might be crazy not to just use ssl). Thanks in advance. Update: I've looked into some of the suggestions. I am curious to try out zend-auth since it seems well supported and well built. Does anyone have experience with using zend-auth in codeigniter (is it too bulky?) and do you have a good reference on integrating it with CI? I do not need any complex authentication schemes..just a simple login/logout/password-management authorization system. Also, dx_auth seems interesting as well, however I am worried that it is too buggy. Has anybody else had success with this? I realized that I would also like to manage guest users (i.e. users that do not login/register) in a similar way to stackoverflow..so any suggestions that have this functionality would be great

  Read the article

• Can I use the auto-generated Linq-to-SQL entity classes in 'disconnected' mode?

  - by Gary McGill

  Suppose I have an automatically-generated Employee class based on the Employees table in my database. Now suppose that I want to pass employee data to a ShowAges method that will print out name & age for a list of employees. I'll retrieve the data for a given set of employees via a linq query, which will return me a set of Employee instances. I can then pass the Employee instances to the ShowAges method, which can access the Name & Age fields to get the data it needs. However, because my Employees table has relationships with various other tables in my database, my Employee class also has a Department field, a Manager field, etc. that provide access to related records in those other tables. If the ShowAges method were to invoke any of those methods, this would cause lots more data to be fetched from the database, on-demand. I want to be sure that the ShowAges method only uses the data I have already fetched for it, but I really don't want to have to go to the trouble of defining a new class which replicates the Employee class but has fewer methods. (In my real-world scenario, the class would have to be considerably more complex than the Employee class described here; it would have several 'joined' classes that do need to be populated, and others that don't). Is there a way to 'switch off' or 'disconnect' the Employees instances so that an attempt to access any property or related object that's not already populated will raise an exception? If not, then I assume that since this must be a common requirement, there might be an already-established pattern for doing this sort of thing?

  Read the article

• how to associate the activemq-core.xsd url with the activemq.xsd found in the jar file?

  - by livia

  Hello, Somebody knows how to associate the activemq-core.xsd url with the activemq.xsd found in the jar file (activemq-core-5.2.0.jar)? I dig some solution in internet but didn't work. I'm getting this error: Caused by: org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 19 in XML document from class path resource [jms-context.xml] is invalid; nested exception is org.xml.sax.SAXParseException: cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'amq:broker'. at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:404) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:342) at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:310) at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:143) at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:178) at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:149) at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:212) at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:81) at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:42) at org.springframework.test.context.TestContext.loadApplicationContext(TestContext.java:173) at org.springframework.test.context.TestContext.getApplicationContext(TestContext.java:197) This shoud me hapening because we remove the URL from the schemaLocation (http://activemq.apache.org/schema/core classpath:activemq.xsd), and we are using localy. But I don't know why XML are not finding the activemq.xsd during the build process. I add the JAR file in the classpath, should not work like that?? Thanks in advance for any help

  Read the article

• Building a formset dynamically

  - by vorpyg

  I initially wrote code to build a form dynamically, based on data from the DB, similar to what I described in my previous SO post. As SO user Daniel Roseman points out, he would use a formset for this, and now I've come to the realization that he must be completely right. :) My approach works, basically, but I can't seem to get validation across the entire form to be working properly (I believe it's possible, but it's getting quite complex, and there has to be a smarter way of doing it = Formsets!). So now my question is: How can I build a formset dynamically? Not in an AJAX way, I want each form's label to be populated with an FK value (team) from the DB. As I have a need for passing parameters to the form, I've used this technique from a previous SO post. With the former approach, my view code is (form code in previous link): def render_form(request): teams = Team.objects.filter(game=game) form_collection = [] for team in teams: f = SuggestionForm(request.POST or None, team=team, user=request.user) form_collection.append(f) Now I want to do something like: def render_form(request): teams = Team.objects.filter(game=game) from django.utils.functional import curry from django.forms.formsets import formset_factory formset = formset_factory(SuggestionForm) for team in teams: formset.form.append(staticmethod(curry(SuggestionForm, request.POST or None, team=team, user=request.user))) But the append bit doesn't work. What's the proper way of doing this? Thanks!

  Read the article

• Is there a Post-Build Extensible Installer System

  - by Will Hughes

  We have a product that we need to create an installer for. It has a number of components which can be installed or not as the situation demands. When we ship our installation package, we want to be able to have that include any number of additional components to be installed. For example, Foo Manager Pro contains: Foo Manager Console Foo Manager Database Foo Manager Services That might be shipped as something like: FooManagerInstaller.exe FMPConsole.pkg FMPDatabase.pkg FMPServices.pkg A package might consist of something like: Manifest Files to be deployed Additional scripts to be executed (eg find file foo.config, do some XML Manipulation) If a client wants to add custom skins and a series of plugins as part of the install, they create their own packages: FMPConsoleSkins.pkg ClientWebservices.pkg If that client then ships it to someone else who wants to add more customisation - they can do so in the same way. We can build this from scratch - but wanted to check if this sort of install system already exists. We already have a set of NAnt scripts which do something not too far from this. But they're difficult to maintain, and quite complex. They don't offer any of the 'niceties' that we'd expect from an installer (like tracking deployed files and removing them if the install fails). We've been looking a little bit at NSIS and building MSIs using WiX, but it's not clear that these can offer us the capability for downstream to provide additional packages, without inventing our own installer language.

  Read the article

• Java method keyword "final" and its use

  - by Lukas Eder

  When I create complex type hierarchies (several levels, several types per level), I like to use the final keyword on methods implementing some interface declaration. An example: interface Garble { int zork(); } interface Gnarf extends Garble { /** * This is the same as calling {@link #zblah(0)} */ int zblah(); int zblah(int defaultZblah); } And then abstract class AbstractGarble implements Garble { @Override public final int zork() { ... } } abstract class AbstractGnarf extends AbstractGarble implements Gnarf { // Here I absolutely want to fix the default behaviour of zblah // No Gnarf shouldn't be allowed to set 1 as the default, for instance @Override public final int zblah() { return zblah(0); } // This method is not implemented here, but in a subclass @Override public abstract int zblah(int defaultZblah); } I do this for several reasons: It helps me develop the type hierarchy. When I add a class to the hierarchy, it is very clear, what methods I have to implement, and what methods I may not override (in case I forgot the details about the hierarchy) I think overriding concrete stuff is bad according to design principles and patterns, such as the template method pattern. I don't want other developers or my users do it. So the final keyword works perfectly for me. My question is: Why is it used so rarely in the wild? Can you show me some examples / reasons where final (in a similar case to mine) would be very bad?

  Read the article

• Best strategy for moving data between physical tiers in ASP.net

  - by Pete Lunenfeld

  Building a new ASP.net application, and planning to separate DB, 'service' tier and Web/UI tier into separate physical layers. What is the best/easiest strategy to move serialized objects between the service tier and the UI tier? I was considering serializing POCOs into JSON using simple ASP.net pages to serve the middle tier. Meaning that the UI/Web tier will request data from a (hidden to the outside user) web server that will return a JSON string. This kind of JSON 'emitter' seems easily testable. It also seems easily compressible for efficiently moving data over the WAN between tiers. I know that some folks use .asmx webservices for this kind of task, but this seems like there is excess overhead with SOAP, and the package is not as human readable (testable) as POCOs serialized as JSON. Others are using more complex technology like WCF which we have never used. Does anyone have advice for choosing a method for moving data/objects between the data (db) tier and the web (UI) tier over the WAN using .net technologies? Thanks!!!

  Read the article

• Get notified when objective-c dom updates are ready initiated from webview

  - by Josh

  I am programmatically updating the DOM on a WebKit webview via DOMElement objects - for complex UI, there is usually a javascript component to any element that I add. This begs the need to be notified when the updates complete -- is there any such event? I know regular divs dont fire an onload or onready event, correct? The other assumption I had, which may be totally wrong, is that DOMElement updates aren't synchronous, so I can't do something like this and be confident it will meet with the label actually in the DOM: DOMElement *displayNameLabel = [document createElement:@"div"]; [displayNameLabel setAttribute:@"class" value:@"user-display-name"]; [displayNameLabel setTextContent:currentAvatar.avatarData.displayName]; [[document getElementById:@"user-card-content"] appendChild:displayNameLabel]; id win = [webView windowScriptObject]; [win evaluateWebScript:@"javascriptInstantiateLabel()"]; Is this true? I am using jquery within the body of the html already, so I don't mind subscribing to a particular classes set of events via "live." I thought I might be able to do something like: $(".some-class-to-be-added-later").live( "ready", function(){ // Instantiate some fantastic javascript here for .some-class }); but have experienced no joy so far. Is there any way on either side (objective-c since I don't programmatically firing javascript post load, or javascript) to be notified when the element is in the DOM? Thanks, Josh

  Read the article

• Bi-directional view model syncing with "live" collections and properties (MVVM)

  - by Schneider

  I am getting my knickers in a twist recently about View Models (VM). Just like this guy I have come to the conclusion that the collections I need to expose on my VM typically contain a different type to the collections exposed on my business objects. Hence there must be a bi-directional mapping or transformation between these two types. (Just to complicate things, on my project this data is "Live" such that as soon as you change a property it gets transmitted to other computers) I can just about cope with that concept, using a framework like Truss, although I suspect there will be a nasty surprise somewhere within. Not only must objects be transformed but a synchronization between these two collections is required. (Just to complicate things I can think of cases where the VM collection might be a subset or union of business object collections, not simply a 1:1 synchronization). I can see how to do a one-way "live" sync, using a replicating ObservableCollection or something like CLINQ. The problem then becomes: What is the best way to create/delete items? Bi-directinal sync does not seem to be on the cards - I have found no such examples, and the only class that supports anything remotely like that is the ListCollectionView. Would bi-directional sync even be a sensible way to add back into the business object collection? All the samples I have seen never seem to tackle anything this "complex". So my question is: How do you solve this? Is there some technique to update the model collections from the VM? What is the best general approach to this?

  Read the article

• How Does MVC Handle Missing Data Requirements

  - by Don Bakke

  I'm teaching myself MVC concepts in hopes of applying them to a non-OO/procedural development environment. I am pretty sure I understand simple View - Request - Controller - Request - Model - Response - Controller - Response - View flow. What I am struggling with is understanding more complex scenarios. For instance, let's say I have a shopping cart form with a button for 'Calculate Shipping'. Normally a click on this button will follow the above flow. But what if there is missing data, like the zip code? Should the View verify this first and alert the user before making a 'Calculate Shipping' request? Or should the request be made and the Model returns a notification that critical data is missing? If the latter, does the Controller instruct the View to alert the user? What if I wanted to prompt the user for the missing zip code (perhaps in a popup input display) and then automatically request the 'Calculate Shipping' method again? I suppose this gets into the question of how smart a View ought to be. It seems that MVC has evolved due to richer UI and automation (such as with data-binding) and this muddies the water from a purist MVC perspective. Any thoughts are greatly appreciated.

  Read the article

< Previous Page | 145 146 147 148 149 150 151 152 153 154 155 156  | Next Page >