Search Results

Search found 42264 results on 1691 pages for 'template method pattern'.

Page 70/1691 | < Previous Page | 66 67 68 69 70 71 72 73 74 75 76 77  | Next Page >

• Writing a method to 'transform' an immutable object: how should I approach this?

  - by Prog

  (While this question has to do with a concrete coding dilemma, it's mostly about what's the best way to design a function.) I'm writing a method that should take two Color objects, and gradually transform the first Color into the second one, creating an animation. The method will be in a utility class. My problem is that Color is an immutable object. That means that I can't do color.setRGB or color.setBlue inside a loop in the method. What I can do, is instantiate a new Color and return it from the method. But then I won't be able to gradually change the color. So I thought of three possible solutions: 1- The client code includes the method call inside a loop. For example: int duration = 1500; // duration of the animation in milliseconds int steps = 20; // how many 'cycles' the animation will take for(int i=0; i<steps; i++) color = transformColor(color, targetColor, duration, steps); And the method would look like this: Color transformColor(Color original, Color target, int duration, int steps){ int redDiff = target.getRed() - original.getRed(); int redAddition = redDiff / steps; int newRed = original.getRed() + redAddition; // same for green and blue .. Thread.sleep(duration / STEPS); // exception handling omitted return new Color(newRed, newGreen, newBlue); } The disadvantage of this approach is that the client code has to "do part of the method's job" and include a for loop. The method doesn't do it's work entirely on it's own, which I don't like. 2- Make a mutable Color subclass with methods such as setRed, and pass objects of this class into transformColor. Then it could look something like this: void transformColor(MutableColor original, Color target, int duration){ final int STEPS = 20; int redDiff = target.getRed() - original.getRed(); int redAddition = redDiff / steps; int newRed = original.getRed() + redAddition; // same for green and blue .. for(int i=0; i<STEPS; i++){ original.setRed(original.getRed() + redAddition); // same for green and blue .. Thread.sleep(duration / STEPS); // exception handling omitted } } Then the calling code would usually look something like this: // The method will usually transform colors of JComponents JComponent someComponent = ... ; // setting the Color in JComponent to be a MutableColor Color mutableColor = new MutableColor(someComponent.getForeground()); someComponent.setForeground(mutableColor); // later, transforming the Color in the JComponent transformColor((MutableColor)someComponent.getForeground(), new Color(200,100,150), 2000); The disadvantage is - the need to create a new class MutableColor, and also the need to do casting. 3- Pass into the method the actual mutable object that holds the color. Then the method could do object.setColor or similar every iteration of the loop. Two disadvantages: A- Not so elegant. Passing in the object that holds the color just to transform the color feels unnatural. B- While most of the time this method will be used to transform colors inside JComponent objects, other kinds of objects may have colors too. So the method would need to be overloaded to receive other types, or receive Objects and have instanceof checks inside.. Not optimal. Right now I think I like solution #2 the most, than solution #1 and solution #3 the least. However I'd like to hear your opinions and suggestions regarding this.

  Read the article

• Another design-related C++ question

  - by Kotti

  Hi! I am trying to find some optimal solutions in C++ coding patterns, and this is one of my game engine - related questions. Take a look at the game object declaration (I removed almost everything, that has no connection with the question). // Abstract representation of a game object class Object : public Entity, IRenderable, ISerializable { // Object parameters // Other not really important stuff public: // @note Rendering template will never change while // the object 'lives' Object(RenderTemplate& render_template, /* params */) : /*...*/ { } private: // Object rendering template RenderTemplate render_template; public: /** * Default object render method * Draws rendering template data at (X, Y) with (Width, Height) dimensions * * @note If no appropriate rendering method overload is specified * for any derived class, this method is called * * @param Backend & b * @return void * @see */ virtual void Render(Backend& backend) const { // Render sprite from object's // rendering template structure backend.RenderFromTemplate( render_template, x, y, width, height ); } }; Here is also the IRenderable interface declaration: // Objects that can be rendered interface IRenderable { /** * Abstract method to render current object * * @param Backend & b * @return void * @see */ virtual void Render(Backend& b) const = 0; } and a sample of a real object that is derived from Object (with severe simplifications :) // Ball object class Ball : public Object { // Ball params public: virtual void Render(Backend& b) const { b.RenderEllipse(/*params*/); } }; What I wanted to get is the ability to have some sort of standard function, that would draw sprite for an object (this is Object::Render) if there is no appropriate overload. So, one can have objects without Render(...) method, and if you try to render them, this default sprite-rendering stuff is invoked. And, one can have specialized objects, that define their own way of being rendered. I think, this way of doing things is quite good, but what I can't figure out - is there any way to split the objects' "normal" methods (like Resize(...) or Rotate(...)) implementation from their rendering implementation? Because if everything is done the way described earlier, a common .cpp file, that implements any type of object would generally mix the Resize(...), etc methods implementation and this virtual Render(...) method and this seems to be a mess. I actually want to have rendering procedures for the objects in one place and their "logic implementation" - in another. Is there a way this can be done (maybe alternative pattern or trick or hint) or this is where all this polymorphic and virtual stuff sucks in terms of code placement?

  Read the article

• DotNetNuke Visual Studio Projects

  - by user326502

  I downloaded the DotNetNuke Visual Studio Installer, and the only project template I got was a Compiled Module. I've seen screen shots and examples where people had 'DNN Project' projects, and 'DNN Skin' projects. Did something go wrong with my installation? Where can I get a template for a DotNetNuke 5 Skin project?

  Read the article

• Compile error C++: could not deduce template argument for 'T'

  - by OneShot

  I'm trying to read binary data to load structs back into memory so I can edit them and save them back to the .dat file. readVector() attempts to read the file, and return the vectors that were serialized. But i'm getting this compile error when I try and run it. What am I doing wrong with my templates? ***** EDIT ************** Code: // Project 5.cpp : main project file. #include "stdafx.h" #include <iostream> #include <fstream> #include <string> #include <vector> #include <algorithm> using namespace System; using namespace std; #pragma hdrstop int checkCommand (string line); template<typename T> void writeVector(ofstream &out, const vector<T> &vec); template<typename T> vector<T> readVector(ifstream &in); struct InventoryItem { string Item; string Description; int Quantity; int wholesaleCost; int retailCost; int dateAdded; } ; int main(void) { cout << "Welcome to the Inventory Manager extreme! [Version 1.0]" << endl; ifstream in("data.dat"); vector<InventoryItem> structList; readVector<InventoryItem>( in ); while (1) { string line = ""; cout << endl; cout << "Commands: " << endl; cout << "1: Add a new record " << endl; cout << "2: Display a record " << endl; cout << "3: Edit a current record " << endl; cout << "4: Exit the program " << endl; cout << endl; cout << "Enter a command 1-4: "; getline(cin , line); int rValue = checkCommand(line); if (rValue == 1) { cout << "You've entered a invalid command! Try Again." << endl; } else if (rValue == 2){ cout << "Error calling command!" << endl; } else if (!rValue) { break; } } system("pause"); return 0; } int checkCommand (string line) { int intReturn = atoi(line.c_str()); int status = 3; switch (intReturn) { case 1: break; case 2: break; case 3: break; case 4: status = 0; break; default: status = 1; break; } return status; } template<typename T> void writeVector(ofstream &out, const vector<T> &vec) { out << vec.size(); for(vector<T>::const_iterator i = vec.begin(); i != vec.end(); i++) { out << *i; } } ostream& operator<<(std::ostream &strm, const InventoryItem &i) { return strm << i.Item << " (" << i.Description << ")"; } template<typename T> vector<T> readVector(ifstream &in) { size_t size; in >> size; vector<T> vec; vec.reserve(size); for(int i = 0; i < size; i++) { T tmp; in >> tmp; vec.push_back(tmp); } return vec; } Compiler errors: 1>------ Build started: Project: Project 5, Configuration: Debug Win32 ------ 1>Compiling... 1>Project 5.cpp 1>.\Project 5.cpp(124) : warning C4018: '<' : signed/unsigned mismatch 1> .\Project 5.cpp(40) : see reference to function template instantiation 'std::vector<_Ty> readVector<InventoryItem>(std::ifstream &)' being compiled 1> with 1> [ 1> _Ty=InventoryItem 1> ] 1>.\Project 5.cpp(127) : error C2679: binary '>>' : no operator found which takes a right-hand operand of type 'InventoryItem' (or there is no acceptable conversion) 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(1144): could be 'std::basic_istream<_Elem,_Traits> &std::operator >><std::char_traits<char>>(std::basic_istream<_Elem,_Traits> &,signed char *)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(1146): or 'std::basic_istream<_Elem,_Traits> &std::operator >><std::char_traits<char>>(std::basic_istream<_Elem,_Traits> &,signed char &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(1148): or 'std::basic_istream<_Elem,_Traits> &std::operator >><std::char_traits<char>>(std::basic_istream<_Elem,_Traits> &,unsigned char *)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(1150): or 'std::basic_istream<_Elem,_Traits> &std::operator >><std::char_traits<char>>(std::basic_istream<_Elem,_Traits> &,unsigned char &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(155): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(std::basic_istream<_Elem,_Traits> &(__cdecl *)(std::basic_istream<_Elem,_Traits> &))' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(161): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(std::basic_ios<_Elem,_Traits> &(__cdecl *)(std::basic_ios<_Elem,_Traits> &))' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(168): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(std::ios_base &(__cdecl *)(std::ios_base &))' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(175): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(std::_Bool &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(194): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(short &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(228): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(unsigned short &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(247): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(int &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(273): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(unsigned int &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(291): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(long &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(309): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(__w64 unsigned long &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(329): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(__int64 &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(348): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(unsigned __int64 &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(367): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(float &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(386): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(double &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(404): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(long double &)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(422): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(void *&)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\include\istream(441): or 'std::basic_istream<_Elem,_Traits> &std::basic_istream<_Elem,_Traits>::operator >>(std::basic_streambuf<_Elem,_Traits> *)' 1> with 1> [ 1> _Elem=char, 1> _Traits=std::char_traits<char> 1> ] 1> while trying to match the argument list '(std::ifstream, InventoryItem)' 1>Build log was saved at "file://c:\Users\Owner\Documents\Visual Studio 2008\Projects\Project 5\Project 5\Debug\BuildLog.htm" 1>Project 5 - 1 error(s), 1 warning(s) ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ========== Oh my god...I fixed that error I think and now I got another one. Will you PLEASE just help me on this one too! What the heck does this mean ??

  Read the article

• About variadic templates

  - by chedi

  Hi, I'm currently experiencing with the new c++0x variadic templates, and it's quit fun, Although I have a question about the process of member instanciation. in this example, I'm trying to emulate the strongly typed enum with the possibility of choose a random valid strong enum (this is used for unit testing). #include<vector> #include<iostream> using namespace std; template<unsigned... values> struct sp_enum; /* this is the solution I found, declaring a globar var vector<unsigned> _data; and it work just fine */ template<> struct sp_enum<>{ static const unsigned _count = 0; static vector<unsigned> _data; }; vector<unsigned> sp_enum<>::_data; template<unsigned T, unsigned... values> struct sp_enum<T, values...> : private sp_enum<values...>{ static const unsigned _count = sp_enum<values...>::_count+1; static vector<unsigned> _data; sp_enum( ) : sp_enum<values...>(values...) {_data.push_back(T);} sp_enum(unsigned v ) {_data.push_back(v);} sp_enum(unsigned v, unsigned...) : sp_enum<values...>(values...) {_data.push_back(v);} }; template<unsigned T, unsigned... values> vector<unsigned> sp_enum<T, values...>::_data; int main(){ enum class t:unsigned{Default = 5, t1, t2}; sp_enum<t::Default, t::t1, t::t2> test; cout <<test._count << endl << test._data.size() << endl; for(auto i= test._data.rbegin();i != test._data.rend();++i){cout<< *i<< ":";} } the result I'm getting with this code is : 3 1 5: can someone point me what I'm messing here ??? Ps: using gcc 4.4.3

  Read the article

• ASP.NET - Nested Custom Templates

  - by Echilon

  I'm thinking about converting a few usercontrols to use templates instead. One of these is my own UC which contains some controls, one of which is a repeater. Is it possible to specifcy a template for the second level usercontrol from the template for the first (which would be on the page)?

  Read the article

• Why don't all XSLT templates get executed at once?

  - by Matt W

  Refer to: http://stackoverflow.com/questions/1613454/retrieving-one-element-and-filter-by-another In the above linked posting, I don't understand why the two template blocks don't get executed upon in the incoming XML at the same time. As far I can can see, the XSL risks the second template executing for every Document element whether it is called with apply-templates or not. Could someone explain this to my stifled brain, please? Thanks, Matt.

  Read the article

• How do I make nested regroups in Django?

  - by Marcio Cruz

  I've got the following situation in this system: Each category of products has many subcategories, and each subcategory has many products under it. I'm trying to make a product searh, which returns a list, and in my template, I show an overview of the results, like this: Cellphones Dumbphones (2 results) Smartphones (3 results) Monitors CRT (1 result) LCD (3 results) I'm my template I have only the list of products. I've tryed many combinations of nested regroups, without success. Any ideas?

  Read the article

• Question about factory classes

  - by devoured elysium

  Currently I have created a ABCFactory class that has a single method creating ABC objects. Now that I think of it, maybe instead of having a factory, I could just make a static method in my ABC Method. What are the pro's and con's on making this change? Will it not lead to the same? I don't foresee having other classes inherit ABC, but one never knows! Thanks

  Read the article

• Amazon WebStore hide/disable/remove

  - by Paul

  Hey guys, I'm new to template editting. I'm trying to remove a table from the Amazon's WebStore template so i can start designing my own. Anyone out there know how I can go about hiding/disabling/removing/bypassing it?

  Read the article

• Is is possible to create a factory class in PHP?

  - by user198729

  Like the BeanFactory in java: In the much more common case where the BeanFactory itself directly creates the bean by calling its constructor (equivalent to Java code calling new), the class attribute specifies the class of the bean to be constructed. In the less common case where the BeanFactory calls a static, so-called factory method on a class to create the bean, the class attribute specifies the actual class containing the static factory method. Note:it's not the factory method

  Read the article

• C++: get const or non-const reference type from trait

  - by maciekp

  I am writing a functor F which takes function of type void (*func)(T) and func's argument arg. Then functor F calls func with arg. I would like F not to copy arg, just to pass it as reference. But then I cannot simply write "void F(void (*func)(T), T&)" because T could be a reference. So I am trying to write a trait, which allows to get proper reference type of T: T -> T& T& -> T& const T -> const T& const T& -> const T& I come up with something like this: template<typename T> struct type_op { typedef T& valid_ref_type; }; template<typename T> struct type_op<T&> { typedef typename type_op<T>::valid_ref_type valid_ref_type; }; template<typename T> struct type_op<const T> { typedef const T& valid_ref_type; }; template<typename T> struct type_op<const T&> { typedef const T& valid_ref_type; }; Which doesn't work for example for void a(int x) { std::cout << x << std::endl; } F(&a, 7); Giving error: invalid initialization of non-const reference of type ‘int&’ from a temporary of type ‘int’ in passing argument 2 of ‘void f(void (*)(T), typename type_op::valid_ref_type) [with T = int]’ How to get this trait to work?

  Read the article

• HibernateTemplate alwaysUseNewSession

  - by DD

  Hi, I had a problem where I was using the hibernate template to do most of my DB work but I had a part of the system that directly accessed the session to do batch persisting. I noticed that the hibernate template session was old and would be storing cached values which didnt take into account the objects save with the session directly. What are the drawbacks of using alwaysUseNewSession? This fixes the problem as I always get up-to-date objects. Thanks.

  Read the article

• Which CMS to use?

  - by Hastings

  I need to create a web (or non-web) system where a user can create a template layout with tags and placeholders for elements. They could then add new pages to this template. My system would need to pick up any elements that have changed and create an XML of the tagged content. I was just wondering what would be the best CMS or any other software I could use to implement this?

  Read the article

• Return template as string - Django

  - by Ninefingers

  Hi All, I'm still not sure this is the correct way to go about this, maybe not, but I'll ask anyway. I'd like to re-write wordpress (justification: because I can) albeit more simply myself in Django and I'm looking to be able to configure elements in different ways on the page. So for example I might have: Blog models A site update message model A latest comments model. Now, for each page on the site I want the user to be able to choose the order of and any items that go on it. In my thought process, this would work something like: class Page(models.Model) Slug = models.CharField(max_length=100) class PageItem(models.Model) Page = models.ForeignKey(Page) ItemType = models.CharField(max_length=100) InstanceNum = models.IntegerField() # all models have primary keys. Then, ideally, my template would loop through all the PageItems in a page which is easy enough to do. But what if my page item is a site update as opposed to a blog post? Basically, I am thinking I'd like to pull different item types back in different orders and display them using the appropriate templates. Now, I thought one way to do this would be to, in views.py, to loop through all of the objects and call the appropriate view function, return a bit of html as a string and then pipe that into the resultant template. My question is - is this the best way to go about doing things? If so, how do I do it? If not, which way should I be going? I'm pretty new to Django so I'm still learning what it can and can't do, so please bear with me. I've checked SO for dupes and don't think this has been asked before...

  Read the article

• Changing or accessing a control in a Silverlight Data Form Edit Template

  - by Aim Kai

  I came across an interesting issue today when playing around with the Silverlight Data Form control. I wanted to change the visibility of a particular control inside the bound edit template.. see xaml below. <df:DataForm x:Name="NoteFormEdit" ItemsSource="{Binding Mode=OneWay}" AutoGenerateFields="True" AutoEdit="True" AutoCommit="False" CommitButtonContent="Save" CancelButtonContent="Cancel" CommandButtonsVisibility="Commit" LabelPosition="Top" ScrollViewer.VerticalScrollBarVisibility="Disabled" EditEnded="NoteForm_EditEnded"> <df:DataForm.EditTemplate> <DataTemplate> <StackPanel> <df:DataField> <TextBox Text="{Binding Title, Mode=TwoWay}"/> </df:DataField> <df:DataField> <TextBox Text="{Binding Description, Mode=TwoWay}" AcceptsReturn="True" HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto" Height="" TextWrapping="Wrap" SizeChanged="TextBox_SizeChanged"/> </df:DataField> <df:DataField> <TextBlock Text="{Binding Username}" x:Name="tbUsername"/> </df:DataField> <df:DataField> <TextBlock Text="{Binding DateCreated, Converter={StaticResource DateConverter}}" x:Name="tbDateCreated"/> </df:DataField> </StackPanel> </DataTemplate> </df:DataForm.EditTemplate> </df:DataForm> I wanted to depending on how the container of this data form was accessed to disable or hide the last two data fields. I did a work around which had two data forms but this is a bit excessive! Does anyone know how to access these controls inside the edit template?

  Read the article

• MVC - Cocoa interface - Cocoa Design pattern book

  - by Idan

  So I started reading this book: http://www.amazon.com/Cocoa-Design-Patterns-Erik-Buck/dp/0321535022 On chapter 2 it explains about the MVC design pattern and gives and example which I need some clarification to. The simple example shows a view with the following fields: hourlyRate, WorkHours, Standarthours , salary. The example is devided into 3 parts : View - contains some text fiels and a table (the table contains a list of employees' data). Controller - comprised of NSArrayController class (contains an array of MyEmployee) Model - MyEmployee class which describes an employee. MyEmployee class has one method which return the salary according to the calculation logic, and attributes in accordance with the view UI controls. MyEmployee inherits from NSManagedObject. Few things i'm not sure of : 1. Inside the MyEmplpyee class implemenation file, the calculation method gets the class attributes using sentence like " [[self valueForKey:@"hourlyRate"] floatValue];" Howevern, inside the header there is no data member named hourlyRate or any of the view fields. I'm not quite sure how does it work, and how it gets the value from the right view field. (does it have to be the same name as the field name in the view). maybe the conncetion is made somehow using the Interface builder and was not shown in the book ? and more important: 2. how does it seperate the view from the model ? let's say ,as the book implies might happen, I decide one day to remove one of the fields in the view. as far as I understand, that means changing the way the salary method works in MyEmplpyee (cause we have one field less) , and removing one attribute from the same calss. So how is that separate the View from the Model if changing one reflect on the other ? I guess I get something wrong... Any comments ? Thanks

  Read the article

• WPF Infinite loop in references found while processing the Template

  - by Ryan

  I am pretty new to WPF and am getting this error after my mouse is over my custom listbox item. Error: Infinite loop in references found while processing the Template for an element named '' of type 'System.Windows.Controls.TextBox'. <Window.Resources> <ControlTemplate x:Key="MouseOverFocusTemplate" > <Grid> <Grid.RowDefinitions> <RowDefinition Height="55*" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <TextBox Width="290" TextAlignment="Left" VerticalContentAlignment="Center" BorderThickness="0" BorderBrush="Transparent" Foreground="#FF6FB8FD" FontSize="24" TextWrapping="Wrap" Text="{Binding .}" Grid.Column="1" Grid.Row="1" MinHeight="55" Cursor="Hand" IsReadOnly="True" FontFamily="Arial" > <TextBox.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <GradientStop Color="#FF013B73" Offset="0.501"/> <GradientStop Color="#FF091F34"/> <GradientStop Color="#FF014A8F" Offset="0.5"/> <GradientStop Color="#FF003363" Offset="1"/> </LinearGradientBrush> </TextBox.Background> </TextBox> </Grid> </ControlTemplate> <Style x:Key="MouseOverFocusStyle" TargetType="{x:Type TextBox}"> <Setter Property="Template" Value="{StaticResource MouseOverFocusTemplate}"/> </Style> <ControlTemplate x:Key="LostFocusTemplate" > <Grid> <Grid.RowDefinitions> <RowDefinition Height="55*" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <TextBox Width="290" TextAlignment="Left" VerticalContentAlignment="Center" BorderThickness="0" BorderBrush="Transparent" Foreground="#FF6FB8FD" FontSize="24" TextWrapping="Wrap" Text="{Binding .}" Grid.Column="1" Grid.Row="1" MinHeight="55" Cursor="Hand" IsReadOnly="True" FontFamily="Arial" > <TextBox.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <LinearGradientBrush.RelativeTransform> <TransformGroup> <ScaleTransform CenterX="0.5" CenterY="0.5"/> <SkewTransform CenterX="0.5" CenterY="0.5"/> <RotateTransform CenterX="0.5" CenterY="0.5"/> <TranslateTransform/> </TransformGroup> </LinearGradientBrush.RelativeTransform> <GradientStop Color="#FF091F34" Offset="1"/> <GradientStop Color="#FF002F5C" Offset="0.4"/> </LinearGradientBrush> </TextBox.Background> </TextBox> </Grid> </ControlTemplate> <Style x:Key="LostFocusStyle" TargetType="{x:Type TextBox}"> <Setter Property="Template" Value="{StaticResource LostFocusTemplate}"/> </Style> <ControlTemplate x:Key="GotFocusTemplate" > <Grid> <Grid.RowDefinitions> <RowDefinition Height="55*" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <TextBox Width="290" TextAlignment="Left" VerticalContentAlignment="Center" BorderThickness="0" BorderBrush="Transparent" Foreground="#FFE38E27" FontSize="24" TextWrapping="Wrap" Text="{Binding .}" Grid.Column="1" Grid.Row="1" MinHeight="55" Cursor="Hand" IsReadOnly="True" FontFamily="Arial" > <TextBox.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <GradientStop Color="Black" Offset="0.501"/> <GradientStop Color="#FF091F34"/> <GradientStop Color="#FF002F5C" Offset="0.5"/> </LinearGradientBrush> </TextBox.Background> </TextBox> </Grid> </ControlTemplate> <Style x:Key="GotFocusStyle" TargetType="{x:Type TextBox}"> <Setter Property="Template" Value="{StaticResource GotFocusTemplate}"/> </Style> <Style TargetType="ListBoxItem"> <EventSetter Event="GotFocus" Handler="ListItem_GotFocus"></EventSetter> <EventSetter Event="LostFocus" Handler="ListItem_LostFocus"></EventSetter> <EventSetter Event="Mouse.MouseMove" Handler="ListItem_MouseOver"></EventSetter> </Style> <DataTemplate DataType="{x:Type TextBlock}"> </DataTemplate> <DataTemplate x:Key="CustomListData" DataType="{x:Type ListBoxItem}"> <Border BorderBrush="Black" BorderThickness="1" Margin="-2,0,0,-1"> <Grid> <Grid.RowDefinitions> <RowDefinition Height="55*" /> </Grid.RowDefinitions> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto" /> <ColumnDefinition Width="*" /> </Grid.ColumnDefinitions> <Grid.RenderTransform> <TransformGroup> <ScaleTransform ScaleX="1" ScaleY="1"/> <SkewTransform AngleX="0" AngleY="0"/> <RotateTransform Angle="0"/> <TranslateTransform X="0" Y="0"/> </TransformGroup> </Grid.RenderTransform> <!--<ScrollViewer x:Name="PART_ContentHost" />--> <TextBox Width="290" TextAlignment="Left" VerticalContentAlignment="Center" BorderThickness="0" BorderBrush="Transparent" Foreground="#FF6FB8FD" FontSize="24" FocusVisualStyle="{StaticResource GotFocusStyle}" TextWrapping="Wrap" Text="{Binding .}" Grid.Column="1" Grid.Row="1" MinHeight="55" Cursor="Hand" IsReadOnly="True" FontFamily="Arial" > <TextBox.Background> <LinearGradientBrush EndPoint="0.5,1" StartPoint="0.5,0"> <LinearGradientBrush.RelativeTransform> <TransformGroup> <ScaleTransform CenterX="0.5" CenterY="0.5"/> <SkewTransform CenterX="0.5" CenterY="0.5"/> <RotateTransform CenterX="0.5" CenterY="0.5"/> <TranslateTransform/> </TransformGroup> </LinearGradientBrush.RelativeTransform> <GradientStop Color="#FF091F34" Offset="1"/> <GradientStop Color="#FF002F5C" Offset="0.4"/> </LinearGradientBrush> </TextBox.Background> </TextBox> </Grid> </Border> </DataTemplate> <Style TargetType="{x:Type ListBox}"> <Setter Property="ItemTemplate" Value="{StaticResource CustomListData }" /> <Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Disabled" /> </Style> </Window.Resources> <Window.DataContext> <ObjectDataProvider ObjectType="{x:Type local:ImageLoader}" MethodName="LoadImages" /> </Window.DataContext> <ListBox ItemsSource="{Binding}" Width="320" Background="#FF021422" BorderBrush="#FF1C4B79"> <ListBox.Resources> <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}">Transparent</SolidColorBrush> </ListBox.Resources> </ListBox> The code behind for the mouse over event is as follows private void ListItem_MouseOver(object sender, RoutedEventArgs e) { e.Handled = true; FrameworkElement element = e.OriginalSource as FrameworkElement; if (element != null) { while (VisualTreeHelper.GetParent(element) != null) { element = VisualTreeHelper.GetParent(element) as FrameworkElement; TextBox item = element as TextBox; if (item != null) { item.Style = (Style)item.FindResource("MouseOverFocusStyle"); return; } } } } What am I missing? Is there an easier way to do this ? Thanks in advance Ryan

  Read the article

• Resharper Live Template Macro that changes variable name upon exit

  - by Luhmann

  I would like to create a Resharper Live Template that changes all spaces to underscores ind my "fact" Live template variable $testname$: <Fact()> _ Public Sub $testnames$() ' Arrange $END$ ' Act ' Assert End Sub I have this: [Macro("applyRegex", ShortDescription = "Run on {#0:variable}", LongDescription = "")] class ApplyRegexMacro : IMacro { public string EvaluateQuickResult(IHotspotContext context, IList<string> arguments) { return Regex.Replace(arguments[0], " ", "_", RegexOptions.IgnoreCase); } public HotspotItems GetLookupItems(IHotspotContext context, IList<string> arguments) { return null; } public string GetPlaceholder() { return "placeholder"; } public bool HandleExpansion(IHotspotContext context, IList<string> arguments) { return false; } public ParameterInfo[] Parameters { get { return new[] { new ParameterInfo(ParameterType.String), new ParameterInfo(ParameterType.String), new ParameterInfo(ParameterType.VariableReference) }; } } } But this only runs when i press tab. I want the macro to run after I tab out of $testname$. I want to be able to just write the test name in a single line of text with spaces, and then the Macro turns all the spaces into underscores. Is this possible?

  Read the article

• Django: Named URLs / Same Template, Different Named URL

  - by TheLizardKing

  I have a webapp that lists all of my artists, albums and songs when the appropriate link is clicked. I make extensive use of generic views (object_list/detail) and named urls but I am coming across an annoyance. I have three templates that pretty much output the exact same html that look just like this: {% extends "base.html" %} {% block content %} <div id="content"> <ul id="starts-with"> {% for starts_with in starts_with_list %} <li><a href="{% url song_list_x starts_with %}">{{ starts_with|upper }}</a></li> {% endfor %} </ul> <ul> {% for song in songs_list %} <li>{{ song.title }}</li> {% endfor %} </ul> </div> {% endblock content %} My artist and album template look pretty much the same and I'd like to combine the three template's into one. The fact that my variables start with song can easily be changed to the default obj. It's my <ul id="starts-with"> named url I don't know how to correct. Obviously I want it to link to a specific album/artist/song using the named urls in my urls.py but I don't know how to make it context aware. Any suggestions? urlpatterns = patterns('tlkmusic.apps.tlkmusic_base.views', # (r'^$', index), url(r'^artists/$', artist_list, name='artist_list'), url(r'^artists/(?P<starts_with>\w)/$', artist_list, name='artist_list_x'), url(r'^artist/(?P<artist_id>\d+)/$', artist_detail, name='artist_detail'), url(r'^albums/$', album_list, name='album_list'), url(r'^albums/(?P<starts_with>\w)/$', album_list, name='album_list_x'), url(r'^songs/$', song_list, name='song_list'), url(r'^songs/(?P<starts_with>\w)/$', song_list, name='song_list_x'), )

  Read the article

• algorithm || method to write prog

  - by fatai

  I am one of the computer science student. My wonder is everyone solve problem with different or same method, but actually I dont know whether they use method or I dont know whether there are such common method to approach problem. All teacher give us problem which in simple form sometimes, but they dont introduce any approach or method(s) so that we can first choose method then apply that one to problem , afterward find solution then write code. I have found one method when I failed the course, More accurately, When I counter problem in language , I will get more paper and then ; first, input/ output step ; my prog will take this / these there argument(s) and return namely X , ex : in c, input length is not known and at same type , so I must use pointer desired output is in form of package , so use structure second, execution part ; in that step , I am writing all step which are goes to final output ex : in python ; 1.) [ + , [- , 4 , [ * , 1 , 2 ]], 5] 2.) [ + , [- , 4 , 2 ],5 ] 3.) [ + , 2 , 5] 4.) 7 ==> return 7 third, I will write test code ex : in c++ input : append 3 4 5 6 vector_x remove 0 1 desired output vector_x holds : 5 6 But now, I wonder other method ; used to construct class :::: for c++ , python, java used to communicate classes / computers used for solving embedded system problem ::::: for c Why I wonder , because I learn if you dont costruct algorithm on paper, you may achieve your goal. Like no money no lunch , I can say no algorithm no prog therefore , feel free when you write your own method , a way which is introduced by someone else but you are using and you find it is so efficient

  Read the article

• Default template parameters with forward declaration

  - by Seth Johnson

  Is it possible to forward declare a class that uses default arguments without specifying or knowing those arguments? For example, I would like to declare a boost::ptr_list< TYPE > in a Traits class without dragging the entire Boost library into every file that includes the traits. I would like to declare namespace boost { template<class T> class ptr_list< T >; }, but that doesn't work because it doesn't exactly match the true class declaration: template < class T, class CloneAllocator = heap_clone_allocator, class Allocator = std::allocator<void*> > class ptr_list { ... }; Are my options only to live with it or to specify boost::ptr_list< TYPE, boost::heap_clone_allocator, std::allocator<void*> in my traits class? (If I use the latter, I'll also have to forward declare boost::heap_clone_allocator and include <memory>, I suppose.) I've looked through Stroustrup's book, SO, and the rest of the internet and haven't found a solution. Usually people are concerned about not including STL, and the solution is "just include the STL headers." However, Boost is a much more massive and compiler-intensive library, so I'd prefer to leave it out unless I absolutely have to.

  Read the article

• Binder and variadic template ends up in a segmentation fault

  - by phlipsy

  I wrote the following program #include <iostream> template<typename C, typename Res, typename... Args> class bind_class_t { private: Res (C::*f)(Args...); C *c; public: bind_class_t(Res (C::*f)(Args...), C* c) : f(f), c(c) { } Res operator() (Args... args) { return (c->*f)(args...); } }; template<typename C, typename Res, typename... Args> bind_class_t<C, Res, Args...> bind_class(Res (C::*f)(Args...), C* c) { return bind_class<C, Res, Args...>(f, c); } class test { public: int add(int x, int y) { return x + y; } }; int main() { test t; // bind_class_t<test, int, int, int> b(&test::add, &t); bind_class_t<test, int, int, int> b = bind_class(&test::add, &t); std::cout << b(1, 2) << std::endl; return 0; } compiled it with gcc 4.3.3 and got a segmentation fault. After spending some time with gdb and this program it seems to me that the addresses of the function and the class are mixed up and a call of the data address of the class isn't allowed. Moreover if I use the commented line instead everything works fine. Can anyone else reproduce this behavior and/or explain me what's going wrong here?

  Read the article

• Emulating Dynamic Dispatch in C++ based on Template Parameters

  - by Jon Purdy

  This is heavily simplified for the sake of the question. Say I have a hierarchy: struct Base { virtual int precision() const = 0; }; template<int Precision> struct Derived : public Base { typedef Traits<Precision>::Type Type; Derived(Type data) : value(data) {} virtual int precision() const { return Precision; } Type value; }; I want a function like: Base* function(const Base& a, const Base& b); Where the specific type of the result of the function is the same type as whichever of first and second has the greater Precision; something like the following pseudocode: template<class T> T* operation(const T& a, const T& b) { return new T(a.value + b.value); } Base* function(const Base& a, const Base& b) { if (a.precision() > b.precision()) return operation((A&)a, A(b.value)); else if (a.precision() < b.precision()) return operation(B(a.value), (B&)b); else return operation((A&)a, (A&)b); } Where A and B are the specific types of a and b, respectively. I want f to operate independently of how many instantiations of Derived there are. I'd like to avoid a massive table of typeid() comparisons, though RTTI is fine in answers. Any ideas?

  Read the article

• Template operator linker error

  - by Dani

  I have a linker error I've reduced to a simple example. The build output is: debug/main.o: In function main': C:\Users\Dani\Documents\Projects\Test1/main.cpp:5: undefined reference tolog& log::operator<< (char const (&) [6])' collect2: ld returned 1 exit status It looks like the linker ignores the definition in log.cpp. I also cant put the definition in log.h because I include the file alot of times and it complains about redefinitions. main.cpp: #include "log.h" int main() { log() << "hello"; return 0; } log.h: #ifndef LOG_H #define LOG_H class log { public: log(); template<typename T> log &operator <<(T &t); }; #endif // LOG_H log.cpp: #include "log.h" #include <iostream> log::log() { } template<typename T> log &log::operator <<(T &t) { std::cout << t << std::endl; return *this; }

  Read the article

< Previous Page | 66 67 68 69 70 71 72 73 74 75 76 77  | Next Page >