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Aescleal wrote:
I'd get rid of the private member functions and use a PIMPL [1] for your key generator class. It clears a lot of stuff out of the header file and makes that a bit easier to use. If you can end up with something minimal it doesn't help people using your code. Perhaps something like:
class key_generator_data;
class key_generator
{
public:
key_generator( const unsigned key_size );
key_pair create_new_key() const;
private:
std::unique_ptr<key_generator_data> data_;
};
And that's it with key_pair, public_key and private_key being classes. That's an interesting concept, PimpL.. I'll try implementing it. But why having so many classes for keys(key_pair, public_key and private_key) instead of a single key class will be better?
Aescleal wrote: The only other thing I'd comment on would be what your encryption and decryption functions are called and the parameters they take. Perhaps consider having a stream interface as well?
bool encrypt( std::istream &plain_text, std::ostream &cypher_text, const std::string &n, const std::string &e );
bool decrypt( std::istream &cypher_text, std::ostream &plain_text, const std::string &n, const std::string &d );
Perhaps have better naming for the public and private keys as well.
I know that you don't generally encode much with RSA but stream interfaces make it a lot easier to encrypt and decrypt stuff. You can test stuff by entering plain text at the console, reading it from a file or even over a socket without the caller having to buffer anything. Ahh that's another great idea.. it will surely come handy. Also, I realized that encryption and decryption are exactly similar(except the parameters ofcourse), a single function will suffice
bool crypt( std::istream &in, std::ostream &out, const std::string &n, const std::string &e );
Aescleal wrote: One final point... If you intend doing anything else it might be worth making an abstract base encryptor class and implementing your code in terms of that. Then if you ever decide to use a different asymmetric encryption algorithm or want to unit test client code you can just in a replacement. Base class encryptor? Can you please throw some more light on this?
Thanks Ash
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A single key class would work as well. I've usually used one for the private key and one for the public key but thats probably just a matter of taste.
The abstract base class thing...
What I was suggesting was defining an interface class:
class encryptor
{
public:
virtual bool encrypt( ... ) = 0;
virtual bool decrypt( ... ) = 0;
};
and you'll have an implementation like:
class RSA_encryptor : public encryptor
{
public:
virtual bool encrypt( ... );
virtual bool decrypt( ... );
};
then when you write your client code it uses the encryptor interace, creating an RSA_encryptor to do your stuff. It's be something like:
void do_something( encryptor *enc )
{
}
int main()
{
key k(...);
RSA_encryptor rsa( &key );
do_something( &rsa );
}
This means that do_something can be unit tested by chucking in a mock encryptor and if you ever need to change algorithm you can just change the top level declaration and it all works swimmingly.
Hope that helps,
Cheers,
Ash
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Wow.. I understand now and can see the benefits of using that too. I often miss using this OOP features. Can you please suggest me some good book for learning the usage of OOP features in C++(advanced C++)?
Thanks again Ash
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I don't know of any C++ text that does a good job at OO design.
I'd have a look at "Design Patterns: Elements of Reusable Object-Oriented Software" by Gamma, Helm, Johnson and Vlissides. It's nearly 20 years old but goes over some common design templates (for the want of a better word) that you can integrate into your code. The C++ implementations are complete rubbish but the underlying principles are well worth a look. Incidentally when you read articles/other books/forums about OO design and implementation this book is called the GoF (Gang Of Four).
Other more advanced books that are worth a read are "Exceptional C++" by Herb Sutter - it's got a lot about how to implement classes to break dependencies but less about how to actually do OO stuff. Still worth a read.
"Agile Software Development, Principles, Patterns, and Practices" by Robert C. Martin. It's got a rehash of some of the GoF patterns which is more accessible. It's mostly about how to develop software but there's a fair amount of material on OO desing and programming. Unfortunately the examples are in Java but the text surrounding it is well worth a read.
If you have access to a good public or academic library then it might be worth getting a loan off them first before going bananas and spending loads of cash.
Ash
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Hello Friends
I am creating a dialog based Application in which I am creating several Tabs.I am adding seven button to this Dialog also.
Now,I want to set the some color on Button. And,On Tab change ,I want to change the colors of button too.
Any Ideas?
Thanks & regards
Yogesh
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By: I want to set the some color on Button
Do you mean set some bitmap and change it to indicate button state or change the color of the whole button?
JohnCz
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I set the Button WS_DISABLED and i want to change the Whole Color Of Button.
Yogesh
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yogeshs wrote: Now,I want to set the some color on Button. Are you handling the WM_CTLCOLORBTN message?
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"Show me a community that obeys the Ten Commandments and I'll show you a less crowded prison system." - Anonymous
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No, I am not handling this Message .But i tried to inherit Class from CButton and tried to set color.
But no use.
And i want to change the color at runtime also.So,for that Do I need to Override Drawitem? What its Actual Working ?
Some Ideas ??
Regards
Yogesh
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yogeshs wrote: No, I am not handling this Message .But i tried to inherit Class from CButton and tried to set color. But no use.
I think you have to use ON_NOTIFY_REFLECT() in the button's message map, or ON_NOTIFY() in the parent (i.e., dialog).
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"Show me a community that obeys the Ten Commandments and I'll show you a less crowded prison system." - Anonymous
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Perhaps this[^] may be helpful.
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WM_CTLCOLORBTN does not work for buttons, since it draws face and borders.
If you are using VS 2008 with feature pack or with SP1 use CMFCButton class. To set button face color, call SetFaceColor member. You have to set m_bTransparent to FALSE anf disable teaming by calling EnableWindowsTheming member and passing FALSE as parameter.
If you are using earlier version of VS you will have to use owner drawn button and draw button yourself.
Another alternative would be to set bitmap for the button with BS_BITMAP style; do not use CBitmapButton.
JohnCz
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JohnCz wrote: WM_CTLCOLORBTN does not work for buttons, since it draws face and borders.
So MSDN's "The parent window can change the button's text and background colors" statement is wrong?
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"Show me a community that obeys the Ten Commandments and I'll show you a less crowded prison system." - Anonymous
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This is out of context. Can you send me a link to the full statement?
JohnCz
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MSDN states also (below the line you have quoted):
"By default, the DefWindowProc function selects the default system colors for the button. Buttons with the BS_PUSHBUTTON, BS_DEFPUSHBUTTON, or BS_PUSHLIKE styles do not use the returned brush. Buttons with these styles are always drawn with the default system colors. Drawing push buttons requires several different brushes-face, highlight, and shadow-but the WM_CTLCOLORBTN message allows only one brush to be returned. To provide a custom appearance for push buttons, use an owner-drawn button. For more information, see Creating Owner-Drawn Controls."
This is also incorrect, as you can see from the sample code at the bottom.
Radio and check boxes use static background color. If you change styles to "push like" color of the face will also not change. As you can see parent window is not able to change button’s face color of the pushbutton.
In conclusion, MSDN is incorrect (not the first time).
JohnCz
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Hello
I used CButon class to create button and then i override the DrawItem in Window class.
But its not Coming on Drawitem,where I am updating the color of Button.
Thanks
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Hey Friends
i got something That is working but need some help from you.
Here is the way.I created a new class CColorButton inherit from CButton.
And override functions paint and draw to set color.
But when I am attaching my ButtonId to object of CCOlorbutton,it is giving some assertion.
I am trying like this
CColorbutton* pBtn = new CColorButton();
pBtn->Attach(GetDlgItemId( IDC_BUTTON_ID + ndx )->GetSafeHwnd());
Regards
Yogesh
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yogeshs,
I think you are confusing two things: Windows window with MFC object that is not a window.
MFC object encapsulates window handle and only after window handle is valid, such an object represent Windows window. There are three ways to make MFC object alive (assign a valid handle):
Calling member function Create for a given class
Calling Attach
Subclassing window
Only calling Create and Subclassing will allow MFC object handling messages of the attached window.
Calling Attach will not allow process any messages processing, since window procedure has not been replaced by the object’s window procedure.
You should post a snippet that shows a function where it assert. Your code snippet does not make much sense since the meaning of the GetDlgItemId is unknown. Regardless, it looks like you are trying to attach an object that is already alive, meaning Windows window has MFC object attached to it. MFC code does it for you.
Please answer one question that I have already asked: What version of Visual Studio you are using? Maybe taking it from here will be more beneficial for you.
JohnCz
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I am using Vs2008 professional.
Thanks For Your Reply.
Trying To Understand.
Thanks
Yogesh
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OK, that is good so far. If you have SP1 installed, why not to follow my previous advice (from my earlier response):
If you are using VS 2008 with feature pack or with SP1 use CMFCButton class. To set button face color, call SetFaceColor member. You have to set m_bTransparent to FALSE anf disable teaming by calling EnableWindowsTheming member and passing FALSE as parameter.
This is much easier than reinventing a wheel.
JohnCz
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Hello JohnCz
I tried to use CMFCButton but there is no class in VS2008 prof.
Do i need to link up something?
Thanks Again.
Regards
Yogesh
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yogeshs wrote: I tried to use CMFCButton... How? When you added a button to the dialog template and went to assign a variable to it, the Add Member Variable Wizard defaulted to CButton . All you need to do is change that to CMFCButton . The appropriate header file (i.e., afxbutton.h ) would have been added automatically, if it was not already included.
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"Show me a community that obeys the Ten Commandments and I'll show you a less crowded prison system." - Anonymous
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Hi yogeshs,
You have to learn how to be patient and read all answers and documentation without skipping some parts.
I have already mentioned twice:
If you are using VS 2008 with feature pack or with SP1 use CMFCButton class.
You need Visual Studio SP1 installed.
Web installer[^]
ISO image[^]
Than you can subclass button using CMFCCustButton.
Subclassing is easy if you use wizard:
Right click on the button in the resource editor and choose Add Variable.
The only option you have is CButton, so select it.
After wizard closes, open dialog’s header file and change CButton to CMFCMenuButton.
JohnCz
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yogeshs wrote: CColorbutton* pBtn = new CColorButton(); pBtn->Attach(GetDlgItemId( IDC_BUTTON_ID + ndx )->GetSafeHwnd());
It's highly unlikely that you would need to do this. Why not just replace CButton with CColorbutton in your dialog's .h file?
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"Show me a community that obeys the Ten Commandments and I'll show you a less crowded prison system." - Anonymous
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