Calling overridden function within component of class - c++

I have 4 classes, Customer, PickyCustomer, SegmentCustomer, and Delivery.
The Delivery class has a component within it called customer, like so:
class Delivery {
private:
Customer *customer;
Delivery(Customer *cust) // constructor
each of the Customer classes have a method called getAcceptable()
that is overrideable and is overridden within PickyCustomer and SegmentCustomer
From what I've read this is the correct way to call the overridden method from the Delivery class. By keeping the customer as a pointer it allows Delivery to call the child methods that override the base class.
But when trying to use unique_ptr I keep getting the error
no matching function for call to 'Delivery::Delivery(std::unique_ptr<Customer>*)'
when using the following bit of code to initialize
unique_ptr<Customer> cust1(new Customer("Name", "Home", 1000.0, 25.0, fileProduce));
shared_ptr<Delivery> cust1Delivery(new Delivery(cust1));
Can someone explain why I am getting this error, and show how I could fix this? Thanks.

Thanks to #paddy in the comments with the help! Using the get() function worked for me.
The below works for me.
unique_ptr<Delivery> cust1Delivery(new Delivery(cust1.get()));

Related

A descendant of TStyledPresentationProxy has not been registered for class

I have a custom grid control that inherits from TGrid called TFmGrid. This control was working fine in Rad Studio 10 Seattle Update One. I recently upgraded to 10.1 Berlin and started noticing this error message showing up on my TFmGrid controls both when I run the application and in the designer:
A descendant of TStyledPresentationProxy has not been registered for class TFmGrid. Maybe it is necessary to add the FMX.Grid.Style module to the uses section
The image below shows how the error message shows up on my grid controls:
I started by doing as the message suggests, and adding #include <FMX.Grid.Style.hpp> to the header file of my TFmGrid control, however this seems to have done nothing.
So as far as trying to register a decendant of TStyledPresentationProxy I am not exactly sure where to start. I found this documentation about a method which:
Attempts to register the presentation proxy class with the specified name or the specified combination of control class and control type.
So I assume I need to use this method or at least something similar, but I don't understand how I am supposed to go about calling this method.
But then that brings up the question of WHERE do I call this code?
My custom control has a method in its namespace called Register() which I believe was autogenerated by the IDE when the control was created:
namespace Fmgridu
{
void __fastcall PACKAGE Register()
{
TComponentClass classes[1] = {__classid(TFmGrid)};
RegisterComponents(L"Kalos FM Controls", classes, 0);
}
}
Do I need to call something in there to register a decendant of TStyledPresentationProxy? What is the proper way to go about this?
Just override virtual method DefinePresentationName in you TfmGrid and return name of presentation name for grid:
function TfmGrid.DefinePresentationName: string;
begin
Result := 'Grid-' + GetPresentationSuffix;
end;
Fm registers presentation by string name and uses class name for it, so if you create new component (based on existed) you automatically change classname, so system cannot find presentation for you. There are two solution:
Said that you will use presentation from TGrid (DefinePresentationName)
Register existed presentation for you class (look at the initialization section of FMX.Grid.Style.pas)
P.S. Year ago i wrote article about it in common eNew approach of development of FireMonkey control “Control – Model – Presentation”. Part 1 I hope it will help you
It's simple :
Just put "StyleBook" component to your form
I had the same issue with a test component I was developing.
Complementing Yaroslav Brovin's speech, I solved the problem by adding the class register in the initialization and finalization clauses at the end of the unit, like this:
initialization
TPresentationProxyFactory.Current.Register(<COMPONENT CLASSNAME HERE>, TControlType.Styled, TStyledPresentationProxy<TStyledGrid>);
finalization
TPresentationProxyFactory.Current.Unregister(<COMPONENT CLASSNAME HERE>, TControlType.Styled, TStyledPresentationProxy<TStyledGrid>);
In my case looks like this:
initialization
TPresentationProxyFactory.Current.Register(TSGrid, TControlType.Styled, TStyledPresentationProxy<TStyledGrid>);
finalization
TPresentationProxyFactory.Current.Unregister(TSGrid, TControlType.Styled, TStyledPresentationProxy<TStyledGrid>);
PS: Don't forget to declare the FMX.Presentation.Factory,
FMX.Presentation.Style and FMX.Grid.Style units in the uses clause

Can I create a class inside other class? and call all together

im newbie in c++ so I hope you can help me in this.
i have this class Appearances, i show a bit of the code of the cpp
Appearances::Appearances(const char* id, float shininess,const char* textureref)
{this->id = id;
setShininess(shininess);
this->textureref = textureref;
}
and i want to join another class "Component" like this
Component(float ambient[4] , float diffuse[4] , float specular[4])
{setAmbient(ambient);
setDiffuse(diffuse);
setSpecular(specular);
}
And what I want is that i can call appearances with all of this joined, for example:
app = new Appearances(idAppearance, vAmb, vDif, vSpec, shininess, txtRef);
im trying to get this on c++
<appearance id="app1" shininess="6.0" textureref="ss" >
<component type="ambient" value="5 5 5 5" />
<component type="diffuse" value="5 5 5 5" />
<component type="specular" value="0.6 0.6 0.6 0.6" />
</appearance>
I dont know if I explained well what i want, but can someone help me? :)
To do that you would need to change your constructor to include the data of the component class.
Appearances::Appearances(const char* id,float ambient[4] , float diffuse[4] , float specular[4], float shininess,const char* textureref)
Then in the constructor you call the constructor of Component.
But this raise the question of design. If you can initialize your component, it means it just a logical group you want to do, i suggest to use nomenclature instead like comp_Ambient.
If you want to be able to have more than one component in your class, then you don't want to initialize it in the constructor.
The other reason I see to use this design, is being able to use component on other object, then, don't put it in the class.
Do you need full access to components members and functions? If so, I see two possible answers to your question. The simplest way would be to create a derived class which inherits from both Appearances and Component. For example, you could declare class Design: public Appearances, public Component. While multiple inheritance can sometimes complicate design, it seems to be the most straightforward option. See more here.
If you would like to add the functionality to the existing Appearances class, this can be done by making Component a friend class of Appearances. This is done by adding the line friend class Appearances; to your Component class, which allows Appearances to access all members of Component. In this case, you will also need to declare two constructors: one for initializing Appearances without Component, and one for initializing Appearances with the data for Component.

Spawning new async request from an asio handler

I'm trying to get my feet wet with ASIO and thought a good first project would be a simple web crawler: download an html page, find the links in it, download all the links.
I have tried modifying the ASIO http client example to use enable_shared_from_this instead of a raw pointer so that I can spawn new async task from within the handler of the previous task without having to worry about the resources getting deleted in the middle of my work.
The problems start when I tried to subclass my client to handle different pages in different ways. The compiler complains that the type of the shared_ptr doesn't match the type of this.
Does anybody know how this is solved? I haven't been able to figure it out by myself.
This is unrelated to Asio.
If you inherited a base class from enable_shared_from_this, but need it in the derived one, use boost::static_pointer_cast:
struct base : enable_shared_from_this<base>
{
};
struct derived : base
{
shared_ptr<derived> shared_from_derived()
{
return static_pointer_cast<derived>(shared_from_this());
}
};

Can Django pre_save signal work for all derived classes

I have a model class "Action" that get's extended by several other classes. I am new to django and assumed that if I called pre_save.connect(actionFunc, sender=Action) that actionFunc would get called anytime the save method in the Action class was called (including by any derived class).
My observation is that this function only gets triggered when the instance is a direct match of the Class type defined in Sender. Is there anyway to get this to recieve signals for all derived instances of Action as well?
No, you have to call the pre_save.connect as many number of times.
However, you can use python to get all the classes that extend the class of your interest, and loop over the pre_save connect statement.
Say, if the extended classes of the Action are all in a given file, you can do the following:
global_dict = globals().copy()
[el for el in global_dict.values() if getattr(el,'__base__',None)==Action]
one thing you can do is modify the signal sender in django so that instead of matching against a specific type it instead does
if isinstance(sender, filter):
send_signal()
(pseudocode)

Outlook Add-in. How to manage Items Events

I'm doing an add-in for Outlook 2007 in C++.
I need to capture the events like create, change or delete from the Outlook Items (Contact, Appointment, Tasks and Notes) but the only information/examples I've found are for Visual Basic so I don't know how to connect the event handler.
Here is some information related: http://msdn.microsoft.com/en-us/library/bb208390(v=office.12).aspx
Any help is welcome :) Thanks
Update
Sorry for taking this long to update, I've been out of town. I have some doubts/problems that you may know how to help.
In my case, I'm taking this project that was started so I'm a bit confused about all this. I have the class OutlookAddin that derives from IDTExtensibility2. I also have this other class, called AutoSync, were I'd like to do all the methods when the event fires and so. An object of this class is initialized in OutlookAddin.cpp OnStartupComplete.
According to your post MyClass should extends from IDispEventSimpleImpl<1 /*N*/, MyClass, &__uuidof(Outlook::ItemsEvents)> but which one of them? OutlookAddin or AutoSync ?
Where I should put this code also?
CComPtr<Outlook::MAPIFolder> folder;
// get the folder you're interested in
CComPtr<Outlook::_Items> items;
hr = folder->get_Items(&items);
hr = MyItemEvents::DispEventAdvise(items, &__uuidof(Outlook::ItemsEvents));
typedef IDispEventSimpleImpl<1 /*N*/, MyClass,
&__uuidof(Outlook::ItemsEvents)> MyItemEvents;
I've read the links you posted but still having these doubts...
Update 2
This is more complicated to understand than I though in a first instance.
So I have like this:
OutlookAddin.h
class OutlookAddin :
public IDTExtensibility2,
public IDispEventSimpleImpl<1, OutlookAddin, &__uuidof(Outlook::ItemEvents)>
...
BEGIN_SINK_MAP(OutlookAddin)
SINK_ENTRY_INFO(1, __uuidof(Outlook::ItemEvents), 0xf002, OutlookAddin::OnItemChange, &OnSimpleEventInfo)
END_SINK_MAP()
...
void __stdcall OnItemChange();
'OnSimpleEventInfo' is defined like:
extern _ATL_FUNC_INFO OnSimpleEventInfo;
_ATL_FUNC_INFO OnSimpleEventInfo = {CC_STDCALL,VT_EMPTY,0};
then in OutlookAddin.cpp, OnConnection method:
CComPtr<Outlook::MAPIFolder> folder;
CComPtr<Outlook::_Items> items;
OutlookWorker::GetInstance()->GetNameSpacePtr()->GetDefaultFolder(olFolderContacts, &folder);
folder->get_Items(&items);
DispEventAdvise(items, &__uuidof(Outlook::ItemsEvents));
being 'OutlookWorker::GetInstance()->GetNameSpacePtr()' the _NameSpacePtr where all the environment is kept.
The expected behaviour here is to fire the function 'OnItemChange' from OutlookAddin class when an ContactItem is created/edited/deleted but that's not happening... I changed a little bit the structure to everything is in the main class OutlookAddin. Then on the function 'OnItemChange' I'll start the object of 'AutoSync' that I told you before.
Anyway I'm following the articles you gave me, really useful, thank you. Do you still have any other suggestion for me?
Thanks your patience.
Its been a while, but you should get these item events by advising for Folder.Items:
CComPtr<Outlook::MAPIFolder> folder;
// get the folder you're interested in
CComPtr<Outlook::_Items> items;
hr = folder->get_Items(&items);
hr = MyItemEvents::DispEventAdvise(items, &__uuidof(Outlook::ItemsEvents));
Where your class MyClass derives from:
IDispEventSimpleImpl<1 /*N*/, MyClass, &__uuidof(Outlook::ItemsEvents)>
And MyItemEvents is:
typedef IDispEventSimpleImpl<1 /*N*/, MyClass,
&__uuidof(Outlook::ItemsEvents)> MyItemEvents;
N identifies your sink here. Then there is the joy of the remaining macros to setup and the handler functions to implement - i refer you to this and this article for examples and to the dispinterface ItemsEvents that you can look up in oleview.exe.
Regarding update 1:
If you want to receive the events in AutoSync, implement the interface there - you are not required to sink the events to any specific instance. However, you know your design best :)
I'd just personally keep as much logic out of the central addin class as possible.
The registration code would go into some method of the class implementing the events then and called whenever it should start to receive events, while the typedef would be e.g. well placed in the class' declaration.
Regarding update 2:
From a quick glance it looks mostly right, but OnItemChange() takes one parameter - an IDispatch:
_ATL_FUNC_INFO AtlCallDispatch = {CC_STDCALL, VT_EMPTY, 1, {VT_DISPATCH}};