RWModel Class Reference

Implements the "Model" leg of a Model-View-Controller architecture. More...

#include <rw/model.h>

Public Member Functions
	RWModel ()
	RWModel (const RWModel &m)
	RWModel (RWModel &&m)
void	addDependent (RWModelClient *m)
virtual void	changed (void *d=0)
const RWOrdered *	dependents () const
RWModel &	operator= (const RWModel &m)
RWModel &	operator= (RWModel &&m)
void	removeDependent (RWModelClient *m)
void	swap (RWModel &m)

Detailed Description

This abstract base class has been designed to implement the "Model" leg of a Model-View-Controller architecture. A companion class, RWModelClient, supplies the "View" leg.

It maintains a list of dependent RWModelClient objects. When member function changed(void*) is called, the list of dependents is traversed, calling RWModelClient::updateFrom(RWModel*, void*) for each one, with itself as the first argument. Subclasses of RWModelClient should be prepared to accept such a call.

Synopsis

#include <rw/model.h>
(abstract base class)

Persistence

None

Example

#include <iostream>
#include <rw/model.h>

class Dial : public RWModelClient
{
    int dialNumber;
public:
    explicit Dial(int dialNumber);
    virtual void
    updateFrom(RWModel* m, void* d);
};

class Thermostat : public RWModel
{
    double setting;
public:
    Thermostat( Dial* d ) {
        addDependent (d);
        setting = 0;
    }
    double temperature() const {
        return setting;
    }
    void setTemperature(double t) {
        setting = t;
        changed ();
    }
};

void Dial::updateFrom(RWModel* m, void*)
{
    Thermostat* t = (Thermostat*)m;
    double temp = t -> temperature ();

    // Redraw graphic.
    std::cout << "Dial #" << dialNumber << " says " << temp << std::endl;
}

Dial::Dial (int num) : dialNumber (num)
{
}

int main ()
{
    Dial one(1);
    Dial two(2);

    Thermostat therm(&one);

    therm.setTemperature(77);
    therm.setTemperature(-4);
    therm.addDependent(&two);
    therm.setTemperature(47);
    return 0;
}

Program output:

Dial #1 says 77
Dial #1 says -4
Dial #1 says 47
Dial #2 says 47

Constructor & Destructor Documentation

RWModel::RWModel

(

)

Sets up the internal ordered list of dependents when called by the specializing class.

RWModel::RWModel

(

const RWModel &

m

)

Copy constructor. The constructed instance gets a copy of the dependents list from m.

RWModel::RWModel

(

RWModel &&

m

)

Move constructor. The constructed instance takes ownership of the dependents list owned by m.

Condition:

This method is available only on platforms with rvalue reference support.

Member Function Documentation

void RWModel::addDependent

(

RWModelClient *

m

)

Adds the object pointed to by m to the list of dependents of self.

virtual void RWModel::changed ( void *  d = 0 )

virtual

Traverse the internal list of dependents, calling member function RWModelClient::updateFrom(RWModel*, void*) for each one, with self as the first argument and d as the second argument.

const RWOrdered* RWModel::dependents ( ) const

inline

Allows a peek at the dependent list.

RWModel& RWModel::operator=

(

const RWModel &

m

)

Assignment operator. Self gets a copy of the dependents list from m.

RWModel& RWModel::operator=

(

RWModel &&

m

)

Move assignment. Self takes ownership of the dependents list owned by m.

Condition:

This method is available only on platforms with rvalue reference support.

void RWModel::removeDependent

(

RWModelClient *

m

)

Removes the object pointed to by m from the list of dependents of self.

void RWModel::swap

(

RWModel &

m

)

Swaps the list of dependents in self with that of m.