桥接模式（C++）

桥接模式：主要应用于需求复杂，不确定的场景，用于解耦

#include <iostream>
using namespace std;
 
// Implementor
class DrawAPI
{
public:
    virtual void drawCircle(int radius, int x, int y) = 0;
    virtual ~DrawAPI() {}
};
 
// ConcreteImplementorA
class RedCircle : public DrawAPI
{
public:
    void drawCircle(int radius, int x, int y) override
    {
        cout << "Drawing Circle[ color: red, radius: " << radius << ", x: " << x << ", y: " << y << " ]" << endl;
    }
};
 
// ConcreteImplementorB
class GreenCircle : public DrawAPI
{
public:
    void drawCircle(int radius, int x, int y) override
    {
        cout << "Drawing Circle[ color: green, radius: " << radius << ", x: " << x << ", y: " << y << " ]" << endl;
    }
};
 
// Abstraction
class Shape
{
protected:
    DrawAPI *drawAPI;
    Shape(DrawAPI *drawAPI) : drawAPI(drawAPI) {}
public:
    virtual void draw() = 0;
    virtual ~Shape() {}
};
 
// RefinedAbstraction
class Circle : public Shape
{
private:
    int x, y, radius;
public:
    Circle(int x, int y, int radius, DrawAPI *drawAPI) : Shape(drawAPI), x(x), y(y), radius(radius) {}
    void draw() override
    {
        drawAPI->drawCircle(radius, x, y);
    }
};
 
// Client code
int main()
{
    Shape *redCircle = new Circle(100, 100, 10, new RedCircle());
    Shape *greenCircle = new Circle(100, 100, 10, new GreenCircle());
 
    redCircle->draw();
    greenCircle->draw();
 
    delete redCircle;
    delete greenCircle;
 
    return 0;
}
 

在这个例子中，DrawAPI 是实现类接口，RedCircle 和 GreenCircle 是具体的实现类。Shape 是抽象类，而 Circle 是扩展抽象类。通过这种方式，Circle 类的实现可以独立于画圆的颜色，从而实现了代码的解耦