我不明白如何在 FLTK 中制作按钮

I don't understand how to make buttons in FLTK

本文关键字:按钮 FLTK 明白      更新时间:2023-10-16
#include "std_lib_facilities_4.h"
#include "Window.h"
#include "Graph.h"
#include "GUI.h"
#include <FL/Fl_Image.H>
using namespace Graph_lib;
using namespace std;
struct Lines_window:Graph_lib::Window{
    Lines_window(Point xy, int w, int h, const string& title);
    Button button_1;
    Button button_2;
    static void cb_change_color(Address, Address);
    static void cb_change_picture(Address, Address);
};
Lines_window::Lines_window(Point xy, int w, int h, const string& title) :
    Window(xy, w, h, title),
    button_1(Point(x_max()/2, y_max()/2), 200, 100, "Button 1", cb_change_color),
    button_2(Point(x_max()/3, y_max()/3), 200, 100, "Button 2", cb_change_picture)
    {
        attach(button_1);
        attach(button_2);
    }
void Lines_window::cb_change_color(Address, Address pw)
{
}
void Lines_window::cb_change_picture(Address, Address pw)
{
}

int main()
try {
    if(H112 != 201401L)error("Error: incorrect std_lib_facilities_4.h version ", H112);
    using namespace Graph_lib;
    Lines_window win(Point(100,100),600,400,"Buttons");
    return gui_main();
    return 0;
}
catch(exception& e) {
    cerr << "exception: " << e.what() << 'n';
    return 1;
}
catch (...) {
    cerr << "Some exceptionn";
    return 2;
}

这是我的按钮代码。我正在尝试制作两个按钮,一个在按下按钮时会改变颜色,另一个按钮会在您按下按钮时将图像放在按钮上。我还没有进行回调,因为这不会编译。错误是:

GUI.cpp:16:6: error: prototype for ‘void Graph_lib::Button::attach(Graph_lib::Window&, Fl_Color)’ does not match any in class ‘Graph_lib::Button’
 void Button::attach(Window& win, Fl_Color color)
      ^
In file included from GUI.cpp:10:0:
GUI.h:66:14: error: candidate is: virtual void Graph_lib::Button::attach(Graph_lib::Window&)
         void attach(Window&);
              ^

我需要回调来编译吗?我在这里基于我教授的代码来编写此代码。除了纽扣之外,我把所有东西都拿出来了,这样我就可以制作它们了。GUI.cpp 和 GUI.h 给了我们。我做错了什么?

图形用户界面

.cpp
//
// This is a GUI support code to the chapters 12-16 of the book
// "Programming -- Principles and Practice Using C++" by Bjarne Stroustrup
//
#include <FL/Fl.H>
#include <FL/Fl_Button.H>
#include <FL/Fl_Output.H>
#include "GUI.h"
namespace Graph_lib {
//------------------------------------------------------------------------------
void Button::attach(Window& win, Fl_Color color)
{
    pw = new Fl_Button(loc.x, loc.y, width, height, label.c_str());
    pw->color(BLUE);
    pw->callback(reinterpret_cast<Fl_Callback*>(do_it), &win); // pass the window
    own = &win;
}
//------------------------------------------------------------------------------
int In_box::get_int()
{
    Fl_Input& pi = reference_to<Fl_Input>(pw);
    // return atoi(pi.value());
    const char* p = pi.value();
    if (!isdigit(p[0])) return -999999;
    return atoi(p);
}
//------------------------------------------------------------------------------
string In_box::get_string()
{
    Fl_Input& pi = reference_to<Fl_Input>(pw);
    return string(pi.value());
}
//------------------------------------------------------------------------------
void In_box::attach(Window& win)
{
    pw = new Fl_Input(loc.x, loc.y, width, height, label.c_str());
    own = &win;
}
//------------------------------------------------------------------------------
void Out_box::put(const string& s)
{
    reference_to<Fl_Output>(pw).value(s.c_str());
}
//------------------------------------------------------------------------------
void Out_box::attach(Window& win)
{
    pw = new Fl_Output(loc.x, loc.y, width, height, label.c_str());
    own = &win;
}
//------------------------------------------------------------------------------
int Menu::attach(Button& b)
{
    b.width = width;
    b.height = height;
    switch(k) {
    case horizontal:
        b.loc = Point(loc.x+offset,loc.y);
        offset+=b.width;
        break;
    case vertical:
        b.loc = Point(loc.x,loc.y+offset);
        offset+=b.height;
        break;
    }
    selection.push_back(b); // b is NOT OWNED: pass by reference
    return int(selection.size()-1);
}
//------------------------------------------------------------------------------
int Menu::attach(Button* p)
{
    Button& b = *p;
    b.width = width;
    b.height = height;
    switch(k) {
    case horizontal:
        b.loc = Point(loc.x+offset,loc.y);
        offset+=b.width;
        break;
    case vertical:
        b.loc = Point(loc.x,loc.y+offset);
        offset+=b.height;
        break;
    }
    selection.push_back(&b); // b is OWNED: pass by pointer
    return int(selection.size()-1);
}
//------------------------------------------------------------------------------
} // of namespace Graph_lib

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//
// This is a GUI support code to the chapters 12-16 of the book
// "Programming -- Principles and Practice Using C++" by Bjarne Stroustrup
//
#ifndef GUI_GUARD
#define GUI_GUARD
#include "Window.h"
#include "Graph.h"
namespace Graph_lib {
//------------------------------------------------------------------------------
    typedef void* Address;    // Address is a synonym for void*
    typedef void(*Callback)(Address, Address);    // FLTK's required function type for all callbacks
//------------------------------------------------------------------------------
    template<class W> W& reference_to(Address pw)
    // treat an address as a reference to a W
    {
        return *static_cast<W*>(pw);
    }
//------------------------------------------------------------------------------
    class Widget {
    // Widget is a handle to an Fl_widget - it is *not* an Fl_widget
    // We try to keep our interface classes at arm's length from FLTK
    public:
        Widget(Point xy, int w, int h, const string& s, Callback cb)
            : loc(xy), width(w), height(h), label(s), do_it(cb)
        {}
        virtual void move(int dx,int dy) { hide(); pw->position(loc.x+=dx, loc.y+=dy); show(); }
        virtual void hide() { pw->hide(); }
        virtual void show() { pw->show(); }
        virtual void attach(Window&) = 0;
        Point loc;
        int width;
        int height;
        string label;
        Callback do_it;
        virtual ~Widget() { }
    protected:
        Window* own;    // every Widget belongs to a Window
        Fl_Widget* pw;  // connection to the FLTK Widget
    private:
        Widget& operator=(const Widget&); // don't copy Widgets
        Widget(const Widget&);
    };
//------------------------------------------------------------------------------
    struct Button : Widget {
        Button(Point xy, int w, int h, const string& label, Callback cb)
            : Widget(xy,w,h,label,cb)
        {}
        void attach(Window&);
    };
//------------------------------------------------------------------------------
    struct In_box : Widget {
        In_box(Point xy, int w, int h, const string& s)
            :Widget(xy,w,h,s,0) { }
        int get_int();
        string get_string();
        void attach(Window& win);
    };
//------------------------------------------------------------------------------
    struct Out_box : Widget {
        Out_box(Point xy, int w, int h, const string& s)
            :Widget(xy,w,h,s,0) { }
        void put(int);
        void put(const string&);
        void attach(Window& win);
    };
//------------------------------------------------------------------------------
    struct Menu : Widget {
        enum Kind { horizontal, vertical };
        Menu(Point xy, int w, int h, Kind kk, const string& label)
            : Widget(xy,w,h,label,0), k(kk), offset(0)
        {}
        Vector_ref<Button> selection;
        Kind k;
        int offset;
        int attach(Button& b);      // Menu does not delete &b
        int attach(Button* p);      // Menu deletes p
        void show()                 // show all buttons
        {
            for (unsigned int i = 0; i<selection.size(); ++i)
                selection[i].show();
        }
        void hide()                 // hide all buttons
        {
            for (unsigned int i = 0; i<selection.size(); ++i) 
                selection[i].hide(); 
        }
        void move(int dx, int dy)   // move all buttons
        {
            for (unsigned int i = 0; i<selection.size(); ++i) 
                selection[i].move(dx,dy);
        }
        void attach(Window& win)    // attach all buttons
        {
            for (int i=0; i<selection.size(); ++i) win.attach(selection[i]);
            own = &win;
        }
    };
//------------------------------------------------------------------------------
} // of namespace Graph_lib
#endif // GUI_GUARD

我找到了答案。它不会编译,因为我添加了一个要传递给按钮(Fl_Color)的参数。我将不得不想办法将值传递给按钮以更改颜色。