The document presents a C++ program using the FLTK library to create a graphical user interface with three buttons. A custom button class is defined to handle various button events and log them to the console. The main function initializes a window and sets up callbacks for each button to display messages when they are interacted with.

1. 1 #include <iostream>
2 #include <FL/Fl.H>
3 #include <FL/Fl_Window.H>
4 #include <FL/Fl_Button.H>
5
6 /*Declaração de namespace para uso das funções de iostream*/
7 using namespace std;
8
9 /**
10 * Classe para verificação de eventos em um botão ...
11 **/
12 class MyButton : public Fl_Button
13 {
14 /*Variável estática para contagem de eventos*/
15 static int count;
16
17 public:
18
19 /*Construtor*/
20 MyButton(int x,int y,int w,int h,const char*l=0):Fl_Button(x,y,w,h,l){};
21
22 /*Sobreposição do método manipulador de eventos*/
23 int handle(int event)
24 {
25 int retorno = Fl_Button::handle(event);
26 cout << endl << count++ << " ******** button " << this->label() << " receives ";
27
28 switch(event)
29 {
30 case FL_PUSH:
31 cout << "push" << " event and returns:" << retorno << endl;
32 break;
33
34 case FL_RELEASE:
35 cout << "release" << " event and returns:" << retorno << endl;
36 break;
37
38 case FL_ENTER:
39 color(FL_CYAN);
40 cout << "enter" << " event and returns:" << retorno << endl;
41 redraw();
42 break;
43
44 case FL_LEAVE:
45 color(FL_BACKGROUND_COLOR);
46 cout << "leave" << " event and returns:" << retorno << endl;
47 redraw();
48 break;
49
50 case FL_DRAG:
51 cout << "drag" << " event and returns:" << retorno << endl;
52 break;
53
54 case FL_FOCUS:
55 cout << "focus" << " event and returns:" << retorno << endl;
56 break;
57
58 case FL_UNFOCUS:
59 cout << "unfocus" << " event and returns:" << retorno << endl;
60 break;
61
62 case FL_KEYDOWN:
63 cout << "keydown" << " event and returns:" << retorno << endl;
64 break;
65
66 case FL_KEYUP:
67 if ( Fl::event_key() == shortcut() )
68 {
69 box(FL_UP_BOX);
70 redraw();
71 retorno = 1; //return handled so keyup event stops
72 } //being sent to ALL other buttons unecessarily

2. 73
74 cout << "keyup" << " event and returns:" << retorno << endl;
75 break;
76
77 case FL_CLOSE:
78 cout << "close" << " event and returns:" << retorno << endl;
79 break;
80
81 case FL_MOVE:
82 cout << "move" << " event and returns:" << retorno << endl;
83 break;
84
85 case FL_SHORTCUT:
86 if ( Fl::event_key() == shortcut() )
87 {
88 box(FL_DOWN_BOX);
89 redraw();
90 }
91 cout << "shortcut" << " event and returns:" << retorno << endl;
92 break;
93
94 case FL_DEACTIVATE:
95 cout << "deactivate" << " event and returns:" << retorno << endl;
96 break;
97
98 case FL_ACTIVATE:
99 cout << "activate" << " event and returns:" << retorno << endl;
100 break;
101
102 case FL_HIDE:
103 cout << "hide" << " event and returns:" << retorno << endl;
104 break;
105
106 case FL_SHOW:
107 cout << "show" << " event and returns:" << retorno << endl;
108 break;
109
110 case FL_PASTE:
111 cout << "paste" << " event and returns:" << retorno << endl;
112 break;
113
114 case FL_SELECTIONCLEAR:
115 cout << "selectionclear" << " event and returns:" << retorno << endl;
116 break;
117
118 case FL_MOUSEWHEEL:
119 cout << "mousewheel" << " event and returns:" << retorno << endl;
120 break;
121
122 case FL_NO_EVENT:
123 cout << "no event" << " and returns:" << retorno << endl;
124 break;
125 }
126
127 /*Retorno do método ...*/
128 return(retorno);
129 }
130 };
131
132 /**
133 * Atribuição inicial da variável estática ...
134 */
135 int MyButton::count=0;
136
137 /**
138 * Funções que respondem aos callbacks
139 */
140 void but_a_cb(Fl_Widget* w, void* v)
141 {
142 cout << endl << "Button A callback!" << endl;
143 }
144

3. 145 void but_b_cb(Fl_Widget* w, void* v)
146 {
147 cout << endl << "Button B callback!" << endl;
148 }
149
150 void but_c_cb(Fl_Widget* w, void* v)
151 {
152 cout << endl << "Button C callback!" << endl;
153 }
154
155 /**
156 * Função principal do programa.
157 */
158 int main(int argc, char* argv[])
159 {
160 Fl_Window win(120,150);
161 win.begin();
162 MyButton but_a(10,10,100,25,"A");
163 but_a.shortcut('a');
164 but_a.callback(but_a_cb);
165 MyButton but_b(10,50,100,25,"B");
166 but_b.shortcut('b');
167 but_b.callback(but_b_cb);
168 MyButton but_c(10,90,100,25,"C");
169 but_c.shortcut('c');
170 but_c.callback(but_c_cb);
171 win.end();
172 win.show();
173 return(Fl::run());
174 }
175