| 4.3. Programa de Demostración de Empaquetamiento | ||
|---|---|---|
 | Capítulo 4. Empaquetamiento de Controles |  |
| 4.3. Programa de Demostración de Empaquetamiento | ||
|---|---|---|
| | Capítulo 4. Empaquetamiento de Controles | |
Aqui está el código usado para crear la imágen de arriba. Esta bastante comentado asi que espero que no tengas ningún problema siguiendolo. Ejecútalo y juega con él.
1 #!/usr/bin/env python
2
3 # example packbox.py
4
5 import gtk
6 import sys, string
7
8 # Helper function that makes a new hbox filled with button-labels. Arguments
9 # for the variables we're interested are passed in to this function. We do
10 # not show the box, but do show everything inside.
11
12 def make_box(homogeneous, spacing, expand, fill, padding):
13
14 # Create a new hbox with the appropriate homogeneous
15 # and spacing settings
16 box = gtk.HBox(homogeneous, spacing)
17
18 # Create a series of buttons with the appropriate settings
19 button = gtk.Button("box.pack")
20 box.pack_start(button, expand, fill, padding)
21 button.show()
22
23 button = gtk.Button("(button,")
24 box.pack_start(button, expand, fill, padding)
25 button.show()
26
27 # Create a button with the label depending on the value of
28 # expand.
29 if expand == gtk.TRUE:
30 button = gtk.Button("TRUE,")
31 else:
32 button = gtk.Button("FALSE,")
33
34 box.pack_start(button, expand, fill, padding)
35 button.show()
36
37 # This is the same as the button creation for "expand"
38 # above, but uses the shorthand form.
39 button = gtk.Button(("FALSE,", "TRUE,")[fill==gtk.TRUE])
40 box.pack_start(button, expand, fill, padding)
41 button.show()
42
43 padstr = "%d)" % padding
44
45 button = gtk.Button(padstr)
46 box.pack_start(button, expand, fill, padding)
47 button.show()
48 return box
49
50 class PackBox1:
51 def delete_event(self, widget, event, data=None):
52 gtk.main_quit()
53 return gtk.FALSE
54
55 def __init__(self, which):
56
57 # Create our window
58 self.window = gtk.Window(gtk.WINDOW_TOPLEVEL)
59
60 # You should always remember to connect the delete_event signal
61 # to the main window. This is very important for proper intuitive
62 # behavior
63 self.window.connect("delete_event", self.delete_event)
64 self.window.set_border_width(10)
65
66 # We create a vertical box (vbox) to pack the horizontal boxes into.
67 # This allows us to stack the horizontal boxes filled with buttons one
68 # on top of the other in this vbox.
69 box1 = gtk.VBox(gtk.FALSE, 0)
70
71 # which example to show. These correspond to the pictures above.
72 if which == 1:
73 # create a new label.
74 label = gtk.Label("HBox(FALSE, 0)")
75
76 # Align the label to the left side. We'll discuss this method
77 # and others in the section on Widget Attributes.
78 label.set_alignment(0, 0)
79
80 # Pack the label into the vertical box (vbox box1). Remember that
81 # widgets added to a vbox will be packed one on top of the other in
82 # order.
83 box1.pack_start(label, gtk.FALSE, gtk.FALSE, 0)
84
85 # Show the label
86 label.show()
87
88 # Call our make box function - homogeneous = FALSE, spacing = 0,
89 # expand = FALSE, fill = FALSE, padding = 0
90 box2 = make_box(gtk.FALSE, 0, gtk.FALSE, gtk.FALSE, 0)
91 box1.pack_start(box2, gtk.FALSE, gtk.FALSE, 0)
92 box2.show()
93
94 # Call our make box function - homogeneous = FALSE, spacing = 0,
95 # expand = TRUE, fill = FALSE, padding = 0
96 box2 = make_box(gtk.FALSE, 0, gtk.TRUE, gtk.FALSE, 0)
97 box1.pack_start(box2, gtk.FALSE, gtk.FALSE, 0)
98 box2.show()
99
100 # Args are: homogeneous, spacing, expand, fill, padding
101 box2 = make_box(gtk.FALSE, 0, gtk.TRUE, gtk.TRUE, 0)
102 box1.pack_start(box2, gtk.FALSE, gtk.FALSE, 0)
103 box2.show()
104
105 # Creates a separator, we'll learn more about these later,
106 # but they are quite simple.
107 separator = gtk.HSeparator()
108
109 # Pack the separator into the vbox. Remember each of these
110 # widgets is being packed into a vbox, so they'll be stacked
111 # vertically.
112 box1.pack_start(separator, gtk.FALSE, gtk.TRUE, 5)
113 separator.show()
114
115 # Create another new label, and show it.
116 label = gtk.Label("HBox(TRUE, 0)")
117 label.set_alignment(0, 0)
118 box1.pack_start(label, gtk.FALSE, gtk.FALSE, 0)
119 label.show()
120
121 # Args are: homogeneous, spacing, expand, fill, padding
122 box2 = make_box(gtk.TRUE, 0, gtk.TRUE, gtk.FALSE, 0)
123 box1.pack_start(box2, gtk.FALSE, gtk.FALSE, 0)
124 box2.show()
125
126 # Args are: homogeneous, spacing, expand, fill, padding
127 box2 = make_box(gtk.TRUE, 0, gtk.TRUE, gtk.TRUE, 0)
128 box1.pack_start(box2, gtk.FALSE, gtk.FALSE, 0)
129 box2.show()
130
131 # Another new separator.
132 separator = gtk.HSeparator()
133 # The last 3 arguments to pack_start are:
134 # expand, fill, padding.
135 box1.pack_start(separator, gtk.FALSE, gtk.TRUE, 5)
136 separator.show()
137 elif which == 2:
138 # Create a new label, remember box1 is a vbox as created
139 # near the beginning of __init__()
140 label = gtk.Label("HBox(FALSE, 10)")
141 label.set_alignment( 0, 0)
142 box1.pack_start(label, gtk.FALSE, gtk.FALSE, 0)
143 label.show()
144
145 # Args are: homogeneous, spacing, expand, fill, padding
146 box2 = make_box(gtk.FALSE, 10, gtk.TRUE, gtk.FALSE, 0)
147 box1.pack_start(box2, gtk.FALSE, gtk.FALSE, 0)
148 box2.show()
149
150 # Args are: homogeneous, spacing, expand, fill, padding
151 box2 = make_box(gtk.FALSE, 10, gtk.TRUE, gtk.TRUE, 0)
152 box1.pack_start(box2, gtk.FALSE, gtk.FALSE, 0)
153 box2.show()
154
155 separator = gtk.HSeparator()
156 # The last 3 arguments to pack_start are:
157 # expand, fill, padding.
158 box1.pack_start(separator, gtk.FALSE, gtk.TRUE, 5)
159 separator.show()
160
161 label = gtk.Label("HBox(FALSE, 0)")
162 label.set_alignment(0, 0)
163 box1.pack_start(label, gtk.FALSE, gtk.FALSE, 0)
164 label.show()
165
166 # Args are: homogeneous, spacing, expand, fill, padding
167 box2 = make_box(gtk.FALSE, 0, gtk.TRUE, gtk.FALSE, 10)
168 box1.pack_start(box2, gtk.FALSE, gtk.FALSE, 0)
169 box2.show()
170
171 # Args are: homogeneous, spacing, expand, fill, padding
172 box2 = make_box(gtk.FALSE, 0, gtk.TRUE, gtk.TRUE, 10)
173 box1.pack_start(box2, gtk.FALSE, gtk.FALSE, 0)
174 box2.show()
175
176 separator = gtk.HSeparator()
177 # The last 3 arguments to pack_start are:
178 # expand, fill, padding.
179 box1.pack_start(separator, gtk.FALSE, gtk.TRUE, 5)
180 separator.show()
181
182 elif which == 3:
183
184 # This demonstrates the ability to use pack_end() to
185 # right justify widgets. First, we create a new box as before.
186 box2 = make_box(gtk.FALSE, 0, gtk.FALSE, gtk.FALSE, 0)
187
188 # Create the label that will be put at the end.
189 label = gtk.Label("end")
190 # Pack it using pack_end(), so it is put on the right
191 # side of the hbox created in the make_box() call.
192 box2.pack_end(label, gtk.FALSE, gtk.FALSE, 0)
193 # Show the label.
194 label.show()
195
196 # Pack box2 into box1
197 box1.pack_start(box2, gtk.FALSE, gtk.FALSE, 0)
198 box2.show()
199
200 # A separator for the bottom.
201 separator = gtk.HSeparator()
202
203 # This explicitly sets the separator to 400 pixels wide by 5
204 # pixels high. This is so the hbox we created will also be 400
205 # pixels wide, and the "end" label will be separated from the
206 # other labels in the hbox. Otherwise, all the widgets in the
207 # hbox would be packed as close together as possible.
208 separator.set_usize(400, 5)
209 # pack the separator into the vbox (box1) created near the start
210 # of __init__()
211 box1.pack_start(separator, gtk.FALSE, gtk.TRUE, 5)
212 separator.show()
213
214 # Create another new hbox.. remember we can use as many as we need!
215 quitbox = gtk.HBox(gtk.FALSE, 0)
216
217 # Our quit button.
218 button = gtk.Button("Quit")
219
220 # Setup the signal to terminate the program when the button is clicked
221 button.connect_object("clicked", gtk.mainquit, self.window)
222 # Pack the button into the quitbox.
223 # The last 3 arguments to pack_start are:
224 # expand, fill, padding.
225 quitbox.pack_start(button, gtk.TRUE, gtk.FALSE, 0)
226 # pack the quitbox into the vbox (box1)
227 box1.pack_start(quitbox, gtk.FALSE, gtk.FALSE, 0)
228
229 # Pack the vbox (box1) which now contains all our widgets, into the
230 # main window.
231 self.window.add(box1)
232
233 # And show everything left
234 button.show()
235 quitbox.show()
236
237 box1.show()
238 # Showing the window last so everything pops up at once.
239 self.window.show()
240
241 def main():
242 # And of course, our main loop.
243 gtk.main()
244 # Control returns here when main_quit() is called
245 return 0
246
247 if __name__ =="__main__":
248 if len(sys.argv) != 2:
249 sys.stderr.write("usage: packbox.py num, where num is 1, 2, or 3.\n")
250 sys.exit(1)
251 PackBox1(string.atoi(sys.argv[1]))
252 main()
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El pequeño tour por el código packbox.py empieza por las lineas 12-48 que definen una función auxiliar que crea una caja horizontal y la rellena con botones según los parámetros específicados. Devuelve una referencia a la caja horizontal.
Las lineas 55-239 definen el método de inicialización __init__() de la clase PackBox1 que crea una ventana y una caja vertical dentro de ella que se rellena con una configuración de controles dependiendo del argumento que se le pase. Si se le pasa un 1, las lineas 73-136 crean una ventana mostrando las cinco únicas posibilidades que hay cuando variamos los parámetros homogeneous, expand y fill. Si se le pasa un 2, las lineas 138-180 crean una ventana mostrando las diferentes combinaciones de fill con spacing y padding. Finalmente, si le pasamos un 3, las lineas 186-212 crean una ventana mostrando el uso del método pack_start() para justificar los botones a la izquierda y el método pack_end() para justificar una etiqueta a la derecha. Las lineas 215-235 crean una caja horizontal que contiene un botón que se empaqueta dentro de la caja vertical. La señal 'clicked' del botón está conectada a la función PyGTK main_quit() para terminar el programa.
Las lineas 248-250 comprueba los argumentos de la linea de comandos y terminan el programa usando la función sys.exit() si no hay exactamente un argumento. La linea 251 crea una instancia de PackBox1. La linea 252 llama a la función main() para empezar el bucle de procesamiento de eventos GTK.
En este programa de ejemplo, las referencias a los controles (excepto a la ventana) no se guardan en los atributos de instancia del objeto porque no se necesitan después.
| |  | |
| 4.2. Detalles de Cajas |  | 4.4. Uso de Tablas para Empaquetar |