我想使用pygtk在图像上添加透明标签，它似乎不适用于我，标签覆盖了背景图片（滑块），我只能看到我的标签。我有想法让标签透明以便看到背景图片，有什么建议吗？
#!/usr/bin/python
# -*- coding: utf-8 -*-
import RPi.GPIO as GPIO
from time import sleep
import urllib2
import os
import xml.dom
import xml.dom.minidom
import pygtk
pygtk.require('2.0')
import gtk
import glib
#Configure the inputs/outputs
GPIO.setmode(GPIO.BCM)
GPIO.setup(4, GPIO.IN, pull_up_down = GPIO.PUD_UP) # The emplyee button
xmldoc = xml.dom.minidom.parse('/var/www/delay.xml')
delay = xmldoc.getElementsByTagName('delay')
def _begin():
if (GPIO.input(4)==0):
response=urllib2.urlopen("http://localhost/num.php?id_service=1",timeout=5) **#retrieve the next ticket number from MYSQL DB through an url**
number = response.read()
label = gtk.Label("9999 ") # for testing else it would be label= gtk.Label(number)**
response.close()
sleep(1);
return _begin()
def is_image(filename):
""" File is image if it has a common suffix and it is a regular file """
if not os.path.isfile(filename):
return False
for suffix in ['.jpg', '.png', '.bmp']:
if filename.lower().endswith(suffix):
return True
return False
def resizeToFit(image, frame, aspect=True, enlarge=False):
"""Resizes a rectangle to fit within another.
Parameters:
image -- A tuple of the original dimensions (width, height).
frame -- A tuple of the target dimensions (width, height).
aspect -- Maintain aspect ratio?
enlarge -- Allow image to be scaled up?
"""
if aspect:
return scaleToFit(image, frame, enlarge)
else:
return stretchToFit(image, frame, enlarge)
def scaleToFit(image, frame, enlarge=False):
image_width, image_height = image
frame_width, frame_height = frame
image_aspect = float(image_width) / image_height
frame_aspect = float(frame_width) / frame_height
# Determine maximum width/height (prevent up-scaling).
if not enlarge:
max_width = min(frame_width, image_width)
max_height = min(frame_height, image_height)
else:
max_width = frame_width
max_height = frame_height
# Frame is wider than image.
if frame_aspect > image_aspect:
height = max_height
width = int(height * image_aspect)
# Frame is taller than image.
else:
width = max_width
height = int(width / image_aspect)
return (width, height)
def stretchToFit(image, frame, enlarge=False):
image_width, image_height = image
frame_width, frame_height = frame
# Stop image from being blown up.
if not enlarge:
width = min(frame_width, image_width)
height = min(frame_height, image_height)
else:
width = frame_width
height = frame_height
return (width, height)
class ResizableImage(gtk.DrawingArea):
def __init__(self, aspect=True, enlarge=False,
interp=gtk.gdk.INTERP_NEAREST, backcolor=None, max=(1600,1200)):
"""Construct a ResizableImage control.
Parameters:
aspect -- Maintain aspect ratio?
enlarge -- Allow image to be scaled up?
interp -- Method of interpolation to be used.
backcolor -- Tuple (R, G, B) with values ranging from 0 to 1,
or None for transparent.
max -- Max dimensions for internal image (width, height).
"""
super(ResizableImage, self).__init__()
self.pixbuf = None
self.aspect = aspect
self.enlarge = enlarge
self.interp = interp
self.backcolor = backcolor
self.max = max
self.connect('expose_event', self.expose)
self.connect('realize', self.on_realize)
def on_realize(self, widget):
if self.backcolor is None:
color = gtk.gdk.Color()
else:
color = gtk.gdk.Color(*self.backcolor)
self.window.set_background(color)
def expose(self, widget, event):
# Load Cairo drawing context.
self.context = self.window.cairo_create()
# Set a clip region.
self.context.rectangle(
event.area.x, event.area.y,
event.area.width, event.area.height)
self.context.clip()
# Render image.
self.draw(self.context)
return False
def draw(self, context):
# Get dimensions.
rect = self.get_allocation()
x, y = rect.x, rect.y
# Remove parent offset, if any.
parent = self.get_parent()
if parent:
offset = parent.get_allocation()
x -= offset.x
y -= offset.y
# Fill background color.
if self.backcolor:
context.rectangle(x, y, rect.width, rect.height)
context.set_source_rgb(*self.backcolor)
context.fill_preserve()
# Check if there is an image.
if not self.pixbuf:
return
width, height = resizeToFit(
(self.pixbuf.get_width(), self.pixbuf.get_height()),
(rect.width, rect.height),
self.aspect,
self.enlarge)
x = x + (rect.width - width) / 2
y = y + (rect.height - height) / 2
context.set_source_pixbuf(
self.pixbuf.scale_simple(width, height, self.interp), x, y)
context.paint()
def set_from_pixbuf(self, pixbuf):
width, height = pixbuf.get_width(), pixbuf.get_height()
# Limit size of internal pixbuf to increase speed.
if not self.max or (width < self.max[0] and height < self.max[1]):
self.pixbuf = pixbuf
else:
width, height = resizeToFit((width, height), self.max)
self.pixbuf = pixbuf.scale_simple(
width, height,
gtk.gdk.INTERP_BILINEAR)
self.invalidate()
def set_from_file(self, filename):
self.set_from_pixbuf(gtk.gdk.pixbuf_new_from_file(filename))
def invalidate(self):
self.queue_draw()
class DemoGtk:
SECONDS_BETWEEN_PICTURES = int(delay[0].firstChild.nodeValue)
FULLSCREEN = True
WALK_INSTEAD_LISTDIR = True
def __init__(self):
self.window = gtk.Window()
self.window.connect('destroy', gtk.main_quit)
self.window.set_title('Slideshow')
self.image = ResizableImage( True, True, gtk.gdk.INTERP_BILINEAR)
self.image.show()
self.window.add(self.image)
self.window.add(label) # GO to def _begin there i declared the label with its value**
self.load_file_list()
self.window.show_all()
if self.FULLSCREEN:
self.window.fullscreen()
glib.timeout_add_seconds(self.SECONDS_BETWEEN_PICTURES, self.on_tick)
self.display()
def load_file_list(self):
""" Find all images """
self.files = []
self.index = 0
if self.WALK_INSTEAD_LISTDIR:
for directory, sub_directories, files in os.walk('.'):
for filename in files:
if is_image(filename):
filepath = os.path.join(directory, filename)
self.files.append(filepath)
else:
for filename in os.listdir('.'):
if is_image(filename):
self.files.append(filename)
print "Images:", self.files
def display(self):
""" Sent a request to change picture if it is possible """
if 0 <= self.index < len(self.files):
self.image.set_from_file(self.files[self.index])
return True
else:
return False
def on_tick(self):
""" Skip to another picture.
If this picture is last, go to the first one. """
self.index += 1
if self.index >= len(self.files):
self.index = 0
return self.display()
if __name__ == "__main__":
while 1:
gui = DemoGtk()
gtk.main()
_begin()
# vim: tabstop=4 expandtab shiftwidth=4 softtabstop=4