编辑：在python 3.6，linux，gtk 3.22上运行
我写了一个简单的应用程序，它在一个文件夹中显示图像，并允许使用箭头键（通常是一个简单的漫画查看器;通过高度＆gt;宽度的图像尝试它）来浏览它们。每个图像都放大了，因此要查看其底部，您需要向下滚动。当您加载下一个图像时，应用程序应将滚动条还原到上半部分。我的当前代码只有在我按下右箭头键查看下一个图像之前等待几秒钟（即滚动条消失所需的时间）才能正确执行此操作，否则它会将下一个图像加载到底部。我不明白为什么。
编辑：请注意，只有在使用触摸板滚动时才会出现错误，而不是在拖动滚动条时。
#!/usr/bin/python3
import sys
import os
from gi import require_version
require_version('Gtk', '3.0')
from gi.repository import Gtk, Gdk, GdkPixbuf
class Comic:
def __init__(self, filelist):
self.files = filelist
self.index = 0
self.zoom = 0.50
self.window = Gtk.Window()
self.window.props.can_focus = False
self.window.props.default_width = 1366
self.window.props.default_height = 768
self.window.props.startup_id = 'app.comic'
self.window.props.title = 'comic'
self.window.connect("delete-event", Gtk.main_quit)
self.window.connect("key-press-event", self._on_key_press)
self.scrolledwindow = Gtk.ScrolledWindow()
self.scrolledwindow.props.visible = True
self.scrolledwindow.props.can_focus = True
self.scrolledwindow.props.hexpand = True
self.scrolledwindow.props.vexpand = True
self.window.add(self.scrolledwindow)
self.image = Gtk.Image()
self.scrolledwindow.add(self.image)
self._open_image()
def _on_key_press(self, win, ev):
key = Gdk.keyval_name(ev.keyval)
if key in ('Left', 'KP_Left'):
self.previous_image()
elif key in ('Right', 'KP_Right'):
self.next_image()
elif key == 'q':
Gtk.main_quit()
def _on_resize(self):
scrolled_allocation = self.scrolledwindow.get_allocation()
w = self.image_width
h = self.image_height
if h > scrolled_allocation.height:
scale = scrolled_allocation.height / h
w *= scale
h *= scale
if w > scrolled_allocation.width:
scale = scrolled_allocation.width / w
w *= scale
h *= scale
w = int(w)
h = int(h)
w = w + w * self.zoom
h = h + h * self.zoom
if (w != self.image_width or h != self.image_height) and w > 0 and h > 0:
pixbuf = self.pixbuf.scale_simple(w, h, GdkPixbuf.InterpType.BILINEAR)
self.image.set_from_pixbuf(pixbuf)
self.image_width = pixbuf.get_width()
self.image_height = pixbuf.get_height()
def _open_image(self):
filename = self.files[self.index]
self.pixbuf = GdkPixbuf.Pixbuf()
self.pixbuf = self.pixbuf.new_from_file(filename)
self.image.set_from_pixbuf(self.pixbuf)
self.image_width = self.pixbuf.get_width()
self.image_height = self.pixbuf.get_height()
self._on_resize()
return True
def previous_image(self):
self.index -= 1
if self.index <= -1:
self.index = 0
return True
self._open_image()
def next_image(self):
self.index += 1
if self.index >= len(self.files):
self.index = len(self.files) - 1
return True
self._open_image()
self._scroll_up()
def _scroll_up(self):
adj = Gtk.Adjustment()
adj.set_value(0.0)
self.scrolledwindow.set_vadjustment(adj)
def main():
directory = sys.argv[1]
ext = ('.jpg', '.jpe', '.jpeg', '.png', )
images = [os.path.join(directory, f) for f in sorted(os.listdir(directory)) if f.lower().endswith(ext)]
win = Comic(images)
win.window.show_all()
Gdk.threads_enter()
Gtk.main()
Gdk.threads_leave()
if __name__ == "__main__":
sys.exit(main())