如何让 ttk.Scale 表现得更像 tk.Scale?
How to make ttk.Scale behave more like tk.Scale?
几个 Tk 小部件也存在于 Ttk 版本中。通常它们具有相同的一般行为,但使用 "styles" 和 "themes" 而不是 per-instance 外观属性(例如 bg
等)。这很好,因为 Ttk 小部件默认采用 OS 的 window 管理器的 "standard appearance",无需配置任何外观。
但是,由于某些原因,ttk.Scale
小部件没有 tk.Scale
小部件的两个非常有用的选项:showvalue
和 tickinterval
(请参阅 reference).这很奇怪,因为那些更多的是关于行为而不是外观。
如果 "immitate" 这两个选项同时保持 ttk
外观,那就太好了。
以下代码是我对此的笨拙尝试。问题是:有没有更好的方法? (显然除了将整个东西封装在 class 中)以及如何合理地获得 semi-automated tickinterval
替代品(而不是像下面的代码那样 "by hand" ) .
import tkinter as tk
import tkinter.ttk as ttk
# initial setup
root = tk.Tk()
frame = tk.Frame(root)
#################################################################
# create a tk slider showing current value and ticks
# (showvalue=True is the default)
tkslider = tk.Scale(frame, from_=-4, to=4,
orient=tk.HORIZONTAL, tickinterval=2)
#################################################################
#################################################################
# create a ttk slider showing current value and ticks
# use a ttk frame to get ttk style background
ttkslider = ttk.Frame(frame)
# define a callback function to update the value label
def ttk_slider_callback(value):
# 'value' seems to be a string - bug or feature?
value_label.config(text=round(float(value)))
# 'text' can apparently be an int and gets converted into str
# (...) possibly do other stuff
# decompose frame into two ttk labels and a ttk scale
value_label = ttk.Label(ttkslider, text=0)
actual_slider = ttk.Scale(ttkslider, from_=-4, to=4,
command=ttk_slider_callback)
# (orient=tk.HORIZONTAL is the default)
ticks_label = ttk.Label(ttkslider, text=' -4 -2 0 2 4 ')
# put it all together
value_label.grid()
actual_slider.grid()
ticks_label.grid()
#################################################################
# final setup
tkslider.grid(row=0, column=0)
ttkslider.grid(row=0, column=1)
frame.grid()
root.mainloop()
前面代码的结果,在实际 "sliding" 比例尺之前,可能看起来像这样,左边是 Tk 比例尺,右边是 Ttk 比例尺(每个 OS / window 经理):
您可以自动放置刻度和显示值的标签 place
及其位置 x(以像素为单位)由公式给出:
x = ((value - start) / extent) * (width - sliderlength) + sliderlength / 2
与:
value
: 分时值
start
:刻度的起点(即from
选项)
extent
: 结束 - 开始
width
:刻度的宽度
((value - start) / extent)
以百分比给出位置,然后,我只需要将它乘以刻度的长度,但要考虑滑块的长度。
然后打勾:
place(in_=self.scale, bordermode='outside', x=x, rely=1, anchor='n')
(使用 rely=0, anchor='s'
作为显示值的标签)
下面是完整代码。我还添加了对 digits
选项的支持。
import tkinter as tk
import tkinter.ttk as ttk
class TtkScale(ttk.Frame):
def __init__(self, master=None, **kwargs):
ttk.Frame.__init__(self, master)
self.columnconfigure(0, weight=1)
self.showvalue = kwargs.pop('showvalue', True)
self.tickinterval = kwargs.pop('tickinterval', 0)
self.digits = kwargs.pop('digits', '0')
if 'command' in kwargs:
# add self.display_value to the command
fct = kwargs['command']
def cmd(value):
fct(value)
self.display_value(value)
kwargs['command'] = cmd
else:
kwargs['command'] = self.display_value
self.scale = ttk.Scale(self, **kwargs)
# get slider length
style = ttk.Style(self)
style_name = kwargs.get('style', '%s.TScale' % (str(self.scale.cget('orient')).capitalize()))
self.sliderlength = style.lookup(style_name, 'sliderlength', default=30)
self.extent = kwargs['to'] - kwargs['from_']
self.start = kwargs['from_']
# showvalue
if self.showvalue:
ttk.Label(self, text=' ').grid(row=0)
self.label = ttk.Label(self, text='0')
self.label.place(in_=self.scale, bordermode='outside', x=0, y=0, anchor='s')
self.display_value(self.scale.get())
self.scale.grid(row=1, sticky='ew')
# ticks
if self.tickinterval:
ttk.Label(self, text=' ').grid(row=2)
self.ticks = []
self.ticklabels = []
nb_interv = round(self.extent/self.tickinterval)
formatter = '{:.' + str(self.digits) + 'f}'
for i in range(nb_interv + 1):
tick = kwargs['from_'] + i * self.tickinterval
self.ticks.append(tick)
self.ticklabels.append(ttk.Label(self, text=formatter.format(tick)))
self.ticklabels[i].place(in_=self.scale, bordermode='outside', x=0, rely=1, anchor='n')
self.place_ticks()
self.scale.bind('<Configure>', self.on_configure)
def convert_to_pixels(self, value):
return ((value - self.start)/ self.extent) * (self.scale.winfo_width()- self.sliderlength) + self.sliderlength / 2
def display_value(self, value):
# position (in pixel) of the center of the slider
x = self.convert_to_pixels(float(value))
# pay attention to the borders
half_width = self.label.winfo_width() / 2
if x + half_width > self.scale.winfo_width():
x = self.scale.winfo_width() - half_width
elif x - half_width < 0:
x = half_width
self.label.place_configure(x=x)
formatter = '{:.' + str(self.digits) + 'f}'
self.label.configure(text=formatter.format(float(value)))
def place_ticks(self):
# first tick
tick = self.ticks[0]
label = self.ticklabels[0]
x = self.convert_to_pixels(tick)
half_width = label.winfo_width() / 2
if x - half_width < 0:
x = half_width
label.place_configure(x=x)
# ticks in the middle
for tick, label in zip(self.ticks[1:-1], self.ticklabels[1:-1]):
x = self.convert_to_pixels(tick)
label.place_configure(x=x)
# last tick
tick = self.ticks[-1]
label = self.ticklabels[-1]
x = self.convert_to_pixels(tick)
half_width = label.winfo_width() / 2
if x + half_width > self.scale.winfo_width():
x = self.scale.winfo_width() - half_width
label.place_configure(x=x)
def on_configure(self, event):
"""Redisplay the ticks and the label so that they adapt to the new size of the scale."""
self.display_value(self.scale.get())
self.place_ticks()
if __name__ == '__main__':
root = tk.Tk()
root.geometry('400x300')
style = ttk.Style(root)
style.configure('my.Horizontal.TScale', sliderlength=10)
s1 = tk.Scale(root, orient='horizontal', tickinterval=0.2, from_=-1,
to=1, showvalue=True, resolution=0.1, sliderlength=10)
s2 = TtkScale(root, style='my.Horizontal.TScale', orient='horizontal',
tickinterval=0.2, from_=-1, to=1, showvalue=True,
digits=1)
ttk.Label(root, text='tk.Scale').pack()
s1.pack(fill='x')
ttk.Label(root, text='ttk.Scale').pack()
s2.pack(fill='x')
root.mainloop()
此小部件的更完整版本在 ttkwidgets 模块中可用,名称为 TickScale。
几个 Tk 小部件也存在于 Ttk 版本中。通常它们具有相同的一般行为,但使用 "styles" 和 "themes" 而不是 per-instance 外观属性(例如 bg
等)。这很好,因为 Ttk 小部件默认采用 OS 的 window 管理器的 "standard appearance",无需配置任何外观。
但是,由于某些原因,ttk.Scale
小部件没有 tk.Scale
小部件的两个非常有用的选项:showvalue
和 tickinterval
(请参阅 reference).这很奇怪,因为那些更多的是关于行为而不是外观。
如果 "immitate" 这两个选项同时保持 ttk
外观,那就太好了。
以下代码是我对此的笨拙尝试。问题是:有没有更好的方法? (显然除了将整个东西封装在 class 中)以及如何合理地获得 semi-automated tickinterval
替代品(而不是像下面的代码那样 "by hand" ) .
import tkinter as tk
import tkinter.ttk as ttk
# initial setup
root = tk.Tk()
frame = tk.Frame(root)
#################################################################
# create a tk slider showing current value and ticks
# (showvalue=True is the default)
tkslider = tk.Scale(frame, from_=-4, to=4,
orient=tk.HORIZONTAL, tickinterval=2)
#################################################################
#################################################################
# create a ttk slider showing current value and ticks
# use a ttk frame to get ttk style background
ttkslider = ttk.Frame(frame)
# define a callback function to update the value label
def ttk_slider_callback(value):
# 'value' seems to be a string - bug or feature?
value_label.config(text=round(float(value)))
# 'text' can apparently be an int and gets converted into str
# (...) possibly do other stuff
# decompose frame into two ttk labels and a ttk scale
value_label = ttk.Label(ttkslider, text=0)
actual_slider = ttk.Scale(ttkslider, from_=-4, to=4,
command=ttk_slider_callback)
# (orient=tk.HORIZONTAL is the default)
ticks_label = ttk.Label(ttkslider, text=' -4 -2 0 2 4 ')
# put it all together
value_label.grid()
actual_slider.grid()
ticks_label.grid()
#################################################################
# final setup
tkslider.grid(row=0, column=0)
ttkslider.grid(row=0, column=1)
frame.grid()
root.mainloop()
前面代码的结果,在实际 "sliding" 比例尺之前,可能看起来像这样,左边是 Tk 比例尺,右边是 Ttk 比例尺(每个 OS / window 经理):
您可以自动放置刻度和显示值的标签 place
及其位置 x(以像素为单位)由公式给出:
x = ((value - start) / extent) * (width - sliderlength) + sliderlength / 2
与:
value
: 分时值start
:刻度的起点(即from
选项)extent
: 结束 - 开始width
:刻度的宽度
((value - start) / extent)
以百分比给出位置,然后,我只需要将它乘以刻度的长度,但要考虑滑块的长度。
然后打勾:
place(in_=self.scale, bordermode='outside', x=x, rely=1, anchor='n')
(使用 rely=0, anchor='s'
作为显示值的标签)
下面是完整代码。我还添加了对 digits
选项的支持。
import tkinter as tk
import tkinter.ttk as ttk
class TtkScale(ttk.Frame):
def __init__(self, master=None, **kwargs):
ttk.Frame.__init__(self, master)
self.columnconfigure(0, weight=1)
self.showvalue = kwargs.pop('showvalue', True)
self.tickinterval = kwargs.pop('tickinterval', 0)
self.digits = kwargs.pop('digits', '0')
if 'command' in kwargs:
# add self.display_value to the command
fct = kwargs['command']
def cmd(value):
fct(value)
self.display_value(value)
kwargs['command'] = cmd
else:
kwargs['command'] = self.display_value
self.scale = ttk.Scale(self, **kwargs)
# get slider length
style = ttk.Style(self)
style_name = kwargs.get('style', '%s.TScale' % (str(self.scale.cget('orient')).capitalize()))
self.sliderlength = style.lookup(style_name, 'sliderlength', default=30)
self.extent = kwargs['to'] - kwargs['from_']
self.start = kwargs['from_']
# showvalue
if self.showvalue:
ttk.Label(self, text=' ').grid(row=0)
self.label = ttk.Label(self, text='0')
self.label.place(in_=self.scale, bordermode='outside', x=0, y=0, anchor='s')
self.display_value(self.scale.get())
self.scale.grid(row=1, sticky='ew')
# ticks
if self.tickinterval:
ttk.Label(self, text=' ').grid(row=2)
self.ticks = []
self.ticklabels = []
nb_interv = round(self.extent/self.tickinterval)
formatter = '{:.' + str(self.digits) + 'f}'
for i in range(nb_interv + 1):
tick = kwargs['from_'] + i * self.tickinterval
self.ticks.append(tick)
self.ticklabels.append(ttk.Label(self, text=formatter.format(tick)))
self.ticklabels[i].place(in_=self.scale, bordermode='outside', x=0, rely=1, anchor='n')
self.place_ticks()
self.scale.bind('<Configure>', self.on_configure)
def convert_to_pixels(self, value):
return ((value - self.start)/ self.extent) * (self.scale.winfo_width()- self.sliderlength) + self.sliderlength / 2
def display_value(self, value):
# position (in pixel) of the center of the slider
x = self.convert_to_pixels(float(value))
# pay attention to the borders
half_width = self.label.winfo_width() / 2
if x + half_width > self.scale.winfo_width():
x = self.scale.winfo_width() - half_width
elif x - half_width < 0:
x = half_width
self.label.place_configure(x=x)
formatter = '{:.' + str(self.digits) + 'f}'
self.label.configure(text=formatter.format(float(value)))
def place_ticks(self):
# first tick
tick = self.ticks[0]
label = self.ticklabels[0]
x = self.convert_to_pixels(tick)
half_width = label.winfo_width() / 2
if x - half_width < 0:
x = half_width
label.place_configure(x=x)
# ticks in the middle
for tick, label in zip(self.ticks[1:-1], self.ticklabels[1:-1]):
x = self.convert_to_pixels(tick)
label.place_configure(x=x)
# last tick
tick = self.ticks[-1]
label = self.ticklabels[-1]
x = self.convert_to_pixels(tick)
half_width = label.winfo_width() / 2
if x + half_width > self.scale.winfo_width():
x = self.scale.winfo_width() - half_width
label.place_configure(x=x)
def on_configure(self, event):
"""Redisplay the ticks and the label so that they adapt to the new size of the scale."""
self.display_value(self.scale.get())
self.place_ticks()
if __name__ == '__main__':
root = tk.Tk()
root.geometry('400x300')
style = ttk.Style(root)
style.configure('my.Horizontal.TScale', sliderlength=10)
s1 = tk.Scale(root, orient='horizontal', tickinterval=0.2, from_=-1,
to=1, showvalue=True, resolution=0.1, sliderlength=10)
s2 = TtkScale(root, style='my.Horizontal.TScale', orient='horizontal',
tickinterval=0.2, from_=-1, to=1, showvalue=True,
digits=1)
ttk.Label(root, text='tk.Scale').pack()
s1.pack(fill='x')
ttk.Label(root, text='ttk.Scale').pack()
s2.pack(fill='x')
root.mainloop()
此小部件的更完整版本在 ttkwidgets 模块中可用,名称为 TickScale。