"""Tools for displaying tool-tips.
This includes:
* an abstract base-class for different kinds of tooltips
* a simple text-only Tooltip class
"""
from tkinter import *
class TooltipBase:
"""abstract base class for tooltips"""
def __init__(self, anchor_widget):
"""Create a tooltip.
anchor_widget: the widget next to which the tooltip will be shown
Note that a widget will only be shown when showtip() is called.
"""
self.anchor_widget = anchor_widget
self.tipwindow = None
def __del__(self):
self.hidetip()
def showtip(self):
"""display the tooltip"""
if self.tipwindow:
return
self.tipwindow = tw = Toplevel(self.anchor_widget)
# show no border on the top level window
tw.wm_overrideredirect(1)
try:
# This command is only needed and available on Tk >= 8.4.0 for OSX.
# Without it, call tips intrude on the typing process by grabbing
# the focus.
tw.tk.call("::tk::unsupported::MacWindowStyle", "style", tw._w,
"help", "noActivates")
except TclError:
pass
self.position_window()
self.showcontents()
self.tipwindow.update_idletasks() # Needed on MacOS -- see #34275.
self.tipwindow.lift() # work around bug in Tk 8.5.18+ (issue #24570)
def position_window(self):
"""(re)-set the tooltip's screen position"""
x, y = self.get_position()
root_x = self.anchor_widget.winfo_rootx() + x
root_y = self.anchor_widget.winfo_rooty() + y
self.tipwindow.wm_geometry("+%d+%d" % (root_x, root_y))
def get_position(self):
"""choose a screen position for the tooltip"""
# The tip window must be completely outside the anchor widget;
# otherwise when the mouse enters the tip window we get
# a leave event and it disappears, and then we get an enter
# event and it reappears, and so on forever :-(
#
# Note: This is a simplistic implementation; sub-classes will likely
# want to override this.
return 20, self.anchor_widget.winfo_height() + 1
def showcontents(self):
"""content display hook for sub-classes"""
# See ToolTip for an example
raise NotImplementedError
def hidetip(self):
"""hide the tooltip"""
# Note: This is called by __del__, so careful when overriding/extending
tw = self.tipwindow
self.tipwindow = None
if tw:
try:
tw.destroy()
except TclError: # pragma: no cover
pass
class OnHoverTooltipBase(TooltipBase):
"""abstract base class for tooltips, with delayed on-hover display"""
def __init__(self, anchor_widget, hover_delay=1000):
"""Create a tooltip with a mouse hover delay.
anchor_widget: the widget next to which the tooltip will be shown
hover_delay: time to delay before showing the tooltip, in milliseconds
Note that a widget will only be shown when showtip() is called,
e.g. after hovering over the anchor widget with the mouse for enough
time.
"""
super().__init__(anchor_widget)
self.hover_delay = hover_delay
self._after_id = None
self._id1 = self.anchor_widget.bind("", self._show_event)
self._id2 = self.anchor_widget.bind("", self._hide_event)
self._id3 = self.anchor_widget.bind("