"""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(object):
 """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:
 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(OnHoverTooltipBase, self).__init__(anchor_widget)
 self.hover_delay = hover_delay

 self._after_id = None
 self._id1 = self.anchor_widget.bind("<Enter>", self._show_event)
 self._id2 = self.anchor_widget.bind("<Leave>", self._hide_event)
 self._id3 = self.anchor_widget.bind("<Button>", self._hide_event)

 def __del__(self):
 try:
 self.anchor_widget.unbind("<Enter>", self._id1)
 self.anchor_widget.unbind("<Leave>", self._id2)
 self.anchor_widget.unbind("<Button>", self._id3)
 except TclError:
 pass
 super(OnHoverTooltipBase, self).__del__()

 def _show_event(self, event=None):
 """event handler to display the tooltip"""
 if self.hover_delay:
 self.schedule()
 else:
 self.showtip()

 def _hide_event(self, event=None):
 """event handler to hide the tooltip"""
 self.hidetip()

 def schedule(self):
 """schedule the future display of the tooltip"""
 self.unschedule()
 self._after_id = self.anchor_widget.after(self.hover_delay,
 self.showtip)

 def unschedule(self):
 """cancel the future display of the tooltip"""
 after_id = self._after_id
 self._after_id = None
 if after_id:
 self.anchor_widget.after_cancel(after_id)

 def hidetip(self):
 """hide the tooltip"""
 try:
 self.unschedule()
 except TclError:
 pass
 super(OnHoverTooltipBase, self).hidetip()


class Hovertip(OnHoverTooltipBase):
 "A tooltip that pops up when a mouse hovers over an anchor widget."
 def __init__(self, anchor_widget, text, hover_delay=1000):
 """Create a text 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(Hovertip, self).__init__(anchor_widget, hover_delay=hover_delay)
 self.text = text

 def showcontents(self):
 label = Label(self.tipwindow, text=self.text, justify=LEFT,
 background="#ffffe0", relief=SOLID, borderwidth=1)
 label.pack()


def _tooltip(parent): # htest #
 top = Toplevel(parent)
 top.title("Test tooltip")
 x, y = map(int, parent.geometry().split('+')[1:])
 top.geometry("+%d+%d" % (x, y + 150))
 label = Label(top, text="Place your mouse over buttons")
 label.pack()
 button1 = Button(top, text="Button 1 -- 1/2 second hover delay")
 button1.pack()
 Hovertip(button1, "This is tooltip text for button1.", hover_delay=500)
 button2 = Button(top, text="Button 2 -- no hover delay")
 button2.pack()
 Hovertip(button2, "This is tooltip\ntext for button2.", hover_delay=None)


if __name__ == '__main__':
 from unittest import main
 main('idlelib.idle_test.test_tooltip', verbosity=2, exit=False)

 from idlelib.idle_test.htest import run
 run(_tooltip)