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1 """A call-tip window class for Tkinter/IDLE.
2 
3 After tooltip.py, which uses ideas gleaned from PySol.
4 Used by calltip.py.
5 """
6 from tkinter import Label, LEFT, SOLID, TclError
7 
8 from idlelib.tooltip import TooltipBase
9 
10 HIDE_EVENT = "<<calltipwindow-hide>>"
11 HIDE_SEQUENCES = ("<Key-Escape>", "<FocusOut>")
12 CHECKHIDE_EVENT = "<<calltipwindow-checkhide>>"
13 CHECKHIDE_SEQUENCES = ("<KeyRelease>", "<ButtonRelease>")
14 CHECKHIDE_TIME = 100  # milliseconds
15 
16 MARK_RIGHT = "calltipwindowregion_right"
17 
18 
19 class CalltipWindow(TooltipBase):
20     """A call-tip widget for tkinter text widgets."""
21 
22     def __init__(self, text_widget):
23         """Create a call-tip; shown by showtip().
24 
25         text_widget: a Text widget with code for which call-tips are desired
26         """
27         # Note: The Text widget will be accessible as self.anchor_widget
28         super(CalltipWindow, self).__init__(text_widget)
29 
30         self.label = self.text = None
31         self.parenline = self.parencol = self.lastline = None
32         self.hideid = self.checkhideid = None
33         self.checkhide_after_id = None
34 
35     def get_position(self):
36         """Choose the position of the call-tip."""
37         curline = int(self.anchor_widget.index("insert").split('.')[0])
38         if curline == self.parenline:
39             anchor_index = (self.parenline, self.parencol)
40         else:
41             anchor_index = (curline, 0)
42         box = self.anchor_widget.bbox("%d.%d" % anchor_index)
43         if not box:
44             box = list(self.anchor_widget.bbox("insert"))
45             # align to left of window
46             box[0] = 0
47             box[2] = 0
48         return box[0] + 2, box[1] + box[3]
49 
50     def position_window(self):
51         "Reposition the window if needed."
52         curline = int(self.anchor_widget.index("insert").split('.')[0])
53         if curline == self.lastline:
54             return
55         self.lastline = curline
56         self.anchor_widget.see("insert")
57         super(CalltipWindow, self).position_window()
58 
59     def showtip(self, text, parenleft, parenright):
60         """Show the call-tip, bind events which will close it and reposition it.
61 
62         text: the text to display in the call-tip
63         parenleft: index of the opening parenthesis in the text widget
64         parenright: index of the closing parenthesis in the text widget,
65                     or the end of the line if there is no closing parenthesis
66         """
67         # Only called in calltip.Calltip, where lines are truncated
68         self.text = text
69         if self.tipwindow or not self.text:
70             return
71 
72         self.anchor_widget.mark_set(MARK_RIGHT, parenright)
73         self.parenline, self.parencol = map(
74             int, self.anchor_widget.index(parenleft).split("."))
75 
76         super(CalltipWindow, self).showtip()
77 
78         self._bind_events()
79 
80     def showcontents(self):
81         """Create the call-tip widget."""
82         self.label = Label(self.tipwindow, text=self.text, justify=LEFT,
83                            background="#ffffd0", foreground="black",
84                            relief=SOLID, borderwidth=1,
85                            font=self.anchor_widget['font'])
86         self.label.pack()
87 
88     def checkhide_event(self, event=None):
89         """Handle CHECK_HIDE_EVENT: call hidetip or reschedule."""
90         if not self.tipwindow:
91             # If the event was triggered by the same event that unbound
92             # this function, the function will be called nevertheless,
93             # so do nothing in this case.
94             return None
95 
96         # Hide the call-tip if the insertion cursor moves outside of the
97         # parenthesis.
98         curline, curcol = map(int, self.anchor_widget.index("insert").split('.'))
99         if curline < self.parenline or \
100            (curline == self.parenline and curcol <= self.parencol) or \
101            self.anchor_widget.compare("insert", ">", MARK_RIGHT):
102             self.hidetip()
103             return "break"
104 
105         # Not hiding the call-tip.
106 
107         self.position_window()
108         # Re-schedule this function to be called again in a short while.
109         if self.checkhide_after_id is not None:
110             self.anchor_widget.after_cancel(self.checkhide_after_id)
111         self.checkhide_after_id = \
112             self.anchor_widget.after(CHECKHIDE_TIME, self.checkhide_event)
113         return None
114 
115     def hide_event(self, event):
116         """Handle HIDE_EVENT by calling hidetip."""
117         if not self.tipwindow:
118             # See the explanation in checkhide_event.
119             return None
120         self.hidetip()
121         return "break"
122 
123     def hidetip(self):
124         """Hide the call-tip."""
125         if not self.tipwindow:
126             return
127 
128         try:
129             self.label.destroy()
130         except TclError:
131             pass
132         self.label = None
133 
134         self.parenline = self.parencol = self.lastline = None
135         try:
136             self.anchor_widget.mark_unset(MARK_RIGHT)
137         except TclError:
138             pass
139 
140         try:
141             self._unbind_events()
142         except (TclError, ValueError):
143             # ValueError may be raised by MultiCall
144             pass
145 
146         super(CalltipWindow, self).hidetip()
147 
148     def _bind_events(self):
149         """Bind event handlers."""
150         self.checkhideid = self.anchor_widget.bind(CHECKHIDE_EVENT,
151                                                    self.checkhide_event)
152         for seq in CHECKHIDE_SEQUENCES:
153             self.anchor_widget.event_add(CHECKHIDE_EVENT, seq)
154         self.anchor_widget.after(CHECKHIDE_TIME, self.checkhide_event)
155         self.hideid = self.anchor_widget.bind(HIDE_EVENT,
156                                               self.hide_event)
157         for seq in HIDE_SEQUENCES:
158             self.anchor_widget.event_add(HIDE_EVENT, seq)
159 
160     def _unbind_events(self):
161         """Unbind event handlers."""
162         for seq in CHECKHIDE_SEQUENCES:
163             self.anchor_widget.event_delete(CHECKHIDE_EVENT, seq)
164         self.anchor_widget.unbind(CHECKHIDE_EVENT, self.checkhideid)
165         self.checkhideid = None
166         for seq in HIDE_SEQUENCES:
167             self.anchor_widget.event_delete(HIDE_EVENT, seq)
168         self.anchor_widget.unbind(HIDE_EVENT, self.hideid)
169         self.hideid = None
170 
171 
172 def _calltip_window(parent):  # htest #
173     from tkinter import Toplevel, Text, LEFT, BOTH
174 
175     top = Toplevel(parent)
176     top.title("Test call-tips")
177     x, y = map(int, parent.geometry().split('+')[1:])
178     top.geometry("250x100+%d+%d" % (x + 175, y + 150))
179     text = Text(top)
180     text.pack(side=LEFT, fill=BOTH, expand=1)
181     text.insert("insert", "string.split")
182     top.update()
183 
184     calltip = CalltipWindow(text)
185     def calltip_show(event):
186         calltip.showtip("(s='Hello world')", "insert", "end")
187     def calltip_hide(event):
188         calltip.hidetip()
189     text.event_add("<<calltip-show>>", "(")
190     text.event_add("<<calltip-hide>>", ")")
191     text.bind("<<calltip-show>>", calltip_show)
192     text.bind("<<calltip-hide>>", calltip_hide)
193 
194     text.focus_set()
195 
196 if __name__ == '__main__':
197     from unittest import main
198     main('idlelib.idle_test.test_calltip_w', verbosity=2, exit=False)
199 
200     from idlelib.idle_test.htest import run
201     run(_calltip_window)
202