1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
|
# --------------------------------------------------------------------------
#
# SendInit --
#
# Creates a "send" proc to replace the former Tk send command.
# Uses DDE services to simulate the transfer. This must be
# called before any drag&drop targets are registered. Otherwise
# they will pick up the wrong application name.
#
# The first trick is to determine a unique application name. This
# is what other applications will use to send to us. Tk used to
# do this for us.
#
# Note that we can generate the same name for two different Tk
# applications. This can happen if two Tk applications picking
# names at exactly the same time. [In the future, we should
# probably generate a name based upon a global system value, such
# as the handle of the main window ".".] The proc "SendVerify"
# below will verify that you have only one DDE server registered
# with this application's name.
#
# Arguments:
# myInterp Sets the application name explicitly to this
# string. If the argument isn't given, or is the
# empty string, then the routine picks a name for
# us.
#
# Results:
# Returns the name of the application.
#
# Side Effects:
# Sets the name of our application. You can call "tk appname" to
# get the name. A DDE topic using the same name is also created.
# A send proc is also automatically created. Be careful that you
# don't overwrite an existing send command.
#
# --------------------------------------------------------------------------
proc SendInit { {myInterp ""} } {
# Load the DDE package.
package require dde
if { $myInterp == "" } {
# Pick a unique application name, replicating what Tk used to do.
# This is what other applications will use to "send" to us. We'll
# use DDE topics to represent interpreters.
set appName [tk appname]
set count 0
set suffix {}
# Keep generating interpreter names by suffix-ing the original
# application name with " #number". Sooner of later we'll find
# one that's not currently use.
while { 1 } {
set myInterp "${appName}${suffix}"
set myServer [list TclEval $myInterp]
if { [lsearch [dde services TclEval {}] $myServer] < 0 } {
break
}
incr count
set suffix " \#$count"
}
}
tk appname $myInterp
dde servername $myInterp
proc send { interp args } {
dde eval $interp $args
}
return $myInterp
}
# --------------------------------------------------------------------------
#
# SendVerify --
#
# Verifies that application name picked is uniquely registered
# as a DDE server. This checks that two Tk applications don't
# accidently use the same name.
#
# Arguments:
# None Used the current application name.
#
# Results:
# Generates an error if either a server can't be found or more
# than one server is registered.
#
# --------------------------------------------------------------------------
proc SendVerify {} {
# Load the DDE package.
package require dde
set count 0
set appName [tk appname]
foreach server [dde services TclEval {}] {
set topic [lindex $server 1]
if { [string compare $topic $appName] == 0 } {
incr count
}
}
if {$count == 0} {
error "Service not found: wrong name registered???"
}
if { $count > 1 } {
error "Duplicate names found for \"[tk appname]\""
}
}
|
