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
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
|
# ----------------------------------------------------------------------
#
# cbutton.tcl --
#
# Example of how to provide button-like behavior on canvas
# items. (Posted on comp.lang.tcl by Kevin Kenny)
#
# source: https://wiki.tcl-lang.org/page/Canvas+Buttons
set ::RCSID([info script]) \
{$Id: 1383,v 1.3 2006-09-24 06:00:06 jcw Exp $}
package provide canvasbutton 1.0
namespace eval canvasbutton {
# nexttag - Next unique tag number for a "button" being
# created
variable nexttag 0
# command - command(tag#) contains the command to execute when
# a "button" is selected.
variable command
# cursor - cursor(pathName) contains the (saved) cursor
# symbol of the widget when the pointer is in
# a "button"
variable cursor
# enteredButton - contains the tag number of the button
# containing the pointer.
variable enteredButton {}
# pressedButton - contains the tag number of the "button"
# in which the mouse button was pressed
variable pressedButton {}
namespace export canvasbutton
}
# ----------------------------------------------------------------------
#
# canvasbutton::canvasbutton --
#
# Create a button-like object on a canvas.
#
# Parameters:
# w Path name of the canvas
# x0 Canvas X co-ordinate of left edge
# y0 Canvas Y co-ordinate of top edge
# x1 Canvas X co-ordinate of right edge
# y1 Canvas Y co-ordinate of bottom edge
# text Text to display in the button
# cmd Command to execute when the button is selected.
#
# Results:
# Unique canvas tag assigned to the items that make
# up the button.
#
# Side effects:
# A rectangle and a text item are created in the canvas,
# and bindings are established to give them button-like
# behavior.
#
#----------------------------------------------------------------------
proc canvasbutton::canvasbutton {w x0 y0 wd h text cmd state} {
variable nexttag
variable command
set btag [list canvasb# [incr nexttag]]
set command($btag) $cmd
set x [expr { $x0 + ($wd / 2) }]
set y [expr { $y0 + ($h / 2) + 1}]
if {$state} {
$w create rectangle $x0 $y0 [expr {$x0 + $wd}] [expr {$y0 + $h}] \
-fill lightgray -outline black -width 1 \
-tags [list canvasb $btag [linsert $btag end frame]]
$w create text $x $y -anchor center -justify center \
-text $text \
-tags [list canvasb $btag [linsert $btag end text]]
$w bind canvasb <Enter> [list [namespace current]::enter %W]
$w bind canvasb <Leave> [list [namespace current]::leave %W]
$w bind canvasb <ButtonPress-1> \
[list [namespace current]::press %W]
$w bind canvasb <ButtonRelease-1> \
[list [namespace current]::release %W]
} else {
$w create rectangle $x0 $y0 [expr {$x0 + $wd}] [expr {$y0 + $h}] \
-fill lightgray -outline grey65 -width 1
$w create text $x $y -anchor center -justify center \
-text $text -fill grey65
}
return $btag
}
# ----------------------------------------------------------------------
#
# canvasbutton::enter --
#
# Process the <Enter> event on a canvas-button.
#
# Parameters:
# w Path name of the canvas
#
# Results:
# None.
#
# Side effects:
# When the mouse pointer is in a button, the button is
# highlighted with a broad outline and the cursor
# symbol changes to an arrow. When the active button
# is pressed, it is highlighted in green.
#
# ----------------------------------------------------------------------
proc canvasbutton::enter {w} {
variable enteredButton
variable pressedButton
variable cursor
set enteredButton [findBtag $w]
set frame [linsert $enteredButton end frame]
set cursor($w) [$w cget -cursor]
$w configure -cursor arrow
#$w itemconfigure $frame -width 3
$w itemconfigure $frame -fill grey93
if {![string compare $enteredButton $pressedButton]} {
$w itemconfigure $frame -fill grey60
}
}
# ----------------------------------------------------------------------
#
# canvasbutton::leave --
#
# Process the <Leave> event on a canvas-button.
#
# Parameters:
# w Path name of the canvas
#
# Results:
# None.
#
# Side effects:
# Reverts the cursor symbol, the border width
# if needed, the highlight color of the button.
#
# ----------------------------------------------------------------------
proc canvasbutton::leave {w} {
variable enteredButton
variable pressedButton
variable cursor
if {[string compare $enteredButton {}]} {
set btag [findBtag $w]
set frame [linsert $btag end frame]
#$w itemconfigure $frame -width 1
$w itemconfigure $frame -fill lightgray
$w configure -cursor $cursor($w)
unset cursor($w)
if {![string compare $btag $pressedButton]} {
$w itemconfigure $frame -fill white
}
set enteredButton {}
}
return
}
# ----------------------------------------------------------------------
#
# canvasbutton::press --
#
# Process the <ButtonPress-1> event on a canvas-button.
#
# Parameters:
# w Path name of the canvas
#
# Results:
# None.
#
# Side effects:
# Highlights the selected button in green.
#
# ----------------------------------------------------------------------
proc canvasbutton::press {w} {
variable pressedButton
set pressedButton [findBtag $w]
$w itemconfigure [linsert $pressedButton end frame] \
-fill grey60
return
}
# ----------------------------------------------------------------------
#
# canvasbutton::release --
#
# Process the <ButtonRelease-1> event on a canvas-button.
#
# Parameters:
# w Path name of the canvas
#
# Results:
# None.
#
# Side effects:
# Reverts the highlight color on the button. If the
# mouse has not left the button, invokes the button's
# command.
#
# ----------------------------------------------------------------------
proc canvasbutton::release {w} {
variable enteredButton
variable pressedButton
variable command
set pressedButtonWas $pressedButton
set pressedButton {}
$w itemconfigure [linsert $pressedButtonWas end frame] \
-fill grey93
if {![string compare $enteredButton $pressedButtonWas]} {
uplevel #0 $command($pressedButtonWas)
}
return
}
# ----------------------------------------------------------------------
#
# canvasbutton::btag --
#
# Locate the unique tag of a canvas-button
#
# Parameters:
# w Path name of the canvas
#
# Results:
# Button tag, or the null string if the current
# item is not a canvas-button
#
# Side effects:
# Searches the tag list of the current canvas item
# for a tag that begins with the string, `canvasb#',
# and returns the first two elements of the tag
# interpreted as a Tcl list.
#
# ----------------------------------------------------------------------
proc canvasbutton::findBtag {w} {
foreach tag [$w itemcget current -tags] {
if {[regexp {^canvasb#} [lindex $tag 0]]} {
return [lrange $tag 0 1]
}
}
return {}
}
if {![string compare $argv0 [info script]]} {
grid [canvas .c -width 300 -height 200 -cursor crosshair]
namespace import canvasbutton::*
.c create text 150 150 -anchor n -tags label \
-font {Helvetica 10 bold}
canvasbutton .c 10 60 90 140 "First\nButton" {
.c itemconfigure label -text One
}
canvasbutton .c 110 60 190 140 "Second\nButton" {
.c itemconfigure label -text Two
}
canvasbutton .c 210 60 290 140 "Third\nButton" {
.c itemconfigure label -text Three
}
canvasbutton .c 240 160 290 190 "Quit" exit
}
|
