# ruler.tcl --
#
# This demonstration script creates a canvas widget that displays a ruler
# with tab stops that can be set, moved, and deleted.
#
# @(#) ruler.tcl 1.1 95/05/26 15:56:37
# rulerMkTab --
# This procedure creates a new triangular polygon in a canvas to
# represent a tab stop.
#
# Arguments:
# c - The canvas window.
# x, y - Coordinates at which to create the tab stop.
proc rulerMkTab {c x y} {
upvar #0 demo_rulerInfo v
$c create polygon $x $y [expr $x+$v(size)] [expr $y+$v(size)] \
[expr $x-$v(size)] [expr $y+$v(size)]
}
set w .ruler
global tk_library
catch {destroy $w}
toplevel $w
wm title $w "Ruler Demonstration"
wm iconname $w "ruler"
positionWindow $w
set c $w.c
label $w.msg -font $font -wraplength 5i -justify left -text "This canvas widget shows a mock-up of a ruler. You can create tab stops by dragging them out of the well to the right of the ruler. You can also drag existing tab stops. If you drag a tab stop far enough up or down so that it turns dim, it will be deleted when you release the mouse button."
pack $w.msg -side top
frame $w.buttons
pack $w.buttons -side bottom -expand y -fill x -pady 2m
button $w.buttons.dismiss -text Dismiss -command "destroy $w"
button $w.buttons.code -text "See Code" -command "showCode $w"
pack $w.buttons.dismiss $w.buttons.code -side left -expand 1
canvas $c -width 14.8c -height 2.5c
pack $w.c -side top -fill x
set demo_rulerInfo(grid) .25c
set demo_rulerInfo(left) [winfo fpixels $c 1c]
set demo_rulerInfo(right) [winfo fpixels $c 13c]
set demo_rulerInfo(top) [winfo fpixels $c 1c]
set demo_rulerInfo(bottom) [winfo fpixels $c 1.5c]
set demo_rulerInfo(size) [winfo fpixels $c .2c]
set demo_rulerInfo(normalStyle) "-fill black"
if {[winfo depth $c] > 1} {
set demo_rulerInfo(activeStyle) "-fill red -stipple {}"
set demo_rulerInfo(deleteStyle) \
"-stipple @$tk_library/demos/images/grey.25 -fill red"
} else {
set demo_rulerInfo(activeStyle) "-fill black -stipple {}"
set demo_rulerInfo(deleteStyle) \
"-stipple @$tk_library/demos/images/grey.25 -fill black"
}
$c create line 1c 0.5c 1c 1c 13c 1c 13c 0.5c -width 1
for {set i 0} {$i < 12} {incr i} {
set x [expr $i+1]
$c create line ${x}c 1c ${x}c 0.6c -width 1
$c create line $x.25c 1c $x.25c 0.8c -width 1
$c create line $x.5c 1c $x.5c 0.7c -width 1
$c create line $x.75c 1c $x.75c 0.8c -width 1
$c create text $x.15c .75c -text $i -anchor sw
}
$c addtag well withtag [$c create rect 13.2c 1c 13.8c 0.5c \
-outline black -fill [lindex [$c config -bg] 4]]
$c addtag well withtag [rulerMkTab $c [winfo pixels $c 13.5c] \
[winfo pixels $c .65c]]
$c bind well <1> "rulerNewTab $c %x %y"
$c bind tab <1> "rulerSelectTab $c %x %y"
bind $c <B1-Motion> "rulerMoveTab $c %x %y"
bind $c <Any-ButtonRelease-1> "rulerReleaseTab $c"
# rulerNewTab --
# Does all the work of creating a tab stop, including creating the
# triangle object and adding tags to it to give it tab behavior.
#
# Arguments:
# c - The canvas window.
# x, y - The coordinates of the tab stop.
proc rulerNewTab {c x y} {
upvar #0 demo_rulerInfo v
$c addtag active withtag [rulerMkTab $c $x $y]
$c addtag tab withtag active
set v(x) $x
set v(y) $y
rulerMoveTab $c $x $y
}
# rulerSelectTab --
# This procedure is invoked when mouse button 1 is pressed over
# a tab. It remembers information about the tab so that it can
# be dragged interactively.
#
# Arguments:
# c - The canvas widget.
# x, y - The coordinates of the mouse (identifies the point by
# which the tab was picked up for dragging).
proc rulerSelectTab {c x y} {
upvar #0 demo_rulerInfo v
set v(x) [$c canvasx $x $v(grid)]
set v(y) [expr $v(top)+2]
$c addtag active withtag current
eval "$c itemconf active $v(activeStyle)"
$c raise active
}
# rulerMoveTab --
# This procedure is invoked during mouse motion events to drag a tab.
# It adjusts the position of the tab, and changes its appearance if
# it is about to be dragged out of the ruler.
#
# Arguments:
# c - The canvas widget.
# x, y - The coordinates of the mouse.
proc rulerMoveTab {c x y} {
upvar #0 demo_rulerInfo v
if {[$c find withtag active] == ""} {
return
}
set cx [$c canvasx $x $v(grid)]
set cy [$c canvasy $y]
if {$cx < $v(left)} {
set cx $v(left)
}
if {$cx > $v(right)} {
set cx $v(right)
}
if {($cy >= $v(top)) && ($cy <= $v(bottom))} {
set cy [expr $v(top)+2]
eval "$c itemconf active $v(activeStyle)"
} else {
set cy [expr $cy-$v(size)-2]
eval "$c itemconf active $v(deleteStyle)"
}
$c move active [expr $cx-$v(x)] [expr $cy-$v(y)]
set v(x) $cx
set v(y) $cy
}
# rulerReleaseTab --
# This procedure is invoked during button release events that end
# a tab drag operation. It deselects the tab and deletes the tab if
# it was dragged out of the ruler.
#
# Arguments:
# c - The canvas widget.
# x, y - The coordinates of the mouse.
proc rulerReleaseTab c {
upvar #0 demo_rulerInfo v
if {[$c find withtag active] == {}} {
return
}
if {$v(y) != [expr $v(top)+2]} {
$c delete active
} else {
eval "$c itemconf active $v(normalStyle)"
$c dtag active
}
}