# scrlbar.tcl --
#
# This file defines the default bindings for Tk scrollbar widgets.
# It also provides procedures that help in implementing the bindings.
#
# Copyright (c) 1994 The Regents of the University of California.
# Copyright (c) 1994-1996 Sun Microsystems, Inc.
#
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
#
#-------------------------------------------------------------------------
# The code below creates the default class bindings for scrollbars.
#-------------------------------------------------------------------------
# Standard Motif bindings:
if {[tk windowingsystem] eq "x11"} {
bind Scrollbar <Enter> {
if {$tk_strictMotif} {
set tk::Priv(activeBg) [%W cget -activebackground]
%W configure -activebackground [%W cget -background]
}
%W activate [%W identify %x %y]
}
bind Scrollbar <Motion> {
%W activate [%W identify %x %y]
}
# The "info exists" command in the following binding handles the
# situation where a Leave event occurs for a scrollbar without the Enter
# event. This seems to happen on some systems (such as Solaris 2.4) for
# unknown reasons.
bind Scrollbar <Leave> {
if {$tk_strictMotif && [info exists tk::Priv(activeBg)]} {
%W configure -activebackground $tk::Priv(activeBg)
}
%W activate {}
}
bind Scrollbar <1> {
tk::ScrollButtonDown %W %x %y
}
bind Scrollbar <B1-Motion> {
tk::ScrollDrag %W %x %y
}
bind Scrollbar <B1-B2-Motion> {
tk::ScrollDrag %W %x %y
}
bind Scrollbar <ButtonRelease-1> {
tk::ScrollButtonUp %W %x %y
}
bind Scrollbar <B1-Leave> {
# Prevents <Leave> binding from being invoked.
}
bind Scrollbar <B1-Enter> {
# Prevents <Enter> binding from being invoked.
}
bind Scrollbar <2> {
tk::ScrollButton2Down %W %x %y
}
bind Scrollbar <B1-2> {
# Do nothing, since button 1 is already down.
}
bind Scrollbar <B2-1> {
# Do nothing, since button 2 is already down.
}
bind Scrollbar <B2-Motion> {
tk::ScrollDrag %W %x %y
}
bind Scrollbar <ButtonRelease-2> {
tk::ScrollButtonUp %W %x %y
}
bind Scrollbar <B1-ButtonRelease-2> {
# Do nothing: B1 release will handle it.
}
bind Scrollbar <B2-ButtonRelease-1> {
# Do nothing: B2 release will handle it.
}
bind Scrollbar <B2-Leave> {
# Prevents <Leave> binding from being invoked.
}
bind Scrollbar <B2-Enter> {
# Prevents <Enter> binding from being invoked.
}
bind Scrollbar <Control-1> {
tk::ScrollTopBottom %W %x %y
}
bind Scrollbar <Control-2> {
tk::ScrollTopBottom %W %x %y
}
bind Scrollbar <Up> {
tk::ScrollByUnits %W v -1
}
bind Scrollbar <Down> {
tk::ScrollByUnits %W v 1
}
bind Scrollbar <Control-Up> {
tk::ScrollByPages %W v -1
}
bind Scrollbar <Control-Down> {
tk::ScrollByPages %W v 1
}
bind Scrollbar <Left> {
tk::ScrollByUnits %W h -1
}
bind Scrollbar <Right> {
tk::ScrollByUnits %W h 1
}
bind Scrollbar <Control-Left> {
tk::ScrollByPages %W h -1
}
bind Scrollbar <Control-Right> {
tk::ScrollByPages %W h 1
}
bind Scrollbar <Prior> {
tk::ScrollByPages %W hv -1
}
bind Scrollbar <Next> {
tk::ScrollByPages %W hv 1
}
bind Scrollbar <Home> {
tk::ScrollToPos %W 0
}
bind Scrollbar <End> {
tk::ScrollToPos %W 1
}
}
if {[tk windowingsystem] eq "aqua"} {
bind Scrollbar <MouseWheel> {
tk::ScrollByUnits %W v [expr {- (%D)}]
}
bind Scrollbar <Option-MouseWheel> {
tk::ScrollByUnits %W v [expr {-10 * (%D)}]
}
bind Scrollbar <Shift-MouseWheel> {
tk::ScrollByUnits %W h [expr {- (%D)}]
}
bind Scrollbar <Shift-Option-MouseWheel> {
tk::ScrollByUnits %W h [expr {-10 * (%D)}]
}
}
# tk::ScrollButtonDown --
# This procedure is invoked when a button is pressed in a scrollbar.
# It changes the way the scrollbar is displayed and takes actions
# depending on where the mouse is.
#
# Arguments:
# w - The scrollbar widget.
# x, y - Mouse coordinates.
proc tk::ScrollButtonDown {w x y} {
variable ::tk::Priv
set Priv(relief) [$w cget -activerelief]
$w configure -activerelief sunken
set element [$w identify $x $y]
if {$element eq "slider"} {
ScrollStartDrag $w $x $y
} else {
ScrollSelect $w $element initial
}
}
# ::tk::ScrollButtonUp --
# This procedure is invoked when a button is released in a scrollbar.
# It cancels scans and auto-repeats that were in progress, and restores
# the way the active element is displayed.
#
# Arguments:
# w - The scrollbar widget.
# x, y - Mouse coordinates.
proc ::tk::ScrollButtonUp {w x y} {
variable ::tk::Priv
tk::CancelRepeat
if {[info exists Priv(relief)]} {
# Avoid error due to spurious release events
$w configure -activerelief $Priv(relief)
ScrollEndDrag $w $x $y
$w activate [$w identify $x $y]
}
}
# ::tk::ScrollSelect --
# This procedure is invoked when a button is pressed over the scrollbar.
# It invokes one of several scrolling actions depending on where in
# the scrollbar the button was pressed.
#
# Arguments:
# w - The scrollbar widget.
# element - The element of the scrollbar that was selected, such
# as "arrow1" or "trough2". Shouldn't be "slider".
# repeat - Whether and how to auto-repeat the action: "noRepeat"
# means don't auto-repeat, "initial" means this is the
# first action in an auto-repeat sequence, and "again"
# means this is the second repetition or later.
proc ::tk::ScrollSelect {w element repeat} {
variable ::tk::Priv
if {![winfo exists $w]} return
switch -- $element {
"arrow1" {ScrollByUnits $w hv -1}
"trough1" {ScrollByPages $w hv -1}
"trough2" {ScrollByPages $w hv 1}
"arrow2" {ScrollByUnits $w hv 1}
default {return}
}
if {$repeat eq "again"} {
set Priv(afterId) [after [$w cget -repeatinterval] \
[list tk::ScrollSelect $w $element again]]
} elseif {$repeat eq "initial"} {
set delay [$w cget -repeatdelay]
if {$delay > 0} {
set Priv(afterId) [after $delay \
[list tk::ScrollSelect $w $element again]]
}
}
}
# ::tk::ScrollStartDrag --
# This procedure is called to initiate a drag of the slider. It just
# remembers the starting position of the mouse and slider.
#
# Arguments:
# w - The scrollbar widget.
# x, y - The mouse position at the start of the drag operation.
proc ::tk::ScrollStartDrag {w x y} {
variable ::tk::Priv
if {[$w cget -command] eq ""} {
return
}
set Priv(pressX) $x
set Priv(pressY) $y
set Priv(initValues) [$w get]
set iv0 [lindex $Priv(initValues) 0]
if {[llength $Priv(initValues)] == 2} {
set Priv(initPos) $iv0
} elseif {$iv0 == 0} {
set Priv(initPos) 0.0
} else {
set Priv(initPos) [expr {(double([lindex $Priv(initValues) 2])) \
/ [lindex $Priv(initValues) 0]}]
}
}
# ::tk::ScrollDrag --
# This procedure is called for each mouse motion even when the slider
# is being dragged. It notifies the associated widget if we're not
# jump scrolling, and it just updates the scrollbar if we are jump
# scrolling.
#
# Arguments:
# w - The scrollbar widget.
# x, y - The current mouse position.
proc ::tk::ScrollDrag {w x y} {
variable ::tk::Priv
if {$Priv(initPos) eq ""} {
return
}
set delta [$w delta [expr {$x - $Priv(pressX)}] [expr {$y - $Priv(pressY)}]]
if {[$w cget -jump]} {
if {[llength $Priv(initValues)] == 2} {
$w set [expr {[lindex $Priv(initValues) 0] + $delta}] \
[expr {[lindex $Priv(initValues) 1] + $delta}]
} else {
set delta [expr {round($delta * [lindex $Priv(initValues) 0])}]
eval [list $w] set [lreplace $Priv(initValues) 2 3 \
[expr {[lindex $Priv(initValues) 2] + $delta}] \
[expr {[lindex $Priv(initValues) 3] + $delta}]]
}
} else {
ScrollToPos $w [expr {$Priv(initPos) + $delta}]
}
}
# ::tk::ScrollEndDrag --
# This procedure is called to end an interactive drag of the slider.
# It scrolls the window if we're in jump mode, otherwise it does nothing.
#
# Arguments:
# w - The scrollbar widget.
# x, y - The mouse position at the end of the drag operation.
proc ::tk::ScrollEndDrag {w x y} {
variable ::tk::Priv
if {$Priv(initPos) eq ""} {
return
}
if {[$w cget -jump]} {
set delta [$w delta [expr {$x - $Priv(pressX)}] \
[expr {$y - $Priv(pressY)}]]
ScrollToPos $w [expr {$Priv(initPos) + $delta}]
}
set Priv(initPos) ""
}
# ::tk::ScrollByUnits --
# This procedure tells the scrollbar's associated widget to scroll up
# or down by a given number of units. It notifies the associated widget
# in different ways for old and new command syntaxes.
#
# Arguments:
# w - The scrollbar widget.
# orient - Which kinds of scrollbars this applies to: "h" for
# horizontal, "v" for vertical, "hv" for both.
# amount - How many units to scroll: typically 1 or -1.
proc ::tk::ScrollByUnits {w orient amount} {
set cmd [$w cget -command]
if {$cmd eq "" || ([string first \
[string index [$w cget -orient] 0] $orient] < 0)} {
return
}
set info [$w get]
if {[llength $info] == 2} {
uplevel #0 $cmd scroll $amount units
} else {
uplevel #0 $cmd [expr {[lindex $info 2] + $amount}]
}
}
# ::tk::ScrollByPages --
# This procedure tells the scrollbar's associated widget to scroll up
# or down by a given number of screenfuls. It notifies the associated
# widget in different ways for old and new command syntaxes.
#
# Arguments:
# w - The scrollbar widget.
# orient - Which kinds of scrollbars this applies to: "h" for
# horizontal, "v" for vertical, "hv" for both.
# amount - How many screens to scroll: typically 1 or -1.
proc ::tk::ScrollByPages {w orient amount} {
set cmd [$w cget -command]
if {$cmd eq "" || ([string first \
[string index [$w cget -orient] 0] $orient] < 0)} {
return
}
set info [$w get]
if {[llength $info] == 2} {
uplevel #0 $cmd scroll $amount pages
} else {
uplevel #0 $cmd [expr {[lindex $info 2] + $amount*([lindex $info 1] - 1)}]
}
}
# ::tk::ScrollToPos --
# This procedure tells the scrollbar's associated widget to scroll to
# a particular location, given by a fraction between 0 and 1. It notifies
# the associated widget in different ways for old and new command syntaxes.
#
# Arguments:
# w - The scrollbar widget.
# pos - A fraction between 0 and 1 indicating a desired position
# in the document.
proc ::tk::ScrollToPos {w pos} {
set cmd [$w cget -command]
if {$cmd eq ""} {
return
}
set info [$w get]
if {[llength $info] == 2} {
uplevel #0 $cmd moveto $pos
} else {
uplevel #0 $cmd [expr {round([lindex $info 0]*$pos)}]
}
}
# ::tk::ScrollTopBottom
# Scroll to the top or bottom of the document, depending on the mouse
# position.
#
# Arguments:
# w - The scrollbar widget.
# x, y - Mouse coordinates within the widget.
proc ::tk::ScrollTopBottom {w x y} {
variable ::tk::Priv
set element [$w identify $x $y]
if {[string match *1 $element]} {
ScrollToPos $w 0
} elseif {[string match *2 $element]} {
ScrollToPos $w 1
}
# Set Priv(relief), since it's needed by tk::ScrollButtonUp.
set Priv(relief) [$w cget -activerelief]
}
# ::tk::ScrollButton2Down
# This procedure is invoked when button 2 is pressed over a scrollbar.
# If the button is over the trough or slider, it sets the scrollbar to
# the mouse position and starts a slider drag. Otherwise it just
# behaves the same as button 1.
#
# Arguments:
# w - The scrollbar widget.
# x, y - Mouse coordinates within the widget.
proc ::tk::ScrollButton2Down {w x y} {
variable ::tk::Priv
set element [$w identify $x $y]
if {[string match {arrow[12]} $element]} {
ScrollButtonDown $w $x $y
return
}
ScrollToPos $w [$w fraction $x $y]
set Priv(relief) [$w cget -activerelief]
# Need the "update idletasks" below so that the widget calls us
# back to reset the actual scrollbar position before we start the
# slider drag.
update idletasks
$w configure -activerelief sunken
$w activate slider
ScrollStartDrag $w $x $y
}
Mini Shell