Прога / tina-2.5.2 / tcl / lib / tk8.3 / scrlbar

# scrlbar.tcl --
#
# This file defines the default bindings for Tk scrollbar widgets.
# It also provides procedures that help in implementing the bindings.
#
# RCS: @(#) $Id: scrlbar.tcl,v 1.8 2000/01/06 02:22:24 hobbs Exp $
#
# 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 {[string compare $tcl_platform(platform) "windows"] && \
[string compare $tcl_platform(platform) "macintosh"]} {

bind Scrollbar <Enter> {
if {$tk_strictMotif} {
set tkPriv(activeBg) [%W cget -activebackground]
%W config -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 tkPriv(activeBg)]} {
%W config -activebackground $tkPriv(activeBg)
}
%W activate {}
}
bind Scrollbar <1> {
tkScrollButtonDown %W %x %y
}
bind Scrollbar <B1-Motion> {
tkScrollDrag %W %x %y
}
bind Scrollbar <B1-B2-Motion> {
tkScrollDrag %W %x %y
}
bind Scrollbar <ButtonRelease-1> {
tkScrollButtonUp %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> {
tkScrollButton2Down %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> {
tkScrollDrag %W %x %y
}
bind Scrollbar <ButtonRelease-2> {
tkScrollButtonUp %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> {
tkScrollTopBottom %W %x %y
}
bind Scrollbar <Control-2> {
tkScrollTopBottom %W %x %y
}

bind Scrollbar <Up> {
tkScrollByUnits %W v -1
}
bind Scrollbar <Down> {
tkScrollByUnits %W v 1
}
bind Scrollbar <Control-Up> {
tkScrollByPages %W v -1
}
bind Scrollbar <Control-Down> {
tkScrollByPages %W v 1
}
bind Scrollbar <Left> {
tkScrollByUnits %W h -1
}
bind Scrollbar <Right> {
tkScrollByUnits %W h 1
}
bind Scrollbar <Control-Left> {
tkScrollByPages %W h -1
}
bind Scrollbar <Control-Right> {
tkScrollByPages %W h 1
}
bind Scrollbar <Prior> {
tkScrollByPages %W hv -1
}
bind Scrollbar <Next> {
tkScrollByPages %W hv 1
}
bind Scrollbar <Home> {
tkScrollToPos %W 0
}
bind Scrollbar <End> {
tkScrollToPos %W 1
}
}
# tkScrollButtonDown --
# 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 tkScrollButtonDown {w x y} {
global tkPriv
set tkPriv(relief) [$w cget -activerelief]
$w configure -activerelief sunken
set element [$w identify $x $y]
if {[string equal $element "slider"]} {
tkScrollStartDrag $w $x $y
} else {
tkScrollSelect $w $element initial
}
}

# tkScrollButtonUp --
# 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 tkScrollButtonUp {w x y} {
global tkPriv
tkCancelRepeat
if {[info exists tkPriv(relief)]} {
# Avoid error due to spurious release events
$w configure -activerelief $tkPriv(relief)
tkScrollEndDrag $w $x $y
$w activate [$w identify $x $y]
}
}

# tkScrollSelect --
# 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 tkScrollSelect {w element repeat} {
global tkPriv
if {![winfo exists $w]} return
switch -- $element {
"arrow1" {tkScrollByUnits $w hv -1}
"trough1" {tkScrollByPages $w hv -1}
"trough2" {tkScrollByPages $w hv 1}
"arrow2" {tkScrollByUnits $w hv 1}
default {return}
}
if {[string equal $repeat "again"]} {
set tkPriv(afterId) [after [$w cget -repeatinterval] \
[list tkScrollSelect $w $element again]]
} elseif {[string equal $repeat "initial"]} {
set delay [$w cget -repeatdelay]
if {$delay > 0} {
set tkPriv(afterId) [after $delay \
[list tkScrollSelect $w $element again]]
}
}
}

# tkScrollStartDrag --
# 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 tkScrollStartDrag {w x y} {
global tkPriv

if {[string equal [$w cget -command] ""]} {
return
}
set tkPriv(pressX) $x
set tkPriv(pressY) $y
set tkPriv(initValues) [$w get]
set iv0 [lindex $tkPriv(initValues) 0]
if {[llength $tkPriv(initValues)] == 2} {
set tkPriv(initPos) $iv0
} elseif {$iv0 == 0} {
set tkPriv(initPos) 0.0
} else {
set tkPriv(initPos) [expr {(double([lindex $tkPriv(initValues) 2])) \
/ [lindex $tkPriv(initValues) 0]}]
}
}

# tkScrollDrag --
# 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 tkScrollDrag {w x y} {
global tkPriv

if {[string equal $tkPriv(initPos) ""]} {
return
}
set delta [$w delta [expr {$x - $tkPriv(pressX)}] [expr {$y - $tkPriv(pressY)}]]
if {[$w cget -jump]} {
if {[llength $tkPriv(initValues)] == 2} {
$w set [expr {[lindex $tkPriv(initValues) 0] + $delta}] \
[expr {[lindex $tkPriv(initValues) 1] + $delta}]
} else {
set delta [expr {round($delta * [lindex $tkPriv(initValues) 0])}]
eval [list $w] set [lreplace $tkPriv(initValues) 2 3 \
[expr {[lindex $tkPriv(initValues) 2] + $delta}] \
[expr {[lindex $tkPriv(initValues) 3] + $delta}]]
}
} else {
tkScrollToPos $w [expr {$tkPriv(initPos) + $delta}]
}
}

# tkScrollEndDrag --
# 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 tkScrollEndDrag {w x y} {
global tkPriv

if {[string equal $tkPriv(initPos) ""]} {
return
}
if {[$w cget -jump]} {
set delta [$w delta [expr {$x - $tkPriv(pressX)}] \
[expr {$y - $tkPriv(pressY)}]]
tkScrollToPos $w [expr {$tkPriv(initPos) + $delta}]
}
set tkPriv(initPos) ""
}

# tkScrollByUnits --
# 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 tkScrollByUnits {w orient amount} {
set cmd [$w cget -command]
if {[string equal $cmd ""] || ([string first \
[string index [$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}]
}
}

# tkScrollByPages --
# 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 tkScrollByPages {w orient amount} {
set cmd [$w cget -command]
if {[string equal $cmd ""] || ([string first \
[string index [$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)}]
}
}

# tkScrollToPos --
# 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 tkScrollToPos {w pos} {
set cmd [$w cget -command]
if {[string equal $cmd ""]} {
return
}
set info [$w get]
if {[llength $info] == 2} {
uplevel #0 $cmd moveto $pos
} else {
uplevel #0 $cmd [expr {round([lindex $info 0]*$pos)}]
}
}

# tkScrollTopBottom
# 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 tkScrollTopBottom {w x y} {
global tkPriv
set element [$w identify $x $y]
if {[string match *1 $element]} {
tkScrollToPos $w 0
} elseif {[string match *2 $element]} {
tkScrollToPos $w 1
}

# Set tkPriv(relief), since it's needed by tkScrollButtonUp.

set tkPriv(relief) [$w cget -activerelief]
}

# tkScrollButton2Down
# 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 tkScrollButton2Down {w x y} {
global tkPriv
set element [$w identify $x $y]
if {[string match {arrow[12]} $element]} {
tkScrollButtonDown $w $x $y
return
}
tkScrollToPos $w [$w fraction $x $y]
set tkPriv(relief) [$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
tkScrollStartDrag $w $x $y
}