# entry.tcl --
#
# This file defines the default bindings for Tk entry widgets.
#
# @(#) entry.tcl 1.29 95/03/07 22:52:27
#
# Copyright (c) 1992-1994 The Regents of the University of California.
# Copyright (c) 1994-1995 Sun Microsystems, Inc.
#
# See the file "license.terms" for information on usage and redistribution
# of this file, and for a DISCLAIMER OF ALL WARRANTIES.
#

#-------------------------------------------------------------------------
# Elements of tkPriv that are used in this file:
#
# afterId -		If non-null, it means that auto-scanning is underway
#			and it gives the "after" id for the next auto-scan
#			command to be executed.
# mouseMoved -		Non-zero means the mouse has moved a significant
#			amount since the button went down (so, for example,
#			start dragging out a selection).
# pressX -		X-coordinate at which the mouse button was pressed.
# selectMode -		The style of selection currently underway:
#			char, word, or line.
# x, y -		Last known mouse coordinates for scanning
#			and auto-scanning.
#-------------------------------------------------------------------------

# tkEntryBind --
# This procedure is invoked the first time the mouse enters an
# entry widget or an entry widget receives the input focus.  It creates
# all of the class bindings for entries.
#
# Arguments:
# event -	Indicates which event caused the procedure to be invoked
#		(Enter or FocusIn).  It is used so that we can carry out
#		the functions of that event in addition to setting up
#		bindings.

proc tkEntryBind event {
    global tk_strictMotif

    bind Entry <Enter> {}
    bind Entry <FocusIn> {}

    # Standard Motif bindings:

    bind Entry <1> {
	tkEntryButton1 %W %x
	%W selection clear
    }
    bind Entry <B1-Motion> {
	set tkPriv(x) %x
	tkEntryMouseSelect %W %x
    }
    bind Entry <Double-1> {
	set tkPriv(selectMode) word
	tkEntryMouseSelect %W %x
	catch {%W icursor sel.first}
    }
    bind Entry <Triple-1> {
	set tkPriv(selectMode) line
	tkEntryMouseSelect %W %x
	%W icursor 0
    }
    bind Entry <Shift-1> {
	set tkPriv(selectMode) char
	%W selection adjust @%x
    }
    bind Entry <Double-Shift-1>	{
	set tkPriv(selectMode) word
	tkEntryMouseSelect %W %x
    }
    bind Entry <Triple-Shift-1>	{
	set tkPriv(selectMode) line
	tkEntryMouseSelect %W %x
    }
    bind Entry <B1-Leave> {
	set tkPriv(x) %x
	tkEntryAutoScan %W
    }
    bind Entry <B1-Enter> {
	tkCancelRepeat
    }
    bind Entry <ButtonRelease-1> {
	tkCancelRepeat
    }
    bind Entry <Control-1> {
	%W icursor @%x
    }

    bind Entry <Left> {
	tkEntrySetCursor %W [expr [%W index insert] - 1]
    }
    bind Entry <Right> {
	tkEntrySetCursor %W [expr [%W index insert] + 1]
    }
    bind Entry <Shift-Left> {
	tkEntryKeySelect %W [expr [%W index insert] - 1]
	tkEntrySeeInsert %W
    }
    bind Entry <Shift-Right> {
	tkEntryKeySelect %W [expr [%W index insert] + 1]
	tkEntrySeeInsert %W
    }
    bind Entry <Control-Left> {
	tkEntrySetCursor %W \
		[string wordstart [%W get] [expr [%W index insert] - 1]]
    }
    bind Entry <Control-Right> {
	tkEntrySetCursor %W [string wordend [%W get] [%W index insert]]
    }
    bind Entry <Shift-Control-Left> {
	tkEntryKeySelect %W \
		[string wordstart [%W get] [expr [%W index insert] - 1]]
	tkEntrySeeInsert %W
    }
    bind Entry <Shift-Control-Right> {
	tkEntryKeySelect %W [string wordend [%W get] [%W index insert]]
	tkEntrySeeInsert %W
    }
    bind Entry <Home> {
	tkEntrySetCursor %W 0
    }
    bind Entry <Shift-Home> {
	tkEntryKeySelect %W 0
	tkEntrySeeInsert %W
    }
    bind Entry <End> {
	tkEntrySetCursor %W end
    }
    bind Entry <Shift-End> {
	tkEntryKeySelect %W end
	tkEntrySeeInsert %W
    }

    bind Entry <Delete> {
	if [%W selection present] {
	    %W delete sel.first sel.last
	} else {
	    %W delete insert
	}
    }
    bind Entry <BackSpace> {
	tkEntryBackspace %W
    }

    bind Entry <Control-space> {
	%W selection from insert
    }
    bind Entry <Select> {
	%W selection from insert
    }
    bind Entry <Control-Shift-space> {
	%W selection adjust insert
    }
    bind Entry <Shift-Select> {
	%W selection adjust insert
    }
    bind Entry <Control-slash> {
	%W selection range 0 end
    }
    bind Entry <Control-backslash> {
	%W selection clear
    }
    tkEntryClipboardKeysyms F16 F20 F18

    bind Entry <KeyPress> {
	tkEntryInsert %W %A
    }

    # Ignore all Alt, Meta, and Control keypresses unless explicitly bound.
    # Otherwise, if a widget binding for one of these is defined, the
    # <KeyPress> class binding will also fire and insert the character,
    # which is wrong.  Ditto for Escape, Return, and Tab.

    bind Entry <Alt-KeyPress> {# nothing}
    bind Entry <Meta-KeyPress> {# nothing}
    bind Entry <Control-KeyPress> {# nothing}
    bind Entry <Escape> {# nothing}
    bind Entry <Return> {# nothing}
    bind Entry <Tab> {# nothing}

    bind Entry <Insert> {
	catch {tkEntryInsert %W [selection get -displayof %W]}
    }

    # Additional emacs-like bindings:

    if !$tk_strictMotif {
	bind Entry <Control-a> {
	    tkEntrySetCursor %W 0
	}
	bind Entry <Control-b> {
	    tkEntrySetCursor %W [expr [%W index insert] - 1]
	}
	bind Entry <Control-d> {
	    %W delete insert
	}
	bind Entry <Control-e> {
	    tkEntrySetCursor %W end
	}
	bind Entry <Control-f> {
	    tkEntrySetCursor %W [expr [%W index insert] + 1]
	}
	bind Entry <Control-h> {
	    tkEntryBackspace %W
	}
	bind Entry <Control-k> {
	    %W delete insert end
	}
	bind Entry <Control-t> {
	    tkEntryTranspose %W
	}
	bind Entry <Meta-b> {
	    tkEntrySetCursor %W \
		    [string wordstart [%W get] [expr [%W index insert] - 1]]
	}
	bind Entry <Meta-d> {
	    %W delete insert [string wordend [%W get] [%W index insert]]
	}
	bind Entry <Meta-f> {
	    tkEntrySetCursor %W [string wordend [%W get] [%W index insert]]
	}
	bind Entry <Meta-BackSpace> {
	    %W delete [string wordstart [%W get] [expr [%W index insert] - 1]] \
		    insert
	}
	tkEntryClipboardKeysyms Meta-w Control-w Control-y
    
	# A few additional bindings of my own.
    
	bind Entry <Control-v> {
	    catch {
		%W insert insert [selection get -displayof %W]
		tkEntrySeeInsert %W
	    }
	}
	bind Entry <Control-w> {
	    %W delete [string wordstart [%W get] [expr [%W index insert] - 1]] \
		    insert
	}
	bind Entry <2> {
	    %W scan mark %x
	    set tkPriv(x) %x
	    set tkPriv(y) %y
	    set tkPriv(mouseMoved) 0
	}
	bind Entry <B2-Motion> {
	    if {abs(%x-$tkPriv(x)) > 2} {
		set tkPriv(mouseMoved) 1
	    }
	    %W scan dragto %x
	}
	bind Entry <ButtonRelease-2> {
	    if !$tkPriv(mouseMoved) {
		catch {
		    %W insert insert [selection get -displayof %W]
		    tkEntrySeeInsert %W
		}
	    }
	}
    }
    rename tkEntryBind {}
}

# tkEntryClipboardKeysyms --
# This procedure is invoked to identify the keys that correspond to
# the "copy", "cut", and "paste" functions for the clipboard.
#
# Arguments:
# copy -	Name of the key (keysym name plus modifiers, if any,
#		such as "Meta-y") used for the copy operation.
# cut -		Name of the key used for the cut operation.
# paste -	Name of the key used for the paste operation.

proc tkEntryClipboardKeysyms {copy cut paste} {
    bind Entry <$copy> {
	if {[selection own -displayof %W] == "%W"} {
	    clipboard clear -displayof %W
	    clipboard append -displayof %W [selection get -displayof %W]
	}
    }
    bind Entry <$cut> {
	if {[selection own -displayof %W] == "%W"} {
	    clipboard clear -displayof %W
	    clipboard append -displayof %W [selection get -displayof %W]
	    %W delete sel.first sel.last
	}
    }
    bind Entry <$paste> {
	catch {
	    %W insert insert [selection get -displayof %W \
		    -selection CLIPBOARD]
	}
    }
}

# tkEntryButton1 --
# This procedure is invoked to handle button-1 presses in entry
# widgets.  It moves the insertion cursor, sets the selection anchor,
# and claims the input focus.
#
# Arguments:
# w -		The entry window in which the button was pressed.
# x -		The x-coordinate of the button press.

proc tkEntryButton1 {w x} {
    global tkPriv

    set tkPriv(selectMode) char
    set tkPriv(mouseMoved) 0
    set tkPriv(pressX) $x
    $w icursor @$x
    $w selection from @$x
    if {[lindex [$w configure -state] 4] == "normal"} {focus $w}
}

# tkEntryMouseSelect --
# This procedure is invoked when dragging out a selection with
# the mouse.  Depending on the selection mode (character, word,
# line) it selects in different-sized units.  This procedure
# ignores mouse motions initially until the mouse has moved from
# one character to another or until there have been multiple clicks.
#
# Arguments:
# w -		The entry window in which the button was pressed.
# x -		The x-coordinate of the mouse.

proc tkEntryMouseSelect {w x} {
    global tkPriv

    set cur [$w index @$x]
    set anchor [$w index anchor]
    if {($cur != $anchor) || (abs($tkPriv(pressX) - $x) >= 3)} {
	set tkPriv(mouseMoved) 1
    }
    switch $tkPriv(selectMode) {
	char {
	    if $tkPriv(mouseMoved) {
		if {$cur < [$w index anchor]} {
		    $w selection to $cur
		} else {
		    $w selection to [expr $cur+1]
		}
	    }
	}
	word {
	    if {$cur < [$w index anchor]} {
		$w selection range [string wordstart [$w get] $cur] \
			[string wordend [$w get] [expr $anchor-1]]
	    } else {
		$w selection range [string wordstart [$w get] $anchor] \
			[string wordend [$w get] $cur]
	    }
	}
	line {
	    $w selection range 0 end
	}
    }
    update idletasks
}

# tkEntryAutoScan --
# This procedure is invoked when the mouse leaves an entry window
# with button 1 down.  It scrolls the window left or right,
# depending on where the mouse is, and reschedules itself as an
# "after" command so that the window continues to scroll until the
# mouse moves back into the window or the mouse button is released.
#
# Arguments:
# w -		The entry window.

proc tkEntryAutoScan {w} {
    global tkPriv
    set x $tkPriv(x)
    if {$x >= [winfo width $w]} {
	$w xview scroll 2 units
	tkEntryMouseSelect $w $x
    } elseif {$x < 0} {
	$w xview scroll -2 units
	tkEntryMouseSelect $w $x
    }
    set tkPriv(afterId) [after 50 tkEntryAutoScan $w]
}

# tkEntryKeySelect --
# This procedure is invoked when stroking out selections using the
# keyboard.  It moves the cursor to a new position, then extends
# the selection to that position.
#
# Arguments:
# w -		The entry window.
# new -		A new position for the insertion cursor (the cursor hasn't
#		actually been moved to this position yet).

proc tkEntryKeySelect {w new} {
    if ![$w selection present] {
	$w selection from insert
	$w selection to $new
    } else {
	$w selection adjust $new
    }
    $w icursor $new
}

# tkEntryInsert --
# Insert a string into an entry at the point of the insertion cursor.
# If there is a selection in the entry, and it covers the point of the
# insertion cursor, then delete the selection before inserting.
#
# Arguments:
# w -		The entry window in which to insert the string
# s -		The string to insert (usually just a single character)

proc tkEntryInsert {w s} {
    if {$s == ""} {
	return
    }
    catch {
	set insert [$w index insert]
	if {([$w index sel.first] <= $insert)
		&& ([$w index sel.last] >= $insert)} {
	    $w delete sel.first sel.last
	}
    }
    $w insert insert $s
    tkEntrySeeInsert $w
}

# tkEntryBackspace --
# Backspace over the character just before the insertion cursor.
#
# Arguments:
# w -		The entry window in which to backspace.

proc tkEntryBackspace w {
    if [$w selection present] {
	$w delete sel.first sel.last
    } else {
	set x [expr {[$w index insert] - 1}]
	if {$x >= 0} {$w delete $x}
    }
}

# tkEntrySeeInsert --
# Make sure that the insertion cursor is visible in the entry window.
# If not, adjust the view so that it is.
#
# Arguments:
# w -		The entry window.

proc tkEntrySeeInsert w {
    set c [$w index insert]
    set left [$w index @0]
    if {$left > $c} {
	$w xview $c
	return
    }
    set x [winfo width $w]
    while {([$w index @$x] <= $c) && ($left < $c)} {
	incr left
	$w xview $left
    }
}

# tkEntrySetCursor -
# Move the insertion cursor to a given position in an entry.  Also
# clears the selection, if there is one in the entry, and makes sure
# that the insertion cursor is visible.
#
# Arguments:
# w -		The entry window.
# pos -		The desired new position for the cursor in the window.

proc tkEntrySetCursor {w pos} {
    $w icursor $pos
    $w selection clear
    tkEntrySeeInsert $w
}

# tkEntryTranspose -
# This procedure implements the "transpose" function for entry widgets.
# It tranposes the characters on either side of the insertion cursor,
# unless the cursor is at the end of the line.  In this case it
# transposes the two characters to the left of the cursor.  In either
# case, the cursor ends up to the right of the transposed characters.
#
# Arguments:
# w -		The entry window.

proc tkEntryTranspose w {
    set i [$w index insert]
    if {$i < [$w index end]} {
	incr i
    }
    set first [expr $i-2]
    if {$first < 0} {
	return
    }
    set new [string index [$w get] [expr $i-1]][string index [$w get] $first]
    $w delete $first $i
    $w insert insert $new
    tkEntrySeeInsert $w
}
