combobox.tcl

windows下的GDB insight前端

# Copyright (c) 1998-2003, Bryan Oakley
# All Rights Reservered
#
# Bryan Oakley
# [e-mail]
#
# combobox v2.3 August 16, 2003
#
# a combobox / dropdown listbox (pick your favorite name) widget 
# written in pure tcl
#
# this code is freely distributable without restriction, but is 
# provided as-is with no warranty expressed or implied. 
#
# thanks to the following people who provided beta test support or
# patches to the code (in no particular order):
#
# Scott Beasley     Alexandre Ferrieux      Todd Helfter
# Matt Gushee       Laurent Duperval        John Jackson
# Fred Rapp         Christopher Nelson
# Eric Galluzzo     Jean-Francois Moine	    Oliver Bienert
#
# A special thanks to Martin M. Hunt who provided several good ideas, 
# and always with a patch to implement them. Jean-Francois Moine, 
# Todd Helfter and John Jackson were also kind enough to send in some 
# code patches.
#
# ... and many others over the years.

package require Tk 8.0
package provide combobox 2.3

namespace eval ::combobox {

    # this is the public interface
    namespace export combobox

    # these contain references to available options
    variable widgetOptions

    # these contain references to available commands and subcommands
    variable widgetCommands
    variable scanCommands
    variable listCommands
}

# ::combobox::combobox --
#
#     This is the command that gets exported. It creates a new
#     combobox widget.
#
# Arguments:
#
#     w        path of new widget to create
#     args     additional option/value pairs (eg: -background white, etc.)
#
# Results:
#
#     It creates the widget and sets up all of the default bindings
#
# Returns:
#
#     The name of the newly create widget

proc ::combobox::combobox {w args} {
    variable widgetOptions
    variable widgetCommands
    variable scanCommands
    variable listCommands

    # perform a one time initialization
    if {![info exists widgetOptions]} {
	Init
    }

    # build it...
    eval Build $w $args

    # set some bindings...
    SetBindings $w

    # and we are done!
    return $w
}


# ::combobox::Init --
#
#     Initialize the namespace variables. This should only be called
#     once, immediately prior to creating the first instance of the
#     widget
#
# Arguments:
#
#    none
#
# Results:
#
#     All state variables are set to their default values; all of 
#     the option database entries will exist.
#
# Returns:
# 
#     empty string

proc ::combobox::Init {} {
    variable widgetOptions
    variable widgetCommands
    variable scanCommands
    variable listCommands
    variable defaultEntryCursor

    array set widgetOptions [list \
	    -background          {background          Background} \
	    -bd                  -borderwidth \
	    -bg                  -background \
	    -borderwidth         {borderWidth         BorderWidth} \
	    -buttonbackground    {buttonBackground    Background} \
	    -command             {command             Command} \
	    -commandstate        {commandState        State} \
	    -cursor              {cursor              Cursor} \
	    -disabledbackground  {disabledBackground  DisabledBackground} \
	    -disabledforeground  {disabledForeground  DisabledForeground} \
            -dropdownwidth       {dropdownWidth       DropdownWidth} \
	    -editable            {editable            Editable} \
	    -elementborderwidth  {elementBorderWidth  BorderWidth} \
	    -fg                  -foreground \
	    -font                {font                Font} \
	    -foreground          {foreground          Foreground} \
	    -height              {height              Height} \
	    -highlightbackground {highlightBackground HighlightBackground} \
	    -highlightcolor      {highlightColor      HighlightColor} \
	    -highlightthickness  {highlightThickness  HighlightThickness} \
	    -image               {image               Image} \
	    -listvar             {listVariable        Variable} \
	    -maxheight           {maxHeight           Height} \
	    -opencommand         {opencommand         Command} \
	    -relief              {relief              Relief} \
	    -selectbackground    {selectBackground    Foreground} \
	    -selectborderwidth   {selectBorderWidth   BorderWidth} \
	    -selectforeground    {selectForeground    Background} \
	    -state               {state               State} \
	    -takefocus           {takeFocus           TakeFocus} \
	    -textvariable        {textVariable        Variable} \
	    -value               {value               Value} \
	    -width               {width               Width} \
	    -xscrollcommand      {xScrollCommand      ScrollCommand} \
    ]


    set widgetCommands [list \
	    bbox      cget     configure    curselection \
	    delete    get      icursor      index        \
	    insert    list     scan         selection    \
	    xview     select   toggle       open         \
            close     entryset subwidget \
    ]

    set listCommands [list \
	    delete       get      \
            index        insert       size \
    ]

    set scanCommands [list mark dragto]

    # why check for the Tk package? This lets us be sourced into 
    # an interpreter that doesn't have Tk loaded, such as the slave
    # interpreter used by pkg_mkIndex. In theory it should have no
    # side effects when run 
    if {[lsearch -exact [package names] "Tk"] != -1} {

	##################################################################
	#- this initializes the option database. Kinda gross, but it works
	#- (I think). 
	##################################################################

	# the image used for the button...
	if {$::tcl_platform(platform) == "windows"} {
	    image create bitmap ::combobox::bimage -data {
		#define down_arrow_width 12
		#define down_arrow_height 12
		static char down_arrow_bits[] = {
		    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
		    0xfc,0xf1,0xf8,0xf0,0x70,0xf0,0x20,0xf0,
		    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00;
		}
	    }
	} else {
	    image create bitmap ::combobox::bimage -data  {
		#define down_arrow_width 15
		#define down_arrow_height 15
		static char down_arrow_bits[] = {
		    0x00,0x80,0x00,0x80,0x00,0x80,0x00,0x80,
		    0x00,0x80,0xf8,0x8f,0xf0,0x87,0xe0,0x83,
		    0xc0,0x81,0x80,0x80,0x00,0x80,0x00,0x80,
		    0x00,0x80,0x00,0x80,0x00,0x80
		}
	    }
	}

	# compute a widget name we can use to create a temporary widget
	set tmpWidget ".__tmp__"
	set count 0
	while {[winfo exists $tmpWidget] == 1} {
	    set tmpWidget ".__tmp__$count"
	    incr count
	}

	# get the scrollbar width. Because we try to be clever and draw our
	# own button instead of using a tk widget, we need to know what size
	# button to create. This little hack tells us the width of a scroll
	# bar.
	#
	# NB: we need to be sure and pick a window  that doesn't already
	# exist... 
	scrollbar $tmpWidget
	set sb_width [winfo reqwidth $tmpWidget]
	set bbg [$tmpWidget cget -background]
	destroy $tmpWidget

	# steal options from the entry widget
	# we want darn near all options, so we'll go ahead and do
	# them all. No harm done in adding the one or two that we
	# don't use.
	entry $tmpWidget 
	foreach foo [$tmpWidget configure] {
	    # the cursor option is special, so we'll save it in
	    # a special way
	    if {[lindex $foo 0] == "-cursor"} {
		set defaultEntryCursor [lindex $foo 4]
	    }
	    if {[llength $foo] == 5} {
		set option [lindex $foo 1]
		set value [lindex $foo 4]
		option add *Combobox.$option $value widgetDefault

		# these options also apply to the dropdown listbox
		if {[string compare $option "foreground"] == 0 \
			|| [string compare $option "background"] == 0 \
			|| [string compare $option "font"] == 0} {
		    option add *Combobox*ComboboxListbox.$option $value \
			    widgetDefault
		}
	    }
	}
	destroy $tmpWidget

	# these are unique to us...
	option add *Combobox.elementBorderWidth  1	widgetDefault
	option add *Combobox.buttonBackground    $bbg	widgetDefault
	option add *Combobox.dropdownWidth       {}     widgetDefault
	option add *Combobox.openCommand         {}     widgetDefault
	option add *Combobox.cursor              {}     widgetDefault
	option add *Combobox.commandState        normal widgetDefault
	option add *Combobox.editable            1      widgetDefault
	option add *Combobox.maxHeight           10     widgetDefault
	option add *Combobox.height              0
    }

    # set class bindings
    SetClassBindings
}

# ::combobox::SetClassBindings --
#
#    Sets up the default bindings for the widget class
#
#    this proc exists since it's The Right Thing To Do, but
#    I haven't had the time to figure out how to do all the
#    binding stuff on a class level. The main problem is that
#    the entry widget must have focus for the insertion cursor
#    to be visible. So, I either have to have the entry widget
#    have the Combobox bindtag, or do some fancy juggling of
#    events or some such. What a pain.
#
# Arguments:
#
#    none
#
# Returns:
#
#    empty string

proc ::combobox::SetClassBindings {} {

    # make sure we clean up after ourselves...
    bind Combobox <Destroy> [list ::combobox::DestroyHandler %W]

    # this will (hopefully) close (and lose the grab on) the
    # listbox if the user clicks anywhere outside of it. Note
    # that on Windows, you can click on some other app and
    # the listbox will still be there, because tcl won't see
    # that button click
    set this {[::combobox::convert %W -W]}
    bind Combobox <Any-ButtonPress>   "$this close"
    bind Combobox <Any-ButtonRelease> "$this close"

    # this helps (but doesn't fully solve) focus issues. The general
    # idea is, whenever the frame gets focus it gets passed on to
    # the entry widget
    bind Combobox <FocusIn> {::combobox::tkTabToWindow \
				 [::combobox::convert %W -W].entry}

    # this closes the listbox if we get hidden
    bind Combobox <Unmap> {[::combobox::convert %W -W] close}

    return ""
}

# ::combobox::SetBindings --
#
#    here's where we do most of the binding foo. I think there's probably
#    a few bindings I ought to add that I just haven't thought
#    about...
#
#    I'm not convinced these are the proper bindings. Ideally all
#    bindings should be on "Combobox", but because of my juggling of
#    bindtags I'm not convinced thats what I want to do. But, it all
#    seems to work, its just not as robust as it could be.
#
# Arguments:
#
#    w    widget pathname
#
# Returns:
#
#    empty string

proc ::combobox::SetBindings {w} {
    upvar ::combobox::${w}::widgets  widgets
    upvar ::combobox::${w}::options  options

    # juggle the bindtags. The basic idea here is to associate the
    # widget name with the entry widget, so if a user does a bind
    # on the combobox it will get handled properly since it is
    # the entry widget that has keyboard focus.
    bindtags $widgets(entry) \
	    [concat $widgets(this) [bindtags $widgets(entry)]]

    bindtags $widgets(button) \
	    [concat $widgets(this) [bindtags $widgets(button)]]

    # override the default bindings for tab and shift-tab. The
    # focus procs take a widget as their only parameter and we
    # want to make sure the right window gets used (for shift-
    # tab we want it to appear as if the event was generated
    # on the frame rather than the entry. 
    bind $widgets(entry) <Tab> \
	    "::combobox::tkTabToWindow \[tk_focusNext $widgets(entry)\]; break"
    bind $widgets(entry) <Shift-Tab> \
	    "::combobox::tkTabToWindow \[tk_focusPrev $widgets(this)\]; break"
    
    # this makes our "button" (which is actually a label)
    # do the right thing
    bind $widgets(button) <ButtonPress-1> [list $widgets(this) toggle]

    # this lets the autoscan of the listbox work, even if they
    # move the cursor over the entry widget.
    bind $widgets(entry) <B1-Enter> "break"

    bind $widgets(listbox) <ButtonRelease-1> \
        "::combobox::Select [list $widgets(this)] \
         \[$widgets(listbox) nearest %y\]; break"

    bind $widgets(vsb) <ButtonPress-1>   {continue}
    bind $widgets(vsb) <ButtonRelease-1> {continue}

    bind $widgets(listbox) <Any-Motion> {
	%W selection clear 0 end
	%W activate @%x,%y
	%W selection anchor @%x,%y
	%W selection set @%x,%y @%x,%y
	# need to do a yview if the cursor goes off the top
	# or bottom of the window... (or do we?)
    }

    # these events need to be passed from the entry widget
    # to the listbox, or otherwise need some sort of special
    # handling. 
    foreach event [list <Up> <Down> <Tab> <Return> <Escape> \
	    <Next> <Prior> <Double-1> <1> <Any-KeyPress> \
	    <FocusIn> <FocusOut>] {
	bind $widgets(entry) $event \
            [list ::combobox::HandleEvent $widgets(this) $event]
    }

    # like the other events, <MouseWheel> needs to be passed from
    # the entry widget to the listbox. However, in this case we
    # need to add an additional parameter
    catch {
	bind $widgets(entry) <MouseWheel> \
	    [list ::combobox::HandleEvent $widgets(this) <MouseWheel> %D]
    }
}

# ::combobox::Build --
#
#    This does all of the work necessary to create the basic
#    combobox. 
#
# Arguments:
#
#    w        widget name
#    args     additional option/value pairs
#
# Results:
#
#    Creates a new widget with the given name. Also creates a new
#    namespace patterened after the widget name, as a child namespace
#    to ::combobox
#
# Returns:
#
#    the name of the widget

proc ::combobox::Build {w args } {
    variable widgetOptions

    if {[winfo exists $w]} {
	error "window name \"$w\" already exists"
    }

    # create the namespace for this instance, and define a few
    # variables
    namespace eval ::combobox::$w {

	variable ignoreTrace 0
	variable oldFocus    {}
	variable oldGrab     {}
	variable oldValue    {}
	variable options
	variable this
	variable widgets

	set widgets(foo) foo  ;# coerce into an array
	set options(foo) foo  ;# coerce into an array

	unset widgets(foo)
	unset options(foo)
    }