#!/usr/bin/env tclsh
 #
 # remember.tcl --
 #
 # This file implements a simple Tk program that remembers its window position,
 # size, and state.  It saves this information to remember.ini when it closes
 # and loads it again when started.
 #
 # Copyright (c) 2005 Michael Leonhard
 #
 # This file is placed in the public domain.
 # IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT, INDIRECT, 
 # SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OF THIS
 # SOFTWARE, OR ANY DERIVATIVES THEREOF, EVEN IF THE AUTHOR HAS BEEN ADVISED OF
 # THE POSSIBILITY OF SUCH DAMAGE.
 #
 # THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT LIMITED
 # TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 # PURPOSE, AND NON-INFRINGEMENT.  THIS SOFTWARE IS PROVIDED ON AN "AS IS"
 # BASIS, AND THE AUTHOR HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT,
 # UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 
 package require Tk
 
 namespace eval rememberini {
     namespace export sourceIni
     namespace export writeIni
     
     set INIFILE "remember.ini"
     
     # rememberini::sourceIni --
     #
     # Sets default variable values and sources the remember.ini file.
     # Informs user if sourcing fails.  Ignores missing ini file.
     #
     # Expected variables:
     #    WindowGeom = WxH+X+Y where W=width, H=height, position=(X,Y)
     #    WindowState = normal | maximized | minimized
     proc sourceIni {} {
         variable INIFILE
         # defaults
         variable WindowGeom 500x400+100+100
         variable WindowState normal
         
         # check that the file is readable
         if { ![file readable $INIFILE]} { # no inifile, use defaults
             puts "ini file not found, using defaults"
             return
         }
         
         # try to source, giving a popup if there was an error
         # (so the user knows why his settings vanished)
         if { [catch {source $INIFILE}] } {
             tk_messageBox -title "Error" -type ok -icon error -message \
                 [join [list \
                     "Settings cannot be loaded.\n" \
                     "The file \"$INIFILE\" is corrupt.\n" \
                     "Using default settings."] ""]
             return
         }
     }
     
     # rememberini::sourceIni --
     #
     # Write the variables to the remember.ini as a Tcl script.
     proc writeIni {} {
         variable INIFILE
         variable WindowGeom
         variable WindowState
         
         # open the file for writing (truncates if file exists)
         if { [catch {set fc [open $INIFILE w]}] } {
             tk_messageBox -title "Error" -type ok -icon error -message \
                 "Unable to save settings to \"$INIFILE\"."
             return
         }
         
         # write file
         puts $fc "# remember.ini - settings for Remember"
         puts $fc "# This file is generated automatically when Remember closes."
         puts $fc "# Do not edit this file! Incorrect entries will crash the program."
         puts $fc [list set WindowGeom $WindowGeom]
         puts $fc [list set WindowState $WindowState]
         
         close $fc
     }
 }
 
 namespace eval remember {
     namespace export start_program
     
     # remember::unmapEvent --
     #
     # Handles <Unmap> event which occurs when the main window is minimized.
     # Saves window state.
     proc unmapEvent w {
         # do nothing if event is not for main window
         if { $w ne "." } {
             return
         }
         # window is minimized (hidden)
         variable WindowState minimized
         puts "MainState := minimized (hidden)"
         bell
         }
     
     # remember::configureEvent --
     #
     # Handles <Configure> event which occurs when window is reposition, 
     # resized, iconified, or maximized.  Saves new position if window is not
     # minimized or maximized.  Saves window state.
     proc configureEvent { w x y height width } {
         # do nothing if event is not for main window
         if { $w ne "." } {
             return
         }
         
         # window is iconified
         if { [wm state $w] eq "iconic" } {
             variable WindowState minimized
             puts "WindowState := minimized (iconic)"
             bell
             return
         }
         # window is maximized (Windows only)
         if { [wm state $w] eq "zoomed" } {
             variable WindowState maximized
             puts "WindowState := maximized"
             bell
             return
         }
         # window has been moved/resized
         if { [wm state $w] eq "normal" } {
             variable WindowState normal
             variable WindowGeom [join [list $width x $height + $x + $y] ""]
             puts "WindowState := normal, geom:=$WindowGeom"
             return
         }
         # execution should never reach here
         puts "unknown window state [wm state .]"
     }
     
     proc makeWindow {} {
         set w .
         
         # Set window geometry and maximize/minimized state
         variable WindowState
         variable WindowGeom
         if { $WindowState eq "minimized" } { wm iconify $w}
         wm geometry $w $WindowGeom
         if { $WindowState eq "maximized" } { wm state $w zoomed}
         
         wm title $w "Remember"
         wm iconname $w "Remember"
         
         # event bindings
         bind . <Configure> "remember::configureEvent %W %x %y %h %w"
         bind . <Unmap> "remember::unmapEvent %W"
         wm protocol $w WM_DELETE_WINDOW "remember::close_program $w"
         
         # window contents (label)
         label .message -text [join [list \
             "Remember - a Tcl/Tk program that remembers\n" \
             "its window position, size, and state."] ""]
         pack .message -expand yes -fill both
     }
     
     proc start_program {} {
         # read ini file and set variables in the remember namespace
         rememberini::sourceIni
         variable WindowState $rememberini::WindowState
         variable WindowGeom $rememberini::WindowGeom
         
         makeWindow
     }
     
     proc close_program { w } {
         # set variables in rememberini namespace and write ini file
         variable WindowGeom
         variable WindowState
         set rememberini::WindowGeom $WindowGeom
         set rememberini::WindowState $WindowState
         rememberini::writeIni
         
         destroy $w
     }
 }
 
 remember::start_program