#!/usr/bin/wish -f
# logView.tk  --
#	
#	Essentially a general purpose GUI wrapper to tail, gui and any commands
#	that will output data continuosly. This GUI has the ability to record
#	the commands as smart buttons, so that you can re-run the same commands
#	again and again without having to retype

  
set tailRc "~/.tailrc"
wm title .  "Process Log Viewer"
wm iconname . "Log Viewer"

global tailSize textw fileName tailFd curNick tailOpts statusImgWin

# tailSize --> size in lines of tail output to display
# fileName --> File name: variable
# tailFd   --> proc fd or file fd of current tail process
# curNick  --> current nick being shown; nick essentially a shortcut to a cmd.
# tailOpts --> saved options
# statusImgWin --> window showing what kind of error it is!

set tailSize 20
set fileName "/home/";     #include your own path here

# file types for the file selection dialog box.
set tailOpts(types) {
   {"All files"                 *}
   {"Text files"                {.txt .doc}      }
   {"Text files"                {}           TEXT}

   {"Tcl Scripts"               {.tcl}       TEXT}
   {"C Source Files"            {.c .h}          }
   {"All Source Files"          {.tcl .c .h}     }
   {"Image Files"               {.gif}           }
   {"Image Files"               {.jpeg .jpg}     }
   {"Image Files"               ""    {GIFF JPEG}}
}
set tailOpts(wins) {}

# Next, we will build the user interface. 

proc BuildTailGui {w} {
    global tailSize textw fileName tailFd curNick tailOpts statusImgWin
    global viewOptMenu

    if {$w == "."} {
       set w "";
    }

    # Build Menu for file
    menu $w.menu -tearoff 0

    # File menu
    set m $w.menu.file
    menu $m -tearoff 0
    $w.menu add cascade -label "File" -menu $m -underline 0
    $m add command -label "Add New ..." -command {AddNew} -underline 0
    $m add command -label "Exit" -command {exit} -underline 0

    # Edit Menu
    set m $w.menu.edit
    menu $m -tearoff 0
    $w.menu add cascade -label "Edit" -menu $m -underline 0
    $m add command -label "Delete Nicks.." -command {DeleteNicks} -underline 0

    # Help Menu
    set m $w.menu.help
    menu $m -tearoff 0 
    $w.menu add cascade -label "Help" -menu $m -underline 0
    $m add command -label "About..." -underline 0 -command {
        tk_messageBox -parent . -title "Process Log Viewer" -type \
        ok -message    "Tk Tail Tool \nby Krishna Vedati(kvedati@yahoo.com)"
    } 

# The routine then adds a text widget to display the output of any log proces.


# Next, the routine builds rows of widgets.

    # Create status/error message window
    frame $w.status  -relief sunken -bd 2
    set statusImgWin [label $w.status.flag -bitmap info]
    label $w.status.lab -textvariable statusText -anchor w -bg "wheat"
    pack $w.status.flag -side left  
    pack $w.status.lab -side left -fill both -expand 1

    # File name: entry panel
    frame $w.file
    label $w.file.label -text "File name:" -width 13 -anchor w
    entry $w.file.entry -width 30 -textvariable fileName
    button $w.file.choose -text "..." -command \
        "set fileName \[tk_getOpenFile -filetypes \$tailOpts(types) \
         -parent \[winfo toplevel $w.file\]\];"

    button $w.file.button -text "Tail File" \
       -command "AddToView  file \$fileName"
    pack $w.file.label $w.file.entry -side left
    pack $w.file.choose -side left -pady 5 -padx 10
    pack $w.file.button -side left -pady 5 -padx 10
    bind $w.file.entry <Return> " AddToView  file \$fileName"
    focus $w.file.entry

    # Command entry panel
    frame $w.fileC
    label $w.fileC.cLabel -text "Command:" -width 13 -anchor w
    entry $w.fileC.cEntry -width 40 -textvariable command
    label $w.fileC.nLabel -text "Nick:" -anchor w
    entry $w.fileC.nEntry -width 15 -textvariable nick
    button $w.fileC.add -text "Add" -command "AddToView \"command\"\
         \$command \$nick;"
    pack $w.fileC.cLabel $w.fileC.cEntry -side left
    pack $w.fileC.nLabel -side left -pady 5 -padx 10
    pack $w.fileC.nEntry -side left -pady 5 -padx 5
    pack $w.fileC.add -side left -pady 5 -padx 5

    # Option Menu command panel
    frame $w.optF
    label $w.optF.label -text "View:" -width 12 -anchor w
    set viewOptMenu [tk_optionMenu $w.optF.optB curNick " "]
    button $w.optF.stop -text "Stop" -command Stop

    pack $w.optF.label -side left 
    pack $w.optF.optB -side left -pady 5
    pack $w.optF.stop -side left -pady 5

    # create text widget
    frame $w.textf -bg red
    text $w.textf.text -height [expr $tailSize] -xscrollcommand "$w.textf.scrollh set" \
       -yscrollcommand "$w.textf.scrollv set" -bg lightblue
    set textw $w.textf.text
    scrollbar $w.textf.scrollh -orient horizontal -command "$w.textf.text xview"
    scrollbar $w.textf.scrollv -orient vertical -command "$w.textf.text yview"

    pack $w.textf.scrollv -side right -fill y -expand 1
    pack $w.textf.scrollh -side bottom -fill x -expand 1
    pack $w.textf.text -fill x -fill y -expand 1

    # pack all the frames
    [winfo toplevel $w.textf] configure -menu $w.menu
    pack $w.status -side bottom -fill x -pady 2m
    pack $w.file -side top -fill x -expand 1
    pack $w.fileC -side top -fill x -expand 1
    pack $w.optF -side top -fill x -expand 1
    pack $w.textf -side top -fill x -fill y -expand 1

}

# Once the user sets up a command or a file-type nick, the TailFile method will get called.
# This method makes sure that the specified file exists.
# It creates the command  and opens it as a process.
# Then, it binds a read event to the file descriptor and returns.
# The read event will call TailUpdate every time the file identifier associated
# with the process is readable.

#  TailFile --
#        
#        Show the tail of the request file.
#
#  Arguments:
#        file name to be tailed.
#        
#  Results:
#        The tail of the file is shown in the window.
#
proc TailFile { type file {nick ""}} {
    global tailSize tailFd  textw curNick 

    set w $textw
    catch {
        fileevent $tailFd readable {}
        close $tailFd
        update
    }
    $w delete 1.0 end

    if {$type == ""} {
        $w insert end "Illegal type...";
        return
    }
    if {$type == "file"} {
        if {$file == ""} {
            $w insert end "please specify a valid filename..."
            return
        }
        if ![file exists $file] {
            DeleteFromView $file
            $w insert end "file $file does not exist..."
            return
        }
        set nick $file
    } elseif {$type == "command"} {
        if {$file == ""} {
            $w insert end "please specify a command..."
            return
        }
    }

    if {$type == "file"} {
        set tailFd [open "|tail -f $file" r]
        wm title [winfo toplevel $w] "Tail tool \[tail -f $file\]"
    } elseif {$type == "command"} {
        if [catch {set tailFd [open "|$file" r]}] {
            SetStatus error  "can't execute command $file..."
            DeleteFromView $nick
            set curNick ""
            return
        }
        
        wm title [winfo toplevel $w] "Tail tool \[tail |$file\]"
    }      
    fconfigure $tailFd -blocking 0
    set lines 0
    fileevent $tailFd readable "TailUpdate \$tailFd"
}


# The TailUpdate procedure gets called as part of the event handler on the current log process read status.
# When this procedure gets called, it collects the output from the process and inserts it into the text widget.
# It also makes sure that at any given time, no more than $tailSize lines are shown in the text window.

proc TailUpdate {fileFd} {
   global textw curNick
   global tailSize tailFd

   set w $textw
   if [eof $tailFd] {
      fileevent $tailFd readable {}
      $w insert end "Tailing \"$curNick\" done..."
      return
   }

   set line [gets $tailFd]
   
   $w insert end $line
   $w insert end "\n"
   
   set lines [lindex [split [$w index end] .] 0]
   if {$lines == [expr $tailSize+1]} {
      $w delete 1.0 2.0
   }
   $w yview moveto 1.0

}

# The Stop call-back is used to stop the current logProcess.

# Stop the current tailing process.
proc Stop {} {
   global tailFd
   set pid [pid $tailFd]
   catch {exec kill -9 $pid}
}

# The AddNew procedure gets called every time the user adds a new shortcut.
# It creates a simple GUI for the user to create a new command nick.

#  AddNew --
#    Add a new tail file to the system
#
#  Arguments:
#    none.
#    
#  Results:
#    

proc AddNew {args} {
   toplevel .addnew 
   set w .addnew
   wm title $w "Add new tail file..."
   
   frame  $w.top  
   frame $w.sep -bd 2  -relief ridge
   frame $w.bot 


   set k $w.top
   
   label $k.name -text "Nickname for item:" 
   label $k.command -text "Command:"  

   grid $k.name -row 0 -column 0 -sticky e
   grid $k.command -row 1 -column 0 -sticky e

   entry $k.nameE -textvariable nameE -width 40
   entry $k.commandE -textvariable commandE -width 50

   grid $k.nameE -row 0 -column 1 -sticky ew
   grid $k.commandE -row 1 -column 1 -sticky ew
   
   grid columnconfigure $k 1 -weight 1
   grid propagate $k 1

   pack $w.top  -side top -fill both -expand 1
   pack $w.sep -side top -fill x -expand 1 -pady 5
   pack $w.bot -side top -fill x -expand 1
   

   button $w.bot.apply -text "Add" -command "AddToView \"command\"  \"\$commandE\" \"\$nameE\""
   button $w.bot.dismiss -text "Dismiss" -command {destroy .addnew}
   pack $w.bot.apply $w.bot.dismiss -side left -expand  1
   PositionWindow $w
}

# The SetStatus procedure is used to set GUI status messages in the status window.
# It's a general-purpose routine to display both error and informational messages.
# If a type error occurs, then an error bitmap will be displayed in the status window.

proc SetStatus {type text {timer 5000}} {
   global statusText  statusImgWin
   set statusText $text
   after $timer "set statusText \"\""
   $statusImgWin config -bitmap $type
   after $timer "$statusImgWin config -bitmap \"\""
}

# The AddToView command will add a nick to the option button.
# Before it adds the item to the option menu, it makes sure that the user had supplied
# the required information.

proc AddToView  {type command {nick ""}}  {
   global tailOpts  viewOptMenu
   

    catch {Stop}
   if {$type == "file"} {
      set nick $command
      if {$command == ""} {
          SetStatus error "Please supply File name..."         
      }
   } elseif  {$type == "command"} {
      if {($nick == "") || ($command == "") } {
         SetStatus error "Please supply both nick and command names..."
         return
      }
   }
   set l [list  "$type" "$nick" "$command"]
   if ![info exists tailOpts(wins)] {
      set tailOpts $l
      return
   } else {
      foreach item $tailOpts(wins) {
         if {$nick == [lindex $item 1]} {
            if {$type == "file"} {
               SetStatus info "File $nick is all ready in the tail list...."            
            } else {
               SetStatus info "Nick $nick is all ready in the tail list...."
            }
            return;
         }
      }
      lappend tailOpts(wins) $l
   }

   UpdateOptionMenu   
   $viewOptMenu invoke end
}

# The DeleteNicks routine will create a simple listbox-based user interface for the user to delete the nicks.

proc DeleteNicks {} {
   global   tailOpts

   if ![info exists tailOpts(wins)] {
      SetStatus info "No entries to delete..."
      return;
   }
   if {$tailOpts(wins) == {}} {
      SetStatus info "No entries to delete..."
      return;
   }
    catch {destroy .delent}
   toplevel .delent
   set w .delent
   wm title $w "Delete Entry"

   scrollbar $w.h -orient horizontal -command "$w.list xview"
   scrollbar $w.v -orient vertical -command "$w.list yview"
   listbox $w.l -selectmode single -width 20 -height 10 \
        -setgrid 1 -xscroll "$w.h set" -yscroll "$w.v set"

    frame $w.buts 
    button $w.buts.d -text "Delete" -command {
        set index [.delent.l curselection ];
        if {$index == ""} {return}
        set sel [.delent.l get $index ]; 
        puts "sel $sel ; index $index"
        DeleteFromView $sel;
        .delent.l  delete $index
    }

    button $w.buts.dismiss -text "Dismiss" -command "destroy $w"
    
    grid $w.l -row 0 -column 0 -columnspan 2 -sticky "news"
    grid $w.v -row 0 -column 2 -sticky "ns"
    grid $w.h -row 1 -column 0 -columnspan 2 -sticky "we"
    grid $w.buts -row 2 -column 0 -columnspan 3

    pack $w.buts.d $w.buts.dismiss -side left -padx 10

   foreach ent $tailOpts(wins) {
     $w.l insert end [lindex $ent 1]
   }

    PositionWindow $w
}    


# The DeleteFromView routine is an internal routine that removes the specified nick from the data structures
# and updates the optionbutton.

proc DeleteFromView {nick} {
   global tailOpts

    if {$nick == ""} {
        return
    }
   set newList {}
   if ![info exists tailOpts(wins)] {
      return
   }
   foreach item $tailOpts(wins) {
      if {$nick != [lindex $item 1]} {
         lappend newList $item
      } 
   }
   set tailOpts(wins) $newList
   UpdateOptionMenu
}

# The PositionWindow routine centers a toplevel dialogue box around its parent.
# It is used to map dialog boxes on the main window, instead of some far-away corner of the screen.

#
# PositionWindow  --
#	
#	Position the toplevel window centered to its parent.
#
#  Arguments:
#	toplevel window.
#	
#  Results:
#	Positions the window 
#

proc PositionWindow {w} {
   set paren [winfo parent $w]
   wm iconify $w
   set parenConf [wm geometry $paren]
   set parenConf [split $parenConf {+ - x}]
   set winConf [split [wm geometry $w] {+ - x}]
   set X [expr [lindex $parenConf 2] + [lindex $parenConf 0]/2 - \
	      [winfo reqwidth $w]/2]

   set Y [expr [lindex $parenConf 3] + [lindex $parenConf 1]/2 - \
	      [winfo reqheigh $w]/2]
   wm geometry $w +$X+$Y
   wm deiconify $w
}

# The UpdateOptionMenu command updates the nicks option menu widget.

#  UpdateOptionMenu --
#
#
#
#  Arguments:
#
#
#  Results:
#

proc UpdateOptionMenu {} {
   global tailOpts curNick viewOptMenu

   $viewOptMenu delete 0 end
   if ![info exists tailOpts(wins)] {
      return
   }
   if {$tailOpts(wins) == {}} {
      set curNick ""
      return
   }
   foreach item $tailOpts(wins) {
       $viewOptMenu add command -label [lindex $item 1] -command "catch Stop; TailFile  \"[lindex $item 0]\" \"[lindex $item 2]\" \"[lindex $item 1]\" "
      set curNick [lindex $item 1]
   }
}

# Finally, we map the main window.

wm withdraw .

toplevel .t

BuildTailGui .t