# Source window for Insight.
# Copyright 1997, 1998, 1999, 2000, 2001, 2002, 2003 Red Hat, Inc.
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License (GPL) as published by
# the Free Software Foundation; either version 2 of the License, or (at
# your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.


# ------------------------------------------------------------------
#  CONSTRUCTOR - create new source window
# ------------------------------------------------------------------
itcl::body SrcWin::constructor {args} {
  debug "$args"
  eval itk_initialize $args
  set top [winfo toplevel $itk_interior]

  _update_title ""

  set Tracing [pref get gdb/mode]
  set current(filename) ""

  if {[catch {_build_win} mssg]} {
    dbug E "_build_win returned: $::errorInfo"
  }

  # add special delete handler
  wm protocol $top WM_DELETE_WINDOW "[code $this _exit]"

  # add hooks
  add_hook gdb_no_inferior_hook "$this no_inferior"
  add_hook download_progress_hook "$this download_progress"
  add_hook state_hook [code $this _set_state]
  add_hook gdb_clear_file_hook [code $this clear_file]
  after idle "
      update idletasks
      $this sizeWinByChild toolbar"

  lappend window_list $this
}

# ------------------------------------------------------------------
#  DESTRUCTOR - destroy window containing widget
# ------------------------------------------------------------------
itcl::body SrcWin::destructor {} {
  debug
  remove_hook gdb_no_inferior_hook "$this no_inferior"
  remove_hook download_progress_hook "$this download_progress"
  remove_hook state_hook [code $this _set_state]
  remove_hook gdb_clear_file_hook [code $this clear_file]
  set window_list [lremove $window_list $this]
  if {$pc_window == $this} then {
    set pc_window ""
  }
}

# ------------------------------------------------------------------
#  PRIVATE METHOD:  _build_win - build the main source window
# ------------------------------------------------------------------
itcl::body SrcWin::_build_win {} {
  global gdb_downloading gdb_running gdb_loaded

  # build source toolbar
  set _toolbar [conAdd toolbar -resizable 0]
  SrcBar $_toolbar $this \
    -updatecommand [list $this toggle_updates] \
    -updatevalue $do_updates
  pack $_toolbar -expand 1 -fill both

  # if user likes control on bottom...
  if {! [pref get gdb/src/top_control]} {

    # add a SrcTextWin container
    set srcwin [conAdd src]
    set twin [SrcTextWin $srcwin -Tracing $Tracing -parent $this]
    pack $srcwin -expand 1 -fill both

    # add status line
    set _status [conAdd status -resizable 0]
    label $_status -relief sunken -bd 3 -font global/status -height 1
    pack $_status -expand 1 -fill both
  }
  
  # add a status bar container
  set _statbar [conAdd stat -resizable 0]
  frame $_statbar
  pack $_statbar -expand 1 -fill both

  combobox::combobox $_statbar.name -maxheight 15 -font global/fixed\
    -command [code $this _name] -bg $::Colors(textbg)
  
  set need_files 1
  
  combobox::combobox $_statbar.func -maxheight 15 -font global/fixed\
    -command [code $this goto_func] -bg $::Colors(textbg)
  combobox::combobox $_statbar.mode -width 9 -editable false \
    -font global/fixed -command [code $this mode] -bg $::Colors(textbg)
  
  $_statbar.mode list insert end SOURCE
  $_statbar.mode list insert end ASSEMBLY
  $_statbar.mode list insert end MIXED
  $_statbar.mode list insert end SRC+ASM

  pack $_statbar.mode -side right -padx 10 -pady 4
  pack $_statbar.name $_statbar.func -side left -pady 4 -padx 10

  # if user likes control on top...
  if {[pref get gdb/src/top_control]} {
  
    # add a SrcTextWin container
    set srcwin [conAdd src]
    set twin [SrcTextWin $srcwin -Tracing $Tracing -parent $this]
    pack $srcwin -expand 1 -fill both

    # add status line
    set _status [conAdd status -resizable 0]
    set _statusframe [frame $_status]
    set _status $_statusframe.con
    label $_status -relief sunken -bd 3 -font global/status -height 1 \
      -anchor w

    # add download progress meter
    canvas $_statusframe.progress -relief sunken -borderwidth 2 \
      -highlightthickness 0 -takefocus 0 -width 100 -height 0 -confine 1
    $_statusframe.progress create rectangle 0 0 0 \
      [winfo height $_statusframe.progress] -outline blue -fill blue -tags rect

    # add address and line number indicators
    label $_statusframe.addr -text "" -width 10 -relief sunken \
      -bd 1 -anchor e -font global/fixed
    label $_statusframe.line -text "" -width 6 -relief sunken \
      -bd 1 -anchor e -font global/fixed

    balloon register $_statusframe.addr "Address"
    balloon register $_statusframe.line "Line number"

    pack $_statusframe -expand 1 -fill both
    grid $_status -row 0 -column 1 -sticky news -pady 2 -padx 2
    grid $_statusframe.addr -row 0 -column 3 -sticky nes -pady 4
    grid $_statusframe.line -row 0 -column 4 -sticky nws -pady 4
    grid columnconfigure $_statusframe 1 -weight 10
    grid columnconfigure $_statusframe 2 -minsize 5
    grid columnconfigure $_statusframe 5 -minsize 5
  }

  set_execution_status

  # balloon help
  foreach i {entry button} {
    balloon register $_statbar.name.$i "Current file name"
    balloon register $_statbar.func.$i "Current function name"
    balloon register $_statbar.mode.$i "Source mode"
  }
  balloon variable $_status ${twin}_balloon

  $_statbar.mode entryset [$twin mode_get]

  # time to load the widget with a file.
  # If this is a new widget and the program is
  # not yet being debugged, load the file with "main" in it.
  if {$gdb_running} {
    if {[catch {gdb_loc} loc]} {
      # Nothing we can do but leave the window empty.
    } else {
      _update $loc
    }
  } else {
    if {[set linespec [gdbtk_locate_main]] != ""} {
      location BROWSE_TAG $linespec
    }
  }
}


# ------------------------------------------------------------------
#  PUBLIC METHOD:  _set_state - do things when program state changes
# ------------------------------------------------------------------
itcl::body SrcWin::_set_state {varname} {
  global gdb_running gdb_downloading gdb_loaded gdb_program_has_run
  debug "$varname l=$gdb_loaded d=$gdb_downloading r=$gdb_running"

  if {$varname == "gdb_loaded" && $gdb_loaded == 1} {
    set gdb_program_has_run 0
    #set current(filename) ""
    return
  }

  if {$gdb_running} {
    set state normal
    set gdb_program_has_run 1
  } else {
    set state disabled
  }
  if {!$Tracing} {
    $twin SetRunningState $state
  }
}

# ------------------------------------------------------------------
#  PUBLIC METHOD:  download_progress - update the progress meter when downloading
# ------------------------------------------------------------------
itcl::body SrcWin::download_progress { section num tot {msg ""} } {
  global download_start_time download_cancel_ok gdb_loaded

  #debug "$section $num $tot $msg"
  if {$last_section_start == 0} {
    grid forget $_statusframe.addr $_statusframe.line
    grid $_statusframe.progress -row 0 -column 4 -padx 4 -sticky news
    ::update idletasks
  }

  if {$section == "DONE"} {
    set last_done $tot
    if {$gdb_loaded} {
      # loaded something
      set secs [expr {[clock seconds] - $download_start_time}]
      if {$secs} {
	set bps [expr {8 * $tot / $secs}]
	set_status "DOWNLOAD FINISHED: $tot bytes in $secs seconds ($bps bits per second)"
      } else {
	set_status "DOWNLOAD FINISHED"
      }
    }
  } elseif {$section != "CANCEL"} {
    if {$section != $last_section} {
      set last_section $section
      set last_section_start $last_done
    }
    set last_done [expr {$last_section_start + $num}]
    set_status "Downloading section $section - $num bytes"
  }

  set canvas $_statusframe.progress
  set height [winfo height $canvas]
  if {$last_done} {
    set width [winfo width $canvas]
    set rw [expr {double ($last_done) * $width / $tot}]
    $canvas coords rect 0 0 $rw $height
    ::update
  }

  if {$last_done == $tot || $section == "CANCEL"} {
    $_toolbar configure -runstop normal
    if {!$gdb_loaded} {
      ::update
      # errored or canceled
      if {$msg != ""} {
	set_status "DOWNLOAD FAILED: $msg"
      } else {
	set_status "DOWNLOAD CANCELLED"
      }
      $canvas coords rect 0 0 0 $height
      ::update idletasks
    }

    set last_section ""
    set last_done 0
    set last_section_start 0

    grid forget $_statusframe.progress
    grid $_statusframe.addr -row 0 -column 3 -sticky new -pady 4
    grid $_statusframe.line -row 0 -column 4 -sticky nws -pady 4
    ::update idletasks
  }
}

# ------------------------------------------------------------------
#  PUBLIC METHOD:  reconfig - used when preferences change
# ------------------------------------------------------------------
itcl::body SrcWin::reconfig {} {
  debug
  $_toolbar reconfig
  $twin reconfig
}


# ------------------------------------------------------------------
#  PRIVATE METHOD:  _name - filename combobox callback
#  This is only called when the user edits the name combobox.
#  It is the only way that files can be inserted into the file list
#  once the debugger is started. 
# ------------------------------------------------------------------
itcl::body SrcWin::_name {w {val ""}} {
  global _files
  debug "$w $val"
  if {$val != ""} {
    if {![info exists _files(short,$val)]} {
      if {![info exists _files(full,$val)]} {
	if [catch {gdb_find_file $val} full] {
	  set_status "Cannot find source file \"$val\": $full"
	  $_statbar.name entryset [lindex [file split $current(filename)] end]
	  return
	}
	if {$full == ""} {
	  set_status "Cannot find source file \"$val\""
	  $_statbar.name entryset [lindex [file split $current(filename)] end]
	  return
	}
	set _files(short,$full) $val
	set _files(full,$val) $full
      }
      set full $_files(full,$val)
    } else {
      set full $val
      set val $_files(short,$full)
    }
    $_statbar.name entryset $val
    location BROWSE_TAG [list $val "" $full 0 0 0 {}]
  }
}

# ------------------------------------------------------------------
#  PRIVATE PUBLIC METHOD:  toggle_updates - update toggle callback
# ------------------------------------------------------------------
itcl::body SrcWin::toggle_updates {value} {
  # save state in do_updates so it will be preserved
  # in window reconfigs
  set do_updates $value
}

# ------------------------------------------------------------------
#  PRIVATE PUBLIC METHOD:  goto_func - function combobox callback
# ------------------------------------------------------------------
itcl::body SrcWin::goto_func {w {val ""}} {
  if {$val != ""} {
    set mang 0
    if {[info exists _mangled_func($val)]} {
      set mang $_mangled_func($val)
    }
    if {$mang} {
      set loc $val
    } else {
      set fn [lindex [::file split $current(filename)] end]
      if {$fn == ""} {
	set loc $val
      } else {
	set loc $fn:$val
      }
    }
    debug "GOTO $loc"
    if {![catch {gdb_loc $loc} result]} {
      location BROWSE_TAG $result
    } else {
      dbug W "gdb_loc returned \"$result\""
    }
  }
}

# ------------------------------------------------------------------
#  PUBLIC METHOD:  fillNameCB - fill the name combobox
#
#         This method needs to be public, since other parts of
#         the gui can cause new symbols to be read.
# ------------------------------------------------------------------
itcl::body SrcWin::fillNameCB {} {
  global _files
  set allfiles [gdb_listfiles]
  foreach f $allfiles {
    # FIXME: If you reactivate this code add a catch as gdb_find_file can err
    # (P.S.: I don't know why this is commented out)
    #set fullname [gdb_find_file $f]
    #set _files(full,$f) $fullname
    #set _files(short,$fullname) $f
    $_statbar.name list insert end $f
  }
  set need_files 0
}


# ------------------------------------------------------------------
#  PUBLIC METHOD:  fillFuncCB - fill the function combobox
#
#         This method needs to be public, since other parts of
#         the gui can cause new symbols to be read.
# ------------------------------------------------------------------
itcl::body SrcWin::fillFuncCB {name} {
  $_statbar.func list delete 0 end
  if {$name != ""} {
    set maxlen 10
    if {[catch {gdb_listfuncs $name} listfuncs]} {
      tk_messageBox -icon error -default ok \
	-title "GDB" -type ok \
	-message "This file can not be found or does not contain\ndebugging information."
      _set_name ""
      return
    }
    foreach f [lsort -increasing $listfuncs] {
      lassign $f func mang
      set _mangled_func($func) $mang
      $_statbar.func list insert end $func
      if {[string length $func] > $maxlen} {
	set maxlen [string length $func]
      }
    }
    $_statbar.func configure -width [expr $maxlen + 1]
  }
}

# ------------------------------------------------------------------
#  PUBLIC METHOD:  location - update the location displayed
#
#  a linespec looks like this:
#  0: basename of the file
#  1: function name
#  2: full filename
#  3: source line number
#  4: address
#  5: current PC - which will often be the same as address, but not when
#     we are browsing, or walking the stack.
#  6: shared library name if the pc is in a shared lib
#
# linespec will be "{} {} {} 0 0x0 0x0" when GDB has not started debugging.
# ------------------------------------------------------------------
itcl::body SrcWin::location {tag linespec} {
  global gdb_running gdb_exe_name _files tcl_platform

  # We need to keep track of changes to the line, filename, function name
  # and address so we can keep the widgets up-to-date.  Otherwise we
  # basically pass things through to the SrcTextWin location public method.

  debug "running=$gdb_running tag=$tag linespec=$linespec"    
  lassign $linespec foo funcname name line addr pc_addr lib

  # need to call this to update running state
  set_execution_status $line $addr

  # "update" doesn't set the tag so we do it here
  if {$tag == ""} {
    if {$addr == $pc_addr} {
      set tag PC_TAG
    } else {
      set tag STACK_TAG
    }
  }
  
  if {!$gdb_running} {
    # When we are not yet debugging, we need to force something
    # to be displayed, so we choose to find function "main" and
    # display the file with it.
    set tag BROWSE_TAG
    debug "not running: name=$name funcname=$funcname line=$line"
    if {$name == ""} {
      if {[set linespec [gdbtk_locate_main]] == ""} {
	# no "main" function found
	return 
      }
      lassign $linespec foo funcname name line addr pc_addr lib
      debug "new linespec=$linespec"    
    }
  }

  # update file and function combobox
  if {$name != $current(filename)} {
    _set_name $name
    fillFuncCB $name
  }

  # get a proper address string to display
  set textaddr [gdb_CA_to_TAS $addr]

  # set address and line widgets
  if {[string length $textaddr] > 8} {
    # 64-bit address
    set width 16
  } else {
    # 32-bit address
    set width 8
  }
  $_statusframe.addr configure -text $textaddr -font global/fixed -width $width
  $_statusframe.line configure -text $line

  # set function combobox
  $_statbar.func entryset $funcname

  # call SrcTextWin::location
  $twin location $tag $name $funcname $line $addr $pc_addr $lib

  set current(filename) $name
}

# ------------------------------------------------------------------
#  PUBLIC METHOD:  stack - handle stack commands
# ------------------------------------------------------------------
itcl::body SrcWin::stack {cmd} {
  if {$cmd == "bottom"} {
    set cmd "frame 0"
  }
  gdbtk_busy
  if {[catch {gdb_cmd "$cmd"} message]} {
    dbug E "STACK ERROR: $message"
  }
  gdbtk_update
  gdbtk_idle
}

# ------------------------------------------------------------------
#  METHOD:  _update - update widget when PC changes
# ------------------------------------------------------------------
itcl::body SrcWin::_update {loc} {
  debug "loc=$loc"
  # See if name combobox needs filled.
  if {$need_files} {
    fillNameCB
  }
  location "" $loc
}

# ------------------------------------------------------------------
#  PUBLIC METHOD:  idle - callback for gdbtk_idle
#  Called when the target is idle, so enable all buttons.
# ------------------------------------------------------------------
itcl::body SrcWin::idle {event} {
  $_toolbar configure -runstop normal
  enable_ui 1
}

# ------------------------------------------------------------------
#  PUBLIC METHOD:  mode - set mode to SOURCE, ASSEMBLY, MIXED, SRC+ASM
# ------------------------------------------------------------------
itcl::body SrcWin::mode {w new_mode {go 1}} {
  gdbtk_busy
  $_statbar.mode entryset $new_mode
  catch {$twin mode_set $new_mode $go} errorVal
  $_toolbar configure -displaymode $new_mode
  gdbtk_idle
}

# ------------------------------------------------------------------
#  PRIVATE METHOD:  _update_title - update title bar
# ------------------------------------------------------------------
itcl::body SrcWin::_update_title {name} {
  set fn [lindex [::file split $name] end]
  if {$fn == ""} {
    set prefix ""
  } else {
    set prefix "$fn - "
  }
  window_name "${prefix}Source Window" $fn
}

# ------------------------------------------------------------------
#  PUBLIC METHOD:  busy - disable things when gdb is busy
# ------------------------------------------------------------------
itcl::body SrcWin::busy {event} {
  global gdb_loaded gdb_target_name
#  debug "gdb_loaded=$gdb_loaded, gdb_target_name=$gdb_target_name"

  if {$do_updates} {
    enable_ui 0
    if {$Running} {
      $_toolbar configure -runstop running
      if {$gdb_loaded || \
	    ([TargetSelection::native_debugging] && $gdb_target_name != "remote")} {
	set_status "Program is running."
      } 
    } else {
      $_toolbar configure -runstop busy
    }
  }
}

# ------------------------------------------------------------------
#   PUBLIC METHOD:  update - The inferior's state has changed.
# ------------------------------------------------------------------
itcl::body SrcWin::update {event} {

  # FIXME: This is kinda lame. We need to run this only once
  # as it is now written, so only the first window in the list
  # will actually call choose_and_update.
  # This is still better than before, since it will not
  # matter if this window is destroyed: as long as _a_
  # SrcWin exists, this will get called.
  if {[lindex $window_list 0] == $this} {
    choose_and_update
  }
}

# ------------------------------------------------------------------
#  PRIVATE METHOD:  _set_name - set the name in the name combobox and in the title
# ------------------------------------------------------------------
itcl::body SrcWin::_set_name { val {found 1} } {
  global _files
  _update_title $val
  if {![info exists _files(short,$val)]} {
    if {![info exists _files(full,$val)]} {
      # not in our list; just display basename
      $_statbar.name entryset [lindex [::file split $val] end]
      return
    }
  } else {
    set val $_files(short,$val)
  }
  if {$found} {
    $_statbar.name entryset $val
  } else {
    $_statbar.name entryset "$val (not found)"
  }
}

# ------------------------------------------------------------------
#  PUBLIC METHOD:  set_status - write a message to the status line.
#  If "tmp" is set, the status change will not be saved.
# ------------------------------------------------------------------

itcl::body SrcWin::set_status { {msg ""} {tmp 0} } {
  set msg [lindex [split $msg \n] 0]
  if {$tmp} {
    $_status configure -text $msg
    return
  }
  if {$msg != ""} {
    set saved_msg $msg
  }
  $_status configure -text $saved_msg
}

# ------------------------------------------------------------------
#  PUBLIC METHOD:  set_execution_status - write the current execution state 
#  to the status line
# ------------------------------------------------------------------
itcl::body SrcWin::set_execution_status { {line ""} {pc ""}} {
  global gdb_running gdb_loaded gdb_program_has_run gdb_target_changed
  #debug "line=$line pc=$pc [gdb_target_has_execution] running=$gdb_running loaded=$gdb_loaded"
  set message ""

  if {![gdb_target_has_execution]} {
    if {$gdb_running} {
      set gdb_running 0
      # tell text window program is no longer running
      $twin ClearTags
    }
    if {$gdb_loaded} {
      if {$gdb_program_has_run} {
	set message "Program terminated. 'Run' will restart."
	# Need to set gdb_target_changed because most
	# remote targets detach when they are finished, 
	# and this will force it to reattach.
	set gdb_target_changed 1
	set gdb_running 0
      } else {
	set message "Program is ready to run."
      }
    } else {
      set message "Program not running. Click on run icon to start."
    }
  } else {

    # gdb_target_has_execution has returned true, so we must be running.
    #
    # This can cause problems on targets which do not set inferior_pid.
    # Although this is bogus, much of gdb (and gdbtk) relies on
    # gdb_target_has_execution (and thus inferior_pid), so we should
    # not try to second guess it and fix those targets which do not set
    # inferior_pid when opened.
    set gdb_running 1

    # only do a gdb_loc if we have to
    if {$line == "" && $pc == ""} {
      if {[catch {gdb_loc} loc] == 0} {
	set line [lindex $loc 3] 
	set pc [lindex $loc 4]
      }
    }

    set pc [gdb_CA_to_TAS $pc]

    if {$line == "" || $line == 0} {
      if {$pc == "" || $pc == 0} {
	if {$Tracing} {
	  set message "Ready."
	} else {
	  set message "Program stopped."
	}
      } else {
	set message "Program stopped at 0x$pc"
      }
    } else {
      if {$Tracing} {
	set msg "Inspecting trace"
      } else {
	set msg "Program stopped"
      }
      switch [$twin mode_get] {
	ASSEMBLY {set message "$msg at 0x$pc" }
	MIXED {set message "$msg at line $line, 0x$pc" }
	SRC+ASM {set message "$msg at line $line, 0x$pc" }
	default {set message "$msg at line $line" }
      }
    }
  }
  set_status $message
}

# ------------------------------------------------------------------
#  PUBLIC METHOD:  edit - invoke external editor
# ------------------------------------------------------------------
itcl::body SrcWin::edit {} {
  global external_editor_command
  # If external editor is enabled, pass the file to the specified command

  if {$current(filename) == ""} {
    tk_dialog .warn {Edit} {No file is loaded in the source window.} error 0 Ok
    return
  }

  if {[catch {$twin report_source_location} loc_info]} {
    tk_dialog .warn "Edit" "No source file selected" error 0 Ok
    return
  }

  Editor::edit $loc_info
}

# ------------------------------------------------------------------
#  PUBLIC METHOD:  print - print the contents of the text widget
# ------------------------------------------------------------------
itcl::body SrcWin::print {} {
  # Call the SrcTextWin's print public method
  $twin print $top
}

# ------------------------------------------------------------------
# PUBLIC METHOD:   enable_ui
#              Enable all UI elements for user interaction.
# ------------------------------------------------------------------
itcl::body SrcWin::enable_ui { on } {
  #debug "$on"
  if {$on} {
    set Running 0
    set state normal
    set glyph ""
  } else {
    if {!$NoRun} {set Running 1}
    set state disabled
    set glyph watch
  }
  # combo boxes
  $_statbar.mode configure -state $state
  $_statbar.name configure -state $state
  $_statbar.func configure -state $state

  $twin enable $on
  $top configure -cursor $glyph
}

# ------------------------------------------------------------------
# PUBLIC METHOD:   no_inferior
#              Put the UI elements of this object into a state
#              appropriate for an inferior which is not executing.
#              For this object, this means:
# Disable:
# - key binding for all inferior control (not needed -- gdb does this
#    for us)
#
# Enable:
# - file/func/mode selectors
# - right-click popups, since gdb DOES allow looking at exe fil
# - selections
# 
# Change mouse pointer to normal
# ------------------------------------------------------------------
itcl::body SrcWin::no_inferior {} {
  #debug
  set_execution_status
  enable_ui 1
}

# ------------------------------------------------------------------
#   PUBLIC METHOD: reset - reset the source window
# ------------------------------------------------------------------  
itcl::body SrcWin::reset {} {
  set current(filename) ""
  set need_files 1
  set do_updates 1
  set last_section ""
  set last_section_start 0
  set last_done 0
  set saved_msg ""

  # do we need to flush the cache or clear the source windows?

  # Empty combo boxes
  $_statbar.name list delete 0 end
  $_statbar.name configure -value {}
  $_statbar.func list delete 0 end
  $_statbar.func configure -value {}
}

# ------------------------------------------------------------------
#  PUBLIC METHOD:  search - search for a STRING or jump to a specific line
#           in source window, going in the specified DIRECTION.
# ------------------------------------------------------------------
itcl::body SrcWin::search {direction string} {
  set_status
  set_status [$twin search $string $direction] 1
}

# ------------------------------------------------------------------
#  PROCEDURE: point_to_main
#         Proc that may be called to point some source window to
#         main (or an entry point?). (see gdbtk_tcl_exec_file_changed)
# ------------------------------------------------------------------
itcl::body SrcWin::point_to_main {} {
  # We need to force this to some default location. Assume main and
  # if that fails, let the source window guess (via gdb_loc using stop_pc).
  set src [lindex [ManagedWin::find SrcWin] 0]
  if {[set linespec [gdbtk_locate_main]] == ""} {
    gdbtk_update
    debug "could not find main"
  } else {
    $src location BROWSE_TAG [list $linespec]
  }
}

itcl::body SrcWin::_exit {} {
  debug
  if {[llength [ManagedWin::find SrcWin]] == 1} {
    if {![gdbtk_quit_check]} {
      return
    }
  }
  after idle [delete object $this]
}

# public method for testing use only!
itcl::body SrcWin::test_get {var {private_func 0}} {
  debug $var
  if {$private_func} {
    return [code $this $var]
  }
  return [set $var]
}

# ------------------------------------------------------------------
#  PUBLIC METHOD: toolbar - configure the toolbar's "state"
# ------------------------------------------------------------------
#
#  This method is used to configure the toolbar's running state.
#  Valid states include anything that the "runtest" variable of
#  the GDBSrcBar may accept. Specifically,
#
#  busy        - Run button becomes disabled
#  running     - Stop button appears, allowing user to stop executing target
#  downloading - Stop button appears, allowing user to interrupt downloading
#  normal      - Run button appears, allowing user to run/re-run exe
itcl::body SrcWin::toolbar {state} {
  $_toolbar configure -runstop $state
}

# ------------------------------------------------------------------
#  METHOD:  inferior - change execution state of inferior
# ------------------------------------------------------------------
#
# ACTION may be:
#   step       -  step the inferior one source line (stepping into functions)
#   next       -  step the inferior one source line (stepping over functions)
#   finish     -  finish the current frame of execution
#   continue   -  continue executing the inferior
#   stepi      -  step one machine instruction (stepping into calls)
#   nexti      -  step one machine instruction (stepping over calls)
#   run        -  run/re-run the inferior
#   stop       -  stop or detach from target
#
# FIXME: This should really be in an object which describes gdb's state.
# Unfortunately, this doesn't exist, so it's here for now.
itcl::body SrcWin::inferior {action} {

  switch $action {
    step { gdbtk_step }

    next { gdbtk_next }

    finish { gdbtk_finish }

    continue { gdbtk_continue }

    stepi { gdbtk_stepi }

    nexti { gdbtk_nexti }

    run { gdbtk_run }

    stop { gdbtk_stop }
  }
}

# ------------------------------------------------------------------
#  METHOD:  clear_file
#  Tasks for SrcWin to clear file:
#
# - clear window
# - reset to src mode
# - clear func/file comboboxes
# - clear status (done by no_inferior)
# - allow SrcTextWin to clear_file
# ------------------------------------------------------------------
itcl::body SrcWin::clear_file {} {

  # Reset to Source mode
  if {[$twin mode_get] != "SOURCE"} {
    mode {} SOURCE 0
  }

  no_inferior
  reset

  # run srctextwin clear_file
  $twin clear_file
}

# ------------------------------------------------------------------
#  METHOD:  get_file
#  Return name of displayed file, or empty string if no file.
# ------------------------------------------------------------------
itcl::body SrcWin::get_file {} {
  if {$twin == ""} {
    return ""
  } else {
    return [$twin get_file]
  }
}

# ------------------------------------------------------------------
#  METHOD:  is_fixed
#  Return boolean indicating whether this window is fixed.
# ------------------------------------------------------------------
itcl::body SrcWin::is_fixed {} {
  return 0
}

# ------------------------------------------------------------------
#  METHOD:  get_top
#  Return toplevel
# ------------------------------------------------------------------
itcl::body SrcWin::get_top {} {
  return $top
}

# ------------------------------------------------------------------
#  METHOD:  _set_tag_to_stack
#  Set tag to `stack' and update the underlying window.
# ------------------------------------------------------------------
itcl::body SrcWin::_set_tag_to_stack {} {
  set tag STACK_TAG
  if {$twin != ""} then {
    $twin set_tag_to_stack
  }
}

# ------------------------------------------------------------------
#  METHOD:  _choose_window
#  Choose the right source window.
# ------------------------------------------------------------------
itcl::body SrcWin::_choose_window {file} {
  # Find the next available source window.  The rules are:
  # 1. LRU overall
  # 2. Skip iconified windows
  # 3. If a window already shows the file, use it.  Prefer the
  #    window currently showing the PC
  # 4. If the window is fixed, skip it
  if {$pc_window != ""} then {
    if {[$pc_window get_file] == $file} then {
      return $pc_window
    }
  }

  set choice ""
  foreach win $window_list {
    if {[wm state [$win get_top]] != "normal"} then {
      continue
    }

    if {[$win get_file] == ""
	|| [$win get_file] == $file
	|| ! [$win is_fixed]} then {
      set choice $win
      break
    }
  }

  # If we didn't find an available window, then pick the current PC
  # window.
  if {$choice == ""} then {
    set choice $pc_window
  }

  set window_list [lremove $window_list $choice]
  lappend window_list $choice

  return $choice
}

# ------------------------------------------------------------------
#  METHOD:  choose_and_update
#  Choose the right source window and then cause it to be updated
# ------------------------------------------------------------------
itcl::body SrcWin::choose_and_update {} {
  if {$pc_window == ""} then {
    set pc_window [lindex $window_list 0]
  }

  if {$pc_window == ""} then {
    # Nothing.
  } elseif {[catch {gdb_loc} loc]} {
    $pc_window set_execution_status
  } else {
    set prev $pc_window
    set file [lindex $loc 2]
    set pc_window [_choose_window $file]
    debug "chose window $pc_window"
    $pc_window _update $loc
    if {$pc_window != $prev} then {
      $pc_window reveal
      $prev _set_tag_to_stack
    }
  }
}

# ------------------------------------------------------------------
#  METHOD:  choose_and_display
#  Choose the right source window for a given file
# ------------------------------------------------------------------
itcl::body SrcWin::choose_and_display {tag linespec} {
  set file [lindex $linespec 2]
  set window [_choose_window $file]
  $window location $tag $linespec
}
