package require Tk
 ttk::style theme use clam
 # create it:
 ttk::treeview .tree
 pack .tree -expand 1 -fill both
 # insert an entry at the root level:
 set entry1 [.tree insert {} end -text "first item"]
 # and a second one:
 set entry2 [.tree insert {} end -text "second item"]
 # insert a new level with entry1 as parent:
 .tree insert $entry1 end -text "a sublevel"
 # insert another item under this one:
 .tree insert $entry1 end -text "another item"
 # suppose, one item is selected.
 # we can then delete it thus:
 .tree delete [.tree selection]

 # Also, to add the heading:
 .tree heading #0 -text Features
 # I also like the heading a little closer to the frame
 .tree configure -padding {0 0 0 0}

.tree insert {} end -id myitem2 -text "my text here"
.tree selection set myitem2 

    ttk::style layout Treeview {
      Entry.field -sticky news -border 2 -children {
        Treeview.padding -sticky news -children {
            Treeview.treearea -sticky news
        }
      }
    }

ttk::treeview .tree
pack .tree -side top

.tree insert {} end -id "Item 1" -text "Item 1"
.tree insert {} end -id "Item 2" -text "Item 2"
.tree insert {} end -id "Item 3" -text "Item 3"

.tree insert "Item 1" end -id "Item 1-1" -text "Item 1-1"
.tree insert "Item 1" end -id "Item 1-2" -text "Item 1-2"
.tree insert "Item 1" end -id "Item 1-3" -text "Item 1-3"

.tree insert "Item 2" end -id "Item 2-1" -text "Item 2-1"
.tree insert "Item 2" end -id "Item 2-2" -text "Item 2-2"
.tree insert "Item 2" end -id "Item 2-3" -text "Item 2-3"

% .tree selection
{Item 2} {Item 2-1} {Item 2-2} {Item 2-3} {Item 3}

% .tree selection
{Item 2} {Item 3}

bind Treeview <KeyPress> [list ::tv::treeviewKeyPress %W %A %K]
bind Treeview <KeyRelease> [list ::tv::treeviewKeyPressReset %A]
bind Treeview <FocusIn> [list ::tv::treeviewKeyPressReset ""]
bind Treeview <FocusOut> [list ::tv::treeviewKeyPressReset ""]

::tv::treeviewKeyPressReset

#: proc ::tv::treeviewKeyPress
#: arg tree Treeview widget
#: arg char The character typed; may be empty
#: arg keysym The keysym for the key pressed
#: desc Handle a keypress in a Treeview to allow typing to select an entry
#: return nothing
proc ::tv::treeviewKeyPress {tree char keysym} {
  variable tvkp;

  if { $char in [list "" " " "\t" "\n"] || $keysym eq "space"} {
       treeviewKeyPressReset;
       return;
     }

  catch {after cancel $tvkp(afterid)}

  if { $tvkp(error) } {
       bell -displayof $tree
     } elseif { $tvkp(reset) } {
       # set everything up
       set tvkp(reset) 0
       set sel [$tree selection]
       if { ![llength $sel] } {
            set tvkp(startid) ""
          } else {
            set tvkp(startid) [lindex $sel 0]
          }
       set tvkp(str) $char
       set tvkp(ids) [treeviewRecursiveListIDs $tree ""]
       if { ![llength $tvkp(ids)] } {
            set tvkp(error) 1
            bell -displayof $tree
          }
       set inc 0
     } else {
       append tvkp(str) $char
       set inc 1
     }

  $tree selection set [list]
  $tree focus {}
  if { !$tvkp(error) } {
       set len [string length $tvkp(str)]
       if { $tvkp(startid) eq "" } {
            set index 0
          } else {
            set index [lsearch -exact $tvkp(ids) $tvkp(startid)]
            if { !$inc } {
                 incr index
                 if { $index == [llength $tvkp(ids)] } {
                      set index 0
                    }
               }
          }
       set ids [concat [lrange $tvkp(ids) $index end] [lrange $tvkp(ids) 0 $index-1]]
       set match ""
       foreach x $ids {
         if { [set text [$tree item $x -text]] eq "" } {
              set text [lsearch -inline -glob [$tree item $x -values] "?*"]
            }
         if { $text eq "" } {
              continue;
            }
         if { [string equal -nocase -length $len $tvkp(str) $text] } {
              set match $x
              break;
            }
       }
       if { $match ne "" } {
            $tree sel set [list $x]
            $tree focus $x
            $tree see $x
            set tvkp(startid) $x
          } else {
            set tvkp(error) 1
            bell -displayof $tree
          }
     }

  set tvkp(afterid) [after $tvkp(aftertime) [list ::tv::treeviewKeyPressReset]]

  return;


};# ::tv::treeviewKeyPress

#: proc ::tv::treeviewKeyPressReset
#: arg char Character generated if this was triggered by a key release; only reset for non-printable keys ($char eq "")
#: desc Reset the $tvkp array used to hold state data for treeview keypresses
#: return nothing
proc ::tv::treeviewKeyPressReset {{char ""}} {
  variable tvkp;

  if { $char ne "" } {
       return;
     }

  set tvkp(str) ""
  set tvkp(startid) ""
  set tvkp(ids) [list]
  set tvkp(reset) 1
  set tvkp(error) 0
  if { [info exists tvkp(afterid)] } {
       catch {after cancel $tvkp(afterid)}
     }
  set tvkp(afterid) ""
  set tvkp(aftertime) 1300

  return;

};# ::tv::treeviewKeyPressReset

#: proc ::tv::treeviewRecursiveListIDs
#: arg tree Tree widget
#: arg id parent id
#: desc Return a list of $id and all its children in the tree widget $tree. Used
#: desc recursively for building a list of all IDs in order
#: return list of ids
proc ::tv::treeviewRecursiveListIDs {tree id} {

  if { ![winfo exists $tree] || ![$tree exists $id] } {
       return;
     }

  set res [list]
  if { $id ne "" } {
       lappend res $id
     }
  foreach x [$tree children $id] {
    lappend res {*}[treeviewRecursiveListIDs $tree $x]
  }

  return $res;

};# ::tv::treeviewRecursiveListIDs

image create photo Img -height 5 -width 5
Img put red -to 0 0 4 4
pack [ttk::treeview .t] -fill both -expand true
.t tag configure t -font {size 20} -image Img
set p [.t insert {} end -text A -tag t -open 1]
.t insert $p end -text B -tag t -open 1

-rowheight [expr {round($fontsize*2/[tk scaling])}]

image create photo Img -height 5 -width 5
Img put red -to 0 0 4 4
font create LabelFont -size 20
label .test -text M -font LabelFont
ttk::style configure Treeview -rowheight [winfo reqheight .test] -font LabelFont
destroy .test
pack [ttk::treeview .t] -fill both -expand true
set p [.t insert {} end -text Text -image Img]
.t insert $p end -text B -open 1

# use of ttk::treeview to build a table

# proc newTable
# creates a new treeview configured as a table
proc newTable {w colnames} {
    # create the tree showing headings only, and define column names
    set t [ttk::treeview $w.tree -show headings -columns $colnames]

    # set the text display for columns headers
    foreach colname $colnames {
        $t heading $colname -text $colname
    }
    pack $t -expand 1 -fill both
    return $t
}

# proc newRow
# creates a new row in the treeview and optionally set values
proc newRow {t {values ""}} {
    
    # insert a new item
    set item [$t insert {} end]

    # fill each column with valu
    foreach col [$t cget -columns] val $values {
        $t set $item $col $val
    }
}

# example
# -- create a new table
set table [newTable . [list col1 col2 col3 col4]]
# -- set values for all columns
newRow $table [list 1 2 3 4]
# -- add an empty row
newRow $table 
# -- add a row with 2 values (fills 2 first columns)
newRow $table [list "value one" "value two"]