ruby--ruby/ext/tk/sample/demos-en/image3.rb

# image3.rb
#
# This demonstration script creates a simple collection of widgets
# that allow you to select and view images in a Tk label.
#
# widget demo 'load image' (called by 'widget')
#

# toplevel widget
if defined?($image3_demo) && $image3_demo
  $image3_demo.destroy 
  $image3_demo = nil
end

# demo toplevel widget
$image3_demo = TkToplevel.new {|w|
  title('Image Demonstration #3')
  iconname("Image3")
  positionWindow(w)
}

# 
def loadDir(w)
  w.delete(0,'end')
  Dir.glob([$dirName,'*'].join(File::Separator)).sort.each{|f|
    w.insert('end',File.basename(f))
  }
end

# selectAndLoadDir --
# This procedure pops up a dialog to ask for a directory to load into
# the listobx and (if the user presses OK) reloads the directory
# listbox from the directory named in the demo's entry.
#
# Arguments:
# w -                   Name of the toplevel window of the demo.
def selectAndLoadDir(w, lbox)
  dir = Tk.chooseDirectory(:initialdir=>$dirName.value, 
                           :parent=>w, :mustexist=>true)
  if dir.length > 0
    $dirName.value = dir 
    loadDir(lbox)
  end
end

def loadImage(w,x,y)
  $image3a.file([$dirName, w.get("@#{x},#{y}")].join(File::Separator))
end


# label
msg = TkLabel.new($image3_demo) {
  font $font
  wraplength '4i'
  justify 'left'
  text "This demonstration allows you to view images using a Tk \"photo\" image.  First type a directory name in the listbox, then type Return to load the directory into the listbox.  Then double-click on a file name in the listbox to see that image."
}
msg.pack('side'=>'top')

# frame
TkFrame.new($image3_demo) {|frame|
  TkButton.new(frame) {
    text 'Dismiss'
    command proc{
      tmppath = $image3_demo
      $image3_demo = nil
      tmppath.destroy
    }
  }.pack('side'=>'left', 'expand'=>'yes')

  TkButton.new(frame) {
    text 'Show Code'
    command proc{showCode 'image3'}
  }.pack('side'=>'left', 'expand'=>'yes')

}.pack('side'=>'bottom', 'fill'=>'x', 'pady'=>'2m')

# variable
$dirName = TkVariable.new([$demo_dir,'..','images'].join(File::Separator))

# image
begin
  $image3a.delete
rescue
end
$image3a = TkPhotoImage.new

#
image3_f = TkFrame.new($image3_demo).pack(:fill=>:both, :expand=>true)

image3_df = TkLabelFrame.new($image3_demo, :text=>'Directory:')

image3_ff = TkLabelFrame.new($image3_demo, :text=>'File:', 
                             :padx=>'2m', :pady=>'2m')
image3_lbx = TkListbox.new(image3_ff, :width=>20, :height=>10) {
  pack(:side=>:left, :fill=>:y, :expand=>true)
  yscrollbar(TkScrollbar.new(image3_ff).pack(:side=>:left, :fill=>:y, 
                                             :expand=>true))
  insert(0, *(%w(earth.gif earthris.gif teapot.ppm)))
  bind('Double-1', proc{|x,y| loadImage(self, x, y)}, '%x %y')
}

image3_ent = TkEntry.new(image3_df, :width=>30, :textvariable=>$dirName){
  pack(:side=>:left, :fill=>:both, :padx=>'2m', :pady=>'2m', :expand=>true)
  bind('Return', proc{loadDir(image3_lbx)})
}

TkButton.new(image3_df, :pady=>0, :padx=>'2m', :text=>"Select Dir.", 
             :command=>proc{selectAndLoadDir(image3_ent, image3_lbx)}) {
  pack(:side=>:left, :fill=>:y, :padx=>[0, '2m'], :pady=>'2m')
}

image3_if = TkLabelFrame.new($image3_demo, :text=>'Image:') {|f|
  TkLabel.new(f, :image=>$image3a).pack(:padx=>'2m', :pady=>'2m')
}

Tk.grid(image3_df,  '-',
        :sticky=>:ew, :padx=>'1m', :pady=>'1m', :in=>image3_f)
Tk.grid(image3_ff, image3_if, 
        :sticky=>:nw, :padx=>'1m', :pady=>'1m', :in=>image3_f)
TkGrid.columnconfigure(image3_f, 1, :weight=>1)