Forum: Ruby-Gnome 2 problem drawing rectangle

Hi,
I'm having difficulties drawing a rectangle in a drawingarea (in a
table). New to ruby-gnome, i'm trying some stuff out. This is what i
tried (rectangle should be in the big blue area):
require 'gtk2'

window = Gtk::Window.new
window.border_width = 10
window.set_default_size(1200,800)
window.set_window_position(1)
window.title = "xxxx"
window.signal_connect('delete_event') { false }
window.signal_connect('destroy') { Gtk.main_quit }

table = Gtk::Table.new(15, 15, true)
window.add(table)
label = Gtk::Label.new("Hello world")
color = Gdk::Color.parse("#003366")
color2 = Gdk::Color.parse("#8295A8")
label.modify_fg(Gtk::STATE_NORMAL, color)
eb = Gtk::EventBox.new()
eb.add(label)
eb.modify_bg(Gtk::STATE_NORMAL, color2)
button = Gtk::Button.new('click!')
table.attach_defaults(button, 10, 11, 1, 2)
table.attach_defaults(eb, 0, 8, 0, 1)
button.signal_connect('clicked') do
  label.text = "changed"
end
eb2 = Gtk::EventBox.new()
eb2.modify_bg(Gtk::STATE_NORMAL, color2)
table.attach_defaults(eb2, 0, 12, 2, 15)
button1 = Gtk::Button.new("Pixel by pixel ...")
button2 = Gtk::Button.new("you choose my fate")
slabel1 = Gtk::Label.new("test")
fixed = Gtk::Fixed.new
#fixed.put(button1, 0, 0)
#fixed.put(button2, 20, 30)
fixed.put(slabel1, 100, 150)
eb2.add(fixed)
area = Gtk::DrawingArea.new
area.set_size_request(50,50)
area.signal_connect("expose_event") do
  alloc = area.allocation
  area.window.draw_rectangle(area.style.fg_gc(area.state), true,
                       100, 0, 100, 100)
end
table.attach_defaults(area, 0, 12, 2, 15)
window.show_all
Gtk.main

hi Kelly,

  your rectangle is there, it's just under the giant 'test' label... 
try this:

require 'gtk2'

window = Gtk::Window.new
window.set_default_size(500,300)
window.signal_connect('destroy') { Gtk.main_quit }

eb = Gtk::EventBox.new()
  label = Gtk::Label.new("Hello world")
  color = Gdk::Color.parse("#003366")
  color2 = Gdk::Color.parse("#8295A8")
  label.modify_fg(Gtk::STATE_NORMAL, color)
eb.add(label)
eb.modify_bg(Gtk::STATE_NORMAL, color2)

button = Gtk::Button.new('click!')
button.signal_connect('clicked') do
  label.text = "changed"
end

eb2 = Gtk::EventBox.new()
eb2.set_size_request(100, 100)
eb2.modify_bg(Gtk::STATE_NORMAL, color2)
  slabel1 = Gtk::Label.new("test")
  slabel1.set_size_request(100, 100)
eb2.add(slabel1)

area = Gtk::DrawingArea.new
area.signal_connect("expose_event") do
  alloc = area.allocation
  area.window.draw_rectangle(area.style.fg_gc(area.state), true,
  20, 0, 100, 100)
end

table = Gtk::Table.new(3, 3, true)
table.attach_defaults(button, 0, 1, 0, 1)
table.attach_defaults(eb, 1, 2, 0, 1)
table.attach_defaults(eb2, 0, 1, 1, 2)
table.attach_defaults(area, 1, 2, 1, 2)

window.add(table)
window.show_all
Gtk.main

  ...and then play around with the dimensions, adding more rows and 
columns, widgets, etc...

  hth -

  - j

hey Kelly,

> ...(rectangle should be in the big blue area):

  sorry, just noticed this bit!  i don't think you can add a drawing 
area on top of a label - i'm not at home now, but try putting the label 
and the drawing area rectangle in a fixed layout and then add that 
layout to the table (sort of like you were.)  make sure to place the 
label in the layout first, and then the drawing area on top of it, 
otherwise you won't see the rectangle (like what was happening with your 
original code.)

  give it a shot, and get back with any questions - i'll give it a try 
when i can too ;)

  good luck

 - j

Thanks for the quick help jake.
My intention is to be able to show both drawings and labels in this
eventbox(eb2), and even to be able to show the colored rectangle behind 
the
label. I'm wondering if these things are even possible tho. The lack of
detailed tutorials and manuals isn't helping either..

hi Kelly,

> My intention is to be able to show both drawings and labels in this
> eventbox(eb2), and even to be able to show the colored rectangle behind
> the label.

  hmm...  i tried putting a label on top of a rectangle drawn in a
drawing area, and couldn't get it to work - there's probably a way
(anyone?)

  i usually draw directly onto an EventBox...  DrawingArea's give me
problems :P

  the nice thing about drawing directly onto an EventBox, is that you
can call #set_visible_window(false) on the EventBox, and have a
transparent background.  you can also catch all kinds of signals with no
problem.

  if what you want is to show some text on top of a rectangle that
you've drawn, and connect that rectangle to button clicks, you could do
something like this:

<code>
require 'gtk2'

win = Gtk::Window.new
win.signal_connect("destroy"){Gtk.main_quit}
win.set_size_request(600, 400)

layout = Gtk::Layout.new

  @my_label = ["first i say this...", "then i say the other..."]
  @index = 0

  @ebox = Gtk::EventBox.new
  @ebox.set_size_request(250, 80) # this is important!
  @ebox.signal_connect("button-press-event"){redraw_my_label}
  @ebox.signal_connect("expose-event"){
    @cc = @ebox.window.create_cairo_context
    @cc.set_source_color(Gdk::Color.parse("#003366"))
    @cc.rectangle(0, 0, 250, 80) # notice the ebox is the same size...
    @cc.fill
    @cc.select_font_face("Purisa", Cairo::FONT_SLANT_NORMAL,
      Cairo::FONT_WEIGHT_NORMAL)
    @cc.set_font_size 13
    @cc.set_source_rgb(250, 250, 250)
    @cc.move_to(35, 30)
    @cc.show_text(@my_label[@index])
  }

layout.put(@ebox, 0, 0)

def redraw_my_label
  @index += 1; @index = 0 if @index > 1
  @cc.show_text(@my_label[@index])
  @ebox.queue_draw # .queue_draw sends the 'expose-event' signal
end

win.add(layout)
win.show_all
Gtk.main
</code>


  ...you could now stick this layout into a table with whatever other
widgets you want.  is this something like what you're looking for?  hope
so!

> The lack of detailed tutorials and manuals isn't helping either..

  gtk2 is actually (and unfortunately) one of the best documented gui
toolkits i've found - go figure ;)    that said, it's still kind of a
pain in the arse at times - don't get discouraged.  just fool around a
bunch and you'll get the hang of it.  i've found that when i'm wondering
what a particular widget can do a quick

  #.methods.sort.each{|method| p method}

  ...gives me a good idea of what a widget can do, or at least a place
to start googling!

  - j

That is what i am trying to do indeed. I'm getting an error tho, when i
click  the eventbox:
rectangle.rb:32:in `show_text': the target surface has been finished
         from rectangle.rb:32:in `redraw_my_label'
         from rectangle.rb:14
         from rectangle.rb:38:in `call'
         from rectangle.rb:38:in `main'
         from rectangle.rb:38

Kelly Pfaff wrote in post #1041658:
> I'm getting an error tho, when i
> click  the eventbox:
> rectangle.rb:32:in `show_text': the target surface has been finished
>          from rectangle.rb:32:in `redraw_my_label'
>          from rectangle.rb:14
>          from rectangle.rb:38:in `call'
>          from rectangle.rb:38:in `main'
>          from rectangle.rb:38

  hmm...  what version of ruby and of gtk are you using?  what platform 
are you on?  i'm using ruby 1.9.3 with gtk2 1.0.3 (still need to update) 
under ubuntu 10.04 lts - and it works for me...

  anyone else have any ideas what's going on?

  - j

jake kaiden wrote in post #1041683:
>   hmm...  what version of ruby and of gtk are you using?  what platform
> are you on?  i'm using ruby 1.9.3 with gtk2 1.0.3 (still need to update)
> under ubuntu 10.04 lts - and it works for me...
>
>   anyone else have any ideas what's going on?

I tried your example with 1.9.3/1.1.0 and 1.8.7/1.0.3 and it works on 
both. So I have no ideas.

The error seems to come from cairo 
http://cairographics.org/manual/cairo-Error-handling.html .

Simon