fxruby-users

[Fxruby-users] Segmentation fault when changing the icon for a button

[Carsten E. <ca...@ci...>]

Hi,

I'm banging my head against this problem for days now: I have a button 
which displays an icon and then when the button is pressed it should 
display another icon. So the first icon is displayed fine but when I 
press the button the app chrashes with a segmentation fault. I'm testing 
this with the 'Pragmatic Installer 1.8.0-10' on Windows 2000.

Here's the code:
#------------------------------------------

require 'fox'
include Fox
class MainWindow < FXMainWindow
  # load a png image from file
  def loadIcon(filename)
    begin
      icon = nil
      File.open(filename+".png", "rb") { |f|
        icon = FXPNGIcon.new(getApp(), f.read)
      }
      icon
    rescue
      raise RuntimeError, "Couldn't load icon: #{filename}"
    end
  end
  # initialize the window
  def initialize(app)
    super(app, "Test", nil, nil, DECOR_ALL, 0, 0, 0,0, 0, 0)
    button = FXButton.new(self,"")
    # set the buttons icon to the first image -> works well.
    button.icon = loadIcon("first")
    # when the button is pressed, change the icon
    # to the second image -> BOOM!
    button.connect(SEL_COMMAND) { button.icon = loadIcon("second") }
    end
  # create the window
  def create
    super
    show(PLACEMENT_SCREEN)
  end
end
# create and run the application
app = FXApp.new("Test", "Test")
MainWindow.new(app)
app.create
app.run
#------------------------------------------

It also doesn't work for FXlabel and FXImageView. What am I doing wrong 
here?????? Help!

Carsten.

Re: [Fxruby-users] Segmentation fault when changing the icon for a button

[Bil <bi...@vi...>]

Carsten,

You need to icon.create before you return icon from loadIcon (or at least,=
 before you use button.icon=3D). The reason is that MainWindow.create calls=
 icon.create for "first" icon as it a 'grand-child' of MainWindow at the=
 moment that MainWindow is created. The "second" icon you load up later=
 will need to be 'create'd manually before use. It doesn't matter if you=
 create something too many times (I think it is just ignored), as long as=
 it is done at least once before you attempt to use it.

bil

*********** REPLY SEPARATOR  ***********

On 08/12/2003 at 19:40 Carsten Eckelmann wrote:

>Hi,
>
>I'm banging my head against this problem for days now: I have a button 
>which displays an icon and then when the button is pressed it should 
>display another icon. So the first icon is displayed fine but when I 
>press the button the app chrashes with a segmentation fault. I'm testing 
>this with the 'Pragmatic Installer 1.8.0-10' on Windows 2000.
>
>Here's the code:
>#------------------------------------------
>
>require 'fox'
>include Fox
>class MainWindow < FXMainWindow
>  # load a png image from file
>  def loadIcon(filename)
>    begin
>      icon =3D nil
>      File.open(filename+".png", "rb") { |f|
>        icon =3D FXPNGIcon.new(getApp(), f.read)
>      }
>      icon
>    rescue
>      raise RuntimeError, "Couldn't load icon: #{filename}"
>    end
>  end
>  # initialize the window
>  def initialize(app)
>    super(app, "Test", nil, nil, DECOR_ALL, 0, 0, 0,0, 0, 0)
>    button =3D FXButton.new(self,"")
>    # set the buttons icon to the first image -> works well.
>    button.icon =3D loadIcon("first")
>    # when the button is pressed, change the icon
>    # to the second image -> BOOM!
>    button.connect(SEL_COMMAND) { button.icon =3D loadIcon("second") }
>    end
>  # create the window
>  def create
>    super
>    show(PLACEMENT_SCREEN)
>  end
>end
># create and run the application
>app =3D FXApp.new("Test", "Test")
>MainWindow.new(app)
>app.create
>app.run
>#------------------------------------------
>
>It also doesn't work for FXlabel and FXImageView. What am I doing wrong 
>here?????? Help!
>
>Carsten.
>
>
>
>
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