Development/Tutorials/Plasma/Ruby/Using widgets - Revision history

Neverendingo: Text replace - "" to ""

2011-06-29T20:54:25Z

Text replace - "</code>" to "</syntaxhighlight>"

Neverendingo: Text replace - "`" to ""`


2011-06-29T20:42:45Z
Text replace - "<code ruby>" to "<syntaxhighlight lang="ruby">"

				
				
				
				
			
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			Revision as of 20:42, 29 June 2011
			
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  Here is how our main.rb file will look like:   Here is how our main.rb file will look like:
    
− <code ruby> + <syntaxhighlight lang="ruby">
  # Copyright stuff   # Copyright stuff
  require 'plasma_applet'   require 'plasma_applet'



Tampakrap: /* Abstract */
2009-04-29T14:07:02Z
‎Abstract

				
				
				
				
			
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			Revision as of 14:07, 29 April 2009
			
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  == Abstract ==   == Abstract ==
    
− Using the <tt>paintInterface</tt> method to display applets is a powerful, and sometimes even necessary way of working. For example, when you want to display a SVG graphic. But it is not the only method available to create a Plasmoid, however. Plasma comes with a number of widgets "tailored" for use in Plasmoids. In this tutorial we will create a very simple "Hello, world!" Plasmoid using Plasma widgets. + Using the <tt>paintInterface</tt> method to display applets is a powerful, and sometimes even necessary way of working, like when you want to display a SVG graphic. It is not, however, the only method available to create a Plasmoid. Plasma comes with a number of widgets "tailored" for use in Plasmoids. In this tutorial we will create a very simple "Hello, world!" Plasmoid using Plasma widgets.
    
  == Prerequisites ==   == Prerequisites ==



Nielsslot: Small fix in example code.
2009-01-25T21:14:46Z
Small fix in example code.

				
				
				
				
			
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			Revision as of 21:14, 25 January 2009
			
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         label = Plasma::Label.new self          label = Plasma::Label.new self
         label.text = "Hello world!"          label.text = "Hello world!"
−        self.layout.add_item label +        layout.add_item label
         self.layout = layout          self.layout = layout
    



Nielsslot: Change module, and tell the reader to do this in de metadata.desktop file.
2009-01-25T21:09:21Z
Change module, and tell the reader to do this in de metadata.desktop file.

				
				
				
				
			
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			Revision as of 21:09, 25 January 2009
			
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  == Prerequisites ==   == Prerequisites ==
    
− Set up your applet directory and create a <tt>metadata.desktop</tt> file as described in the [[../GettingStarted | Getting Started tutorial]]. + Set up your applet directory and create a <tt>metadata.desktop</tt> file as described in the [[../GettingStarted | Getting Started tutorial]]. Don't forget to change the <tt>X-KDE-PluginInfo-Name</tt> line to match the module used in the tutorial (<tt>RubyWidget</tt>), otherwise the example will not work!
    
  == The 'main.rb' file ==   == The 'main.rb' file ==
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  require 'plasma_applet'   require 'plasma_applet'
    
− module RubyStart + module RubyWidget
     class Main < PlasmaScripting::Applet      class Main < PlasmaScripting::Applet
       def initialize parent        def initialize parent



Nielsslot: Forgot to change one '.py' to '.rb'
2009-01-25T21:07:52Z
Forgot to change one '.py' to '.rb'

				
				
				
				
			
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			Revision as of 21:07, 25 January 2009
			
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  == The 'main.rb' file ==   == The 'main.rb' file ==
    
− Here is how our main.py file will look like: + Here is how our main.rb file will look like:
    
  <code ruby>   <code ruby>



Nielsslot: Translation of the Python 'Using widgets' tutorial. I removed the lines about the SVG theme because it didn't seem to do anything, feel free to correct me.
2009-01-25T21:07:15Z
Translation of the Python 'Using widgets' tutorial. I removed the lines about the SVG theme because it didn't seem to do anything, feel free to correct me.
New page
This is a 'translation' of the Using widgets article on Python and Plasma. For the Python Tutorial see [http://techbase.kde.org/Development/Tutorials/Plasma/Python/Using_widgets here].



== Abstract ==



Using the <tt>paintInterface</tt> method to display applets is a powerful, and sometimes even necessary way of working. For example, when you want to display a SVG graphic. But it is not the only method available to create a Plasmoid, however. Plasma comes with a number of widgets "tailored" for use in Plasmoids. In this tutorial we will create a very simple "Hello, world!" Plasmoid using Plasma widgets.



== Prerequisites ==



Set up your applet directory and create a <tt>metadata.desktop</tt> file as described in the [[../GettingStarted | Getting Started tutorial]].



== The 'main.rb' file ==



Here is how our main.py file will look like:



<code ruby>

# Copyright stuff

require 'plasma_applet'



module RubyStart

  class Main < PlasmaScripting::Applet

    def initialize parent

      super parent

    end



    def init

      self.has_configuration_interface = false

      self.aspect_ratio_mode = Plasma::Square

      self.background_hints = Plasma::Applet.DefaultBackground



      layout = Qt::GraphicsLinearLayout.new Qt::Horizontal, self

      label = Plasma::Label.new self

      label.text = "Hello world!"

      self.layout.add_item label

      self.layout = layout



      resize 125, 125

    end

  end

end

</code>



Let's take a deeper look at it. As in the main tutorial, we create our class by deriving from the <tt>PlasmaScripting::Applet</tt> class. In <tt>initialize</tt>, we quickly initialize the class. We use the <tt>init</tt> method instead to do all the dirty work of creating the applet and adding the widget needed to display the text.



First of all we tell Plasma that this applet does not have a configuration dialog (<tt>has_configuration_interface=</tt>). We then set the aspect ratio mode to a square (<tt>Plasma::Square</tt>). This is taken into account when someone resizes the applet. Next the <tt>background_hints=</tt> method sets the Plasmoid's background to the default Plasma background (<tt>Plasma::Applet.DefaultBackground</tt>) saving us from having to manually draw the background ourselves.



The third and most important step deals with creating a layout. It is a bit different than the standard <tt>Qt::LinearLayout</tt> seen in Qt, because it is done inside a <tt>Qt::GraphicsView</tt> used by Plasma. We want a simple, linear layout, and so we use a <tt>Qt::GraphicsLinearLayout</tt>, setting it to be horizontal (<tt>Qt::Horizontal</tt>).



Next we create a <tt>Plasma::Label</tt>. This is a widget that is Plasma aware and therefore uses all of the goodies provided by Plasma. For example, automatically changing its text color if the Plasma theme changes. We then use the <tt>text=</tt> method (analogous to the normal <tt>Qt::Label.text=</tt> method) to set our label text ("Hello, world!") and then add the label to the layout. Also, we set the applet's layout to be the one we have just defined using <tt>self.layout=</tt>. Finally we resize the applet to 125 x 125 pixels. 



Once packaged and installed (see [[../GettingStarted | the Getting Started tutorial]]), the Plasmoid will look like this:



[[Image:Helloworld.png|center]]



== Conclusion ==



This brief tutorial shows how to use Plasma widgets with your applet. Beside <tt>Plasma::Label</tt> there are many more widgets that you can use.



Notice that at the moment you can only add widgets and create layouts directly in code. This means you can't use an application like Qt Designer to design the appearance of your applet.

@@ Line 38: / Line 38: @@
    end
 end
-</code>
+</syntaxhighlight>
 Let's take a deeper look at it. As in the main tutorial, we create our class by deriving from the <tt>PlasmaScripting::Applet</tt> class. In <tt>initialize</tt>, we quickly initialize the class. We use the <tt>init</tt> method instead to do all the dirty work of creating the applet and adding the widget needed to display the text.