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<h2><font face="Helvetica, Arial, sans-serif">Visual Inheritance and custom class properties.</font></h2>
<big><b><br>
</b></big><big><small><font face="Helvetica, Arial, sans-serif">Note: We will use
"custom" here to mean any visual class which is an extension of a Swing or
SWT class, but is not in the Swing or SWT packages.<br>
<br>
<b><i><u>Visual Inheritance</u></i></b><br>
</font></small></big><big><small><font face="Helvetica, Arial, sans-serif">Jigloo
supports visual inheritance, in that it allows you to edit visual
classes which extend other visual custom classes (eg, if you create
MyComposite1 which extends org.eclipse.swt.widgets.Composite, then you
can create and edit MyComposite2 which extends MyComposite1).<br>
<br>
As long as the custom superclass is public and not abstract, then Jigloo can manage </font></small></big><big><small><font face="Helvetica, Arial, sans-serif">abstract any kind of subclass (public, private, package-access, abstract, etc)</font></small></big><big><small><font face="Helvetica, Arial, sans-serif">.<br>
</font></small></big><font face="Helvetica, Arial, sans-serif"><br>
Jigloo can also manage public, non-abstract classes which extend
abstract or non-public custom superclasses, but a small change needs to
be made to the subclass - this is discussed in <a href="#abstract">this section.</a></font><br>
<b><u><i><font face="Helvetica, Arial, sans-serif"></font></i></u></b><br>
<big><small><font face="Helvetica, Arial, sans-serif">Continuing with
the above example, if MyComposite1 contains a publically-accessible
Group, or has a public getter method for the Group, then you will be
able to edit that inherited Group in MyComposite2. You can change it's
properties, add event listeners to it, and also add other widgets to it.</font></small></big><br>
<p style="font-family: arial;"><b>Note:</b> Jigloo is <b><i>not</i> </b>able to handle inherited protected fields or methods, since it cannot access protected objects.<br>
</p><p style="font-family: arial;">Any changes you make to a superclass
will be picked up by the subclasses <i><b>after the changes are saved</b></i>,
and
the changes will be apparent in Jigloo. In some cases, however, the
changes will only become visible when the subclass is reloaded by using
the "Reload Form Editor" right-click menu option in the Form Editor.<br>
<br>
<b><u><i><font face="Helvetica, Arial, sans-serif">Custom class properties</font></i></u></b><br>
</p>
<p style="font-family: arial;">Besides allowing you to edit inherited elements, Jigloo is also able to allow you to manipulate <font face="Helvetica, Arial, sans-serif">publically-accessible
fields of custom classes added to the main class. This is discussed <a href="#custom">here.</a></font><br>
</p>
<p style="font-family: arial;"><b><big><br>
<a name="creating"></a>Creating a subclass of a custom visual class</big></b><br>
</p>
<p style="font-family: arial;">To create a subclass of an
existing custom class, start by creating a GUI class in the usual way using
Jigloo. See <a href="getting_started.html#new_class">"Creating a new GUI"</a> for details if you are not familiar.<br>
</p>
<p style="font-family: arial;">You will get
the Jigloo New Wizard as usual, but instead of accepting the offered
"superclass" field, hit "Browse" and select the desired superclass.<br>
</p>
<p style="font-family: arial;"><img src="images/newForm3.PNG" title="" alt="" width="499" height="499"></p>
<p style="font-family: arial;"><br>
If the superclass is abstract, then Jigloo will automatically insert
stub implementations of all
abstract methods of the superclass. In addition, if the superclass is
abstract and/or non-public, then Jigloo will insert the necessary
methods to enable Jigloo to manage the class - see <a href="#abstract">this section</a> for more details.<br>
</p>
<p style="font-family: arial;"><br>
<big><b><a name="custom"></a>Editing properties of custom classes added to the other classes</b></big><br>
</p>
<p style="font-family: arial;">Besides allowing you to edit inherited elements, Jigloo is also able to allow you to manipulate <font face="Helvetica, Arial, sans-serif">publically-accessible
fields of custom classes added to the main class. For example, if you
create a
JPanel (eg, FlowerPanel) which has a publically-accessible JTextField,
and you add that FlowerPanel (as a custom class) to another visual
class inside a Jigloo
editor, then you will be able to manipulate (change properties of, add
event listeners to etc.) that </font><font face="Helvetica, Arial, sans-serif">JTextField</font><font face="Helvetica, Arial, sans-serif">.<br>
</font></p>
<p style="font-family: arial;"><font face="Helvetica, Arial, sans-serif">If,
for example, you edit the FlowerPanel in Jigloo and save your changes,
then the new FlowerPanel class will be re-loaded by any Jigloo editor
which uses a FlowerPanel as one of it's elements. You can experiment
with this using the FlowerShop example below.<br>
</font></p>
<p style="font-family: arial;"><font face="Helvetica, Arial, sans-serif"><br>
<big><b><a name="example"></a>Working with an example</b></big><br>
</font></p>
<p style="font-family: arial;">To play with an existing example, create
a new "GUI
Form->Examples->Swing Inheritance/JavaBean (FowerShop) Example"
which will insert several classes
into your project (you might want to create a new "flowershop" package
for them. The forms are FlowerPanel, ShopFrame, and a subclass of
ShopFrame called FlowerShop, plus classes to demonstrate Jigloo's
handling of JavaBean features - custom editors, customizers and
BeanInfo. When you create the example, FlowerShop
will be opened in Jigloo's form editor.<br>
</p>
<p style="font-family: arial;">FlowerShop demonstrates:<br>
</p>
<ul>
<li><font face="Helvetica, Arial, sans-serif">Manipulation of properties of inherited fields - for example, it sets the Border and LayoutManager on the inherited shopPanel</font></li>
<li><font face="Helvetica, Arial, sans-serif">Adding components to inherited fields - it adds four FlowerPanels to the inherited shopPanel</font></li>
<li><font face="Helvetica, Arial, sans-serif">Adding event listeners to inherited fields - it adds an ActionListener to the inherited "Checkout" button.</font></li>
<li><font face="Helvetica, Arial, sans-serif">Manipulating
publically-accessible fields of classes added to the main class - eg,
it sets the text properties of the "flowerLabel" field on each of the
four added FlowerPanels.</font></li>
</ul>
<p style="font-family: arial;">Below is a screen shot of the FlowerShop example. Note that in the Outline view, inherited fields are indicated by a blue icon <img src="images/inherited_dec.gif" title="" alt="" width="16" height="16">.
If the fields are inherited from a class which is an ancestor of
this class's superclass then the icon will be green (for example, if
JFrame1 has a public JButton called button1, and JFrame3 extends
JFrame2 which extends JFrame1, then in the Outline for JFrame3, button1
will have a green decorator icon.<br>
</p>
<p style="font-family: arial;">Note also the button at the top of the
Outline view with the same image - pressing this button will
alternately hide all inherited fields, will hide all fields not
directly inherited or will show all inherited fields, which can avoid
clutter in the Outline view.<br>
</p>
<p style="font-family: arial;">Note that, for example, a JScrollPane's
scrollbars will also show up as inherited fields, since they can be
accessed through public getter methods. Therefore, Jigloo allows you to
manipulate such objects easily (for example, enabling or disabling
them). <br>
</p>
<img src="images/jigloo_vert_split.PNG" title="" alt="" width="847" height="622"><br>
<p style="font-family: arial;"><br>
<a name="abstract"></a><big><b>Extending abstract and non-public classes<br>
<br>
</b></big>If a class extends an <small><i><big><b>abstract, private or package-access</b></big></i></small> class then Jigloo requires that the class implement a public static method called <i><b>getGUIBuilderInstance</b></i>
which should return an instance of the class which has not had it's GUI
elements initialized. <br>
</p>
<p style="font-family: arial;">Any classes created by Jigloo will automatically
have this method inserted (along with a constructor which does not call
initGUI), but if you wish to edit an existing class which extends an
abstract or non-public class then you should implement the <i><b>getGUIBuilderInstance</b></i>
yourself.<br>
</p>
<p style="font-family: arial;">This is an example for a Swing GUI,<br>
</p>
<p style="font-family: arial;"><small><tt> /**<br>
* This method should return an instance of this class which does <br>
* NOT initialize it's GUI elements. This method is ONLY required by<br>
* Jigloo if the superclass of this class is abstract. It is not needed<br>
* in any other situation.<br>
*/<br>
public static Object getGUIBuilderInstance() {<br>
return new NewJFrame(Boolean.FALSE);<br>
}<br>
<br>
/**<br>
* This constructor is used by the getGUIBuilderInstance method to<br>
* provide an instance of this class which has not had it's GUI elements<br>
* initialized (ie, initGUI is not called in this constructor).<br>
*/<br>
public NewJFrame(Boolean initGUI) {<br>
super();<br>
}</tt></small><br>
</p>
<p style="font-family: arial;">and this is one for an SWT GUI:<br>
</p>
<p style="font-family: arial;"><small><tt> /**<br>
* This method should return an instance of this class which does <br>
* NOT initialize it's GUI elements. This method is ONLY required by<br>
* Jigloo if the superclass of this class is abstract or non-public. It <br>
* is not needed in any other situation.<br>
*/<br>
public static Object getGUIBuilderInstance(<br>
org.eclipse.swt.widgets.Composite parent, int style) {<br>
return new NewComposite(parent, style, Boolean.FALSE);<br>
}<br>
<br>
/**<br>
* This constructor is used by the getGUIBuilderInstance method to<br>
* provide an instance of this class which has not had it's GUI elements<br>
* initialized (ie, initGUI is not called in this constructor).<br>
*/<br>
public NewComposite(org.eclipse.swt.widgets.Composite parent,<br>
int style, Boolean initGUI) {<br>
super(parent, style);<br>
}<br>
</tt></small><br>
</p>
<p style="font-family: arial;">In addition, if you use Jigloo to create an extension of an abstract class
then Jigloo will automatically insert stub implementations of all
abstract methods of the superclass.<br>
</p>
<p style="font-family: arial;"><br>
<br>
</p>
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