Eclipse Form Programming Guide (3)

Program | design
4. Complex controls

(1) Expandablecomposite

L A common theme in Web pages is the ability to shrink part of a page's content







L The Eclipse form also provides such a control: Expandablecomposite







L The following code fragment is an example of using Expandablecomposite:







Expandablecomposite EC = toolkit.createexpandablecomposite (Body,



Expandablecomposite.tree_node



| Expandablecomposite.client_indent);



Ec.settext ("Expandable composite title");



String Ctext = "We'll now create a somewhat long text"



+ "We can use it as content for the expandable composite."



+ "Expandable composite is used to hide or show the text using the"



+ "Toggle Control";



Label client = Toolkit.createlabel (EC, Ctext, SWT. WRAP);



Ec.setclient (client);



td = New Tablewrapdata ();



Td.colspan = 2;



Ec.setlayoutdata (TD);



Ec.addexpansionlistener (New Expansionadapter () {



public void expansionstatechanged (Expansionevent e) {



Form.reflow (TRUE);



}



});



L This control has many styles, Tree_node makes the control have the expand and shrink function of the tree node, and Twistie makes the control have the Triangle arrow style







L expanded makes initial expansion display







L Client_indent makes the CLIENT content indent







L Expandablecomposite is rendered as activating control and caption, while the contents that can be expanded and shrunk are called client







L Client must be expandable composite (the previous example is a Label control)







L finally need to add expansion listener when the state changes, the Reflow Form (that is, reposition and update the scroll bar based on the new size of the control)







L The following is the result of the operation of the previous example:





(2) Section







The most common custom control in the Eclipse form is the section (visible everywhere in the PDE)







L section extension Expandablecomposite, but has the following new features:







n There is a separate control under the heading







n You can have a descriptive text below the separator control







L The following code snippet is an example of using a section, the code is not much different from the expandablecomposite, and here is the Twistie style:







Section section = toolkit.createsection (Body, section.description



| Section.twistie | section.expanded);



td = New Tablewrapdata (Tablewrapdata.fill);



Td.colspan = 2;



Section.setlayoutdata (TD);



Section.addexpansionlistener (New Expansionadapter () {



public void expansionstatechanged (Expansionevent e) {



Form.reflow (TRUE);



}



});



Section.settext ("section title");



Toolkit.createcompositeseparator (section);



Section



. SetDescription ("This is the description that goes below the title");



Composite sectionclient = toolkit.createcomposite (section);



Sectionclient.setlayout (New GridLayout ());



button = Toolkit.createbutton (Sectionclient, "Radio 1", SWT. RADIO);



button = Toolkit.createbutton (Sectionclient, "Radio 2", SWT. RADIO);



Section.setclient (sectionclient);



L The following is the result of the operation of the previous example: