Tips and Tricks

This section contains general Tips and Tricks when working with gui4j.

KeyMaps
Inline keyMaps directly into your GUI description with any special settings (i.e. keyboard shortcuts for button execution on specific keys), but place generic keyMaps like setting TAB to ENTER in a table to a common included XML file (e.g. templates/keyMaps.xml).
This will increase reusability of general definitions.
Styles
Instead of declaring attributes in every element of a specific form, exclude these common attributes and place them in a extra file (i.e. config/styles.xml). Include this file by use of a Include.
Layout
It is useful to work with low nesting depths. When doing complex layouts, the XML-structure might become difficult to read. So only declare real GUI components only if they require one or two lines. Otherwise use the id attribute as seen on all layouting placing elements (e.g. borderLayout's placeBl) or the Ref element to declare a reference to another GUI component.

GUI templates
When the same component structure or layout is used several times in an application, it can be extracted to a separate file and be defined only once.
The following example shows a simple, but useful layout:

File tabledialog.xml:

<View>
	<Param id="table" />	
	<Param id="tablebuttons" />	
	<Param id="buttons" />		
	<Param id="header" />			
	<Include url="../config/styles.xml" alias="styles"/>
	<!-- -->	
	<!-- Layout -->
	<borderLayout guiId="top">
		<placeBl anchor="north" id="header"/>				
		<placeBl anchor="center" id="tableandbuttons" />
		<placeBl anchor="south" id="buttonrow"/>				
	</borderLayout>	
	<!-- -->	
	<!-- Buttonrow -->		
	<borderLayout guiId="buttonrow">
		<placeBl anchor="east" id="buttons"/>
	</borderLayout>
	<!-- -->	
	<!-- Table and Buttons-->		
	<borderLayout guiId="tableandbuttons" >
		<placeBl anchor="center" id="table"/>
		<placeBl anchor="east" id="tablebuttonrow"/>
	</borderLayout>
	<!-- -->	
	<!-- Table Buttons -->
	<borderLayout guiId="tablebuttonrow">
		<placeBl anchor="north" id="tablebuttons"/>
	</borderLayout>
	<!-- -->
</View>

file: tabledialog.xml

GUI example of XML-description

Note: The tabledialog.xml only does layouting. This picture shows a GUI with components. The components have only been integrated to give width and hight to the layout.

As you can see, by use of the Param element, four parameters are defined. To use this layout definition you simply include it in your GUI definition and define the parameter values:

<View top="layout/top">
	<Include url="tabledialog.xml" alias="layout">
		<Arg id="myTable" param="table"/>
		<Arg id="myTablebuttons" param="tablebuttons"/>
		<Arg id="myButtons" param="buttons"/>
		<Arg id="myHeader" param="header"/>		
	</Include>
	[...]
	<table guiId="myTable" [...] >
		[...]
	</table>
	[...]
</View>

The tabledialog.xml file is included and four components ("myTable" etc.) are mapped to the layout template's parameters.
The layout is used by defining it's "top" component (fully qualified as "layout/top") as the top component of your <View>.