Chapter 5. Content objects

Chapter 5. Content objects
	Part II. Reference

XXE_install_dir/demo/forms/form-sampler.xml is used to demo how standard controls such as buttons, check boxes, combo boxes, text fields, etc, can be embedded in the styled view. The CSS style sheets used by this demo are found in sub-directory XXE_install_dir/demo/forms/form-sampler/.

Most pseudo-functions create objects which can be styled at the object level. Styles are specified using key, value pairs where key is the name of a style property (example: font-size) and value is the value of a style property (example: smaller).

Example:

text-field(columns, 10,
           background-color, white,
           color, black)

The default font and colors of content objects such as check-box, combo-box, etc

	The default font and colors of content objects such as `check-box`, `combo-box`, etc
The value of CSS property `font` is inherited from the style of the element for which the content object is generated. The value of CSS property `background-color` is not inherited. A content object has an intrinsic background color which comes from the Java™ “Look & Feel” used for the XML editor. If a solid `background-color` has been explicitly specified for the content object or if the content object is intrinsically transparent (`radio-buttons`, `check-box`), then the value of CSS property `color` is inherited from the style of the element for which the content object is generated. Otherwise, the content object has an intrinsic foreground color which comes from the Java “Look & Feel” used for the XML editor.

The value of CSS property font is inherited from the style of the element for which the content object is generated.
The value of CSS property background-color is not inherited. A content object has an intrinsic background color which comes from the Java™ “Look & Feel” used for the XML editor.
If a solid background-color has been explicitly specified for the content object or if the content object is intrinsically transparent (radio-buttons, check-box), then the value of CSS property color is inherited from the style of the element for which the content object is generated.
Otherwise, the content object has an intrinsic foreground color which comes from the Java “Look & Feel” used for the XML editor.

Shorthand properties cannot be used to specify style parameters as described above.
Example: padding-top, padding-left, padding-bottom, padding-right must be used rather than the single shorthand property padding.
The above example is conceptually equivalent to (illegal CSS):
```
{ text-field(columns, 10);
  background-color: white;
  color: black; }
```
It is important to keep this is mind because it explains why you can specify:
```
text-field(columns, attr(cols),
           background-color, white,
           color, black)
```
but not:
```
text-field(columns, 10,
           background-color, white,
           color, attr(foreground))
```
The attr() construct can only be used in the value of property content: therefore it is not possible to specify "color: attr(foreground);".

All pseudo-functions generating controls (text-field, list, etc) also support the following color specifications:

Key	Value	Default	Description
missing-color	Color	rgb(0,128,128)	Foreground color used by the control when attribute or element value is missing. Therefore, this color is used when drawing default value.
missing-background-color	Color	None (no special background color)	Background color used by the control when attribute or element value is missing. Therefore, this color is used when drawing default value.
error-color	Color	rgb(128,0,0)	Foreground color used by the control when attribute or element value is invalid or when control is not well suited to edit this kind of value.
error-background-color	Color	None (no special background color)	Background color used by the control when attribute or element value is invalid or when control is not well suited to edit this kind of value.

Example:

text-field(columns, 10,
           missing-color, gray)

All pseudo-functions generating content (except icon() and xpath()) accept attr() and xpath() values as well as literal values for their parameters.
Example:
```
text-field(columns, 10)

text-field(columns, attr(cols))

text-field(columns, xpath("5 + 5"))
```
Most pseudo-functions are shorthand notations for gadget(interface_name). See gadget.
For example, collapser() is a shorthand notation for gadget("com.xmlmind.xmledit.cssext.Collapser"), command-button() is a shorthand notation for gadget("com.xmlmind.xmledit.cssext.edit.CommandButton"), etc.