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Class org.w3c.css.aural.ACssVolume

java.lang.Object
   |
   +----org.w3c.css.properties.CssProperty
           |
           +----org.w3c.css.aural.ACssProperty
                   |
                   +----org.w3c.css.aural.ACssVolume

public class ACssVolume

extends ACssProperty

Value: <percentage> | silent | x-soft | soft | medium | loud | x-loud
Initial: medium
Applies to: all elements
Inherited: yes
Percentage values: relative to user-specified mapping

The legal range of percentage values is 0% to 100%. Note that '0%' does not mean the same as "silent". 0% represents the minimum audible volume level and 100% corresponds to the maximum comfortable level. There is a fixed mapping between keyword values and percentages:

• 'silent' = no sound at all, the element is spoken silently
• 'x-soft' = '0%'
• 'soft' = '25%'
• 'medium' = '50%'
• 'loud' = '75%'
• 'x-loud' = '100%'

Volume refers to the median volume of the waveform. In other words, a highly inflected voice at a volume of 50 might peak well above that. The overall values are likely to be human adjustable for comfort, for example with a physical volume control (which would increase both the 0% and 100% values proportionately); what this property does is adjust the dynamic range.

The UA should allow the values corresponding to 0% and 100% to be set by the listener. No one setting is universally applicable; suitable values depend on the equipment in use (speakers, headphones), the environment (in car, home theater, library) and personal preferences. Some examples:

• A browser for in-car use has a setting for when there is lots of background noise. 0% would map to a fairly high level and 100% to a quite high level. The speech is easily audible over the road noise but the overall dynamic range is compressed. Plusher cars with better insulation allow a wider dynamic range.
• Another speech browser is being used in the home, late at night, (don't annoy the neighbors) or in a shared study room. 0% is set to a very quiet level and 100% to a fairly quiet level, too. As with the first example, there is a low slope; the dynamic range is reduced. The actual volumes are low here, wheras they were high in the first example.
• In a quiet and isolated house, an expensive hi-fi home theatre setup. 0% is set fairly low and 100% to quite high; there is wide dynamic range.

The same authors stylesheet could be used in all cases, simply by mapping the 0 and 100 points suitably at the client side.

If an element has a volume of silent, it is spoken silently. It takes up the same time as if it had been spoken, including any pause before and after the element, but no sound is generated. This may be used in language teaching applications, for example. A pause is gdenerated for the pupil to speak the element themselves. Note: the value is inherited so child elements will also be silent. Child elements may however set the volume to a non-silent value and will then be spoken.

To inhibit the speaking of an element and all it's children so that it takes no time at all (for example, to get the effect of collapsing and expanding lists) use the CSS1 property 'display'

display: none

When using the rule display: none the element takes up no time; it is not represented as a pause the length of the spoken text.

ACssVolume()

Create a new ACssVolume

ACssVolume(CssExpression)

Creates a new ACssVolume

addToStyle(CssStyle)

Add this property to the CssStyle.

equals(CssProperty)

Compares two properties for equality.

get()

Returns the value of this property

getPropertyInStyle(CssStyle, boolean)

Get this property in the style.

getPropertyName()

Returns the name of this property

getValue()

Returns some usable value of this property... Deprecated.

isSoftlyInherited()

Returns true if this property is "softly" inherited e.g.

toString()

Returns a string representation of the object.

 public ACssVolume()

Create a new ACssVolume

 public ACssVolume(CssExpression expression) throws InvalidParamException

Creates a new ACssVolume

Parameters:

expression - The expression for this property

Throws: InvalidParamException

Values are incorrect

 public Object get()

Returns the value of this property

Overrides:

get in class CssProperty

 public boolean isSoftlyInherited()

Returns true if this property is "softly" inherited e.g. his value is equals to inherit

Overrides:

isSoftlyInherited in class CssProperty

 public float getValue()

Note: getValue() is deprecated.

Returns some usable value of this property...

 public String getPropertyName()

Returns the name of this property

Overrides:

getPropertyName in class CssProperty

 public String toString()

Returns a string representation of the object.

Overrides:

toString in class CssProperty

 public void addToStyle(CssStyle style)

Add this property to the CssStyle.

Parameters:

style - The CssStyle

Overrides:

addToStyle in class CssProperty

 public boolean equals(CssProperty property)

Compares two properties for equality.

Parameters:

property - The other property.

Overrides:

equals in class CssProperty

 public CssProperty getPropertyInStyle(CssStyle style,
                                       boolean resolve)

Get this property in the style.

Parameters:

style - The style where the property is

resolve - if true, resolve the style to find this property

Overrides:

getPropertyInStyle in class CssProperty

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