Volume bars
can be oriented either horizontally or vertically. It is essentially a track
in which an optional slider can move about for displaying an analogue representation
of the volume. The track is filled with a coloured bar either from the left or from the
bottom indicating the volume level along with the position of the slider. This is the
only style of interactive volume control. By touching a position in the track, the slider
can be moved or dragged to a new position. Commands will be sent to the specified
zone or appropriate device to set the level.
Image 10 - Volume bar style
Volume read-outs
show the level in digital form. They are not interactive but can
be used in combination with a volume bar for providing control along with an
analogue and a digital display of the volume. They can alternatively be used
alongside two buttons for increasing and decreasing the volume as shown below.
Image 11 - Volume read-out with buttons for volume increase and decrease
Volume controls have the following properties:
Mode
chooses the style of the volume control. Available options are “Horizontal
volume bar”, “Vertical volume bar” and “Volume read-out”. The selected mode must
correspond to the look of the frame image. Changing the mode does not change the
image's appearance.
Zone
and
Amp
/
Preamp
must be defined since the control otherwise can have no
purpose (unless the volume control is assigned to an applet). However the zone
property can just be left set to “(page)” if the page has a zone setting. A zone may
be explicitly set in the volume control in order to control multiple zones within a
single page.
Global
is used for making the volume control appear in every page in the
configuration. This is useful if all the pages have some volume controls in common.
The individual instances of the volume controls can be edited or deleted after the
global setting has been set.
Display area
is used for setting up the rectangle for the track on volume bars or for
the area where digits are displayed on volume read-outs.
Volume controls can be used in combination with certain applets for controlling and
displaying various analogue quantities such as the dimming level in a lighting system. To
assign a volume control to an applet, it must be placed completely inside of the applet's
window in the page designer.
Volume Image Components
Volume controls are composed of two image components:
The “Frame” image is basically the back of the control. Volume bars should have an
area where the track will be displayed and volume read-outs need a large enough
area for displaying the digits. Volume bar frame images must be at least as wide as
the slider image so that “droppings” are not left on the background by the slider
when it moves. If the frame is to appear narrower than the slider (as shown by the
volume bar example above), transparency is used in the frame image to make it
seem narrower than it actually is. Transparent areas are re-drawn when the slider is
moved ensuring a proper update of the affected area.
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