/**
\page  signal_browser_page Signal Browser

\tableofcontents

<br>

PSK and RTTY signals can be viewed in a multi-channel context.
You can open an embedded or a separate dialog to access the
browser.  These browsers can help to locate a signal of interest
on a busy band.  The browsers can be visible at any time, but are only
active when fldigi is in one of the PSK or RTTY modes.  Open the external
by clicking on the <b>View/Signal browser</b> menu item.
<br>

\image html view-menu.png "View Menu"
\image latex view-menu.png "View Menu" width=2.0in
<br>

It looks like this:
<br>

\image html browser-panel.png "Browser Panel"
\image latex browser-panel.png "Browser Panel" width=4.25in
<br>

Toggle the visibility of the embedded viewer by selecting the
<b><i>View/Hide Channels</i></b> on the same menu list.  Your main fldigi
screen then opens a browser panel on the left side of the Tx/Rx panel(s).
<br>

\image html main-dialog-browser.png "Main Dialog Browser"
\image latex main-dialog-browser.png "Main Dialog Browser" width=6.0in
<br>

This panel can be resized horizontally by dragging the interface between the
browser and the Rx panel to the left and right.  You can drag all the way to
the left to close the panel (or use the menu button).  The drag to the
right is limited to prevent sizing the Rx/Tx panels below their allowable
limits.
<br>

The browser can decode up to 30 simultaneous signals.  As each signal is
acquired within a 100 Hz channel width it is printed on the associated
line.  The user can elect to have each line annotated with
<br>

a channel number,<br>
the waterfall audio frequency,<br>
the transceiver HF frequency + waterfall, or<br>
no annotation.<br>
<br>

Left click on a line of received text to move the waterfall frequency
and Rx panel tracking to that signal.  The contents of the line of
text is transferred to the Rx text widget, and the main signal processing loop
begins to track and decode that signal.  Right click on a line of received
text and that line is cleared and the channel reset for a new
detection.  You may have to do this occasionally if the detector
for that channel has locked on to a sideband of a PSK signal.
This is most likely to occur when the received signal as a marginal or
bad IMD.  Use the ><b>Clear</b> button to clear and reset all of the
channels.  Channel signal detection and processing should restart
immediately.
<br>

Configuring the browser:
<br>

\image html config-ui-browser.png "Browser Configure"
\image latex config-ui-browser.png "Browser Configure" width=5.0in
<br>

<ol>
	<li>select the number of 100 Hz channels you want visible</li>
	<li>select the start frequency for the browser (your transceiver may not
	rx signals below this value)</li>
	<li>select the inactivity timeout for the browser.  After this
	number of seconds the channel will be cleared and prepared for the next
	detection cycle.</li>
	<li>select whether you want a Marque type of continuous scrolling, or simply
	clear the line when it is filled.</li>
	<li>select what kind of label annotation you want on each line</li>
	<li>select the font and font size to be used in the browser</li>
	<li>You can enter any text you want to search for in the <b>Seek
	Regular Expression</b> widget.
	<br>
	This text can be a simple text snippet such as "CQ" or any
	regular expression.  With a regex you can specify a more generic pattern,
	which means that you can match more things and your search is somewhat noise
	tolerant. Here is an example for a CQ from a US station (should match most
	callsigns):
	<br>
	<br>
	cq.+[aknw][a-z]?[0-9][a-pr-z][a-z]{1,2}
	<br>
	<br>
	This says "cq followed by at least one character, followed by one A,
	K, N, or W, followed by an optional letter, followed by a digit,
	followed by a letter that is not q, followed by one or two letters".
	The search is case-insensitive.
	<br>
	All plain text is a valid regular expression, unless you really had been
	looking for these metacharacters:
	<br>
	<br>
	.[{()\*+?|^$
	<br>
	<br>
	These will have to be escaped with a backslash.<br></li>
</ol>

<br>
<br>
\ref signal_browser_page "Return to Top of Page"
<br>
\ref main_page "Return to Main Page"

*/