Gv::Ribbon Class Reference

Holds ribbon data that can be used to add a ribbon widget to a video stream display. More...

#include <gvribbon.h>

Classes
struct	Item
	A time bucket within a Gv::Ribbon. More...

Public Types
typedef std::vector< Item >	List

Public Member Functions
	Ribbon ()
	Default constructor for a zero-size() ribbon.
	Ribbon (size_t size, const G::Path &base, const std::string &name, const Gv::Timezone &tz)
	Constructor. More...
void	scan (const G::Path &path, size_t tpos)
	Does a complete scan for the day that encompases the given timestamped() file. More...
void	scan (const RibbonRange &range)
	Does a complete scan for the given day range.
bool	scanStart (G::FileTree &, const RibbonRange &range)
	Prepares for an iterative scan, with subsequent calls to scanSome(). More...
bool	scanStart (G::FileTree &, const G::Path &path, size_t tpos)
	Prepares for an iterative scan, with subsequent calls to scanSome(). More...
bool	scanSome (G::FileTree &, G::EpochTime interval)
	Does a partial scan, limited by the given time interval. More...
G::Path	find (size_t offset, bool before=false) const
	Finds the first scanned path at-or-after the given bucket position, or returns the last() path if there are no paths at-or-after the given position. More...
G::Path	last () const
	Returns the last scanned path. More...
G::Path	first () const
	Returns the first scanned path. More...
bool	apply (const G::Path &)
	Called when a possibly-new timestamped file is encountered, allowing the ribbon to update itself for that file. More...
size_t	size () const
	Returns the size of the list, as passed in to the constructor.
size_t	timepos (const G::Path &path) const
	Returns the timestamp position within the given path, or zero if none.
bool	timestamped (const G::Path &path) const
	Returns true if the given absolute path has a non-zero timepos().
List::const_iterator	begin () const
	Returns the item list's begin iterator.
List::const_iterator	end () const
	Returns the item list's end iterator.
const RibbonRange &	range () const
	Returns the current day range.
RibbonRange	range (int day_offset) const
	Returns a day range that is offset from the current day.
void	mark (const G::Path &)
	Marks the bucket that contains the given path. More...

Static Public Member Functions
static int	height ()
	Returns a suggested height of the ribbon, in pixels.
static size_t	timepos (const G::Path &path, const std::string &name)
	Returns the timestamp position within the given path, or zero if none.

Detailed Description

Holds ribbon data that can be used to add a ribbon widget to a video stream display.

The ribbon is populated by searching the filesystem for files with a suitable 'timestampy' path, ie. like '/base/yyyy/mm/dd/hh/mm/ss.ext' or '/base/yyyy/mm/dd/hh/mm/ss/xxx.ext'. If the timestamp is in the relevant range the file is allocated into one of a number of time buckets.

Definition at line 103 of file gvribbon.h.

Constructor & Destructor Documentation

Gv::Ribbon::Ribbon	(	size_t	size,
		const G::Path &	base,
		const std::string &	name,
		const Gv::Timezone &	tz
	)

Constructor.

The size parameter is the number of time buckets, which is typically the number of horizontal pixels. The base directory and timezone parameters are used in scan()ning. Use scan() to populate the ribbon.

Definition at line 39 of file gvribbon.cpp.

Member Function Documentation

bool Gv::Ribbon::apply

(

const G::Path &

path

)

Called when a possibly-new timestamped file is encountered, allowing the ribbon to update itself for that file.

Returns true if the apply()d file is outside the existing day range, implying that the ribbon needs to be rescanned.

Definition at line 154 of file gvribbon.cpp.

G::Path Gv::Ribbon::find	(	size_t	offset,
		bool	before = false
	)		const

Finds the first scanned path at-or-after the given bucket position, or returns the last() path if there are no paths at-or-after the given position.

Alternatively, finds the first scanned path at-or-before the given position, or returns the first() path if there are no paths at-or-before the given position. Precondition: offset < size()

Definition at line 215 of file gvribbon.cpp.

G::Path Gv::Ribbon::first

(

)

const

Returns the first scanned path.

Returns the empty path if all the buckets are empty.

Definition at line 198 of file gvribbon.cpp.

G::Path Gv::Ribbon::last

(

)

const

Returns the last scanned path.

Returns the empty path if all the buckets are empty.

Definition at line 206 of file gvribbon.cpp.

void Gv::Ribbon::mark

(

const G::Path &

)

Marks the bucket that contains the given path.

Marks on other buckets are cleared. See Gv::Ribbon::Item::marked().

void Gv::Ribbon::scan	(	const G::Path &	path,
		size_t	tpos
	)

Does a complete scan for the day that encompases the given timestamped() file.

Precondition: timestamped(path)

Definition at line 92 of file gvribbon.cpp.

bool Gv::Ribbon::scanSome	(	G::FileTree &	file_tree,
		G::EpochTime	interval
	)

Does a partial scan, limited by the given time interval.

Returns true if the scan is complete.

Definition at line 131 of file gvribbon.cpp.

bool Gv::Ribbon::scanStart	(	G::FileTree &	file_tree,
		const RibbonRange &	range
	)

Prepares for an iterative scan, with subsequent calls to scanSome().

The default-constructed G::FileTree object contains the scan state. Returns true if there is scanSome() work to do.

Definition at line 114 of file gvribbon.cpp.

bool Gv::Ribbon::scanStart	(	G::FileTree &	file_tree,
		const G::Path &	path,
		size_t	tpos
	)

Prepares for an iterative scan, with subsequent calls to scanSome().

The default-constructed G::FileTree object contains the scan state. Returns true if there is scanSome() work to do. Precondition: timestamped(path)

Definition at line 108 of file gvribbon.cpp.

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The documentation for this class was generated from the following files:

• /home/graeme/videotools/src/gvideo/gvribbon.h
• /home/graeme/videotools/src/gvideo/gvribbon.cpp