KAccelGen Namespace Reference

Provides functions that, given a collection of QStrings, will automatically and intelligently assign menu accelerators to the QStrings in the collection. More...

Classes
class	Deref
	Static dereference class, for use as a template parameter. More...
class	Deref_Key
	Static dereference class that calls the key() method on its target; for use as a template parameter. More...
Functions
void	generate (const QStringList &source, QStringList &target)
template<class Iter , class Iter_Deref >
void	generate (Iter begin, Iter end, QStringList &target)
template<class Data >
void	generateFromKeys (const QMap< QString, Data > &source, QStringList &target)
template<class Iter >
void	generateFromKeys (Iter begin, Iter end, QStringList &target)
template<class Key >
void	generateFromValues (const QMap< Key, QString > &source, QStringList &target)
bool	isLegalAccelerator (const QString &str, uint index)
template<class Iter , class Deref >
void	loadPredefined (Iter begin, Iter end, QMap< QChar, bool > &keys)

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Detailed Description

Provides functions that, given a collection of QStrings, will automatically and intelligently assign menu accelerators to the QStrings in the collection.

NOTE: When this file speaks of "accelerators", we really mean accelerators as defined by the KDE User Interface Guidelines. We do NOT mean "shortcuts", which are what's handled by most other KDE libraries with "accel" in the name.

In the Qt library, the mechanism for adding a keyboard accelerator to a menu item is to insert an '&' before the letter. Since we usually don't want to disturb the original collection, the idiom in these functions is to populate a "target" QStringList parameter with the input collectin's QStrings, plus possibly some added '&' characters.

That is the mechanism. Here is the policy, in order of decreasing importance (it may seem like these are implementation details, but IMHO the policy is an important part of the interface):

1. If the string already contains an '&' character, skip this string, because we consider such strings to be "user-specified" accelerators.

2. No accelerator may clash with a previously defined accelerator, including any legal (alphanumeric) user-specified accelerator anywhere in the collection

3. Prefer alphanumerics at the start of the string.

4. Otherwise, prefer alphanumerics at the start of a word.

5. Otherwise, choose any alphanumeric character not already taken. If no such character is available, give up & skip this string.

A typical use of these functions would be to automatically assign accelerators to a dynamically populated popup menu. For example, the core code was written to automatically set accelerators for the "Load View Profile" popup menu for Konqueror. We quickly realized that it would be useful to make this facility more generally available, so I abstracted it out into a set of templates.

TODO:

+ Add sugar functions for more collections.

+ Add more Deref classes so that we can access a wider variety of collections.

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Function Documentation

void KAccelGen::generate	(	const QStringList &	source,
		QStringList &	target
	)			[inline]

Convenience function; generates accelerators for all the items in a QStringList.

Parameters:

	source	Strings for which to generate accelerators
	target	Output for accelerator-added strings

Definition at line 245 of file kaccelgen.h.

template<class Iter , class Iter_Deref >

void KAccelGen::generate	(	Iter	begin,
		Iter	end,
		QStringList &	target
	)			[inline]

Main, maximally flexible template function that assigns accelerators to the elements of a collection of QStrings.

Clients will seldom use this directly, as it's usually easier to use one of the wrapper functions that simply takes a collection (see below).

The Deref template parameter is a class containing a static dereferencing function, modeled after the comparison class C in Stroustrup 13.4.

Parameters:

	begin	(you know)
	end	(you know)
	target	collection to store generated strings

Definition at line 167 of file kaccelgen.h.

template<class Data >

void KAccelGen::generateFromKeys	(	const QMap< QString, Data > &	source,
		QStringList &	target
	)			[inline]

Convenience function; generates an accelerator mapping from all the keys in a QMap<QString,T>.

Parameters:

	source	Map with input strings as KEYS.
	target	Output for accelerator-added strings

Definition at line 271 of file kaccelgen.h.

template<class Iter >

void KAccelGen::generateFromKeys	(	Iter	begin,
		Iter	end,
		QStringList &	target
	)			[inline]

Another convenience function; looks up the key instead of dereferencing directly for the given iterator.

Parameters:

	begin
	end
	target

Definition at line 232 of file kaccelgen.h.

template<class Key >

void KAccelGen::generateFromValues	(	const QMap< Key, QString > &	source,
		QStringList &	target
	)			[inline]

Convenience function; generates accelerators for all the values in a QMap<T,QString>.

Parameters:

	source	Map with input strings as VALUES.
	target	Output for accelerator-added strings

Definition at line 258 of file kaccelgen.h.

bool KAccelGen::isLegalAccelerator	(	const QString &	str,
		uint	index
	)			[inline]

Helper to determine if the given offset in the string could be a legal alphanumeric accelerator.

Parameters:

	str	base string
	index	offset to check

Definition at line 114 of file kaccelgen.h.

template<class Iter , class Deref >

void KAccelGen::loadPredefined	(	Iter	begin,
		Iter	end,
		QMap< QChar, bool > &	keys
	)			[inline]

Loads all legal predefined accelerators in the (implicitly specified) collection into the given QMap.

Parameters:

	begin	start iterator
	end	(last+1) iterator
	keys	map to store output

Definition at line 130 of file kaccelgen.h.