kdeui Library API Documentation

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  KAccelGen::Deref< Iter >
 Static dereference class, for use as a template parameter. More...
class  KAccelGen::Deref_Key< Iter >
 Static dereference class that calls the key() method on its target; for use as a template parameter. More...

Functions

bool isLegalAccelerator (const QString &str, uint index)
template<class Iter, class Deref>
void loadPredefined (Iter begin, Iter end, QMap< QChar, bool > &keys)
template<class Iter, class Iter_Deref>
void generate (Iter begin, Iter end, QStringList &target)
template<class Iter>
void generateFromKeys (Iter begin, Iter end, QStringList &target)
void generate (const QStringList &source, QStringList &target)
template<class Key>
void generateFromValues (const QMap< Key, QString > &source, QStringList &target)
template<class Data>
void generateFromKeys (const QMap< QString, Data > &source, QStringList &target)


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.


Function Documentation

bool 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.

References isLegalAccelerator().

Referenced by generate(), isLegalAccelerator(), and loadPredefined().

template<class Iter, class Deref>
void 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.

References isLegalAccelerator(), and loadPredefined().

Referenced by loadPredefined().

template<class Iter, class Iter_Deref>
void generate Iter  begin,
Iter  end,
QStringList target
 

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.

References generate(), and isLegalAccelerator().

Referenced by generate().

template<class Iter>
void 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.

References generateFromKeys().

Referenced by generateFromKeys().

void 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.

References generate().

template<class Key>
void 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.

References generateFromValues().

Referenced by generateFromValues().

template<class Data>
void 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.

References generateFromKeys().

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