QueryFocusStack Class Reference

#include "steam/mobject/session/query-focus-stack.hpp"

Description

A custom stack holding ScopePath »frames«.

It is utilised by the ScopeLocator to establish the current query focus location. Client code should access this mechanism through QueryFocus instances used as frontend. These QueryFocus objects incorporate a boost::intrusive_ptr, which stores the ref-count within the mentioned ScopePath frames located in the stack.

automatic cleanup of unused frames

The stack is aware of this ref-counting mechanism and will – on each access – automatically clean up any unused frames starting from stack top, until encountering the first frame still in use. This frame, by definition, is the current focus location. The stack ensures there is always at least one ScopePath frame, default-creating a new one if necessary.

See also

query-focus-stack-test.cpp

ScopeLocator

QueryFocus access point for client code

Definition at line 60 of file query-focus-stack.hpp.

Public Member Functions
	QueryFocusStack ()
bool	empty () const
size_t	size () const
ScopePath &	push (Scope const &)
	Open a new path frame, pushing down the current frame.
ScopePath &	top ()
void	pop_unused ()
	investigate the stack top and discard any path frames which aren't referred anymore (as indicated by their ScopePath::use_count().
void	clear ()

Private Member Functions
void	openDefaultFrame ()
Private Member Functions inherited from NonCopyable
	~NonCopyable ()=default
	NonCopyable ()=default
	NonCopyable (NonCopyable const &)=delete
NonCopyable &	operator= (NonCopyable const &)=delete

Private Attributes
std::list< ScopePath >	paths_

Constructor & Destructor Documentation

QueryFocusStack()

QueryFocusStack ( )

inline

Definition at line 67 of file query-focus-stack.hpp.

References QueryFocusStack::openDefaultFrame().

Here is the call graph for this function:

Member Function Documentation

empty()

bool empty

(

)

const

Definition at line 96 of file query-focus-stack.hpp.

References QueryFocusStack::paths_.

Referenced by QueryFocusStack::pop_unused(), and QueryFocusStack::top().

Here is the caller graph for this function:

size()

size_t size

(

)

const

Definition at line 103 of file query-focus-stack.hpp.

References QueryFocusStack::paths_.

Referenced by QueryFocusStack_test::automaticFrameHandling(), QueryFocusStack_test::clear(), QueryFocusStack::openDefaultFrame(), QueryFocusStack::pop_unused(), QueryFocusStack::push(), QueryFocusStack::top(), QueryFocusStack_test::usePushedFrame(), and QueryFocusStack_test::verify_errorHandling().

Here is the caller graph for this function:

push()

ScopePath & push

(

Scope const &

newStartPoint

)

Open a new path frame, pushing down the current frame.

The new frame tries to locate the given start scope and navigates to this position.

Note

EXCEPTION_STRONG guarantee

Returns

reference to the newly created path on top

Exceptions

error::Invalid

if newStartPoint isn't locatable

Definition at line 125 of file query-focus-stack.hpp.

References Scope::isRoot(), ScopePath::isValid(), QueryFocusStack::paths_, and QueryFocusStack::size().

Referenced by QueryFocusStack_test::automaticFrameHandling(), QueryFocusStack_test::clear(), QueryFocusStack_test::usePushedFrame(), and QueryFocusStack_test::verify_errorHandling().

Here is the call graph for this function:

Here is the caller graph for this function:

top()

ScopePath & top

(

)

Returns

the topmost path frame actually in use

Note

may invoke pop_unused()

EXCEPTON_FREE ///////TODO prove!

Definition at line 141 of file query-focus-stack.hpp.

References QueryFocusStack::empty(), QueryFocusStack::paths_, QueryFocusStack::pop_unused(), and QueryFocusStack::size().

Referenced by QueryFocusStack_test::automaticFrameHandling(), QueryFocusStack_test::clear(), QueryFocusStack_test::createStack(), QueryFocusStack_test::usePushedFrame(), and QueryFocusStack_test::verify_errorHandling().

Here is the call graph for this function:

Here is the caller graph for this function:

pop_unused()

void pop_unused

(

)

investigate the stack top and discard any path frames which aren't referred anymore (as indicated by their ScopePath::use_count().

After executing this function the topmost frame is either in use, or a new default frame has been created at the bottom of an empty stack.

Note

EXCEPTION_FREE ///////TODO prove!

Definition at line 161 of file query-focus-stack.hpp.

References QueryFocusStack::empty(), QueryFocusStack::openDefaultFrame(), QueryFocusStack::paths_, and QueryFocusStack::size().

Referenced by QueryFocusStack_test::automaticFrameHandling(), QueryFocusStack_test::clear(), QueryFocusStack::top(), and QueryFocusStack_test::usePushedFrame().

Here is the call graph for this function:

Here is the caller graph for this function:

clear()

void clear

(

)

Definition at line 110 of file query-focus-stack.hpp.

References QueryFocusStack::openDefaultFrame(), and QueryFocusStack::paths_.

Referenced by QueryFocusStack_test::clear().

Here is the call graph for this function:

Here is the caller graph for this function:

openDefaultFrame()

void openDefaultFrame ( )

private

open a default path frame at the bottom of an empty stack, locating to current model root

Note

EXCEPTION_FREE ///////TODO prove!

Definition at line 180 of file query-focus-stack.hpp.

References QueryFocusStack::paths_, and QueryFocusStack::size().

Referenced by QueryFocusStack::QueryFocusStack(), QueryFocusStack::clear(), and QueryFocusStack::pop_unused().

Here is the call graph for this function:

Here is the caller graph for this function:

Member Data Documentation

paths_

std::list<ScopePath> paths_

private

Definition at line 64 of file query-focus-stack.hpp.

Referenced by QueryFocusStack::clear(), QueryFocusStack::empty(), QueryFocusStack::openDefaultFrame(), QueryFocusStack::pop_unused(), QueryFocusStack::push(), QueryFocusStack::size(), and QueryFocusStack::top().

Inheritance diagram for QueryFocusStack:

Collaboration diagram for QueryFocusStack:

---

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

• query-focus-stack.hpp