_LayerRef< TYPE > Struct Template Reference

Internal structure to keep weak pointer to QgsMapLayer or layerId if the layer is not available yet. More...

#include <qgsmaplayerref.h>

Public Member Functions
	_LayerRef (TYPE *l=nullptr)
	Constructor for a layer reference from an existing map layer. More...
	_LayerRef (const QString &id, const QString &name=QString(), const QString &source=QString(), const QString &provider=QString())
	Constructor for a weak layer reference, using a combination of layer ID, name, public source and provider key. More...
TYPE *	get () const
	Returns a pointer to the layer, or nullptr if the reference has not yet been matched to a layer. More...
bool	layerMatchesSource (QgsMapLayer *layer) const
	Returns true if a layer matches the weak references to layer public source, layer name and data provider contained in this layer reference. More...
	operator bool () const
	Returns true if the layer reference is resolved and contains a reference to an existing map layer. More...
TYPE *	operator-> () const
	Forwards the to map layer. More...
TYPE *	resolve ()
	Resolves the map layer by attempting to find a layer with matching ID within the map layer registry. More...
TYPE *	resolveWeakly ()
	Resolves the map layer by attempting to find a matching layer in the map layer registry using a weak match. More...
void	setLayer (TYPE *l)
	Sets the reference to point to a specified layer. More...

Public Attributes
QPointer< TYPE >	layer
	Weak pointer to map layer. More...
QString	layerId
	Original layer ID. More...
QString	name
	Weak reference to layer name. More...
QString	provider
	Weak reference to layer provider. More...
QString	source
	Weak reference to layer public source. More...

Detailed Description

template<typename TYPE>
struct _LayerRef< TYPE >

Internal structure to keep weak pointer to QgsMapLayer or layerId if the layer is not available yet.

Note

not available in Python bindings

Definition at line 34 of file qgsmaplayerref.h.

Constructor & Destructor Documentation

_LayerRef() [1/2]

template<typename TYPE>

_LayerRef< TYPE >::_LayerRef ( TYPE *  l = nullptr )

inline

Constructor for a layer reference from an existing map layer.

The layerId, source, name and provider members will automatically be populated from this layer.

Definition at line 42 of file qgsmaplayerref.h.

_LayerRef() [2/2]

template<typename TYPE>

_LayerRef< TYPE >::_LayerRef ( const QString &  id, const QString &  name = QString(), const QString &  source = QString(), const QString &  provider = QString()  )

inline

Constructor for a weak layer reference, using a combination of layer ID, name, public source and provider key.

Definition at line 54 of file qgsmaplayerref.h.

Member Function Documentation

get()

template<typename TYPE>

TYPE* _LayerRef< TYPE >::get ( ) const

inline

Returns a pointer to the layer, or nullptr if the reference has not yet been matched to a layer.

Definition at line 95 of file qgsmaplayerref.h.

layerMatchesSource()

template<typename TYPE>

bool _LayerRef< TYPE >::layerMatchesSource ( QgsMapLayer *  layer ) const

inline

Returns true if a layer matches the weak references to layer public source, layer name and data provider contained in this layer reference.

See also

resolveWeakly()

Definition at line 118 of file qgsmaplayerref.h.

operator bool()

template<typename TYPE>

_LayerRef< TYPE >::operator bool ( ) const

inline

Returns true if the layer reference is resolved and contains a reference to an existing map layer.

Definition at line 78 of file qgsmaplayerref.h.

operator->()

template<typename TYPE>

TYPE* _LayerRef< TYPE >::operator-> ( ) const

inline

Forwards the to map layer.

Definition at line 86 of file qgsmaplayerref.h.

resolve()

template<typename TYPE>

TYPE* _LayerRef< TYPE >::resolve ( )

inline

Resolves the map layer by attempting to find a layer with matching ID within the map layer registry.

If found, this reference will be updated to match the found layer and the layer will be returned. If no matching layer is found, a nullptr is returned.

See also

resolveWeakly()

Definition at line 137 of file qgsmaplayerref.h.

resolveWeakly()

template<typename TYPE>

TYPE* _LayerRef< TYPE >::resolveWeakly ( )

inline

Resolves the map layer by attempting to find a matching layer in the map layer registry using a weak match.

First, the layer is attempted to match to registry layers using the layer's ID (calling this method implicitly calls resolve()).

Failing a match by layer ID, the layer will be matched by using the weak references to layer public source, layer name and data provider contained in this layer reference.

If a matching layer is found, this reference will be updated to match the found layer and the layer will be returned. If no matching layer is found, a nullptr is returned.

See also

resolve()

layerMatchesSource()

Definition at line 167 of file qgsmaplayerref.h.

setLayer()

template<typename TYPE>

void _LayerRef< TYPE >::setLayer ( TYPE *  l )

inline

Sets the reference to point to a specified layer.

Definition at line 65 of file qgsmaplayerref.h.

Member Data Documentation

layer

template<typename TYPE>

QPointer<TYPE> _LayerRef< TYPE >::layer

Weak pointer to map layer.

Definition at line 101 of file qgsmaplayerref.h.

layerId

template<typename TYPE>

QString _LayerRef< TYPE >::layerId

Original layer ID.

Definition at line 104 of file qgsmaplayerref.h.

name

template<typename TYPE>

QString _LayerRef< TYPE >::name

Weak reference to layer name.

Definition at line 109 of file qgsmaplayerref.h.

provider

template<typename TYPE>

QString _LayerRef< TYPE >::provider

Weak reference to layer provider.

Definition at line 111 of file qgsmaplayerref.h.

source

template<typename TYPE>

QString _LayerRef< TYPE >::source

Weak reference to layer public source.

Definition at line 107 of file qgsmaplayerref.h.

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

• /tmp/buildd/qgis-2.18.21+99unstable/src/core/qgsmaplayerref.h