Quantum GIS API Documentation  1.7.5-Wroclaw
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QgsProject Class Reference

Reads and writes project states. More...

#include <qgsproject.h>

Inheritance diagram for QgsProject:
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Classes

struct  Imp
 

Signals

void readProject (const QDomDocument &)
 emitted when project is being read More...
 
void writeProject (QDomDocument &)
 emitted when project is being written More...
 
void oldProjectVersionWarning (QString)
 emitted when an old project file is read. More...
 
void layerLoaded (int i, int n)
 emitted when a layer from a projects was read More...
 

Public Member Functions

 ~QgsProject ()
 
bool read (QDomNode &layerNode)
 read the layer described in the associated Dom node More...
 
void clearProperties ()
 syntactic sugar for property lists More...
 
bool removeEntry (QString const &scope, const QString &key)
 remove the given key More...
 
QStringList entryList (QString const &scope, QString const &key) const
 return keys with values – do not return keys that contain other keys More...
 
QStringList subkeyList (QString const &scope, QString const &key) const
 return keys with keys – do not return keys that contain only values More...
 
void dumpProperties () const
 dump out current project properties to stderr More...
 
QString writePath (QString filename) const
 prepare a filename to save it to the project file More...
 
QString readPath (QString filename) const
 turn filename read from the project file to an absolute path More...
 
QString error () const
 Return error message from previous read/write. More...
 
void setBadLayerHandler (QgsProjectBadLayerHandler *handler)
 Change handler for missing layers. More...
 
void title (QString const &title)
 Every project has an associated title string. More...
 
QString const & title () const
 returns title More...
 
bool isDirty () const
 the dirty flag is true if the project has been modified since the last write() More...
 
void dirty (bool b)
 
void setFileName (QString const &name)
 Every project has an associated file that contains its XML. More...
 
QString fileName () const
 returns file name More...
 
bool read (QFileInfo const &file)
 read project file More...
 
bool read ()
 presuming that the caller has already reset the map canvas, map registry, and legend More...
 
bool write (QFileInfo const &file)
 write project file More...
 
bool write ()
 
bool writeEntry (QString const &scope, const QString &key, bool value)
 
bool writeEntry (QString const &scope, const QString &key, double value)
 
bool writeEntry (QString const &scope, const QString &key, int value)
 
bool writeEntry (QString const &scope, const QString &key, const QString &value)
 
bool writeEntry (QString const &scope, const QString &key, const QStringList &value)
 
QStringList readListEntry (QString const &scope, const QString &key, bool *ok=0) const
 key value accessors More...
 
QString readEntry (QString const &scope, const QString &key, const QString &def=QString::null, bool *ok=0) const
 
int readNumEntry (QString const &scope, const QString &key, int def=0, bool *ok=0) const
 
double readDoubleEntry (QString const &scope, const QString &key, double def=0, bool *ok=0) const
 
bool readBoolEntry (QString const &scope, const QString &key, bool def=false, bool *ok=0) const
 

Static Public Member Functions

static QgsProjectinstance ()
 access to canonical QgsProject instance More...
 

Protected Member Functions

void setError (QString errorMessage)
 Set error message from read/write operation. More...
 
void clearError ()
 Clear error message. More...
 

Private Member Functions

 QgsProject ()
 
 QgsProject (QgsProject const &)
 
QPair< bool, QList< QDomNode > > _getMapLayers (QDomDocument const &doc)
 Read map layers from project file. More...
 

Private Attributes

std::auto_ptr< Impimp_
 implementation handle More...
 
QString mErrorMessage
 
QgsProjectBadLayerHandlermBadLayerHandler
 

Static Private Attributes

static QgsProjecttheProject_
 

Detailed Description

Reads and writes project states.

Note

Has two general kinds of state to make persistent. (I.e., to read and write.) First, Qgis proprietary information. Second plug-in information.

A singleton since there shall only be one active project at a time; and provides canonical location for plug-ins and main app to find/set properties.

Might want to consider moving from Singleton; i.e., allowing more than one project. Just as the GIMP can have simultaneous multiple images, perhaps qgis can one day have simultaneous multiple projects.

Definition at line 57 of file qgsproject.h.

Constructor & Destructor Documentation

QgsProject::~QgsProject ( )
Todo:
XXX Should have semantics for saving project if dirty as last gasp?

Definition at line 351 of file qgsproject.cpp.

References mBadLayerHandler.

QgsProject::QgsProject ( )
private

Definition at line 336 of file qgsproject.cpp.

References dirty(), and writeEntry().

Referenced by instance().

QgsProject::QgsProject ( QgsProject const &  )
private

Member Function Documentation

QPair< bool, QList< QDomNode > > QgsProject::_getMapLayers ( QDomDocument const &  doc)
private

Read map layers from project file.

Returns
QPair< bool, QList<QDomNode> >
bool is true if function worked; else is false. list contains nodes corresponding to layers that couldn't be loaded
Note
XML of form:
   <maplayer type="vector">
      <layername>Hydrop</layername>
      <datasource>/data/usgs/city_shp/hydrop.shp</datasource>
      <zorder>0</zorder>
      <provider>ogr</provider>
      <singlesymbol>
         <renderitem>
            <value>blabla</value>
            <symbol>
               <outlinecolor red="85" green="0" blue="255" />
               <outlinestyle>SolidLine</outlinestyle>
               <outlinewidth>1</outlinewidth>
               <fillcolor red="0" green="170" blue="255" />
               <fillpattern>SolidPattern</fillpattern>
            </symbol>
            <label>blabla</label>
         </renderitem>
      </singlesymbol>
      <label>0</label>
      <labelattributes>
         <label text="Label" field="" />
         <family name="Sans Serif" field="" />
         <size value="12" units="pt" field="" />
         <bold on="0" field="" />
         <italic on="0" field="" />
         <underline on="0" field="" />
         <color red="0" green="0" blue="0" field="" />
         <x field="" />
         <y field="" />
         <offset  units="pt" x="0" xfield="" y="0" yfield="" />
         <angle value="0" field="" />
         <alignment value="center" field="" />
      </labelattributes>
   </maplayer>

Definition at line 649 of file qgsproject.cpp.

References QgsMapLayerRegistry::addMapLayer(), QgsPluginLayerRegistry::createLayer(), QgsMapLayerRegistry::instance(), QgsPluginLayerRegistry::instance(), QgsMapLayer::isValid(), layerLoaded(), QgsDebugMsg, QgsMapLayer::readXML(), and QgsVectorLayer::vectorJoins().

Referenced by read().

void QgsProject::clearError ( )
protected

Clear error message.

Note
added in 1.4

Definition at line 1538 of file qgsproject.cpp.

References setError().

Referenced by read(), and write().

void QgsProject::clearProperties ( )

syntactic sugar for property lists

extra properties, typically added by plug-ins

This allows for extra properties to be associated with projects. Think of it as a registry bound to a project.

Properties are arbitrary values keyed by a name and associated with a scope. The scope would presumably refer to your plug-in. E.g., "openmodeller".

Note

E.g., open modeller might use:

"QgsProject::instance()->properties("openmodeller")["foo"].

Todo:
"properties" is, overall, a good name; but that might imply that the qgis specific state properites are different since they aren't accessible here. Actually, what if we make "qgis" yet another scope that stores its state in the properties list? E.g., QgsProject::instance()->properties()["qgis"]?

removes all project properties

Definition at line 1084 of file qgsproject.cpp.

References dirty(), and imp_.

void QgsProject::dirty ( bool  b)

Definition at line 393 of file qgsproject.cpp.

References imp_.

Referenced by clearProperties(), QgsProject(), read(), removeEntry(), setFileName(), title(), write(), and writeEntry().

void QgsProject::dumpProperties ( ) const

dump out current project properties to stderr

Todo:
XXX Now slightly broken since re-factoring. Won't print out top-level key and redundantly prints sub-keys.

Definition at line 1344 of file qgsproject.cpp.

References dump_(), and imp_.

QStringList QgsProject::entryList ( QString const &  scope,
QString const &  key 
) const

return keys with values – do not return keys that contain other keys

Note
equivalent to QSettings entryList()

Definition at line 1305 of file qgsproject.cpp.

References QgsPropertyKey::entryList(), findKey_(), and imp_.

QString QgsProject::error ( ) const

Return error message from previous read/write.

Note
added in 1.4

Definition at line 1533 of file qgsproject.cpp.

References mErrorMessage.

QString QgsProject::fileName ( ) const

returns file name

Definition at line 409 of file qgsproject.cpp.

References imp_.

Referenced by readPath(), and writePath().

QgsProject * QgsProject::instance ( )
static
bool QgsProject::isDirty ( ) const

the dirty flag is true if the project has been modified since the last write()

Definition at line 387 of file qgsproject.cpp.

References imp_.

void QgsProject::layerLoaded ( int  i,
int  n 
)
signal

emitted when a layer from a projects was read

Referenced by _getMapLayers().

void QgsProject::oldProjectVersionWarning ( QString  )
signal

emitted when an old project file is read.

Referenced by read().

bool QgsProject::read ( QFileInfo const &  file)

read project file

Please note that most of the contents were copied from qgsproject.

Note
Any current plug-in state is erased
dirty set to false after successful invocation
file name argument implicitly sets file

(Is that really desirable behavior? Maybe prompt to save before reading new one?)

Should we presume the file is opened elsewhere? Or do we open it ourselves?

XXX How to best get modify access to Qgis state? Actually we can finagle that by searching for qgisapp in object hiearchy.

Note
  • Gets the extents
  • Creates maplayers
  • Registers maplayers
it's presumed that the caller has already reset the map canvas, map registry, and legend

Definition at line 767 of file qgsproject.cpp.

References imp_, and read().

Referenced by QgsProjectBadLayerGuiHandler::findMissingFile().

bool QgsProject::read ( )

presuming that the caller has already reset the map canvas, map registry, and legend

Shows a warning when an old project file is read.

Definition at line 779 of file qgsproject.cpp.

References _getMapLayers(), _getProperties(), _getTitle(), _getVersion(), clearError(), dirty(), dump_(), QgsProjectBadLayerHandler::handleBadLayers(), imp_, mBadLayerHandler, oldProjectVersionWarning(), QGis::QGIS_VERSION, QgsDebugMsg, readProject(), setError(), QgsProjectVersion::text(), and QgsLogger::warning().

Referenced by read().

bool QgsProject::read ( QDomNode &  layerNode)

read the layer described in the associated Dom node

Parameters
layerNoderepresents a QgsProject Dom node that maps to a specific layer.

QgsProject raises an exception when one of the QgsProject::read() implementations fails. Since the read()s are invoked from qgisapp, then qgisapp handles the exception. It prompts the user for the new location of the data, if any. If there is a new location, the Dom node associated with the layer has its datasource tag corrected. Then that node is passed to this member function to be re-opened.

Definition at line 905 of file qgsproject.cpp.

References QgsMapLayerRegistry::addMapLayer(), QgsPluginLayerRegistry::createLayer(), QgsMapLayerRegistry::instance(), QgsPluginLayerRegistry::instance(), QgsDebugMsg, and QgsMapLayer::readXML().

bool QgsProject::readBoolEntry ( QString const &  scope,
const QString &  key,
bool  def = false,
bool *  ok = 0 
) const

Definition at line 1266 of file qgsproject.cpp.

References findKey_(), and imp_.

Referenced by readPath(), and writePath().

double QgsProject::readDoubleEntry ( QString const &  scope,
const QString &  key,
double  def = 0,
bool *  ok = 0 
) const

Definition at line 1236 of file qgsproject.cpp.

References findKey_(), and imp_.

QString QgsProject::readEntry ( QString const &  scope,
const QString &  key,
const QString &  def = QString::null,
bool *  ok = 0 
) const

Definition at line 1176 of file qgsproject.cpp.

References findKey_(), and imp_.

QStringList QgsProject::readListEntry ( QString const &  scope,
const QString &  key,
bool *  ok = 0 
) const

key value accessors

keys would be the familiar QSettings-like '/' delimited entries, implying a hierarchy of keys and corresponding values

Note
The key string must include '/'s. E.g., "/foo" not "foo".

Definition at line 1146 of file qgsproject.cpp.

References findKey_(), and imp_.

Referenced by QgsGeometry::avoidIntersections(), and QgsMapCanvasSnapper::snapToBackgroundLayers().

int QgsProject::readNumEntry ( QString const &  scope,
const QString &  key,
int  def = 0,
bool *  ok = 0 
) const
QString QgsProject::readPath ( QString  filename) const

turn filename read from the project file to an absolute path

Note
added in 1.3

Definition at line 1351 of file qgsproject.cpp.

References fileName(), and readBoolEntry().

Referenced by QgsVectorLayer::readSymbology(), QgsComposerPicture::readXML(), and QgsMapLayer::readXML().

void QgsProject::readProject ( const QDomDocument &  )
signal

emitted when project is being read

Referenced by read().

bool QgsProject::removeEntry ( QString const &  scope,
const QString &  key 
)

remove the given key

Definition at line 1294 of file qgsproject.cpp.

References dirty(), findKey_(), imp_, and removeKey_().

void QgsProject::setBadLayerHandler ( QgsProjectBadLayerHandler handler)

Change handler for missing layers.

Deletes old handler and takes ownership of the new one.

Note
added in 1.4

Definition at line 1543 of file qgsproject.cpp.

References mBadLayerHandler.

void QgsProject::setError ( QString  errorMessage)
protected

Set error message from read/write operation.

Note
added in 1.4

Definition at line 1528 of file qgsproject.cpp.

References mErrorMessage.

Referenced by clearError(), read(), and write().

void QgsProject::setFileName ( QString const &  name)

Every project has an associated file that contains its XML.

Definition at line 400 of file qgsproject.cpp.

References dirty(), and imp_.

QStringList QgsProject::subkeyList ( QString const &  scope,
QString const &  key 
) const

return keys with keys – do not return keys that contain only values

Note
equivalent to QSettings subkeyList()

Definition at line 1324 of file qgsproject.cpp.

References findKey_(), imp_, and QgsPropertyKey::subkeyList().

void QgsProject::title ( QString const &  title)

Every project has an associated title string.

Todo:
However current dialogs don't allow setting of it yet

Definition at line 373 of file qgsproject.cpp.

References dirty(), imp_, and title().

QString const & QgsProject::title ( ) const

returns title

Definition at line 381 of file qgsproject.cpp.

References imp_.

Referenced by title(), and write().

bool QgsProject::write ( QFileInfo const &  file)

write project file

XXX How to best get read access to Qgis state? Actually we can finagle that by searching for qgisapp in object hiearchy.

Note
file name argument implicitly sets file
dirty set to false after successful invocation

Definition at line 955 of file qgsproject.cpp.

References imp_, and write().

bool QgsProject::write ( )
bool QgsProject::writeEntry ( QString const &  scope,
const QString &  key,
bool  value 
)

Definition at line 1096 of file qgsproject.cpp.

References addKey_(), dirty(), and imp_.

Referenced by QgsProject::Imp::clear(), and QgsProject().

bool QgsProject::writeEntry ( QString const &  scope,
const QString &  key,
double  value 
)

Definition at line 1105 of file qgsproject.cpp.

References addKey_(), dirty(), and imp_.

bool QgsProject::writeEntry ( QString const &  scope,
const QString &  key,
int  value 
)

Definition at line 1115 of file qgsproject.cpp.

References addKey_(), dirty(), and imp_.

bool QgsProject::writeEntry ( QString const &  scope,
const QString &  key,
const QString &  value 
)

Definition at line 1124 of file qgsproject.cpp.

References addKey_(), dirty(), and imp_.

bool QgsProject::writeEntry ( QString const &  scope,
const QString &  key,
const QStringList &  value 
)

Definition at line 1134 of file qgsproject.cpp.

References addKey_(), dirty(), and imp_.

QString QgsProject::writePath ( QString  filename) const

prepare a filename to save it to the project file

Note
added in 1.3

Definition at line 1448 of file qgsproject.cpp.

References fileName(), and readBoolEntry().

Referenced by QgsMapLayer::writeXML().

void QgsProject::writeProject ( QDomDocument &  )
signal

emitted when project is being written

Referenced by write().

Member Data Documentation

std::auto_ptr<Imp> QgsProject::imp_
private
QgsProjectBadLayerHandler* QgsProject::mBadLayerHandler
private

Definition at line 319 of file qgsproject.h.

Referenced by read(), setBadLayerHandler(), and ~QgsProject().

QString QgsProject::mErrorMessage
private

Definition at line 317 of file qgsproject.h.

Referenced by error(), and setError().

QgsProject * QgsProject::theProject_
staticprivate

Definition at line 313 of file qgsproject.h.

Referenced by instance().


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