A reusable widget that can be used to build a expression string. More...

#include <qgsexpressionbuilderwidget.h>

Collaboration diagram for QgsExpressionBuilderWidget:

Public Slots
void	currentChanged (const QModelIndex &index, const QModelIndex &)
void	on_expressionTree_doubleClicked (const QModelIndex &index)
void	on_txtExpressionString_textChanged ()
void	on_txtSearchEdit_textChanged ()
void	on_lblPreview_linkActivated (QString link)
void	on_mValueListWidget_itemDoubleClicked (QListWidgetItem *item)
void	operatorButtonClicked ()
void	showContextMenu (const QPoint &)
void	loadSampleValues ()
void	loadAllValues ()

Signals
void	expressionParsed (bool isValid)
	Emitted when the user changes the expression in the widget.

Public Member Functions
	QgsExpressionBuilderWidget (QWidget *parent)
	~QgsExpressionBuilderWidget ()
void	setLayer (QgsVectorLayer *layer)
	Sets layer in order to get the fields and values.
void	loadFieldNames ()
	Loads all the field names from the layer.
void	loadFieldNames (const QgsFields &fields)
void	setGeomCalculator (const QgsDistanceArea &da)
	Sets geometry calculator used in distance/area calculations.
QString	expressionText ()
	Gets the expression string that has been set in the expression area.
void	setExpressionText (const QString &expression)
	Sets the expression string for the widget.
void	registerItem (QString group, QString label, QString expressionText, QString helpText="", QgsExpressionItem::ItemType type=QgsExpressionItem::ExpressionNode)
	Registers a node item for the expression builder.
bool	isExpressionValid ()
void	saveToRecent (QString key)
void	loadRecent (QString key)

Private Slots
void	setExpressionState (bool state)

Private Member Functions
void	fillFieldValues (int fieldIndex, int countLimit)
QString	loadFunctionHelp (QgsExpressionItem *functionName)

Private Attributes
QgsVectorLayer *	mLayer
QStandardItemModel *	mModel
QgsExpressionItemSearchProxy *	mProxyModel
QMap< QString, QgsExpressionItem * >	mExpressionGroups
QgsFeature	mFeature
QgsExpressionHighlighter *	highlighter
bool	mExpressionValid
QgsDistanceArea	mDa

Detailed Description

A reusable widget that can be used to build a expression string.

See QgsExpressionBuilderDialog for exmaple of usage.

Definition at line 107 of file qgsexpressionbuilderwidget.h.

Constructor & Destructor Documentation

QgsExpressionBuilderWidget::QgsExpressionBuilderWidget ( QWidget * parent )

QgsExpressionBuilderWidget::~QgsExpressionBuilderWidget ( )

Definition at line 110 of file qgsexpressionbuilderwidget.cpp.

Member Function Documentation

void QgsExpressionBuilderWidget::currentChanged	(	const QModelIndex &	index,
		const QModelIndex &
	)

slot

Definition at line 120 of file qgsexpressionbuilderwidget.cpp.

References QgsExpressionItem::Field, QgsExpressionItem::getItemType(), loadFunctionHelp(), mLayer, mModel, and mProxyModel.

Referenced by QgsExpressionBuilderWidget().

void QgsExpressionBuilderWidget::expressionParsed ( bool isValid )

signal

Emitted when the user changes the expression in the widget.

Users of this widget should connect to this signal to decide if to let the user continue.

Parameters

isValid Is true if the expression the user has typed is valid.

Referenced by on_txtExpressionString_textChanged(), and QgsExpressionBuilderWidget().

QString QgsExpressionBuilderWidget::expressionText ( )

Gets the expression string that has been set in the expression area.

Returns: The expression as a string.

Definition at line 283 of file qgsexpressionbuilderwidget.cpp.

Referenced by saveToRecent().

void QgsExpressionBuilderWidget::fillFieldValues	(	int	fieldIndex,
		int	countLimit
	)

private

Definition at line 184 of file qgsexpressionbuilderwidget.cpp.

References mLayer, and QgsVectorLayer::uniqueValues().

Referenced by loadAllValues(), and loadSampleValues().

bool QgsExpressionBuilderWidget::isExpressionValid ( )

Definition at line 237 of file qgsexpressionbuilderwidget.cpp.

References mExpressionValid.

void QgsExpressionBuilderWidget::loadAllValues ( )

slot

Definition at line 430 of file qgsexpressionbuilderwidget.cpp.

References QgsVectorLayer::fieldNameIndex(), fillFieldValues(), mLayer, mModel, and mProxyModel.

Referenced by QgsExpressionBuilderWidget(), and showContextMenu().

void QgsExpressionBuilderWidget::loadFieldNames ( )

Loads all the field names from the layer.

Remarks: Should this really be public couldn't we just do this for the user?

Definition at line 158 of file qgsexpressionbuilderwidget.cpp.

References mLayer, and QgsVectorLayer::pendingFields().

void QgsExpressionBuilderWidget::loadFieldNames ( const QgsFields & fields )

Definition at line 168 of file qgsexpressionbuilderwidget.cpp.

References QgsExpressionHighlighter::addFields(), QgsFields::count(), QgsExpressionItem::Field, highlighter, QgsFields::isEmpty(), and registerItem().

QString QgsExpressionBuilderWidget::loadFunctionHelp ( QgsExpressionItem * functionName )

private

Definition at line 449 of file qgsexpressionbuilderwidget.cpp.

References QgsExpressionItem::Field, QgsExpressionItem::getHelpText(), QgsExpressionItem::getItemType(), QgsExpression::helptext(), and QgsApplication::reportStyleSheet().

Referenced by currentChanged().

void QgsExpressionBuilderWidget::loadRecent ( QString key )

Definition at line 260 of file qgsexpressionbuilderwidget.cpp.

References mExpressionGroups, registerItem(), and tr.

Referenced by saveToRecent().

void QgsExpressionBuilderWidget::loadSampleValues ( )

slot

Definition at line 416 of file qgsexpressionbuilderwidget.cpp.

References QgsVectorLayer::fieldNameIndex(), fillFieldValues(), mLayer, mModel, and mProxyModel.

Referenced by QgsExpressionBuilderWidget(), and showContextMenu().

void QgsExpressionBuilderWidget::on_expressionTree_doubleClicked ( const QModelIndex & index )

slot

Definition at line 142 of file qgsexpressionbuilderwidget.cpp.

References QgsExpressionItem::getExpressionText(), QgsExpressionItem::getItemType(), QgsExpressionItem::Header, mModel, and mProxyModel.

void QgsExpressionBuilderWidget::on_lblPreview_linkActivated ( QString link )

slot

Definition at line 377 of file qgsexpressionbuilderwidget.cpp.

References QgsMessageViewer::setMessageAsHtml(), and tr.

void QgsExpressionBuilderWidget::on_mValueListWidget_itemDoubleClicked ( QListWidgetItem * item )

slot

Definition at line 386 of file qgsexpressionbuilderwidget.cpp.

void QgsExpressionBuilderWidget::on_txtExpressionString_textChanged ( )

slot

Definition at line 293 of file qgsexpressionbuilderwidget.cpp.

References QgsExpression::evalErrorString(), QgsExpression::evaluate(), expressionParsed(), QgsVectorLayer::getFeatures(), QgsExpression::hasEvalError(), QgsExpression::hasParserError(), QgsFeature::isValid(), mDa, mFeature, mLayer, QgsFeatureIterator::nextFeature(), QgsExpression::parserErrorString(), QgsVectorLayer::pendingFields(), QgsExpression::setGeomCalculator(), and tr.

void QgsExpressionBuilderWidget::on_txtSearchEdit_textChanged ( )

slot

Definition at line 368 of file qgsexpressionbuilderwidget.cpp.

References mProxyModel.

void QgsExpressionBuilderWidget::operatorButtonClicked ( )

slot

Definition at line 392 of file qgsexpressionbuilderwidget.cpp.

Referenced by QgsExpressionBuilderWidget().

void QgsExpressionBuilderWidget::registerItem	(	QString	group,
		QString	label,
		QString	expressionText,
		QString	helpText = `""`,
		QgsExpressionItem::ItemType	type = `QgsExpressionItem::ExpressionNode`
	)

Registers a node item for the expression builder.

Parameters

group	The group the item will be show in the tree view. If the group doesn't exsit it will be created.
label	The label that is show to the user for the item in the tree.
expressionText	The text that is inserted into the expression area when the user double clicks on the item.
helpText	The help text that the user will see when item is selected.
type	The type of the expression item.