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	loadAllValues ()
void	loadSampleValues ()
void	on_expressionTree_doubleClicked (const QModelIndex &index)
void	on_lblPreview_linkActivated (QString link)
void	on_mValueListWidget_itemDoubleClicked (QListWidgetItem *item)
void	on_txtExpressionString_textChanged ()
void	on_txtSearchEdit_textChanged ()
void	operatorButtonClicked ()
void	showContextMenu (const QPoint &)
Signals
void	expressionParsed (bool isValid)
	Emitted when the user changes the expression in the widget.
Public Member Functions
	QgsExpressionBuilderWidget (QWidget *parent)
	~QgsExpressionBuilderWidget ()
QString	expressionText ()
	Gets the expression string that has been set in the expression area.
bool	isExpressionValid ()
void	loadFieldNames ()
	Loads all the field names from the layer.
void	loadFieldNames (const QgsFields &fields)
void	registerItem (QString group, QString label, QString expressionText, QString helpText="", QgsExpressionItem::ItemType type=QgsExpressionItem::ExpressionNode)
	Registers a node item for the expression builder.
void	setExpressionText (const QString &expression)
	Sets the expression string for the widget.
void	setGeomCalculator (const QgsDistanceArea &da)
	Sets geometry calculator used in distance/area calculations.
void	setLayer (QgsVectorLayer *layer)
	Sets layer in order to get the fields and values.
Private Slots
void	setExpressionState (bool state)
Private Member Functions
void	fillFieldValues (int fieldIndex, int countLimit)
QString	loadFunctionHelp (QgsExpressionItem *functionName)
Private Attributes
QgsExpressionHighlighter *	highlighter
QgsDistanceArea	mDa
QMap< QString, QgsExpressionItem * >	mExpressionGroups
bool	mExpressionValid
QgsFeature	mFeature
QgsVectorLayer *	mLayer
QStandardItemModel *	mModel
QgsExpressionItemSearchProxy *	mProxyModel

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 ( )

Definition at line 113 of file qgsexpressionbuilderwidget.cpp.

Member Function Documentation

void QgsExpressionBuilderWidget::currentChanged	(	const QModelIndex &	index,
		const QModelIndex &
	)		`[slot]`

Definition at line 123 of file qgsexpressionbuilderwidget.cpp.

References QgsExpressionItem::Field, QgsExpressionItem::getItemType(), loadFunctionHelp(), 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 250 of file qgsexpressionbuilderwidget.cpp.

void QgsExpressionBuilderWidget::fillFieldValues	(	int	fieldIndex,
		int	countLimit
	)		`[private]`

Definition at line 187 of file qgsexpressionbuilderwidget.cpp.

References mLayer, and QgsVectorLayer::uniqueValues().

Referenced by loadAllValues(), and loadSampleValues().

bool QgsExpressionBuilderWidget::isExpressionValid ( )

Definition at line 240 of file qgsexpressionbuilderwidget.cpp.

References mExpressionValid.

void QgsExpressionBuilderWidget::loadAllValues ( ) [slot]

Definition at line 395 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 161 of file qgsexpressionbuilderwidget.cpp.

References mLayer, and QgsVectorLayer::pendingFields().

void QgsExpressionBuilderWidget::loadFieldNames ( const QgsFields & fields )

Definition at line 171 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 414 of file qgsexpressionbuilderwidget.cpp.

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

Referenced by currentChanged().

void QgsExpressionBuilderWidget::loadSampleValues ( ) [slot]

Definition at line 381 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 146 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 344 of file qgsexpressionbuilderwidget.cpp.

References QgsMessageViewer::setMessageAsHtml(), and tr.

void QgsExpressionBuilderWidget::on_mValueListWidget_itemDoubleClicked ( QListWidgetItem * item ) [slot]

Definition at line 353 of file qgsexpressionbuilderwidget.cpp.

void QgsExpressionBuilderWidget::on_txtSearchEdit_textChanged ( ) [slot]

Definition at line 335 of file qgsexpressionbuilderwidget.cpp.

References mProxyModel.

void QgsExpressionBuilderWidget::operatorButtonClicked ( ) [slot]

Definition at line 358 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.