Class: QgsFilterLineEdit

QLineEdit subclass with built in support for clearing the widget’s value and handling custom null value representations.

When using QgsFilterLineEdit the value(), setValue() and clearValue() methods should be used instead of QLineEdit’s text(), setText() and clear() methods, and the valueChanged() signal should be used instead of textChanged().

Class Hierarchy

Inheritance diagram of qgis.gui.QgsFilterLineEdit

Base classes

QLineEdit

QWidget

QObject

QPaintDevice

Subclasses

QgsFieldValuesLineEdit

A line edit with an autocompleter which takes unique values from a vector layer’s fields.

QgsHighlightableLineEdit

A QgsFilterLineEdit subclass with the ability to “highlight” the edges of the widget.

Methods

clearMode

Returns the clear mode for the widget.

defaultValue

Returns the default value for the widget.

hasStateStored

Returns if a state is already saved

isNull

Determine if the current text represents null.

nullValue

Returns the string used for representing null values in the widget.

restoreState

Restores the current state of the line edit (selection and cursor position)

selectOnFocus

Will select all text when this widget receives the focus.

setClearMode

Sets the clear mode for the widget.

setDefaultValue

Sets the default value for the widget.

setNullValue

Sets the string representation for null values in the widget.

setSelectOnFocus

Will select all text when this widget receives the focus.

setShowClearButton

Sets whether the widget's clear button is visible.

setShowSearchIcon

Define if a search icon shall be shown on the left of the image when no text is entered

setShowSpinner

Show a spinner icon.

setValue

Sets the current text for the widget with support for handling null values.

showClearButton

Returns True if the widget's clear button is visible.

showSearchIcon

Returns if a search icon shall be shown on the left of the image when no text is entered

showSpinner

Show a spinner icon.

storeState

Stores the current state of the line edit (selection and cursor position)

value

Returns the text of this edit with support for handling null values.

Virtual Methods

In PyQGIS, only methods marked as virtual can be safely overridden in a Python subclass of QgsFilterLineEdit. See the FAQ for more details.

clearValue

Clears the widget and resets it to the null value.

event

Reimplemented to enable/disable the clear action depending on read-only status

Signals

cleared

Emitted when the widget is cleared

selectOnFocusChanged

Will select all text when this widget receives the focus.

showSpinnerChanged

Show a spinner icon.

valueChanged

Same as textChanged() but with support for null values.

Attributes

ClearToDefault

ClearToNull

class qgis.gui.QgsFilterLineEdit[source]

Bases: QLineEdit

__init__(parent: QWidget | None = None, nullValue: str | None = '')

Constructor for QgsFilterLineEdit.

Parameters:
  • parent (Optional[QWidget] = None) – parent widget

  • nullValue (Optional[str] = '') – string for representing null values

class ClearMode

Bases: int

ClearToDefault = 1
ClearToNull = 0
clearMode(self) QgsFilterLineEdit.ClearMode[source]

Returns the clear mode for the widget. The clear mode defines the behavior of the widget when its value is cleared. This defaults to ClearToNull.

See also

setClearMode()

Return type:

QgsFilterLineEdit.ClearMode

virtual clearValue(self)[source]

Clears the widget and resets it to the null value.

See also

nullValue()

signal cleared[source]

Emitted when the widget is cleared

See also

clearValue()

defaultValue(self) str[source]

Returns the default value for the widget. The default value is a value which the widget will be reset to if it is cleared and the clearMode() is equal to ClearToDefault.

See also

clearMode()

Return type:

str

virtual event(self, event: QEvent | None) bool[source]

Reimplemented to enable/disable the clear action depending on read-only status

Parameters:

event (Optional[QEvent])

Return type:

bool

hasStateStored(self) bool[source]

Returns if a state is already saved

Added in version 3.14.

Return type:

bool

isNull(self) bool[source]

Determine if the current text represents null.

Return type:

bool

Returns:

True if the widget’s value is null.

See also

nullValue()

nullValue(self) str[source]

Returns the string used for representing null values in the widget.

See also

setNullValue()

See also

isNull()

Return type:

str

restoreState(self)[source]

Restores the current state of the line edit (selection and cursor position)

Added in version 3.14.

selectOnFocus(self) bool[source]

Will select all text when this widget receives the focus.

Return type:

bool

signal selectOnFocusChanged[source]

Will select all text when this widget receives the focus.

setClearMode(self, mode: QgsFilterLineEdit.ClearMode)[source]

Sets the clear mode for the widget. The clear mode defines the behavior of the widget when its value is cleared. This defaults to ClearToNull.

See also

clearMode()

Parameters:

mode (QgsFilterLineEdit.ClearMode)

setDefaultValue(self, defaultValue: str | None)[source]

Sets the default value for the widget. The default value is a value which the widget will be reset to if it is cleared and the clearMode() is equal to ClearToDefault.

Parameters:

defaultValue (Optional[str]) – default value

See also

defaultValue()

See also

clearMode()

setNullValue(self, nullValue: str | None)[source]

Sets the string representation for null values in the widget. This does not affect the values returned for null values by value(), rather it only affects the text that is shown to users when the widget’s value is null.

Parameters:

nullValue (Optional[str]) – string to show when widget’s value is null

See also

nullValue()

setSelectOnFocus(self, selectOnFocus: bool)[source]

Will select all text when this widget receives the focus.

Parameters:

selectOnFocus (bool)

setShowClearButton(self, visible: bool)[source]

Sets whether the widget’s clear button is visible.

Parameters:

visible (bool) – set to False to hide the clear button

setShowSearchIcon(self, visible: bool)[source]

Define if a search icon shall be shown on the left of the image when no text is entered

Parameters:

visible (bool) – set to False to hide the search icon

setShowSpinner(self, showSpinner: bool)[source]

Show a spinner icon. This can be used for search boxes to indicate that something is going on in the background.

Parameters:

showSpinner (bool)

setValue(self, value: str | None)[source]

Sets the current text for the widget with support for handling null values.

Parameters:

value (Optional[str]) – The text to set. If a null string is provided, the text shown in the widget will be set to the current nullValue().

See also

value()

showClearButton(self) bool[source]

Returns True if the widget’s clear button is visible.

Return type:

bool

showSearchIcon(self) bool[source]

Returns if a search icon shall be shown on the left of the image when no text is entered

Return type:

bool

showSpinner(self) bool[source]

Show a spinner icon. This can be used for search boxes to indicate that something is going on in the background.

Return type:

bool

signal showSpinnerChanged[source]

Show a spinner icon. This can be used for search boxes to indicate that something is going on in the background.

storeState(self)[source]

Stores the current state of the line edit (selection and cursor position)

Added in version 3.14.

value(self) str[source]

Returns the text of this edit with support for handling null values. If the text in the widget matches the current nullValue() then the returned value will be a null string.

Return type:

str

Returns:

Current text (or null string if it matches the nullValue() property )

See also

setValue()

signal valueChanged(value: str)[source]

Same as textChanged() but with support for null values.

Parameters:

value (str) – The current text or null string if it matches the nullValue() property.