/************************************************************************
 * This file has been generated automatically from                      *
 *                                                                      *
 * src/gui/qgsexpressionpreviewwidget.h                                 *
 *                                                                      *
 * Do not edit manually ! Edit header and run scripts/sipify.py again   *
 ************************************************************************/







class QgsExpressionPreviewWidget : QWidget
{
%Docstring(signature="appended")
A widget for previewing an expression result.

If the layer is set, one can browse across features to see the different
outputs.

.. versionadded:: 3.14
%End

%TypeHeaderCode
#include "qgsexpressionpreviewwidget.h"
%End
  public:
    explicit QgsExpressionPreviewWidget( QWidget *parent = 0 );
%Docstring
Constructor
%End

    void setLayer( QgsVectorLayer *layer );
%Docstring
Sets the layer used in the preview
%End


    void setCustomPreviewGenerator( const QString &label, const QList<QPair<QString, QVariant>> &choices, SIP_PYCALLABLE );
%Docstring
Sets the widget to run using a custom preview generator.

In this mode, the widget will call a callback function to generate a new
:py:class:`QgsExpressionContext` as the previewed object changes. This
can be used to provide custom preview values for different objects (i.e.
for objects which aren't vector layer features).

:param label: The label to display for the combo box presenting choices
              of objects. This should be a representative name, eg
              "Band" if the widget is showing choices of raster layer
              bands
:param choices: A list of choices to present to the user. Each choice is
                a pair of a human-readable label and a QVariant
                representing the object to preview.
:param previewContextGenerator: A function which takes a QVariant
                                representing the object to preview, and
                                returns a
                                :py:class:`QgsExpressionContext` to use
                                for previewing the object.

.. versionadded:: 3.38
%End
%MethodCode
    Py_XINCREF( a2 );
    Py_BEGIN_ALLOW_THREADS
      sipCpp->setCustomPreviewGenerator( *a0, *a1, [a2]( const QVariant &value ) -> QgsExpressionContext {
        QgsExpressionContext res;
        SIP_BLOCK_THREADS
        PyObject *s = sipCallMethod( NULL, a2, "D", &value, sipType_QVariant, NULL );
        int state;
        int sipIsError = 0;
        QgsExpressionContext *t1 = reinterpret_cast<QgsExpressionContext *>( sipConvertToType( s, sipType_QgsExpressionContext, 0, SIP_NOT_NONE, &state, &sipIsError ) );
        if ( sipIsError == 0 )
        {
          res = QgsExpressionContext( *t1 );
        }
        sipReleaseType( t1, sipType_QgsExpressionContext, state );
        SIP_UNBLOCK_THREADS
        return res;
      } );

    Py_END_ALLOW_THREADS
%End

    void setExpressionText( const QString &expression );
%Docstring
Sets the expression
%End

    QgsExpressionContext expressionContext() const;
%Docstring
Returns the expression context for the widget. The context is used for
the expression preview result and for populating the list of available
functions and variables.

.. seealso:: :py:func:`setExpressionContext`
%End

    void setExpressionContext( const QgsExpressionContext &context );
%Docstring
Sets the expression context for the widget. The context is used for the
expression preview result and to populate the list of available
functions and variables.

:param context: expression context
%End

    void setGeomCalculator( const QgsDistanceArea &da );
%Docstring
Sets geometry calculator used in distance/area calculations.
%End

    bool evalError() const;
%Docstring
Will be set to ``True`` if the current expression text reported an eval
error with the context.
%End

    bool parserError() const;
%Docstring
Will be set to ``True`` if the current expression text reports a parser
error with the context.
%End

    const QgsExpressionNode *rootNode() const;
%Docstring
Returns the root node of the expression
%End

    QList<QgsExpression::ParserError> parserErrors() const;
%Docstring
Returns the expression parser errors
%End

    QString currentPreviewText() const;
%Docstring
Returns the current expression result preview text.

.. versionadded:: 3.38
%End

  signals:

    void expressionParsed( bool isValid );
%Docstring
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.

:param isValid: Is ``True`` if the expression the user has typed is
                valid.
%End

    void evalErrorChanged();
%Docstring
Will be set to ``True`` if the current expression text reported an eval
error with the context.
%End

    void parserErrorChanged();
%Docstring
Will be set to ``True`` if the current expression text reported a parser
error with the context.
%End

    void toolTipChanged( const QString &toolTip );
%Docstring
Emitted whenever the tool tip changed
%End

  public slots:
    void setCurrentFeature( const QgsFeature &feature );
%Docstring
sets the current feature used
%End


};

/************************************************************************
 * This file has been generated automatically from                      *
 *                                                                      *
 * src/gui/qgsexpressionpreviewwidget.h                                 *
 *                                                                      *
 * Do not edit manually ! Edit header and run scripts/sipify.py again   *
 ************************************************************************/