QGIS API Documentation  3.13.0-Master (740be229cb)
qgsexpressionbuilderdialog.cpp
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1 /***************************************************************************
2  qgisexpressionbuilderdialog.h - A generic expression string builder dialog.
3  --------------------------------------
4  Date : 29-May-2011
5  Copyright : (C) 2011 by Nathan Woodrow
6  Email : woodrow.nathan at gmail dot com
7  ***************************************************************************
8  * *
9  * This program is free software; you can redistribute it and/or modify *
10  * it under the terms of the GNU General Public License as published by *
11  * the Free Software Foundation; either version 2 of the License, or *
12  * (at your option) any later version. *
13  * *
14  ***************************************************************************/
15 
17 #include "qgssettings.h"
18 #include "qgsguiutils.h"
19 #include "qgsgui.h"
20 
21 QgsExpressionBuilderDialog::QgsExpressionBuilderDialog( QgsVectorLayer *layer, const QString &startText, QWidget *parent, const QString &key, const QgsExpressionContext &context )
22  : QDialog( parent )
23  , mRecentKey( key )
24 {
25  setupUi( this );
27 
28  connect( builder, &QgsExpressionBuilderWidget::parserErrorChanged, this, &QgsExpressionBuilderDialog::syncOkButtonEnabledState );
29  connect( builder, &QgsExpressionBuilderWidget::evalErrorChanged, this, &QgsExpressionBuilderDialog::syncOkButtonEnabledState );
30 
31  builder->setExpressionContext( context );
32  builder->setLayer( layer );
33  builder->setExpressionText( startText );
34  builder->expressionTree()->loadRecent( mRecentKey );
35  builder->expressionTree()->loadUserExpressions( );
36 
37  connect( buttonBox, &QDialogButtonBox::helpRequested, this, &QgsExpressionBuilderDialog::showHelp );
38 }
39 
41 {
42  return builder;
43 }
44 
46 {
47  builder->setExpressionText( text );
48 }
49 
51 {
52  return builder->expressionText();
53 }
54 
56 {
57  return builder->expectedOutputFormat();
58 }
59 
61 {
62  builder->setExpectedOutputFormat( expected );
63 }
64 
66 {
67  return builder->expressionContext();
68 }
69 
71 {
72  builder->setExpressionContext( context );
73 }
74 
76 {
77  QDialog::done( r );
78 }
79 
81 {
82  builder->expressionTree()->saveToRecent( builder->expressionText(), mRecentKey );
83  QDialog::accept();
84 }
85 
87 {
88  // Store in child widget only.
89  builder->setGeomCalculator( da );
90 }
91 
93 {
94  return mAllowEvalErrors;
95 }
96 
98 {
99  if ( allowEvalErrors == mAllowEvalErrors )
100  return;
101 
102  mAllowEvalErrors = allowEvalErrors;
103  syncOkButtonEnabledState();
104  emit allowEvalErrorsChanged();
105 }
106 
107 void QgsExpressionBuilderDialog::showHelp()
108 {
109  QgsHelp::openHelp( QStringLiteral( "working_with_vector/expression.html" ) );
110 }
111 
112 void QgsExpressionBuilderDialog::syncOkButtonEnabledState()
113 {
114  QPushButton *okButton = buttonBox->button( QDialogButtonBox::Ok );
115 
116  if ( builder->parserError() )
117  okButton->setEnabled( false );
118  else if ( !builder->evalError() || mAllowEvalErrors )
119  okButton->setEnabled( true );
120  else
121  okButton->setEnabled( true );
122 }
void setExpressionText(const QString &text)
void setExpectedOutputFormat(const QString &expected)
Set the expected format string, which is shown in the dialog.
QgsExpressionBuilderDialog(QgsVectorLayer *layer, const QString &startText=QString(), QWidget *parent SIP_TRANSFERTHIS=nullptr, const QString &key="generic", const QgsExpressionContext &context=QgsExpressionContext())
void evalErrorChanged()
Will be set to true if the current expression text reported an eval error with the context...
QgsExpressionBuilderWidget * expressionBuilder()
The builder widget that is used by the dialog.
QgsExpressionContext expressionContext() const
Returns the expression context for the dialog.
void setAllowEvalErrors(bool allowEvalErrors)
Allow accepting expressions with evaluation errors.
void allowEvalErrorsChanged()
Allow accepting expressions with evaluation errors.
Expression contexts are used to encapsulate the parameters around which a QgsExpression should be eva...
void setExpressionContext(const QgsExpressionContext &context)
Sets the expression context for the dialog.
void setGeomCalculator(const QgsDistanceArea &da)
Sets geometry calculator used in distance/area calculations.
A general purpose distance and area calculator, capable of performing ellipsoid based calculations...
A reusable widget that can be used to build a expression string.
void done(int r) override
Is called when the dialog get accepted or rejected Used to save geometry.
static void enableAutoGeometryRestore(QWidget *widget, const QString &key=QString())
Register the widget to allow its position to be automatically saved and restored when open and closed...
Definition: qgsgui.cpp:133
static void openHelp(const QString &key)
Opens help topic for the given help key using default system web browser.
Definition: qgshelp.cpp:36
QString expectedOutputFormat()
Returns the expected format string, which is shown in the dialog.
void parserErrorChanged()
Will be set to true if the current expression text reported a parser error with the context...
bool allowEvalErrors() const
Allow accepting invalid expressions.
Represents a vector layer which manages a vector based data sets.