QGIS API Documentation  3.13.0-Master (740be229cb)
qgslegendfilterbutton.cpp
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1 /***************************************************************************
2  qgslegendfilterbutton.h - QToolButton for legend filter by map content
3  --------------------------------------
4  Date : June 2015
5  Copyright : (C) 2015 by Hugo Mercier at Oslandia
6  Email : hugo dot mercier at oslandia 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 
16 #include "qgslegendfilterbutton.h"
17 
18 #include <QMenu>
19 #include <QAction>
20 
21 #include "qgsapplication.h"
23 
25  : QToolButton( parent )
26 
27 {
28  mMenu = new QMenu( this );
29  mSetExpressionAction = new QAction( tr( "Edit Filter Expression…" ), mMenu );
30  connect( mSetExpressionAction, &QAction::triggered, this, &QgsLegendFilterButton::onSetLegendFilterExpression );
31 
32  mClearExpressionAction = new QAction( tr( "Clear Filter Expression" ), mMenu );
33  connect( mClearExpressionAction, &QAction::triggered, this, &QgsLegendFilterButton::onClearFilterExpression );
34  mClearExpressionAction->setEnabled( false );
35 
36  mMenu->addAction( mSetExpressionAction );
37  mMenu->addAction( mClearExpressionAction );
38 
39  setCheckable( true );
40  setIcon( QgsApplication::getThemeIcon( QStringLiteral( "/mIconExpressionFilter.svg" ) ) );
41  setPopupMode( QToolButton::MenuButtonPopup );
42 
43  setMenu( mMenu );
44 
45  connect( this, &QAbstractButton::toggled, this, &QgsLegendFilterButton::onToggle );
46 }
47 
48 void QgsLegendFilterButton::onToggle( bool checked )
49 {
50  if ( checked && expressionText().isEmpty() )
51  {
52  // show the dialog if the current expression is empty
53  blockSignals( true );
54  onSetLegendFilterExpression();
55  blockSignals( false );
56  }
57 }
58 
59 void QgsLegendFilterButton::onSetLegendFilterExpression()
60 {
61  QgsExpressionBuilderDialog dlg( mLayer, mExpression );
62  if ( dlg.exec() )
63  {
65 
66  bool emitSignal = false;
67  if ( !expressionText().isEmpty() )
68  {
69  emitSignal = isChecked();
70  setChecked( true );
71  }
72  else
73  {
74  emitSignal = !isChecked();
75  setChecked( false );
76  }
77  if ( emitSignal )
78  emit toggled( isChecked() );
79  }
80 }
81 
82 void QgsLegendFilterButton::onClearFilterExpression()
83 {
84  mClearExpressionAction->setEnabled( false );
85  setExpressionText( QString() );
86 
87  setChecked( false );
88 }
89 
90 void QgsLegendFilterButton::updateMenu()
91 {
92  if ( !mExpression.isEmpty() )
93  {
94  mClearExpressionAction->setEnabled( true );
95  mSetExpressionAction->setText( QString( tr( "Edit filter expression (current: %1)" ) ).arg( mExpression ) );
96  }
97  else
98  {
99  mClearExpressionAction->setEnabled( false );
100  mSetExpressionAction->setText( tr( "Edit filter expression" ) );
101  }
102 }
103 
105 {
106  return mExpression;
107 }
108 
109 void QgsLegendFilterButton::setExpressionText( const QString &expression )
110 {
111  mExpression = expression;
112  updateMenu();
113 }
114 
116 {
117  return mLayer;
118 }
119 
121 {
122  mLayer = layer;
123 }
QgsVectorLayer * vectorLayer() const
Returns the current associated vectorLayer May be nullptr.
static QIcon getThemeIcon(const QString &name)
Helper to get a theme icon.
QString expressionText() const
Returns the current text used as filter expression.
void setExpressionText(const QString &expression)
Sets the current text used as filter expression.
QgsLegendFilterButton(QWidget *parent=nullptr)
Construct a new filter legend button.
Represents a vector layer which manages a vector based data sets.
void setVectorLayer(QgsVectorLayer *layer)
Sets the associated vectorLayer May be nullptr.
A generic dialog for building expression strings.