QGIS API Documentation  3.26.3-Buenos Aires (65e4edfdad)
qgsrasterbandcombobox.cpp
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1 /***************************************************************************
2  qgsrasterbandcombobox.cpp
3  -------------------------
4  begin : May 2017
5  copyright : (C) 2017 by Nyall Dawson
6  email : nyall dot dawson 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 
16 #include "qgsrasterbandcombobox.h"
17 #include "qgsrasterlayer.h"
18 #include "qgsrasterdataprovider.h"
19 
21  : QComboBox( parent )
22  , mNotSetString( tr( "Not set" ) )
23 {
24  connect( this, static_cast<void ( QComboBox::* )( int )>( &QComboBox::currentIndexChanged ), this, [ = ]
25  {
26  if ( mLayer && mLayer->isValid() )
27  {
28  const int newBand = currentIndex() >= 0 ? currentData().toInt() : -1 ;
29  if ( newBand != mPrevBand )
30  {
31  emit bandChanged( currentIndex() >= 0 ? currentData().toInt() : -1 );
32  mPrevBand = newBand;
33  }
34  }
35  } );
36 
37  connect( this, &QComboBox::currentTextChanged, this, [ = ]( const QString & value )
38  {
39  if ( !mLayer || !mLayer->isValid() )
40  {
41  bool ok = false;
42  const int band = value.toInt( &ok );
43  if ( ok && band != mPrevBand )
44  {
45  emit bandChanged( band );
46  mPrevBand = band;
47  }
48  else if ( mShowNotSet && mPrevBand != -1 )
49  {
50  emit bandChanged( -1 );
51  mPrevBand = -1;
52  }
53  }
54  } );
55 
56  // default to editable, until a layer is set
57  setEditable( true );
58 }
59 
61 {
62  return mLayer;
63 }
64 
66 {
67  if ( !mLayer || !mLayer->dataProvider() || !mLayer->isValid() )
68  {
69  bool ok = false;
70  const int band = currentText().toInt( &ok );
71  if ( ok )
72  return band;
73  return -1;
74  }
75  else
76  {
77  if ( currentIndex() < 0 )
78  return -1;
79 
80  return currentData().toInt();
81  }
82 }
83 
85 {
86  const int oldBand = currentBand();
87 
88  QgsRasterLayer *rl = qobject_cast< QgsRasterLayer * >( layer );
89  mLayer = rl;
90 
91  blockSignals( true );
92  clear();
93 
94  if ( mShowNotSet )
95  addItem( mNotSetString, -1 );
96 
97  if ( mLayer )
98  {
99  QgsRasterDataProvider *provider = mLayer->dataProvider();
100  if ( provider && mLayer->isValid() )
101  {
102  setEditable( false );
103  //fill available bands into combo box
104  const int nBands = provider->bandCount();
105  for ( int i = 1; i <= nBands; ++i ) //band numbering seem to start at 1
106  {
107  addItem( displayBandName( provider, i ), i );
108  }
109  }
110  else
111  {
112  setEditable( true );
113  }
114  }
115  else
116  {
117  setEditable( true );
118  }
119 
120  if ( oldBand >= 0 )
121  setBand( oldBand );
122  else
123  setCurrentIndex( 0 );
124 
125  blockSignals( false );
126  const int newBand = currentBand();
127  //if ( newBand != oldBand )
128  // emit bandChanged( newBand );
129  mPrevBand = newBand;
130 }
131 
133 {
134  if ( !mLayer || !mLayer->dataProvider() || !mLayer->isValid() )
135  {
136  if ( band < 0 )
137  {
138  setCurrentIndex( -1 );
139  if ( mPrevBand != -1 )
140  emit bandChanged( -1 );
141  }
142  else
143  setCurrentText( QString::number( band ) );
144  }
145  else
146  {
147  setCurrentIndex( findData( band ) );
148  }
149  mPrevBand = band;
150 }
151 
153 {
154  return mShowNotSet;
155 }
156 
157 void QgsRasterBandComboBox::setShowNotSetOption( bool show, const QString &string )
158 {
159  mShowNotSet = show;
160  mNotSetString = string.isEmpty() ? tr( "Not set" ) : string;
161  setLayer( mLayer );
162 }
163 
165 {
166  if ( !provider )
167  return QString();
168 
169  return provider->displayBandName( band );
170 }
QgsRasterBandComboBox::setShowNotSetOption
void setShowNotSetOption(bool show, const QString &string=QString())
Sets whether the combo box should show the "not set" option.
Definition: qgsrasterbandcombobox.cpp:157
QgsRasterBandComboBox::setBand
void setBand(int band)
Sets the current band number selected in the combobox.
Definition: qgsrasterbandcombobox.cpp:132
QgsRasterBandComboBox::bandChanged
void bandChanged(int band)
Emitted when the currently selected band changes.
qgsrasterlayer.h
qgsrasterbandcombobox.h
QgsRasterInterface::displayBandName
QString displayBandName(int bandNumber) const
Generates a friendly, descriptive name for the specified bandNumber.
Definition: qgsrasterinterface.cpp:636
QgsRasterBandComboBox::setLayer
void setLayer(QgsMapLayer *layer)
Sets the raster layer for which the bands are listed in the combobox.
Definition: qgsrasterbandcombobox.cpp:84
QgsRasterBandComboBox::QgsRasterBandComboBox
QgsRasterBandComboBox(QWidget *parent=nullptr)
Constructor for QgsRasterBandComboBox.
Definition: qgsrasterbandcombobox.cpp:20
QgsRasterLayer
Represents a raster layer.
Definition: qgsrasterlayer.h:76
QgsRasterBandComboBox::band
int band
Definition: qgsrasterbandcombobox.h:37
QgsRasterBandComboBox::isShowingNotSetOption
bool isShowingNotSetOption() const
Returns true if the combo box is showing the "not set" option.
Definition: qgsrasterbandcombobox.cpp:152
QgsMapLayer
Base class for all map layer types. This is the base class for all map layer types (vector,...
Definition: qgsmaplayer.h:72
QgsRasterBandComboBox::currentBand
int currentBand() const
Returns the current band number selected in the combobox, or -1 if no band is selected.
Definition: qgsrasterbandcombobox.cpp:65
QgsRasterInterface::bandCount
virtual int bandCount() const =0
Gets number of bands.
QgsRasterDataProvider
Base class for raster data providers.
Definition: qgsrasterdataprovider.h:88
QgsRasterBandComboBox::layer
QgsRasterLayer * layer() const
Returns the layer currently associated with the combobox.
Definition: qgsrasterbandcombobox.cpp:60
qgsrasterdataprovider.h
QgsRasterBandComboBox::displayBandName
static QString displayBandName(QgsRasterDataProvider *provider, int band)
Returns a user-friendly band name for the specified band.
Definition: qgsrasterbandcombobox.cpp:164