QGIS API Documentation 3.27.0-Master (f261cc1f8b)
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
17#include "qgsrasterlayer.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
157void 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}
Base class for all map layer types.
Definition: qgsmaplayer.h:73
QgsRasterLayer * layer() const
Returns the layer currently associated with the combobox.
void bandChanged(int band)
Emitted when the currently selected band changes.
void setShowNotSetOption(bool show, const QString &string=QString())
Sets whether the combo box should show the "not set" option.
int currentBand() const
Returns the current band number selected in the combobox, or -1 if no band is selected.
QgsRasterBandComboBox(QWidget *parent=nullptr)
Constructor for QgsRasterBandComboBox.
void setLayer(QgsMapLayer *layer)
Sets the raster layer for which the bands are listed in the combobox.
static QString displayBandName(QgsRasterDataProvider *provider, int band)
Returns a user-friendly band name for the specified band.
bool isShowingNotSetOption() const
Returns true if the combo box is showing the "not set" option.
void setBand(int band)
Sets the current band number selected in the combobox.
Base class for raster data providers.
virtual int bandCount() const =0
Gets number of bands.
QString displayBandName(int bandNumber) const
Generates a friendly, descriptive name for the specified bandNumber.
Represents a raster layer.