qgscolorrampshaderwidget.cpp

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/***************************************************************************
                         qgscolorrampshaderwidget.cpp
                         ----------------------------
    begin                : Jun 2018
    copyright            : (C) 2018 by Peter Petrik
    email                : zilolv at gmail dot com
 ***************************************************************************/
 
/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#include "qgscolorrampshaderwidget.h"
 
#include "qgscolordialog.h"
#include "qgscolorramp.h"
#include "qgscolorrampbutton.h"
#include "qgscolorramplegendnodewidget.h"
#include "qgsfileutils.h"
#include "qgsguiutils.h"
#include "qgslocaleawarenumericlineeditdelegate.h"
#include "qgsrasterdataprovider.h"
#include "qgsrasterrendererutils.h"
#include "qgssettings.h"
#include "qgstreewidgetitem.h"
 
#include <QCursor>
#include <QFileDialog>
#include <QInputDialog>
#include <QMenu>
#include <QMessageBox>
#include <QPushButton>
#include <QString>
#include <QTextStream>
#include <QTreeView>
 
#include "moc_qgscolorrampshaderwidget.cpp"
 
using namespace Qt::StringLiterals;
 
QgsColorRampShaderWidget::QgsColorRampShaderWidget( QWidget *parent )
  : QWidget( parent )
{
  QgsSettings settings;
 
  setupUi( this );
  mLoadFromBandButton->setVisible( false ); // only for raster version
 
  connect( mAddEntryButton, &QPushButton::clicked, this, &QgsColorRampShaderWidget::mAddEntryButton_clicked );
  connect( mDeleteEntryButton, &QPushButton::clicked, this, &QgsColorRampShaderWidget::mDeleteEntryButton_clicked );
  connect( mLoadFromBandButton, &QPushButton::clicked, this, &QgsColorRampShaderWidget::mLoadFromBandButton_clicked );
  connect( mLoadFromFileButton, &QPushButton::clicked, this, &QgsColorRampShaderWidget::mLoadFromFileButton_clicked );
  connect( mExportToFileButton, &QPushButton::clicked, this, &QgsColorRampShaderWidget::mExportToFileButton_clicked );
  connect( mUnitLineEdit, &QLineEdit::textEdited, this, &QgsColorRampShaderWidget::mUnitLineEdit_textEdited );
  connect( mColormapTreeWidget, &QTreeWidget::itemDoubleClicked, this, &QgsColorRampShaderWidget::mColormapTreeWidget_itemDoubleClicked );
  connect( mColorInterpolationComboBox, static_cast<void ( QComboBox::* )( int )>( &QComboBox::currentIndexChanged ), this, &QgsColorRampShaderWidget::mColorInterpolationComboBox_currentIndexChanged );
  connect( mClassificationModeComboBox, static_cast<void ( QComboBox::* )( int )>( &QComboBox::currentIndexChanged ), this, &QgsColorRampShaderWidget::mClassificationModeComboBox_currentIndexChanged );
 
  connect( mLegendSettingsButton, &QPushButton::clicked, this, &QgsColorRampShaderWidget::showLegendSettings );
 
  contextMenu = new QMenu( tr( "Options" ), this );
  contextMenu->addAction( tr( "Change Color…" ), this, &QgsColorRampShaderWidget::changeColor );
  contextMenu->addAction( tr( "Change Opacity…" ), this, &QgsColorRampShaderWidget::changeOpacity );
 
  mColormapTreeWidget->setItemDelegateForColumn( ColorColumn, new QgsColorSwatchDelegate( this ) );
  mValueDelegate = new QgsLocaleAwareNumericLineEditDelegate( Qgis::DataType::UnknownDataType, this );
  mColormapTreeWidget->setItemDelegateForColumn( ValueColumn, mValueDelegate );
 
  mColormapTreeWidget->setColumnWidth( ColorColumn, Qgis::UI_SCALE_FACTOR * fontMetrics().horizontalAdvance( 'X' ) * 6.6 );
 
  mColormapTreeWidget->setContextMenuPolicy( Qt::CustomContextMenu );
  mColormapTreeWidget->setSelectionMode( QAbstractItemView::ExtendedSelection );
  connect( mColormapTreeWidget, &QTreeView::customContextMenuRequested, this, [this]( QPoint ) { contextMenu->exec( QCursor::pos() ); } );
 
  QString defaultPalette = settings.value( u"Raster/defaultPalette"_s, "" ).toString();
  btnColorRamp->setColorRampFromName( defaultPalette );
 
  mColorInterpolationComboBox->addItem( tr( "Discrete" ), QVariant::fromValue( Qgis::ShaderInterpolationMethod::Discrete ) );
  mColorInterpolationComboBox->addItem( tr( "Linear" ), QVariant::fromValue( Qgis::ShaderInterpolationMethod::Linear ) );
  mColorInterpolationComboBox->addItem( tr( "Exact" ), QVariant::fromValue( Qgis::ShaderInterpolationMethod::Exact ) );
  mColorInterpolationComboBox->setCurrentIndex( mColorInterpolationComboBox->findData( QVariant::fromValue( Qgis::ShaderInterpolationMethod::Linear ) ) );
 
  mClassificationModeComboBox->addItem( tr( "Continuous" ), QVariant::fromValue( Qgis::ShaderClassificationMethod::Continuous ) );
  mClassificationModeComboBox->addItem( tr( "Equal Interval" ), QVariant::fromValue( Qgis::ShaderClassificationMethod::EqualInterval ) );
  // Quantile added only on demand
  mClassificationModeComboBox->setCurrentIndex( mClassificationModeComboBox->findData( QVariant::fromValue( Qgis::ShaderClassificationMethod::Continuous ) ) );
 
  mNumberOfEntriesSpinBox->setValue( 5 ); // some default
 
  mClassificationModeComboBox_currentIndexChanged( 0 );
 
  resetClassifyButton();
 
  connect( mClassificationModeComboBox, static_cast<void ( QComboBox::* )( int )>( &QComboBox::currentIndexChanged ), this, &QgsColorRampShaderWidget::classify );
  connect( mColorInterpolationComboBox, static_cast<void ( QComboBox::* )( int )>( &QComboBox::currentIndexChanged ), this, &QgsColorRampShaderWidget::classify );
  connect( mClassifyButton, &QPushButton::clicked, this, &QgsColorRampShaderWidget::classify );
  connect( btnColorRamp, &QgsColorRampButton::colorRampChanged, this, &QgsColorRampShaderWidget::applyColorRamp );
  connect( mNumberOfEntriesSpinBox, static_cast<void ( QSpinBox::* )( int )>( &QSpinBox::valueChanged ), this, &QgsColorRampShaderWidget::classify );
  connect( mClipCheckBox, &QAbstractButton::toggled, this, &QgsColorRampShaderWidget::widgetChanged );
  connect( mLabelPrecisionSpinBox, qOverload<int>( &QSpinBox::valueChanged ), this, [this]( int ) {
    autoLabel();
 
    if ( !mBlockChanges )
      emit widgetChanged();
  } );
}
 
QgsColorRampShaderWidget::~QgsColorRampShaderWidget() = default;
 
void QgsColorRampShaderWidget::initializeForUseWithRasterLayer()
{
  Q_ASSERT( mClassificationModeComboBox->findData( QVariant::fromValue( Qgis::ShaderClassificationMethod::Quantile ) ) < 0 );
  mClassificationModeComboBox->addItem( tr( "Quantile" ), QVariant::fromValue( Qgis::ShaderClassificationMethod::Quantile ) );
}
 
void QgsColorRampShaderWidget::setRasterDataProvider( QgsRasterDataProvider *dp )
{
  mRasterDataProvider = dp;
  mLoadFromBandButton->setVisible( static_cast<bool>( mRasterDataProvider ) ); // only for raster version
}
 
void QgsColorRampShaderWidget::setRasterBand( int band )
{
  mBand = band;
  // Assume double by default
  Qgis::DataType dataType { ( mRasterDataProvider && mBand > 0 ) ? mRasterDataProvider->dataType( mBand ) : Qgis::DataType::Float64 };
 
  // Set the maximum number of digits in the precision spin box
  const int maxDigits { QgsGuiUtils::significantDigits( dataType ) };
  mLabelPrecisionSpinBox->setMaximum( maxDigits );
  mValueDelegate->setDataType( dataType );
}
 
void QgsColorRampShaderWidget::setExtent( const QgsRectangle &extent )
{
  mExtent = extent;
}
 
QgsColorRampShader QgsColorRampShaderWidget::shader() const
{
  QgsColorRampShader colorRampShader( mMin, mMax );
  colorRampShader.setLabelPrecision( mLabelPrecisionSpinBox->value() );
  colorRampShader.setColorRampType( mColorInterpolationComboBox->currentData().value<Qgis::ShaderInterpolationMethod>() );
  colorRampShader.setClassificationMode( mClassificationModeComboBox->currentData().value<Qgis::ShaderClassificationMethod>() );
  colorRampShader.setClip( mClipCheckBox->isChecked() );
 
  //iterate through mColormapTreeWidget and set colormap info of layer
  QList<QgsColorRampShader::ColorRampItem> colorRampItems;
  int topLevelItemCount = mColormapTreeWidget->topLevelItemCount();
  QTreeWidgetItem *currentItem = nullptr;
  for ( int i = 0; i < topLevelItemCount; ++i )
  {
    currentItem = mColormapTreeWidget->topLevelItem( i );
    if ( !currentItem )
    {
      continue;
    }
    QgsColorRampShader::ColorRampItem newColorRampItem;
    newColorRampItem.value = currentItem->data( ValueColumn, Qt::ItemDataRole::DisplayRole ).toDouble();
    newColorRampItem.color = currentItem->data( ColorColumn, Qt::ItemDataRole::EditRole ).value<QColor>();
    newColorRampItem.label = currentItem->text( LabelColumn );
    colorRampItems.append( newColorRampItem );
  }
  // sort the shader items
  std::sort( colorRampItems.begin(), colorRampItems.end() );
  colorRampShader.setColorRampItemList( colorRampItems );
 
  if ( !btnColorRamp->isNull() )
  {
    colorRampShader.setSourceColorRamp( btnColorRamp->colorRamp() );
  }
 
  colorRampShader.setLegendSettings( new QgsColorRampLegendNodeSettings( mLegendSettings ) );
  return colorRampShader;
}
 
void QgsColorRampShaderWidget::autoLabel()
{
  mColormapTreeWidget->sortItems( ValueColumn, Qt::AscendingOrder );
 
#ifdef QGISDEBUG
  dumpClasses();
#endif
 
  const QString unit = mUnitLineEdit->text();
  int topLevelItemCount = mColormapTreeWidget->topLevelItemCount();
 
  QTreeWidgetItem *currentItem = nullptr;
  for ( int i = 0; i < topLevelItemCount; ++i )
  {
    currentItem = mColormapTreeWidget->topLevelItem( i );
    //If the item is null or does not have a pixel values set, skip
    if ( !currentItem || currentItem->data( ValueColumn, Qt::ItemDataRole::DisplayRole ).toString().isEmpty() )
    {
      continue;
    }
 
    const QString lbl = createLabel( currentItem, i, unit );
 
    if ( currentItem->text( LabelColumn ).isEmpty() || currentItem->text( LabelColumn ) == lbl || currentItem->foreground( LabelColumn ).color() == QColor( Qt::gray ) )
    {
      currentItem->setText( LabelColumn, lbl );
      currentItem->setForeground( LabelColumn, QBrush( QColor( Qt::gray ) ) );
    }
  }
}
 
void QgsColorRampShaderWidget::setUnitFromLabels()
{
  QStringList allSuffixes;
  QString label;
  int topLevelItemCount = mColormapTreeWidget->topLevelItemCount();
  QTreeWidgetItem *currentItem = nullptr;
  for ( int i = 0; i < topLevelItemCount; ++i )
  {
    currentItem = mColormapTreeWidget->topLevelItem( i );
    //If the item is null or does not have a pixel values set, skip
    if ( !currentItem || currentItem->text( ValueColumn ).isEmpty() )
    {
      continue;
    }
 
    label = createLabel( currentItem, i, QString() );
 
    if ( currentItem->text( LabelColumn ).startsWith( label ) )
    {
      allSuffixes.append( currentItem->text( LabelColumn ).mid( label.length() ) );
    }
  }
  // find most common suffix
  QStringList suffixes = QStringList( allSuffixes );
  suffixes.removeDuplicates();
  int max = 0;
  QString unit;
  for ( int i = 0; i < suffixes.count(); ++i )
  {
    int n = allSuffixes.count( suffixes[i] );
    if ( n > max )
    {
      max = n;
      unit = suffixes[i];
    }
  }
  // Set this suffix as unit if at least used twice
  if ( max >= 2 )
  {
    mUnitLineEdit->setText( unit );
  }
}
 
#ifdef QGISDEBUG
void QgsColorRampShaderWidget::dumpClasses()
{
  for ( int row = 0; row < mColormapTreeWidget->model()->rowCount(); ++row )
  {
    const auto labelData { mColormapTreeWidget->model()->itemData( mColormapTreeWidget->model()->index( row, LabelColumn ) ) };
    const auto valueData { mColormapTreeWidget->model()->itemData( mColormapTreeWidget->model()->index( row, ValueColumn ) ) };
    QgsDebugMsgLevel( u"Class %1 : %2 %3"_s.arg( row ).arg( labelData[Qt::ItemDataRole::DisplayRole].toString(), valueData[Qt::ItemDataRole::DisplayRole].toString() ), 2 );
  }
}
#endif
 
void QgsColorRampShaderWidget::mAddEntryButton_clicked()
{
  QgsTreeWidgetItemObject *newItem = new QgsTreeWidgetItemObject( mColormapTreeWidget );
  newItem->setData( ValueColumn, Qt::ItemDataRole::DisplayRole, 0 );
  newItem->setData( ColorColumn, Qt::ItemDataRole::EditRole, QColor( Qt::magenta ) );
  newItem->setText( LabelColumn, QString() );
  newItem->setFlags( Qt::ItemIsEnabled | Qt::ItemIsEditable | Qt::ItemIsSelectable );
  connect( newItem, &QgsTreeWidgetItemObject::itemEdited, this, &QgsColorRampShaderWidget::mColormapTreeWidget_itemEdited );
  autoLabel();
 
  loadMinimumMaximumFromTree();
  updateColorRamp();
  emit widgetChanged();
}
 
void QgsColorRampShaderWidget::mDeleteEntryButton_clicked()
{
  QList<QTreeWidgetItem *> itemList;
  itemList = mColormapTreeWidget->selectedItems();
  if ( itemList.isEmpty() )
  {
    return;
  }
 
  const auto constItemList = itemList;
  for ( QTreeWidgetItem *item : constItemList )
  {
    delete item;
  }
 
  loadMinimumMaximumFromTree();
  updateColorRamp();
  emit widgetChanged();
}
 
void QgsColorRampShaderWidget::classify()
{
  std::unique_ptr<QgsColorRamp> ramp( btnColorRamp->colorRamp() );
  if ( !ramp || std::isnan( mMin ) || std::isnan( mMax ) )
  {
    return;
  }
 
  std::unique_ptr<QgsColorRampShader> colorRampShader(
    new QgsColorRampShader( mMin, mMax, ramp.release(), mColorInterpolationComboBox->currentData().value<Qgis::ShaderInterpolationMethod>(), mClassificationModeComboBox->currentData().value<Qgis::ShaderClassificationMethod>() )
  );
 
  // only for Quantile we need band and provider and extent
  colorRampShader->classifyColorRamp( mNumberOfEntriesSpinBox->value(), mBand, mExtent, mRasterDataProvider );
  colorRampShader->setClip( mClipCheckBox->isChecked() );
 
  mColormapTreeWidget->clear();
 
  const QList<QgsColorRampShader::ColorRampItem> colorRampItemList = colorRampShader->colorRampItemList();
  QList<QgsColorRampShader::ColorRampItem>::const_iterator it = colorRampItemList.constBegin();
  for ( ; it != colorRampItemList.end(); ++it )
  {
    QgsTreeWidgetItemObject *newItem = new QgsTreeWidgetItemObject( mColormapTreeWidget );
    newItem->setData( ValueColumn, Qt::ItemDataRole::DisplayRole, it->value );
    newItem->setData( ColorColumn, Qt::ItemDataRole::EditRole, it->color );
    newItem->setText( LabelColumn, QString() ); // Labels will be populated in autoLabel()
    newItem->setFlags( Qt::ItemIsEnabled | Qt::ItemIsEditable | Qt::ItemIsSelectable );
    connect( newItem, &QgsTreeWidgetItemObject::itemEdited, this, &QgsColorRampShaderWidget::mColormapTreeWidget_itemEdited );
  }
 
  mClipCheckBox->setChecked( colorRampShader->clip() );
 
  autoLabel();
  emit widgetChanged();
}
 
void QgsColorRampShaderWidget::mClassificationModeComboBox_currentIndexChanged( int index )
{
  Qgis::ShaderClassificationMethod mode = mClassificationModeComboBox->itemData( index ).value<Qgis::ShaderClassificationMethod>();
  mNumberOfEntriesSpinBox->setEnabled( mode != Qgis::ShaderClassificationMethod::Continuous );
  emit classificationModeChanged( mode );
}
 
void QgsColorRampShaderWidget::updateColorRamp()
{
  std::unique_ptr<QgsColorRamp> ramp( shader().createColorRamp() );
  whileBlocking( btnColorRamp )->setColorRamp( ramp.get() );
}
 
void QgsColorRampShaderWidget::applyColorRamp()
{
  std::unique_ptr<QgsColorRamp> ramp( btnColorRamp->colorRamp() );
  if ( !ramp )
  {
    return;
  }
 
  if ( !btnColorRamp->colorRampName().isEmpty() )
  {
    // Remember last used color ramp
    QgsSettings settings;
    settings.setValue( u"Raster/defaultPalette"_s, btnColorRamp->colorRampName() );
  }
 
  bool enableContinuous = ( ramp->count() > 0 );
  mClassificationModeComboBox->setEnabled( enableContinuous );
  if ( !enableContinuous )
  {
    mClassificationModeComboBox->setCurrentIndex( mClassificationModeComboBox->findData( QVariant::fromValue( Qgis::ShaderClassificationMethod::EqualInterval ) ) );
  }
 
  int topLevelItemCount = mColormapTreeWidget->topLevelItemCount();
  if ( topLevelItemCount > 0 )
  {
    // We need to have valid min/max values here. If we haven't, load from colormap
    double min, max;
    if ( std::isnan( mMin ) || std::isnan( mMax ) )
    {
      colormapMinMax( min, max );
    }
    else
    {
      min = mMin;
      max = mMax;
    }
 
    // if the list values has been customized, maintain pre-existing values
    QTreeWidgetItem *currentItem = nullptr;
    for ( int i = 0; i < topLevelItemCount; ++i )
    {
      currentItem = mColormapTreeWidget->topLevelItem( i );
      if ( !currentItem )
      {
        continue;
      }
 
      double value = currentItem->data( ValueColumn, Qt::ItemDataRole::EditRole ).toDouble();
      double position = ( value - min ) / ( max - min );
      whileBlocking( static_cast<QgsTreeWidgetItemObject *>( currentItem ) )->setData( ColorColumn, Qt::ItemDataRole::EditRole, ramp->color( position ) );
    }
 
    emit widgetChanged();
  }
  else
  {
    classify();
  }
}
 
void QgsColorRampShaderWidget::populateColormapTreeWidget( const QList<QgsColorRampShader::ColorRampItem> &colorRampItems )
{
  mColormapTreeWidget->clear();
  QList<QgsColorRampShader::ColorRampItem>::const_iterator it = colorRampItems.constBegin();
  int i = 0;
  for ( ; it != colorRampItems.constEnd(); ++it )
  {
    QgsTreeWidgetItemObject *newItem = new QgsTreeWidgetItemObject( mColormapTreeWidget );
    newItem->setData( ValueColumn, Qt::ItemDataRole::DisplayRole, it->value );
    newItem->setData( ColorColumn, Qt::ItemDataRole::EditRole, it->color );
    newItem->setText( LabelColumn, it->label );
    newItem->setFlags( Qt::ItemIsEnabled | Qt::ItemIsEditable | Qt::ItemIsSelectable );
    connect( newItem, &QgsTreeWidgetItemObject::itemEdited, this, &QgsColorRampShaderWidget::mColormapTreeWidget_itemEdited );
    ++i;
  }
 
#ifdef QGISDEBUG
  dumpClasses();
#endif
 
  setUnitFromLabels();
 
  // Now we have the suffix
  const QString unit = mUnitLineEdit->text();
  for ( i = 0; i < mColormapTreeWidget->topLevelItemCount(); i++ )
  {
    QgsTreeWidgetItemObject *currentItem { static_cast<QgsTreeWidgetItemObject *>( mColormapTreeWidget->topLevelItem( i ) ) };
    QString lbl { createLabel( currentItem, i, unit ) };
    if ( currentItem->text( LabelColumn ).isEmpty() || currentItem->text( LabelColumn ) == lbl || currentItem->foreground( LabelColumn ).color() == QColor( Qt::gray ) )
    {
      currentItem->setText( LabelColumn, lbl );
      currentItem->setForeground( LabelColumn, QBrush( QColor( Qt::gray ) ) );
    }
  }
}
 
void QgsColorRampShaderWidget::mLoadFromBandButton_clicked()
{
  if ( !mRasterDataProvider )
    return;
 
  QList<QgsColorRampShader::ColorRampItem> colorRampList = mRasterDataProvider->colorTable( mBand );
  if ( !colorRampList.isEmpty() )
  {
    populateColormapTreeWidget( colorRampList );
    mColorInterpolationComboBox->setCurrentIndex( mColorInterpolationComboBox->findData( QVariant::fromValue( Qgis::ShaderInterpolationMethod::Linear ) ) );
  }
  else
  {
    QMessageBox::warning( this, tr( "Load Color Map" ), tr( "The color map for band %1 has no entries." ).arg( mBand ) );
  }
  loadMinimumMaximumFromTree();
  emit widgetChanged();
}
 
void QgsColorRampShaderWidget::mLoadFromFileButton_clicked()
{
  QgsSettings settings;
  QString lastDir = settings.value( u"lastColorMapDir"_s, QDir::homePath() ).toString();
  const QString fileName = QFileDialog::getOpenFileName( this, tr( "Load Color Map from File" ), lastDir, tr( "Textfile (*.txt)" ) );
  if ( fileName.isEmpty() )
    return;
 
  QList<QgsColorRampShader::ColorRampItem> colorRampItems;
  Qgis::ShaderInterpolationMethod type = Qgis::ShaderInterpolationMethod::Linear;
  QStringList errors;
  if ( QgsRasterRendererUtils::parseColorMapFile( fileName, colorRampItems, type, errors ) )
  {
    //clear the current tree
    mColormapTreeWidget->clear();
 
    mColorInterpolationComboBox->setCurrentIndex( mColorInterpolationComboBox->findData( QVariant::fromValue( type ) ) );
 
    populateColormapTreeWidget( colorRampItems );
 
    if ( !errors.empty() )
    {
      QMessageBox::warning( this, tr( "Load Color Map from File" ), tr( "The following lines contained errors\n\n" ) + errors.join( '\n' ) );
    }
  }
  else
  {
    const QString error = tr( "An error occurred while reading the color map\n\n" ) + errors.join( '\n' );
    QMessageBox::warning( this, tr( "Load Color Map from File" ), error );
  }
 
  QFileInfo fileInfo( fileName );
  settings.setValue( u"lastColorMapDir"_s, fileInfo.absoluteDir().absolutePath() );
 
  loadMinimumMaximumFromTree();
  updateColorRamp();
  emit widgetChanged();
}
 
void QgsColorRampShaderWidget::mExportToFileButton_clicked()
{
  QgsSettings settings;
  QString lastDir = settings.value( u"lastColorMapDir"_s, QDir::homePath() ).toString();
  QString fileName = QFileDialog::getSaveFileName( this, tr( "Save Color Map as File" ), lastDir, tr( "Textfile (*.txt)" ) );
  if ( fileName.isEmpty() )
    return;
 
  fileName = QgsFileUtils::ensureFileNameHasExtension( fileName, QStringList() << u"txt"_s );
 
  QList<QgsColorRampShader::ColorRampItem> colorRampItems;
  int topLevelItemCount = mColormapTreeWidget->topLevelItemCount();
  for ( int i = 0; i < topLevelItemCount; ++i )
  {
    QTreeWidgetItem *currentItem = mColormapTreeWidget->topLevelItem( i );
    if ( !currentItem )
    {
      continue;
    }
 
    QgsColorRampShader::ColorRampItem item;
    item.value = currentItem->data( ValueColumn, Qt::ItemDataRole::DisplayRole ).toDouble();
    item.color = currentItem->data( ColorColumn, Qt::ItemDataRole::EditRole ).value<QColor>();
    item.label = currentItem->text( LabelColumn );
    colorRampItems << item;
  }
 
  if ( !QgsRasterRendererUtils::saveColorMapFile( fileName, colorRampItems, mColorInterpolationComboBox->currentData().value<Qgis::ShaderInterpolationMethod>() ) )
  {
    QMessageBox::warning( this, tr( "Save Color Map as File" ), tr( "Write access denied. Adjust the file permissions and try again.\n\n" ) );
  }
 
  QFileInfo fileInfo( fileName );
  settings.setValue( u"lastColorMapDir"_s, fileInfo.absoluteDir().absolutePath() );
}
 
void QgsColorRampShaderWidget::mUnitLineEdit_textEdited( const QString & )
{
  autoLabel();
 
  if ( !mBlockChanges )
    emit widgetChanged();
}
 
void QgsColorRampShaderWidget::mColormapTreeWidget_itemDoubleClicked( QTreeWidgetItem *item, int column )
{
  if ( !item )
  {
    return;
  }
 
  if ( column == LabelColumn )
  {
    // Set text color to default black, which signifies a manually edited label
    item->setForeground( LabelColumn, QBrush() );
  }
}
 
void QgsColorRampShaderWidget::mColormapTreeWidget_itemEdited( QTreeWidgetItem *item, int column )
{
  Q_UNUSED( item )
 
  switch ( column )
  {
    case ValueColumn:
    {
      autoLabel();
      loadMinimumMaximumFromTree();
      updateColorRamp();
      emit widgetChanged();
      break;
    }
 
    case LabelColumn:
    {
      // call autoLabel to fill when empty or gray out when same as autoLabel
      autoLabel();
      emit widgetChanged();
      break;
    }
 
    case ColorColumn:
    {
      loadMinimumMaximumFromTree();
      updateColorRamp();
      emit widgetChanged();
      break;
    }
  }
}
 
void QgsColorRampShaderWidget::setFromShader( const QgsColorRampShader &colorRampShader )
{
  mBlockChanges++;
 
  // Those objects are connected to classify() the color ramp shader if they change, or call widget change
  // need to block them to avoid to classify and to alter the color ramp, or to call duplicate widget change
  whileBlocking( mClipCheckBox )->setChecked( colorRampShader.clip() );
  whileBlocking( mColorInterpolationComboBox )->setCurrentIndex( mColorInterpolationComboBox->findData( QVariant::fromValue( colorRampShader.colorRampType() ) ) );
  mColorInterpolationComboBox_currentIndexChanged( mColorInterpolationComboBox->currentIndex() );
  whileBlocking( mClassificationModeComboBox )->setCurrentIndex( mClassificationModeComboBox->findData( QVariant::fromValue( colorRampShader.classificationMode() ) ) );
  mClassificationModeComboBox_currentIndexChanged( mClassificationModeComboBox->currentIndex() );
  whileBlocking( mNumberOfEntriesSpinBox )->setValue( colorRampShader.colorRampItemList().count() ); // some default
 
  if ( colorRampShader.sourceColorRamp() )
  {
    whileBlocking( btnColorRamp )->setColorRamp( colorRampShader.sourceColorRamp() );
  }
  else
  {
    QgsSettings settings;
    QString defaultPalette = settings.value( u"/Raster/defaultPalette"_s, "Spectral" ).toString();
    btnColorRamp->setColorRampFromName( defaultPalette );
  }
 
  mLabelPrecisionSpinBox->setValue( colorRampShader.labelPrecision() );
 
  populateColormapTreeWidget( colorRampShader.colorRampItemList() );
 
  if ( colorRampShader.legendSettings() )
    mLegendSettings = *colorRampShader.legendSettings();
 
  mBlockChanges--;
  emit widgetChanged();
}
 
void QgsColorRampShaderWidget::mColorInterpolationComboBox_currentIndexChanged( int index )
{
  Qgis::ShaderInterpolationMethod interpolation = mColorInterpolationComboBox->itemData( index ).value<Qgis::ShaderInterpolationMethod>();
 
  mClipCheckBox->setEnabled( interpolation == Qgis::ShaderInterpolationMethod::Linear );
 
  QString valueLabel;
  QString valueToolTip;
  switch ( interpolation )
  {
    case Qgis::ShaderInterpolationMethod::Linear:
      valueLabel = tr( "Value" );
      valueToolTip = tr( "Value for color stop" );
      mLegendSettingsButton->setEnabled( true );
      break;
    case Qgis::ShaderInterpolationMethod::Discrete:
      valueLabel = tr( "Value <=" );
      valueToolTip = tr( "Maximum value for class" );
      mLegendSettingsButton->setEnabled( false );
      break;
    case Qgis::ShaderInterpolationMethod::Exact:
      valueLabel = tr( "Value =" );
      valueToolTip = tr( "Value for color" );
      mLegendSettingsButton->setEnabled( false );
      break;
  }
 
  QTreeWidgetItem *header = mColormapTreeWidget->headerItem();
  header->setText( ValueColumn, valueLabel );
  header->setToolTip( ValueColumn, valueToolTip );
 
  autoLabel();
  emit widgetChanged();
}
 
void QgsColorRampShaderWidget::setMinimumMaximumAndClassify( double min, double max )
{
  if ( !qgsDoubleNear( mMin, min ) || !qgsDoubleNear( mMax, max ) )
  {
    setMinimumMaximum( min, max );
    classify();
  }
}
 
void QgsColorRampShaderWidget::setMinimumMaximum( double min, double max )
{
  mMin = min;
  mMax = max;
  resetClassifyButton();
}
 
double QgsColorRampShaderWidget::minimum() const
{
  return mMin;
}
 
double QgsColorRampShaderWidget::maximum() const
{
  return mMax;
}
 
bool QgsColorRampShaderWidget::colormapMinMax( double &min, double &max ) const
{
  QTreeWidgetItem *item = mColormapTreeWidget->topLevelItem( 0 );
  if ( !item )
  {
    return false;
  }
 
  // If using discrete, the first and last items contain the upper and lower
  // values of the first and last classes, we don't want these values but real min/max
  if ( !std::isnan( mMin ) && !std::isnan( mMax ) && mColorInterpolationComboBox->currentData().value<Qgis::ShaderInterpolationMethod>() == Qgis::ShaderInterpolationMethod::Discrete )
  {
    min = mMin;
    max = mMax;
  }
  else
  {
    min = item->data( ValueColumn, Qt::ItemDataRole::DisplayRole ).toDouble();
    item = mColormapTreeWidget->topLevelItem( mColormapTreeWidget->topLevelItemCount() - 1 );
    max = item->data( ValueColumn, Qt::ItemDataRole::DisplayRole ).toDouble();
  }
  return true;
}
 
void QgsColorRampShaderWidget::loadMinimumMaximumFromTree()
{
  double min = 0, max = 0;
  if ( !colormapMinMax( min, max ) )
  {
    return;
  }
 
  if ( !qgsDoubleNear( mMin, min ) || !qgsDoubleNear( mMax, max ) )
  {
    mMin = min;
    mMax = max;
    emit minimumMaximumChangedFromTree( min, max );
  }
}
 
void QgsColorRampShaderWidget::resetClassifyButton()
{
  mClassifyButton->setEnabled( true );
  if ( std::isnan( mMin ) || std::isnan( mMax ) || mMin >= mMax )
  {
    mClassifyButton->setEnabled( false );
  }
}
 
QString QgsColorRampShaderWidget::createLabel( QTreeWidgetItem *currentItem, int row, const QString unit )
{
  auto applyPrecision = [this]( const QString &value ) {
    double val { value.toDouble() };
    Qgis::DataType dataType { mRasterDataProvider ? mRasterDataProvider->dataType( mBand ) : Qgis::DataType::Float64 };
    switch ( dataType )
    {
      case Qgis::DataType::Int8:
      case Qgis::DataType::Int16:
      case Qgis::DataType::UInt16:
      case Qgis::DataType::Int32:
      case Qgis::DataType::UInt32:
      case Qgis::DataType::Byte:
      case Qgis::DataType::CInt16:
      case Qgis::DataType::CInt32:
      case Qgis::DataType::ARGB32:
      case Qgis::DataType::ARGB32_Premultiplied:
      {
        return QLocale().toString( std::round( val ), 'f', 0 );
      }
      case Qgis::DataType::Float32:
      case Qgis::DataType::CFloat32:
      {
        if ( mLabelPrecisionSpinBox->value() < 0 )
        {
          const double factor = std::pow( 10, -mLabelPrecisionSpinBox->value() );
          val = static_cast<qlonglong>( val / factor ) * factor;
          return QLocale().toString( val, 'f', 0 );
        }
        return QLocale().toString( val, 'f', mLabelPrecisionSpinBox->value() );
      }
      case Qgis::DataType::Float64:
      case Qgis::DataType::CFloat64:
      case Qgis::DataType::UnknownDataType:
      {
        if ( mLabelPrecisionSpinBox->value() < 0 )
        {
          const double factor = std::pow( 10, -mLabelPrecisionSpinBox->value() );
          val = static_cast<qlonglong>( val / factor ) * factor;
          return QLocale().toString( val, 'f', 0 );
        }
        return QLocale().toString( val, 'f', mLabelPrecisionSpinBox->value() );
      }
    }
    return QString();
  };
 
  Qgis::ShaderInterpolationMethod interpolation = mColorInterpolationComboBox->currentData().value<Qgis::ShaderInterpolationMethod>();
  bool discrete = interpolation == Qgis::ShaderInterpolationMethod::Discrete;
  QString lbl;
 
  if ( discrete )
  {
    if ( row == 0 )
    {
      lbl = "<= " + applyPrecision( currentItem->data( ValueColumn, Qt::ItemDataRole::DisplayRole ).toString() ) + unit;
    }
    else if ( currentItem->data( ValueColumn, Qt::ItemDataRole::DisplayRole ).toDouble() == std::numeric_limits<double>::infinity() )
    {
      lbl = "> " + applyPrecision( mColormapTreeWidget->topLevelItem( row - 1 )->data( ValueColumn, Qt::ItemDataRole::DisplayRole ).toString() ) + unit;
    }
    else
    {
      lbl = applyPrecision( mColormapTreeWidget->topLevelItem( row - 1 )->data( ValueColumn, Qt::ItemDataRole::DisplayRole ).toString() )
            + " - "
            + applyPrecision( currentItem->data( ValueColumn, Qt::ItemDataRole::DisplayRole ).toString() )
            + unit;
    }
  }
  else
  {
    lbl = applyPrecision( currentItem->data( ValueColumn, Qt::ItemDataRole::DisplayRole ).toString() ) + unit;
  }
 
  return lbl;
}
 
void QgsColorRampShaderWidget::changeColor()
{
  QList<QTreeWidgetItem *> itemList;
  itemList = mColormapTreeWidget->selectedItems();
  if ( itemList.isEmpty() )
  {
    return;
  }
  QTreeWidgetItem *firstItem = itemList.first();
 
  QColor currentColor = firstItem->data( ColorColumn, Qt::ItemDataRole::EditRole ).value<QColor>();
  QgsPanelWidget *panel = QgsPanelWidget::findParentPanel( qobject_cast<QWidget *>( parent() ) );
  if ( panel && panel->dockMode() )
  {
    QgsCompoundColorWidget *colorWidget = new QgsCompoundColorWidget( panel, currentColor, QgsCompoundColorWidget::LayoutVertical );
    colorWidget->setPanelTitle( tr( "Select Color" ) );
    colorWidget->setAllowOpacity( true );
    connect( colorWidget, &QgsCompoundColorWidget::currentColorChanged, this, [this, itemList]( const QColor &newColor ) {
      for ( QTreeWidgetItem *item : std::as_const( itemList ) )
      {
        item->setData( ColorColumn, Qt::ItemDataRole::EditRole, newColor );
      }
 
      loadMinimumMaximumFromTree();
      emit widgetChanged();
    } );
    panel->openPanel( colorWidget );
  }
  else
  {
    // modal dialog version... yuck
    QColor newColor = QgsColorDialog::getColor( currentColor, this, u"Change Color"_s, true );
    if ( newColor.isValid() )
    {
      for ( QTreeWidgetItem *item : std::as_const( itemList ) )
      {
        item->setData( ColorColumn, Qt::ItemDataRole::EditRole, newColor );
      }
 
      loadMinimumMaximumFromTree();
      emit widgetChanged();
    }
  }
}
 
void QgsColorRampShaderWidget::changeOpacity()
{
  QList<QTreeWidgetItem *> itemList;
  itemList = mColormapTreeWidget->selectedItems();
  if ( itemList.isEmpty() )
  {
    return;
  }
  QTreeWidgetItem *firstItem = itemList.first();
 
  bool ok;
  double oldOpacity = firstItem->data( ColorColumn, Qt::ItemDataRole::EditRole ).value<QColor>().alpha() / 255 * 100;
  double opacity = QInputDialog::getDouble( this, tr( "Opacity" ), tr( "Change color opacity [%]" ), oldOpacity, 0.0, 100.0, 0, &ok );
  if ( ok )
  {
    int newOpacity = static_cast<int>( opacity / 100 * 255 );
    const auto constItemList = itemList;
    for ( QTreeWidgetItem *item : constItemList )
    {
      QColor newColor = item->data( ColorColumn, Qt::ItemDataRole::EditRole ).value<QColor>();
      newColor.setAlpha( newOpacity );
      item->setData( ColorColumn, Qt::ItemDataRole::EditRole, newColor );
    }
 
    loadMinimumMaximumFromTree();
    emit widgetChanged();
  }
}
 
void QgsColorRampShaderWidget::showLegendSettings()
{
  QgsPanelWidget *panel = QgsPanelWidget::findParentPanel( qobject_cast<QWidget *>( parent() ) );
  if ( panel && panel->dockMode() )
  {
    QgsColorRampLegendNodeWidget *legendPanel = new QgsColorRampLegendNodeWidget();
    legendPanel->setPanelTitle( tr( "Legend Settings" ) );
    legendPanel->setSettings( mLegendSettings );
    connect( legendPanel, &QgsColorRampLegendNodeWidget::widgetChanged, this, [this, legendPanel] {
      mLegendSettings = legendPanel->settings();
      emit widgetChanged();
    } );
    panel->openPanel( legendPanel );
  }
  else
  {
    QgsColorRampLegendNodeDialog dialog( mLegendSettings, this );
    dialog.setWindowTitle( tr( "Legend Settings" ) );
    if ( dialog.exec() )
    {
      mLegendSettings = dialog.settings();
      emit widgetChanged();
    }
  }
}