ClickableLabel.cpp

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/*
 * Hydrogen
 * Copyright(c) 2002-2008 by Alex >Comix< Cominu [comix@users.sourceforge.net]
 * Copyright(c) 2008-2025 The hydrogen development team [hydrogen-devel@lists.sourceforge.net]
 *
 * http://www.hydrogen-music.org
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY, without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see https://www.gnu.org/licenses
 *
 */
 
#include "ClickableLabel.h"
#include "../HydrogenApp.h"
 
#include <QtGui>
#include <QtWidgets>
 
#include <core/Globals.h>
 
ClickableLabel::ClickableLabel( QWidget *pParent, QSize size, QString sText, Color color, bool bIsEditable )
        : QLabel( pParent )
        , m_size( size )
        , m_color( color )
        , m_bIsEditable( bIsEditable )
        , m_bEntered( false )
{
        if ( ! size.isNull() ) {
                setFixedSize( size );
                resize( size );
        }
        
        auto pPref = H2Core::Preferences::get_instance();
 
        updateFont( pPref->getLevel3FontFamily(), pPref->getFontSize() );
        updateStyleSheet();
 
        setAlignment( Qt::AlignCenter );
        setText( sText );
        
        connect( HydrogenApp::get_instance(), &HydrogenApp::preferencesChanged, this, &ClickableLabel::onPreferencesChanged );
 
}
 
void ClickableLabel::updateStyleSheet() {
 
        auto pPref = H2Core::Preferences::get_instance();
        
        QColor text;
        if ( m_color == Color::Bright ) {
                text = pPref->getColorTheme()->m_windowTextColor;
        } else {
                text = pPref->getColorTheme()->m_widgetTextColor;
        }
 
        setStyleSheet( QString( "QLabel { color: %1; }" ).arg( text.name() ) );
}
 
void ClickableLabel::mousePressEvent( QMouseEvent * e )
{
        UNUSED( e );
        emit labelClicked( this );
}
 
void ClickableLabel::paintEvent( QPaintEvent *ev ) {
 
        QLabel::paintEvent( ev );
 
        if ( ! m_bIsEditable ) {
                return;
        }
 
        auto pPref = H2Core::Preferences::get_instance();
 
        if ( m_bEntered || hasFocus() ) {
                QPainter painter(this);
 
                QColor colorHighlightActive = pPref->getColorTheme()->m_highlightColor;
 
                // If the mouse is placed on the widget but the user hasn't
                // clicked it yet, the highlight will be done more transparent to
                // indicate that keyboard inputs are not accepted yet.
                if ( ! hasFocus() ) {
                        colorHighlightActive.setAlpha( 150 );
                }
 
                QPen pen;
                pen.setColor( colorHighlightActive );
                pen.setWidth( 2 );
                painter.setPen( pen );
                painter.drawRoundedRect( QRect( 1, 1, m_size.width() - 2, m_size.height() - 2 ), 3, 3 );
        }
}
 
#ifdef H2CORE_HAVE_QT6
void ClickableLabel::enterEvent( QEnterEvent *ev ) {
#else
void ClickableLabel::enterEvent( QEvent *ev ) {
#endif
        QLabel::enterEvent( ev );
        if ( m_bIsEditable ) {
                m_bEntered = true;
                update();
        }
}
 
void ClickableLabel::leaveEvent( QEvent* ev ) {
        QLabel::leaveEvent( ev );
        if ( m_bIsEditable ) {
                m_bEntered = false;
                update();
        }
}
 
void ClickableLabel::updateFont( QString sFontFamily, H2Core::FontTheme::FontSize fontSize ) {
 
        int nPixelSize = 0;
        
        if ( ! m_size.isNull() ) {
        
                float fScalingFactor = 1.0;
                switch ( fontSize ) {
                case H2Core::FontTheme::FontSize::Small:
                        fScalingFactor = 1.0;
                        break;
                case H2Core::FontTheme::FontSize::Medium:
                        fScalingFactor = 0.75;
                        break;
                case H2Core::FontTheme::FontSize::Large:
                        fScalingFactor = 0.5;
                        break;
                }
 
                int nMargin;
                if ( m_size.height() <= 9 ) {
                        nMargin = 1;
                } else if ( m_size.height() <= 16 ) {
                        nMargin = 2;
                } else {
                        nMargin = 8;
                }
 
                nPixelSize = m_size.height() - std::round( fScalingFactor * nMargin );
        }
 
        QFont font( sFontFamily );
 
        if ( ! m_size.isNull() ) {
                font.setPixelSize( nPixelSize );
        }
        font.setBold( true );
 
        if ( ! m_size.isNull() || width() > height() ) {
                // Check whether the width of the text fits the available frame
                // width of the label
                while ( QFontMetrics( font ).size( Qt::TextSingleLine, text() ).width() >
                                width() && nPixelSize > 1 ) {
                        nPixelSize--;
                        font.setPixelSize( nPixelSize );
                }
        }
 
        // This method must not be called more than once in this routine. Otherwise,
        // a repaint of the widget is triggered, which calls `updateFont()` again
        // and we are trapped in an infinite loop.
        setFont( font );
}
 
void ClickableLabel::onPreferencesChanged( H2Core::Preferences::Changes changes ) {
        auto pPref = H2Core::Preferences::get_instance();
        
        if ( changes & ( H2Core::Preferences::Changes::Colors |
                                         H2Core::Preferences::Changes::Font ) ) {
                updateFont( pPref->getLevel3FontFamily(), pPref->getFontSize() );
                updateStyleSheet();
        }
}
 
void ClickableLabel::setText( const QString& sNewText ) {
        if ( text() == sNewText ) {
                return;
        }
        
        auto pPref = H2Core::Preferences::get_instance();
        
        QLabel::setText( sNewText );
        updateFont( pPref->getLevel3FontFamily(), pPref->getFontSize() );
}