File indexing completed on 2024-04-28 04:18:54

 // vim: set tabstop=4 shiftwidth=4 expandtab:
 /*
 Gwenview: an image viewer
 Copyright 2008 Aurélien Gâteau <agateau@kde.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, write to the Free Software
 Foundation, Inc., 51 Franklin Street, Fifth Floor, Cambridge, MA 02110-1301, USA.
 
 */
 // Self
 #include "zoomwidget.h"
 
 // stdc++
 #include <cmath>
 
 // Qt
 #include <QAction>
 #include <QActionGroup>
 #include <QHBoxLayout>
 #include <QSlider>
 #include <QToolButton>
 // KF
 
 // Local
 #include "signalblocker.h"
 #include "zoomcombobox/zoomcombobox.h"
 #include "zoomslider.h"
 
 namespace Gwenview
 {
 static const qreal MAGIC_K = 1.04;
 static const qreal MAGIC_OFFSET = 16.;
 static const qreal PRECISION = 100.;
 inline int sliderValueForZoom(qreal zoom)
 {
     return int(PRECISION * (log(zoom) / log(MAGIC_K) + MAGIC_OFFSET));
 }
 
 inline qreal zoomForSliderValue(int sliderValue)
 {
     return pow(MAGIC_K, sliderValue / PRECISION - MAGIC_OFFSET);
 }
 
 struct ZoomWidgetPrivate {
     ZoomWidget *q = nullptr;
 
     QToolButton *mFitButton = nullptr;
     ZoomSlider *mZoomSlider = nullptr;
     ZoomComboBox *mZoomComboBox = nullptr;
     QAction *mActualSizeAction = nullptr;
 
     bool mZoomUpdatedBySlider;
 
     void emitZoomChanged()
     {
         // Use QSlider::sliderPosition(), not QSlider::value() because when we are
         // called from slotZoomSliderActionTriggered(), QSlider::value() has not
         // been updated yet.
         qreal zoom = zoomForSliderValue(mZoomSlider->slider()->sliderPosition());
         mZoomUpdatedBySlider = true;
         Q_EMIT q->zoomChanged(zoom);
         mZoomUpdatedBySlider = false;
     }
 };
 
 ZoomWidget::ZoomWidget(QWidget *parent)
     : QFrame(parent)
     , d(new ZoomWidgetPrivate)
 {
     d->q = this;
     d->mZoomUpdatedBySlider = false;
 
     setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Preferred);
 
     d->mFitButton = new QToolButton(this);
 
     d->mZoomSlider = new ZoomSlider(this);
     d->mZoomSlider->setMinimumWidth(150);
     d->mZoomSlider->slider()->setSingleStep(int(PRECISION));
     d->mZoomSlider->slider()->setPageStep(3 * int(PRECISION));
     connect(d->mZoomSlider->slider(), &QAbstractSlider::actionTriggered, this, &ZoomWidget::slotZoomSliderActionTriggered);
 
     d->mZoomComboBox = new ZoomComboBox(this);
     connect(d->mZoomComboBox, &ZoomComboBox::zoomChanged, this, &ZoomWidget::zoomChanged);
 
     // Layout
     auto layout = new QHBoxLayout(this);
     layout->setContentsMargins(0, 0, 0, 0);
     layout->setSpacing(0);
     layout->addWidget(d->mFitButton);
     layout->addWidget(d->mZoomSlider);
     layout->addWidget(d->mZoomComboBox);
 }
 
 ZoomWidget::~ZoomWidget()
 {
     delete d;
 }
 
 void ZoomWidget::setActions(QAction *zoomToFitAction, QAction *actualSizeAction, QAction *zoomInAction, QAction *zoomOutAction, QAction *zoomToFillAction)
 {
     d->mFitButton->setDefaultAction(zoomToFitAction);
     d->mFitButton->setToolButtonStyle(Qt::ToolButtonStyle::ToolButtonTextOnly);
 
     d->mZoomSlider->setZoomInAction(zoomInAction);
     d->mZoomSlider->setZoomOutAction(zoomOutAction);
 
     d->mZoomComboBox->setActions(zoomToFitAction, zoomToFillAction, actualSizeAction);
 
     auto actionGroup = new QActionGroup(d->q);
     actionGroup->addAction(zoomToFitAction);
     actionGroup->addAction(zoomToFillAction);
     actionGroup->addAction(actualSizeAction);
     actionGroup->setExclusionPolicy(QActionGroup::ExclusionPolicy::ExclusiveOptional);
 
     d->mActualSizeAction = actualSizeAction;
 }
 
 void ZoomWidget::slotZoomSliderActionTriggered()
 {
     // The slider value changed because of the user (not because of range
     // changes). In this case disable zoom and apply slider value.
     d->emitZoomChanged();
 }
 
 void ZoomWidget::setZoom(qreal zoom)
 {
     if (zoom != 1.0) {
         d->mActualSizeAction->setChecked(false);
     }
     d->mZoomComboBox->setValue(zoom);
 
     // Don't change slider value if we come here because the slider change,
     // avoids choppy sliding scroll.
     if (!d->mZoomUpdatedBySlider) {
         QSlider *slider = d->mZoomSlider->slider();
         SignalBlocker blocker(slider);
         int value = sliderValueForZoom(zoom);
 
         if (value < slider->minimum()) {
             // It is possible that we are called *before* setMinimumZoom() as
             // been called. In this case, define the minimum ourself.
             d->mZoomSlider->setMinimum(value);
         }
         d->mZoomSlider->setValue(value);
     }
 }
 
 void ZoomWidget::setMinimumZoom(qreal minimumZoom)
 {
     d->mZoomSlider->setMinimum(sliderValueForZoom(minimumZoom));
     d->mZoomComboBox->setMinimum(minimumZoom);
 }
 
 void ZoomWidget::setMaximumZoom(qreal zoom)
 {
     d->mZoomSlider->setMaximum(sliderValueForZoom(zoom));
     d->mZoomComboBox->setMaximum(zoom);
 }
 
 } // namespace
 
 #include "moc_zoomwidget.cpp"