175 lines
5.2 KiB
C++

// 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"