Files
oak-editor/app/widget/viewer/viewersizer.cpp
T
itsmattkc c1c8067ee7 viewer: implemented basic zoom
No scrolling functionality yet, but the zoom is functional and efficient.
2020-03-13 16:41:09 +11:00

117 lines
2.5 KiB
C++

#include "viewersizer.h"
#include <QMatrix4x4>
ViewerSizer::ViewerSizer(QWidget *parent) :
QWidget(parent),
widget_(nullptr),
aspect_ratio_(0),
zoom_(0)
{
}
void ViewerSizer::SetWidget(QWidget *widget)
{
// Delete any previous widgets occupying this space
delete widget_;
widget_ = widget;
if (widget_ != nullptr) {
widget_->setParent(this);
UpdateSize();
}
}
void ViewerSizer::SetChildSize(int width, int height)
{
width_ = width;
height_ = height;
if (!width_ || !height_) {
aspect_ratio_ = 0;
} else {
aspect_ratio_ = static_cast<double>(width_) / static_cast<double>(height_);
}
UpdateSize();
}
void ViewerSizer::SetZoom(int percent)
{
zoom_ = percent;
UpdateSize();
}
void ViewerSizer::resizeEvent(QResizeEvent *event)
{
QWidget::resizeEvent(event);
UpdateSize();
}
void ViewerSizer::UpdateSize()
{
if (widget_ == nullptr) {
return;
}
// If the aspect ratio is 0, the widget is always hidden
if (qIsNull(aspect_ratio_)) {
widget_->setVisible(false);
return;
}
widget_->setVisible(true);
QSize child_size;
QMatrix4x4 child_matrix;
if (zoom_ <= 0) {
// If zoom is 0, we auto-fit
double our_aspect_ratio = static_cast<double>(width()) / static_cast<double>(height());
child_size = size();
if (our_aspect_ratio > aspect_ratio_) {
// This container is wider than the image, scale by height
child_size = QSize(qRound(child_size.height() * aspect_ratio_), height());
} else {
// This container is taller than the image, scale by width
child_size = QSize(width(), qRound(child_size.width() / aspect_ratio_));
}
} else {
float x_scale = 1.0f;
float y_scale = 1.0f;
int zoomed_width = qRound(width_ * static_cast<double>(zoom_) * 0.01);
int zoomed_height = qRound(height_ * static_cast<double>(zoom_) * 0.01);
if (zoomed_width > width()) {
x_scale = static_cast<double>(zoomed_width) / static_cast<double>(width());
zoomed_width = width();
}
if (zoomed_height > height()) {
y_scale = static_cast<double>(zoomed_height) / static_cast<double>(height());
zoomed_height = height();
}
// Rather than make a huge surface, we still crop at our width/height and then signal a matrix
child_matrix.scale(x_scale, y_scale, 1.0F);
child_size = QSize(zoomed_width, zoomed_height);
}
widget_->resize(child_size);
widget_->move(width() / 2 - child_size.width() / 2, height() / 2 - child_size.height() / 2);
emit RequestMatrix(child_matrix);
}