libretro-dolphin/Source/Core/DolphinQt/QtUtils/AspectRatioWidget.cpp
2018-07-07 00:48:38 +02:00

46 lines
1.5 KiB
C++

// Copyright 2018 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
// Based on:
// https://stackoverflow.com/questions/30005540/keeping-the-aspect-ratio-of-a-sub-classed-qwidget-during-resize
#include "DolphinQt/QtUtils/AspectRatioWidget.h"
#include <QBoxLayout>
#include <QResizeEvent>
AspectRatioWidget::AspectRatioWidget(QWidget* widget, float width, float height, QWidget* parent)
: QWidget(parent), m_ar_width(width), m_ar_height(height)
{
m_layout = new QBoxLayout(QBoxLayout::LeftToRight, this);
// add spacer, then your widget, then spacer
m_layout->addItem(new QSpacerItem(0, 0));
m_layout->addWidget(widget);
m_layout->addItem(new QSpacerItem(0, 0));
}
void AspectRatioWidget::resizeEvent(QResizeEvent* event)
{
float aspect_ratio = static_cast<float>(event->size().width()) / event->size().height();
int widget_stretch, outer_stretch;
if (aspect_ratio > (m_ar_width / m_ar_height)) // too wide
{
m_layout->setDirection(QBoxLayout::LeftToRight);
widget_stretch = height() * (m_ar_width / m_ar_height); // i.e., my width
outer_stretch = (width() - widget_stretch) / 2 + 0.5;
}
else // too tall
{
m_layout->setDirection(QBoxLayout::TopToBottom);
widget_stretch = width() * (m_ar_height / m_ar_width); // i.e., my height
outer_stretch = (height() - widget_stretch) / 2 + 0.5;
}
m_layout->setStretch(0, outer_stretch);
m_layout->setStretch(1, widget_stretch);
m_layout->setStretch(2, outer_stretch);
}