Qt: Fix DPI icon scaling in various settings windows

pcsx2-qt/CoverDownloadDialog.cpp

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: GPL-3.0+
 
 #include "CoverDownloadDialog.h"
+#include "QtUtils.h"
 
 #include "pcsx2/GameList.h"
 
@@ -11,7 +12,7 @@ CoverDownloadDialog::CoverDownloadDialog(QWidget* parent /*= nullptr*/)
 	: QDialog(parent)
 {
 	m_ui.setupUi(this);
-	m_ui.coverIcon->setPixmap(QIcon::fromTheme("artboard-2-line").pixmap(32));
+	QtUtils::SetScalableIcon(m_ui.coverIcon, QIcon::fromTheme(QStringLiteral("artboard-2-line")), QSize(32, 32));
 	updateEnabled();
 
 	connect(m_ui.start, &QPushButton::clicked, this, &CoverDownloadDialog::onStartClicked);

pcsx2-qt/QtUtils.cpp

@@ -374,4 +374,37 @@ namespace QtUtils
 
 		return true;
 	}
+
+	class IconVariableDpiFilter : QObject
+	{
+	public:
+		explicit IconVariableDpiFilter(QLabel* lbl, const QIcon& icon, const QSize& size, QObject* parent = nullptr)
+			: QObject(parent)
+			, m_lbl{lbl}
+			, m_icn{icon}
+			, m_size{size}
+		{
+			lbl->installEventFilter(this);
+			m_lbl->setPixmap(m_icn.pixmap(m_size, m_lbl->devicePixelRatioF()));
+		}
+
+	protected:
+		bool eventFilter(QObject* object, QEvent* event) override
+		{
+			if (object == m_lbl && event->type() == QEvent::DevicePixelRatioChange)
+				m_lbl->setPixmap(m_icn.pixmap(m_size, m_lbl->devicePixelRatioF()));
+			// Don't block the event
+			return false;
+		}
+
+	private:
+		QLabel* m_lbl;
+		QIcon m_icn;
+		QSize m_size;
+	};
+
+	void SetScalableIcon(QLabel* lbl, const QIcon& icon, const QSize& size)
+	{
+		new IconVariableDpiFilter(lbl, icon, size, lbl);
+	}
 } // namespace QtUtils

pcsx2-qt/QtUtils.h

@@ -20,6 +20,7 @@ class QAction;
 class QComboBox;
 class QFileInfo;
 class QFrame;
+class QIcon;
 class QLabel;
 class QKeyEvent;
 class QSlider;
@@ -102,4 +103,8 @@ namespace QtUtils
 	bool IsLightTheme(const QPalette& palette);
 
 	bool IsCompositorManagerRunning();
+
+	/// Sets the scalable icon to a given label (svg icons, or icons with multiple size pixmaps)
+	/// The icon will then be reloaded on DPR changes using an event filter
+	void SetScalableIcon(QLabel* lbl, const QIcon& icon, const QSize& size);
 } // namespace QtUtils

pcsx2-qt/Settings/AchievementLoginDialog.cpp

@@ -3,6 +3,7 @@
 
 #include "AchievementLoginDialog.h"
 #include "QtHost.h"
+#include "QtUtils.h"
 
 #include "pcsx2/Achievements.h"
 
@@ -15,7 +16,7 @@ AchievementLoginDialog::AchievementLoginDialog(QWidget* parent, Achievements::Lo
 	, m_reason(reason)
 {
 	m_ui.setupUi(this);
-	m_ui.loginIcon->setPixmap(QIcon::fromTheme("login-box-line").pixmap(32));
+	QtUtils::SetScalableIcon(m_ui.loginIcon, QIcon::fromTheme(QStringLiteral("login-box-line")), QSize(32, 32));
 	setWindowFlags(windowFlags() & ~Qt::WindowContextHelpButtonHint);
 
 	// Adjust text if needed based on reason.
@@ -116,7 +117,6 @@ void AchievementLoginDialog::processLoginResult(bool result, const QString& mess
 				g_emu_thread->resetVM();
 			}
 		}
-
 	}
 
 	done(0);

pcsx2-qt/Settings/AudioSettingsWidget.cpp

@@ -342,7 +342,7 @@ void AudioSettingsWidget::onExpansionSettingsClicked()
 	QDialog dlg(QtUtils::GetRootWidget(this));
 	Ui::AudioExpansionSettingsDialog dlgui;
 	dlgui.setupUi(&dlg);
-	dlgui.icon->setPixmap(QIcon::fromTheme(QStringLiteral("volume-up-line")).pixmap(32, 32));
+	QtUtils::SetScalableIcon(dlgui.icon, QIcon::fromTheme(QStringLiteral("volume-up-line")), QSize(32, 32));
 
 	SettingsInterface* sif = m_dialog->getSettingsInterface();
 	SettingWidgetBinder::BindWidgetToIntSetting(sif, dlgui.blockSize, "SPU2/Output", "ExpandBlockSize",
@@ -431,7 +431,7 @@ void AudioSettingsWidget::onStretchSettingsClicked()
 	QDialog dlg(QtUtils::GetRootWidget(this));
 	Ui::AudioStretchSettingsDialog dlgui;
 	dlgui.setupUi(&dlg);
-	dlgui.icon->setPixmap(QIcon::fromTheme(QStringLiteral("volume-up-line")).pixmap(32, 32));
+	QtUtils::SetScalableIcon(dlgui.icon, QIcon::fromTheme(QStringLiteral("volume-up-line")), QSize(32, 32));
 
 	SettingsInterface* sif = m_dialog->getSettingsInterface();
 	SettingWidgetBinder::BindWidgetToIntSetting(sif, dlgui.sequenceLength, "SPU2/Output", "StretchSequenceLengthMS",

pcsx2-qt/Settings/ControllerGlobalSettingsWidget.cpp

@@ -170,7 +170,7 @@ ControllerMouseSettingsDialog::ControllerMouseSettingsDialog(QWidget* parent, Co
 
 	SettingsInterface* sif = dialog->getProfileSettingsInterface();
 
-	m_ui.icon->setPixmap(QIcon::fromTheme(QStringLiteral("mouse-line")).pixmap(32, 32));
+	QtUtils::SetScalableIcon(m_ui.icon, QIcon::fromTheme(QStringLiteral("mouse-line")), QSize(32, 32));
 
 	ControllerSettingWidgetBinder::BindWidgetToInputProfileFloat(sif, m_ui.pointerXSpeedSlider, "Pad", "PointerXSpeed", 40.0f);
 	ControllerSettingWidgetBinder::BindWidgetToInputProfileFloat(sif, m_ui.pointerYSpeedSlider, "Pad", "PointerYSpeed", 40.0f);
@@ -202,11 +202,10 @@ ControllerMappingSettingsDialog::ControllerMappingSettingsDialog(ControllerSetti
 
 	SettingsInterface* sif = parent->getProfileSettingsInterface();
 
-	m_ui.icon->setPixmap(QIcon::fromTheme(QStringLiteral("settings-3-line")).pixmap(32, 32));
+	QtUtils::SetScalableIcon(m_ui.icon, QIcon::fromTheme(QStringLiteral("settings-3-line")), QSize(32, 32));
 
 	ControllerSettingWidgetBinder::BindWidgetToInputProfileBool(sif, m_ui.ignoreInversion, "InputSources", "IgnoreInversion", false);
 
 	connect(m_ui.buttonBox->button(QDialogButtonBox::Close), &QPushButton::clicked, this, &QDialog::accept);
 }
-
 ControllerMappingSettingsDialog::~ControllerMappingSettingsDialog() = default;

pcsx2-qt/Settings/MemoryCardCreateDialog.cpp

@@ -9,6 +9,7 @@
 #include <QtWidgets/QPushButton>
 
 #include "Settings/MemoryCardCreateDialog.h"
+#include "QtUtils.h"
 
 #include "pcsx2/SIO/Memcard/MemoryCardFile.h"
 
@@ -16,7 +17,7 @@ MemoryCardCreateDialog::MemoryCardCreateDialog(QWidget* parent /* = nullptr */)
 	: QDialog(parent)
 {
 	m_ui.setupUi(this);
-	m_ui.icon->setPixmap(QIcon::fromTheme("memcard-line").pixmap(m_ui.icon->width()));
+	QtUtils::SetScalableIcon(m_ui.icon, QIcon::fromTheme(QStringLiteral("memcard-line")), QSize(m_ui.icon->width(), m_ui.icon->width()));
 
 	setWindowFlags(windowFlags() & ~Qt::WindowContextHelpButtonHint);