add: rainbow_style.cpp

Signed-off-by: Collecting <collecting@noreply.localhost>

src/citron/util/rainbow_style.cpp

@@ -0,0 +1,38 @@
+// SPDX-FileCopyrightText: 2025 citron Emulator Project
+
+#include "citron/util/rainbow_style.h"
+#include "citron/uisettings.h"
+#include "citron/theme.h"
+#include <QApplication>
+#include <QPalette>
+#include <QWidget>
+
+float RainbowStyle::s_hue = 0.0f;
+
+RainbowStyle::RainbowStyle(QStyle* baseStyle) : QProxyStyle(baseStyle) {
+    m_timer = new QTimer(this);
+    connect(m_timer, &QTimer::timeout, this, &RainbowStyle::UpdateHue);
+    m_timer->start(33);
+}
+
+void RainbowStyle::UpdateHue() {
+	if (UISettings::values.enable_rainbow_mode.GetValue()) {
+		s_hue += 0.005f;
+		if (s_hue > 1.0f) s_hue = 0.0f;
+	}
+}
+
+QColor RainbowStyle::GetCurrentHighlightColor() {
+    if (!UISettings::values.enable_rainbow_mode.GetValue()) {
+        return QColor(Theme::GetAccentColor());
+    }
+    return QColor::fromHsvF(s_hue, 0.7f, 1.0f);
+}
+
+QPalette RainbowStyle::standardPalette() const {
+    QPalette pal = QProxyStyle::standardPalette();
+    QColor highlight = GetCurrentHighlightColor();
+    pal.setColor(QPalette::Highlight, highlight);
+    pal.setColor(QPalette::Link, highlight);
+    return pal;
+}