From d99ef327a885874fed1c4e35e0f47b10290c6bd9 Mon Sep 17 00:00:00 2001
From: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>
Date: Thu, 8 Apr 2021 14:27:14 +0300
Subject: [PATCH] qt: Add GUIUtil::ThemedLabel class

The ThemedLabel class correctly handles appearance changes on macOS.
---
 src/qt/guiutil.cpp | 31 +++++++++++++++++++++++++++++++
 src/qt/guiutil.h   | 20 ++++++++++++++++++++
 2 files changed, 51 insertions(+)

diff --git a/src/qt/guiutil.cpp b/src/qt/guiutil.cpp
index d10bf9f9aeb..3c4f3df89d0 100644
--- a/src/qt/guiutil.cpp
+++ b/src/qt/guiutil.cpp
@@ -6,6 +6,7 @@
 
 #include <qt/bitcoinaddressvalidator.h>
 #include <qt/bitcoinunits.h>
+#include <qt/platformstyle.h>
 #include <qt/qvalidatedlineedit.h>
 #include <qt/sendcoinsrecipient.h>
 
@@ -61,6 +62,7 @@
 #include <QUrlQuery>
 #include <QtGlobal>
 
+#include <cassert>
 #include <chrono>
 
 #if defined(Q_OS_MAC)
@@ -786,6 +788,35 @@ qreal calculateIdealFontSize(int width, const QString& text, QFont font, qreal m
     return font_size;
 }
 
+ThemedLabel::ThemedLabel(const PlatformStyle* platform_style, QWidget* parent)
+    : QLabel{parent}, m_platform_style{platform_style}
+{
+    assert(m_platform_style);
+}
+
+void ThemedLabel::setThemedPixmap(const QString& image_filename, int width, int height)
+{
+    m_image_filename = image_filename;
+    m_pixmap_width = width;
+    m_pixmap_height = height;
+    updateThemedPixmap();
+}
+
+void ThemedLabel::changeEvent(QEvent* e)
+{
+#ifdef Q_OS_MACOS
+    if (e->type() == QEvent::PaletteChange) {
+        updateThemedPixmap();
+    }
+#endif
+    QLabel::changeEvent(e);
+}
+
+void ThemedLabel::updateThemedPixmap()
+{
+    setPixmap(m_platform_style->SingleColorIcon(m_image_filename).pixmap(m_pixmap_width, m_pixmap_height));
+}
+
 void ClickableLabel::mouseReleaseEvent(QMouseEvent *event)
 {
     Q_EMIT clicked(event->pos());
diff --git a/src/qt/guiutil.h b/src/qt/guiutil.h
index a1cf2743549..31e7aa73355 100644
--- a/src/qt/guiutil.h
+++ b/src/qt/guiutil.h
@@ -27,6 +27,7 @@
 #include <chrono>
 #include <utility>
 
+class PlatformStyle;
 class QValidatedLineEdit;
 class SendCoinsRecipient;
 
@@ -221,6 +222,25 @@ namespace GUIUtil
 
     qreal calculateIdealFontSize(int width, const QString& text, QFont font, qreal minPointSize = 4, qreal startPointSize = 14);
 
+    class ThemedLabel : public QLabel
+    {
+        Q_OBJECT
+
+    public:
+        explicit ThemedLabel(const PlatformStyle* platform_style, QWidget* parent = nullptr);
+        void setThemedPixmap(const QString& image_filename, int width, int height);
+
+    protected:
+        void changeEvent(QEvent* e) override;
+
+    private:
+        const PlatformStyle* m_platform_style;
+        QString m_image_filename;
+        int m_pixmap_width;
+        int m_pixmap_height;
+        void updateThemedPixmap();
+    };
+
     class ClickableLabel : public QLabel
     {
         Q_OBJECT