Merge bitcoin-core/gui#275: Support runtime appearance adjustment on macOS

c231254a65d390a3350fcef456d57e4a6eca0506 qt: Make TransactionView aware of runtime palette change (Hennadii Stepanov)
2b622d4aced1848393989ee906b1f9d2436f1c1a qt: Make CoinControlDialog aware of runtime palette change (Hennadii Stepanov)
97a6b5e06a532a4ee029c8ba59c3438369f8b049 qt: Make OverviewPage aware of runtime palette change (Hennadii Stepanov)
d05f1b278d9846de5142a4ac3f53c84145330dd1 qt: Make UnitDisplayStatusBarControl aware of runtime palette change (Hennadii Stepanov)
6b2ce65392dc98250e84941370e975048b8afc54 qt: Replace base class of ClickableLabel with ThemedLabel (Hennadii Stepanov)
ff530a2093c294a1093e1b00fb66ab0a98851c04 qt: Use GUIUtil::ThemedLabel class (Hennadii Stepanov)
d99ef327a885874fed1c4e35e0f47b10290c6bd9 qt: Add GUIUtil::ThemedLabel class (Hennadii Stepanov)
c054720e08b5549913f54b9b4bc4e4002617ff23 qt: Make SignVerifyMessageDialog aware of runtime palette change (Hennadii Stepanov)
0dcc3fac433b341eb6e1d3a2fb4d2de1595e8e88 qt: Make SendCoinsEntry aware of runtime palette change (Hennadii Stepanov)
fa18d28e1242c2948814df1082ee12c2fecf5403 qt: Make RPCConsole aware of runtime palette change (Hennadii Stepanov)
f1083826e3e68803da86af6efba21c4080769b5c qt: Make BitcoinGUI aware of runtime palette change (Hennadii Stepanov)
ce17861dc419b0d1fc1d933000f484dd08bacf5b qt: Make PlatformStyle aware of runtime palette change (Hennadii Stepanov)

Pull request description:

  On macOS switching appearance (Light -> Dark or Dark -> Light) when Bitcoin Core is running makes the GUI pretty unusable.
  This bug is especially important when a user chose the "Auto" mode to adjust appearance automatically.

  This PR fixes Bitcoin Core behavior.

  This is an alternative to #268.

ACKs for top commit:
  Sjors:
    tACK c231254a65d390a3350fcef456d57e4a6eca0506 on macOS 11.4
  goums:
    ACK c231254a65d390a3350fcef456d57e4a6eca0506
  promag:
    Tested ACK c231254a65d390a3350fcef456d57e4a6eca0506 on macOS Big Sur arm64.
  jarolrod:
    tACK c231254a65d390a3350fcef456d57e4a6eca0506

Tree-SHA512: 122dda3e4c9703f68cec60613c536ca59d04c93f2c03398559f2361b8d279ae534800e8e677d94a33e10e769d00be54295a704e98afa2e986a06146b9f164854

1 files changed, 36 insertions, 0 deletions

diff --git a/src/qt/guiutil.cpp b/src/qt/guiutil.cpp
index 55e57d425d..5ff40ae924 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)
@@ -791,6 +793,40 @@ 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));
+}
+
+ClickableLabel::ClickableLabel(const PlatformStyle* platform_style, QWidget* parent)
+    : ThemedLabel{platform_style, parent}
+{
+}
+
 void ClickableLabel::mouseReleaseEvent(QMouseEvent *event)
 {
     Q_EMIT clicked(event->pos());