From da639c816a100d9a10244d554630a23784db121e Mon Sep 17 00:00:00 2001
From: Martchus <martchus@gmx.net>
Date: Wed, 15 Sep 2021 19:56:09 +0200
Subject: [PATCH] Deduce default color from current palette or style

---
 iconengineplugin/CMakeLists.txt | 10 ++++++
 iconengineplugin/iconengine.cpp | 58 ++++++++++++++++++++++++++++-----
 2 files changed, 59 insertions(+), 9 deletions(-)

diff --git a/iconengineplugin/CMakeLists.txt b/iconengineplugin/CMakeLists.txt
index 108e098..bb484f7 100644
--- a/iconengineplugin/CMakeLists.txt
+++ b/iconengineplugin/CMakeLists.txt
@@ -17,6 +17,16 @@ use_qt_utilities(ONLY_HEADERS VISIBILITY PRIVATE)
 find_package(qtforkawesome${CONFIGURATION_PACKAGE_SUFFIX_QTFORKAWESOME} ${META_APP_VERSION} REQUIRED)
 use_qt_fork_awesome()
 
+# use Qt Gui module
+list(APPEND ADDITIONAL_QT_MODULES Gui)
+
+# configure styling support
+option(ENABLE_STYLE_SUPPORT "whether to apply icon mode via QStyle (pulls in Qt Widgets dependency)" OFF)
+if (ENABLE_STYLE_SUPPORT)
+    list(APPEND ADDITIONAL_QT_MODULES Widgets)
+    set(META_CUSTOM_CONFIG "#define ${META_PROJECT_VARNAME}_ENABLE_STYLE_SUPPORT 1\n")
+endif ()
+
 include(BasicConfig)
 include(QtGuiConfig)
 include(QtConfig)
diff --git a/iconengineplugin/iconengine.cpp b/iconengineplugin/iconengine.cpp
index d093a6f..fa5c180 100644
--- a/iconengineplugin/iconengine.cpp
+++ b/iconengineplugin/iconengine.cpp
@@ -3,18 +3,26 @@
 #include "../qtforkawesome/renderer.h"
 #include "../qtforkawesome/utils.h"
 
+#include "resources/config.h"
+
 #include <qtutilities/misc/compat.h>
 
-#include <QCoreApplication>
+#include <QGuiApplication>
 #include <QPainter>
 #include <QString>
+#include <QPalette>
+#ifdef QT_FORK_AWESOME_ICON_ENGINE_ENABLE_STYLE_SUPPORT
+#include <QApplication>
+#include <QStyle>
+#include <QStyleOption>
+#endif
 
 namespace QtForkAwesome {
 
 IconEngine::IconEngine(Renderer &renderer)
     : m_renderer(renderer)
     , m_char(0)
-    , m_color(Qt::black)
+    , m_color()
 {
 }
 
@@ -22,7 +30,7 @@ IconEngine::IconEngine(const IconEngine &other)
     : QIconEngine(other)
     , m_renderer(other.m_renderer)
     , m_char(0)
-    , m_color(Qt::black)
+    , m_color()
 {
 }
 
@@ -32,16 +40,48 @@ IconEngine::~IconEngine()
 
 QPixmap IconEngine::pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state)
 {
-    Q_UNUSED(mode)
     Q_UNUSED(state)
-    return m_renderer.pixmap(QChar(m_char), size, m_color);
+
+    auto color = m_color;
+    if (!m_color.isValid()) {
+        auto group = QPalette::Normal;
+        auto role = QPalette::Text;
+#ifndef QT_FORK_AWESOME_ICON_ENGINE_ENABLE_STYLE_SUPPORT
+        switch (mode) {
+        case QIcon::Disabled:
+            group = QPalette::Disabled;
+            break;
+        case QIcon::Active:
+            group = QPalette::Active;
+            break;
+        case QIcon::Selected:
+            role = QPalette::HighlightedText;
+            break;
+        default:
+            ;
+        }
+#endif
+        color = QGuiApplication::palette().color(group, role);
+    }
+
+    auto pixmap = m_renderer.pixmap(QChar(m_char), size, color);
+#ifdef QT_FORK_AWESOME_ICON_ENGINE_ENABLE_STYLE_SUPPORT
+    auto *const app = qobject_cast<QApplication *>(QApplication::instance());
+    if (auto *const style = app ? app->style() : nullptr) {
+        auto opt = QStyleOption();
+        opt.palette = QGuiApplication::palette();
+        if (const auto generated = style->generatedIconPixmap(mode, pixmap, &opt); !generated.isNull()) {
+            pixmap = generated;
+        }
+    }
+#endif
+
+    return pixmap;
 }
 
 void IconEngine::paint(QPainter *painter, const QRect &rect, QIcon::Mode mode, QIcon::State state)
 {
-    Q_UNUSED(mode)
-    Q_UNUSED(state)
-    m_renderer.render(QChar(m_char), painter, rect, m_color);
+    painter->drawPixmap(rect, pixmap(rect.size(), mode, state));
 }
 
 void IconEngine::addFile(const QString &fileName, const QSize &, QIcon::Mode mode, QIcon::State state)
@@ -56,7 +96,7 @@ void IconEngine::addFile(const QString &fileName, const QSize &, QIcon::Mode mod
         return;
     }
     m_char = static_cast<IconBaseType>(iconFromId(parts.at(0).toString()));
-    m_color = parts.size() > 1 ? QColor(parts.at(1)) : Qt::black;
+    m_color = parts.size() > 1 ? QColor(parts.at(1)) : QColor();
 }
 
 QString IconEngine::key() const