From ecc16958e69e56a0844967b89937055c4d0f9f23 Mon Sep 17 00:00:00 2001
From: Paddle <PaddleStroke@users.noreply.github.com>
Date: Mon, 14 Aug 2023 08:06:06 +0200
Subject: [PATCH] Core: Stylesheets: Adds support for variables in stylesheets.

---
 src/Gui/Application.cpp | 27 ++++++++++++++++++++++++++-
 src/Gui/Application.h   |  3 ++-
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/src/Gui/Application.cpp b/src/Gui/Application.cpp
index e511f3d35e..188712d585 100644
--- a/src/Gui/Application.cpp
+++ b/src/Gui/Application.cpp
@@ -2480,7 +2480,10 @@ void Application::setStyleSheet(const QString& qssFile, bool tiledBackground)
         if (!f.fileName().isEmpty() && f.open(QFile::ReadOnly | QFile::Text)) {
             mdi->setBackground(QBrush(Qt::NoBrush));
             QTextStream str(&f);
-            qApp->setStyleSheet(str.readAll());
+
+            QString styleSheetContent = replaceVariablesInQss(str.readAll());
+
+            qApp->setStyleSheet(styleSheetContent);
 
             ActionStyleEvent e(ActionStyleEvent::Clear);
             qApp->sendEvent(mw, &e);
@@ -2532,6 +2535,28 @@ void Application::setStyleSheet(const QString& qssFile, bool tiledBackground)
     }
 }
 
+QString Application::replaceVariablesInQss(QString qssText)
+{
+    //First we fetch the colors from preferences,
+    ParameterGrp::handle hGrp = App::GetApplication().GetParameterGroupByPath("User parameter:BaseApp/Preferences/Themes");
+    unsigned long longAccentColor1 = hGrp->GetUnsigned("ThemeAccentColor1", 0);
+    unsigned long longAccentColor2 = hGrp->GetUnsigned("ThemeAccentColor2", 0);
+    unsigned long longAccentColor3 = hGrp->GetUnsigned("ThemeAccentColor3", 0);
+
+    //convert them to hex.
+    //Note: the ulong contains alpha channels so 8 hex characters when we need 6 here.
+    QString accentColor1 = QString::fromLatin1("#%1").arg(longAccentColor1, 8, 16, QLatin1Char('0')).toUpper().mid(0, 7);
+    QString accentColor2 = QString::fromLatin1("#%1").arg(longAccentColor2, 8, 16, QLatin1Char('0')).toUpper().mid(0, 7);
+    QString accentColor3 = QString::fromLatin1("#%1").arg(longAccentColor3, 8, 16, QLatin1Char('0')).toUpper().mid(0, 7);
+
+    qssText = qssText.replace(QString::fromLatin1("@ThemeAccentColor1"), accentColor1);
+    qssText = qssText.replace(QString::fromLatin1("@ThemeAccentColor2"), accentColor2);
+    qssText = qssText.replace(QString::fromLatin1("@ThemeAccentColor3"), accentColor3);
+
+    //Base::Console().Warning("%s\n", qssText.toStdString());
+    return qssText;
+}
+
 void Application::checkForDeprecatedSettings()
 {
     // From 0.21, `FCBak` will be the intended default backup format
diff --git a/src/Gui/Application.h b/src/Gui/Application.h
index bee284c459..f1c6916438 100644
--- a/src/Gui/Application.h
+++ b/src/Gui/Application.h
@@ -209,8 +209,9 @@ public:
 
     /** @name Appearance */
     //@{
-    /// Activate a named workbench
+    /// Activate a stylesheet
     void setStyleSheet(const QString& qssFile, bool tiledBackground);
+    QString replaceVariablesInQss(QString qssText);
     //@}
 
     /** @name User Commands */