From f9c36d0a999c1b16c40594c23fc8da04541475d6 Mon Sep 17 00:00:00 2001
From: Klaus Basan <klaus.basan@klausbasan.de>
Date: Wed, 13 Jul 2016 18:33:58 +0200
Subject: [PATCH] Improved automatic reloading of altered stylesheets

---
 src/blackgui/stylesheetutility.cpp | 20 +++++++++++++++-----
 src/blackgui/stylesheetutility.h   |  5 +++--
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/src/blackgui/stylesheetutility.cpp b/src/blackgui/stylesheetutility.cpp
index ba6ac6a9c..234f0c548 100644
--- a/src/blackgui/stylesheetutility.cpp
+++ b/src/blackgui/stylesheetutility.cpp
@@ -36,8 +36,8 @@ namespace BlackGui
     CStyleSheetUtility::CStyleSheetUtility(BlackMisc::Restricted<CGuiApplication>, QObject *parent) : QObject(parent)
     {
         this->read();
-        this->m_fileWatcher.addPath(CBuildConfig::getStylesheetsDir());
         connect(&this->m_fileWatcher, &QFileSystemWatcher::directoryChanged, this, &CStyleSheetUtility::ps_qssDirectoryChanged);
+        connect(&this->m_fileWatcher, &QFileSystemWatcher::fileChanged, this, &CStyleSheetUtility::ps_qssDirectoryChanged);
     }
 
     const QString &CStyleSheetUtility::fontStyleAsString(const QFont &font)
@@ -113,26 +113,36 @@ namespace BlackGui
         if (!directory.exists()) { return false; }
 
         // qss/css files
+        const bool needsWatcher = this->m_fileWatcher.files().isEmpty();
+        if (needsWatcher) { this->m_fileWatcher.addPath(CBuildConfig::getStylesheetsDir()); } // directory to deleted file watching
         directory.setNameFilters({"*.qss", "*.css"});
         directory.setFilter(QDir::Files | QDir::Hidden | QDir::NoSymLinks);
 
-        this->m_styleSheets.clear();
+        QMap<QString, QString> newStyleSheets;
         const QFileInfoList fileInfoList = directory.entryInfoList();
         for (const QFileInfo &fileInfo : fileInfoList)
         {
-            QFile file(fileInfo.absoluteFilePath());
+            const QString absolutePath = fileInfo.absoluteFilePath();
+            QFile file(absolutePath);
             if (file.open(QFile::QIODevice::ReadOnly | QIODevice::Text))
             {
+                if (needsWatcher) { this->m_fileWatcher.addPath(absolutePath); }
                 QTextStream in(&file);
                 const QString c = in.readAll();
                 const QString f = fileInfo.fileName().toLower();
 
                 // keep even empty files as placeholders
-                this->m_styleSheets.insert(f, c);
+                newStyleSheets.insert(f, c);
             }
             file.close();
         }
-        emit this->styleSheetsChanged();
+
+        // ignore redundant re-reads
+        if (newStyleSheets != this->m_styleSheets)
+        {
+            this->m_styleSheets = newStyleSheets;
+            emit this->styleSheetsChanged();
+        }
         return true;
     }
 
diff --git a/src/blackgui/stylesheetutility.h b/src/blackgui/stylesheetutility.h
index f0695bd15..5457710c1 100644
--- a/src/blackgui/stylesheetutility.h
+++ b/src/blackgui/stylesheetutility.h
@@ -14,6 +14,7 @@
 
 #include "blackgui/blackguiexport.h"
 #include "blackmisc/restricted.h"
+#include "blackmisc/digestsignal.h"
 
 #include <QFileSystemWatcher>
 #include <QMap>
@@ -144,8 +145,8 @@ namespace BlackGui
         void ps_qssDirectoryChanged(const QString &file);
 
     private:
-        QMap<QString, QString>    m_styleSheets;         //!< filename, stylesheet
-        QFileSystemWatcher        m_fileWatcher {this};  //!< Monitor my qss files
+        QMap<QString, QString>   m_styleSheets;         //!< filename, stylesheet
+        QFileSystemWatcher       m_fileWatcher {this};  //!< Monitor my qss files
     };
 }
 #endif // guard