From 91f14e0146f82a39ee8f9675e4878596c36fd21c Mon Sep 17 00:00:00 2001
From: Alberto Griggio <agriggio@users.noreply.github.com>
Date: Fri, 9 Feb 2018 22:20:55 +0100
Subject: [PATCH] added option 'InspectorDelay' to delay generation of
 inspector previews

---
 rtgui/inspector.cc | 20 +++++++++++++++++++-
 rtgui/inspector.h  |  5 +++++
 rtgui/options.cc   |  6 ++++++
 rtgui/options.h    |  1 +
 4 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/rtgui/inspector.cc b/rtgui/inspector.cc
index 4084e300f..6da62cd3b 100644
--- a/rtgui/inspector.cc
+++ b/rtgui/inspector.cc
@@ -210,6 +210,23 @@ void Inspector::switchImage (const Glib::ustring &fullPath)
         return;
     }
 
+    if (delayconn.connected()) {
+        delayconn.disconnect();
+    }
+
+    next_image_path = fullPath;
+    if (!options.inspectorDelay) {
+        doSwitchImage();
+    } else {
+        delayconn = Glib::signal_timeout().connect(sigc::mem_fun(*this, &Inspector::doSwitchImage), options.inspectorDelay);
+    }
+}
+
+
+bool Inspector::doSwitchImage()
+{
+    Glib::ustring fullPath = next_image_path;
+    
     // we first check the size of the list, it may have been changed in Preference
     if (images.size() > size_t(options.maxInspectorBuffers)) {
         // deleting the last entries
@@ -225,7 +242,6 @@ void Inspector::switchImage (const Glib::ustring &fullPath)
     if (fullPath.empty()) {
         currImage = nullptr;
         queue_draw();
-        return;
     } else {
         bool found = false;
 
@@ -264,6 +280,8 @@ void Inspector::switchImage (const Glib::ustring &fullPath)
             }
         }
     }
+
+    return true;
 }
 
 void Inspector::deleteBuffers ()
diff --git a/rtgui/inspector.h b/rtgui/inspector.h
index f68912dc1..ac8f52ee2 100644
--- a/rtgui/inspector.h
+++ b/rtgui/inspector.h
@@ -48,9 +48,14 @@ private:
     double zoom;
     bool active;
 
+    sigc::connection delayconn;
+    Glib::ustring next_image_path;
+
     bool on_draw(const ::Cairo::RefPtr< Cairo::Context> &cr);
     void deleteBuffers();
 
+    bool doSwitchImage();
+
 public:
     Inspector();
     ~Inspector();
diff --git a/rtgui/options.cc b/rtgui/options.cc
index dda61419f..2e8d20f96 100644
--- a/rtgui/options.cc
+++ b/rtgui/options.cc
@@ -426,6 +426,7 @@ void Options::setDefaults ()
 #endif
     filledProfile = false;
     maxInspectorBuffers = 2; //  a rather conservative value for low specced systems...
+    inspectorDelay = 0;
     serializeTiffRead = true;
 
     FileBrowserToolbarSingleRow = false;
@@ -1056,6 +1057,10 @@ void Options::readFromFile (Glib::ustring fname)
                     maxInspectorBuffers = keyFile.get_integer ("Performance", "MaxInspectorBuffers");
                 }
 
+                if (keyFile.has_key ("Performance", "InspectorDelay")) {
+                    inspectorDelay = keyFile.get_integer("Performance", "InspectorDelay");
+                }
+
                 if (keyFile.has_key ("Performance", "PreviewDemosaicFromSidecar")) {
                     prevdemo = (prevdemo_t)keyFile.get_integer ("Performance", "PreviewDemosaicFromSidecar");
                 }
@@ -1847,6 +1852,7 @@ void Options::saveToFile (Glib::ustring fname)
         keyFile.set_integer ("Performance", "SIMPLNRAUT", rtSettings.leveldnautsimpl);
         keyFile.set_integer ("Performance", "ClutCacheSize", clutCacheSize);
         keyFile.set_integer ("Performance", "MaxInspectorBuffers", maxInspectorBuffers);
+        keyFile.set_integer ("Performance", "InspectorDelay", inspectorDelay);
         keyFile.set_integer ("Performance", "PreviewDemosaicFromSidecar", prevdemo);
         keyFile.set_boolean ("Performance", "Daubechies", rtSettings.daubech);
         keyFile.set_boolean ("Performance", "SerializeTiffRead", serializeTiffRead);
diff --git a/rtgui/options.h b/rtgui/options.h
index a5eef1543..920968956 100644
--- a/rtgui/options.h
+++ b/rtgui/options.h
@@ -275,6 +275,7 @@ public:
     Glib::ustring clutsDir;
     int rgbDenoiseThreadLimit; // maximum number of threads for the denoising tool ; 0 = use the maximum available
     int maxInspectorBuffers;   // maximum number of buffers (i.e. images) for the Inspector feature
+    int inspectorDelay;
     int clutCacheSize;
     bool filledProfile;  // Used as reminder for the ProfilePanel "mode"
     prevdemo_t prevdemo; // Demosaicing method used for the <100% preview