From 7c3d6b4c4d53da84d7e3586d2c783f714fc13bfb Mon Sep 17 00:00:00 2001
From: Emma Broman <emmabroman740@gmail.com>
Date: Wed, 12 Jan 2022 09:39:12 +0100
Subject: [PATCH] Change how moveLayer works slightly, so it is easier to use
 in a GUI implementation

* "newPosition" is now considered to be the item's new position (index) in the list
* also update the documentation a little
---
 modules/globebrowsing/globebrowsingmodule.cpp     | 10 ++++++----
 modules/globebrowsing/globebrowsingmodule_lua.inl |  2 +-
 modules/globebrowsing/src/layergroup.cpp          | 11 ++---------
 modules/globebrowsing/src/layergroup.h            |  2 +-
 4 files changed, 10 insertions(+), 15 deletions(-)

diff --git a/modules/globebrowsing/globebrowsingmodule.cpp b/modules/globebrowsing/globebrowsingmodule.cpp
index 56418d997d..96c04f94da 100644
--- a/modules/globebrowsing/globebrowsingmodule.cpp
+++ b/modules/globebrowsing/globebrowsingmodule.cpp
@@ -376,12 +376,14 @@ scripting::LuaLibrary GlobeBrowsingModule::luaLibrary() const {
             "moveLayer",
             &globebrowsing::luascriptfunctions::moveLayer,
             "string, string, number, number",
-            "Rearranges the order of a single layer in a scene graph node. The first "
-            "parameter specifies the scene graph node, the second parameter specifies "
+            "Rearranges the order of a single layer on a globe. The first parameter"
+            "is the identifier of the globe, the second parameter specifies "
             "the name of the layer group, the third parameter is the original position "
             "of the layer that should be moved and the last parameter is the new "
-            "position. The new position may be -1 to place the layer at the top or any "
-            "large number bigger than the number of layers to place it at the bottom."
+            "position in the list. The first position in the list has index 0, and the "
+            "last position is given by the number of layers minus one. The new position "
+            "may be -1 to place the layer at the top or any number bigger than the "
+            "number of layers to place it at the bottom."
         },
         {
             "goToChunk",
diff --git a/modules/globebrowsing/globebrowsingmodule_lua.inl b/modules/globebrowsing/globebrowsingmodule_lua.inl
index 2cb2d26889..2dd7398a66 100644
--- a/modules/globebrowsing/globebrowsingmodule_lua.inl
+++ b/modules/globebrowsing/globebrowsingmodule_lua.inl
@@ -169,7 +169,7 @@ int moveLayer(lua_State* L) {
     }
 
     globebrowsing::LayerGroup& lg = globe->layerManager().layerGroup(group);
-    lg.moveLayers(oldPosition, newPosition);
+    lg.moveLayer(oldPosition, newPosition);
     return 0;
 }
 
diff --git a/modules/globebrowsing/src/layergroup.cpp b/modules/globebrowsing/src/layergroup.cpp
index 65245e6255..3adf42d366 100644
--- a/modules/globebrowsing/src/layergroup.cpp
+++ b/modules/globebrowsing/src/layergroup.cpp
@@ -212,16 +212,9 @@ void LayerGroup::deleteLayer(const std::string& layerName) {
     LERROR("Could not find layer " + layerName);
 }
 
-void LayerGroup::moveLayers(int oldPosition, int newPosition) {
+void LayerGroup::moveLayer(int oldPosition, int newPosition) {
     oldPosition = std::max(0, oldPosition);
-    newPosition = std::min(newPosition, static_cast<int>(_layers.size()));
-
-    // We need to adjust the new position as we first delete the old position, if this
-    // position is before the new position we have reduced the size of the vector by 1 and
-    // need to adapt where we want to put the value in
-    if (oldPosition < newPosition) {
-        newPosition -= 1;
-    }
+    newPosition = std::min(newPosition, static_cast<int>(_layers.size() - 1));
 
     // There are two synchronous vectors that we have to update here.  The _layers vector
     // is used to determine the order while rendering, the _subowners is the order in
diff --git a/modules/globebrowsing/src/layergroup.h b/modules/globebrowsing/src/layergroup.h
index 3b2d2b7148..be133a3dac 100644
--- a/modules/globebrowsing/src/layergroup.h
+++ b/modules/globebrowsing/src/layergroup.h
@@ -52,7 +52,7 @@ struct LayerGroup : public properties::PropertyOwner {
 
     Layer* addLayer(const ghoul::Dictionary& layerDict);
     void deleteLayer(const std::string& layerName);
-    void moveLayers(int oldPosition, int newPosition);
+    void moveLayer(int oldPosition, int newPosition);
 
     /// @returns const vector of all layers
     std::vector<Layer*> layers() const;