From 8a67da69cce509c797234c1015b203c24281c9ef Mon Sep 17 00:00:00 2001
From: Thomas Bernard <miniupnp@free.fr>
Date: Wed, 27 Dec 2017 22:16:48 +0100
Subject: [PATCH] Right click on a layer toggle SOLO / previous state

Previously, if right clicking the current layer which is the only
one shown, then all layers are shown.

Now right clicking twice on the current layer return to the same
state.

see http://pulkomandy.tk/projects/GrafX2/ticket/25
---
 src/layers.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/layers.c b/src/layers.c
index 17aaa873..9a0dbd14 100644
--- a/src/layers.c
+++ b/src/layers.c
@@ -34,7 +34,8 @@
 
 void Layer_activate(int layer, short side)
 {
-  word old_layers;
+  dword old_layers;
+  static dword layers_backup_for_toggle = 0xFFFFFFFF;
 
   if (layer >= Main_backups->Pages->Nb_layers)
     return;
@@ -51,12 +52,14 @@ void Layer_activate(int layer, short side)
       {
         if (Main_layers_visible == (dword)(1<<layer))
         {
-          // Set all layers visible
-          Main_layers_visible = 0xFFFFFFFF;
+          // return to previous state (layers that were on before showing
+          // only this one)
+          Main_layers_visible = layers_backup_for_toggle;
         }
         else
         {
           // Set only this one visible
+          layers_backup_for_toggle = Main_layers_visible;
           Main_layers_visible = 1<<layer;
         }
       }