[iagno] Introduce GameActionBarPlaceHolder.

[Arnaud B. <arnaudb src gnome org>]

commit f63886b1e1653f860faa49c9509264a7e936d51d
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Mon Dec 30 12:05:15 2019 +0100

    Introduce GameActionBarPlaceHolder.
    
    Copied from Four-in-a-row.

 data/iagno.css                        |  8 +++++++
 data/iagno.gresource.xml              | 25 +++++++++++-----------
 data/ui/base-window.ui                |  2 +-
 data/ui/game-actionbar-placeholder.ui | 30 +++++++++++++++++++++++++++
 src/base-window.vala                  |  8 ++++++-
 src/game-actionbar.vala               | 39 +++++++++++++++++++++++++++++++++++
 src/game-window.vala                  |  6 +++++-
 7 files changed, 103 insertions(+), 15 deletions(-)
---
diff --git a/data/iagno.css b/data/iagno.css
index e4abbfb..7c52f8f 100644
--- a/data/iagno.css
+++ b/data/iagno.css
@@ -82,6 +82,14 @@ label.game-name-label:dir(rtl) {
   margin-right: 12px;
 }
 
+/* the actionbar is in an overlay... */
+actionbar {
+  background-color:@theme_bg_color;
+}
+actionbar:backdrop {
+  background-color:@theme_unfocused_bg_color;
+}
+
 /*\
 * * games buttons
 \*/
diff --git a/data/iagno.gresource.xml b/data/iagno.gresource.xml
index e40753c..c93997f 100644
--- a/data/iagno.gresource.xml
+++ b/data/iagno.gresource.xml
@@ -5,23 +5,24 @@
     <file preprocess="to-pixdata" alias="reversi.png">../data/reversi.png</file>
   </gresource>
   <gresource prefix="/org/gnome/Reversi/ui">
-    <file preprocess="xml-stripblanks" compressed="true" alias="adaptative-window.ui"       
> ui/adaptative-window.ui</file>
-    <file preprocess="xml-stripblanks" compressed="true" alias="base-headerbar.ui"          
> ui/base-headerbar.ui</file>
-    <file preprocess="xml-stripblanks" compressed="true" alias="base-view.ui"               
> ui/base-view.ui</file>
+    <file preprocess="xml-stripblanks" compressed="true" alias="adaptative-window.ui"           
> ui/adaptative-window.ui</file>
+    <file preprocess="xml-stripblanks" compressed="true" alias="base-headerbar.ui"              
> ui/base-headerbar.ui</file>
+    <file preprocess="xml-stripblanks" compressed="true" alias="base-view.ui"                   
> ui/base-view.ui</file>
     <file compressed="true">base-window.css</file>
-    <file preprocess="xml-stripblanks" compressed="true" alias="base-window.ui"             
> ui/base-window.ui</file>
-    <file preprocess="xml-stripblanks" compressed="true" alias="game-actionbar.ui"          
> ui/game-actionbar.ui</file>
-    <file preprocess="xml-stripblanks" compressed="true" alias="game-headerbar.ui"          
> ui/game-headerbar.ui</file>
-    <file preprocess="xml-stripblanks" compressed="true" alias="history-button.ui"          
> ui/history-button.ui</file>
+    <file preprocess="xml-stripblanks" compressed="true" alias="base-window.ui"                 
> ui/base-window.ui</file>
+    <file preprocess="xml-stripblanks" compressed="true" alias="game-actionbar.ui"              
> ui/game-actionbar.ui</file>
+    <file preprocess="xml-stripblanks" compressed="true" alias="game-actionbar-placeholder.ui"  
> ui/game-actionbar-placeholder.ui</file>
+    <file preprocess="xml-stripblanks" compressed="true" alias="game-headerbar.ui"              
> ui/game-headerbar.ui</file>
+    <file preprocess="xml-stripblanks" compressed="true" alias="history-button.ui"              
> ui/history-button.ui</file>
     <file compressed="true">iagno.css</file>
     <file compressed="true">new-game-screen.css</file>
-    <file preprocess="xml-stripblanks" compressed="true" alias="new-game-screen.ui"         
> ui/new-game-screen.ui</file>
-    <file preprocess="xml-stripblanks" compressed="true" alias="notifications-revealer.ui"  
> ui/notifications-revealer.ui</file>
+    <file preprocess="xml-stripblanks" compressed="true" alias="new-game-screen.ui"             
> ui/new-game-screen.ui</file>
+    <file preprocess="xml-stripblanks" compressed="true" alias="notifications-revealer.ui"      
> ui/notifications-revealer.ui</file>
     <file>noise.png</file>
-    <file preprocess="xml-stripblanks" compressed="true" alias="overlayed-list.ui"          
> ui/overlayed-list.ui</file>
-    <file preprocess="xml-stripblanks" compressed="true" alias="registry-placeholder.ui"    
> ui/registry-placeholder.ui</file>
+    <file preprocess="xml-stripblanks" compressed="true" alias="overlayed-list.ui"              
> ui/overlayed-list.ui</file>
+    <file preprocess="xml-stripblanks" compressed="true" alias="registry-placeholder.ui"        
> ui/registry-placeholder.ui</file>
   </gresource>
   <gresource prefix="/org/gnome/Reversi/gtk">
-    <file preprocess="xml-stripblanks" alias="help-overlay.ui">ui/help-overlay.ui</file>
+    <file preprocess="xml-stripblanks" compressed="true" alias="help-overlay.ui"                
> ui/help-overlay.ui</file>
   </gresource>
 </gresources>
diff --git a/data/ui/base-window.ui b/data/ui/base-window.ui
index 049b28b..382d39a 100644
--- a/data/ui/base-window.ui
+++ b/data/ui/base-window.ui
@@ -21,7 +21,7 @@
     <property name="visible">False</property>
     <signal name="key-press-event" handler="on_key_press_event"/>
     <child>
-      <object class="GtkOverlay">
+      <object class="GtkOverlay" id="main_overlay">
         <property name="visible">True</property>
         <child>
           <object class="GtkGrid" id="main_grid">
diff --git a/data/ui/game-actionbar-placeholder.ui b/data/ui/game-actionbar-placeholder.ui
new file mode 100644
index 0000000..2b69eee
--- /dev/null
+++ b/data/ui/game-actionbar-placeholder.ui
@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+   This file is part of a GNOME game
+
+   Copyright (C) 2019 – Arnaud Bonatti <arnaud bonatti gmail com>
+
+   This application is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This application is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License along
+   with this application.  If not, see <https://www.gnu.org/licenses/>.
+-->
+<interface>
+  <requires lib="gtk+" version="3.12"/>
+  <template class="GameActionBarPlaceHolder" parent="GtkRevealer">
+    <property name="visible">True</property>
+    <child>
+      <object class="GtkDrawingArea" id="placeholder_child">
+        <property name="visible">True</property>
+      </object>
+    </child>
+  </template>
+</interface>
diff --git a/src/base-window.vala b/src/base-window.vala
index 64e8f80..fe6369d 100644
--- a/src/base-window.vala
+++ b/src/base-window.vala
@@ -69,11 +69,17 @@ private class BaseWindow : AdaptativeWindow, AdaptativeWidget
     }
 
     /*\
-    * * main grid
+    * * main layout
     \*/
 
     [GtkChild] private Grid main_grid;
     [GtkChild] private Button unfullscreen_button;
+    [GtkChild] private Overlay main_overlay;
+
+    protected void add_to_main_overlay (Widget widget)
+    {
+        main_overlay.add_overlay (widget);
+    }
 
     protected void add_to_main_grid (Widget widget)
     {
diff --git a/src/game-actionbar.vala b/src/game-actionbar.vala
index 314ab40..e59bfdc 100644
--- a/src/game-actionbar.vala
+++ b/src/game-actionbar.vala
@@ -89,3 +89,42 @@ private class GameActionBar : Revealer, AdaptativeWidget
         update_visibility ();
     }
 }
+
+[GtkTemplate (ui = "/org/gnome/Reversi/ui/game-actionbar-placeholder.ui")]
+private class GameActionBarPlaceHolder : Revealer, AdaptativeWidget
+{
+    [GtkChild] private Widget placeholder_child;
+    private GameActionBar actionbar;
+
+    internal GameActionBarPlaceHolder (GameActionBar _actionbar)
+    {
+        actionbar = _actionbar;
+        actionbar.size_allocate.connect (set_height);
+        set_height ();
+        set_reveal_child (true);    // seems like setting it in the UI file does not work, while it is OK 
for GameActionBar...
+    }
+
+    private void set_height ()
+    {
+        Requisition natural_size;
+        Widget? widget = actionbar.get_child ();
+        if (widget == null)
+            return;
+        ((!) widget).get_preferred_size (/* minimum size */ null, out natural_size);
+        placeholder_child.height_request = natural_size.height;
+    }
+
+    /*\
+    * * adaptative stuff
+    \*/
+
+    private bool is_extra_thin = true;
+    protected override void set_window_size (AdaptativeWidget.WindowSize new_size)
+    {
+        bool _is_extra_thin = AdaptativeWidget.WindowSize.is_extra_thin (new_size);
+        if (_is_extra_thin == is_extra_thin)
+            return;
+        is_extra_thin = _is_extra_thin;
+        set_reveal_child (is_extra_thin);
+    }
+}
diff --git a/src/game-window.vala b/src/game-window.vala
index 86baa63..19bcfa9 100644
--- a/src/game-window.vala
+++ b/src/game-window.vala
@@ -54,11 +54,15 @@ private class GameWindow : BaseWindow, AdaptativeWidget
         game_view = _game_view;
         actionbar = _actionbar;
 
-        add_to_main_grid (actionbar);
+        GameActionBarPlaceHolder actionbar_placeholder = new GameActionBarPlaceHolder (actionbar);
+        add_to_main_grid (actionbar_placeholder);
+        add_to_main_overlay (actionbar);
+        actionbar.valign = Align.END;
 
         add_adaptative_child ((AdaptativeWidget) new_game_screen);
         add_adaptative_child ((AdaptativeWidget) game_view);
         add_adaptative_child ((AdaptativeWidget) actionbar);
+        add_adaptative_child ((AdaptativeWidget) actionbar_placeholder);
 
         /* CSS */
         if (css_resource != null)