[iagno] Highlight playable tiles.

[Arnaud B. <arnaudb src gnome org>]

commit a5e02dcdc5c274f5296fcd9ffb5cc66681a764f0
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Mon Dec 9 17:29:17 2019 +0100

    Highlight playable tiles.

 data/org.gnome.Reversi.gschema.xml |  7 +++++++
 src/iagno.vala                     |  8 +++++++-
 src/reversi-view.vala              | 41 +++++++++++++++++++++++++++++++++-----
 3 files changed, 50 insertions(+), 6 deletions(-)
---
diff --git a/data/org.gnome.Reversi.gschema.xml b/data/org.gnome.Reversi.gschema.xml
index aad02ce..d7b39d8 100644
--- a/data/org.gnome.Reversi.gschema.xml
+++ b/data/org.gnome.Reversi.gschema.xml
@@ -66,6 +66,13 @@
       <!-- Translators: description of a settings key, see 'dconf-editor /org/gnome/iagno/computer-level' -->
       <description>From 1, the easiest, to 3, the hardest.</description>
     </key>
+    <key name="highlight-playable-tiles" type="b">
+      <default>false</default>
+      <!-- Translators: summary of a settings key, see 'dconf-editor 
/org/gnome/iagno/highlight-playable-tiles' -->
+      <summary>A flag to highlight playable tiles</summary>
+      <!-- Translators: description of a settings key, see 'dconf-editor 
/org/gnome/iagno/highlight-playable-tiles' -->
+      <description>If “true”, the tiles where you can play are highlighted.</description>
+    </key>
     <key name="highlight-turnable-tiles" type="b">
       <default>false</default>
       <!-- Translators: summary of a settings key, see 'dconf-editor 
/org/gnome/iagno/highlight-turnable-tiles'; these are not the playable tiles, but the one that could be 
captured by a play -->
diff --git a/src/iagno.vala b/src/iagno.vala
index d7decd3..bee15c7 100644
--- a/src/iagno.vala
+++ b/src/iagno.vala
@@ -384,11 +384,15 @@ private class Iagno : Gtk.Application, BaseApplication
         appearance_menu.append_section (null, section);
 
         section = new GLib.Menu ();
+        /* Translators: hamburger menu "Appearance" submenu entry, in the "Highlight" section; 
highlight-playable-tiles togglebutton (with a mnemonic that appears pressing Alt) */
+        section.append (_("Pla_yable tiles"), "app.highlight-playable-tiles");
+
+
         /* Translators: hamburger menu "Appearance" submenu entry, in the "Highlight" section; 
highlight-capturable-tiles togglebutton (with a mnemonic that appears pressing Alt); these are not the 
playable tiles, but the one that could be captured by a play */
         section.append (_("_Capturable tiles"), "app.highlight-turnable-tiles");
         section.freeze ();
 
-        /* Translators: hamburger menu "Appearance" submenu section header; the section will list several 
game helpers that are done by highlighting tiles on the board; currently, there is only one helper, 
"Capturable tiles"; "Highlights" is probably better understood as a noun than as a verb here */
+        /* Translators: hamburger menu "Appearance" submenu section header; the section lists several game 
helpers that are done by highlighting tiles on the board: "Capturable tiles" and "Playable tiles"; 
"Highlights" is probably better understood as a noun than as a verb here */
         appearance_menu.append_section (_("Highlights"), section);
         appearance_menu.freeze ();
 
@@ -436,6 +440,7 @@ private class Iagno : Gtk.Application, BaseApplication
         set_accels_for_action ("base.toggle-hamburger", {                 "F10"     });
      // set_accels_for_action ("app.help",              {                 "F1"      });
      // set_accels_for_action ("base.about",            {          "<Shift>F1"      });
+        add_action (settings.create_action ("highlight-playable-tiles"));
         add_action (settings.create_action ("highlight-turnable-tiles"));
         if (!alternative_start && !random_start && !usual_start)
             add_action (settings.create_action ("random-start-position"));
@@ -443,6 +448,7 @@ private class Iagno : Gtk.Application, BaseApplication
         add_action (settings.create_action ("theme"));
         add_action (settings.create_action ("type"));        // TODO window action?
 
+        settings.bind ("highlight-playable-tiles", view, "show-playable-tiles", SettingsBindFlags.GET);
         settings.bind ("highlight-turnable-tiles", view, "show-turnable-tiles", SettingsBindFlags.GET);
         settings.bind ("theme",                    view, "theme",               SettingsBindFlags.GET);
 
diff --git a/src/reversi-view.vala b/src/reversi-view.vala
index 7cb5937..a302c2c 100644
--- a/src/reversi-view.vala
+++ b/src/reversi-view.vala
@@ -22,6 +22,12 @@
 
 private class ReversiView : Gtk.DrawingArea
 {
+    private bool _show_playable_tiles = false;
+    [CCode (notify = false)] internal bool show_playable_tiles
+    {
+        private  get { return _show_playable_tiles; }
+        internal set { _show_playable_tiles = value; if (game_is_set) highlight_playable_tiles (); }
+    }
     [CCode (notify = false)] internal bool show_turnable_tiles { private get; internal set; default = false; 
}
 
     /* Theme */
@@ -193,6 +199,9 @@ private class ReversiView : Gtk.DrawingArea
                 humans_opening_intensity = 0;
 
             queue_draw ();
+
+            if (show_playable_tiles)
+                highlight_playable_tiles ();
         }
     }
 
@@ -633,7 +642,7 @@ private class ReversiView : Gtk.DrawingArea
 
     private inline void add_highlights (Cairo.Context cr)
     {
-        if (playable_tiles_highlight_state == 0)
+        if (!show_playable_tiles && playable_tiles_highlight_state == 0)
             return;
         if (iagno_instance.computer != null && iagno_instance.player_one != game.current_color)
         {
@@ -641,6 +650,15 @@ private class ReversiView : Gtk.DrawingArea
             return;
         }
 
+        if (show_playable_tiles && show_turnable_tiles)
+        {
+            unowned PossibleMove move;
+            if (show_mouse_highlight && game.test_placing_tile (mouse_highlight_x, mouse_highlight_y, out 
move))
+                return;
+            if (show_highlight && game.test_placing_tile (highlight_x, highlight_y, out move))
+                return;
+        }
+
         bool decreasing = playable_tiles_highlight_state > HIGHLIGHT_MAX;
         uint8 intensity;
         if (decreasing)
@@ -654,7 +672,9 @@ private class ReversiView : Gtk.DrawingArea
 
         if (decreasing && intensity == 1)
             init_possible_moves ();
-        else
+        else if (!show_playable_tiles)
+            playable_tiles_highlight_state++;
+        else if (playable_tiles_highlight_state < HIGHLIGHT_MAX)
             playable_tiles_highlight_state++;
     }
     private inline void add_highlight (Cairo.Context cr, uint8 x, uint8 y, uint8 intensity)
@@ -941,6 +961,13 @@ private class ReversiView : Gtk.DrawingArea
             show_highlight = true;
         else if (!show_highlight)
             show_mouse_highlight = true;
+
+        // reload playable tiles
+        if (show_playable_tiles)
+        {
+            init_possible_moves (); // clears previous highlights
+            highlight_playable_tiles (/* force reload */ true);
+        }
     }
     private void get_missing_tile (out uint8 x, out uint8 y)
     {
@@ -1010,8 +1037,11 @@ private class ReversiView : Gtk.DrawingArea
         if (!no_draw)
         {
             update_squares ();
+            playable_tiles_highlight_state = 0;
             if (undoing)
                 update_highlight_after_undo ();
+            else if (show_playable_tiles)
+                highlight_playable_tiles ();
         }
 
         last_state = game.current_state;
@@ -1176,6 +1206,7 @@ private class ReversiView : Gtk.DrawingArea
         notify_final_animation (/* undoing */ true);
         flip_final_result_now = false;
         update_squares ();
+        highlight_playable_tiles ();
 
         return true;
     }
@@ -1268,7 +1299,7 @@ private class ReversiView : Gtk.DrawingArea
                         Source.remove (timeout_id);
                         timeout_id = 0;
                     }
-                    timeout_id = Timeout.add (200, () => {
+                    timeout_id = Timeout.add (show_playable_tiles ? 50 : 200, () => {
                             if (mouse_is_in)
                                 _on_motion (x, y, /* force redraw */ false);
                             timeout_id = 0;
@@ -1708,9 +1739,9 @@ private class ReversiView : Gtk.DrawingArea
             move (x, y);
     }
 
-    private inline void highlight_playable_tiles ()
+    private inline void highlight_playable_tiles (bool force_reload = false)
     {
-        if (playable_tiles_highlight_state != 0)
+        if (!force_reload && playable_tiles_highlight_state != 0)
             return;
 
         SList<PossibleMove?> moves;