src/shutdown-dialog.vala: keep dialog size fixed.

Previously, the dialog resized whenever the timer was shown or hidden.

We want to avoid this, but unfortunately, GTK doesn't provide a way to
hide a widget and retain its size in the parent (for instance, a
container).

To work around this, create a new private class FakeHideLabel,
subclassing Gtk.Label, that exposes a fake_hide () property. If the
property is set to true, the widget is "fake hidden" by changing the
draw () method to first draw normally, and then paint everything fully
transparent.

The usual hide () and show () methods are not used any longer (other
than at widget creation).

Additionally, a dummy text is inserted at widget creation, including
setting the widget to "fake hidden", so that text line actually has a
size.

While this should work fine visually, this WILL definitely create
accessibility issues, which we must fix at a later time.

Fixes: https://github.com/ArcticaProject/arctica-greeter/issues/58

1 files changed, 50 insertions, 5 deletions

diff --git a/src/shutdown-dialog.vala b/src/shutdown-dialog.vala
index aeae991..d243188 100644
--- a/src/shutdown-dialog.vala
+++ b/src/shutdown-dialog.vala
@@ -56,7 +56,7 @@ public class ShutdownDialog : Gtk.Fixed
     private Gtk.Box vbox;
     private DialogButton close_button;
     private Gtk.Box button_box;
-    private Gtk.Label default_action_label;
+    private FakeHideLabel default_action_label;
     private Gtk.EventBox monitor_events;
     private Gtk.EventBox vbox_events;
 
@@ -267,10 +267,12 @@ public class ShutdownDialog : Gtk.Fixed
                 show.connect(() => { button.grab_focus (); });
         }
 
-        default_action_label = new Gtk.Label (null);
+        default_action_label = new FakeHideLabel (null);
         default_action_label.set_line_wrap (true);
         default_action_label.set_alignment (0.0f, 0.5f);
-        default_action_label.visible = false;
+        default_action_label.set_markup ("<span font=\"%s %d\" fgcolor=\"%s\">%s</span>".printf (font_family, font_size_base+1, AGSettings.get_string (AGSettings.KEY_TOGGLEBOX_FONT_FGCOLOR), "Dummy text - users should not see this"));
+        default_action_label.fake_hide = true;
+        default_action_label.show ();
         vbox.pack_start (default_action_label, false, false, 0);
 
         close_button = new DialogButton (Path.build_filename (Config.PKGDATADIR, "dialog_close.png"), Path.build_filename (Config.PKGDATADIR, "dialog_close_highlight.png"), Path.build_filename (Config.PKGDATADIR, "dialog_close_press.png"));
@@ -294,6 +296,7 @@ public class ShutdownDialog : Gtk.Fixed
                 /* Fun begins here, actually trigger option. */
                 var text = _("Executing selected action now.");
                 default_action_label.set_markup ("<span font=\"%s %d\" fgcolor=\"%s\">%s</span>".printf (font_family, font_size_base+1, AGSettings.get_string (AGSettings.KEY_TOGGLEBOX_FONT_FGCOLOR), text));
+                default_action_label.fake_hide = false;
 
                 /*
                  * Note that, if no button is focused, this will do
@@ -327,6 +330,7 @@ public class ShutdownDialog : Gtk.Fixed
         {
             var text = ngettext ("Waiting one more second before executing selected action …", "Waiting %u seconds before executing selected action …", default_action_time_remaining).printf (default_action_time_remaining);
             default_action_label.set_markup ("<span font=\"%s %d\" fgcolor=\"%s\">%s</span>".printf (font_family, font_size_base+1, AGSettings.get_string (AGSettings.KEY_TOGGLEBOX_FONT_FGCOLOR), text));
+            default_action_label.fake_hide = false;
 
             --default_action_time_remaining;
 
@@ -344,7 +348,7 @@ public class ShutdownDialog : Gtk.Fixed
         default_action_time_remaining = AGSettings.get_integer (AGSettings.KEY_SHUTDOWN_DIALOG_TIMEOUT);
         default_action_time_supplemental = DEFAULT_ACTION_SUPPLEMENTAL_TIME;
 
-        default_action_label.hide ();
+        default_action_label.fake_hide = true;
     }
 
     private void default_action_timeout_init ()
@@ -357,7 +361,7 @@ public class ShutdownDialog : Gtk.Fixed
         if (default_action_time_remaining > 0)
         {
             default_action_timeout = GLib.Timeout.add_seconds (1, update_default_action_label);
-            default_action_label.visible = true;
+            default_action_label.show ();
         }
     }
 
@@ -763,3 +767,44 @@ private class DialogButton : Gtk.Button
         base.state_flags_changed (previous_state);
     }
 }
+
+private class FakeHideLabel : Gtk.Label
+{
+    public bool fake_hide_;
+    public bool fake_hide
+    {
+        get
+        {
+            return fake_hide_;
+        }
+        set
+        {
+            fake_hide_ = value;
+            queue_draw ();
+        }
+    }
+
+    public FakeHideLabel (string? text)
+    {
+        Object (label: text);
+        fake_hide = false;
+    }
+
+    public override bool draw (Cairo.Context c)
+    {
+        c.push_group ();
+        base.draw (c);
+        c.pop_group_to_source ();
+
+        if (fake_hide)
+        {
+            c.paint_with_alpha (0);
+        }
+        else
+        {
+            c.paint_with_alpha (1);
+        }
+
+        return false;
+    }
+}