[geary/wip/conversation-polish: 26/26] Tidy up placeholder style when it has no text

[Michael Gratton <mjog src gnome org>]

commit 8d1735474061e794bb0331a9dca275b09da2f764
Author: Michael Gratton <mike vee net>
Date:   Sat Feb 2 13:03:45 2019 +1100

    Tidy up placeholder style when it has no text

 .../components/components-placeholder-pane.vala    | 27 ++++++++++++++++++++--
 ui/geary.css                                       |  2 +-
 2 files changed, 26 insertions(+), 3 deletions(-)
---
diff --git a/src/client/components/components-placeholder-pane.vala 
b/src/client/components/components-placeholder-pane.vala
index ec8926f9..1851356b 100644
--- a/src/client/components/components-placeholder-pane.vala
+++ b/src/client/components/components-placeholder-pane.vala
@@ -11,6 +11,10 @@
 [GtkTemplate (ui = "/org/gnome/Geary/components-placeholder-pane.ui")]
 public class Components.PlaceholderPane : Gtk.Grid {
 
+
+    public const string CLASS_HAS_TEXT = "geary-has-text";
+
+
     /** The icon name of the pane's image. */
     public string icon_name {
         owned get { return this.placeholder_image.icon_name; }
@@ -20,13 +24,19 @@ public class Components.PlaceholderPane : Gtk.Grid {
     /** The text of the pane's title label. */
     public string title {
         get { return this.title_label.get_text(); }
-        set { this.title_label.set_text(value); }
+        set {
+            this.title_label.set_text(value);
+            update();
+        }
     }
 
     /** The text of the pane's sub-title label. */
     public string subtitle {
         get { return this.subtitle_label.get_text(); }
-        set { this.subtitle_label.set_text(value); }
+        set {
+            this.subtitle_label.set_text(value);
+            update();
+        }
     }
 
     [GtkChild]
@@ -38,4 +48,17 @@ public class Components.PlaceholderPane : Gtk.Grid {
     [GtkChild]
     private Gtk.Label subtitle_label;
 
+
+    private void update() {
+        if (Geary.String.is_empty_or_whitespace(this.title_label.get_text())) {
+            this.title_label.hide();
+        }
+        if (Geary.String.is_empty_or_whitespace(this.subtitle_label.get_text())) {
+            this.subtitle_label.hide();
+        }
+        if (this.title_label.visible || this.subtitle_label.visible) {
+            get_style_context().add_class(CLASS_HAS_TEXT);
+        }
+    }
+
 }
diff --git a/ui/geary.css b/ui/geary.css
index e18e8ceb..a11f940f 100644
--- a/ui/geary.css
+++ b/ui/geary.css
@@ -184,7 +184,7 @@ grid.geary-message-summary {
 
 /* PlaceholderPane  */
 
-.geary-placeholder-pane > image {
+.geary-placeholder-pane.geary-has-text > image {
   margin-bottom: 12px;
 }
 .geary-placeholder-pane > .title {