A few null checks

Author: lainsce

lib/Models/Window.vala

@@ -28,7 +28,7 @@ public class He.Window : Gtk.Window {
     /**
      * The parent window of this window. If this is null, then this is a top-level window.
      */
-    private new Gtk.Window ? _parent;
+    private new Gtk.Window ? _parent = null;
     public new Gtk.Window ? parent {
         get {
             return this.get_transient_for ();

lib/Widgets/Chip.vala

@@ -46,18 +46,21 @@ public class He.Chip : Gtk.ToggleButton, Gtk.Actionable {
     this.add_css_class ("chip");
 
     chip_box = new He.ButtonContent ();
-    chip_box.get_first_child ().get_first_child ().visible = false;
-    chip_box.icon = "";
 
-    notify["active"].connect (() => {
-      if (this.active) {
-        chip_box.get_first_child ().get_first_child ().visible = true;
-        chip_box.icon = "emblem-default-symbolic";
-      } else {
-        chip_box.get_first_child ().get_first_child ().visible = false;
-        chip_box.icon = "";
-      }
-    });
+    if (chip_box.get_first_child ().get_first_child () != null) {
+      chip_box.get_first_child ().get_first_child ().visible = false;
+      chip_box.icon = "";
+
+      notify["active"].connect (() => {
+        if (this.active) {
+          chip_box.get_first_child ().get_first_child ().visible = true;
+          chip_box.icon = "emblem-default-symbolic";
+        } else {
+          chip_box.get_first_child ().get_first_child ().visible = false;
+          chip_box.icon = "";
+        }
+      });
+    }
 
     chip_box.set_parent (this);
   }

lib/Widgets/DatePicker.vala

@@ -117,8 +117,10 @@ private class He.CalendarWidget : He.Bin {
             margin_start = 18,
             tooltip_text = _("Select Month")
         };
-        ((Gtk.Label) header_label.get_first_child()).set_width_chars(14);
-        ((Gtk.Label) header_label.get_first_child()).add_css_class("cb-title");
+        if (((Gtk.Label) header_label.get_first_child()) != null) {
+            ((Gtk.Label) header_label.get_first_child()).set_width_chars(14);
+            ((Gtk.Label) header_label.get_first_child()).add_css_class("cb-title");
+        }
         header_label.add_css_class("flat");
         header_label.clicked.connect(() => toggle_view());