[connections/wip/fullscreen: 5/5] display-view: Add top hotspot for escaping fullscreen

[Felipe Borges <felipeborges src gnome org>]

commit 78ea65ac9d6878db25e6fd6558b8e47011ed7975
Author: Felipe Borges <felipeborges gnome org>
Date:   Wed May 12 10:36:11 2021 +0200

    display-view: Add top hotspot for escaping fullscreen
    
    When hovering the cursor at the top of a fullscreened display, one
    will see the "escape fullscreen button".
    
    Fixes #5

 src/display-view.vala  | 17 +++++++++++++++++
 src/ui/display-view.ui | 18 ++++++++++++++++++
 2 files changed, 35 insertions(+)
---
diff --git a/src/display-view.vala b/src/display-view.vala
index 23fe9a9..ab8c986 100644
--- a/src/display-view.vala
+++ b/src/display-view.vala
@@ -36,6 +36,8 @@ namespace Connections {
 
         [GtkChild]
         private unowned Label size_label;
+        [GtkChild]
+        private unowned Button escape_fullscreen_button;
 
         private Widget? display;
 
@@ -153,5 +155,20 @@ namespace Connections {
                 return false;
             });
         }
+
+        [GtkCallback]
+        private void on_escape_fullscreen_button_clicked () {
+            Application.application.main_window.fullscreened = false;
+            escape_fullscreen_button.visible = false;
+        }
+
+        public override bool motion_notify_event (Gdk.EventMotion event) {
+            if (!Application.application.main_window.fullscreened)
+                return false;
+
+            escape_fullscreen_button.visible = (event.y < 40);
+
+            return base.motion_notify_event (event);
+        }
     }
 }
diff --git a/src/ui/display-view.ui b/src/ui/display-view.ui
index 7bd6f2e..7085faa 100644
--- a/src/ui/display-view.ui
+++ b/src/ui/display-view.ui
@@ -39,6 +39,24 @@
                 </object>
               </child>
 
+              <child type="overlay">
+                <object class="GtkButton" id="escape_fullscreen_button">
+                  <property name="halign">center</property>
+                  <property name="valign">start</property>
+                  <signal name="clicked" handler="on_escape_fullscreen_button_clicked"/>
+                  <style>
+                    <class name="app-notification"/>
+                  </style>
+                  <child>
+                    <object class="GtkImage">
+                      <property name="visible">True</property>
+                      <property name="icon-name">view-fullscreen-symbolic</property>
+                      <property name="icon-size">1</property>
+                    </object>
+                  </child>
+                </object>
+              </child>
+
               <child>
                 <object class="GtkEventBox" id="event_box">
                   <property name="visible">True</property>