[414174] - Panel background transition color bug

Summary:
Added animation on background color change.
Removed test for background color that is not needed any more.

BUG:414174
FIXED-IN:0.9.5

Reviewers: mvourlakos

Reviewed By: mvourlakos

Subscribers: ognarb, plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D25392

containment/package/contents/ui/PanelBox.qml

@@ -521,13 +521,7 @@ Item{
                 return 0;
             }
 
-            backgroundColor: {
-                if (busyBackground || coloredView) {
-                    return colorizerManager.backgroundColor;
-                }
-
-                return "transparent";
-            }
+            backgroundColor: colorizerManager.backgroundColor
 
             borderWidth: 1
             borderColor: backgroundColor
@@ -568,6 +562,16 @@ Item{
                 enabled: !Latte.WindowSystem.compositingActive
                 NumberAnimation { duration: 0 }
             }
+                        
+            Behavior on backgroundColor{
+                enabled: Latte.WindowSystem.compositingActive
+                ColorAnimation { duration: barLine.animationTime }
+            }
+
+            Behavior on backgroundColor{
+                enabled: !Latte.WindowSystem.compositingActive
+                ColorAnimation { duration: 0 }
+            }
         }
 
         //! Outline drawing