+
+```
+@startuml
+
+title show/hide onscreen phase
+
+actor user
+entity "homescreen-service" as hss
+entity App
+entity onscreenapp
+entity windowmanager as wm
+
+== show onscreen ==
+user->App: the operation request onscreen
+App->hss: showWindow()
+note over App,hss
+{"application_id":"onscreenapp",
+"parameter":{"area":"display area", "file":"qml file path",
+"data":{"the datas to onscreen qml"}}}
+end note
+
+hss->onscreenapp: push showWindow event
+note over hss,onscreenapp
+{"application_id":"onscreenapp",
+"parameter":{"area":"display area", "file":"qml file path",
+"data":{"the datas to onscreen qml"},
+<font color=red >"replyto":"caller application id"
+}}
+end note
+
+onscreenapp->onscreenapp: get and save parameters
+onscreenapp->wm: activateWindow("onscreeapp", "display area")
+alt can show
+wm-->onscreenapp: push syncDraw event
+onscreenapp->wm: endDraw("onscreeapp")
+onscreenapp->onscreenapp: load and display qml file
+else can't show
+note over onscreenapp,wm
+do nothing
+end note
+end
+
+== hide onscreen ==
+
+user->onscreenapp: tap onscreen's button
+onscreenapp->hss: replyShowWindow()
+note over onscreenapp,hss
+{"application_id":"the application id who called onscreenapp",
+"parameter": {"buttonName": "VOLUME_UP", "buttonPressMode": "shortPress", "buttonPressState": "release"}}
+end note
+hss->App: push replyShowWindow event
+App->App: call reply function
+App->hss: hideWindow("onscreenapp")
+hss->onscreenapp: push hideWindow event
+note over hss,onscreenapp
+{"application_id":"request hideWindow application id"}
+end note
+onscreenapp->wm: deactivateWindow("onscreenapp");
+onscreenapp->onscreenapp: hide window
+
+@enduml
+```
+
+```
+@startuml
+
+title show notification on HomeScreen top area
+
+entity "homescreen-service" as hss
+entity homescreen
+entity App
+
+App->hss: showNotification()
+note over App,hss
+{"icon":"display icon", "text":"display text"}
+end note
+hss-> homescreen: push showNotification event
+note over hss,homescreen
+{"application_id":"request application id",
+"parameter":{"icon":"display icon", "text":"display text"}}
+end note
+
+homescreen->homescreen: display notification message 3s
+
+@enduml
+```
+
+```
+@startuml
+
+title show information on HomeScreen bottom area
+
+entity "homescreen-service" as hss
+entity homescreen
+entity App
+
+App->hss: showInformation()
+note over hss
+{"info":"display information"}
+end note
+hss-> homescreen: push showInformation event
+
+homescreen->homescreen: display information message 3s
+
+@enduml
+```