Make StatusBarView work with hotkeys

- StatusItem can now define a hotkey which is then
  bound to its action.
- In catalog app replace use of raw key event to
  item's hotkey for status bar visibility.
- Various doc updates.
- Relates #826

spring-shell-docs/modules/ROOT/nav.adoc

@@ -56,6 +56,7 @@
 ** xref:tui/intro/index.adoc[]
 *** xref:tui/intro/terminalui.adoc[]
 ** xref:tui/views/index.adoc[]
+*** xref:tui/views/app.adoc[]
 *** xref:tui/views/box.adoc[]
 *** xref:tui/views/button.adoc[]
 *** xref:tui/views/dialog.adoc[]
@@ -63,6 +64,7 @@
 *** xref:tui/views/list.adoc[]
 *** xref:tui/views/menu.adoc[]
 *** xref:tui/views/menubar.adoc[]
+*** xref:tui/views/statusbar.adoc[]
 ** xref:tui/events/index.adoc[]
 *** xref:tui/events/eventloop.adoc[]
 *** xref:tui/events/key.adoc[]

spring-shell-docs/modules/ROOT/pages/tui/views/app.adoc

@@ -0,0 +1,41 @@
+= AppView
+:page-section-summary-toc: 1
+
+ifndef::snippets[:snippets: ../../../../../src/test/java/org/springframework/shell/docs]
+
+_AppView_ is a base implementation providing functionality to draw opinionated _application view_.
+Inherits xref:tui/views/box.adoc[].
+
+Generic idea is to have menu and status views which typically are xref:tui/views/menubar.adoc[] and
+xref:tui/views/statusbar.adoc[] respectively. Main content view is then whatever user want to show
+in it.
+
+[source, text]
+----
+┌──────────────────────────┐
+│           Menu           │
+├──────────────────────────┤
+│                          │
+│           Main           │
+│                          │
+├──────────────────────────┤
+│          Status          │
+└──────────────────────────┘
+----
+
+== Key Handling
+If menu has a focus key handling is processed there, then main is consulted for handling.
+Lastly cursor left/right are processed to dispatch _AppViewEvent_.
+
+== HotKey Handling
+Hotkeys are processed in order of _main_, _menu_ and _status_.
+
+== Events
+.AppView Events
+|===
+|Event |Description
+
+|AppViewEvent
+|Direction for a next selection.
+
+|===

spring-shell-docs/modules/ROOT/pages/tui/views/menubar.adoc

@@ -7,6 +7,13 @@ ifndef::snippets[:snippets: ../../../../../src/test/java/org/springframework/she
 _MenuBarView_ is a base implementation providing functionality to draw a menu bar.
 Inherits xref:tui/views/box.adoc[].
 
+[source, text]
+----
+┌─────────────────────────────┐
+│ File Help                   │
+└─────────────────────────────┘
+----
+
 == Default Bindings
 Default _key bindigs_ are:
 

spring-shell-docs/modules/ROOT/pages/tui/views/statusbar.adoc

@@ -0,0 +1,48 @@
+= StatusBarView
+:page-section-summary-toc: 1
+
+ifndef::snippets[:snippets: ../../../../../src/test/java/org/springframework/shell/docs]
+
+_StatusBarView_ is a base implementation providing functionality to draw a status bar.
+Inherits xref:tui/views/box.adoc[].
+
+[source, text]
+----
+┌─────────────────────────────┐
+│ Item1 | Item2 | Item3       │
+└─────────────────────────────┘
+----
+
+You can create a simple status bar with an item:
+
+[source, java, indent=0]
+----
+include::{snippets}/StatusBarViewSnippets.java[tag=simple]
+----
+
+Constructor can take array form which allows to lay out simple
+item definitions in a _dsl_ style.
+
+[source, java, indent=0]
+----
+include::{snippets}/StatusBarViewSnippets.java[tag=viaarray]
+----
+
+Items support runnable actions which generally as executed when
+item is selected. It can also get attached to a hot key.
+
+[source, java, indent=0]
+----
+include::{snippets}/StatusBarViewSnippets.java[tag=items]
+----
+
+
+== Events
+.StatusBarView Events
+|===
+|Event |Description
+
+|StatusBarViewOpenSelectedItemEvent
+|StatusItem is selected.
+
+|===