1 files changed, 69 insertions, 4 deletions

diff --git a/screen_ui.h b/screen_ui.h
index f05761c42..c1222a576 100644
--- a/screen_ui.h
+++ b/screen_ui.h
@@ -20,6 +20,7 @@
 #include <pthread.h>
 #include <stdio.h>
 
+#include <memory>
 #include <string>
 #include <vector>
 
@@ -28,6 +29,70 @@
 // From minui/minui.h.
 struct GRSurface;
 
+// This class maintains the menu selection and display of the screen ui.
+class Menu {
+ public:
+  Menu(bool scrollable, size_t max_items, size_t max_length);
+
+  bool scrollable() const {
+    return scrollable_;
+  }
+
+  int selection() const {
+    return selection_;
+  }
+
+  // Returns count of menu items.
+  size_t ItemsCount() const;
+  // Returns the index of the first menu item.
+  size_t MenuStart() const;
+  // Returns the index of the last menu item + 1.
+  size_t MenuEnd() const;
+
+  // Menu example:
+  // info:                           Android Recovery
+  //                                 ....
+  // help messages:                  Swipe up/down to move
+  //                                 Swipe left/right to select
+  // empty line (horizontal rule):
+  // menu headers:                   Select file to view
+  // menu items:                     /cache/recovery/last_log
+  //                                 /cache/recovery/last_log.1
+  //                                 /cache/recovery/last_log.2
+  //                                 ...
+  const char* const* text_headers() const;
+  std::string TextItem(size_t index) const;
+
+  // Checks if the menu items fit vertically on the screen. Returns true and set the
+  // |cur_selection_str| if the items exceed the screen limit.
+  bool ItemsOverflow(std::string* cur_selection_str) const;
+
+  // Starts the menu with |headers| and |items| in text. Sets the default selection to
+  // |initial_selection|.
+  void Start(const char* const* headers, const char* const* items, int initial_selection);
+
+  // Sets the current selection to |sel|. Handle the overflow cases depending on if the menu is
+  // scrollable.
+  int Select(int sel);
+
+ private:
+  // The menu is scrollable to display more items. Used on wear devices who have smaller screens.
+  const bool scrollable_;
+  // The max number of menu items to fit vertically on a screen.
+  const size_t max_display_items_;
+  // The length of each item to fit horizontally on a screen.
+  const size_t max_item_length_;
+
+  // Internal storage for the menu headers and items in text.
+  const char* const* text_headers_;
+  std::vector<std::string> text_items_;
+
+  // The first item to display on the screen.
+  size_t menu_start_;
+  // Current menu selection.
+  int selection_;
+};
+
 // Implementation of RecoveryUI appropriate for devices with a screen
 // (shows an icon + a progress bar, text logging, menu, etc.)
 class ScreenRecoveryUI : public RecoveryUI {
@@ -44,6 +109,7 @@ class ScreenRecoveryUI : public RecoveryUI {
   };
 
   ScreenRecoveryUI();
+  explicit ScreenRecoveryUI(bool scrollable_menu);
 
   bool Init(const std::string& locale) override;
 
@@ -101,6 +167,7 @@ class ScreenRecoveryUI : public RecoveryUI {
   virtual void draw_background_locked();
   virtual void draw_foreground_locked();
   virtual void draw_screen_locked();
+  virtual void draw_menu_and_text_buffer_locked(const char* const* help_message);
   virtual void update_screen_locked();
   virtual void update_progress_locked();
 
@@ -184,10 +251,8 @@ class ScreenRecoveryUI : public RecoveryUI {
   bool show_text;
   bool show_text_ever;  // has show_text ever been true?
 
-  std::vector<std::string> menu_;
-  const char* const* menu_headers_;
-  bool show_menu;
-  int menu_items, menu_sel;
+  bool scrollable_menu_;
+  std::unique_ptr<Menu> menu_;
 
   // An alternate text screen, swapped with 'text_' when we're viewing a log file.
   char** file_viewer_text_;