Add Softkey UIState to Viewer

tools/viewer/sk_app/CommandSet.h

 /*
 * Copyright 2016 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 
 #ifndef CommandSet_DEFINED
 #define CommandSet_DEFINED
 
 #include "SkString.h"
 #include "Window.h"
 
 #include <functional>
+#include <vector>
 
 class SkCanvas;
 
 namespace sk_app {
 
 /**
  * Helper class used by applications that want to hook keypresses to trigger events.
  *
  * An app can simply store an instance of CommandSet and then use it as follows:
  * 1) Attach to the Window at initialization time. This registers key handlers on the window.
  * 2) Register commands to be executed for characters or keys. Each command needs a Group and a
  *    description (both just strings). Commands attached to Keys (rather than characters) also need
  *    a displayable name for the Key. Finally, a function to execute when the key or character is
  *    pressed must be supplied. The easiest option to is pass in a lambda that captures [this]
  *    (your application object), and performs whatever action is desired.
  * 3) At the end of your onPaint, call drawHelp, and pass in the application's canvas.
 
  * The CommandSet always binds 'h' to cycle through two different help screens. The first shows
  * all commands, organized by Group (with headings for each Group). The second shows all commands
  * alphabetically by key/character.
  */
 class CommandSet {
 public:
     CommandSet();
 
     void attach(Window* window);
     bool onKey(sk_app::Window::Key key, sk_app::Window::InputState state, uint32_t modifiers);
     bool onChar(SkUnichar, uint32_t modifiers);
+    bool onSoftkey(const SkString& softkey);
 
     void addCommand(SkUnichar c, const char* group, const char* description,
                     std::function<void(void)> function);
     void addCommand(Window::Key k, const char* keyName, const char* group, const char* description,
                     std::function<void(void)> function);
 
     void drawHelp(SkCanvas* canvas);
 
+    std::vector<SkString> getCommandsAsSoftkeys() const;
+
 private:
     struct Command {
         enum CommandType {
             kChar_CommandType,
             kKey_CommandType,
         };
 
         Command(SkUnichar c, const char* group, const char* description,
                 std::function<void(void)> function)
             : fType(kChar_CommandType)
@@ skipping 18 matching lines @@
         SkUnichar fChar;
 
         // For kKey_CommandType
         Window::Key fKey;
 
         // Common to all command types
         SkString fKeyName;
         SkString fGroup;
         SkString fDescription;
         std::function<void(void)> fFunction;
+
+        SkString getSoftkeyString() const {
+            return SkStringPrintf("%s (%s)", fKeyName.c_str(), fDescription.c_str());
+        }
     };
 
     static bool compareCommandKey(const Command& first, const Command& second);
     static bool compareCommandGroup(const Command& first, const Command& second);
 
     enum HelpMode {
         kNone_HelpMode,
         kGrouped_HelpMode,
         kAlphabetical_HelpMode,
     };
 
     Window*           fWindow;
     SkTArray<Command> fCommands;
     HelpMode          fHelpMode;
 };
 
 }   // namespace sk_app
 
 #endif