Add Softkey UIState to Viewer

tools/viewer/sk_app/CommandSet.h

Index: tools/viewer/sk_app/CommandSet.h
diff --git a/tools/viewer/sk_app/CommandSet.h b/tools/viewer/sk_app/CommandSet.h
index 5e6373c9354b8dcda97edd5b8a7b8ded8b61ba74..4cbb367e01cf99269817f76c34ead05fc2672f56 100644
--- a/tools/viewer/sk_app/CommandSet.h
+++ b/tools/viewer/sk_app/CommandSet.h
@@ -12,6 +12,7 @@
 #include "Window.h"
 
 #include <functional>
+#include <vector>
 
 class SkCanvas;
 
@@ -40,6 +41,7 @@ public:
     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);
@@ -48,6 +50,8 @@ public:
 
     void drawHelp(SkCanvas* canvas);
 
+    std::vector<SkString> getCommandsAsSoftkeys() const;
+
 private:
     struct Command {
         enum CommandType {
@@ -86,6 +90,10 @@ private:
         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);