Tied in my recent Android flick gesture addition to a Scroll() function. GameState now has a virtual function OnScroll() call that, by default is a no-op; each game state can choose to override how to respond to flick gestures. I've added one such override in the Deck Editor so that a flick up/down acts like the psp button up/down for scrolling between color filters.

JGE/include/JApp.h

@@ -82,6 +82,8 @@ public:
 	///
 	//////////////////////////////////////////////////////////////////////////
 	virtual void Resume() = 0;
+
+    virtual void OnScroll(int inXVelocity, int inYVelocity) = 0;
 };
 
 

JGE/include/JGE.h

@@ -319,6 +319,10 @@ class JGE
   // Returns false if nothing has been clicked, true otherwise
   bool GetLeftClickCoordinates(int& x, int& y);
 
+
+  // Scroll events - currently triggered by SDL JOYBALL events
+  void Scroll(int inXVelocity, int inYVelocity);
+
   //////////////////////////////////////////////////////////////////////////
   /// Get if the system is ended/paused or not.
   ///

JGE/src/JGE.cpp

@@ -78,7 +78,8 @@ void JGE::PressKey(const LocalKeySym sym)
     const pair<keycodes_it, keycodes_it> rng = keyBinds.equal_range(sym);
     if (rng.first == rng.second)
         keyBuffer.push(triplet(sym, JGE_BTN_NONE, false));
-  else for (keycodes_it it = rng.first; it != rng.second; ++it) {
+    else for (keycodes_it it = rng.first; it != rng.second; ++it)
+    {
 #if defined (WIN32) || defined (LINUX)
         if (JGE_BTN_FULLSCREEN == it->second) JGEToggleFullscreen();
 #endif
@@ -185,10 +186,17 @@ void JGE::Update(float dt)
 {
     for (map<JButton, float>::iterator it = holds.begin(); it != holds.end(); ++it)
     {
-      if (it->second < 0) { keyBuffer.push(triplet(LOCAL_KEY_NONE, it->first, true)); it->second = REPEAT_PERIOD; }
+        if (it->second < 0)
+        {
+            keyBuffer.push(triplet(LOCAL_KEY_NONE, it->first, true));
+            it->second = REPEAT_PERIOD;
+        }
         it->second -= dt;
     }
-  if (mApp != NULL) mApp->Update();
+
+    if (mApp != NULL)
+        mApp->Update();
+    
     oldHolds = holds;
 }
 
@@ -259,8 +267,15 @@ void JGE::ResetBindings()
 }
 
 
-JGE::keybindings_it JGE::KeyBindings_begin() { return keyBinds.begin(); }
-JGE::keybindings_it JGE::KeyBindings_end()   { return keyBinds.end(); }
+JGE::keybindings_it JGE::KeyBindings_begin()
+{
+    return keyBinds.begin();
+}
+
+JGE::keybindings_it JGE::KeyBindings_end()
+{
+    return keyBinds.end();
+}
 
 void JGE::ResetInput()
 {
@@ -478,14 +493,16 @@ void JGE::Destroy()
     }
 }
 
-void JGE::SetARGV(int argc, char * argv[]){
+void JGE::SetARGV(int argc, char * argv[])
+{
     for (int i = 0; i < argc; ++i){
         string s = argv[i];
         mArgv.push_back(s);
     }
 }
 
-std::vector<std::string> JGE::GetARGV() {
+std::vector<std::string> JGE::GetARGV()
+{
     return mArgv;
 }
 
@@ -515,7 +532,6 @@ void JGE::printf(const char *format, ...)
     va_start(list, format);
     vsprintf(mDebuggingMsg, format, list);
     va_end(list);
-
 }
 
 void JGE::Pause()
@@ -526,7 +542,6 @@ void JGE::Pause()
     if (mApp != NULL) mApp->Pause();
 }
 
-
 void JGE::Resume()
 {
     if (mPaused)
@@ -544,5 +559,13 @@ void JGE::Assert(const char *filename, long lineNumber)
     mCriticalAssert = true;
 }
 
+void JGE::Scroll(int inXVelocity, int inYVelocity)
+{
+    if (mApp != NULL)
+    {
+        mApp->OnScroll(inXVelocity, inYVelocity);
+    }
+}
+
 std::queue< pair< pair<LocalKeySym, JButton>, bool> > JGE::keyBuffer;
 std::multimap<LocalKeySym, JButton> JGE::keyBinds;

JGE/src/SDLmain.cpp

@@ -45,6 +45,17 @@ const int kHitzonePliancy = 50;
 // tick value equates to ms
 const int kTapEventTimeout = 250;
 
+
+uint64_t	lastTickCount;
+JGE* g_engine = NULL;
+JApp* g_app = NULL;
+JGameLauncher* g_launcher = NULL;
+
+class SdlApp;
+
+SdlApp *g_SdlApp = NULL;
+
+
 class SdlApp
 {
 public: /* For easy interfacing with JGE static functions */
@@ -215,6 +226,7 @@ public:
 
         case SDL_JOYBALLMOTION:
             DebugTrace("Flick gesture detected, x: " << Event->jball.xrel << ", y: " << Event->jball.yrel);
+            g_engine->Scroll(Event->jball.xrel, Event->jball.yrel);
             break;
         }
 	}
@@ -228,14 +240,6 @@ public:
 	}
 };
 
-uint64_t	lastTickCount;
-JGE* g_engine = NULL;
-JApp* g_app = NULL;
-JGameLauncher* g_launcher = NULL;
-SdlApp *g_SdlApp = NULL;
-
-
-
 static const struct { LocalKeySym keysym; JButton keycode; } gDefaultBindings[] =
 {  
 	/* windows controls */

projects/mtg/include/GameApp.h

@@ -89,6 +89,8 @@ public:
     virtual void Pause();
     virtual void Resume();
 
+    virtual void OnScroll(int inXVelocity, int inYVelocity);
+
     void LoadGameStates();
     void SetNextState(int state);
     void DoTransition(int trans, int tostate, float dur = -1, bool animonly = false);

projects/mtg/include/GameState.h

@@ -55,6 +55,10 @@ public:
     virtual void Start(){}
     virtual void End(){}
 
+    virtual void OnScroll(int inXVelocity, int inYVelocity)
+    {
+    }
+
     virtual void Update(float dt) = 0;
     virtual void Render() = 0;
 

projects/mtg/include/GameStateDeckViewer.h

@@ -141,6 +141,8 @@ public:
     int loadDeck(int deckid);
     void LoadDeckStatistics(int deckId);
 
+    void OnScroll(int inXVelocity, int inYVelocity);
+
     void buildEditorMenu();
     virtual void ButtonPressed(int controllerId, int controlId);
 };

projects/mtg/src/GameApp.cpp

@@ -424,6 +424,14 @@ void GameApp::Render()
 
 }
 
+void GameApp::OnScroll(int inXVelocity, int inYVelocity)
+{
+    if (mCurrentState != NULL)
+    {
+        mCurrentState->OnScroll(inXVelocity, inYVelocity);
+    }
+}
+
 void GameApp::SetNextState(int state)
 {
     mNextState = mGameStates[state];

projects/mtg/src/GameStateDeckViewer.cpp

@@ -1668,3 +1668,12 @@ void GameStateDeckViewer::ButtonPressed(int controllerId, int controlId)
     }
 }
 
+void GameStateDeckViewer::OnScroll(int inXVelocity, int inYVelocity)
+{
+    if (abs(inYVelocity) > 300)
+    {
+        bool flickUpwards = (inYVelocity < 0);
+        mEngine->HoldKey_NoRepeat(flickUpwards ? JGE_BTN_DOWN : JGE_BTN_UP);
+
+    }
+}