Gestures: fix running on win XP

Potential fix, by dynamically linking SetGestureConfig

src/Gui/View3DInventorViewer.cpp

@@ -219,16 +219,25 @@ class Gui::ViewerEventFilter : public QObject
         if (obj->isWidgetType()) {
             View3DInventorViewer* v = dynamic_cast<View3DInventorViewer*>(obj);
             if(v) {
-                if(! v->isWinGesturesTuned) {
-                    v->isWinGesturesTuned = true;
+                /* Internally, Qt seems to set up the gestures upon showing the
+                 * widget (but after this event is processed), thus invalidating
+                 * our settings. This piece takes care to retune gestures on the
+                 * next event after the show event.
+                 */
+                if(v->winGestureTuneState == View3DInventorViewer::ewgtsNeedTuning) {
                     try{
                         WinNativeGestureRecognizerPinch::TuneWindowsGestures(v);
+                        v->winGestureTuneState = View3DInventorViewer::ewgtsTuned;
+                    } catch (Base::Exception &e) {
+                        Base::Console().Warning("Failed to TuneWindowsGestures. Error: %s\n",e.what());
+                        v->winGestureTuneState = View3DInventorViewer::ewgtsDisabled;
                     } catch (...){
-                        Base::Console().Warning("Failed to TuneWindowsGestures.\n");
+                        Base::Console().Warning("Failed to TuneWindowsGestures. Unknown error.\n");
+                        v->winGestureTuneState = View3DInventorViewer::ewgtsDisabled;
                     }
                 }
-                if (event->type() == QEvent::Show)
-                    v->isWinGesturesTuned = false;//internally, Qt seems to set up the gestures upon showing the widget (but after this event is processed), thus invalidating our settings. Needs to be re-tuned asap.
+                if (event->type() == QEvent::Show && v->winGestureTuneState == View3DInventorViewer::ewgtsTuned)
+                    v->winGestureTuneState = View3DInventorViewer::ewgtsNeedTuning;
 
             }
         }
@@ -485,18 +494,25 @@ void View3DInventorViewer::init()
     getEventFilter()->registerInputDevice(new SpaceNavigatorDevice);
     getEventFilter()->registerInputDevice(new GesturesDevice(this));
 
-    this->grabGesture(Qt::PanGesture);
-    this->grabGesture(Qt::PinchGesture);
-#ifdef GESTURE_MESS
-    {
-        static WinNativeGestureRecognizerPinch* recognizer;//static to avoid creating more than one recognizer, thus causing memory leak and gradual slowdown
-        if(recognizer == 0){
-            recognizer = new WinNativeGestureRecognizerPinch;
-            recognizer->registerRecognizer(recognizer); //From now on, Qt owns the pointer.
+    this->winGestureTuneState = View3DInventorViewer::ewgtsDisabled;
+    try{
+        this->grabGesture(Qt::PanGesture);
+        this->grabGesture(Qt::PinchGesture);
+    #ifdef GESTURE_MESS
+        {
+            static WinNativeGestureRecognizerPinch* recognizer;//static to avoid creating more than one recognizer, thus causing memory leak and gradual slowdown
+            if(recognizer == 0){
+                recognizer = new WinNativeGestureRecognizerPinch;
+                recognizer->registerRecognizer(recognizer); //From now on, Qt owns the pointer.
+            }
         }
+        this->winGestureTuneState = View3DInventorViewer::ewgtsNeedTuning;
+    #endif
+    } catch (Base::Exception &e) {
+        Base::Console().Warning("Failed to set up gestures. Error: %s\n", e.what());
+    } catch (...) {
+        Base::Console().Warning("Failed to set up gestures. Unknown error.\n");
     }
-    this->isWinGesturesTuned = false;
-#endif
 
     //create the cursors
     QBitmap cursor = QBitmap::fromData(QSize(ROTATE_WIDTH, ROTATE_HEIGHT), rotate_bitmap);

src/Gui/View3DInventorViewer.h

@@ -357,12 +357,13 @@ class GuiExport View3DInventorViewer : public Quarter::SoQTQuarterAdaptor, publi
     SbBool processSoEventBase(const SoEvent * const ev);
     void printDimension();
     void selectAll();
-    /** A flag. If false, gestures on windows will get tuned(or re-tuned)
-     *  upon the first event that arrives to eventFilter. This is needed to
-     *  tune windows gestures after Qt does it internally, since its settings
-     *  are not all right for us.
-     */
-    bool isWinGesturesTuned;
+
+    enum eWinGestureTuneState{
+        ewgtsDisabled, //suppress tuning/re-tuning after errors
+        ewgtsNeedTuning, //gestures are to be retuned upon next event
+        ewgtsTuned
+    };
+    eWinGestureTuneState winGestureTuneState;//See ViewerEventFilter::eventFilter function for explanation
 
 private:
     static void setViewportCB(void * userdata, SoAction * action);

src/Gui/WinNativeGestureRecognizers.cpp

@@ -41,6 +41,7 @@
 
 #include <qgesture.h>
 #include <private/qevent_p.h>
+#include <Base/Exception.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -188,10 +189,28 @@ void WinNativeGestureRecognizerPinch::reset(QGesture* gesture)
   q->fingerDistance = 0;
 }
 
+//function prototype for dymanic linking
+typedef BOOL ( __stdcall * ptrSetGestureConfig) (
+     HWND ,              // window for which configuration is specified
+     DWORD ,             // reserved, must be 0
+     UINT ,              // count of GESTURECONFIG structures
+     PGESTURECONFIG ,    // array of GESTURECONFIG structures, dwIDs will be processed in the
+                         // order specified and repeated occurances will overwrite previous ones
+     UINT );             // sizeof(GESTURECONFIG)
+
 void WinNativeGestureRecognizerPinch::TuneWindowsGestures(QWidget* target)
 {
     //modify windows-specific gesture options
 #if WINVER >= _WIN32_WINNT_WIN7
+    //dynamic linking - required to be able to run on windows pre-7
+    HINSTANCE hinstLib = LoadLibraryA("user32.dll");
+    if (hinstLib == 0)
+        throw Base::Exception("LoadLibrary(user32.dll) failed. Could not tune Windows gestures.");
+
+    ptrSetGestureConfig dllSetGestureConfig = reinterpret_cast<ptrSetGestureConfig> (GetProcAddress(hinstLib,"SetGestureConfig"));
+    if (dllSetGestureConfig == 0)
+        throw Base::Exception("DLL entry point for SetGestureConfig not found in user32.dll. Could not tune Windows gestures.");
+
     HWND w = target->winId();
 
     //fill in the options
@@ -205,10 +224,12 @@ void WinNativeGestureRecognizerPinch::TuneWindowsGestures(QWidget* target)
     cfgs[1].dwWant = GC_ROTATE;
 
     //set the options
-    bool ret = SetGestureConfig(w, 0, nCfg, cfgs, sizeof(GESTURECONFIG));
-    assert(ret); //if(!ret) throw
+    bool ret = dllSetGestureConfig(w, 0, nCfg, cfgs, sizeof(GESTURECONFIG));
+    assert(ret);
     if(!ret){
-        DWORD err = GetLastError();//for debugging
+        DWORD err = GetLastError();
+        QString errMsg = QString::fromLatin1("Error in SetGestureConfig. GetLastError = %1").arg(err);
+        throw Base::Exception(errMsg.toLatin1());
     }
 #endif
 }