Bug 1348: X11 XI Multitouch: Fixes of previous commit 92006e4baef57f1f3fb647dd307aed5989fd4c8d

Previous commit 92006e4baef57f1f3fb647dd307aed5989fd4c8d

(Note to Danny: I cannot test this now - please re-test and/or review)

X11Common::JavaWindow
- Owns XI extension's xiOpcode, selected xiTouchDeviceId and tracked XITouchPosition array

X11Window::CreateWindow
- Query XI extension only once @ window creation and earmark xiOpcode in JavaWindow instance

- Fix: Device selection code was "class->type != XITouchClass",
  but shouldn't it be 'XITouchClass == class->type' (as patched here)

- Fix: Free XIQueryDevice returned XIDeviceInfo array via XIFreeDeviceInfo

- Earmark deviceid in JavaWindow instance

X11Display
- Moved global static touch_coordinates to JavaWindow::xiTouchCoords instance

X11Display::DispatchMessage
- Changed event handling structure similar to https://keithp.com/blogs/Cursor_tracking/

- Fix: Free XGetEventData's optional memory allocation via XFreeEventData

- Reuse JavaWindow's queried xiOpcode

- Fix: Don't overrise windowPointer, instead validate and require a match. JavaWindow must match!

- Fix: Also validate chosen deviceid with JavaWindow's registered device

Newt Build:
- Added libXi in build recipe and doc

1 files changed, 49 insertions, 37 deletions

diff --git a/src/newt/native/X11Window.c b/src/newt/native/X11Window.c
index 7208b205a..8fb3ecbb9 100644
--- a/src/newt/native/X11Window.c
+++ b/src/newt/native/X11Window.c
@@ -953,47 +953,59 @@ JNIEXPORT jlongArray JNICALL Java_jogamp_newt_driver_x11_WindowDriver_CreateWind
         }
     }
     
+    // Register X11 Multitouch Events for new Window
+    // https://www.x.org/wiki/Development/Documentation/Multitouch/
     {
-      XIDeviceInfo *di;
-      XIDeviceInfo *dev;
-      XITouchClassInfo *class;
-      int devid = -1;
+        int xi_opcode, event, error;
+
+        javaWindow->xiTouchDeviceId = -1;
+
+        if( XQueryExtension(dpy, "XInputExtension", &xi_opcode, &event, &error) ) {
+            XIDeviceInfo *di;
+            int devid = -1;
+            int cnt = 0;
+
+            javaWindow->xiOpcode = xi_opcode;
+            di = XIQueryDevice(dpy, XIAllDevices, &cnt);
+
+            if( NULL != di && 0 < cnt ) {
+                XIDeviceInfo *dev;
+                int i, j;
       
-      int cnt;
-      int i, j;
-
-      di = XIQueryDevice(dpy, XIAllDevices, &cnt);
-      for (i = 0; i < cnt; i ++)
-      {
-        dev = &di[i];
-        for (j = 0; j < dev->num_classes; j ++)
-        {
-          class = (XITouchClassInfo*)(dev->classes[j]);
-          if (class->type != XITouchClass)
-          {
-            devid = dev->deviceid;
-            break;
-          }
-        }
-        if(devid != -1)
-        {
-          break;
-        }
-      }
+                // find the 1st XITouchClass device available
+                for (i = 0; i < cnt && -1 == devid; i ++) {
+                    dev = &di[i];
+                    for (j = 0; j < dev->num_classes; j ++) {
+                        XITouchClassInfo *class = (XITouchClassInfo*)(dev->classes[j]);
+                        if ( XITouchClass == class->type ) {
+                          devid = dev->deviceid;
+                          break;
+                        }
+                    }
+                }
+                XIFreeDeviceInfo(di);
+                di = NULL;
+                
+                if( -1 != devid ) {
+                    // register 1st XITouchClass device if available
+                    XIEventMask mask = {
+                      .deviceid = devid,
+                      .mask_len = XIMaskLen(XI_TouchEnd) // in bytes
+                    };
+                    
+                    mask.mask = (unsigned char*)calloc(mask.mask_len, sizeof(unsigned char));
+                    XISetMask(mask.mask, XI_TouchBegin);
+                    XISetMask(mask.mask, XI_TouchUpdate);
+                    XISetMask(mask.mask, XI_TouchEnd);
       
-      XIEventMask mask = {
-        .deviceid = devid, //XIAllDevices,
-        .mask_len = XIMaskLen(XI_TouchEnd)
-      };
+                    XISelectEvents(dpy, window, &mask, 1);
       
-      mask.mask = (unsigned char*)calloc(3, sizeof(char));
-      XISetMask(mask.mask, XI_TouchBegin);
-      XISetMask(mask.mask, XI_TouchUpdate);
-      XISetMask(mask.mask, XI_TouchEnd);
-
-      XISelectEvents(dpy, window, &mask, 1);
-
-      free(mask.mask);      
+                    free(mask.mask);      
+      
+                    javaWindow->xiTouchDeviceId = devid;
+                }
+            }
+        }
     }
     
     XFlush(dpy);