[GTK4] Cleanup GtkEventControllerMotion Enter/Leave events

Support for mouse motion events was already implemented with
386bebd. However, following
edge cases were missed:

- Moving the cursor out of the shell and back in doesn't fire a "mouse
enter" event.

Similarly to the way motion events are handled in GTK3, the current
control needs to be cleared on a "leave" event. Otherwise the "enter"
event is suppressed when the cursor is moved out of and back in a shell
again.

- Moving from one widget to another fires two "mouse exit" events.

One event is fired by "gtk4_motion_event()", the other by "leaveProc()".
Only the former should be fired, as it contains the proper "x" and "y"
coordinates.

Latter is fired because "getCursorControl()" always returns "null". This
has been fixed by first calculating the GtkWindow from the GdkSurface
and then selecting the widget at the mouse coordinates. The whole
implementation has also been restructured so that the X11-based
heuristic via the XQueryPointer is only used for GTK3 (because it would
simply return early for GTK4 anyway).

- The tooltip window isn't moved when hovering over different widgets

This is because the tooltip is set for the shell, even though it should
be set for the individual widgets. As a result, only the text is updated
but the window remains where it was initially shown.

Closes #219

Author: ptziegler

bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/gtk4.c

@@ -1614,6 +1614,18 @@ JNIEXPORT jlong JNICALL GTK4_NATIVE(gtk_1named_1action_1new)
 }
 #endif
 
+#ifndef NO_gtk_1native_1get_1for_1surface
+JNIEXPORT jlong JNICALL GTK4_NATIVE(gtk_1native_1get_1for_1surface)
+	(JNIEnv *env, jclass that, jlong arg0)
+{
+	jlong rc = 0;
+	GTK4_NATIVE_ENTER(env, that, gtk_1native_1get_1for_1surface_FUNC);
+	rc = (jlong)gtk_native_get_for_surface((GdkSurface *)arg0);
+	GTK4_NATIVE_EXIT(env, that, gtk_1native_1get_1for_1surface_FUNC);
+	return rc;
+}
+#endif
+
 #ifndef NO_gtk_1native_1get_1surface
 JNIEXPORT jlong JNICALL GTK4_NATIVE(gtk_1native_1get_1surface)
 	(JNIEnv *env, jclass that, jlong arg0)
@@ -2178,6 +2190,18 @@ JNIEXPORT void JNICALL GTK4_NATIVE(gtk_1widget_1measure)
 }
 #endif
 
+#ifndef NO_gtk_1widget_1pick
+JNIEXPORT jlong JNICALL GTK4_NATIVE(gtk_1widget_1pick)
+	(JNIEnv *env, jclass that, jlong arg0, jdouble arg1, jdouble arg2, jint arg3)
+{
+	jlong rc = 0;
+	GTK4_NATIVE_ENTER(env, that, gtk_1widget_1pick_FUNC);
+	rc = (jlong)gtk_widget_pick((GtkWidget *)arg0, (double)arg1, (double)arg2, (GtkPickFlags)arg3);
+	GTK4_NATIVE_EXIT(env, that, gtk_1widget_1pick_FUNC);
+	return rc;
+}
+#endif
+
 #ifndef NO_gtk_1widget_1set_1cursor
 JNIEXPORT void JNICALL GTK4_NATIVE(gtk_1widget_1set_1cursor)
 	(JNIEnv *env, jclass that, jlong arg0, jlong arg1)

bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/gtk4_stats.h

@@ -135,6 +135,7 @@ typedef enum {
 	gtk_1label_1set_1wrap_1mode_FUNC,
 	gtk_1menu_1button_1set_1use_1underline_FUNC,
 	gtk_1named_1action_1new_FUNC,
+	gtk_1native_1get_1for_1surface_FUNC,
 	gtk_1native_1get_1surface_FUNC,
 	gtk_1picture_1new_FUNC,
 	gtk_1picture_1set_1can_1shrink_FUNC,
@@ -180,6 +181,7 @@ typedef enum {
 	gtk_1widget_1insert_1after_FUNC,
 	gtk_1widget_1insert_1before_FUNC,
 	gtk_1widget_1measure_FUNC,
+	gtk_1widget_1pick_FUNC,
 	gtk_1widget_1set_1cursor_FUNC,
 	gtk_1widget_1set_1focusable_FUNC,
 	gtk_1widget_1size_1allocate_FUNC,

bundles/org.eclipse.swt/Eclipse SWT PI/gtk/org/eclipse/swt/internal/gtk4/GTK4.java

@@ -26,6 +26,10 @@ public class GTK4 {
 	public static final int GTK_EVENT_SEQUENCE_CLAIMED = 1;
 	public static final int GTK_EVENT_SEQUENCE_DENIED = 2;
 
+	public static final int GTK_PICK_DEFAULT = 0;
+	public static final int GTK_PICK_INSENSITIVE = 1;
+	public static final int GTK_PICK_NON_TARGETABLE = 2;
+
 	/**
 	 * @param context cast=(GtkIMContext *)
 	 * @param event cast=(GdkEvent *)
@@ -130,6 +134,10 @@ public class GTK4 {
 	/* GTK Initialization */
 	public static final native boolean gtk_init_check();
 
+	/* GtkNative */
+	/** @param surface cast=(GdkSurface *) */
+	public static final native long gtk_native_get_for_surface(long surface);
+
 	/* GdkToplevel */
 	/** @param toplevel cast=(GdkToplevel *) */
 	public static final native int gdk_toplevel_get_state(long toplevel);
@@ -667,6 +675,13 @@ public class GTK4 {
 	 * @param next_sibling cast=(GtkWidget *)
 	 */
 	public static final native void gtk_widget_insert_before(long widget, long parent, long next_sibling);
+	/**
+	 * @param widget cast=(GtkWidget *)
+	 * @param x cast=(double)
+	 * @param y cast=(double)
+	 * @param flags cast=(GtkPickFlags)
+	 */
+	public static final native long gtk_widget_pick(long widget, double x, double y, int flags);
 
 	/* GtkComboBox */
 	/** @param combo_box cast=(GtkComboBox *) */

bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Control.java

@@ -3622,7 +3622,7 @@ void gtk4_enter_event(long controller, double x, double y, long event) {
 		char [] chars = fixMnemonic (toolTipText, false, true);
 		buffer = Converter.wcsToMbcs (chars, true);
 	}
-	long toolHandle = getShell().handle;
+	long toolHandle = handle;
 	GTK.gtk_widget_set_tooltip_text (toolHandle, buffer);
 
 	if (display.currentControl == this) return;
@@ -4044,6 +4044,7 @@ void gtk4_leave_event(long controller, long event) {
 
 	if (sendLeaveNotify() || display.getCursorControl() == null) {
 		sendMouseEvent(SWT.MouseExit, 0, 0, 0, 0, false, 0);
+		display.currentControl = null;
 	}
 }
 

bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Display.java

@@ -1900,46 +1900,48 @@ public Control getCursorControl () {
 		gdkResource = gdk_device_get_surface_at_position (xDouble, yDouble);
 		x[0] = (int) xDouble[0];
 		y[0] = (int) yDouble[0];
+		if (gdkResource != 0) {
+			long gtkWindow = GTK4.gtk_native_get_for_surface(gdkResource);
+			if (gtkWindow != 0) {
+				handle = GTK4.gtk_widget_pick(gtkWindow, xDouble[0], yDouble[0], GTK4.GTK_PICK_DEFAULT);
+			}
+		}
 	} else {
 		gdkResource = gdk_device_get_window_at_position (x,y);
-	}
-	if (gdkResource != 0) {
-		if (GTK.GTK4) {
-			// TODO: GTK4 need to retrieve handle
-		} else {
+		if (gdkResource != 0) {
 			GDK.gdk_window_get_user_data (gdkResource, user_data);
-		}
-		handle = user_data [0];
-	} else {
-		// Feature in GTK. The gdk_device_get_[surface/window]_at_position() functions will not return a
-		// surface/window if the pointer is over a foreign embedded window. The fix is to use XQueryPointer
-		// to find the containing GDK window (see bug 177368.)
-		// However embedding foreign windows is not supported by the Wayland backend for GTK3 and is not
-		// supported at all on GTK4, so skip the heuristic in these situations.
-		if (OS.isWayland() || GTK.GTK4) return null;
-		long gdkDisplay = GDK.gdk_display_get_default();
-		if (OS.isX11()) {
-			GDK.gdk_x11_display_error_trap_push(gdkDisplay);
-		}
-		int[] unusedInt = new int[1];
-		long [] unusedPtr = new long [1], buffer = new long [1];
-		long xWindow, xParent = OS.XDefaultRootWindow (xDisplay);
-		do {
-			if (OS.XQueryPointer (xDisplay, xParent, unusedPtr, buffer, unusedInt, unusedInt, unusedInt, unusedInt, unusedInt) == 0) {
-				handle = 0;
-				break;
+			handle = user_data [0];
+		} else {
+			// Feature in GTK. The gdk_device_get_[surface/window]_at_position() functions will not return a
+			// surface/window if the pointer is over a foreign embedded window. The fix is to use XQueryPointer
+			// to find the containing GDK window (see bug 177368.)
+			// However embedding foreign windows is not supported by the Wayland backend for GTK3 and is not
+			// supported at all on GTK4, so skip the heuristic in these situations.
+			if (OS.isWayland() || GTK.GTK4) return null;
+			long gdkDisplay = GDK.gdk_display_get_default();
+			if (OS.isX11()) {
+				GDK.gdk_x11_display_error_trap_push(gdkDisplay);
 			}
-			if ((xWindow = buffer [0]) != 0) {
-				xParent = xWindow;
-				long gdkWindow = GDK.gdk_x11_window_lookup_for_display(gdkDisplay, xWindow);
-				if (gdkWindow != 0)	{
-					GDK.gdk_window_get_user_data (gdkWindow, user_data);
-					if (user_data[0] != 0) handle = user_data[0];
+			int[] unusedInt = new int[1];
+			long [] unusedPtr = new long [1], buffer = new long [1];
+			long xWindow, xParent = OS.XDefaultRootWindow (xDisplay);
+			do {
+				if (OS.XQueryPointer (xDisplay, xParent, unusedPtr, buffer, unusedInt, unusedInt, unusedInt, unusedInt, unusedInt) == 0) {
+					handle = 0;
+					break;
+				}
+				if ((xWindow = buffer [0]) != 0) {
+					xParent = xWindow;
+					long gdkWindow = GDK.gdk_x11_window_lookup_for_display(gdkDisplay, xWindow);
+					if (gdkWindow != 0)	{
+						GDK.gdk_window_get_user_data (gdkWindow, user_data);
+						if (user_data[0] != 0) handle = user_data[0];
+					}
 				}
+			} while (xWindow != 0);
+			if (OS.isX11()) {
+				GDK.gdk_x11_display_error_trap_pop_ignored(gdkDisplay);
 			}
-		} while (xWindow != 0);
-		if (OS.isX11()) {
-			GDK.gdk_x11_display_error_trap_pop_ignored(gdkDisplay);
 		}
 	}
 	if (handle == 0) return null;