Ensure sendMeasureItemEvent is only called for OS.TTN_SHOW or custom

tooltips

Prior to PR #2241, sendMeasureItemEvent was only invoked when the
tooltip was not a CustomTooltip. However, after that change,
sendMeasureItemEvent is now called for all tooltips.

This results in an unintended side effect: sendMeasureItemEvent compares
the item's width(obtained from TableItem.getBounds()) to the width of column (via OS.LVM_GETCOLUMNWIDTH) it is present in and sometimes
concludes incorrectly that the item doesn't fit. This causes an
unnecessary scrollbar to appear, even though the item is fully contained
within the column.

While the root cause lies in how column item width is calculated (which
should be addressed separately), this change acts as a temporary fix to
prevent scrollbars from appearing erroneously particularly in the
MultipleHyperlinkPresenter.

This workaround aligns with the original behavior prior to PR #2241 as
sendMeasureItemEvent would not be called for non customToolTip and
restores expected UI behavior for now.

Author: arunjose696

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Table.java

@@ -7188,23 +7188,21 @@ private LRESULT positionTooltip(NMHDR hdr, long lParam) {
 		if (newFont != 0) oldFont = OS.SelectObject (hDC, newFont);
 		long hFont = item.fontHandle (pinfo.iSubItem);
 		if (hFont != -1) hFont = OS.SelectObject (hDC, hFont);
-		Event event = sendMeasureItemEvent (item, pinfo.iItem, pinfo.iSubItem, hDC);
-		if (!isDisposed () && !item.isDisposed ()) {
-			RECT itemRect = new RECT ();
-			Rectangle boundsInPixels = Win32DPIUtils.pointToPixel(event.getBounds(), getZoom());
-			OS.SetRect (itemRect, boundsInPixels.x, boundsInPixels.y, boundsInPixels.x + boundsInPixels.width, boundsInPixels.y + boundsInPixels.height);
+		if (!isDisposed() && !item.isDisposed()) {
 			if (hdr.code == OS.TTN_SHOW) {
-				RECT toolRect = isCustomToolTip() ? toolTipRect (itemRect) : itemRect;
-				OS.MapWindowPoints (handle, 0, toolRect, 2);
-				long hwndToolTip = OS.SendMessage (handle, OS.LVM_GETTOOLTIPS, 0, 0);
+				RECT itemRect = getItemBounds(pinfo, item, hDC);
+				RECT toolRect = isCustomToolTip() ? toolTipRect(itemRect) : itemRect;
+				OS.MapWindowPoints(handle, 0, toolRect, 2);
+				long hwndToolTip = OS.SendMessage(handle, OS.LVM_GETTOOLTIPS, 0, 0);
 				int flags = OS.SWP_NOACTIVATE | OS.SWP_NOZORDER;
 				Rectangle adjustedTooltipBounds = getDisplay().fitRectangleBoundsIntoMonitorWithCursor(toolRect);
 				OS.SetWindowPos(hwndToolTip, 0, adjustedTooltipBounds.x, adjustedTooltipBounds.y,
 						adjustedTooltipBounds.width, adjustedTooltipBounds.height, flags);
 				result = LRESULT.ONE;
 			} else if (isCustomToolTip()) {
-				NMTTDISPINFO lpnmtdi = new NMTTDISPINFO ();
-				OS.MoveMemory (lpnmtdi, lParam, NMTTDISPINFO.sizeof);
+				RECT itemRect = getItemBounds(pinfo, item, hDC);
+				NMTTDISPINFO lpnmtdi = new NMTTDISPINFO();
+				OS.MoveMemory(lpnmtdi, lParam, NMTTDISPINFO.sizeof);
 				if (lpnmtdi.lpszText != 0) {
 					OS.MoveMemory (lpnmtdi.lpszText, new char [1], 2);
 					OS.MoveMemory (lParam, lpnmtdi, NMTTDISPINFO.sizeof);
@@ -7231,6 +7229,15 @@ private LRESULT positionTooltip(NMHDR hdr, long lParam) {
 	return result;
 }
 
+private RECT getItemBounds(LVHITTESTINFO pinfo, TableItem item, long hDC) {
+	Event event = sendMeasureItemEvent(item, pinfo.iItem, pinfo.iSubItem, hDC);
+	RECT itemRect = new RECT();
+	Rectangle boundsInPixels = Win32DPIUtils.pointToPixel(event.getBounds(), getZoom());
+	OS.SetRect(itemRect, boundsInPixels.x, boundsInPixels.y, boundsInPixels.x + boundsInPixels.width,
+			boundsInPixels.y + boundsInPixels.height);
+	return itemRect;
+}
+
 LRESULT wmNotifyToolTip (NMTTCUSTOMDRAW nmcd, long lParam) {
 	switch (nmcd.dwDrawStage) {
 		case OS.CDDS_PREPAINT: {