When computing the size of a widget always return values rounded up

When converting pixels to point there can be depending on the zoom level
be a fractional result.
Currently in all cases these result is converted into an integer using
`Math.round()` that will make values `+/-0.5` resulting in small values
to be round towards a smaller value.

While it is maybe valid for a _location_, when using points to express a
_dimension_ this is not okay as it will result in the reported (integer)
value to be to small leading to errors when the SWT API is then used
after performing additional computations maybe.

See
- eclipse-platform#2381
- eclipse-platform#2166

Author: ShahzaibIbrahim

bundles/org.eclipse.swt/Eclipse SWT AWT/win32/org/eclipse/swt/awt/SWT_AWT.java

@@ -293,7 +293,7 @@ public void componentResized (ComponentEvent e) {
 			display.syncExec (() -> {
 				if (shell.isDisposed()) return;
 				Dimension dim = parent.getSize ();
-				shell.setSize(Win32DPIUtils.pixelToPoint(new Point(dim.width, dim.height), DPIUtil.getDeviceZoom())); // To Points
+				shell.setSize(Win32DPIUtils.pixelToPointAsSize(new Point(dim.width, dim.height), DPIUtil.getDeviceZoom())); // To Points
 			});
 		}
 	};

bundles/org.eclipse.swt/Eclipse SWT Browser/win32/org/eclipse/swt/browser/IE.java

@@ -1880,7 +1880,7 @@ void handleDOMEvent (OleEvent e) {
 	int screenY = pVarResult.getInt();
 	pVarResult.dispose();
 
-	Point position = Win32DPIUtils.pixelToPoint(new Point(screenX, screenY), DPIUtil.getDeviceZoom()); // To Points
+	Point position = Win32DPIUtils.pixelToPointAsLocation(new Point(screenX, screenY), DPIUtil.getDeviceZoom()); // To Points
 	position = browser.getDisplay().map(null, browser, position);
 	newEvent.x = position.x; newEvent.y = position.y;
 

bundles/org.eclipse.swt/Eclipse SWT Drag and Drop/win32/org/eclipse/swt/dnd/DropTarget.java

@@ -410,7 +410,7 @@ private Point convertPixelToPoint(int xInPixels, int yInPixels) {
 	if (this.control == null) {
 		// If there is no control for context, the behavior remains as before
 		int zoom = DPIUtil.getZoomForAutoscaleProperty(this.nativeZoom);
-		return Win32DPIUtils.pixelToPoint(new Point(xInPixels, yInPixels), zoom);
+		return Win32DPIUtils.pixelToPointAsLocation(new Point(xInPixels, yInPixels), zoom);
 	}
 	int zoom = DPIUtil.getZoomForAutoscaleProperty(this.control.nativeZoom);
 	// There is no API to convert absolute values in pixels to display relative
@@ -419,7 +419,7 @@ private Point convertPixelToPoint(int xInPixels, int yInPixels) {
 	POINT pt = new POINT ();
 	pt.x = xInPixels;  pt.y = yInPixels;
 	OS.ScreenToClient (this.control.handle, pt);
-	Point p = Win32DPIUtils.pixelToPoint(new Point (pt.x, pt.y), zoom);
+	Point p = Win32DPIUtils.pixelToPointAsLocation(new Point (pt.x, pt.y), zoom);
 	return this.control.toDisplay(p);
 }
 

bundles/org.eclipse.swt/Eclipse SWT Drag and Drop/win32/org/eclipse/swt/dnd/TableDropTargetEffect.java

@@ -151,7 +151,7 @@ public void dragOver(DropTargetEvent event) {
 		int effect = checkEffect(event.feedback);
 		long handle = table.handle;
 		Point coordinates = new Point(event.x, event.y);
-		coordinates = Win32DPIUtils.pointToPixel(table.toControl(coordinates), DPIUtil.getZoomForAutoscaleProperty(table.nativeZoom)); // To Pixels
+		coordinates = Win32DPIUtils.pointToPixelAsLocation(table.toControl(coordinates), DPIUtil.getZoomForAutoscaleProperty(table.nativeZoom)); // To Pixels
 		LVHITTESTINFO pinfo = new LVHITTESTINFO();
 		pinfo.x = coordinates.x;
 		pinfo.y = coordinates.y;

bundles/org.eclipse.swt/Eclipse SWT Drag and Drop/win32/org/eclipse/swt/dnd/TreeDropTargetEffect.java

@@ -165,7 +165,7 @@ public void dragOver(DropTargetEvent event) {
 		int effect = checkEffect(event.feedback);
 		long handle = tree.handle;
 		Point coordinates = new Point(event.x, event.y);
-		coordinates = Win32DPIUtils.pointToPixel(tree.toControl(coordinates), DPIUtil.getZoomForAutoscaleProperty(tree.nativeZoom)); // To Pixels
+		coordinates = Win32DPIUtils.pointToPixelAsLocation(tree.toControl(coordinates), DPIUtil.getZoomForAutoscaleProperty(tree.nativeZoom)); // To Pixels
 		TVHITTESTINFO lpht = new TVHITTESTINFO ();
 		lpht.x = coordinates.x;
 		lpht.y = coordinates.y;

bundles/org.eclipse.swt/Eclipse SWT OLE Win32/win32/org/eclipse/swt/ole/win32/OleClientSite.java

@@ -987,7 +987,7 @@ private int OnInPlaceDeactivate() {
 	return COM.S_OK;
 }
 private int OnPosRectChange(long lprcPosRect) {
-	Point size = Win32DPIUtils.pointToPixel(getSize(), DPIUtil.getZoomForAutoscaleProperty(nativeZoom)); // To Pixels
+	Point size = Win32DPIUtils.pointToPixelAsSize(getSize(), DPIUtil.getZoomForAutoscaleProperty(nativeZoom)); // To Pixels
 	setExtent(size.x, size.y);
 	return COM.S_OK;
 }

bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/graphics/Point.java

@@ -139,13 +139,20 @@ public static sealed class OfFloat extends Point permits Point.WithMonitor {
 	private static final long serialVersionUID = -1862062276431597053L;
 
 	public float residualX, residualY;
+	private final RoundingMode roundingMode;
 
 	public OfFloat(int x, int y) {
 		super(x, y);
+		this.roundingMode = null;
 	}
 
 	public OfFloat(float x, float y) {
-		super(Math.round(x), Math.round(y));
+		this(x, y, RoundingMode.ROUND);
+	}
+
+	public OfFloat(float x, float y, RoundingMode roundingMode) {
+		super(roundingMode.round(x), roundingMode.round(y));
+		this.roundingMode = roundingMode;
 		this.residualX = x - this.x;
 		this.residualY = y - this.y;
 	}
@@ -159,12 +166,12 @@ public float getY() {
 	}
 
 	public void setX(float x) {
-		this.x = Math.round(x);
+		this.x = roundingMode.round(x);
 		this.residualX = x - this.x;
 	}
 
 	public void setY(float y) {
-		this.y = Math.round(y);
+		this.y = roundingMode.round(y);
 		this.residualY = y - this.y;
 	}
 

bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/graphics/RoundingMode.java

@@ -0,0 +1,17 @@
+package org.eclipse.swt.graphics;
+/**
+* @noreference This class is not intended to be referenced by clients
+*/
+public enum RoundingMode {
+ ROUND, UP;
+
+public int round(float x) {
+	if (this == ROUND) {
+		return Math.round(x);
+	}
+	if (this == UP) {
+		return (int) Math.ceil(x);
+	}
+	return (int) x;
+}
+}

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/Device.java

@@ -526,7 +526,7 @@ public Point getDPI () {
 	int dpiX = OS.GetDeviceCaps (hDC, OS.LOGPIXELSX);
 	int dpiY = OS.GetDeviceCaps (hDC, OS.LOGPIXELSY);
 	internal_dispose_GC (hDC, null);
-	return Win32DPIUtils.pixelToPoint(new Point (dpiX, dpiY), DPIUtil.getZoomForAutoscaleProperty(getDeviceZoom()));
+	return Win32DPIUtils.pixelToPointAsLocation(new Point (dpiX, dpiY), DPIUtil.getZoomForAutoscaleProperty(getDeviceZoom()));
 }
 
 /**

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/GC.java

@@ -1056,7 +1056,7 @@ private class DrawImageOperation extends ImageOperation {
 
 	@Override
 	void apply() {
-		drawImageInPixels(getImage(), Win32DPIUtils.pointToPixel(drawable, this.location, getZoom()));
+		drawImageInPixels(getImage(), Win32DPIUtils.pointToPixelAsLocation(drawable, this.location, getZoom()));
 	}
 
 	private void drawImageInPixels(Image image, Point location) {
@@ -1868,8 +1868,8 @@ private class DrawLineOperation extends Operation {
 	@Override
 	void apply() {
 		int deviceZoom = getZoom();
-		Point startInPixels = Win32DPIUtils.pointToPixel (drawable, start, deviceZoom);
-		Point endInPixels = Win32DPIUtils.pointToPixel (drawable, end, deviceZoom);
+		Point startInPixels = Win32DPIUtils.pointToPixelAsLocation (drawable, start, deviceZoom);
+		Point endInPixels = Win32DPIUtils.pointToPixelAsLocation (drawable, end, deviceZoom);
 		drawLineInPixels(startInPixels.x, startInPixels.y, endInPixels.x, endInPixels.y);
 	}
 }
@@ -2039,7 +2039,7 @@ private class DrawPointOperation extends Operation {
 
 	@Override
 	void apply() {
-		Point scaleUpLocation = Win32DPIUtils.pointToPixel(location, getZoom());
+		Point scaleUpLocation = Win32DPIUtils.pointToPixelAsLocation(location, getZoom());
 		drawPointInPixels(scaleUpLocation.x, scaleUpLocation.y);
 	}
 }
@@ -2457,7 +2457,7 @@ private class DrawStringOperation extends Operation {
 
 	@Override
 	void apply() {
-		Point scaledLocation = Win32DPIUtils.pointToPixel(drawable, location, getZoom());
+		Point scaledLocation = Win32DPIUtils.pointToPixelAsLocation(drawable, location, getZoom());
 		drawStringInPixels(string, scaledLocation.x, scaledLocation.y, isTransparent);
 	}
 }
@@ -2643,7 +2643,7 @@ private class DrawTextOperation extends Operation {
 
 	@Override
 	void apply() {
-		Point scaledLocation = Win32DPIUtils.pointToPixel(drawable, location, getZoom());
+		Point scaledLocation = Win32DPIUtils.pointToPixelAsLocation(drawable, location, getZoom());
 		drawTextInPixels(string, scaledLocation.x, scaledLocation.y, flags);
 	}
 }
@@ -5736,7 +5736,7 @@ void apply() {
  */
 public Point stringExtent (String string) {
 	if (string == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
-	return Win32DPIUtils.pixelToPoint(drawable, stringExtentInPixels(string), getZoom());
+	return Win32DPIUtils.pixelToPointAsSize(drawable, stringExtentInPixels(string), getZoom());
 }
 
 Point stringExtentInPixels (String string) {
@@ -5781,7 +5781,7 @@ Point stringExtentInPixels (String string) {
  * </ul>
  */
 public Point textExtent (String string) {
-	return Win32DPIUtils.pixelToPoint(drawable, textExtentInPixels(string, SWT.DRAW_DELIMITER | SWT.DRAW_TAB), getZoom());
+	return Win32DPIUtils.pixelToPointAsSize(drawable, textExtentInPixels(string, SWT.DRAW_DELIMITER | SWT.DRAW_TAB), getZoom());
 }
 
 /**
@@ -5816,7 +5816,7 @@ public Point textExtent (String string) {
  * </ul>
  */
 public Point textExtent (String string, int flags) {
-	return Win32DPIUtils.pixelToPoint(drawable, textExtentInPixels(string, flags), getZoom());
+	return Win32DPIUtils.pixelToPointAsSize(drawable, textExtentInPixels(string, flags), getZoom());
 }
 
 Point textExtentInPixels(String string, int flags) {