[win32] Encapsulate Font handle with win32_getHandle

The handle of Font is encapsulated and exposed only via static method
win32_getHandle and direct access to the field is replaced by access to
that method.

Author: ShahzaibIbrahim

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

@@ -46,9 +46,8 @@ public final class Font extends Resource {
 	 * platforms and should never be accessed from application code.
 	 * </p>
 	 *
-	 * @noreference This field is not intended to be referenced by clients.
 	 */
-	public long handle;
+	private long handle;
 
 	/**
 	 * The zoom in % of the standard resolution used for conversion of point height to pixel height
@@ -172,7 +171,8 @@ public Font(Device device, String name, int height, int style) {
 	super(device);
 	if (name == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
 	this.zoom = DPIUtil.getNativeDeviceZoom();
-	init(new FontData (name, height, style));
+	FontData fd = new FontData (name, height, style);
+	init(fd);
 	this.fontHeight = height;
 	init();
 }
@@ -181,7 +181,8 @@ public Font(Device device, String name, int height, int style) {
 	super(device);
 	if (name == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
 	this.zoom = DPIUtil.getNativeDeviceZoom();
-	init(new FontData (name, height, style));
+	FontData fd = new FontData (name, height, style);
+	init(fd);
 	this.fontHeight = height;
 	init();
 }
@@ -285,6 +286,23 @@ public String toString () {
 	return "Font {" + handle + "}";
 }
 
+/**
+ * Creates or returns a handle for the requested font.
+ * <p>
+ * <b>IMPORTANT:</b> This method is not part of the public API for
+ * <code>Font</code>. It is marked public only so that it can be shared within
+ * the packages provided by SWT. It is not available on all platforms, and
+ * should never be called from application code.
+ *
+ * @param font the font to get the handle of
+ * @return handle of the font
+ *
+ * @noreference This method is not intended to be referenced by clients.
+ */
+public static long win32_getHandle(Font font) {
+	return font.handle;
+}
+
 /**
  * Invokes platform specific functionality to allocate a new font.
  * <p>

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/internal/SWTFontProvider.java

@@ -48,7 +48,7 @@ public static Font getSystemFont(Device device, int zoom) {
 	}
 
 	public static long getSystemFontHandle(Device device, int zoom) {
-		return getSystemFont(device, zoom).handle;
+		return Font.win32_getHandle(getSystemFont(device, zoom));
 	}
 
 	/**
@@ -67,14 +67,14 @@ public static Font getFont(Device device, FontData fontData, int zoom) {
 	}
 
 	public static long getFontHandle(Device device, FontData fontData, int zoom) {
-		return getFont(device, fontData, zoom).handle;
+		return Font.win32_getHandle(getFont(device, fontData, zoom));
 	}
 
 	public static long getFontHandle(Font font, int zoom) {
 		if (font == null) {
 			SWT.error(SWT.ERROR_NULL_ARGUMENT);
 		}
-		return getFont(font.getDevice(), font.getFontData()[0], zoom).handle;
+		return Font.win32_getHandle(getFont(font.getDevice(), font.getFontData()[0], zoom));
 	}
 
 	/**

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/internal/ScalingSWTFontRegistry.java

@@ -44,7 +44,7 @@ private Font getScaledFont(int zoom) {
 
 		private Font createAndCacheFont(int zoom) {
 			Font newFont = createFont(zoom);
-			customFontHandlesKeyMap.put(newFont.handle, this);
+			customFontHandlesKeyMap.put(Font.win32_getHandle(newFont), this);
 			scaledFonts.put(zoom, newFont);
 			return newFont;
 		}

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

@@ -3439,7 +3439,7 @@ public void setFont (Font font) {
 	long hFont = 0;
 	if (newFont != null) {
 		if (newFont.isDisposed()) error(SWT.ERROR_INVALID_ARGUMENT);
-		hFont = newFont.handle;
+		hFont = Font.win32_getHandle(newFont);
 	}
 	this.font = newFont;
 	if (hFont == 0) hFont = defaultFont ();