diff --git a/pdf-over-gui/src/main/java/at/asit/pdfover/gui/composites/PositioningComposite.java b/pdf-over-gui/src/main/java/at/asit/pdfover/gui/composites/PositioningComposite.java
index d998c996..d9125e99 100644
--- a/pdf-over-gui/src/main/java/at/asit/pdfover/gui/composites/PositioningComposite.java
+++ b/pdf-over-gui/src/main/java/at/asit/pdfover/gui/composites/PositioningComposite.java
@@ -16,24 +16,18 @@
 package at.asit.pdfover.gui.composites;
 
 // Imports
-import java.awt.BorderLayout;
-import java.awt.Color;
-import java.awt.EventQueue;
-import java.awt.Frame;
-import java.awt.Image;
-import java.awt.event.KeyAdapter;
-import java.awt.event.KeyEvent;
-import java.awt.event.KeyListener;
-import java.awt.event.MouseWheelEvent;
-import java.awt.event.MouseWheelListener;
 import java.awt.geom.Point2D;
 
 import org.apache.pdfbox.pdmodel.PDDocument;
 import org.eclipse.swt.SWT;
-import org.eclipse.swt.awt.SWT_AWT;
+import org.eclipse.swt.events.KeyAdapter;
+import org.eclipse.swt.events.KeyEvent;
+import org.eclipse.swt.graphics.ImageData;
 import org.eclipse.swt.layout.FormLayout;
 import org.eclipse.swt.widgets.Button;
 import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Display;
+import org.eclipse.swt.widgets.Event;
 import org.eclipse.swt.widgets.Label;
 import org.eclipse.swt.widgets.ScrollBar;
 
@@ -41,7 +35,6 @@
 import at.asit.pdfover.gui.utils.SWTUtils;
 import at.asit.pdfover.gui.workflow.states.State;
 import at.asit.pdfover.signer.SignaturePosition;
-import lombok.extern.slf4j.Slf4j;
 
 /**
  * Composite which allows to position the signature on a preview of the document
@@ -49,12 +42,14 @@
 public class PositioningComposite extends StateComposite {
 
 	SignaturePanel viewer = null;
-	Frame frame = null;
 	Composite mainArea = null;
 	Composite bottomBar = null;
 	Button btnNewPage = null;
 	Label lblPage = null;
 	ScrollBar scrollbar = null;
+	private final Display display;
+	private static final int MOUSE_WHEEL_PAGE_THRESHOLD = 3;
+	private int mouseWheelAccumulator = 0;
 
 	private SignaturePosition position = null;
 	int currentPage = 0;
@@ -69,6 +64,7 @@ public class PositioningComposite extends StateComposite {
 	 */
 	public PositioningComposite(Composite parent, int style, State state) {
 		super(parent, style, state);
+		this.display = getDisplay();
 		this.setLayout(new FormLayout());
 
 		this.bottomBar = new Composite(this, SWT.NONE);
@@ -85,20 +81,20 @@ public PositioningComposite(Composite parent, int style, State state) {
 		this.lblPage = new Label(this.bottomBar, SWT.CENTER);
 		SWTUtils.anchor(lblPage).left(0).right(btnNewPage, 5).bottom(100);
 
-		this.mainArea = new Composite(this, SWT.EMBEDDED | SWT.V_SCROLL);
+		this.mainArea = new Composite(this, SWT.V_SCROLL);
 		SWTUtils.anchor(mainArea).left(0).right(100).top(0).bottom(bottomBar, -5);
+		this.mainArea.setLayout(new FormLayout());
 		this.scrollbar = this.mainArea.getVerticalBar();
 
-		this.frame = SWT_AWT.new_Frame(this.mainArea);
-		this.frame.addKeyListener(this.keyListener);
-		this.frame.addMouseWheelListener(this.mouseListener);
-
-		this.viewer = new SignaturePanel();
-		this.viewer.setSignaturePlaceholderBorderColor(new Color(
-				Constants.MAINBAR_ACTIVE_BACK_DARK.getRed(),
-				Constants.MAINBAR_ACTIVE_BACK_DARK.getGreen(),
-				Constants.MAINBAR_ACTIVE_BACK_DARK.getBlue()));
-		this.frame.add(this.viewer, BorderLayout.CENTER);
+		this.viewer = new SignaturePanel(this.mainArea, SWT.NONE);
+		SWTUtils.anchor(viewer).left(0).right(100).top(0).bottom(100);
+		this.viewer.setSignaturePlaceholderBorderColor(Constants.MAINBAR_ACTIVE_BACK_DARK);
+		this.viewer.setSignaturePositionAvailableCallback(() -> {
+			if (!isDisposed() && !this.btnSign.isDisposed())
+				this.btnSign.setEnabled(true);
+		});
+		this.viewer.addKeyListener(this.keyListener);
+		this.viewer.addListener(SWT.MouseVerticalWheel, this::handleMouseWheel);
 
 		SWTUtils.addSelectionListener(btnNewPage, () -> {
 			if (this.currentPage > this.numPages)
@@ -125,10 +121,7 @@ public PositioningComposite(Composite parent, int style, State state) {
 	 *            document to display
 	 */
 	public void displayDocument(final PDDocument document) {
-		EventQueue.invokeLater(() -> {
-			this.viewer.setDocument(document);
-			getDisplay().asyncExec(() -> this.btnSign.setEnabled(true));
-		});
+		this.viewer.setDocument(document);
 
 		if (document != null)
 		{
@@ -138,9 +131,14 @@ public void displayDocument(final PDDocument document) {
 		}
 	}
 
+	public void clearDocument() {
+		if (this.viewer != null && !this.viewer.isDisposed())
+			this.viewer.setDocument(null);
+	}
+
 	@Override
 	public void dispose() {
-		this.viewer.setDocument(null);
+		clearDocument();
 		super.dispose();
 	}
 
@@ -148,16 +146,13 @@ public void dispose() {
 	 * Request focus (to enable keyboard input)
 	 */
 	public void requestFocus() {
-		getDisplay().asyncExec(() -> {
+		if (this.display.isDisposed())
+			return;
+		this.display.asyncExec(() -> {
 			if (!this.isDisposed() && !this.mainArea.isDisposed()) {
 				this.mainArea.setFocus();
-				EventQueue.invokeLater(() -> {
-					if (!this.isDisposed()) {
-						if (!this.frame.hasFocus()) {
-							this.frame.requestFocus();
-						}
-					}
-				});
+				if (!this.viewer.isDisposed())
+					this.viewer.setFocus();
 			}
 		});
 	}
@@ -173,61 +168,63 @@ public void requestFocus() {
 	 * @param height
 	 *            height of the placeholder in page space
 	 */
-	public void setPlaceholder(final Image placeholder) {
-		EventQueue.invokeLater(() -> {
+	public void setPlaceholder(final ImageData placeholder) {
+		if (this.display.isDisposed())
+			return;
+		this.display.asyncExec(() -> {
+			if (isDisposed())
+				return;
 			if (this.viewer == null)
 				return;
 			this.viewer.setSignaturePlaceholder(placeholder);
 		});
 	}
 
-	KeyListener keyListener = new KeyAdapter() {
+	private KeyAdapter keyListener = new KeyAdapter() {
 		@Override
 		public void keyPressed(KeyEvent e) {
 			int newPage = PositioningComposite.this.currentPage;
 			int sigXOffset = 0;
 			int sigYOffset = 0;
 
-			switch (e.getKeyCode()) {
-			case KeyEvent.VK_PAGE_DOWN:
+			switch (e.keyCode) {
+			case SWT.PAGE_DOWN:
 				if (PositioningComposite.this.currentPage < PositioningComposite.this.numPages)
 					++newPage;
 				break;
 
-			case KeyEvent.VK_PAGE_UP:
+			case SWT.PAGE_UP:
 				if (PositioningComposite.this.currentPage > 1)
 					--newPage;
 				break;
 
-			case KeyEvent.VK_END:
+			case SWT.END:
 				newPage = PositioningComposite.this.numPages;
 				break;
 
-			case KeyEvent.VK_HOME:
+			case SWT.HOME:
 				newPage = 1;
 				break;
 
-			case KeyEvent.VK_ENTER:
+			case SWT.CR:
+			case SWT.KEYPAD_CR:
+				e.doit = false;
 				setFinalPosition();
 				break;
 
-			case KeyEvent.VK_LEFT:
-			case KeyEvent.VK_KP_LEFT:
+			case SWT.ARROW_LEFT:
 				sigXOffset -= Constants.SIGNATURE_KEYBOARD_POSITIONING_OFFSET;
 				break;
 
-			case KeyEvent.VK_RIGHT:
-			case KeyEvent.VK_KP_RIGHT:
+			case SWT.ARROW_RIGHT:
 				sigXOffset += Constants.SIGNATURE_KEYBOARD_POSITIONING_OFFSET;
 				break;
 
-			case KeyEvent.VK_UP:
-			case KeyEvent.VK_KP_UP:
+			case SWT.ARROW_UP:
 				sigYOffset += Constants.SIGNATURE_KEYBOARD_POSITIONING_OFFSET;
 				break;
 
-			case KeyEvent.VK_DOWN:
-			case KeyEvent.VK_KP_DOWN:
+			case SWT.ARROW_DOWN:
 				sigYOffset -= Constants.SIGNATURE_KEYBOARD_POSITIONING_OFFSET;
 				break;
 			}
@@ -240,37 +237,33 @@ public void keyPressed(KeyEvent e) {
 		}
 	};
 
-	MouseWheelListener mouseListener = new MouseWheelListener() {
-		private long lastEventTime = 0;
+	private void handleMouseWheel(Event e) {
+		e.doit = false;
 
-		@Override
-		public void mouseWheelMoved(MouseWheelEvent e) {
-			e.consume();
-			// Workaround for Linux: Events fire twice
-			if (e.getWhen() == this.lastEventTime)
-				return;
-			this.lastEventTime = e.getWhen();
-
-			int change = e.isShiftDown() ? 5 : 1;
-			int newPage = PositioningComposite.this.currentPage;
+		int change = (e.stateMask & SWT.SHIFT) != 0 ? 5 : 1;
+		int newPage = PositioningComposite.this.currentPage;
+		this.mouseWheelAccumulator += e.count;
 
-			if (e.getWheelRotation() < 0) {
-				newPage = Math.max(1, newPage - change);
-			} else if (e.getWheelRotation() > 0) {
-				newPage = Math.min(newPage + change, PositioningComposite.this.numPages);
-			}
-
-			if (newPage != PositioningComposite.this.currentPage)
-				showPage(newPage);
+		if (this.mouseWheelAccumulator >= MOUSE_WHEEL_PAGE_THRESHOLD) {
+			newPage = Math.max(1, newPage - change);
+			this.mouseWheelAccumulator = 0;
+		} else if (this.mouseWheelAccumulator <= -MOUSE_WHEEL_PAGE_THRESHOLD) {
+			newPage = Math.min(newPage + change, PositioningComposite.this.numPages);
+			this.mouseWheelAccumulator = 0;
 		}
-	};
+
+		if (newPage != PositioningComposite.this.currentPage)
+			showPage(newPage);
+	}
 
 	private Button btnSign;
 
 	void showPage(final int page) {
 		final int previousPage = this.currentPage;
 		this.currentPage = page;
-		getDisplay().asyncExec(() -> {
+		if (this.display.isDisposed())
+			return;
+		this.display.asyncExec(() -> {
 			int currentPage = this.currentPage;
 			int numPages = this.numPages;
 			if ((previousPage > numPages) && (currentPage <= numPages)) {
@@ -289,9 +282,7 @@ void showPage(final int page) {
 			this.scrollbar.setSelection(currentPage);
 			SWTUtils.setLocalizedText(lblPage, "positioning.page", currentPage, numPages);
 		});
-		EventQueue.invokeLater(() -> {
-			PositioningComposite.this.viewer.showPage(page);
-		});
+		PositioningComposite.this.viewer.showPage(page);
 	}
 
 	/**
@@ -303,9 +294,7 @@ void showPage(final int page) {
 	 *            signature placeholder vertical position offset (negative is down)
 	 */
 	public void translateSignaturePosition(final int sigXOffset, final int sigYOffset) {
-		EventQueue.invokeLater(() -> {
-			this.viewer.translateSignaturePagePosition(sigXOffset, sigYOffset);
-		});
+		this.viewer.translateSignaturePagePosition(sigXOffset, sigYOffset);
 	}
 
 	/**
diff --git a/pdf-over-gui/src/main/java/at/asit/pdfover/gui/composites/SignaturePanel.java b/pdf-over-gui/src/main/java/at/asit/pdfover/gui/composites/SignaturePanel.java
index fc47a386..6eb800b8 100644
--- a/pdf-over-gui/src/main/java/at/asit/pdfover/gui/composites/SignaturePanel.java
+++ b/pdf-over-gui/src/main/java/at/asit/pdfover/gui/composites/SignaturePanel.java
@@ -1,478 +1,528 @@
-/*
- * Copyright 2012 by A-SIT, Secure Information Technology Center Austria
- *
- * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
- * the European Commission - subsequent versions of the EUPL (the "Licence");
- * You may not use this work except in compliance with the Licence.
- * You may obtain a copy of the Licence at:
- * http://joinup.ec.europa.eu/software/page/eupl
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the Licence is distributed on an "AS IS" basis,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the Licence for the specific language governing permissions and
- * limitations under the Licence.
- */
-package at.asit.pdfover.gui.composites;
-
-// Imports
-import java.awt.BorderLayout;
-import java.awt.Color;
-import java.awt.Cursor;
-import java.awt.Dimension;
-import java.awt.Graphics;
-import java.awt.Image;
-import java.awt.event.MouseAdapter;
-import java.awt.event.MouseEvent;
-import java.awt.geom.Point2D;
-import java.awt.geom.Rectangle2D;
-import java.awt.image.BufferedImage;
-import java.io.IOException;
-
-import javax.swing.JPanel;
-
-import org.apache.pdfbox.pdmodel.PDDocument;
-import org.apache.pdfbox.pdmodel.PDPage;
-import org.apache.pdfbox.pdmodel.common.PDRectangle;
-import org.apache.pdfbox.rendering.PDFRenderer;
-
-import at.asit.pdfover.commons.Messages;
-import lombok.extern.slf4j.Slf4j;
-
-/**
- *
- */
-@Slf4j
-public class SignaturePanel extends JPanel {
-
-	/** Default serial version ID */
-	private static final long serialVersionUID = 1L;
-
-	/** The PDF file being displayed */
-	private PDDocument pdf = null;
-	private PDFRenderer renderer = null;
-
-	/** The image of the rendered PDF page being displayed */
-	Image currentImage = null;
-
-	/** The current scale for rendering pdf to image */
-	private float pageToImageScale;
-	/** The current scale for rendering image to screen */
-	private double imageToScreenScale;
-	/* scaling */
-	private enum U {
-		/* (0,0) is bottom-left of page */
-		PAGE_ABS,
-		/* (0,0) is top-left of page */
-		PAGE_REL,
-		/* pixels, (0,0) is top-left of image */
-		IMAGE,
-		/* pixels, (0,0) is top-left of image */
-		SCREEN_REL,
-		/* pixels, (0,0) is top-left of canvas */
-		SCREEN_ABS };
-	private enum Dim { X, Y };
-	private double scale(double v, U from, U to, Dim d)
-	{
-		if (from == to) return v;
-
-		if (from == U.PAGE_ABS) {
-			return scale((d == Dim.X) ? v : (this.pageHeight - v), U.PAGE_REL, to, d);
-		} else if (from == U.PAGE_REL) {
-			if (to == U.PAGE_ABS)
-				return ((d == Dim.X) ? v : (this.pageHeight - v));
-			else
-				return scale(v * this.pageToImageScale, U.IMAGE, to, d);
-		} else if (from == U.IMAGE) {
-			if ((to == U.PAGE_ABS) || (to == U.PAGE_REL))
-				return scale(v / this.pageToImageScale, U.PAGE_REL, to, d);
-			else
-				return scale(v * this.imageToScreenScale, U.SCREEN_REL, to, d);
-		} else if (from == U.SCREEN_REL) {
-			if (to == U.SCREEN_ABS)
-				return (v + ((d == Dim.X) ? this.offX : this.offY));
-			else
-				return scale(v / this.imageToScreenScale, U.IMAGE, to, d);
-		} else if (from == U.SCREEN_ABS) {
-			return scale(v - ((d == Dim.X) ? this.offX : this.offY), U.SCREEN_REL, to, d);
-		} else throw new RuntimeException("unreachable");
-	}
-
-	private float pageWidth = 0;
-	private float pageHeight = 0;
-	/** The horizontal offset of the image from the left edge of the panel */
-	private int offX = 0;
-	/** The vertical offset of the image from the top of the panel */
-	private int offY = 0;
-	/** The position of the top-left corner of the signature, in absolute page space */
-	private Point2D sigPagePos = null;
-	public Point2D getSigPagePos() { return this.sigPagePos; }
-	/** The signature placeholder image */
-	private Image sigPlaceholder = null;
-	/** Width of the signature placeholder in page space */
-	private int sigPageWidth = 0;
-	/** Height of the signature placeholder in page space */
-	private int sigPageHeight = 0;
-	/** Color of the signature placeholder border */
-	private Color sigPlaceholderBorderColor = Color.BLUE;
-	/** Current page */
-	private int currentPageNo = 0;
-	/** Number of pages in the document */
-	private int numPages = 0;
-	/** Cursor types */
-	private static enum Cursors {DEFAULT, HAND, MOVE};
-	/** Default arrow cursor */
-	private final Cursor defaultCursor = Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR);
-	/** Hand cursor */
-	private final Cursor handCursor = Cursor.getPredefinedCursor(Cursor.HAND_CURSOR);
-	/** Move cursor */
-	private final Cursor moveCursor = Cursor.getPredefinedCursor(Cursor.MOVE_CURSOR);
-	/** Current cursor */
-	private Cursors currentCursor = Cursors.DEFAULT;
-
-	/**
-	 * Create a new PagePanel.
-	 */
-	public SignaturePanel() {
-		super(new BorderLayout());
-		setDocument(null);
-		setFocusable(true);
-		addMouseListener(this.mouseListener);
-		addMouseMotionListener(this.mouseListener);
-	}
-
-	/**
-	 * Set a new document to be displayed
-	 * @param pdf the PDFFile to be displayed
-	 */
-	public void setDocument(PDDocument pdf) {
-		this.pdf = pdf;
-		this.sigPagePos = null;
-		if (pdf != null)
-		{
-			this.renderer = new PDFRenderer(pdf);
-			this.numPages = pdf.getNumberOfPages();
-			this.currentPageNo = -1;
-			showPage(this.numPages);
-		}
-		else
-		{
-			this.renderer = null;
-			this.currentPageNo = 0;
-			this.numPages = 0;
-			renderPageToImage();
-			repaint();
-		}
-	}
-
-	/**
-	 * Set the signature placeholder image
-	 * @param placeholder signature placeholder
-	 * @param width width of the placeholder in page space
-	 * @param height height of the placeholder in page space
-	 */
-	public void setSignaturePlaceholder(Image placeholder) {
-		this.sigPlaceholder = placeholder;
-		// TODO figure out why this is divided by 4 (factor ported from old code)
-		this.sigPageWidth = placeholder.getWidth(null) / 4;
-		this.sigPageHeight = placeholder.getHeight(null) / 4;
-		renderPageToImage();
-		if (this.sigPagePos != null)
-			setSignaturePosition(this.sigPagePos.getX(), this.sigPagePos.getY());
-		repaint();
-	}
-
-	/**
-	 * Set the color of the signature placeholder border
-	 * @param color new signature placeholder border color
-	 */
-	public void setSignaturePlaceholderBorderColor(Color color) {
-		this.sigPlaceholderBorderColor = color;
-	}
-
-	/**
-	 * Change the currently displayed page
-	 * @param page the number of the page to display
-	 */
-	public void showPage(int page) {
-		if (this.currentPageNo == page) return;
-		this.currentPageNo = page;
-		renderPageToImage();
-		repaint();
-	}
-
-	/**
-	 * Add and display a new page at the end of the document
-	 *
-	 * This page has the same dimensions as the old last page
-	 */
-	public void addNewLastPage() {
-		showPage(this.numPages + 1);
-	}
-
-	/**
-	 * Set the signature placeholder position
-	 * @param x the horizontal signature position
-	 * @param y the vertical signature position
-	 */
-	public void setSignaturePosition(double x, double y)
-	{
-		this.sigPagePos = new Point2D.Double(
-			clamp(x, 0, this.pageWidth - this.sigPageWidth),
-			clamp(y, this.sigPageHeight, this.pageHeight)
-		);
-		repaint();
-	}
-
-	public void translateSignaturePagePosition(float dX, float dY) {
-		setSignaturePosition(this.sigPagePos.getX() + dX, this.sigPagePos.getY() + dY);
-	}
-
-	/**
-	 * Stop the generation of any previous page, and draw the new one.
-	 *
-	 * @param page the PDFPage to draw.
-	 */
-	private synchronized void renderPageToImage() {
-		if (this.pdf == null)
-		{
-			this.currentImage = null;
-			return;
-		}
-
-		boolean newPage = false;
-		PDPage currentPage;
-		// set up the new page
-		if (this.currentPageNo > this.numPages)
-		{
-			// New last page - use old last page as template
-			currentPage = this.pdf.getPage(this.numPages-1);
-			newPage = true;
-		}
-		else
-			currentPage = this.pdf.getPage(this.currentPageNo-1);
-
-
-		if (currentPage == null) {
-			// no page
-			this.currentImage = null;
-			return;
-		}
-		
-		boolean isRotated = ((currentPage.getRotation()%180) == 90);
-		PDRectangle actualPageSize = currentPage.getBBox();
-		this.pageWidth = isRotated ? actualPageSize.getHeight() : actualPageSize.getWidth();
-		this.pageHeight = isRotated ? actualPageSize.getWidth() : actualPageSize.getHeight();
-		this.pageToImageScale = getToolkit().getScreenSize().height / this.pageHeight;
-
-		// get the new image
-		if (newPage)
-		{
-			int renderHeight = (int)(0.5 + this.scale(this.pageHeight, U.PAGE_REL, U.IMAGE, Dim.X));
-			int renderWidth = (int)(0.5 + this.scale(this.pageWidth, U.PAGE_REL, U.IMAGE, Dim.Y));
-			this.currentImage = new BufferedImage(renderWidth, renderHeight, BufferedImage.TYPE_INT_RGB);
-			Graphics g = this.currentImage.getGraphics();
-			g.setColor(Color.WHITE);
-			g.fillRect(0, 0, renderWidth, renderHeight);
-		}
-		else
-		{
-			int whichPage = Math.min(this.currentPageNo, this.numPages);
-
-			try {
-				this.currentImage = renderer.renderImage(whichPage-1, this.pageToImageScale);
-			} catch (IOException e) {
-				log.error(String.format("Failed to render image for page %d of %d", whichPage, this.numPages), e);
-				this.currentImage = null;
-			}
-		}
-
-		if (this.sigPagePos == null)
-		{
-			setSignaturePosition(
-				this.pageWidth * .5,
-				this.pageHeight * .25
-			);
-		}
-	}
-
-	/**
-	 * Draw the image.
-	 */
-	@Override
-	public void paint(Graphics g) {
-		Dimension renderPanelSize = getSize();
-		g.setColor(getBackground());
-		g.fillRect(0, 0, getWidth(), getHeight());
-		if (this.currentImage == null) {
-			g.setColor(Color.black);
-			g.drawString(Messages.getString("common.working"), getWidth() / 2 - 30, getHeight() / 2);
-		} else {
-			this.imageToScreenScale = Math.min(
-				renderPanelSize.getWidth() / this.currentImage.getWidth(null),
-				renderPanelSize.getHeight() / this.currentImage.getHeight(null));
-			// draw the image
-			int actualRenderWidth = (int)(this.currentImage.getWidth(null) * this.imageToScreenScale);
-			int actualRenderHeight = (int)(this.currentImage.getHeight(null) * this.imageToScreenScale);
-
-			// draw it centered within the panel
-			this.offX = (renderPanelSize.width - actualRenderWidth) / 2;
-			this.offY = (renderPanelSize.height - actualRenderHeight) / 2;
-
-			// draw document
-			g.drawImage(this.currentImage, this.offX, this.offY, actualRenderWidth, actualRenderHeight, null);
-			
-
-			// draw signature
-			int sigX = (int) this.scale(this.sigPagePos.getX(), U.PAGE_ABS, U.SCREEN_ABS, Dim.X);
-			int sigY = (int) this.scale(this.sigPagePos.getY(), U.PAGE_ABS, U.SCREEN_ABS, Dim.Y);
-			if (this.sigPlaceholder == null) {
-				g.setColor(Color.red);
-				g.drawRect(sigX, sigY, 100, 40);
-			}
-			else {
-				int sigScreenWidth = (int)this.scale(this.sigPageWidth, U.PAGE_REL, U.SCREEN_REL, Dim.X);
-				int sigScreenHeight = (int)this.scale(this.sigPageHeight, U.PAGE_REL, U.SCREEN_REL, Dim.Y);
-				g.drawImage(this.sigPlaceholder, sigX, sigY, sigScreenWidth, sigScreenHeight, null);
-				g.setColor(this.sigPlaceholderBorderColor);
-				g.drawRect(sigX, sigY, sigScreenWidth-1, sigScreenHeight-1);
-			}
-		}
-	}
-
-	/**
-	 * Handles notification of the fact that some part of the image changed.
-	 * Repaints that portion.
-	 *
-	 * @return true if more updates are desired.
-	 */
-	@Override
-	public boolean imageUpdate(Image img, int infoflags, int x, int y,
-			int width, int height) {
-		if ((infoflags & (SOMEBITS | ALLBITS)) != 0) {
-			repaint(x + this.offX, y + this.offY, width, height);
-		}
-		return ((infoflags & (ALLBITS | ERROR | ABORT)) == 0);
-	}
-
-	private MouseAdapter mouseListener = new MouseAdapter() {
-
-		private boolean doDrag = false;
-		private int dragXOffset = 0;
-		private int dragYOffset = 0;
-
-		private void updateSigPosDrag(MouseEvent evt) {
-			SignaturePanel.this.setSignaturePosition(
-				SignaturePanel.this.scale(evt.getX() - this.dragXOffset, U.SCREEN_ABS, U.PAGE_ABS, Dim.X),
-				SignaturePanel.this.scale(evt.getY() - this.dragYOffset, U.SCREEN_ABS, U.PAGE_ABS, Dim.Y)
-			);
-		}
-
-		/** Handles a mouseMoved event */
-		@Override
-		public void mouseMoved(MouseEvent evt) {
-			try {
-				boolean onSig = isOnSignature(evt);
-				setCursor(onSig ? Cursors.HAND : Cursors.DEFAULT);
-			} catch (NullPointerException e) {
-				// do nothing
-			}
-		}
-
-		/** Handles a mousePressed event */
-		@Override
-		public void mousePressed(MouseEvent evt) {
-			if (evt.getButton() == MouseEvent.BUTTON1)
-			{
-				this.doDrag = true;
-				if (isOnSignature(evt)) {
-					/* offsets (in screen units) from top-left corner of signature to cursor on drag start */
-					this.dragXOffset = (int)(evt.getX() - SignaturePanel.this.scale(SignaturePanel.this.sigPagePos.getX(), U.PAGE_ABS, U.SCREEN_ABS, Dim.X));
-					this.dragYOffset = (int)(evt.getY() - SignaturePanel.this.scale(SignaturePanel.this.sigPagePos.getY(), U.PAGE_ABS, U.SCREEN_ABS, Dim.Y));
-				} else {
-					this.dragXOffset = 0;
-					this.dragYOffset = 0;
-				}
-				updateSigPosDrag(evt);
-				setCursor(Cursors.MOVE);
-			}
-		}
-
-		/** Handles a mouseReleased event */
-		@Override
-		public void mouseReleased(MouseEvent evt) {
-			this.doDrag = false;
-			boolean onSig = isOnSignature(evt);
-			setCursor(onSig ? Cursors.HAND : Cursors.DEFAULT);
-		}
-
-		/**
-		 * Handles a mouseDragged event.
-		 */
-		@Override
-		public void mouseDragged(MouseEvent evt) {
-			if (this.doDrag)
-				updateSigPosDrag(evt);
-		}
-	};
-
-	/**
-	 * Sets the mouse cursor
-	 * @param cursor cursor to set
-	 */
-	void setCursor(Cursors cursor)
-	{
-		if (this.currentCursor == cursor)
-			return;
-		this.currentCursor = cursor;
-		Cursor cur = null;
-		switch (cursor) {
-			case DEFAULT:
-				cur = this.defaultCursor;
-				break;
-			case HAND:
-				cur = this.handCursor;
-				break;
-			case MOVE:
-				cur = this.moveCursor;
-				break;
-		}
-		this.getParent().setCursor(cur);
-	}
-
-	/**
-	 * Check whether given point is on signature placeholder
-	 * @param x x coordinate (screen)
-	 * @param y y coordinate (screen)
-	 * @return true if given point is on signature placeholder
-	 */
-	private boolean isOnSignature(MouseEvent evt)
-	{
-		if (this.sigPagePos == null)
-			return false;
-
-		Rectangle2D sig = new Rectangle2D.Double(
-			this.scale(this.sigPagePos.getX(), U.PAGE_ABS, U.SCREEN_ABS, Dim.X),
-			this.scale(this.sigPagePos.getY(), U.PAGE_ABS, U.SCREEN_ABS, Dim.Y),
-			this.scale(this.sigPageWidth, U.PAGE_REL, U.SCREEN_REL, Dim.X),
-			this.scale(this.sigPageHeight, U.PAGE_REL, U.SCREEN_REL, Dim.Y)
-		);
-		return sig.contains(evt.getX(), evt.getY());
-	}
-
-	/**
-	 * Clamp x to be within [min-max]
-	 * @param x int to clamp
-	 * @param min minimum value
-	 * @param max maximum value
-	 * @return clamped x
-	 */
-	private static double clamp(double x, double min, double max)
-	{
-		if (x < min)
-			x = min;
-		else if (x > max)
-			x = max;
-		return x;
-	}
-}
+/*
+ * Copyright 2012 by A-SIT, Secure Information Technology Center Austria
+ *
+ * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
+ * the European Commission - subsequent versions of the EUPL (the "Licence");
+ * You may not use this work except in compliance with the Licence.
+ * You may obtain a copy of the Licence at:
+ * http://joinup.ec.europa.eu/software/page/eupl
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the Licence is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the Licence for the specific language governing permissions and
+ * limitations under the Licence.
+ */
+package at.asit.pdfover.gui.composites;
+
+import java.awt.geom.Point2D;
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import org.apache.pdfbox.pdmodel.PDDocument;
+import org.apache.pdfbox.pdmodel.PDPage;
+import org.apache.pdfbox.pdmodel.common.PDRectangle;
+import org.apache.pdfbox.rendering.PDFRenderer;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.events.MouseAdapter;
+import org.eclipse.swt.events.MouseEvent;
+import org.eclipse.swt.events.MouseMoveListener;
+import org.eclipse.swt.graphics.Color;
+import org.eclipse.swt.graphics.GC;
+import org.eclipse.swt.graphics.Image;
+import org.eclipse.swt.graphics.ImageData;
+import org.eclipse.swt.graphics.Point;
+import org.eclipse.swt.graphics.Rectangle;
+import org.eclipse.swt.widgets.Canvas;
+import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Display;
+
+import at.asit.pdfover.commons.Messages;
+import at.asit.pdfover.commons.utils.ImageUtil;
+import lombok.extern.slf4j.Slf4j;
+
+/**
+ * Displays a PDF page and allows the user to place the signature placeholder.
+ */
+@Slf4j
+public class SignaturePanel extends Canvas {
+
+	/** The PDF file being displayed */
+	private PDDocument pdf = null;
+	private PDFRenderer renderer = null;
+
+	/** The image of the rendered PDF page being displayed */
+	private Image currentImage = null;
+
+	/** The current scale for rendering pdf to image */
+	private float pageToImageScale;
+	/** The current scale for rendering image to screen */
+	private double imageToScreenScale = 1.0;
+	/* scaling */
+	private enum U {
+		/* (0,0) is bottom-left of page */
+		PAGE_ABS,
+		/* (0,0) is top-left of page */
+		PAGE_REL,
+		/* pixels, (0,0) is top-left of image */
+		IMAGE,
+		/* pixels, (0,0) is top-left of image */
+		SCREEN_REL,
+		/* pixels, (0,0) is top-left of canvas */
+		SCREEN_ABS };
+	private enum Dim { X, Y };
+	private double scale(double v, U from, U to, Dim d)
+	{
+		if (from == to) return v;
+
+		if (from == U.PAGE_ABS) {
+			return scale((d == Dim.X) ? v : (this.pageHeight - v), U.PAGE_REL, to, d);
+		} else if (from == U.PAGE_REL) {
+			if (to == U.PAGE_ABS)
+				return ((d == Dim.X) ? v : (this.pageHeight - v));
+			else
+				return scale(v * this.pageToImageScale, U.IMAGE, to, d);
+		} else if (from == U.IMAGE) {
+			if ((to == U.PAGE_ABS) || (to == U.PAGE_REL))
+				return scale(v / this.pageToImageScale, U.PAGE_REL, to, d);
+			else
+				return scale(v * this.imageToScreenScale, U.SCREEN_REL, to, d);
+		} else if (from == U.SCREEN_REL) {
+			if (to == U.SCREEN_ABS)
+				return (v + ((d == Dim.X) ? this.offX : this.offY));
+			else
+				return scale(v / this.imageToScreenScale, U.IMAGE, to, d);
+		} else if (from == U.SCREEN_ABS) {
+			return scale(v - ((d == Dim.X) ? this.offX : this.offY), U.SCREEN_REL, to, d);
+		} else throw new RuntimeException("unreachable");
+	}
+
+	private float pageWidth = 0;
+	private float pageHeight = 0;
+	/** The horizontal offset of the image from the left edge of the panel */
+	private int offX = 0;
+	/** The vertical offset of the image from the top of the panel */
+	private int offY = 0;
+	/** The position of the top-left corner of the signature, in absolute page space */
+	private Point2D sigPagePos = null;
+	private Point2D pendingSigPagePos = null;
+	public Point2D getSigPagePos() { return this.sigPagePos; }
+	/** The signature placeholder image */
+	private Image sigPlaceholder = null;
+	/** Width of the signature placeholder in page space */
+	private int sigPageWidth = 0;
+	/** Height of the signature placeholder in page space */
+	private int sigPageHeight = 0;
+	/** Color of the signature placeholder border */
+	private Color sigPlaceholderBorderColor = null;
+	/** Current page */
+	private int currentPageNo = 0;
+	/** Number of pages in the document */
+	private int numPages = 0;
+	/** Cursor types */
+	private static enum Cursors {DEFAULT, HAND, MOVE};
+	/** Current cursor */
+	private Cursors currentCursor = Cursors.DEFAULT;
+	private final AtomicInteger renderGeneration = new AtomicInteger();
+	private final Object renderLock = new Object();
+	private boolean doDrag = false;
+	private int dragXOffset = 0;
+	private int dragYOffset = 0;
+	private Runnable signaturePositionAvailableCallback = null;
+
+	/**
+	 * Create a new PagePanel.
+	 */
+	public SignaturePanel(Composite parent, int style) {
+		super(parent, style | SWT.NO_BACKGROUND | SWT.DOUBLE_BUFFERED);
+		setDocument(null);
+		addPaintListener(e -> paint(e.gc));
+		addMouseListener(this.mouseListener);
+		addMouseMoveListener(this.mouseMoveListener);
+		addDisposeListener(e -> {
+			this.renderGeneration.incrementAndGet();
+			disposeCurrentImage();
+			disposePlaceholder();
+		});
+	}
+
+	/**
+	 * Set a new document to be displayed
+	 * @param pdf the PDFFile to be displayed
+	 */
+	public void setDocument(PDDocument pdf) {
+		if (isDisposed())
+			return;
+		this.renderGeneration.incrementAndGet();
+		synchronized (this.renderLock) {
+			this.pdf = pdf;
+			this.sigPagePos = null;
+			this.pendingSigPagePos = null;
+			if (pdf != null)
+			{
+				this.renderer = new PDFRenderer(pdf);
+				this.numPages = pdf.getNumberOfPages();
+				this.currentPageNo = -1;
+			}
+			else
+			{
+				this.renderer = null;
+				this.currentPageNo = 0;
+				this.numPages = 0;
+			}
+		}
+		if (pdf != null)
+			showPage(this.numPages);
+		else {
+			disposeCurrentImage();
+			if (!isDisposed())
+				redraw();
+		}
+	}
+
+	/**
+	 * Set the signature placeholder image
+	 * @param placeholder signature placeholder
+	 */
+	public void setSignaturePlaceholder(ImageData placeholder) {
+		if (isDisposed())
+			return;
+		disposePlaceholder();
+		if (placeholder != null) {
+			this.sigPlaceholder = new Image(getDisplay(), placeholder);
+			// TODO figure out why this is divided by 4 (factor ported from old code)
+			this.sigPageWidth = placeholder.width / 4;
+			this.sigPageHeight = placeholder.height / 4;
+		} else {
+			this.sigPageWidth = 0;
+			this.sigPageHeight = 0;
+		}
+		if (this.sigPagePos != null)
+			setSignaturePosition(this.sigPagePos.getX(), this.sigPagePos.getY());
+		redraw();
+	}
+
+	/**
+	 * Set the color of the signature placeholder border
+	 * @param color new signature placeholder border color
+	 */
+	public void setSignaturePlaceholderBorderColor(Color color) {
+		if (isDisposed())
+			return;
+		this.sigPlaceholderBorderColor = color;
+	}
+
+	public void setSignaturePositionAvailableCallback(Runnable callback) {
+		if (isDisposed())
+			return;
+		this.signaturePositionAvailableCallback = callback;
+	}
+
+	/**
+	 * Change the currently displayed page
+	 * @param page the number of the page to display
+	 */
+	public void showPage(int page) {
+		if (isDisposed())
+			return;
+		if (this.currentPageNo == page) return;
+		this.currentPageNo = page;
+		renderPageToImage();
+		redraw();
+	}
+
+	/**
+	 * Set the signature placeholder position
+	 * @param x the horizontal signature position
+	 * @param y the vertical signature position
+	 */
+	public void setSignaturePosition(double x, double y)
+	{
+		if (isDisposed())
+			return;
+		if (this.pageWidth <= 0 || this.pageHeight <= 0) {
+			this.pendingSigPagePos = new Point2D.Double(x, y);
+			return;
+		}
+		boolean hadNoSignaturePosition = (this.sigPagePos == null);
+		this.sigPagePos = new Point2D.Double(
+			clamp(x, 0, this.pageWidth - this.sigPageWidth),
+			clamp(y, this.sigPageHeight, this.pageHeight)
+		);
+		if (hadNoSignaturePosition && this.signaturePositionAvailableCallback != null)
+			this.signaturePositionAvailableCallback.run();
+		redraw();
+	}
+
+	public void translateSignaturePagePosition(float dX, float dY) {
+		if (isDisposed())
+			return;
+		if (this.sigPagePos != null)
+			setSignaturePosition(this.sigPagePos.getX() + dX, this.sigPagePos.getY() + dY);
+	}
+
+	private void disposeCurrentImage() {
+		if (this.currentImage != null && !this.currentImage.isDisposed())
+			this.currentImage.dispose();
+		this.currentImage = null;
+	}
+
+	private void disposePlaceholder() {
+		if (this.sigPlaceholder != null && !this.sigPlaceholder.isDisposed())
+			this.sigPlaceholder.dispose();
+		this.sigPlaceholder = null;
+	}
+
+	/**
+	 * Stop the generation of any previous page, and draw the new one.
+	 */
+	private void renderPageToImage() {
+		if (isDisposed())
+			return;
+		final int generation = this.renderGeneration.incrementAndGet();
+		final int pageNo = this.currentPageNo;
+		final int screenHeight = getShell().getMonitor().getBounds().height;
+		final Display display = getDisplay();
+
+		Thread renderThread = new Thread(() -> {
+			ImageData imageData = null;
+			float renderedPageWidth = 0;
+			float renderedPageHeight = 0;
+			float renderedScale = 1;
+
+			try {
+				synchronized (this.renderLock) {
+					if (this.pdf == null || generation != this.renderGeneration.get())
+						return;
+
+					boolean newPage = false;
+					PDPage currentPage;
+					if (pageNo > this.numPages)
+					{
+						currentPage = this.pdf.getPage(this.numPages-1);
+						newPage = true;
+					}
+					else
+						currentPage = this.pdf.getPage(pageNo-1);
+
+					if (currentPage == null)
+						return;
+
+					boolean isRotated = ((currentPage.getRotation()%180) == 90);
+					PDRectangle actualPageSize = currentPage.getBBox();
+					renderedPageWidth = isRotated ? actualPageSize.getHeight() : actualPageSize.getWidth();
+					renderedPageHeight = isRotated ? actualPageSize.getWidth() : actualPageSize.getHeight();
+					renderedScale = screenHeight / renderedPageHeight;
+
+					if (newPage)
+					{
+						int renderHeight = (int)(0.5 + (renderedPageHeight * renderedScale));
+						int renderWidth = (int)(0.5 + (renderedPageWidth * renderedScale));
+						BufferedImage blankImage = new BufferedImage(renderWidth, renderHeight, BufferedImage.TYPE_INT_RGB);
+						java.awt.Graphics g = blankImage.getGraphics();
+						g.setColor(java.awt.Color.WHITE);
+						g.fillRect(0, 0, renderWidth, renderHeight);
+						g.dispose();
+						imageData = ImageUtil.convertToSWT(blankImage);
+					}
+					else
+					{
+						int whichPage = Math.min(pageNo, this.numPages);
+						BufferedImage renderedImage = this.renderer.renderImage(whichPage-1, renderedScale);
+						imageData = ImageUtil.convertToSWT(convertToRGB(renderedImage));
+					}
+				}
+			} catch (IOException e) {
+				log.error(String.format("Failed to render image for page %d of %d", Math.min(pageNo, this.numPages), this.numPages), e);
+			} catch (RuntimeException e) {
+				log.error(String.format("Failed to prepare image for page %d of %d", Math.min(pageNo, this.numPages), this.numPages), e);
+			}
+
+			final ImageData finalImageData = imageData;
+			final float finalPageWidth = renderedPageWidth;
+			final float finalPageHeight = renderedPageHeight;
+			final float finalScale = renderedScale;
+			if (display.isDisposed())
+				return;
+			display.asyncExec(() -> {
+				if (isDisposed() || generation != this.renderGeneration.get())
+					return;
+				disposeCurrentImage();
+				this.pageWidth = finalPageWidth;
+				this.pageHeight = finalPageHeight;
+				this.pageToImageScale = finalScale;
+				if (finalImageData != null)
+					this.currentImage = new Image(display, finalImageData);
+				if (this.pendingSigPagePos != null) {
+					Point2D pendingPosition = this.pendingSigPagePos;
+					this.pendingSigPagePos = null;
+					setSignaturePosition(pendingPosition.getX(), pendingPosition.getY());
+				} else if (this.sigPagePos != null) {
+					setSignaturePosition(this.sigPagePos.getX(), this.sigPagePos.getY());
+				} else if (this.sigPagePos == null && this.pageWidth > 0 && this.pageHeight > 0) {
+					setSignaturePosition(this.pageWidth * .5, this.pageHeight * .25);
+				}
+				redraw();
+			});
+		}, "PDF-Over page renderer");
+		renderThread.setDaemon(true);
+		renderThread.start();
+	}
+
+	private static BufferedImage convertToRGB(BufferedImage image) {
+		if (image.getType() == BufferedImage.TYPE_INT_RGB)
+			return image;
+		BufferedImage rgbImage = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_RGB);
+		java.awt.Graphics g = rgbImage.getGraphics();
+		g.drawImage(image, 0, 0, java.awt.Color.WHITE, null);
+		g.dispose();
+		return rgbImage;
+	}
+
+	/**
+	 * Draw the image.
+	 */
+	private void paint(GC gc) {
+		Point renderPanelSize = getSize();
+		gc.setBackground(getBackground());
+		gc.fillRectangle(0, 0, renderPanelSize.x, renderPanelSize.y);
+		if (this.currentImage == null) {
+			gc.setForeground(getDisplay().getSystemColor(SWT.COLOR_BLACK));
+			gc.drawString(Messages.getString("common.working"), Math.max(0, renderPanelSize.x / 2 - 30), Math.max(0, renderPanelSize.y / 2), true);
+		} else {
+			Rectangle imageBounds = this.currentImage.getBounds();
+			this.imageToScreenScale = Math.min(
+				renderPanelSize.x / (double)imageBounds.width,
+				renderPanelSize.y / (double)imageBounds.height);
+			int actualRenderWidth = (int)(imageBounds.width * this.imageToScreenScale);
+			int actualRenderHeight = (int)(imageBounds.height * this.imageToScreenScale);
+
+			this.offX = (renderPanelSize.x - actualRenderWidth) / 2;
+			this.offY = (renderPanelSize.y - actualRenderHeight) / 2;
+
+			gc.drawImage(this.currentImage, 0, 0, imageBounds.width, imageBounds.height, this.offX, this.offY, actualRenderWidth, actualRenderHeight);
+
+			if (this.sigPagePos == null)
+				return;
+
+			int sigX = (int) this.scale(this.sigPagePos.getX(), U.PAGE_ABS, U.SCREEN_ABS, Dim.X);
+			int sigY = (int) this.scale(this.sigPagePos.getY(), U.PAGE_ABS, U.SCREEN_ABS, Dim.Y);
+			if (this.sigPlaceholder == null) {
+				gc.setForeground(getDisplay().getSystemColor(SWT.COLOR_RED));
+				gc.drawRectangle(sigX, sigY, 100, 40);
+			}
+			else {
+				Rectangle placeholderBounds = this.sigPlaceholder.getBounds();
+				int sigScreenWidth = (int)this.scale(this.sigPageWidth, U.PAGE_REL, U.SCREEN_REL, Dim.X);
+				int sigScreenHeight = (int)this.scale(this.sigPageHeight, U.PAGE_REL, U.SCREEN_REL, Dim.Y);
+				gc.drawImage(this.sigPlaceholder, 0, 0, placeholderBounds.width, placeholderBounds.height, sigX, sigY, sigScreenWidth, sigScreenHeight);
+				gc.setForeground(this.sigPlaceholderBorderColor != null ? this.sigPlaceholderBorderColor : getDisplay().getSystemColor(SWT.COLOR_BLUE));
+				gc.drawRectangle(sigX, sigY, sigScreenWidth-1, sigScreenHeight-1);
+			}
+		}
+	}
+
+	private MouseMoveListener mouseMoveListener = evt -> {
+		if (this.doDrag) {
+			updateSigPosDrag(evt);
+			return;
+		}
+		try {
+			boolean onSig = isOnSignature(evt);
+			setCursor(onSig ? Cursors.HAND : Cursors.DEFAULT);
+		} catch (NullPointerException e) {
+			// do nothing
+		}
+	};
+
+	private MouseAdapter mouseListener = new MouseAdapter() {
+		/** Handles a mousePressed event */
+		@Override
+		public void mouseDown(MouseEvent evt) {
+			if (evt.button == 1)
+			{
+				setFocus();
+				SignaturePanel.this.doDrag = true;
+				if (isOnSignature(evt)) {
+					SignaturePanel.this.dragXOffset = (int)(evt.x - SignaturePanel.this.scale(SignaturePanel.this.sigPagePos.getX(), U.PAGE_ABS, U.SCREEN_ABS, Dim.X));
+					SignaturePanel.this.dragYOffset = (int)(evt.y - SignaturePanel.this.scale(SignaturePanel.this.sigPagePos.getY(), U.PAGE_ABS, U.SCREEN_ABS, Dim.Y));
+				} else {
+					SignaturePanel.this.dragXOffset = 0;
+					SignaturePanel.this.dragYOffset = 0;
+				}
+				updateSigPosDrag(evt);
+				setCursor(Cursors.MOVE);
+			}
+		}
+
+		/** Handles a mouseReleased event */
+		@Override
+		public void mouseUp(MouseEvent evt) {
+			SignaturePanel.this.doDrag = false;
+			boolean onSig = isOnSignature(evt);
+			setCursor(onSig ? Cursors.HAND : Cursors.DEFAULT);
+		}
+	};
+
+	private void updateSigPosDrag(MouseEvent evt) {
+		setSignaturePosition(
+			scale(evt.x - this.dragXOffset, U.SCREEN_ABS, U.PAGE_ABS, Dim.X),
+			scale(evt.y - this.dragYOffset, U.SCREEN_ABS, U.PAGE_ABS, Dim.Y)
+		);
+	}
+
+	/**
+	 * Sets the mouse cursor
+	 * @param cursor cursor to set
+	 */
+	void setCursor(Cursors cursor)
+	{
+		if (this.currentCursor == cursor)
+			return;
+		this.currentCursor = cursor;
+		switch (cursor) {
+			case DEFAULT:
+				setCursor(getDisplay().getSystemCursor(SWT.CURSOR_ARROW));
+				break;
+			case HAND:
+				setCursor(getDisplay().getSystemCursor(SWT.CURSOR_HAND));
+				break;
+			case MOVE:
+				setCursor(getDisplay().getSystemCursor(SWT.CURSOR_SIZEALL));
+				break;
+		}
+	}
+
+	/**
+	 * Check whether given point is on signature placeholder
+	 * @return true if given point is on signature placeholder
+	 */
+	private boolean isOnSignature(MouseEvent evt)
+	{
+		if (this.sigPagePos == null)
+			return false;
+
+		double sigX = this.scale(this.sigPagePos.getX(), U.PAGE_ABS, U.SCREEN_ABS, Dim.X);
+		double sigY = this.scale(this.sigPagePos.getY(), U.PAGE_ABS, U.SCREEN_ABS, Dim.Y);
+		double sigWidth = this.scale(this.sigPageWidth, U.PAGE_REL, U.SCREEN_REL, Dim.X);
+		double sigHeight = this.scale(this.sigPageHeight, U.PAGE_REL, U.SCREEN_REL, Dim.Y);
+		return (evt.x >= sigX) && (evt.x <= (sigX + sigWidth)) && (evt.y >= sigY) && (evt.y <= (sigY + sigHeight));
+	}
+
+	/**
+	 * Clamp x to be within [min-max]
+	 * @param x int to clamp
+	 * @param min minimum value
+	 * @param max maximum value
+	 * @return clamped x
+	 */
+	private static double clamp(double x, double min, double max)
+	{
+		if (x < min)
+			x = min;
+		else if (x > max)
+			x = max;
+		return x;
+	}
+}
diff --git a/pdf-over-gui/src/main/java/at/asit/pdfover/gui/workflow/states/PositioningState.java b/pdf-over-gui/src/main/java/at/asit/pdfover/gui/workflow/states/PositioningState.java
index cf7e91c8..753c7b32 100644
--- a/pdf-over-gui/src/main/java/at/asit/pdfover/gui/workflow/states/PositioningState.java
+++ b/pdf-over-gui/src/main/java/at/asit/pdfover/gui/workflow/states/PositioningState.java
@@ -63,6 +63,8 @@ private void closePDFDocument() {
 
 		if (this.document != null)
 		{
+			if (this.positionComposite != null && !this.positionComposite.isDisposed())
+				this.positionComposite.clearDocument();
 			try { this.document.close(); } catch (IOException e) { log.warn("Failed to close PDF", e); }
 			this.document = null;
 		}
@@ -117,7 +119,7 @@ private PositioningComposite getPositioningComposite(PDDocument document) {
 
 		PdfAs4SignaturePlaceholder.For(param, (p) -> {
 			if (p.hasImage())
-				this.positionComposite.setPlaceholder(p.getAWTImage());
+				this.positionComposite.setPlaceholder(p.getSWTImage());
 		});
 
 		if (this.previousPosition != null && !this.previousPosition.useAutoPositioning())