eclient/org.eclipse.statet.rj.eclient.graphics/src/org/eclipse/statet/rj/eclient/graphics/RGraphicComposite.java - statet/org.eclipse.statet-rj - Git at Google

 /*=============================================================================#
  # Copyright (c) 2009, 2021 Stephan Wahlbrink and others.
  #
  # This program and the accompanying materials are made available under the
  # terms of the Eclipse Public License 2.0 which is available at
  # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
  # which is available at https://www.apache.org/licenses/LICENSE-2.0.
  #
  # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
  #
  # Contributors:
  #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
  #=============================================================================*/

 package org.eclipse.statet.rj.eclient.graphics;

 import java.util.List;

 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.DisposeEvent;
 import org.eclipse.swt.events.DisposeListener;
 import org.eclipse.swt.events.MouseEvent;
 import org.eclipse.swt.events.MouseListener;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Event;
 import org.eclipse.swt.widgets.Layout;
 import org.eclipse.swt.widgets.Listener;
 import org.eclipse.swt.widgets.ScrollBar;


 /**
  * Composite to display an R graphic.
  */
 public class RGraphicComposite extends Composite
 		implements ERGraphic.ListenerInstructionsExtension, ERGraphic.ListenerLocatorExtension {


 	/**
 	 * This class provides the layout for RGraphicComposite
 	 */
 	private static class ScrolledCompositeLayout extends Layout {

 		static final int DEFAULT_WIDTH	= 64;
 		static final int DEFAULT_HEIGHT	= 64;


 		private boolean inLayout= false;


 		public ScrolledCompositeLayout() {
 		}


 		@Override
 		protected boolean flushCache(final Control control) {
 			return true;
 		}

 		@Override
 		protected Point computeSize(final Composite composite, final int wHint, final int hHint, final boolean flushCache) {
 			final RGraphicComposite sc= (RGraphicComposite) composite;
 			final Point size= new Point(wHint, hHint);
 			if (wHint == SWT.DEFAULT) {
 				size.x= Math.max(DEFAULT_WIDTH, sc.width);
 			}
 			if (hHint == SWT.DEFAULT) {
 				size.y= Math.max(DEFAULT_HEIGHT, sc.height);
 			}
 			return size;
 		}

 		@Override
 		protected void layout(final Composite composite, final boolean flushCache) {
 			if (this.inLayout || composite == null) {
 				return;
 			}
 			final RGraphicComposite sc= (RGraphicComposite) composite;
 			final ScrollBar hBar= sc.getHorizontalBar();
 			final ScrollBar vBar= sc.getVerticalBar();

 			if (hBar.getSize().y >= sc.getSize().y) {
 				return;
 			}
 			if (vBar.getSize().x >= sc.getSize().x) {
 				return;
 			}

 			this.inLayout= true;

 			final Rectangle previousBounds= sc.canvas.getBounds();
 			boolean hVisible= sc.needHBar(previousBounds, false);
 			final boolean vVisible= sc.needVBar(previousBounds, hVisible);
 			if (!hVisible && vVisible) {
 				hVisible= sc.needHBar(previousBounds, vVisible);
 			}
 			hBar.setVisible(hVisible);
 			vBar.setVisible(vVisible);

 			final Rectangle clientArea= sc.getClientArea();
 			final int x;
 			final int y;
 			final int width= sc.width;
 			final int height= sc.height;
 			hBar.setThumb(clientArea.width);
 			hBar.setPageIncrement(clientArea.width);
 			if (hVisible) {
 				x= (sc.changedLayout || previousBounds.x >= 0) ? 0 :
 						Math.max(previousBounds.x, clientArea.width - width);
 				hBar.setSelection(-x);
 			}
 			else {
 				x= (clientArea.width - width) / 2;
 				hBar.setSelection(0);
 			}
 			vBar.setThumb(clientArea.height);
 			vBar.setPageIncrement(clientArea.height);
 			if (vVisible) {
 				y= (sc.changedLayout || previousBounds.y >= 0) ? 0 :
 						Math.max(previousBounds.y, clientArea.height - height);
 				vBar.setSelection(-y);
 			}
 			else {
 				y= (clientArea.height - height) / 2;
 				vBar.setSelection(0);
 			}

 			sc.changedLayout= false;
 			sc.canvas.setBounds(x, y, width, height);
 			this.inLayout= false;
 		}

 	}

 	private class PanListener implements Listener {

 		private boolean started;
 		private Point startMouse;

 		@Override
 		public void handleEvent(final Event event) {
 			switch (event.type) {
 			case SWT.MouseDown:
 				if (event.button == 2) {
 					this.started= true;
 					updateCursor();

 					this.startMouse= checkedPoint(event);
 					return;
 				}
 				else {
 					this.started= false;
 					return;
 				}
 			case SWT.MouseExit:
 			case SWT.MouseMove:
 				if (this.started) {
 					pan(checkedPoint(event));
 					return;
 				}
 				else {
 					return;
 				}
 			case SWT.MouseUp:
 				if (this.started && event.button == 2) {
 					this.started= false;
 					updateCursor();
 					return;
 				}
 				else {
 					return;
 				}
 			case SWT.KeyDown:
 				switch (event.keyCode) {
 				case SWT.ARROW_DOWN:
 					if (update(getVerticalBar(), RGraphicComposite.this.panIncrement)) {
 						scrollV();
 					}
 					return;
 				case SWT.ARROW_UP:
 					if (update(getVerticalBar(), -RGraphicComposite.this.panIncrement)) {
 						scrollV();
 					}
 					return;
 				case SWT.ARROW_RIGHT:
 					if (update(getHorizontalBar(), RGraphicComposite.this.panIncrement)) {
 						scrollH();
 					}
 					return;
 				case SWT.ARROW_LEFT:
 					if (update(getHorizontalBar(), -RGraphicComposite.this.panIncrement)) {
 						scrollH();
 					}
 					return;
 				default:
 					return;
 				}
 			}
 		}

 		private Point checkedPoint(final Event event) {
 			if (event.item == RGraphicComposite.this) {
 				return new Point(event.x, event.y);
 			}
 			else {
 				final Point point= ((Control) event.widget).toDisplay(event.x, event.y);
 				return RGraphicComposite.this.toControl(point);
 			}
 		}

 		private void pan(final Point point) {
 			if (update(getHorizontalBar(), this.startMouse.x - point.x)) {
 				scrollH();
 			}
 			if (update(getVerticalBar(), this.startMouse.y - point.y)) {
 				scrollV();
 			}
 			this.startMouse= point;
 		}

 		private boolean update(final ScrollBar bar, final int step) {
 			if (bar != null && bar.isVisible()) {
 				int selection= bar.getSelection() + step;
 				if (selection < 0) {
 					selection= 0;
 				}
 				else if (selection > bar.getMaximum()) {
 					selection= bar.getMaximum() - bar.getThumb();
 				}
 				bar.setSelection(selection);
 				return true;
 			}
 			return false;
 		}

 	}


 	private static int checkStyle (final int style) {
 		final int mask= SWT.H_SCROLL | SWT.V_SCROLL | SWT.BORDER | SWT.LEFT_TO_RIGHT | SWT.RIGHT_TO_LEFT;
 		return style & mask;
 	}


 	private ERGraphic graphic;

 	private RGraphicCanvas canvas;

 	private int width= 0;
 	private int height= 0;

 	private boolean changedLayout;
 	private boolean changedContent;

 	private int panIncrement;
 	private final PanListener panListener;

 	private MouseListener locatorListener;


 	public RGraphicComposite(final Composite parent, final ERGraphic graphic) {
 		super(parent, checkStyle(SWT.H_SCROLL | SWT.V_SCROLL));
 		super.setLayout(new ScrolledCompositeLayout());

 		this.panIncrement= 10;

 		final ScrollBar hBar= getHorizontalBar();
 		hBar.setVisible(false);
 		hBar.addListener(SWT.Selection, new Listener() {
 			@Override
 			public void handleEvent(final Event event) {
 				scrollH();
 			}
 		});
 		hBar.setIncrement(this.panIncrement);
 		final ScrollBar vBar= getVerticalBar();
 		vBar.setVisible(false);
 		vBar.addListener(SWT.Selection, new Listener() {
 			@Override
 			public void handleEvent(final Event event) {
 				scrollV();
 			}
 		});
 		vBar.setIncrement(this.panIncrement);
 		addListener(SWT.Resize, new Listener() {
 			@Override
 			public void handleEvent(final Event event) {
 //				checkContentSize();
 			}
 		});
 		createCanvas();
 		final Listener updateListener= new Listener() {
 			@Override
 			public void handleEvent(final Event event) {
 				if (RGraphicComposite.this.changedContent) {
 					updateGraphic();
 				}
 			}
 		};
 		addListener(SWT.Show, updateListener);
 		addListener(SWT.Activate, updateListener);

 		this.panListener= new PanListener();
 		addListener(SWT.MouseDown, this.panListener);
 		addListener(SWT.MouseMove, this.panListener);
 		addListener(SWT.MouseExit, this.panListener);
 		addListener(SWT.MouseUp, this.panListener);
 		addListener(SWT.KeyDown, this.panListener);
 		this.canvas.addListener(SWT.MouseDown, this.panListener);
 		this.canvas.addListener(SWT.MouseMove, this.panListener);
 		this.canvas.addListener(SWT.MouseExit, this.panListener);
 		this.canvas.addListener(SWT.MouseUp, this.panListener);
 		this.canvas.addListener(SWT.KeyDown, this.panListener);

 		setGraphic(graphic);

 		addDisposeListener(new DisposeListener() {
 			@Override
 			public void widgetDisposed(final DisposeEvent e) {
 				disconnect();
 			}
 		});
 	}

 	private void createCanvas() {
 		this.canvas= new RGraphicCanvas(this);
 	}

 	boolean needHBar(final Rectangle contentRect, final boolean vVisible) {
 		final Rectangle hostRect= getBounds();
 		hostRect.width-= 2 * getBorderWidth();
 		if (vVisible) {
 			hostRect.width-= getVerticalBar().getSize().x;
 		}
 		return (this.width > hostRect.width);
 	}

 	boolean needVBar(final Rectangle contentRect, final boolean hVisible) {
 		final Rectangle hostRect= getBounds();
 		hostRect.height-= 2 * getBorderWidth();
 		if (hVisible) {
 			hostRect.height-= getHorizontalBar().getSize().y;
 		}
 		return (this.height > hostRect.height);
 	}

 	private void scrollH() {
 		final Point location= this.canvas.getLocation();
 		final ScrollBar hBar= getHorizontalBar();
 		if (hBar != null && hBar.isVisible()) {
 			final int hSelection= hBar.getSelection();
 			this.canvas.setLocation(-hSelection, location.y);
 		}
 	}

 	private void scrollV() {
 		final Point location= this.canvas.getLocation();
 		final ScrollBar vBar= getVerticalBar();
 		if (vBar != null && vBar.isVisible()) {
 			final int vSelection= vBar.getSelection();
 			this.canvas.setLocation(location.x, -vSelection);
 		}
 	}


 	protected void disconnect() {
 		if (this.graphic != null) {
 			this.graphic.removeListener(this);
 		}
 		locatorStopped();
 	}

 	public void setGraphic(final ERGraphic graphic) {
 		disconnect();

 		this.graphic= graphic;
 		if (this.graphic != null) {
 			this.graphic.addListener(this);
 		}

 		instructionsChanged(true, null);

 		if (this.graphic != null && this.graphic.isLocatorStarted()) {
 			locatorStarted();
 		}
 	}

 	/**
 	 * {@inheritDoc}
 	 * <p>
 	 * Note: No Layout can be set on this Control because it already
 	 * manages the size and position of its children.</p>
 	 */
 	@Override
 	public void setLayout (final Layout layout) {
 		checkWidget();
 		return;
 	}

 	@Override
 	public void activated() {
 	}

 	@Override
 	public void deactivated() {
 	}

 	@Override
 	public void drawingStarted() {
 	}

 	@Override
 	public void instructionsChanged(final boolean reset, final List<ERGraphicInstruction> added) {
 		this.changedContent= true;
 		if (isVisible()) {
 			updateGraphic();
 		}
 	}

 	@Override
 	public void drawingStopped() {
 	}

 	@Override
 	public void locatorStarted() {
 		if (this.locatorListener == null) {
 			this.locatorListener= new MouseListener() {
 				@Override
 				public void mouseDown(final MouseEvent e) {
 					switch (e.button) {
 					case 1:
 						RGraphicComposite.this.graphic.returnLocator(
 								RGraphicComposite.this.canvas.widget2graphicsX(e.x), RGraphicComposite.this.canvas.widget2graphicY(e.y));
 						break;
 					case 3:
 						RGraphicComposite.this.graphic.stopLocator(ERGraphic.LOCATOR_DONE);
 						break;
 					default:
 						break;
 					}
 				}
 				@Override
 				public void mouseUp(final MouseEvent e) {
 				}
 				@Override
 				public void mouseDoubleClick(final MouseEvent e) {
 				}
 			};
 			this.canvas.addMouseListener(this.locatorListener);
 			updateCursor();
 		}
 	}

 	@Override
 	public void locatorStopped() {
 		if (this.locatorListener != null) {
 			this.canvas.removeMouseListener(this.locatorListener);
 			this.locatorListener= null;
 			updateCursor();
 		}
 	}

 	private void updateCursor() {
 		if (this.panListener.started) {
 			this.canvas.setCursor(Display.getCurrent().getSystemCursor(SWT.CURSOR_HAND));
 		}
 		else if (this.locatorListener != null) {
 			this.canvas.setCursor(Display.getCurrent().getSystemCursor(SWT.CURSOR_CROSS));
 		}
 		else {
 			this.canvas.setCursor(null);
 		}
 	}

 	private void checkContentSize() {
 		final Point size= this.canvas.computeSize(SWT.DEFAULT, SWT.DEFAULT);
 		if (this.width == size.x && this.height == size.y) {
 			return;
 		}
 		this.changedLayout= true;
 		this.width= size.x;
 		this.height= size.y;
 		this.canvas.setSize(this.width, this.height);

 		final ScrollBar hBar= getHorizontalBar();
 		hBar.setMaximum(this.width);

 		final ScrollBar vBar= getVerticalBar();
 		vBar.setMaximum(this.height);
 		layout(false);
 	}


 	public void redrawGraphic() {
 		this.canvas.redraw();
 	}

 	private void updateGraphic() {
 		this.changedContent= false;
 		final List<? extends ERGraphicInstruction> instructions= (this.graphic != null) ?
 				this.graphic.getInstructions() : RGraphicCanvas.NO_GRAPHIC;
 		this.canvas.setInstructions(instructions);
 		checkContentSize();
 		this.canvas.redraw();
 	}

 	public double[] getGraphicFitSize() {
 		final Rectangle bounds= getBounds();
 		return new double[] { bounds.width, bounds.height };
 	}

 	public Control getControl() {
 		return this;
 	}

 	/**
 	 * Returns the control on which the graphic is painted
 	 *
 	 * @since 1.0
 	 */
 	public Control getGraphicWidget() {
 		return this.canvas;
 	}

 	/**
 	 * Converts a horizontal display coordinate of the {@link #getGraphicWidget() graphic widget}
 	 * to its graphic coordinate value.
 	 *
 	 * @since 1.0
 	 * @see ERGraphic Coordinate systems of R graphics
 	 */
 	public double convertWidget2GraphicX(final int x) {
 		return this.canvas.widget2graphicsX(x);
 	}

 	/**
 	 * Converts a vertical display coordinate of the {@link #getGraphicWidget() graphic widget}
 	 * to its graphic coordinate value.
 	 *
 	 * @since 1.0
 	 * @see ERGraphic Coordinate systems of R graphics
 	 */
 	public double convertWidget2GraphicY(final int y) {
 		return this.canvas.widget2graphicY(y);
 	}

 }
	/*=============================================================================#
	# Copyright (c) 2009, 2021 Stephan Wahlbrink and others.
	#
	# This program and the accompanying materials are made available under the
	# terms of the Eclipse Public License 2.0 which is available at
	# https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
	# which is available at https://www.apache.org/licenses/LICENSE-2.0.
	#
	# SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
	#
	# Contributors:
	# Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
	#=============================================================================*/

	package org.eclipse.statet.rj.eclient.graphics;

	import java.util.List;

	import org.eclipse.swt.SWT;
	import org.eclipse.swt.events.DisposeEvent;
	import org.eclipse.swt.events.DisposeListener;
	import org.eclipse.swt.events.MouseEvent;
	import org.eclipse.swt.events.MouseListener;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.graphics.Rectangle;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Display;
	import org.eclipse.swt.widgets.Event;
	import org.eclipse.swt.widgets.Layout;
	import org.eclipse.swt.widgets.Listener;
	import org.eclipse.swt.widgets.ScrollBar;


	/**
	* Composite to display an R graphic.
	*/
	public class RGraphicComposite extends Composite
	implements ERGraphic.ListenerInstructionsExtension, ERGraphic.ListenerLocatorExtension {


	/**
	* This class provides the layout for RGraphicComposite
	*/
	private static class ScrolledCompositeLayout extends Layout {

	static final int DEFAULT_WIDTH = 64;
	static final int DEFAULT_HEIGHT = 64;


	private boolean inLayout= false;


	public ScrolledCompositeLayout() {
	}


	@Override
	protected boolean flushCache(final Control control) {
	return true;
	}

	@Override
	protected Point computeSize(final Composite composite, final int wHint, final int hHint, final boolean flushCache) {
	final RGraphicComposite sc= (RGraphicComposite) composite;
	final Point size= new Point(wHint, hHint);
	if (wHint == SWT.DEFAULT) {
	size.x= Math.max(DEFAULT_WIDTH, sc.width);
	}
	if (hHint == SWT.DEFAULT) {
	size.y= Math.max(DEFAULT_HEIGHT, sc.height);
	}
	return size;
	}

	@Override
	protected void layout(final Composite composite, final boolean flushCache) {
	if (this.inLayout \|\| composite == null) {
	return;
	}
	final RGraphicComposite sc= (RGraphicComposite) composite;
	final ScrollBar hBar= sc.getHorizontalBar();
	final ScrollBar vBar= sc.getVerticalBar();

	if (hBar.getSize().y >= sc.getSize().y) {
	return;
	}
	if (vBar.getSize().x >= sc.getSize().x) {
	return;
	}

	this.inLayout= true;

	final Rectangle previousBounds= sc.canvas.getBounds();
	boolean hVisible= sc.needHBar(previousBounds, false);
	final boolean vVisible= sc.needVBar(previousBounds, hVisible);
	if (!hVisible && vVisible) {
	hVisible= sc.needHBar(previousBounds, vVisible);
	}
	hBar.setVisible(hVisible);
	vBar.setVisible(vVisible);

	final Rectangle clientArea= sc.getClientArea();
	final int x;
	final int y;
	final int width= sc.width;
	final int height= sc.height;
	hBar.setThumb(clientArea.width);
	hBar.setPageIncrement(clientArea.width);
	if (hVisible) {
	x= (sc.changedLayout \|\| previousBounds.x >= 0) ? 0 :
	Math.max(previousBounds.x, clientArea.width - width);
	hBar.setSelection(-x);
	}
	else {
	x= (clientArea.width - width) / 2;
	hBar.setSelection(0);
	}
	vBar.setThumb(clientArea.height);
	vBar.setPageIncrement(clientArea.height);
	if (vVisible) {
	y= (sc.changedLayout \|\| previousBounds.y >= 0) ? 0 :
	Math.max(previousBounds.y, clientArea.height - height);
	vBar.setSelection(-y);
	}
	else {
	y= (clientArea.height - height) / 2;
	vBar.setSelection(0);
	}

	sc.changedLayout= false;
	sc.canvas.setBounds(x, y, width, height);
	this.inLayout= false;
	}

	}

	private class PanListener implements Listener {

	private boolean started;
	private Point startMouse;

	@Override
	public void handleEvent(final Event event) {
	switch (event.type) {
	case SWT.MouseDown:
	if (event.button == 2) {
	this.started= true;
	updateCursor();

	this.startMouse= checkedPoint(event);
	return;
	}
	else {
	this.started= false;
	return;
	}
	case SWT.MouseExit:
	case SWT.MouseMove:
	if (this.started) {
	pan(checkedPoint(event));
	return;
	}
	else {
	return;
	}
	case SWT.MouseUp:
	if (this.started && event.button == 2) {
	this.started= false;
	updateCursor();
	return;
	}
	else {
	return;
	}
	case SWT.KeyDown:
	switch (event.keyCode) {
	case SWT.ARROW_DOWN:
	if (update(getVerticalBar(), RGraphicComposite.this.panIncrement)) {
	scrollV();
	}
	return;
	case SWT.ARROW_UP:
	if (update(getVerticalBar(), -RGraphicComposite.this.panIncrement)) {
	scrollV();
	}
	return;
	case SWT.ARROW_RIGHT:
	if (update(getHorizontalBar(), RGraphicComposite.this.panIncrement)) {
	scrollH();
	}
	return;
	case SWT.ARROW_LEFT:
	if (update(getHorizontalBar(), -RGraphicComposite.this.panIncrement)) {
	scrollH();
	}
	return;
	default:
	return;
	}
	}
	}

	private Point checkedPoint(final Event event) {
	if (event.item == RGraphicComposite.this) {
	return new Point(event.x, event.y);
	}
	else {
	final Point point= ((Control) event.widget).toDisplay(event.x, event.y);
	return RGraphicComposite.this.toControl(point);
	}
	}

	private void pan(final Point point) {
	if (update(getHorizontalBar(), this.startMouse.x - point.x)) {
	scrollH();
	}
	if (update(getVerticalBar(), this.startMouse.y - point.y)) {
	scrollV();
	}
	this.startMouse= point;
	}

	private boolean update(final ScrollBar bar, final int step) {
	if (bar != null && bar.isVisible()) {
	int selection= bar.getSelection() + step;
	if (selection < 0) {
	selection= 0;
	}
	else if (selection > bar.getMaximum()) {
	selection= bar.getMaximum() - bar.getThumb();
	}
	bar.setSelection(selection);
	return true;
	}
	return false;
	}

	}


	private static int checkStyle (final int style) {
	final int mask= SWT.H_SCROLL \| SWT.V_SCROLL \| SWT.BORDER \| SWT.LEFT_TO_RIGHT \| SWT.RIGHT_TO_LEFT;
	return style & mask;
	}


	private ERGraphic graphic;

	private RGraphicCanvas canvas;

	private int width= 0;
	private int height= 0;

	private boolean changedLayout;
	private boolean changedContent;

	private int panIncrement;
	private final PanListener panListener;

	private MouseListener locatorListener;


	public RGraphicComposite(final Composite parent, final ERGraphic graphic) {
	super(parent, checkStyle(SWT.H_SCROLL \| SWT.V_SCROLL));
	super.setLayout(new ScrolledCompositeLayout());

	this.panIncrement= 10;

	final ScrollBar hBar= getHorizontalBar();
	hBar.setVisible(false);
	hBar.addListener(SWT.Selection, new Listener() {
	@Override
	public void handleEvent(final Event event) {
	scrollH();
	}
	});
	hBar.setIncrement(this.panIncrement);
	final ScrollBar vBar= getVerticalBar();
	vBar.setVisible(false);
	vBar.addListener(SWT.Selection, new Listener() {
	@Override
	public void handleEvent(final Event event) {
	scrollV();
	}
	});
	vBar.setIncrement(this.panIncrement);
	addListener(SWT.Resize, new Listener() {
	@Override
	public void handleEvent(final Event event) {
	// checkContentSize();
	}
	});
	createCanvas();
	final Listener updateListener= new Listener() {
	@Override
	public void handleEvent(final Event event) {
	if (RGraphicComposite.this.changedContent) {
	updateGraphic();
	}
	}
	};
	addListener(SWT.Show, updateListener);
	addListener(SWT.Activate, updateListener);

	this.panListener= new PanListener();
	addListener(SWT.MouseDown, this.panListener);
	addListener(SWT.MouseMove, this.panListener);
	addListener(SWT.MouseExit, this.panListener);
	addListener(SWT.MouseUp, this.panListener);
	addListener(SWT.KeyDown, this.panListener);
	this.canvas.addListener(SWT.MouseDown, this.panListener);
	this.canvas.addListener(SWT.MouseMove, this.panListener);
	this.canvas.addListener(SWT.MouseExit, this.panListener);
	this.canvas.addListener(SWT.MouseUp, this.panListener);
	this.canvas.addListener(SWT.KeyDown, this.panListener);

	setGraphic(graphic);

	addDisposeListener(new DisposeListener() {
	@Override
	public void widgetDisposed(final DisposeEvent e) {
	disconnect();
	}
	});
	}

	private void createCanvas() {
	this.canvas= new RGraphicCanvas(this);
	}

	boolean needHBar(final Rectangle contentRect, final boolean vVisible) {
	final Rectangle hostRect= getBounds();
	hostRect.width-= 2 * getBorderWidth();
	if (vVisible) {
	hostRect.width-= getVerticalBar().getSize().x;
	}
	return (this.width > hostRect.width);
	}

	boolean needVBar(final Rectangle contentRect, final boolean hVisible) {
	final Rectangle hostRect= getBounds();
	hostRect.height-= 2 * getBorderWidth();
	if (hVisible) {
	hostRect.height-= getHorizontalBar().getSize().y;
	}
	return (this.height > hostRect.height);
	}

	private void scrollH() {
	final Point location= this.canvas.getLocation();
	final ScrollBar hBar= getHorizontalBar();
	if (hBar != null && hBar.isVisible()) {
	final int hSelection= hBar.getSelection();
	this.canvas.setLocation(-hSelection, location.y);
	}
	}

	private void scrollV() {
	final Point location= this.canvas.getLocation();
	final ScrollBar vBar= getVerticalBar();
	if (vBar != null && vBar.isVisible()) {
	final int vSelection= vBar.getSelection();
	this.canvas.setLocation(location.x, -vSelection);
	}
	}


	protected void disconnect() {
	if (this.graphic != null) {
	this.graphic.removeListener(this);
	}
	locatorStopped();
	}

	public void setGraphic(final ERGraphic graphic) {
	disconnect();

	this.graphic= graphic;
	if (this.graphic != null) {
	this.graphic.addListener(this);
	}

	instructionsChanged(true, null);

	if (this.graphic != null && this.graphic.isLocatorStarted()) {
	locatorStarted();
	}
	}

	/**
	* {@inheritDoc}
	* <p>
	* Note: No Layout can be set on this Control because it already
	* manages the size and position of its children.</p>
	*/
	@Override
	public void setLayout (final Layout layout) {
	checkWidget();
	return;
	}

	@Override
	public void activated() {
	}

	@Override
	public void deactivated() {
	}

	@Override
	public void drawingStarted() {
	}

	@Override
	public void instructionsChanged(final boolean reset, final List<ERGraphicInstruction> added) {
	this.changedContent= true;
	if (isVisible()) {
	updateGraphic();
	}
	}

	@Override
	public void drawingStopped() {
	}

	@Override
	public void locatorStarted() {
	if (this.locatorListener == null) {
	this.locatorListener= new MouseListener() {
	@Override
	public void mouseDown(final MouseEvent e) {
	switch (e.button) {
	case 1:
	RGraphicComposite.this.graphic.returnLocator(
	RGraphicComposite.this.canvas.widget2graphicsX(e.x), RGraphicComposite.this.canvas.widget2graphicY(e.y));
	break;
	case 3:
	RGraphicComposite.this.graphic.stopLocator(ERGraphic.LOCATOR_DONE);
	break;
	default:
	break;
	}
	}
	@Override
	public void mouseUp(final MouseEvent e) {
	}
	@Override
	public void mouseDoubleClick(final MouseEvent e) {
	}
	};
	this.canvas.addMouseListener(this.locatorListener);
	updateCursor();
	}
	}

	@Override
	public void locatorStopped() {
	if (this.locatorListener != null) {
	this.canvas.removeMouseListener(this.locatorListener);
	this.locatorListener= null;
	updateCursor();
	}
	}

	private void updateCursor() {
	if (this.panListener.started) {
	this.canvas.setCursor(Display.getCurrent().getSystemCursor(SWT.CURSOR_HAND));
	}
	else if (this.locatorListener != null) {
	this.canvas.setCursor(Display.getCurrent().getSystemCursor(SWT.CURSOR_CROSS));
	}
	else {
	this.canvas.setCursor(null);
	}
	}

	private void checkContentSize() {
	final Point size= this.canvas.computeSize(SWT.DEFAULT, SWT.DEFAULT);
	if (this.width == size.x && this.height == size.y) {
	return;
	}
	this.changedLayout= true;
	this.width= size.x;
	this.height= size.y;
	this.canvas.setSize(this.width, this.height);

	final ScrollBar hBar= getHorizontalBar();
	hBar.setMaximum(this.width);

	final ScrollBar vBar= getVerticalBar();
	vBar.setMaximum(this.height);
	layout(false);
	}


	public void redrawGraphic() {
	this.canvas.redraw();
	}

	private void updateGraphic() {
	this.changedContent= false;
	final List<? extends ERGraphicInstruction> instructions= (this.graphic != null) ?
	this.graphic.getInstructions() : RGraphicCanvas.NO_GRAPHIC;
	this.canvas.setInstructions(instructions);
	checkContentSize();
	this.canvas.redraw();
	}

	public double[] getGraphicFitSize() {
	final Rectangle bounds= getBounds();
	return new double[] { bounds.width, bounds.height };
	}

	public Control getControl() {
	return this;
	}

	/**
	* Returns the control on which the graphic is painted
	*
	* @since 1.0
	*/
	public Control getGraphicWidget() {
	return this.canvas;
	}

	/**
	* Converts a horizontal display coordinate of the {@link #getGraphicWidget() graphic widget}
	* to its graphic coordinate value.
	*
	* @since 1.0
	* @see ERGraphic Coordinate systems of R graphics
	*/
	public double convertWidget2GraphicX(final int x) {
	return this.canvas.widget2graphicsX(x);
	}

	/**
	* Converts a vertical display coordinate of the {@link #getGraphicWidget() graphic widget}
	* to its graphic coordinate value.
	*
	* @since 1.0
	* @see ERGraphic Coordinate systems of R graphics
	*/
	public double convertWidget2GraphicY(final int y) {
	return this.canvas.widget2graphicY(y);
	}

	}