| /******************************************************************************* |
| * Copyright (c) 2003, 2010 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.gef; |
| |
| import org.eclipse.draw2d.geometry.Dimension; |
| import org.eclipse.draw2d.geometry.Point; |
| import org.eclipse.draw2d.geometry.PrecisionRectangle; |
| |
| /** |
| * A helper used to perform snapping to a grid, which is specified on the |
| * graphical viewer via the various properties defined in this class. This |
| * helper can be used in conjunction with the |
| * {@link org.eclipse.gef.tools.DragEditPartsTracker DragEditPartsTracker} when |
| * dragging editparts within a graphical viewer. When snapping a rectangle, the |
| * edges of the rectangle will snap along gridlines. |
| * <P> |
| * This helper does not keep up with changes made to the graphical viewer's |
| * properties. Clients should instantiate a new helper each time one is |
| * requested and not hold on to instances of the helper, if the grid properties |
| * specified on the viewer are subject to change. |
| * |
| * @author Randy Hudson |
| * @author Pratik Shah |
| * @since 3.0 |
| * @see org.eclipse.gef.editparts.GridLayer |
| */ |
| public class SnapToGrid extends SnapToHelper { |
| |
| /** |
| * A viewer property indicating whether the snap function is enabled. The |
| * value must be a Boolean. |
| */ |
| public static final String PROPERTY_GRID_ENABLED = "SnapToGrid.isEnabled"; //$NON-NLS-1$ |
| |
| /** |
| * A viewer property indicating whether the grid should be displayed. The |
| * value must be a Boolean. |
| */ |
| public static final String PROPERTY_GRID_VISIBLE = "SnapToGrid.isVisible"; //$NON-NLS-1$ |
| /** |
| * A viewer property indicating the grid spacing. The value must be a |
| * {@link Dimension}. |
| */ |
| public static final String PROPERTY_GRID_SPACING = "SnapToGrid.GridSpacing"; //$NON-NLS-1$ |
| /** |
| * A viewer property indicating the grid's origin. The value must be a |
| * {@link Point}. |
| */ |
| public static final String PROPERTY_GRID_ORIGIN = "SnapToGrid.GridOrigin"; //$NON-NLS-1$ |
| |
| /** |
| * The default grid size if the viewer does not specify a size. |
| * |
| * @see #PROPERTY_GRID_SPACING |
| */ |
| public static final int DEFAULT_GRID_SIZE = 12; |
| |
| /** |
| * @deprecated use DEFAULT_GRID_SIZE |
| */ |
| public static final int DEFAULT_GAP = DEFAULT_GRID_SIZE; |
| |
| /** |
| * The graphical part whose content's figure defines the grid. |
| */ |
| protected GraphicalEditPart container; |
| |
| /** |
| * The horizontal interval for the grid |
| */ |
| protected int gridX; |
| |
| /** |
| * The vertical interval for the grid |
| */ |
| protected int gridY; |
| |
| /** |
| * The origin of the grid. |
| */ |
| protected Point origin; |
| |
| /** |
| * Constructs a gridded snap helper on the given editpart. The editpart |
| * should be the graphical editpart whose contentspane figure is used as the |
| * reference for the grid. |
| * |
| * @param container |
| * the editpart which the grid is on |
| */ |
| public SnapToGrid(GraphicalEditPart container) { |
| this.container = container; |
| Dimension spacing = (Dimension) container.getViewer().getProperty( |
| PROPERTY_GRID_SPACING); |
| if (spacing != null) { |
| gridX = spacing.width; |
| gridY = spacing.height; |
| } |
| if (gridX == 0) |
| gridX = DEFAULT_GRID_SIZE; |
| if (gridY == 0) |
| gridY = DEFAULT_GRID_SIZE; |
| Point loc = (Point) container.getViewer().getProperty( |
| PROPERTY_GRID_ORIGIN); |
| if (loc != null) |
| origin = loc; |
| else |
| origin = new Point(); |
| } |
| |
| /** |
| * @see SnapToHelper#snapRectangle(Request, int, PrecisionRectangle, |
| * PrecisionRectangle) |
| */ |
| public int snapRectangle(Request request, int snapLocations, |
| PrecisionRectangle rect, PrecisionRectangle result) { |
| |
| rect = rect.getPreciseCopy(); |
| makeRelative(container.getContentPane(), rect); |
| PrecisionRectangle correction = new PrecisionRectangle(); |
| makeRelative(container.getContentPane(), correction); |
| |
| if (gridX > 0 && (snapLocations & EAST) != 0) { |
| correction.setPreciseWidth(correction.preciseWidth() |
| - Math.IEEEremainder(rect.preciseRight() - origin.x - 1, |
| gridX)); |
| snapLocations &= ~EAST; |
| } |
| |
| if ((snapLocations & (WEST | HORIZONTAL)) != 0 && gridX > 0) { |
| double leftCorrection = Math.IEEEremainder(rect.preciseX() |
| - origin.x, gridX); |
| correction.setPreciseX(correction.preciseX() - leftCorrection); |
| if ((snapLocations & HORIZONTAL) == 0) { |
| correction.setPreciseWidth(correction.preciseWidth() |
| + leftCorrection); |
| } |
| snapLocations &= ~(WEST | HORIZONTAL); |
| } |
| |
| if ((snapLocations & SOUTH) != 0 && gridY > 0) { |
| correction.setPreciseHeight(correction.preciseHeight() |
| - Math.IEEEremainder(rect.preciseBottom() - origin.y - 1, |
| gridY)); |
| snapLocations &= ~SOUTH; |
| } |
| |
| if ((snapLocations & (NORTH | VERTICAL)) != 0 && gridY > 0) { |
| double topCorrection = Math.IEEEremainder(rect.preciseY() |
| - origin.y, gridY); |
| correction.setPreciseY(correction.preciseY() - topCorrection); |
| if ((snapLocations & VERTICAL) == 0) { |
| correction.setPreciseHeight(correction.preciseHeight() |
| + topCorrection); |
| } |
| snapLocations &= ~(NORTH | VERTICAL); |
| } |
| |
| makeAbsolute(container.getContentPane(), correction); |
| result.setPreciseX(result.preciseX() + correction.preciseX()); |
| result.setPreciseY(result.preciseY() + correction.preciseY()); |
| result.setPreciseWidth(result.preciseWidth() |
| + correction.preciseWidth()); |
| result.setPreciseHeight(result.preciseHeight() |
| + correction.preciseHeight()); |
| return snapLocations; |
| } |
| |
| } |