Java tutorial
/* * Copyright (c) 2010, 2017, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javafx.scene.shape; import com.sun.javafx.geom.BaseBounds; import com.sun.javafx.geom.Ellipse2D; import com.sun.javafx.geom.transform.BaseTransform; import com.sun.javafx.scene.DirtyBits; import com.sun.javafx.scene.NodeHelper; import com.sun.javafx.scene.shape.CircleHelper; import com.sun.javafx.scene.shape.ShapeHelper; import com.sun.javafx.sg.prism.NGCircle; import com.sun.javafx.sg.prism.NGNode; import com.sun.javafx.sg.prism.NGShape; import javafx.beans.property.DoubleProperty; import javafx.beans.property.DoublePropertyBase; import javafx.scene.Node; import javafx.scene.paint.Paint; /** * The {@code Circle} class creates a new circle * with the specified radius and center location measured in pixels. * <p> * Example usage. The following code creates a circle with radius of 50 pixels * centered at (100,100). * </p> * <pre>{@code import javafx.scene.shape.Circle; Circle circle = new Circle(); circle.setCenterX(100.0f); circle.setCenterY(100.0f); circle.setRadius(50.0f); }</pre> * @since JavaFX 2.0 */ public class Circle extends Shape { static { CircleHelper.setCircleAccessor(new CircleHelper.CircleAccessor() { @Override public NGNode doCreatePeer(Node node) { return ((Circle) node).doCreatePeer(); } @Override public void doUpdatePeer(Node node) { ((Circle) node).doUpdatePeer(); } @Override public BaseBounds doComputeGeomBounds(Node node, BaseBounds bounds, BaseTransform tx) { return ((Circle) node).doComputeGeomBounds(bounds, tx); } @Override public com.sun.javafx.geom.Shape doConfigShape(Shape shape) { return ((Circle) shape).doConfigShape(); } }); } private final Ellipse2D shape = new Ellipse2D(); { // To initialize the class helper at the begining each constructor of this class CircleHelper.initHelper(this); } /** * Creates a new instance of Circle with a specified radius. * @param radius the radius of the circle in pixels */ public Circle(double radius) { setRadius(radius); } /** * Creates a new instance of Circle with a specified radius and fill. * @param radius the radius of the circle * @param fill determines how to fill the interior of the Circle */ public Circle(double radius, Paint fill) { setRadius(radius); setFill(fill); } /** * Creates an empty instance of Circle. */ public Circle() { } /** * Creates a new instance of Circle with a specified position and radius. * @param centerX the horizontal position of the center of the circle in pixels * @param centerY the vertical position of the center of the circle in pixels * @param radius the radius of the circle in pixels */ public Circle(double centerX, double centerY, double radius) { setCenterX(centerX); setCenterY(centerY); setRadius(radius); } /** * Creates a new instance of Circle with a specified position, radius and fill. * @param centerX the horizontal position of the center of the circle in pixels * @param centerY the vertical position of the center of the circle in pixels * @param radius the radius of the circle in pixels * @param fill determines how to fill the interior of the Circle */ public Circle(double centerX, double centerY, double radius, Paint fill) { setCenterX(centerX); setCenterY(centerY); setRadius(radius); setFill(fill); } /** * Defines the horizontal position of the center of the circle in pixels. * * @defaultValue 0.0 */ private DoubleProperty centerX; public final void setCenterX(double value) { if (centerX != null || value != 0.0) { centerXProperty().set(value); } } public final double getCenterX() { return centerX == null ? 0.0 : centerX.get(); } public final DoubleProperty centerXProperty() { if (centerX == null) { centerX = new DoublePropertyBase(0.0) { @Override public void invalidated() { NodeHelper.markDirty(Circle.this, DirtyBits.NODE_GEOMETRY); NodeHelper.geomChanged(Circle.this); } @Override public Object getBean() { return Circle.this; } @Override public String getName() { return "centerX"; } }; } return centerX; } /** * Defines the vertical position of the center of the circle in pixels. * * @defaultValue 0.0 */ private DoubleProperty centerY; public final void setCenterY(double value) { if (centerY != null || value != 0.0) { centerYProperty().set(value); } } public final double getCenterY() { return centerY == null ? 0.0 : centerY.get(); } public final DoubleProperty centerYProperty() { if (centerY == null) { centerY = new DoublePropertyBase(0.0) { @Override public void invalidated() { NodeHelper.markDirty(Circle.this, DirtyBits.NODE_GEOMETRY); NodeHelper.geomChanged(Circle.this); } @Override public Object getBean() { return Circle.this; } @Override public String getName() { return "centerY"; } }; } return centerY; } /** * Defines the radius of the circle in pixels. * * @defaultValue 0.0 */ private final DoubleProperty radius = new DoublePropertyBase() { @Override public void invalidated() { NodeHelper.markDirty(Circle.this, DirtyBits.NODE_GEOMETRY); NodeHelper.geomChanged(Circle.this); } @Override public Object getBean() { return Circle.this; } @Override public String getName() { return "radius"; } }; public final void setRadius(double value) { radius.set(value); } public final double getRadius() { return radius.get(); } public final DoubleProperty radiusProperty() { return radius; } /** */ @Override StrokeLineJoin convertLineJoin(StrokeLineJoin t) { // The MITER join style can produce anomalous results for very thin or // very wide ellipses when the bezier curves that approximate the arcs // become so distorted that they shoot out MITER-like extensions. This // effect complicates matters because it makes the circles very non-round, // and also because it means we might have to pad the bounds to account // for this rare and unpredictable circumstance. // To avoid the problem, we set the Join style to BEVEL for any // circle. The BEVEL join style is more predictable for // anomalous angles and is the simplest join style to compute in // the stroking code. // These problems do not necessarily happen for circles which have a // fixed and balanced aspect ratio, but why waste time computing a // conversion of a MITER join style when it has no advantage for // circles and technically requires more computation? return StrokeLineJoin.BEVEL; } /* * Note: This method MUST only be called via its accessor method. */ private NGNode doCreatePeer() { return new NGCircle(); } /* * Note: This method MUST only be called via its accessor method. */ private BaseBounds doComputeGeomBounds(BaseBounds bounds, BaseTransform tx) { // if there is no fill or stroke, then there are no bounds. The bounds // must be marked empty in this case to distinguish it from 0,0,0,0 // which would actually contribute to the bounds of a group. if (getMode() == NGShape.Mode.EMPTY) { return bounds.makeEmpty(); } final double cX = getCenterX(); final double cY = getCenterY(); if ((tx.getType() & ~(BaseTransform.TYPE_MASK_ROTATION | BaseTransform.TYPE_TRANSLATION)) == 0) { double tCX = cX * tx.getMxx() + cY * tx.getMxy() + tx.getMxt(); double tCY = cX * tx.getMyx() + cY * tx.getMyy() + tx.getMyt(); double r = getRadius(); if (getMode() != NGShape.Mode.FILL && getStrokeType() != StrokeType.INSIDE) { double upad = getStrokeWidth(); if (getStrokeType() == StrokeType.CENTERED) { upad /= 2.0f; } r += upad; } return bounds.deriveWithNewBounds((float) (tCX - r), (float) (tCY - r), 0, (float) (tCX + r), (float) (tCY + r), 0); } else if ((tx.getType() & ~(BaseTransform.TYPE_MASK_SCALE | BaseTransform.TYPE_TRANSLATION | BaseTransform.TYPE_FLIP)) == 0) { final double r = getRadius(); final double x = getCenterX() - r; final double y = getCenterY() - r; final double width = 2.0 * r; final double height = width; double upad; if (getMode() == NGShape.Mode.FILL || getStrokeType() == StrokeType.INSIDE) { upad = 0.0f; } else { upad = getStrokeWidth(); } return computeBounds(bounds, tx, upad, 0, x, y, width, height); } return computeShapeBounds(bounds, tx, ShapeHelper.configShape(this)); } /* * Note: This method MUST only be called via its accessor method. */ private Ellipse2D doConfigShape() { double r = getRadius(); shape.setFrame((float) (getCenterX() - r), // x (float) (getCenterY() - r), // y (float) (r * 2.0), // w (float) (r * 2.0)); // h return shape; } /* * Note: This method MUST only be called via its accessor method. */ private void doUpdatePeer() { if (NodeHelper.isDirty(this, DirtyBits.NODE_GEOMETRY)) { final NGCircle peer = NodeHelper.getPeer(this); peer.updateCircle((float) getCenterX(), (float) getCenterY(), (float) getRadius()); } } /** * Returns a string representation of this {@code Circle} object. * @return a string representation of this {@code Circle} object. */ @Override public String toString() { final StringBuilder sb = new StringBuilder("Circle["); String id = getId(); if (id != null) { sb.append("id=").append(id).append(", "); } sb.append("centerX=").append(getCenterX()); sb.append(", centerY=").append(getCenterY()); sb.append(", radius=").append(getRadius()); sb.append(", fill=").append(getFill()); Paint stroke = getStroke(); if (stroke != null) { sb.append(", stroke=").append(stroke); sb.append(", strokeWidth=").append(getStrokeWidth()); } return sb.append("]").toString(); } }