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1   /**********************************************
2    * Copyright (C) 2010 Lukas Laag
3    * This file is part of lib-gwt-svg.
4    * 
5    * libgwtsvg is free software: you can redistribute it and/or modify
6    * it under the terms of the GNU Lesser General Public License as published by
7    * the Free Software Foundation, either version 3 of the License, or
8    * (at your option) any later version.
9    * 
10   * libgwtsvg is distributed in the hope that it will be useful,
11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13   * GNU Lesser General Public License for more details.
14   * 
15   * You should have received a copy of the GNU Lesser General Public License
16   * along with libgwtsvg.  If not, see http://www.gnu.org/licenses/
17   **********************************************/
18  /*
19   * Copyright (c) 2004 World Wide Web Consortium,
20   *
21   * (Massachusetts Institute of Technology, European Research Consortium for
22   * Informatics and Mathematics, Keio University). All Rights Reserved. This
23   * work is distributed under the W3C(r) Software License [1] in the hope that
24   * it will be useful, but WITHOUT ANY WARRANTY; without even the implied
25   * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
26   *
27   * [1] http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231
28   */
29  
30  package org.vectomatic.dom.svg.impl;
31  
32  import org.vectomatic.dom.svg.OMSVGAnimatedBoolean;
33  import org.vectomatic.dom.svg.OMSVGAnimatedLength;
34  import org.vectomatic.dom.svg.OMSVGAnimatedTransformList;
35  import org.vectomatic.dom.svg.OMSVGMatrix;
36  import org.vectomatic.dom.svg.OMSVGPoint;
37  import org.vectomatic.dom.svg.OMSVGRect;
38  import org.vectomatic.dom.svg.OMSVGStringList;
39  
40  import com.google.gwt.core.client.JavaScriptException;
41  
42  /**
43   * The {@link org.vectomatic.dom.svg.impl.SVGLineElement} interface corresponds
44   * to the <a href='http://www.w3.org/TR/SVG11/shapes.html#LineElement' title='line
45   * element specification'>line</a> element.
46   */
47  public class SVGLineElement extends SVGElement {
48    protected SVGLineElement() {
49    }
50  
51    // Implementation of the svg::SVGLineElement W3C IDL interface
52    /**
53     * Corresponds to attribute {@link org.vectomatic.dom.svg.impl.SVGLineElement#getX1()}
54     * on the given <a href='http://www.w3.org/TR/SVG11/shapes.html#LineElement'
55     * title='line element specification'>line</a> element.
56     */
57    public final native OMSVGAnimatedLength getX1() /*-{
58      return this.x1;
59    }-*/;
60    /**
61     * Corresponds to attribute {@link org.vectomatic.dom.svg.impl.SVGLineElement#getY1()}
62     * on the given <a href='http://www.w3.org/TR/SVG11/shapes.html#LineElement'
63     * title='line element specification'>line</a> element.
64     */
65    public final native OMSVGAnimatedLength getY1() /*-{
66      return this.y1;
67    }-*/;
68    /**
69     * Corresponds to attribute {@link org.vectomatic.dom.svg.impl.SVGLineElement#getX2()}
70     * on the given <a href='http://www.w3.org/TR/SVG11/shapes.html#LineElement'
71     * title='line element specification'>line</a> element.
72     */
73    public final native OMSVGAnimatedLength getX2() /*-{
74      return this.x2;
75    }-*/;
76    /**
77     * Corresponds to attribute {@link org.vectomatic.dom.svg.impl.SVGLineElement#getY2()}
78     * on the given <a href='http://www.w3.org/TR/SVG11/shapes.html#LineElement'
79     * title='line element specification'>line</a> element.
80     */
81    public final native OMSVGAnimatedLength getY2() /*-{
82      return this.y2;
83    }-*/;
84  
85    // Implementation of the svg::SVGExternalResourcesRequired W3C IDL interface
86    /**
87     * Corresponds to attribute {@link org.vectomatic.dom.svg.itf.ISVGExternalResourcesRequired#getExternalResourcesRequired()}
88     * on the given element. Note that the SVG DOM defines the attribute {@link
89     * org.vectomatic.dom.svg.itf.ISVGExternalResourcesRequired#getExternalResourcesRequired()}
90     * as being of type {@link org.vectomatic.dom.svg.OMSVGAnimatedBoolean}, whereas
91     * the SVG language definition says that {@link org.vectomatic.dom.svg.itf.ISVGExternalResourcesRequired#getExternalResourcesRequired()}
92     * is not animated. Because the SVG language definition states that {@link
93     * org.vectomatic.dom.svg.itf.ISVGExternalResourcesRequired#getExternalResourcesRequired()}
94     * cannot be animated, the {@link org.vectomatic.dom.svg.OMSVGAnimatedBoolean#getAnimVal()}
95     * will always be the same as the {@link org.vectomatic.dom.svg.OMSVGAnimatedBoolean#getBaseVal()}.
96     */
97    public final native OMSVGAnimatedBoolean getExternalResourcesRequired() /*-{
98      return this.externalResourcesRequired;
99    }-*/;
100 
101   // Implementation of the svg::SVGLangSpace W3C IDL interface
102   /**
103    * Corresponds to attribute <code>xml:lang</code> on the given element.
104    */
105   public final native String getXmllang() /*-{
106     return this.xmllang;
107   }-*/;
108   /**
109    * Corresponds to attribute <code>xml:lang</code> on the given element.
110    * @throws DOMException(NO_MODIFICATION_ALLOWED_ERR) Raised on an   attempt
111    * to change the value of a <a href="svgdom.html#ReadOnlyNodes">read only
112    * attribute</a>.
113    */
114   public final native void setXmllang(String value) throws JavaScriptException /*-{
115     this.xmllang = value;
116   }-*/;
117   /**
118    * Corresponds to attribute <code>xml:space</code> on the given element.
119    */
120   public final native String getXmlspace() /*-{
121     return this.xmlspace;
122   }-*/;
123   /**
124    * Corresponds to attribute <code>xml:space</code> on the given element.
125    * @throws DOMException(NO_MODIFICATION_ALLOWED_ERR) Raised on an   attempt
126    * to change the value of a <a href="svgdom.html#ReadOnlyNodes">read only
127    * attribute</a>.
128    */
129   public final native void setXmlspace(String value) throws JavaScriptException /*-{
130     this.xmlspace = value;
131   }-*/;
132 
133   // Implementation of the svg::SVGLocatable W3C IDL interface
134   /**
135    * The element which established the current viewport. Often, the nearest
136    * ancestor <a href='http://www.w3.org/TR/SVG11/struct.html#SVGElement' title='svg
137    * element specification'>svg</a> element. Null if the current element is
138    * the outermost <a href='http://www.w3.org/TR/SVG11/struct.html#SVGElement'
139    * title='svg element specification'>svg</a> element.
140    */
141   public final native SVGElement getNearestViewportElement() /*-{
142     return this.nearestViewportElement;
143   }-*/;
144   /**
145    * The farthest ancestor <a href='http://www.w3.org/TR/SVG11/struct.html#SVGElement'
146    * title='svg element specification'>svg</a> element. Null if the current
147    * element is the outermost <a href='http://www.w3.org/TR/SVG11/struct.html#SVGElement'
148    * title='svg element specification'>svg</a> element.
149    */
150   public final native SVGElement getFarthestViewportElement() /*-{
151     return this.farthestViewportElement;
152   }-*/;
153   /**
154    * Returns the tight bounding box in current user space (i.e., after application
155    * of the <code>transform</code> attribute, if any) on the geometry of all
156    * contained graphics elements, exclusive of stroking, clipping, masking and
157    * filter effects). Note that getBBox must return the actual bounding box
158    * at the time the method was called, even in case the element has not yet
159    * been rendered.
160    * @return An {@link org.vectomatic.dom.svg.OMSVGRect} object that defines
161    * the bounding box.
162    */
163   public final native OMSVGRect getBBox() /*-{
164     return this.getBBox();
165   }-*/;
166   /**
167    * Returns the transformation matrix from current user units (i.e., after
168    * application of the <code>transform</code> attribute, if any) to the viewport
169    * coordinate system for the {@link org.vectomatic.dom.svg.itf.ISVGLocatable#getNearestViewportElement()}.
170    * @return An {@link org.vectomatic.dom.svg.OMSVGMatrix} object that defines
171    * the CTM.
172    */
173   public final native OMSVGMatrix getCTM() /*-{
174     return this.getCTM();
175   }-*/;
176   /**
177    * Returns the transformation matrix from current user units (i.e., after
178    * application of the <code>transform</code> attribute, if any) to the parent
179    * user agent's notice of a "pixel". For display devices, ideally this represents
180    * a physical screen pixel. For other devices or environments where physical
181    * pixel sizes are not known, then an algorithm similar to the CSS2 definition
182    * of a "pixel" can be used instead.  Note that null is returned if this element
183    * is not hooked into the document tree. This method would have been more
184    * aptly named as <code>getClientCTM</code>, but the name <code>getScreenCTM</code>
185    * is kept for historical reasons.
186    * @return An {@link org.vectomatic.dom.svg.OMSVGMatrix} object that defines
187    * the given   transformation matrix.
188    */
189   public final native OMSVGMatrix getScreenCTM() /*-{
190     return this.getScreenCTM();
191   }-*/;
192   /**
193    * Returns the transformation matrix from the user coordinate system on the
194    * current element (after application of the <code>transform</code> attribute,
195    * if any) to the user coordinate system on parameter <var>element</var> (after
196    * application of its <code>transform</code> attribute, if any).
197    * @param element The target element.
198    * @return An {@link org.vectomatic.dom.svg.OMSVGMatrix} object that defines
199    * the transformation.
200    * @throws SVGException(SVG_MATRIX_NOT_INVERTABLE) Raised if the currently
201    * defined transformation matrices make it impossible to compute the   given
202    * matrix (e.g., because one of the transformations is singular).
203    */
204   public final native OMSVGMatrix getTransformToElement(SVGElement element) throws JavaScriptException /*-{
205     return this.getTransformToElement(element);
206   }-*/;
207 
208   // Implementation of the svg::SVGTests W3C IDL interface
209   /**
210    * Corresponds to attribute {@link org.vectomatic.dom.svg.itf.ISVGTests#getRequiredFeatures()}
211    * on the given element.
212    */
213   public final native OMSVGStringList getRequiredFeatures() /*-{
214     return @org.vectomatic.dom.svg.OMNode::convertList(Lcom/google/gwt/core/client/JavaScriptObject;)(this.requiredFeatures);
215   }-*/;
216   /**
217    * Corresponds to attribute {@link org.vectomatic.dom.svg.itf.ISVGTests#getRequiredExtensions()}
218    * on the given element.
219    */
220   public final native OMSVGStringList getRequiredExtensions() /*-{
221     return @org.vectomatic.dom.svg.OMNode::convertList(Lcom/google/gwt/core/client/JavaScriptObject;)(this.requiredExtensions);
222   }-*/;
223   /**
224    * Corresponds to attribute {@link org.vectomatic.dom.svg.itf.ISVGTests#getSystemLanguage()}
225    * on the given element.
226    */
227   public final native OMSVGStringList getSystemLanguage() /*-{
228     return @org.vectomatic.dom.svg.OMNode::convertList(Lcom/google/gwt/core/client/JavaScriptObject;)(this.systemLanguage);
229   }-*/;
230   /**
231    * Returns true if the user agent supports the given extension, specified
232    * by a URI.
233    * @param extension The name of the extension, expressed as a URI.
234    * @return True or false, depending on whether the given extension is   supported.
235    */
236   public final native boolean hasExtension(String extension) /*-{
237     return this.hasExtension(extension);
238   }-*/;
239 
240   // Implementation of the svg::SVGTransformable W3C IDL interface
241   /**
242    * Corresponds to attribute {@link org.vectomatic.dom.svg.itf.ISVGTransformable#getTransform()}
243    * on the given element.
244    */
245   public final native OMSVGAnimatedTransformList getTransform() /*-{
246     return this.transform;
247   }-*/;
248 
249   // Helper methods
250   /**
251    * Computes the intersection point between this line and the tangent
252    * perpendicular to this line through p. The intersection is
253    * returned in parametric form. If one considers the parametric
254    * equation of this line to be: 
255    * <pre>P = P1 + t * (P2 - P1)</pre>
256    * then this method returns the value of t at the intersection point.
257    * @param p The point which defines the tangent.
258    * @return the parametric value of the intersection point.
259    */
260   public final native float parametricIntersection(OMSVGPoint p) /*-{
261   	var x1 = this.x1.baseVal.value;
262   	var y1 = this.y1.baseVal.value;
263   	var x2 = this.x2.baseVal.value;
264   	var y2 = this.y2.baseVal.value;
265 	var dx = x2 - x1;
266 	var dy = y2 - y1;
267 	return ((p.x - x1)*(x2 - x1) + (p.y - y1)*(y2 - y1))/(dx * dx + dy * dy);
268   }-*/;
269   /**
270    * Computes the intersection point between this line and the tangent
271    * perpendicular to this line through p. 
272    * @param p The point which defines the tangent.
273    * @return the intersection point.
274    */
275   public final OMSVGPoint intersectionPoint(OMSVGPoint p) {
276 	OMSVGPoint destination = getOwnerSVGElement().createSVGPoint();
277     return intersectionPoint(p,destination);
278   }
279   /**
280    * Computes the intersection point between this line and the tangent
281    * perpendicular to this line through p and puts the
282    * result in the specified destination point.
283    * @param p The point which defines the tangent.
284    * @param destination The point where to store the result.
285    * @return the intersection point.
286    */
287   public final OMSVGPoint intersectionPoint(OMSVGPoint p, OMSVGPoint destination) {
288     float u = parametricIntersection(p);
289     float x1 = getX1().getBaseVal().getValue();
290     float y1 = getY1().getBaseVal().getValue();
291     float x2 = getX2().getBaseVal().getValue();
292     float y2 = getY2().getBaseVal().getValue();
293     float dx = x2 - x1;
294     float dy = y2 - y1;
295     destination.setX(x1 + u * dx);
296     destination.setY(y1 + u * dy);
297     return destination;
298   }
299   /**
300    * Computes the distance from the specified point to this line.
301    * @param p A point in the plane
302    * @return the distance to this line.
303    */
304   public final float distanceToLine(OMSVGPoint p) {
305 	return p.distance(intersectionPoint(p));
306   }
307 }