001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.gui.mappaint.styleelement;
003
004import java.awt.Color;
005import java.awt.Rectangle;
006import java.awt.geom.Point2D;
007import java.util.Objects;
008
009import org.openstreetmap.josm.data.osm.IPrimitive;
010import org.openstreetmap.josm.data.osm.Node;
011import org.openstreetmap.josm.data.osm.visitor.paint.MapPaintSettings;
012import org.openstreetmap.josm.data.osm.visitor.paint.PaintColors;
013import org.openstreetmap.josm.data.osm.visitor.paint.StyledMapRenderer;
014import org.openstreetmap.josm.gui.mappaint.Cascade;
015import org.openstreetmap.josm.gui.mappaint.Environment;
016import org.openstreetmap.josm.gui.mappaint.Keyword;
017import org.openstreetmap.josm.gui.mappaint.MultiCascade;
018import org.openstreetmap.josm.tools.CheckParameterUtil;
019
020/**
021 * Text style attached to a style with a bounding box, like an icon or a symbol.
022 */
023public class BoxTextElement extends StyleElement {
024
025    /**
026     * MapCSS text-anchor-horizontal
027     */
028    public enum HorizontalTextAlignment {
029        /**
030         * Align to the left
031         */
032        LEFT,
033        /**
034         * Align in the center
035         */
036        CENTER,
037        /**
038         * Align to the right
039         */
040        RIGHT
041    }
042
043    /**
044     * MapCSS text-anchor-vertical
045     */
046    public enum VerticalTextAlignment {
047        /**
048         * Render above the box
049         */
050        ABOVE,
051        /**
052         * Align to the top of the box
053         */
054        TOP,
055        /**
056         * Render at the center of the box
057         */
058        CENTER,
059        /**
060         * Align to the bottom of the box
061         */
062        BOTTOM,
063        /**
064         * Render below the box
065         */
066        BELOW
067    }
068
069    /**
070     * Something that provides us with a {@link BoxProviderResult}
071     * @since 10600 (functional interface)
072     */
073    @FunctionalInterface
074    public interface BoxProvider {
075        /**
076         * Compute and get the {@link BoxProviderResult}. The temporary flag is set if the result of the computation may change in the future.
077         * @return The result of the computation.
078         */
079        BoxProviderResult get();
080    }
081
082    /**
083     * A box rectangle with a flag if it is temporary.
084     */
085    public static class BoxProviderResult {
086        private final Rectangle box;
087        private final boolean temporary;
088
089        /**
090         * Create a new box provider result
091         * @param box The box
092         * @param temporary The temporary flag, will be returned by {@link #isTemporary()}
093         */
094        public BoxProviderResult(Rectangle box, boolean temporary) {
095            this.box = box;
096            this.temporary = temporary;
097        }
098
099        /**
100         * Returns the box.
101         * @return the box
102         */
103        public Rectangle getBox() {
104            return box;
105        }
106
107        /**
108         * Determines if the box can change in future calls of the {@link BoxProvider#get()} method
109         * @return {@code true} if the box can change in future calls of the {@code BoxProvider#get()} method
110         */
111        public boolean isTemporary() {
112            return temporary;
113        }
114    }
115
116    /**
117     * A {@link BoxProvider} that always returns the same non-temporary rectangle
118     */
119    public static class SimpleBoxProvider implements BoxProvider {
120        private final Rectangle box;
121
122        /**
123         * Constructs a new {@code SimpleBoxProvider}.
124         * @param box the box
125         */
126        public SimpleBoxProvider(Rectangle box) {
127            this.box = box;
128        }
129
130        @Override
131        public BoxProviderResult get() {
132            return new BoxProviderResult(box, false);
133        }
134
135        @Override
136        public int hashCode() {
137            return Objects.hash(box);
138        }
139
140        @Override
141        public boolean equals(Object obj) {
142            if (this == obj) return true;
143            if (obj == null || getClass() != obj.getClass()) return false;
144            SimpleBoxProvider that = (SimpleBoxProvider) obj;
145            return Objects.equals(box, that.box);
146        }
147    }
148
149    /**
150     * The default style a simple node should use for it's text
151     */
152    public static final BoxTextElement SIMPLE_NODE_TEXT_ELEMSTYLE;
153    static {
154        MultiCascade mc = new MultiCascade();
155        Cascade c = mc.getOrCreateCascade("default");
156        c.put(TEXT, Keyword.AUTO);
157        Node n = new Node();
158        n.put("name", "dummy");
159        SIMPLE_NODE_TEXT_ELEMSTYLE = create(new Environment(n, mc, "default", null), NodeElement.SIMPLE_NODE_ELEMSTYLE.getBoxProvider());
160        if (SIMPLE_NODE_TEXT_ELEMSTYLE == null) throw new AssertionError();
161    }
162
163    /**
164     * Caches the default text color from the preferences.
165     *
166     * FIXME: the cache isn't updated if the user changes the preference during a JOSM
167     * session. There should be preference listener updating this cache.
168     */
169    private static volatile Color defaultTextColorCache;
170
171    /**
172     * The text this element should display.
173     */
174    public TextLabel text;
175    /**
176     * The x offset of the text.
177     */
178    public int xOffset;
179    /**
180     * The y offset of the text. In screen space (inverted to user space)
181     */
182    public int yOffset;
183    /**
184     * The {@link HorizontalTextAlignment} for this text.
185     */
186    public HorizontalTextAlignment hAlign;
187    /**
188     * The {@link VerticalTextAlignment} for this text.
189     */
190    public VerticalTextAlignment vAlign;
191    protected BoxProvider boxProvider;
192
193    /**
194     * Create a new {@link BoxTextElement}
195     * @param c The current cascade
196     * @param text The text to display
197     * @param boxProvider The box provider to use
198     * @param offsetX x offset, in screen space
199     * @param offsetY y offset, in screen space
200     * @param hAlign The {@link HorizontalTextAlignment}
201     * @param vAlign The {@link VerticalTextAlignment}
202     */
203    public BoxTextElement(Cascade c, TextLabel text, BoxProvider boxProvider,
204            int offsetX, int offsetY, HorizontalTextAlignment hAlign, VerticalTextAlignment vAlign) {
205        super(c, 5f);
206        xOffset = offsetX;
207        yOffset = offsetY;
208        CheckParameterUtil.ensureParameterNotNull(text);
209        CheckParameterUtil.ensureParameterNotNull(hAlign);
210        CheckParameterUtil.ensureParameterNotNull(vAlign);
211        this.text = text;
212        this.boxProvider = boxProvider;
213        this.hAlign = hAlign;
214        this.vAlign = vAlign;
215    }
216
217    /**
218     * Create a new {@link BoxTextElement} with a boxprovider and a box.
219     * @param env The MapCSS environment
220     * @param boxProvider The box provider.
221     * @return A new {@link BoxTextElement} or <code>null</code> if the creation failed.
222     */
223    public static BoxTextElement create(Environment env, BoxProvider boxProvider) {
224        initDefaultParameters();
225
226        TextLabel text = TextLabel.create(env, defaultTextColorCache, false);
227        if (text == null) return null;
228        // Skip any primitives that don't have text to draw. (Styles are recreated for any tag change.)
229        // The concrete text to render is not cached in this object, but computed for each
230        // repaint. This way, one BoxTextElement object can be used by multiple primitives (to save memory).
231        if (text.labelCompositionStrategy.compose(env.osm) == null) return null;
232
233        Cascade c = env.mc.getCascade(env.layer);
234
235        HorizontalTextAlignment hAlign;
236        switch (c.get(TEXT_ANCHOR_HORIZONTAL, Keyword.RIGHT, Keyword.class).val) {
237            case "left":
238                hAlign = HorizontalTextAlignment.LEFT;
239                break;
240            case "center":
241                hAlign = HorizontalTextAlignment.CENTER;
242                break;
243            case "right":
244            default:
245                hAlign = HorizontalTextAlignment.RIGHT;
246        }
247        VerticalTextAlignment vAlign;
248        switch (c.get(TEXT_ANCHOR_VERTICAL, Keyword.BOTTOM, Keyword.class).val) {
249            case "above":
250                vAlign = VerticalTextAlignment.ABOVE;
251                break;
252            case "top":
253                vAlign = VerticalTextAlignment.TOP;
254                break;
255            case "center":
256                vAlign = VerticalTextAlignment.CENTER;
257                break;
258            case "below":
259                vAlign = VerticalTextAlignment.BELOW;
260                break;
261            case "bottom":
262            default:
263                vAlign = VerticalTextAlignment.BOTTOM;
264        }
265        Point2D offset = TextLabel.getTextOffset(c);
266
267        return new BoxTextElement(c, text, boxProvider, (int) offset.getX(), (int) -offset.getY(), hAlign, vAlign);
268    }
269
270    /**
271     * Get the box in which the content should be drawn.
272     * @return The box.
273     */
274    public Rectangle getBox() {
275        return boxProvider.get().getBox();
276    }
277
278    private static void initDefaultParameters() {
279        if (defaultTextColorCache != null) return;
280        defaultTextColorCache = PaintColors.TEXT.get();
281    }
282
283    @Override
284    public void paintPrimitive(IPrimitive osm, MapPaintSettings settings, StyledMapRenderer painter,
285            boolean selected, boolean outermember, boolean member) {
286        if (osm instanceof Node) {
287            painter.drawBoxText((Node) osm, this);
288        }
289    }
290
291    @Override
292    public boolean equals(Object obj) {
293        if (this == obj) return true;
294        if (obj == null || getClass() != obj.getClass()) return false;
295        if (!super.equals(obj)) return false;
296        BoxTextElement that = (BoxTextElement) obj;
297        return hAlign == that.hAlign &&
298               vAlign == that.vAlign &&
299               xOffset == that.xOffset &&
300               yOffset == that.yOffset &&
301               Objects.equals(text, that.text) &&
302               Objects.equals(boxProvider, that.boxProvider);
303    }
304
305    @Override
306    public int hashCode() {
307        return Objects.hash(super.hashCode(), text, boxProvider, hAlign, vAlign, xOffset, yOffset);
308    }
309
310    @Override
311    public String toString() {
312        return "BoxTextElement{" + super.toString() + ' ' + text.toStringImpl()
313                + " box=" + getBox() + " hAlign=" + hAlign + " vAlign=" + vAlign + " xOffset=" + xOffset + " yOffset=" + yOffset + '}';
314    }
315}