Changeset 7170 in josm for trunk/src/org/openstreetmap

Timestamp:

2014-05-22T20:55:57+02:00 (11 years ago)

Author:

simon04

Message:

fix #10063 - MapCSS: make min() and max() work on a list as well

For instance, max(split(";", tag(widths))) splits the tag widths on semicolons and determines the largest numeric value

Location:

trunk/src/org/openstreetmap/josm

Files:

• gui/mappaint/mapcss/ExpressionFactory.java (modified) (5 diffs)
• tools/Predicates.java (modified) (2 diffs)

trunk/src/org/openstreetmap/josm/gui/mappaint/mapcss/ExpressionFactory.java

@@ -15 +15 @@
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 import java.util.regex.Matcher;
@@ -29 +31 @@
 import org.openstreetmap.josm.io.XmlWriter;
 import org.openstreetmap.josm.tools.ColorHelper;
+import org.openstreetmap.josm.tools.Predicates;
 import org.openstreetmap.josm.tools.Utils;
 
@@ -210 +213 @@
 
         /**
-         * Returns the minimum of the given numbers, or NaN if no number is given.
-         * @see Math#min(float, float)
-         */
-        public static float min(float... args) {
-            if (args.length == 0) {
-                return Float.NaN;
-            } else if (args.length == 1) {
-                return args[0];
-            } else {
-                float min = Math.min(args[0], args[1]);
-                for (int i = 2; i < args.length; i++) {
-                    min = Math.min(min, args[i]);
-                }
-                return min;
-            }
-        }
-
-        /**
-         * Returns the maximum of the given numbers, or NaN if no number is given.
-         * @see Math#max(float, float)
-         */
-        public static float max(float... args) {
-            if (args.length == 0) {
-                return Float.NaN;
-            } else if (args.length == 1) {
-                return args[0];
-            } else {
-                float max = Math.max(args[0], args[1]);
-                for (int i = 2; i < args.length; i++) {
-                    max = Math.max(max, args[i]);
-                }
-                return max;
-            }
-        }
-
-        /**
          * Splits string {@code toSplit} at occurrences of the separator string {@code sep} and returns a list of matches.
          * @see String#split(String)
@@ -673 +640 @@
         else if ("length".equals(name) && args.size() == 1)
             return new LengthFunction(args.get(0));
+        else if ("max".equals(name) && !args.isEmpty())
+            return new MinMaxFunction(args, true);
+        else if ("min".equals(name) && !args.isEmpty())
+            return new MinMaxFunction(args, false);
 
         for (Method m : arrayFunctions) {
@@ -795 +766 @@
                 return s.length();
             return null;
+        }
+    }
+
+    /**
+     * Computes the maximum/minimum value an arbitrary number of floats, or a list of floats.
+     */
+    public static class MinMaxFunction implements Expression {
+
+        private final List<Expression> args;
+        private final boolean computeMax;
+
+        public MinMaxFunction(final List<Expression> args, final boolean computeMax) {
+            this.args = args;
+            this.computeMax = computeMax;
+        }
+
+        public Float aggregateList(List<?> lst) {
+            final List<Float> floats = Utils.transform(lst, new Utils.Function<Object, Float>() {
+                @Override
+                public Float apply(Object x) {
+                    return Cascade.convertTo(x, float.class);
+                }
+            });
+            final Collection<Float> nonNullList = Utils.filter(floats, Predicates.not(Predicates.isNull()));
+            return computeMax ? Collections.max(nonNullList) : Collections.min(nonNullList);
+        }
+
+        @Override
+        public Object evaluate(final Environment env) {
+            List<?> l = Cascade.convertTo(args.get(0).evaluate(env), List.class);
+            if (args.size() != 1 || l == null)
+                l = Utils.transform(args, new Utils.Function<Expression, Object>() {
+                    @Override
+                    public Object apply(Expression x) {
+                        return x.evaluate(env);
+                    }
+                });
+            return aggregateList(l);
         }
     }

trunk/src/org/openstreetmap/josm/tools/Predicates.java

@@ -28 +28 @@
 
     /**
-     * Returns a {@link Predicate} executing {@link Utils#equal}.
+     * Returns a {@link Predicate} executing {@link Objects#equals}.
      */
     public static <T> Predicate<T> equalTo(final T ref) {
@@ -110 +110 @@
         };
     }
+
+    /**
+     * Returns a {@link Predicate} testing whether objects are {@code null}.
+     */
+    public static <T> Predicate<T> isNull() {
+        return new Predicate<T>() {
+            @Override
+            public boolean evaluate(T object) {
+                return object == null;
+            }
+        };
+    }
 }