(refactor) Use Java 8 Streams, not Guava

[JordanMartinez]

No description provided.

[JordanMartinez]

Note: There is still one section of guava code because I wasn't sure how to implement the method correctly:

private static <T> Set<T> combine(T input,
                                  Collection<Function<T, Set<T>>> functions) {
    return FluentIterable.from(functions)
        .transformAndConcat((f) -> f.apply(input))
        .toSet();
}

[brcolow]

Hmm..I am not too familiar with the Guava libraries and FluentIterable in particular.

But maybe something like this?

import java.util.Collection;
import java.util.Set;
import java.util.function.Function;
import java.util.stream.Collectors;

    private static <T> Set<T> combine(T input, Collection<Function<T, Set<T>>> functions) {
        return functions.stream().map(function ->  function.apply(input)).flatMap(Collection::stream)
                .collect(Collectors.toSet());
    }

[JordanMartinez]

Your code is correct, but the issue is that Collectors.toSet() does not care about the returned order of items in the returned set. Thus, the test that checks this method (assertThat(results, contains(label0, label1, ... button0, button1)) fails because contains checks order as well as contents. This can be resolved if containsInAnyOrder was used instead, but is that desired? Is order important?

[brcolow]

Hmmm...are the "leaf-nodes" of the scene-graph in a well defined order? If so, then I guess order does matter and we could add a sort call. If the "leaf-nodes" of the scene-graph are not in a well-defined order, then containsInAnyOrder is more appropriate.

[brcolow]

What I mean is, are the circled nodes in a well-defined order?

[JordanMartinez]

Yes, they seem to be in a well-defined order.

This is what the FXML looks like:

<StackPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="200.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1">
   <children>
      <VBox prefHeight="200.0" prefWidth="100.0">
         <children>
            <HBox fx:id="labels" spacing="20.0">
               <children>
                  <Label fx:id="label0" text="0" />
                  <Label fx:id="label1" text="1" />
                  <Label fx:id="label2" text="2" />
               </children>
               <padding>
                  <Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
               </padding>
            </HBox>
            <HBox fx:id="buttons" spacing="10.0">
               <padding>
                  <Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
               </padding>
               <children>
                  <Button fx:id="button0" mnemonicParsing="false" text="0" />
                  <Button fx:id="button1" mnemonicParsing="false" text="1" />
                  <Button fx:id="button2" mnemonicParsing="false" text="2" />
               </children>
            </HBox>

[brcolow]

Maybe http://stackoverflow.com/questions/27611896/is-there-a-collector-that-collects-to-an-order-preserving-set is relevant?

[JordanMartinez]

Still failed... :-/

I'll have to look into it another time. It's getting late.

[JordanMartinez]

Fixed it. It works if I use a LinkedHashSet instead of a HashSet

[brcolow]

Thanks! Merged.