added showChoiceBox, closes #1094

fxgl-samples/src/main/java/intermediate/DialogsSample.java

@@ -37,6 +37,11 @@ protected void initUI() {
 
         dialogs.put("Error", () -> getDialogService().showErrorBox("This is a scary error box!", () -> {}));
 
+        dialogs.put("Choice with 1", () -> getDialogService().showChoiceBox("Choose wisely!", answer -> System.out.println("Chosen: " + answer), "Hello"));
+        dialogs.put("Choice with 2", () -> getDialogService().showChoiceBox("Choose wisely!", answer -> System.out.println("Chosen: " + answer), "Hello", "World"));
+        dialogs.put("Choice with 3", () -> getDialogService().showChoiceBox("Choose wisely!", answer -> System.out.println("Chosen: " + answer), "Hello", "World", "FXGL"));
+        dialogs.put("Choice with 4", () -> getDialogService().showChoiceBox("Choose wisely!", answer -> System.out.println("Chosen: " + answer), "Hello", "World", "FXGL", "JavaFX"));
+
         dialogs.put("Confirmation", () -> getDialogService().showConfirmationBox("This is a confirmation box. Agree?", answer -> System.out.println("You pressed yes? " + answer)));
 
         dialogs.put("Input", () -> getDialogService().showInputBox("This is an input box. You can type stuff...", answer -> System.out.println("You typed: "+ answer)));

fxgl-scene/src/main/java/com/almasb/fxgl/ui/DialogFactoryService.java

@@ -26,6 +26,8 @@ public abstract class DialogFactoryService extends EngineService {
 
     public abstract Pane confirmationDialog(String message, Consumer<Boolean> callback);
 
+    public abstract <T> Pane choiceDialog(String message, Consumer<T> resultCallback, T firstOption, T... options);
+
     public abstract Pane inputDialog(String message, Consumer<String> callback);
 
     public abstract Pane inputDialog(String message, Predicate<String> filter, Consumer<String> callback);

fxgl-scene/src/main/java/com/almasb/fxgl/ui/DialogService.java

@@ -47,6 +47,18 @@ public abstract class DialogService extends EngineService {
      */
     public abstract void showConfirmationBox(String message, Consumer<Boolean> resultCallback);
 
+    /**
+     * Shows a blocking message box with given choices.
+     * The callback is invoked with the user answer as parameter.
+     *
+     * @param message message to show
+     * @param resultCallback the function to be called
+     * @param firstOption the first option
+     * @param options any other options
+     * @param <T> type of options
+     */
+    public abstract <T> void showChoiceBox(String message, Consumer<T> resultCallback, T firstOption, T... options);
+
     /**
      * Shows a blocking (stops game execution, method returns normally) message box with OK button and input field. The callback
      * is invoked with the field text as parameter.

fxgl-scene/src/main/kotlin/com/almasb/fxgl/ui/FXGLDialogFactoryServiceProvider.kt

@@ -11,6 +11,7 @@ import com.almasb.fxgl.localization.LocalizationService
 import javafx.beans.binding.StringBinding
 import javafx.beans.property.ReadOnlyDoubleProperty
 import javafx.beans.value.ChangeListener
+import javafx.collections.FXCollections
 import javafx.geometry.Insets
 import javafx.geometry.Pos
 import javafx.scene.Node
@@ -89,6 +90,46 @@ class FXGLDialogFactoryServiceProvider : DialogFactoryService() {
         return wrap(vbox)
     }
 
+    override fun <T : Any> choiceDialog(message: String, resultCallback: Consumer<T>, firstOption: T, vararg options: T): Pane {
+        val text = createMessage(message)
+
+        val choices = options.toMutableList()
+        choices.add(0, firstOption)
+
+        val hbox = HBox()
+
+        if (choices.size > 3) {
+
+            val choiceBox = uiFactory.newChoiceBox(FXCollections.observableArrayList(choices))
+            choiceBox.selectionModel.selectFirst()
+
+            val btn = uiFactory.newButton("Select")
+            btn.setOnAction {
+                resultCallback.accept(choiceBox.value)
+            }
+
+            hbox.children += choiceBox
+            hbox.children += btn
+
+        } else {
+            choices.forEach { option ->
+                val btn = uiFactory.newButton(option.toString())
+                btn.setOnAction {
+                    resultCallback.accept(option)
+                }
+
+                hbox.children += btn
+            }
+        }
+
+        hbox.alignment = Pos.CENTER
+
+        val vbox = VBox(50.0, text, hbox)
+        vbox.setAlignment(Pos.CENTER)
+
+        return wrap(vbox)
+    }
+
     override fun inputDialog(message: String, callback: Consumer<String>): Pane {
         return inputDialog(message, Predicate { true }, callback)
     }

fxgl/src/main/kotlin/com/almasb/fxgl/app/services/FXGLDialogService.kt

@@ -133,6 +133,15 @@ class FXGLDialogService : DialogService() {
         show("Confirm", dialog)
     }
 
+    override fun <T : Any> showChoiceBox(message: String, callback: Consumer<T>, firstOption: T, vararg options: T) {
+        val dialog = dialogFactory.choiceDialog(message, { result ->
+            close()
+            callback.accept(result)
+        }, firstOption, *options)
+
+        show("Choice", dialog)
+    }
+
     override fun showInputBox(message: String, resultCallback: Consumer<String>) {
         showInputBox(message, Predicate { true }, resultCallback)
     }

fxgl/src/test/kotlin/com/almasb/fxgl/app/MockDialogService.kt

@@ -28,6 +28,9 @@ object MockDialogService : DialogService() {
     override fun showConfirmationBox(message: String?, resultCallback: Consumer<Boolean>?) {
     }
 
+    override fun <T : Any?> showChoiceBox(message: String?, resultCallback: Consumer<T>?, firstOption: T, vararg options: T) {
+    }
+
     override fun showInputBoxWithCancel(message: String?, filter: Predicate<String>?, resultCallback: Consumer<String>?) {
     }