Ability to pause and seek animation

app/src/main/java/com/annimon/hotarufx/ui/controller/EditorController.java

@@ -34,6 +34,7 @@ import javafx.scene.control.TitledPane;
 import javafx.scene.layout.Pane;
 import javafx.stage.Modality;
 import javafx.stage.Stage;
+import javafx.util.Duration;
 import lombok.val;
 import org.fxmisc.richtext.CodeArea;
 import org.fxmisc.richtext.LineNumberFactory;
@@ -157,7 +158,17 @@ public class EditorController implements Initializable, DocumentListener {
         stage.initOwner(primaryStage);
         stage.initModality(Modality.WINDOW_MODAL);
         stage.setScene(composition.produceAnimationScene());
-        composition.getTimeline().getFxTimeline().play();
+        val timeline = composition.getTimeline();
+        timeline.getFxTimeline().currentTimeProperty().addListener((o, oldValue, d) -> {
+            val min = (int) d.toMinutes();
+            val durationSec = d.subtract(Duration.minutes(min));
+            val sec = (int) durationSec.toSeconds();
+            val durationMs = durationSec.subtract(Duration.seconds(sec));
+            val frame = (int) (durationMs.toMillis() * timeline.getFrameRate() / 1000d);
+            val allFrame = (int) (d.toMillis() * timeline.getFrameRate() / 1000d);
+            stage.setTitle(String.format("%02d:%02d.%02d   %d", min, sec, frame, allFrame));
+        });
+        stage.setOnShown(e -> timeline.getFxTimeline().play());
         stage.show();
     }
 

app/src/main/java/com/annimon/hotarufx/visual/Composition.java

@@ -2,6 +2,7 @@ package com.annimon.hotarufx.visual;
 
 import javafx.scene.Group;
 import javafx.scene.Scene;
+import javafx.scene.input.KeyCode;
 import javafx.scene.paint.Color;
 import javafx.scene.paint.Paint;
 import lombok.Getter;
@@ -62,6 +63,30 @@ public class Composition {
     }
 
     public Scene produceAnimationScene() {
-        return new Scene(scene.getGroup(), sceneWidth, sceneHeight, background);
+        val fxScene = new Scene(scene.getGroup(), sceneWidth, sceneHeight, background);
+        fxScene.setOnKeyPressed(e -> {
+            switch (e.getCode()) {
+                case SPACE:
+                    timeline.togglePause();
+                    break;
+                case BACK_SPACE:
+                    timeline.getFxTimeline().playFromStart();
+                    break;
+                case LEFT:
+                case RIGHT:
+                    int sign = e.getCode() == KeyCode.LEFT ? -1 : 1;
+                    if (e.isShiftDown()) {
+                        timeline.seek(sign);
+                    } else if (e.isControlDown()) {
+                        timeline.seek(10 * sign);
+                    } else if (e.isAltDown()) {
+                        timeline.seek(30 * sign);
+                    } else {
+                        timeline.seekFrame(sign);
+                    }
+                    break;
+            }
+        });
+        return fxScene;
     }
 }

app/src/main/java/com/annimon/hotarufx/visual/TimeLine.java

@@ -4,6 +4,7 @@ import javafx.animation.KeyValue;
 import javafx.animation.Timeline;
 import javafx.util.Duration;
 import lombok.Getter;
+import lombok.val;
 
 public class TimeLine {
 
@@ -26,4 +27,31 @@ public class TimeLine {
     private Duration duration(KeyFrame keyFrame) {
         return Duration.millis(1000d * keyFrame.getFrame() / frameRate);
     }
+
+    public void togglePause() {
+        switch (fxTimeline.getStatus()) {
+            case PAUSED:
+                fxTimeline.play();
+                break;
+            case RUNNING:
+                fxTimeline.pause();
+                break;
+            case STOPPED:
+                fxTimeline.playFromStart();
+                break;
+        }
+    }
+
+    public void seekFrame(final int value) {
+        fxTimeline.pause();
+        val offset = Duration.millis(1000d * Math.abs(value) / frameRate);
+        val now = fxTimeline.getCurrentTime();
+        val newDuration = value > 0 ? now.add(offset) : now.subtract(offset);
+        fxTimeline.jumpTo(newDuration);
+    }
+
+    public void seek(final int sec) {
+        val now = fxTimeline.getCurrentTime();
+        fxTimeline.jumpTo(now.add(Duration.seconds(sec)));
+    }
 }