CATROID-766 Evaluate “when touches actor or object” to false initially

Evaluating “when …”  always to false at the start of a scene, allows an object to change 
its position before checking for a collision.

Since all objects are placed at coordinates (0, 0) initially,  when a scene is started or restarted, for the first 200 milliseconds, the condition “when …” is not checked and the value false is returned instead. After this time threshold has been completed, a scene is considered to be continued and hence, the condition at this point onwards is always evaluated to check for a collision.

catroid/src/main/java/org/catrobat/catroid/content/ConditionScriptTrigger.java

@@ -23,6 +23,7 @@
 
 package org.catrobat.catroid.content;
 
+import android.os.SystemClock;
 import android.util.Log;
 
 import org.catrobat.catroid.ProjectManager;
@@ -45,6 +46,13 @@ public class ConditionScriptTrigger {
 	static final int ALREADY_TRIGGERED = 1;
 	private static final String TAG = ConditionScriptTrigger.class.getSimpleName();
 
+	private boolean sceneFirstStart = false;
+	private boolean sceneRestarted = false;
+	private boolean sceneAlreadyStarted = false;
+
+	private long startTime = 0;
+	static final long EVALUATE_AND_TRIGGER_ACTIONS_THRESHOLD = 200;
+
 	@TriggerStatus
 	private int status = TRIGGER_NOW;
 	private final Formula formula;
@@ -56,7 +64,28 @@ public class ConditionScriptTrigger {
 	void evaluateAndTriggerActions(Sprite sprite) {
 		try {
 			Scope scope = new Scope(ProjectManager.getInstance().getCurrentProject(), sprite, null);
-			boolean conditionValue = formula.interpretBoolean(scope);
+			boolean conditionValue = false;
+
+			if (sceneFirstStart || sceneRestarted) {
+				if (startTime == 0) {
+					startTime = SystemClock.uptimeMillis();
+				} else {
+					long elapsedTime = SystemClock.uptimeMillis() - startTime;
+
+					if (elapsedTime >= EVALUATE_AND_TRIGGER_ACTIONS_THRESHOLD) {
+						if (sceneFirstStart) {
+							sceneFirstStart = false;
+						} else if (sceneRestarted) {
+							sceneRestarted = false;
+						}
+						startTime = 0;
+						conditionValue = formula.interpretBoolean(scope);
+					}
+				}
+			} else {
+				conditionValue = formula.interpretBoolean(scope);
+			}
+
 			if (conditionValue) {
 				triggerScript(sprite);
 			} else {
@@ -75,6 +104,19 @@ private void triggerScript(Sprite sprite) {
 		}
 	}
 
+	public void updateSceneFirstStart() {
+		sceneFirstStart = true;
+		sceneAlreadyStarted = true;
+	}
+
+	public void resetStartTimeIfSceneRestarted() {
+		if (sceneAlreadyStarted) {
+			startTime = 0;
+			sceneRestarted = true;
+			sceneFirstStart = false;
+		}
+	}
+
 	@Override
 	public boolean equals(Object o) {
 		if (this == o) {

catroid/src/main/java/org/catrobat/catroid/content/Sprite.java

@@ -42,12 +42,15 @@
 import org.catrobat.catroid.content.actions.ScriptSequenceAction;
 import org.catrobat.catroid.content.bricks.Brick;
 import org.catrobat.catroid.content.bricks.FormulaBrick;
+import org.catrobat.catroid.content.bricks.IfLogicBeginBrick;
+import org.catrobat.catroid.content.bricks.IfThenLogicBeginBrick;
 import org.catrobat.catroid.content.bricks.PlaySoundBrick;
 import org.catrobat.catroid.content.bricks.UserDefinedBrick;
 import org.catrobat.catroid.content.bricks.WhenConditionBrick;
 import org.catrobat.catroid.content.eventids.EventId;
 import org.catrobat.catroid.embroidery.RunningStitch;
 import org.catrobat.catroid.formulaeditor.Formula;
+import org.catrobat.catroid.formulaeditor.FormulaElement;
 import org.catrobat.catroid.formulaeditor.UserData;
 import org.catrobat.catroid.formulaeditor.UserList;
 import org.catrobat.catroid.formulaeditor.UserVariable;
@@ -364,12 +367,53 @@ public void initConditionScriptTriggers() {
 		for (Script script : scriptList) {
 			if (script instanceof WhenConditionScript) {
 				WhenConditionBrick conditionBrick = (WhenConditionBrick) script.getScriptBrick();
-				Formula condition = conditionBrick.getFormulaWithBrickField(Brick.BrickField.IF_CONDITION);
-				conditionScriptTriggers.add(new ConditionScriptTrigger(condition));
+				Formula formula = conditionBrick.getFormulaWithBrickField(Brick.BrickField.IF_CONDITION);
+				ConditionScriptTrigger conditionScriptTrigger = new ConditionScriptTrigger(formula);
+
+				if (waitBeforeCheckingCollision(formula)) {
+					conditionScriptTrigger.updateSceneFirstStart();
+				}
+				conditionScriptTriggers.add(conditionScriptTrigger);
+			}
+		}
+	}
+
+	public void resetConditionScriptTriggers() {
+		for (ConditionScriptTrigger conditionScriptTrigger : conditionScriptTriggers) {
+			conditionScriptTrigger.resetStartTimeIfSceneRestarted();
+		}
+	}
+
+	public void initIfConditionBrickTriggers() {
+		for (Script script : scriptList) {
+			if (!script.getBrickList().isEmpty()) {
+				Brick brick = script.getBrickList().get(0);
+
+				if (brick instanceof IfThenLogicBeginBrick) {
+					for (Formula formula : ((IfThenLogicBeginBrick) brick).getFormulas()) {
+						if (waitBeforeCheckingCollision(formula)) {
+							formula.sceneFirstStart(true);
+						}
+					}
+				} else if (brick instanceof IfLogicBeginBrick) {
+					for (Formula formula : ((IfLogicBeginBrick) brick).getFormulas()) {
+						if (waitBeforeCheckingCollision(formula)) {
+							formula.sceneFirstStart(true);
+						}
+					}
+				}
 			}
 		}
 	}
 
+	boolean waitBeforeCheckingCollision(Formula formula) {
+		boolean wait = false;
+		if (formula.getRoot() != null) {
+			wait = formula.getRoot().getElementType() == FormulaElement.ElementType.COLLISION_FORMULA;
+		}
+		return wait;
+	}
+
 	void evaluateConditionScriptTriggers() {
 		for (ConditionScriptTrigger conditionScriptTrigger : conditionScriptTriggers) {
 			conditionScriptTrigger.evaluateAndTriggerActions(this);

catroid/src/main/java/org/catrobat/catroid/formulaeditor/Formula.java

@@ -43,6 +43,8 @@ public class Formula implements Serializable {
 
 	private transient InternFormula internFormula = null;
 
+	private boolean sceneFirstStart = false;
+
 	public Formula(FormulaElement formulaElement) {
 		formulaTree = formulaElement;
 		internFormula = new InternFormula(formulaTree.getInternTokenList());
@@ -132,7 +134,12 @@ public Integer interpretInteger(Scope scope) throws InterpretationException {
 
 	public Double interpretDouble(Scope scope) throws InterpretationException {
 		try {
-			return assertNotNaN(interpretDoubleInternal(scope));
+			if (sceneFirstStart) {
+				sceneFirstStart = false;
+				return 0.0;
+			} else {
+				return assertNotNaN(interpretDoubleInternal(scope));
+			}
 		} catch (ClassCastException | NumberFormatException exception) {
 			throw new InterpretationException("Couldn't interpret Formula.", exception);
 		}
@@ -255,4 +262,8 @@ private String toLocalizedString(boolean value, StringProvider stringProvider) {
 	public interface StringProvider {
 		String getTrueOrFalse(Boolean value);
 	}
+
+	public void sceneFirstStart(boolean sceneFirstStart) {
+		this.sceneFirstStart = sceneFirstStart;
+	}
 }

catroid/src/main/java/org/catrobat/catroid/stage/StageListener.java

@@ -199,6 +199,8 @@ public void create() {
 		physicsWorld = scene.resetPhysicsWorld();
 		sprites = new ArrayList<>(scene.getSpriteList());
 
+		resetConditionScriptTriggers();
+
 		embroideryPatternManager = new DSTPatternManager();
 		initActors(sprites);
 
@@ -208,6 +210,12 @@ public void create() {
 		axes = new Texture(Gdx.files.internal("stage/red_pixel.bmp"));
 	}
 
+	private void resetConditionScriptTriggers() {
+		for (Sprite sprite : sprites) {
+			sprite.resetConditionScriptTriggers();
+		}
+	}
+
 	public void setPaused(boolean paused) {
 		this.paused = paused;
 	}
@@ -538,6 +546,7 @@ public void render() {
 			for (Sprite sprite : sprites) {
 				sprite.initializeEventThreads(EventId.START);
 				sprite.initConditionScriptTriggers();
+				sprite.initIfConditionBrickTriggers();
 				if (!sprite.getLookList().isEmpty()) {
 					sprite.look.setLookData(sprite.getLookList().get(0));
 				}