Add startWith and startAt to TapTargetSequence (KeepSafe#228)

Previously it was cumbersome to restore state in a TapTargetSequence after rotation due to the fact that you needed to manually modify the list of targets you pass in to get back to your desired target. Now the class supports starting from a specified target id or position in the queue, allowing callers to keep a static list of targets for their sequence.
sotcha · Nov 19, 2017 · 6898f18 · 6898f18
1 parent ddf5ea0
commit 6898f18
Showing 1 changed file with 40 additions and 0 deletions.
diff --git a/taptargetview/src/main/java/com/getkeepsafe/taptargetview/TapTargetSequence.java b/taptargetview/src/main/java/com/getkeepsafe/taptargetview/TapTargetSequence.java
@@ -126,6 +126,46 @@ public void start() {
     showNext();
   }
 
+  /** Immediately starts the sequence from the given targetId's position in the queue */
+  public void startWith(int targetId) {
+    if (active) {
+      return;
+    }
+
+    while (targets.peek() != null && targets.peek().id() != targetId) {
+      targets.poll();
+    }
+
+    TapTarget peekedTarget = targets.peek();
+    if (peekedTarget == null || peekedTarget.id() != targetId) {
+      throw new IllegalStateException("Given target " + targetId + " not in sequence");
+    }
+
+    start();
+  }
+
+  /** Immediately starts the sequence at the specified zero-based index in the queue */
+  public void startAt(int index) {
+    if (active) {
+      return;
+    }
+
+    if (index < 0 || index >= targets.size()) {
+      throw new IllegalArgumentException("Given invalid index " + index);
+    }
+
+    final int expectedSize = targets.size() - index;
+    while (targets.peek() != null && targets.size() != expectedSize) {
+      targets.poll();
+    }
+
+    if (targets.size() != expectedSize) {
+      throw new IllegalStateException("Given index " + index + " not in sequence");
+    }
+
+    start();
+  }
+
   /**
    * Cancels the sequence, if the current target is cancelable.
    * When the sequence is canceled, the current target is dismissed and the remaining targets are