Avoid duplicate requireResult() calls, add checking
Bug: 33011774
Don't needlessly cancel a previous requireResult() call. In addition to
wasting resources, this results in an onCancelled() call that set
the state back to INPUT, with surprising UI results.
If requireResult() is called before the corresponding CalculatorResult
is measured, crash with a stack trace. That seems to be an easy mistake.
Delete code that used to make things kind of work if we ran without
a correct display size.
Delay requireResult call that used to occur during onCreate().
Arrange to get the right listener invoked when the onLayout
requireResult() call completes.
Change-Id: I5da4855bfdda27fca5abc5871c4b312ef6ebede0
diff --git a/src/com/android/calculator2/Evaluator.java b/src/com/android/calculator2/Evaluator.java
index a37a44a..8ea518f 100644
--- a/src/com/android/calculator2/Evaluator.java
+++ b/src/com/android/calculator2/Evaluator.java
@@ -151,6 +151,7 @@
* the supplied string prefix.
* The prefix consists of the first len characters of string s, which is presumed to
* represent a whole number. Callable from non-UI thread.
+ * Returns zero if metrics information is not yet available.
*/
public float separatorChars(String s, int len);
/**
@@ -282,8 +283,8 @@
mVal = new AtomicReference<UnifiedReal>();
}
- // Currently running expression evaluator, if any. This is an AsyncEvaluator if
- // mVal.get() == null, an AsyncReevaluator otherwise.
+ // Currently running expression evaluator, if any. This is either an AsyncEvaluator
+ // (if mResultString == null or it's obsolete), or an AsyncReevaluator.
public AsyncTask mEvaluator;
// The remaining fields are valid only if an evaluation completed successfully.
@@ -449,7 +450,7 @@
*/
class AsyncEvaluator extends AsyncTask<Void, Void, InitialResult> {
private boolean mDm; // degrees
- private boolean mRequired; // Result was requested by user.
+ public boolean mRequired; // Result was requested by user.
private boolean mQuiet; // Suppress cancellation message.
private Runnable mTimeoutRunnable = null;
private EvaluationListener mListener; // Completion callback.
@@ -1123,8 +1124,13 @@
* Start optional evaluation of expression and display when ready.
* @param index of expression to be evaluated.
* Can quietly time out without a listener callback.
+ * No-op if cmi.getMaxChars() == 0.
*/
public void evaluateAndNotify(long index, EvaluationListener listener, CharMetricsInfo cmi) {
+ if (cmi.getMaxChars() == 0) {
+ // Probably shouldn't happen. If it does, we didn't promise to do anything anyway.
+ return;
+ }
if (index == MAIN_INDEX) {
if (mMainExpr.mResultString != null && !mChangedValue) {
// Already done. Just notify.
@@ -1141,13 +1147,22 @@
* Start required evaluation of expression at given index and call back listener when ready.
* If index is MAIN_INDEX, we may also directly display a timeout message.
* Uses longer timeouts than optional evaluation.
+ * Requires cmi.getMaxChars() != 0.
*/
public void requireResult(long index, EvaluationListener listener, CharMetricsInfo cmi) {
+ if (cmi.getMaxChars() == 0) {
+ throw new AssertionError("requireResult called too early");
+ }
ExprInfo ei = ensureExprIsCached(index);
if (ei.mResultString == null || (index == MAIN_INDEX && mChangedValue)) {
- // Restart evaluator in requested mode, i.e. with longer timeout.
- cancel(ei, true);
- evaluateResult(index, listener, cmi, true);
+ if ((ei.mEvaluator instanceof AsyncEvaluator)
+ && ((AsyncEvaluator)(ei.mEvaluator)).mRequired) {
+ // Duplicate request; ignore.
+ } else {
+ // Restart evaluator in requested mode, i.e. with longer timeout.
+ cancel(ei, true);
+ evaluateResult(index, listener, cmi, true);
+ }
} else {
notifyImmediately(index, ei, listener, cmi);
}