Have TalkBack announce results and formula changes
Bug: 21048155
Bug: 19189356
Incrementally announce additions to the formula.
Explicitly announce result after hitting equals.
Announce when display is cleared.
Remove old FIXME comment after a bit more testing.
Change-Id: I836ff6672de3f891888b2724470290c8721d4fcf
diff --git a/src/com/android/calculator2/CalculatorText.java b/src/com/android/calculator2/CalculatorText.java
index b0bbb7c..4b0b0c9 100644
--- a/src/com/android/calculator2/CalculatorText.java
+++ b/src/com/android/calculator2/CalculatorText.java
@@ -204,6 +204,39 @@
return lastFitTextSize;
}
+ private static boolean startsWith(CharSequence whole, CharSequence prefix) {
+ int wholeLen = whole.length();
+ int prefixLen = prefix.length();
+ if (prefixLen > wholeLen) {
+ return false;
+ }
+ for (int i = 0; i < prefixLen; ++i) {
+ if (prefix.charAt(i) != whole.charAt(i)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ /**
+ * Functionally equivalent to setText(), but explicitly announce changes.
+ * If the new text is an extension of the old one, announce the addition.
+ * Otherwise, e.g. after deletion, announce the entire new text.
+ */
+ public void changeTextTo(CharSequence newText) {
+ CharSequence oldText = getText();
+ if (startsWith(newText, oldText)) {
+ int newLen = newText.length();
+ int oldLen = oldText.length();
+ if (oldLen != newLen) {
+ announceForAccessibility(newText.subSequence(oldLen, newLen));
+ }
+ } else {
+ announceForAccessibility(newText);
+ }
+ setText(newText);
+ }
+
public boolean stopActionMode() {
if (mActionMode != null) {
mActionMode.finish();