Merge "Detect cases where rotation messes with initialization"

java/src/com/android/inputmethod/latin/Constants.java

@@ -138,6 +138,9 @@ public final class Constants {
     public static final int SPELL_CHECKER_COORDINATE = -3;
     public static final int EXTERNAL_KEYBOARD_COORDINATE = -4;
 
+    // A hint on how many characters to cache from the TextView. A good value of this is given by
+    // how many characters we need to be able to almost always find the caps mode.
+    public static final int EDITOR_CONTENTS_CACHE_SIZE = 1024;
 
     // Must be equal to MAX_WORD_LENGTH in native/jni/src/defines.h
     public static final int DICTIONARY_MAX_WORD_LENGTH = 48;

java/src/com/android/inputmethod/latin/LatinIME.java

@@ -233,6 +233,7 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
         private static final int MSG_RESUME_SUGGESTIONS = 4;
         private static final int MSG_REOPEN_DICTIONARIES = 5;
         private static final int MSG_ON_END_BATCH_INPUT = 6;
+        private static final int MSG_RESET_CACHES = 7;
 
         private static final int ARG1_NOT_GESTURE_INPUT = 0;
         private static final int ARG1_DISMISS_GESTURE_FLOATING_PREVIEW_TEXT = 1;
@@ -297,6 +298,10 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
             case MSG_ON_END_BATCH_INPUT:
                 latinIme.onEndBatchInputAsyncInternal((SuggestedWords) msg.obj);
                 break;
+            case MSG_RESET_CACHES:
+                latinIme.retryResetCaches(msg.arg1 == 1 /* tryResumeSuggestions */,
+                        msg.arg2 /* remainingTries */);
+                break;
             }
         }
 
@@ -313,6 +318,12 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
             sendMessageDelayed(obtainMessage(MSG_RESUME_SUGGESTIONS), mDelayUpdateSuggestions);
         }
 
+        public void postResetCaches(final boolean tryResumeSuggestions, final int remainingTries) {
+            removeMessages(MSG_RESET_CACHES);
+            sendMessage(obtainMessage(MSG_RESET_CACHES, tryResumeSuggestions ? 1 : 0,
+                    remainingTries, null));
+        }
+
         public void cancelUpdateSuggestionStrip() {
             removeMessages(MSG_UPDATE_SUGGESTION_STRIP);
         }
@@ -852,7 +863,6 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
         // span, so we should reset our state unconditionally, even if restarting is true.
         mEnteredText = null;
         resetComposingState(true /* alsoResetLastComposedWord */);
-        if (isDifferentTextField) mHandler.postResumeSuggestions();
         mDeleteCount = 0;
         mSpaceState = SPACE_STATE_NONE;
         mRecapitalizeStatus.deactivate();
@@ -871,8 +881,16 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
         }
         mSuggestedWords = SuggestedWords.EMPTY;
 
-        mConnection.resetCachesUponCursorMove(editorInfo.initialSelStart,
+        // Sometimes, while rotating, for some reason the framework tells the app we are not
-                false /* shouldFinishComposition */);
+        // connected to it and that means we can't refresh the cache. In this case, schedule a
+        // refresh later.
+        if (!mConnection.resetCachesUponCursorMoveAndReturnSuccess(editorInfo.initialSelStart,
+                false /* shouldFinishComposition */)) {
+            // We try resetting the caches up to 5 times before giving up.
+            mHandler.postResetCaches(isDifferentTextField, 5 /* remainingTries */);
+        } else {
+            if (isDifferentTextField) mHandler.postResumeSuggestions();
+        }
 
         if (isDifferentTextField) {
             mainKeyboardView.closing();
@@ -899,6 +917,9 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
 
         mLastSelectionStart = editorInfo.initialSelStart;
         mLastSelectionEnd = editorInfo.initialSelEnd;
+        // In some cases (namely, after rotation of the device) editorInfo.initialSelStart is lying
+        // so we try using some heuristics to find out about these and fix them.
+        tryFixLyingCursorPosition();
 
         mHandler.cancelUpdateSuggestionStrip();
         mHandler.cancelDoubleSpacePeriodTimer();
@@ -918,6 +939,35 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
         if (TRACE) Debug.startMethodTracing("/data/trace/latinime");
     }
 
+    /**
+     * Try to get the text from the editor to expose lies the framework may have been
+     * telling us. Concretely, when the device rotates, the frameworks tells us about where the
+     * cursor used to be initially in the editor at the time it first received the focus; this
+     * may be completely different from the place it is upon rotation. Since we don't have any
+     * means to get the real value, try at least to ask the text view for some characters and
+     * detect the most damaging cases: when the cursor position is declared to be much smaller
+     * than it really is.
+     */
+    private void tryFixLyingCursorPosition() {
+        final CharSequence textBeforeCursor =
+                mConnection.getTextBeforeCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE, 0);
+        if (null == textBeforeCursor) {
+            mLastSelectionStart = mLastSelectionEnd = NOT_A_CURSOR_POSITION;
+        } else {
+            final int textLength = textBeforeCursor.length();
+            if (textLength > mLastSelectionStart
+                    || (textLength < Constants.EDITOR_CONTENTS_CACHE_SIZE
+                            && mLastSelectionStart < Constants.EDITOR_CONTENTS_CACHE_SIZE)) {
+                mLastSelectionStart = textLength;
+                // We can't figure out the value of mLastSelectionEnd :(
+                // But at least if it's smaller than mLastSelectionStart something is wrong
+                if (mLastSelectionStart > mLastSelectionEnd) {
+                    mLastSelectionEnd = mLastSelectionStart;
+                }
+            }
+        }
+    }
+
     // Initialization of personalization debug settings. This must be called inside
     // onStartInputView.
     private void initPersonalizationDebugSettings(SettingsValues currentSettingsValues) {
@@ -1072,7 +1122,7 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
                 // argument as true. But in all cases where we don't reset the entire input state,
                 // we still want to tell the rich input connection about the new cursor position so
                 // that it can update its caches.
-                mConnection.resetCachesUponCursorMove(newSelStart,
+                mConnection.resetCachesUponCursorMoveAndReturnSuccess(newSelStart,
                         false /* shouldFinishComposition */);
             }
 
@@ -1308,7 +1358,8 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
         } else {
             setSuggestedWords(settingsValues.mSuggestPuncList, false);
         }
-        mConnection.resetCachesUponCursorMove(newCursorPosition, shouldFinishComposition);
+        mConnection.resetCachesUponCursorMoveAndReturnSuccess(newCursorPosition,
+                shouldFinishComposition);
     }
 
     private void resetComposingState(final boolean alsoResetLastComposedWord) {
@@ -2853,6 +2904,27 @@ public class LatinIME extends InputMethodService implements KeyboardActionListen
         mHandler.postUpdateSuggestionStrip();
     }
 
+    /**
+     * Retry resetting caches in the rich input connection.
+     *
+     * When the editor can't be accessed we can't reset the caches, so we schedule a retry.
+     * This method handles the retry, and re-schedules a new retry if we still can't access.
+     * We only retry up to 5 times before giving up.
+     *
+     * @param tryResumeSuggestions Whether we should resume suggestions or not.
+     * @param remainingTries How many times we may try again before giving up.
+     */
+    private void retryResetCaches(final boolean tryResumeSuggestions, final int remainingTries) {
+        if (!mConnection.resetCachesUponCursorMoveAndReturnSuccess(mLastSelectionStart, false)) {
+            if (0 < remainingTries) {
+                mHandler.postResetCaches(tryResumeSuggestions, remainingTries - 1);
+            }
+            return;
+        }
+        tryFixLyingCursorPosition();
+        if (tryResumeSuggestions) mHandler.postResumeSuggestions();
+    }
+
     private void revertCommit() {
         final String previousWord = mLastComposedWord.mPrevWord;
         final String originallyTypedWord = mLastComposedWord.mTypedWord;

java/src/com/android/inputmethod/latin/RichInputConnection.java

@@ -73,9 +73,6 @@ public final class RichInputConnection {
      * This contains the currently composing text, as LatinIME thinks the TextView is seeing it.
      */
     private final StringBuilder mComposingText = new StringBuilder();
-    // A hint on how many characters to cache from the TextView. A good value of this is given by
-    // how many characters we need to be able to almost always find the caps mode.
-    private static final int DEFAULT_TEXT_CACHE_SIZE = 100;
 
     private final InputMethodService mParent;
     InputConnection mIC;
@@ -93,7 +90,8 @@ public final class RichInputConnection {
         r.token = 1;
         r.flags = 0;
         final ExtractedText et = mIC.getExtractedText(r, 0);
-        final CharSequence beforeCursor = getTextBeforeCursor(DEFAULT_TEXT_CACHE_SIZE, 0);
+        final CharSequence beforeCursor = getTextBeforeCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE,
+                0);
         final StringBuilder internal = new StringBuilder().append(mCommittedTextBeforeComposingText)
                 .append(mComposingText);
         if (null == et || null == beforeCursor) return;
@@ -142,19 +140,56 @@ public final class RichInputConnection {
         if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
     }
 
-    public void resetCachesUponCursorMove(final int newCursorPosition,
+    /**
+     * Reset the cached text and retrieve it again from the editor.
+     *
+     * This should be called when the cursor moved. It's possible that we can't connect to
+     * the application when doing this; notably, this happens sometimes during rotation, probably
+     * because of a race condition in the framework. In this case, we just can't retrieve the
+     * data, so we empty the cache and note that we don't know the new cursor position, and we
+     * return false so that the caller knows about this and can retry later.
+     *
+     * @param newCursorPosition The new position of the cursor, as received from the system.
+     * @param shouldFinishComposition Whether we should finish the composition in progress.
+     * @return true if we were able to connect to the editor successfully, false otherwise. When
+     *   this method returns false, the caches could not be correctly refreshed so they were only
+     *   reset: the caller should try again later to return to normal operation.
+     */
+    public boolean resetCachesUponCursorMoveAndReturnSuccess(final int newCursorPosition,
             final boolean shouldFinishComposition) {
         mExpectedCursorPosition = newCursorPosition;
         mComposingText.setLength(0);
         mCommittedTextBeforeComposingText.setLength(0);
-        final CharSequence textBeforeCursor = getTextBeforeCursor(DEFAULT_TEXT_CACHE_SIZE, 0);
+        mIC = mParent.getCurrentInputConnection();
-        if (null != textBeforeCursor) mCommittedTextBeforeComposingText.append(textBeforeCursor);
+        // Call upon the inputconnection directly since our own method is using the cache, and
+        // we want to refresh it.
+        final CharSequence textBeforeCursor = null == mIC ? null :
+                mIC.getTextBeforeCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE, 0);
+        if (null == textBeforeCursor) {
+            // For some reason the app thinks we are not connected to it. This looks like a
+            // framework bug... Fall back to ground state and return false.
+            mExpectedCursorPosition = INVALID_CURSOR_POSITION;
+            Log.e(TAG, "Unable to connect to the editor to retrieve text... will retry later");
+            return false;
+        }
+        mCommittedTextBeforeComposingText.append(textBeforeCursor);
+        final int lengthOfTextBeforeCursor = textBeforeCursor.length();
+        if (lengthOfTextBeforeCursor > newCursorPosition
+                || (lengthOfTextBeforeCursor < Constants.EDITOR_CONTENTS_CACHE_SIZE
+                        && newCursorPosition < Constants.EDITOR_CONTENTS_CACHE_SIZE)) {
+            // newCursorPosition may be lying -- when rotating the device (probably a framework
+            // bug). If we have less chars than we asked for, then we know how many chars we have,
+            // and if we got more than newCursorPosition says, then we know it was lying. In both
+            // cases the length is more reliable
+            mExpectedCursorPosition = lengthOfTextBeforeCursor;
+        }
         if (null != mIC && shouldFinishComposition) {
             mIC.finishComposingText();
             if (ProductionFlag.USES_DEVELOPMENT_ONLY_DIAGNOSTICS) {
                 ResearchLogger.richInputConnection_finishComposingText();
             }
         }
+        return true;
     }
 
     private void checkBatchEdit() {
@@ -233,7 +268,8 @@ public final class RichInputConnection {
         // getCapsMode should be updated to be able to return a "not enough info" result so that
         // we can get more context only when needed.
         if (TextUtils.isEmpty(mCommittedTextBeforeComposingText) && 0 != mExpectedCursorPosition) {
-            final CharSequence textBeforeCursor = getTextBeforeCursor(DEFAULT_TEXT_CACHE_SIZE, 0);
+            final CharSequence textBeforeCursor = getTextBeforeCursor(
+                    Constants.EDITOR_CONTENTS_CACHE_SIZE, 0);
             if (!TextUtils.isEmpty(textBeforeCursor)) {
                 mCommittedTextBeforeComposingText.append(textBeforeCursor);
             }
@@ -364,7 +400,7 @@ public final class RichInputConnection {
         if (DEBUG_BATCH_NESTING) checkBatchEdit();
         if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
         final CharSequence textBeforeCursor =
-                getTextBeforeCursor(DEFAULT_TEXT_CACHE_SIZE + (end - start), 0);
+                getTextBeforeCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE + (end - start), 0);
         mCommittedTextBeforeComposingText.setLength(0);
         if (!TextUtils.isEmpty(textBeforeCursor)) {
             final int indexOfStartOfComposingText =
@@ -406,7 +442,8 @@ public final class RichInputConnection {
         }
         mExpectedCursorPosition = start;
         mCommittedTextBeforeComposingText.setLength(0);
-        mCommittedTextBeforeComposingText.append(getTextBeforeCursor(DEFAULT_TEXT_CACHE_SIZE, 0));
+        mCommittedTextBeforeComposingText.append(
+                getTextBeforeCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE, 0));
     }
 
     public void commitCorrection(final CorrectionInfo correctionInfo) {
@@ -525,9 +562,9 @@ public final class RichInputConnection {
         if (mIC == null || sep == null) {
             return null;
         }
-        final CharSequence before = mIC.getTextBeforeCursor(1000,
+        final CharSequence before = mIC.getTextBeforeCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE,
                 InputConnection.GET_TEXT_WITH_STYLES);
-        final CharSequence after = mIC.getTextAfterCursor(1000,
+        final CharSequence after = mIC.getTextAfterCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE,
                 InputConnection.GET_TEXT_WITH_STYLES);
         if (before == null || after == null) {
             return null;