Introduce ThreadedInputConnection behind a switch

content/public/android/java/src/org/chromium/content/browser/input/TextInputState.java

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.content.browser.input;
+
+import android.text.TextUtils;
+
+import org.chromium.base.Log;
+
+/**
+ * A class to track and interact with the latest text input state which
+ * consists of text, selection range, and composition range.
+ */
+public class TextInputState {
+    private final CharSequence mText;
+    private final Range mSelection;
+    private final Range mComposition;
+
+    public TextInputState(CharSequence text, Range selection, Range composition) {
+        if (text == null) text = "";
+        if (selection == null) selection = getDefaultSelection();
+        if (composition == null) composition = getDefaultComposition();
+        Log.d("cr.Ime", "onUpdate");
+
+        selection.forceWithin(Range.fromText(text));
+        composition.forceWithin(Range.fromText(text));
+        mText = text;
+        mSelection = selection;
+        mComposition = composition;
+    }
+
+    public CharSequence text() {
+        return mText;
+    }
+
+    public Range selection() {
+        return mSelection;
+    }
+
+    public Range composition() {
+        return mComposition;
+    }
+
+    public CharSequence getSelectedText() {
+        return TextUtils.substring(mText, mSelection.start(), mSelection.end());
+    }
+
+    public CharSequence getTextAfterSelection(int maxChars) {
+        return TextUtils.substring(
+                mText, mSelection.end(), Math.min(mText.length(), mSelection.end() + maxChars));
+    }
+
+    public CharSequence getTextBeforeSelection(int maxChars) {
+        return TextUtils.substring(
+                mText, Math.max(0, mSelection.start() - maxChars), mSelection.start());
+    }
+
+    private static Range getDefaultSelection() {
+        return new Range(0, 0);
+    }
+
+    private static Range getDefaultComposition() {
+        return new Range(-1, -1);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (!(o instanceof Range)) return false;
+        if (o == this) return true;
+        TextInputState t = (TextInputState) o;
+        return TextUtils.equals(mText, t.mText) && mSelection == t.mSelection
+                && mComposition == t.mComposition;
+    }
+
+    @Override
+    public int hashCode() {
+        return mText.hashCode() * 7 + mSelection.hashCode() * 11 + mComposition.hashCode() * 13;
+    }
+
+    public boolean isDummy() {
+        return false;
+    }
+
+    static class Dummy extends TextInputState {
+        public Dummy() {
+            super("", null, null);
+        }
+
+        @Override
+        public boolean isDummy() {
+            return true;
+        }
+    }
+}