Support InputMethodManager#updateCursorAnchorInfo for Android 5.0

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

Index: content/public/android/java/src/org/chromium/content/browser/input/ImeAdapter.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/input/ImeAdapter.java b/content/public/android/java/src/org/chromium/content/browser/input/ImeAdapter.java
index e075d8e4d400dbef2f502c3f262b3455eed249a6..4d8c29efedf345c6bcb566e4e03bac29a54ba49a 100644
--- a/content/public/android/java/src/org/chromium/content/browser/input/ImeAdapter.java
+++ b/content/public/android/java/src/org/chromium/content/browser/input/ImeAdapter.java
@@ -4,6 +4,8 @@
 
 package org.chromium.content.browser.input;
 
+import android.graphics.Matrix;
+import android.os.Build;
 import android.os.Handler;
 import android.os.ResultReceiver;
 import android.os.SystemClock;
@@ -15,7 +17,10 @@ import android.text.style.UnderlineSpan;
 import android.view.KeyCharacterMap;
 import android.view.KeyEvent;
 import android.view.View;
+import android.view.inputmethod.CursorAnchorInfo;
 import android.view.inputmethod.EditorInfo;
+import android.view.inputmethod.InputConnection;
+import android.view.inputmethod.InputMethodManager;
 
 import org.chromium.base.CalledByNative;
 import org.chromium.base.JNINamespace;
@@ -143,6 +148,53 @@ public class ImeAdapter {
     private int mTextInputFlags;
     private String mLastComposeText;
 
+    private static class CursorAnchorInfoSource {
+        private String mText;
+        private int mSelectionStart;
+        private int mSelectionEnd;
+        private int mCompositionStart;
+        private int mCompositionEnd;
+        private float[] mLastCharacterBounds;
+    }
+    private CursorAnchorInfoSource mCursorAnchorInfoSource = new CursorAnchorInfoSource();
+
+    private static class CursorAnchorInfoBuilderWrapper {
+
+        public static boolean isSupported() {
+            return false;
+        }
+
+        public static CursorAnchorInfoBuilderWrapper create() {
+            return new CursorAnchorInfoBuilderWrapper();
+        }
+
+        protected CursorAnchorInfoBuilderWrapper() {
+        }
+
+        public void update(CursorAnchorInfoSource source, Matrix matrix, boolean hasInertionMarker,
+                float insertionMarkerX, float insertionMarkerTop, float insertionMarkerBottom) {
+            // This is a stub for platforms that do not support CursorAnchorInfo.
+        }
+
+        public boolean hasData() {
+            // This is a stub for platforms that do not support CursorAnchorInfo.
+            return false;
+        }
+
+        public void reset() {
+            // This is a stub for platforms that do not support CursorAnchorInfo.
+        }
+
+        public void send(InputMethodManagerWrapper inputMethodManagerWrapper, View view) {
+            // This is a stub for platforms that do not support CursorAnchorInfo.
+        }
+    }
+
+    private CursorAnchorInfoBuilderWrapper mCursorAnchorInfoBuilder =
+            CursorAnchorInfoBuilderWrapper.create();
+    private boolean mCursorAnchorInfoMonitorEnabled = false;
+    private boolean mOneshotUpdateCursorAnchorInfoEnabled = false;
+
     @VisibleForTesting
     int mLastSyntheticKeyCode;
 
@@ -621,6 +673,82 @@ public class ImeAdapter {
         return true;
     }
 
+    /**
+     * @return Whether the {@link CursorAnchorInfo} is available or not on this device.
+     */
+    public boolean isCursorAnchorInfoSupported() {
+        return CursorAnchorInfoBuilderWrapper.isSupported();
+    }
+
+    /**
+     * Start or stop calling
+     * {@link InputMethodManager#updateCursorAnchorInfo(View, CursorAnchorInfo)}.
+     * @param enabled {@code true} if {@link InputConnection#requestCursorUpdates(int)} is called
+     * with {@link InputConnection#CURSOR_UPDATE_MONITOR} bit.
+     */
+    public void setCursorAnchorInfoMonitorEnabled(boolean enabled) {
+        mCursorAnchorInfoMonitorEnabled = enabled;
+    }
+
+    /**
+     * Make sure {@link InputMethodManager#updateCursorAnchorInfo(View, CursorAnchorInfo)} is called
+     * at least once immediately when the latest position becomes available.
+     * @param view The view to be passed to
+     * {@link InputMethodManager#updateCursorAnchorInfo(View, CursorAnchorInfo)} if the latest
+     * position is already available. Otherwise ignored.
+     */
+    public void scheduleOneshotUpdateCursorAnchorInfo(View view) {
+        if (!mCursorAnchorInfoBuilder.hasData()) {
+            // If there is no data, send the data later when it becomes available.
+            mOneshotUpdateCursorAnchorInfoEnabled = true;
+            return;
+        }
+        mCursorAnchorInfoBuilder.send(mInputMethodManagerWrapper, view);
+        mOneshotUpdateCursorAnchorInfoEnabled = false;
+    }
+
+    /**
+     * Update the parameters that are to be passed to the IME through
+     * {@link InputMethodManager#updateCursorAnchorInfo(View, CursorAnchorInfo)}.
+     * @param text The text in the focused text field.
+     * @param selectionStart Index where the text selection starts. {@code -1} if there is no
+     * selection.
+     * @param selectionEnd Index where the text selection ends. {@code -1} if there is no
+     * selection.
+     * @param compositionStart Index where the text composition starts. {@code -1} if there is no
+     * selection.
+     * @param compositionEnd Index where the text composition ends. {@code -1} if there is no
+     * selection.
+     */
+    public void updateCursorAnchorInfoSource(String text, int selectionStart, int selectionEnd,
+            int compositionStart, int compositionEnd) {
+        mCursorAnchorInfoSource.mText = text;
+        mCursorAnchorInfoSource.mSelectionStart = selectionStart;
+        mCursorAnchorInfoSource.mSelectionEnd = selectionEnd;
+        mCursorAnchorInfoSource.mCompositionStart = compositionStart;
+        mCursorAnchorInfoSource.mCompositionEnd = compositionEnd;
+    }
+
+    /**
+     * Call {@link InputMethodManager#updateCursorAnchorInfo(View, CursorAnchorInfo)} if it is
+     * available and the active IME is actually requested it.
+     * @param view The view to be passed to
+     * {@link InputMethodManager#updateCursorAnchorInfo(View, CursorAnchorInfo)}
+     * @param matrix The matrix from CSS coordinates to the absolute display coordinates.
+     * @param hasInsertionMaerker Whether the insertion marker exists or not.
+     * @param insertionMarkerX The X position of the insertion marker, in CSS coordinates.
+     * @param insertionMarkerTop The top position of the insertion marker, in CSS coordinates.
+     * @param insertionMarkerBottom The bottom position of the insertion marker, in CSS coordinates.
+     */
+    public void updateCursorAnchorInfo(View view, Matrix matrix, boolean hasInsertionMaerker,
+            float insertionMarkerX, float insertionMarkerTop, float insertionMarkerBottom) {
+        mCursorAnchorInfoBuilder.update(mCursorAnchorInfoSource, matrix, hasInsertionMaerker,
+                insertionMarkerX, insertionMarkerTop, insertionMarkerBottom);
+        if (!mCursorAnchorInfoMonitorEnabled && !mOneshotUpdateCursorAnchorInfoEnabled) return;
+        mCursorAnchorInfoBuilder.send(mInputMethodManagerWrapper, view);
+        mOneshotUpdateCursorAnchorInfoEnabled = false;
+    }
+
     // Calls from C++ to Java
 
     @CalledByNative
@@ -699,7 +827,7 @@ public class ImeAdapter {
 
     @CalledByNative
     private void setCharacterBounds(float[] characterBounds) {
-        // TODO(yukawa): Implement this.
+        mCursorAnchorInfoSource.mLastCharacterBounds = characterBounds;
     }
 
     @CalledByNative
@@ -710,6 +838,7 @@ public class ImeAdapter {
         }
         mNativeImeAdapterAndroid = 0;
         mTextInputType = 0;
+        mCursorAnchorInfoBuilder.reset();
     }
 
     private native boolean nativeSendSyntheticKeyEvent(long nativeImeAdapterAndroid,