Return the cursor position in screen coordinates

From its beginning, InputMethodService#onUpdateCursor has
provided the cursor position in local coordinates in the attached
view. However, the local coordinates is not useful for IMEs
to render a floating UI near the cursor because the IME is not
able to know the origin of the attached view.

With this CL, CURSOR_ANCHOR_MONITOR_MODE_CURSOR_RECT also means
that the IME will receive the cursor position in screen
coordinates. Because this is a new constant in the next release,
conditionally changing the coordinates never causes
compatibility issues as long as its behavior is well documented.

BUG: 14323360
Change-Id: I3acf2317ae1d763d11dae5ef73c2a1348b377c71

2 files changed, 32 insertions, 8 deletions

diff --git a/core/java/android/inputmethodservice/InputMethodService.java b/core/java/android/inputmethodservice/InputMethodService.java
index c51d1a78e5ad..ec581d1a71e1 100644
--- a/core/java/android/inputmethodservice/InputMethodService.java
+++ b/core/java/android/inputmethodservice/InputMethodService.java
@@ -255,7 +255,8 @@ public class InputMethodService extends AbstractInputMethodService {
     public static final int CURSOR_ANCHOR_MONITOR_MODE_NONE = 0x0;
 
     /**
-     * The IME expects that {@link #onUpdateCursor(Rect)} is called back.
+     * The IME will receive {@link #onUpdateCursor(Rect)} called back with the current
+     * cursor rectangle in screen coordinates.
      */
     public static final int CURSOR_ANCHOR_MONITOR_MODE_CURSOR_RECT = 0x1;
 
@@ -1703,9 +1704,11 @@ public class InputMethodService extends AbstractInputMethodService {
     }
 
     /**
-     * Called when the application has reported a new location of its text
-     * cursor.  This is only called if explicitly requested by the input method.
-     * The default implementation does nothing.
+     * Called when the application has reported a new location of its text cursor.  This is only
+     * called if explicitly requested by the input method.  The default implementation does nothing.
+     * @param newCursor The new cursor position, in screen coordinates if the input method calls
+     * {@link #setCursorAnchorMonitorMode} with {@link #CURSOR_ANCHOR_MONITOR_MODE_CURSOR_RECT}.
+     * Otherwise, this is in local coordinates.
      */
     public void onUpdateCursor(Rect newCursor) {
         // Intentionally empty
diff --git a/core/java/android/view/inputmethod/InputMethodManager.java b/core/java/android/view/inputmethod/InputMethodManager.java
index e3bd9fd261be..02278733d270 100644
--- a/core/java/android/view/inputmethod/InputMethodManager.java
+++ b/core/java/android/view/inputmethod/InputMethodManager.java
@@ -317,6 +317,10 @@ public final class InputMethodManager {
     int mCursorSelEnd;
     int mCursorCandStart;
     int mCursorCandEnd;
+    /**
+     * The buffer to retrieve the view location in screen coordinates in {@link #updateCursor}.
+     */
+    private final int[] mViewTopLeft = new int[2];
 
     // -----------------------------------------------------------
     
@@ -1487,12 +1491,26 @@ public final class InputMethodManager {
             return false;
         }
         synchronized (mH) {
-            return mCursorAnchorMonitorMode ==
-                    InputMethodService.CURSOR_ANCHOR_MONITOR_MODE_CURSOR_RECT;
+            return (mCursorAnchorMonitorMode &
+                    InputMethodService.CURSOR_ANCHOR_MONITOR_MODE_CURSOR_RECT) != 0;
         }
     }
 
     /**
+     * Returns true if the current input method wants to receive the cursor rectangle in
+     * screen coordinates rather than local coordinates in the attached view.
+     *
+     * @hide
+     */
+    public boolean usesScreenCoordinatesForCursorLocked() {
+        // {@link InputMethodService#CURSOR_ANCHOR_MONITOR_MODE_CURSOR_RECT} also means
+        // that {@link InputMethodService#onUpdateCursor} should provide the cursor rectangle
+        // in screen coordinates rather than local coordinates.
+        return (mCursorAnchorMonitorMode &
+                InputMethodService.CURSOR_ANCHOR_MONITOR_MODE_CURSOR_RECT) != 0;
+    }
+
+    /**
      * Set cursor/anchor monitor mode via {@link com.android.server.InputMethodManagerService}.
      * This is an internal method for {@link android.inputmethodservice.InputMethodService} and
      * should never be used from IMEs and applications.
@@ -1518,15 +1536,18 @@ public final class InputMethodManager {
                     || mCurrentTextBoxAttribute == null || mCurMethod == null) {
                 return;
             }
-            
             mTmpCursorRect.set(left, top, right, bottom);
             if (!mCursorRect.equals(mTmpCursorRect)) {
                 if (DEBUG) Log.d(TAG, "updateCursor");
 
                 try {
                     if (DEBUG) Log.v(TAG, "CURSOR CHANGE: " + mCurMethod);
-                    mCurMethod.updateCursor(mTmpCursorRect);
                     mCursorRect.set(mTmpCursorRect);
+                    if (usesScreenCoordinatesForCursorLocked()) {
+                        view.getLocationOnScreen(mViewTopLeft);
+                        mTmpCursorRect.offset(mViewTopLeft[0], mViewTopLeft[1]);
+                    }
+                    mCurMethod.updateCursor(mTmpCursorRect);
                 } catch (RemoteException e) {
                     Log.w(TAG, "IME died: " + mCurId, e);
                 }