Keep IMM#mCurRootView synchronized with the actual window focus.

Currently IMM#mCurRootView is always cleared every time when
IMM#finishInputLocked() is called.  We have been doing this since
Iad09cf5dbb7f6f156fd39ed243431432e00f8945 so as not to hold the
strong reference to a DecorView so long time (Bug 6413553).

Strictly speaking, the attached window may continue holding
input focus even after IMM#finishInputLocked() is called.
In this state IMM#focusIn() might have unexpectedly rejected
focus-in event but presumably this might not be obvious, or might
not occur at all because in some situations IMM#finishInputLocked()
has never been called even when the attached view loses input
focus.

In order to fix Issue 20820914, however, we need to call
IMM#finishInputLocked() exactly when the attached view loses
input focus.  To make it easier to diagnose any unexpected
regressions, this CL only changes the handling of
IMM#mCurRootView, while the next CL Id6afc8fc64512225578c62557b96
plumbs IMM#focusOut() to IMM#finishInputLocked().

Manually tested following scenarios.
- Repro steps in Bug 6413553.  Made sure that IMM#mCurRootView
  is cleared after switching back from the current application to
  the previous application with back key.
- Test application that calls WebView#showFindDialog(). Made sure
  that LatinIME works fine when switching text fields.  This is
  non-trivial because android.webkit.FindActionModeCallback is
  changed in this CL.
- Repro steps in Bug 21144633.  Made sure that we can enter
  recipient's name in the messaging app.

Bug: 20820914
Change-Id: I219394178e4172bc47864297f1418e677dba25e5

1 files changed, 6 insertions, 7 deletions

diff --git a/core/java/android/view/ViewRootImpl.java b/core/java/android/view/ViewRootImpl.java
index 4f2a3fa..4743494 100644
--- a/core/java/android/view/ViewRootImpl.java
+++ b/core/java/android/view/ViewRootImpl.java
@@ -2015,8 +2015,8 @@ public final class ViewRootImpl implements ViewParent,
                 mLastWasImTarget = imTarget;
                 InputMethodManager imm = InputMethodManager.peekInstance();
                 if (imm != null && imTarget) {
-                    imm.startGettingWindowFocus(mView);
-                    imm.onWindowFocus(mView, mView.findFocus(),
+                    imm.onPreWindowFocus(mView, true /* hasWindowFocus */);
+                    imm.onPostWindowFocus(mView, mView.findFocus(),
                             mWindowAttributes.softInputMode,
                             !mHasHadWindowFocus, mWindowAttributes.flags);
                 }
@@ -3321,11 +3321,10 @@ public final class ViewRootImpl implements ViewParent,
                             .mayUseInputMethod(mWindowAttributes.flags);
 
                     InputMethodManager imm = InputMethodManager.peekInstance();
+                    if (imm != null && mLastWasImTarget && !isInLocalFocusMode()) {
+                        imm.onPreWindowFocus(mView, hasWindowFocus);
+                    }
                     if (mView != null) {
-                        if (hasWindowFocus && imm != null && mLastWasImTarget &&
-                                !isInLocalFocusMode()) {
-                            imm.startGettingWindowFocus(mView);
-                        }
                         mAttachInfo.mKeyDispatchState.reset();
                         mView.dispatchWindowFocusChanged(hasWindowFocus);
                         mAttachInfo.mTreeObserver.dispatchOnWindowFocusChange(hasWindowFocus);
@@ -3335,7 +3334,7 @@ public final class ViewRootImpl implements ViewParent,
                     // so all of the view state is set up correctly.
                     if (hasWindowFocus) {
                         if (imm != null && mLastWasImTarget && !isInLocalFocusMode()) {
-                            imm.onWindowFocus(mView, mView.findFocus(),
+                            imm.onPostWindowFocus(mView, mView.findFocus(),
                                     mWindowAttributes.softInputMode,
                                     !mHasHadWindowFocus, mWindowAttributes.flags);
                         }