Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6fcbb562 authored by Yohei Yukawa's avatar Yohei Yukawa
Browse files

Handle BadTokenException exception more reliably. 

This is a follow up for I2c21573cf972145ab08e66604cdb9344139a3f31, which
added BadTokenException handler so that we can deal with unavoidable
runtime exceptions. However, it turns out that CL does not work well
in a certain case.

One problem in I2c21573cf972145ab08e66604cdb9344139a3f31 that it added
the exception handler in the call site of
InputMethodService#showWindow(boolean) rather than callee side as
follows.

    try {
        showWindow(true);
    } catch (BadTokenException e) {
        if (DEBUG) Log.v(TAG, "BadTokenException: IME is done.");
        mWindowVisible = false;
    }

However, the above code fails to update #mWindowVisible if an IME
overrides InputMethodService#showWindow(boolean) but catch-and-ignore
BadTokenException as follows.

    @Override
    public void showWindow(boolean showInput) {
        try {
            super.showWindow(showInput);
            // Do something if super.showWindow() succeeds.
        } catch (BadTokenException ex) {
            // Do something if super.showWindow() fails.
        }
    }

With this CL, InputMethodService#mWindowVisible is always updated in
the callee side whenever it should be.

Note that this CL does not change anything about which method can
throw BadTokenException and which method catch-and-ignores it so as
not to break existing IMEs unexpectedly.

Bug: 23798142
Change-Id: Id1e5f236f48c8ef01b7f157ba3f6e7ab2c26b135
parent 0f07424d

core/java/android/inputmethodservice/InputMethodService.java

+18 −3
Original line number Diff line number Diff line
@@ -436,9 +436,12 @@ public class InputMethodService extends AbstractInputMethodService { 
                try {

                    showWindow(true);

                } catch (BadTokenException e) {

                    if (DEBUG) Log.v(TAG, "BadTokenException: IME is done.");

                    mWindowVisible = false;

                    mWindowAdded = false;

                    // We have ignored BadTokenException here since Jelly Bean MR-2 (API Level 18).

                    // We could ignore BadTokenException in InputMethodService#showWindow() instead,

                    // but it may break assumptions for those who override #showWindow() that we can

                    // detect errors in #showWindow() by checking BadTokenException.

                    // TODO: Investigate its feasibility.  Update JavaDoc of #showWindow() of

                    // whether it's OK to override #showWindow() or not.

                }

            }

            clearInsetOfPreviousIme();
@@ -1445,7 +1448,19 @@ public class InputMethodService extends AbstractInputMethodService { 
            mWindowWasVisible = mWindowVisible;

            mInShowWindow = true;

            showWindowInner(showInput);

        } catch (BadTokenException e) {

            // BadTokenException is a normal consequence in certain situations, e.g., swapping IMEs

            // while there is a DO_SHOW_SOFT_INPUT message in the IIMethodWrapper queue.

            if (DEBUG) Log.v(TAG, "BadTokenException: IME is done.");

            mWindowVisible = false;

            mWindowAdded = false;

            // Rethrow the exception to preserve the existing behavior.  Some IMEs may have directly

            // called this method and relied on this exception for some clean-up tasks.

            // TODO: Give developers a clear guideline of whether it's OK to call this method or

            // InputMethodManager#showSoftInputFromInputMethod() should always be used instead.

            throw e;

        } finally {

            // TODO: Is it OK to set true when we get BadTokenException?

            mWindowWasVisible = true;

            mInShowWindow = false;

        }