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
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();
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;
}