void switchWaitingOrHoldingAndActive() throws CallStateException {
if (DBG) log("switchWaitingOrHoldingAndActive");
if (mRingingCall.getState() == ImsPhoneCall.State.INCOMING) {
throw new CallStateException("cannot be in the incoming state");
}
if (mForegroundCall.getState() == ImsPhoneCall.State.ACTIVE) {
ImsCall imsCall = mForegroundCall.getImsCall();
if (imsCall == null) {
throw new CallStateException("no ims call");
}
// Swap the ImsCalls pointed to by the foreground and background ImsPhoneCalls.
// If hold or resume later fails, we will swap them back.
mSwitchingFgAndBgCalls = true;
mCallExpectedToResume = mBackgroundCall.getImsCall();
mForegroundCall.switchWith(mBackgroundCall);
// Hold the foreground call; once the foreground call is held, the background call will
// be resumed.
try {
imsCall.hold();
} catch (ImsException e) {
mForegroundCall.switchWith(mBackgroundCall);
throw new CallStateException(e.getMessage());
}
} else if (mBackgroundCall.getState() == ImsPhoneCall.State.HOLDING) {
resumeWaitingOrHolding();
}
}
