Application crashes when I execute Keyboard.SetShifted

Question

I am trying to make a custom soft keyboard, my problem comes when I try to use the method setshifted of my keyboard, application get crashed.

Here is my output error:

02-19 19:58:45.649 2222-2222/? E/InputEventReceiver: Exception dispatching input event. 02-19 19:58:45.649 2222-2222/? E/MessageQueue-JNI: Exception in MessageQueue callback: handleReceiveCallback 02-19 19:58:45.649 2222-2222/? E/MessageQueue-JNI: java.lang.StringIndexOutOfBoundsException: length=0; index=0 at java.lang.String.indexAndLength(String.java:584) at java.lang.String.charAt(String.java:578) at android.inputmethodservice.KeyboardView.adjustCase(KeyboardView.java:577) at android.inputmethodservice.KeyboardView.onBufferDraw(KeyboardView.java:687) at android.inputmethodservice.KeyboardView.invalidateKey(KeyboardView.java:1054) at android.inputmethodservice.KeyboardView.onModifiedTouchEvent(KeyboardView.java:1348) at android.inputmethodservice.KeyboardView.onTouchEvent(KeyboardView.java:1209) at android.view.View.dispatchTouchEvent(View.java:7706) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2068) at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1515) at android.app.Activity.dispatchTouchEvent(Activity.java:2458) at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:71) at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:71) at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2016) at android.view.View.dispatchPointerEvent(View.java:7886) at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:3978) at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:3857) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3423) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3473) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3442) at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3549) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3450) at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:3606) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3423) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3473) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3442) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3450) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3423) at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:5626) at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:5606) at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:5577) at android.view.ViewRootImpl$WindowInputEventReceiver.onInputEvent(ViewRootImpl.java:5706) at android.view.InputEventReceiver.dis 02-19 19:58:45.649 2222-2222/? D/AndroidRuntime: Shutting down VM 02-19 19:58:45.649 2222-2222/? W/dalvikvm: threadid=1: thread exiting with uncaught exception (group=0x94c9bb20) 02-19 19:58:45.649 2222-2222/? E/AndroidRuntime: FATAL EXCEPTION: main Process: app.parkinghelper.com.parkinghelper11, PID: 2222 java.lang.StringIndexOutOfBoundsException: length=0; index=0 at java.lang.String.indexAndLength(String.java:584) at java.lang.String.charAt(String.java:578) at android.inputmethodservice.KeyboardView.adjustCase(KeyboardView.java:577) at android.inputmethodservice.KeyboardView.onBufferDraw(KeyboardView.java:687) at android.inputmethodservice.KeyboardView.invalidateKey(KeyboardView.java:1054) at android.inputmethodservice.KeyboardView.onModifiedTouchEvent(KeyboardView.java:1348) at android.inputmethodservice.KeyboardView.onTouchEvent(KeyboardView.java:1209) at android.view.View.dispatchTouchEvent(View.java:7706) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2216) at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1959) at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2068) at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1515) at android.app.Activity.dispatchTouchEvent(Activity.java:2458) at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:71) at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:71) at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2016) at android.view.View.dispatchPointerEvent(View.java:7886) at android.view.ViewRootImpl$ViewPostImeInputStage.processPointerEvent(ViewRootImpl.java:3978) at android.view.ViewRootImpl$ViewPostImeInputStage.onProcess(ViewRootImpl.java:3857) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3423) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3473) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3442) at android.view.ViewRootImpl$AsyncInputStage.forward(ViewRootImpl.java:3549) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3450) at android.view.ViewRootImpl$AsyncInputStage.apply(ViewRootImpl.java:3606) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3423) at android.view.ViewRootImpl$InputStage.onDeliverToNext(ViewRootImpl.java:3473) at android.view.ViewRootImpl$InputStage.forward(ViewRootImpl.java:3442) at android.view.ViewRootImpl$InputStage.apply(ViewRootImpl.java:3450) at android.view.ViewRootImpl$InputStage.deliver(ViewRootImpl.java:3423) at android.view.ViewRootImpl.deliverInputEvent(ViewRootImpl.java:5626) at android.view.ViewRootImpl.doProcessInputEvents(ViewRootImpl.java:5606) at android.view.ViewRootImpl.enqueueInputEvent(ViewRootImpl.java:5577) at android.view.ViewRootImpl$WindowInputEventReceive

Constructor of the keyboard class

ph_ckb_2(Activity host, View kbview, int viewid, int Layoutid1) {

        mHostActivity = host;
        m_RootView = kbview;
        i_kbid1 = Layoutid1;

        kb_1 = new Keyboard(mHostActivity, i_kbid1);

        mKeyboardView = (KeyboardView)m_RootView.findViewById(viewid);
        mKeyboardView.setKeyboard(kb_1);
        mKeyboardView.setPreviewEnabled(false);

        mKeyboardView.setOnKeyboardActionListener(mOnKeyboardActionListener);
        // Hide the standard keyboard initially
        mHostActivity.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
        hideCustomKeyboard();

    }

Input function

    @Override
    public void onKey(int primaryCode, int[] keyCodes) {              
        View focusCurrent = mHostActivity.getWindow().getCurrentFocus();

        assert focusCurrent != null;

        Class<? extends View> GetTextClass = focusCurrent.getClass();

        if (GetTextClass == AppCompatEditText.class || GetTextClass == AppCompatAutoCompleteTextView.class) {
            EditText edittext = (EditText) focusCurrent;
            Editable editable = edittext.getText();
            int start = edittext.getSelectionStart();
            if (primaryCode == CodeShift) {
                bShifted = !bShifted;
                mKeyboardView.setShifted(bShifted);
                mKeyboardView.invalidateAllKeys();                   
            } else { 
                editable.insert(start, Character.toString((char) primaryCode));
            }
        }
    }

Original code here Crea un teclado personalizado en Android and here Android development: Custom keyboard

Answer 1

Check that you do not have a Key with an empty Label. If it is empty, then this bug will occur.

For example this will cause a bug:

<Row android:horizontalGap="0%p" android:keyHeight="0%p">
    <Key android:codes="32" android:keyLabel="" android:keyWidth="100%p" />
</Row>

Answer 2

There is an obvious bug in the adjustCase method that leads to StringIndexOutOfBoundsException exception for empty strings.

private CharSequence adjustCase(CharSequence label) {
    if (mKeyboard.isShifted() && label != null && label.length() < 3
            && Character.isLowerCase(label.charAt(0))) {
        label = label.toString().toUpperCase();
    }
    return label;
}