RTEditor/src/main/java/com/onegravity/rteditor/RTManager.java
public void registerToolbar(ViewGroup toolbarContainer, RTToolbar toolbar) {
        mToolbars.put(toolbar.getId(), toolbar);
        toolbar.setToolbarListener(this);
        toolbar.setToolbarContainer(toolbarContainer);

        updateToolbarVisibility();
    }
public void registerToolbar(ViewGroup toolbarContainer, RTToolbar toolbar) {
        mToolbars.put(toolbar.getId(), toolbar);
        toolbar.setToolbarListener(this);
        toolbar.setToolbarContainer(toolbarContainer);

        updateToolbarVisibility();
    }
Register a toolbar.
<p>
Only after doing that can it be used in conjunction with a rich text editor.
Must be called from the ui thread.

@param toolbarContainer The ViewGroup containing the toolbar.
This container is used to show/hide the toolbar if needed (e.g. if the RTEditText field loses/gains focus).
We can't use the toolbar itself because there could be multiple and they could be embedded in a complex layout hierarchy.
@param toolbar          The toolbar to register.