Ticket #2053: CapsLockFilter.2.cpp

/*
 * Copyright 2012, Haiku, Inc.  All Rightrs Reserved
 * Distributed under the terms of the MIT License.
 *
 * Authors:
 *      Philippe Saint-Pierre <stpere@gmail.com>
 *      Pete Goodeve <pete.goodeve
 */


#include <OS.h>
#include <InputServerFilter.h>
#include <InterfaceDefs.h>

#include <new>


class CapsLockFilter : public BInputServerFilter {
    public:
        CapsLockFilter();

        virtual filter_result Filter(BMessage* message, BList*);

    private:
        bool fCapsLocked;
};


CapsLockFilter::CapsLockFilter(): fCapsLocked(false)
{
}


filter_result
CapsLockFilter::Filter(BMessage* message, BList*)
{
    if (message->what == B_MODIFIERS_CHANGED) {
        int32 modifiers;
        message->FindInt32("modifiers", &modifiers);
        if (modifiers & B_CAPS_LOCK) {
            if (!fCapsLocked && !(modifiers & B_CONTROL_KEY)) {
                modifiers &= B_SCROLL_LOCK | B_NUM_LOCK;
                    // clear CAPS -- ignore SHIFT etc.
                set_keyboard_locks(modifiers);
                return B_SKIP_MESSAGE;
            } else
                fCapsLocked = true;
        } else
            fCapsLocked = false;
    }

    return B_DISPATCH_MESSAGE;
}


extern "C" _EXPORT BInputServerFilter* instantiate_input_filter();

BInputServerFilter*
instantiate_input_filter()
{
    return new (std::nothrow) CapsLockFilter();
}