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Virtual keyboard/mouse infrastructure
The virtual keyboard/mouse infrastructure (or VKM), is an API used by an
application to inject keyboard and mouse events into the OS stack. The advantage
of using a separate API for this is so that this can be handled in a
cross-platform manner without having to sprinkle #ifdef's throughout the
program.
Base API
The API is based around a context, which is an opaque pointer returned by
vkm_init. All subsequent VKM calls will take in this pointer as the first
argument, and return a signed 32-bit status code. Once done, vkm_exit will
clean up any data structures and close any file descriptors that were opened as
part of the VKM calls.
VKM can also be configured through the vkm_config API call.
Device handling
vkm_new_device is the API to use when creating a new VKM device. While VKM
will support both keyboard and mouse events from a single device, there may be
cases where the application needs to separate out keyboard and mouse events into
different devices. The flags will enable keyboard and/or mouse support.
Note that the supported event codes (on Linux) are fixed, and cannot be updated. The keyboard will emulate a standard US keyboard, while the mouse will emulate a standard 3 button mouse with a scroll wheel.
Mouse handling
The mouse is handled as a single API call that passes in dx and dy to move the
mouse in the relative X and Y axes. VKM will take care of internally translating
the calls to the appropriate framework. This is handled in vkm_mouse_move
The scroll wheel is handled through vkm_mouse_scroll. By default, the mouse
motion uses standard scrolling, but high resolution scrolling may be enabled.
The buttons are handled by vkm_mouse_click. The API will send the state,
depending on the input (pressed or not)
Keyboard handling
The keyboard is handled through a single call vkm_keyboard_send. This sends a
single key event, with modifiers enabled (Ctrl, Shift, Alt, GUI).