From this line https://gitorious.org/community-ssu/...rer.c#line1846 it appears slide key characters are stored at key->label field with 1. no key is pressed (line 1857) at offset 0 and every subsequent key with 4 byte offset. 2. current_slide_key > 1 (line 1829) at offstet 4 * (key->current_slide_key - 1) % byte_count 3. I am not quite sure what this does (line 1839) But even if no key was pressed, at key->label[0] is no key char. The Keyboardlayout I use has a button with a slide key with 12 keys. The first character is not at offset 0 but at offset 56 and the next characters are at offset 56 + 16*x Whereas this "56" depends on number of slides (bytecount in structure vkb_key). Using a slide key with 6 keys (bytecount) this offet is 32. (offset = ((byte_count >> 1) + 1) << 3 But only after loading the vkb the first time. Changing the language, this memory location holds only garbage.