[PATCH libxkbcommon 2/4] compose: add xkbcommon-compose - implementation

[David Herrmann]

Hi

On Sun, Sep 14, 2014 at 11:05 PM, Ran Benita <ran234 at gmail.com> wrote:
> Signed-off-by: Ran Benita <ran234 at gmail.com>
> ---

[snip]

> diff --git a/src/compose/state.c b/src/compose/state.c
> new file mode 100644
> index 0000000..06e4ce5
> --- /dev/null
> +++ b/src/compose/state.c
> @@ -0,0 +1,196 @@
> +/*
> + * Copyright © 2013 Ran Benita <ran234 at gmail.com>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * the rights to use, copy, modify, merge, publish, distribute, sublicense,
> + * and/or sell copies of the Software, and to permit persons to whom the
> + * Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> + * DEALINGS IN THE SOFTWARE.
> + */
> +
> +#include "table.h"
> +#include "utils.h"
> +#include "keysym.h"
> +
> +struct xkb_compose_state {
> +    int refcnt;
> +    enum xkb_compose_state_flags flags;
> +    struct xkb_compose_table *table;
> +
> +    /*
> +     * Offsets into xkb_compose_table::nodes.
> +     *
> +     * They maintain the current and previous position in the trie; see
> +     * xkb_compose_state_feed().
> +     *
> +     * This is also sufficient for inferring the current status; see
> +     * xkb_compose_state_get_status().
> +     */
> +    uint32_t prev_context;
> +    uint32_t context;
> +};
> +
> +XKB_EXPORT struct xkb_compose_state *
> +xkb_compose_state_new(struct xkb_compose_table *table,
> +                      enum xkb_compose_state_flags flags)
> +{
> +    struct xkb_compose_state *state;
> +
> +    state = calloc(1, sizeof(*state));
> +    if (!state)
> +        return NULL;
> +
> +    state->refcnt = 1;
> +    state->table = xkb_compose_table_ref(table);
> +
> +    state->flags = flags;
> +    state->prev_context = 0;
> +    state->context = 0;
> +
> +    return state;
> +}
> +
> +XKB_EXPORT struct xkb_compose_state *
> +xkb_compose_state_ref(struct xkb_compose_state *state)
> +{
> +    state->refcnt++;
> +    return state;
> +}
> +
> +XKB_EXPORT void
> +xkb_compose_state_unref(struct xkb_compose_state *state)
> +{
> +    if (!state || --state->refcnt > 0)
> +        return;
> +
> +    xkb_compose_table_unref(state->table);
> +    free(state);
> +}
> +
> +XKB_EXPORT struct xkb_compose_table *
> +xkb_compose_state_get_compose_table(struct xkb_compose_state *state)
> +{
> +    return state->table;
> +}
> +
> +XKB_EXPORT enum xkb_compose_feed_result
> +xkb_compose_state_feed(struct xkb_compose_state *state, xkb_keysym_t keysym)
> +{
> +    uint32_t context;
> +    const struct compose_node *node;
> +
> +    /*
> +     * Modifiers do not affect the sequence directly.  In particular,
> +     * they do not cancel a sequence; otherwise it'd be impossible to
> +     * have a sequence like <dead_acute><A> (needs Shift in the middle).
> +     *
> +     * The following test is not really accurate - in order to test if
> +     * a key is "modifier key", we really need the keymap, but we don't
> +     * have it here.  However, this is (approximately) what libX11 does
> +     * as well.
> +     */
> +    if (xkb_keysym_is_modifier(keysym))
> +        return XKB_COMPOSE_FEED_IGNORED;

Why don't we require a keymap in xkb_compose_state_new()? Should be
easy to do and we can then track modifiers reliably.
Ok, a keysym which is a modifier in one keymap should never be a
normal key in another.. unlike keycodes. But I don't see why we need
to rely on that when we can just take a keymap.

Otherwise, looks good (I didn't read through the parser, though).

Thanks
David