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Diffstat (limited to 'src/draglock.h')
| -rw-r--r-- | src/draglock.h | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/src/draglock.h b/src/draglock.h new file mode 100644 index 0000000..90a71b9 --- /dev/null +++ b/src/draglock.h @@ -0,0 +1,161 @@ +/* + * SPDX-License-Identifier: MIT + * + * Copyright © 2015 Red Hat, Inc. + * + * 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. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#ifndef DRAGLOCK_H +#define DRAGLOCK_H 1 + +#include <stdbool.h> +#include <stdlib.h> + +/* 32 buttons are enough for everybody™ + * Note that this is the limit of physical buttons as well as the highest + * allowed target button. + */ +#define DRAGLOCK_MAX_BUTTONS 32 + +enum draglock_mode +{ + DRAGLOCK_DISABLED, + DRAGLOCK_META, + DRAGLOCK_PAIRS +}; + +enum draglock_button_state +{ + DRAGLOCK_BUTTON_STATE_NONE, + DRAGLOCK_BUTTON_STATE_DOWN_1, + DRAGLOCK_BUTTON_STATE_UP_1, + DRAGLOCK_BUTTON_STATE_DOWN_2, +}; + +struct draglock +{ + enum draglock_mode mode; + int meta_button; /* meta key to lock any button */ + bool meta_state; /* meta_button state */ + unsigned int lock_pair[DRAGLOCK_MAX_BUTTONS + 1];/* specify a meta/lock pair */ + enum draglock_button_state lock_state[DRAGLOCK_MAX_BUTTONS + 1]; /* state of any locked buttons */ +}; + +/** + * Initialize the draglock struct based on the config string. The string is + * either a single number to configure DRAGLOCK_META mode or a list of + * number pairs, with pair[0] as button and pair[1] as target lock number to + * configure DRAGLOCK_PAIRS mode. + * + * If config is NULL, the empty string, "0" or an even-numbered list of 0, + * the drag lock mode is DRAGLOCK_DISABLED. + * + * @return 0 on success or nonzero on error + */ +int +draglock_init_from_string(struct draglock *dl, const char *config); + +/** + * Get the current drag lock mode. + * + * If the mode is DRAGLOCK_META, a meta button click will cause the next + * subsequent button click to be held logically down until the release of + * the second button click of that same button. Events from the meta button + * are always discarded. + * + * If the mode is DRAGLOCK_PAIRS, any button may be configured with a + * 'target' button number. A click of that button causes the target button + * to be held logically down until the release of the second button click. + */ +enum draglock_mode +draglock_get_mode(const struct draglock *dl); + +/** + * @return the meta button number or 0 if the current mode is not + * DRAGLOCK_META. + */ +int +draglock_get_meta(const struct draglock *dl); + +/** + * Get the drag lock button mapping pairs. The array is filled with the + * button number as index and the mapped target button number as value, i.e. + * array[3] == 8 means button 3 will draglock button 8. + * + * A value of 0 indicates draglock is disabled for that button. + * + * @note Button numbers start at 1, array[0] is always 0. + * + * @param[in|out] array Caller-allocated array to hold the button mappings. + * @param[in] nelem Maximum number of elements in array + * + * @return The number of valid elements in array or 0 if the current mode is + * not DRAGLOCK_PAIRS + */ +size_t +draglock_get_pairs(const struct draglock *dl, int *array, size_t nelem); + +/** + * Set the drag lock config to the DRAGLOCK_META mode, with the given + * button as meta button. + * + * If the button is 0 the mode becomes DRAGLOCK_DISABLED. + * + * @return 0 on success, nonzero otherwise + */ +int +draglock_set_meta(struct draglock *dl, int meta_button); + +/** + * Set the drag lock config to the DRAGLOCK_PAIRS mode. The array + * must be filled with the button number as index and the mapped target + * button number as value, i.e. + * array[3] == 8 means button 3 will draglock button 8. + * + * A value of 0 indicates draglock is disabled for that button. If all + * buttons are 0, the mode becomes DRAGLOCK_DISABLED. + * + * @note Button numbers start at 1, array[0] is always 0. + * + * @return 0 on successor nonzero otherwise + */ +int +draglock_set_pairs(struct draglock *dl, const int *array, size_t nelem); + +/** + * Process the given button event through the drag lock state machine. + * If the event is to be discarded by the caller, button is set to 0. + * Otherwise, button is set to the button event to process and is_press is + * set to the button state to process. + * + * @param[in|out] button The button number to process + * @param[in|out] is_press nonzero for press, zero for release + * + * @return 0 on success or 1 on error + */ +int +draglock_filter_button(struct draglock *dl, int *button, int *is_press); + +#endif /* DRAGLOCK_H */ |