kc3-lang/libxkbcommon/test/modifiers.c

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Log

Author Commit Date CI Message
3031f6c3 2025-05-12 10:38:15 misc: Always use `unsigned` with `int` Better semantics & facilitate search.
7cd1180b 2025-05-06 11:07:47 modifiers: Add xkb_keymap_mod_get_mask() Added a dedicated API to query modifier masks rather than relying on a hack using `xkb_state_update_mask` and `xkb_state_serialize_mods`. Furthermore, this hack may not work in the future if we remove virtual mods resolution in `xkb_state_update_mask` to avoid corner-cases issues.
e00a5e83 2025-05-07 16:10:04 Add tests for pure virtual modifiers
dddffd51 2025-05-05 13:22:57 state: Fix virtual modifiers with non-real mod mapping Currently there are 2 issues with the handling of virtual modifiers in the keyboard state: 1. We assume that the input modifiers masks encode the indexes of all the modifiers of the keymap, but this is true only for the *real* modifiers (at least in xkbcommon and X11). Indeed, since the virtual modifiers *indexes* are implementation-specific, the input modifier masks merely *encode* the modifiers via their *mapping*. Consider the following keymap: ```c xkb_keymap { xkb_compat { virtual_modifiers M1 = 0x100; }; xkb_types { virtual_modifiers M2 = 0x200; }; }; ``` Now to illustrate, consider the following 2 implementation variants of libxkbcommon (assuming indexes 0-7 are the usual real modifiers): 1. Process `xkb_compat` then `xkb_types`. M1 and M2 have the respective indexes 8 and 9 and map to themselves (with the current assumption about mask denotation). 2. Process `xkb_types` then `xkb_compat`. M1 and M2 have the respective indexes 9 and 8 and map to each other. With the current `xkb_state_update_mask`, implementation 2 will swap M1 and M2 (compared to impl. 1) at each update! Indeed, we can see that `xkb_state_serialize_mods` doesn’t roundtrip via `xkb_state_update_mask`. 2. We assume that modifier masks use only bits denoting modifiers in the keymap, but when parsing the keymap we accept explicit virtual modifiers mapping of arbitrary values. E.g. if `M1` is the only virtual modifier and it is defined by: ```c virtual_modifiers M1 = 0x80000000; // 1 << (32 - 1) ``` then the 32th bit of a modifier mask input does *not* denote the 32th virtual modifier of the keymap, but merely the encoding of the mapping of `M1`. So when calling `xkb_state_update_mask`, we may discard some bits of the modifiers masks and end up with an incorrect state. These 2 issues may break interoperability with other implementations of XKB (e.g. kbvm) and make pure virtual modifiers handling fragile. We introduce the notion of *canonical state modifier mask*: the mask with the smallest population count that denotes all bits used to encode the modifiers in the keyboard state. It is equal to the bitwise OR of real modifiers mask and all the virtual modifiers mappings. This commit fixes the 2 issues by making *weaker* assumptions about the input modifier masks: 1. Modifiers may map to arbitrary values, not only real modifiers. 2. Input modifier masks merely encode modifiers via their *mapping*: - *real* modifiers map to themselves; - *virtual* modifiers map to the bitwise OR of their *explicit* mapping (via `virtual_modifiers`) and their *implicit* mapping (via keys’ real and virtual modmaps). - modifiers indexes are implementation-specific. Since the implementation before this commit also resolved virtual modifiers to their mappings, we continue doing so, but using only the bits that are *not* set in the canonical state modifier mask, so that we enable roundtrip of `xkb_state_serialize_mods` via `xkb_state_update_mask`. 3. Input modifier masks do not denote modifiers indexes (apart from real modifiers), so it is safe to discard only the bits that are not set in the canonical state modifier mask.
f8148744 2025-05-06 11:26:21 Define the mapping of real modifiers explicitly When querying for a modifier mapping, we should treat all modifiers equally. So simply store real modifier mapping as we do for the virtual ones. Also fixed useless boolean conversions.
e120807b 2025-01-29 15:35:22 Update license notices to SDPX short identifiers + update LICENSE Fix #628. Signed-off-by: Ran Benita <ran@unusedvar.com>
c7fdf506 2025-01-16 20:23:28 Use portable integer literal suffixes
2ba9daf1 2024-09-23 16:20:37 mods: Add more built-in names Added support for the following virtual modifiers: - `Alt` - `Meta` - `NumLock` - `Super` - `Hyper` - `LevelThree` - `LevelFive` - `ScrollLock`
086a286a 2024-09-23 16:20:17 mods: Always use constants from xkbcommon-names.h Respect the claim that real modifiers names are built-in: - Add `XKB_MOD_NAME_MOD[1-5]` constants. - Replace modifiers names with their corresponding constants.
e325e65e 2024-02-20 08:13:37 Add test_unit to all tests Currently it only ensure we do not buffer `stdout`.
5b5b67f2 2023-05-01 22:30:41 Add support for modmap None (#291) Unlike current xkbcommon, X11’s xkbcomp allows to remove entries in the modifiers’ map using “modifier_map None { … }”. “None” is translated to the special value “XkbNoModifier” defined in “X11/extensions/XKB.h”. Then it relies on the fact that in "CopyModMapDef", the following code: 1U << entry->modifier ends up being zero when “entry->modifier” is “XkbNoModifier” (i.e. 0xFF). Indeed, it relies on the overflow behaviour of the left shift, which in practice resolves to use only the 5 low bits of the shift amount, i.e. 0x1F here. Then the result of “1U << 0xFF” is cast to “char”, i.e. 0. This is a good trick but too magical, so in libxkbcommon we will use an explicit test against our new constant XKB_MOD_NONE.