diff options
author | Giuseppe D'Angelo <giuseppe.dangelo@kdab.com> | 2020-04-19 19:56:18 +0200 |
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committer | Giuseppe D'Angelo <giuseppe.dangelo@kdab.com> | 2020-09-03 07:00:31 +0200 |
commit | 25351dcc549f1daddf5e2ae8a242191174342a3e (patch) | |
tree | 97436200219470e7eee4096038e4da6e8df06835 /src/gui/platform/unix/qxkbcommon.cpp | |
parent | f03b2f7711e3a0e90fb21672273959a2a9ed1c38 (diff) |
Long live QKeyCombination!
C++20 via P1120 is deprecating arithmetic operations between
unrelated enumeration types, and GCC 10 is already complaining.
Hence, these operations might become illegal in C++23 or C++26 at
the latest.
A case of this that affects Qt is in key combinations: a
QKeySequence can be constructed by summing / ORing modifiers and a
key, for instance:
Qt::CTRL + Qt::Key_A
Qt::SHIFT | Qt::CTRL | Qt::Key_G (recommended, see below)
The problem is that the modifiers and the key belong to different
enumerations (and there's 2 enumerations for the modifier, and one
for the key).
To solve this: add a dedicated class to represent a combination of
keys, and operators between those enumerations to build instances
of this class.
I would've simply defined operator|, but again docs and pre-existing
code use operator+ as well, so added both to at least tackle simple
cases (modifier + key).
Multiple modifiers create a problem: operator+ between them yields
int, not the corresponding flags type (because operator+ is not
overloaded for this use case):
Qt::CTRL + Qt::SHIFT + Qt::Key_A
\__________________/ /
int /
\______________/
int
Not only this loses track of the datatypes involved, but it would
also then "add" the key (with NO warnings, now its int + enum, so
it's not mixing enums!) and yielding int again.
I don't want to special-case this; the point of the class is
that int is the wrong datatype. Everything works just fine when
using operator| instead:
Qt::CTRL | Qt::SHIFT | Qt::Key_A
\__________________/ /
Qt::Modifiers /
\______________/
QKeyCombination
So I'm defining operator+ so that the simple cases still work,
but also deprecating it.
Port some code around Qt to the new class. In certain cases,
it's a huge win for clarity. In some others, I've just added
the necessary casts to make it still compile without warnings,
without attempting refactorings.
[ChangeLog][QtCore][QKeyCombination] New class to represent
a combination of a key and zero or more modifiers, to be used
when defining shortcuts or similar.
[ChangeLog][Potentially Source-Incompatible Changes] A keyboard
modifier (such as Qt::CTRL, Qt::AltModifier, etc.) should be
combined with a key (such as Qt::Key_A, Qt::Key_F1, etc.) by using
operator|, not operator+. The result is now an object of type
QKeyCombination, that stores the key and the modifiers.
Change-Id: I657a3a328232f059023fff69c5031ee31cc91dd6
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Diffstat (limited to 'src/gui/platform/unix/qxkbcommon.cpp')
-rw-r--r-- | src/gui/platform/unix/qxkbcommon.cpp | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/src/gui/platform/unix/qxkbcommon.cpp b/src/gui/platform/unix/qxkbcommon.cpp index ff19ebd5d5..71f1cfd24a 100644 --- a/src/gui/platform/unix/qxkbcommon.cpp +++ b/src/gui/platform/unix/qxkbcommon.cpp @@ -656,7 +656,7 @@ QList<int> QXkbCommon::possibleKeys(xkb_state *state, const QKeyEvent *event, int baseQtKey = keysymToQtKey_internal(sym, modifiers, queryState, keycode, superAsMeta, hyperAsMeta); if (baseQtKey) - result += (baseQtKey + modifiers); + result += (baseQtKey + int(modifiers)); xkb_mod_index_t shiftMod = xkb_keymap_mod_get_index(keymap, "Shift"); xkb_mod_index_t altMod = xkb_keymap_mod_get_index(keymap, "Alt"); @@ -711,7 +711,7 @@ QList<int> QXkbCommon::possibleKeys(xkb_state *state, const QKeyEvent *event, if (ambiguous) continue; - result += (qtKey + mods); + result += (qtKey + int(mods)); } } |