This commit redefines incrementing a combinedPos to either move a single
rune forward, *or* transition from EOL->BOL, *or* both. This allows traversal
of lines without a trailing newline character to reach the position after the
final glyph of content.
Additionally, this commit updates positionGreaterOrEqual to explicitly handle
hard newlines via special-case logic, allowing lines without a hard newline to
avoid the newline-based short-circuit logic that would prevent them from iteratively
reaching the combinedPos following the final glyph on the line.
Fixes: https://todo.sr.ht/~eliasnaur/gio/400
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit adds a test for the seekPosition helper, a function which can
be used to move a combinedPos forward through a body of text until it approaches
a position.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit adds an exhaustive test case for the positionGreaterOrEqual
helper function that our text widgets use to compare locations within
shaped text.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit adds documentation and tests for the clusterIndexFor helper,
making it easier to understand what it does and how to use it safely.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit restructures seekPosition from a complex state-manipulating
loop into a simple loop of iteratively applying an increment operation
to the combinedPos. The increment operation itself is now tested, and
much easier to understand.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
Chris Waldon