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>
This commit switches the way in which the editor and helper functions check
for RTL text from a heuristic to using the actual text direction.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit adds methods to widget.Scrollbar that enable consuming
code to check if the scroll indicator is processing a drag gesture
or if the scroll track is currently being hovered. These accessors
enable scrollbar style types to have enough information to hide the
scroll indicator when it isn't needed, whereas currently they cannot
differentiate between a scrollbar indicator that is being dragged
but hasn't moved since the last frame and a scrollbar indicator that
is not being dragged.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
Before this change, an IME text edit would always have its newlines
replaced with spaces. However, for Editors where Submit is enabled
we want newlines to result in SubmitEvents.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This commit adds a simple linear-history undo/redo mechanism to
widget.Editor bound to Short-(Shift)-Z as well as tests for this
new feature.
Notes on the implementation:
- using a slice to hold the history does mean that we incur
allocations as the user types, but I hope that the Go slice
growth heuristic means that the number of times we pay this
penalty is very small. We also never shrink the slice in this
implementation, which ensures that undoing work and then making
additional modifications is very efficient, but could be framed
as a memory leak.
- this implementation creates a new history element every time
we call replace(). This means that, on desktop, it's essentially
one per rune of input. Users likely want to be able to undo larger
units of change, so a future improvement could be to coalesce
changes so long as the selection doesn't change between them.
- I think it's possible to store only one of the Apply/Reverse
change contents in the history slice, but it's significantly
more complicated. To implement this, you'd need to add a field
indicating if the modification represented a forward or backward
change, and then rewrite the modification's content as you performed
undo/redo operations.For the time being, I'm not sure it's worth
this complexity.
- Future work could introduce a limit to the number of history
entries stored. If we did this, we should also change the
data structure for storing history. Enforcing such a limit
using a simple slice like this would be extremely inefficient.
Perhaps a ring buffer or a linked list would make more sense?
- Applications will likely want to be able to manipulate undo
history in the future. We may wish to export undo() and redo()
from the editor. Applications will also likely want a mechanism
to save the undo history to disk and restore it (implementing
persistent undo). I'm not sure what the most suitable API for
that is yet, so I decided not to try to tackle it yet.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
Previously, we'd scroll so the new viewportStart corresponded to the
clicked position. This felt okay if clicking above the current
indicator, but felt jarring when clicking below it. Centering gives a
consistent behavior regardless of the scroll direction.
Signed-off-by: Dominik Honnef <dominik@honnef.co>
Before, we would set s.dragging to false on pointer.Release and then
immediately set it back to true because we were processing the event and
saw that s.dragging was false.
Signed-off-by: Dominik Honnef <dominik@honnef.co>
Once the user begins dragging, the cursor can move outside the clip
area (or even the window on at least X11), leading to events with
positions that are either negative, or larger than the clip area.
Negative values outright break the delta tracking and cause the
scrollbar to misbehave. Positive values "only" break the invariant of
Scrollbar.ScrollDistance that the returned value is in the range [-1, 1].
Signed-off-by: Dominik Honnef <dominik@honnef.co>
The app.Window.Perform(ActionMove) is the wrong abstraction for
initiating a move gesture: Windows needs to know the move gesture
area at pointer move, and macOS needs to know the pointer button
down event that triggers the move gesture. This change replaces
Perform(ActionMove) with a new system.ActionInputOp that marks an
area movable.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Allowing clients to initiate resize gestures is a waste: macOS
doesn't support them, and the only reason we added them was to
implement client-side decorations for Wayland. Now all desktop
platforms implement resize gestures as needed, and we no longer
need the system.Action actions.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Style values are ephemeral, and pointer methods can't be called in
the same expression a style value is constructed. Matches other style
types.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
The unit.Value is a struct and thus more inconvenient to use than its
underlying float32 type. In addition, most uses don't need a general
value, but rather a specific unit given by the context. This change
replaces unit.Value with two float32 units, Dp and Sp. It also changes
variables and parameters of unit.Value to a specific unit type matching
the context. That is, unit.Dp everywhere except for text sizes which are
in Sp.
Switching to typed float32s has multiple advantages
- They can be constants:
const touchSlop = unit.Dp(16)
- Casting untyped constants is no longer necessary:
insets := layout.UniformInset(16)
- Calculation with values is natural:
func (s ScrollbarStyle) Width() unit.Dp {
return s.Indicator.MinorWidth + s.Track.MinorPadding + s.Track.MinorPadding
}
The main API change is that calls to gtx.Px must be replaced with either
gtx.Dp or gtx.Sp depending on the unit.
Idea by Christophe Meessen.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Like the change to op.Offset before this, clip.RRect and UniformRRect
is usually used with integer coordinates. Change to integer coordinates
to eliminate many useless conversions to float32.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
op.Offset is a convenience function most often used by layouts. Layouts
usually operate in integer coordinates, and the float32 version of op.Offset
needlessly force conversions from int to float32. This change makes op.Offset
take integer coordinates, to better match its intended use.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Most widget code operate in integer coordinates. This change makes
gesture pointer coordinates integer, to lessen the number of float32
to int conversions.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This commit fixes a visual-only bug in the ListStyle that could
make the scrollbar float at the edge of the maximum constraints
when the list did not occupy the full constraints. The list
would still reserve layout space for the scrollbar in the correct
position, but the scrollbar would not be displayed there.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
Previously, a bug in the ListStyle could result in items being
passed a negative value in the minimum constraints.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
Android doesn't distinguish between the arrow keys on a keyboard and the
directional keys on a remote control, so there's no way to move the caret
in an Editor with arrow keys. This change updates the Android port to map
Android's DPAD_* key codes to the arrow key names, fixing caret movement.
The change also updates Editor to only request arrow keys that actually move
the caret, to keep directional focus movement working.
Fixes: https://todo.sr.ht/~eliasnaur/gio/410
Signed-off-by: Mearaj <mearajbhagad@gmail.com>
Prior to this change an editor with no content and a zero minimum
constraint would return itself has having width zero. This
prevented users from being able to see the editor when they
moved focus to it, as it could not display its caret. This
simple change ensures that, at minimum, the editor returns
its dimensions to include the width of a caret.
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
If the currently focused handler don't want the key event, try every
other handler, from top to bottom. This change requires widgets to
only react when focused.
Fixes: https://todo.sr.ht/~eliasnaur/gio/406
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Before this change, every Event would be passed to the focused InputOp
tag, making it impossible to implement, say, program-wide shortcuts.
This change implements key.Event routing similar to how pointer.Events
are routed: every InputOp describes the set of keys it can handle, and
the router use that information to deliver an Event to the matching
handler.
This is an API change, because every InputOp must now include a filter
matching the keys it wants to handle.
Fixes: https://todo.sr.ht/~eliasnaur/gio/395
Signed-off-by: Elias Naur <mail@eliasnaur.com>
A meaningful clip area for a key handler will matter when we start
auto-scrolling to move focused handlers into view.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
This commit ensures that text.Alignment is intuitive for
the direction of the text being aligned. RTL text with
Alignment Start will be aligned to the right edge of the area,
whereas LTR text with Alignment Start will continue to be
aligned to the left edge. Vice versa for the End alignment.
References: https://todo.sr.ht/~eliasnaur/gio/146
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit switches gofont.Collection from returning
a collection of fonts using the old text shaper to
using the new harfbuzz-based shaper. The underlying type
of gofont.Collection() has changed, which may break users
who dug into the font data.
References: https://todo.sr.ht/~eliasnaur/gio/146
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
These fields are no longer needed with the new text shaper.
Advances is redundant to the glyph information, and Text
should never be used during layout, as you should
traverse the cluster list instead. This commit also removed
the now-unused string field from the path LRU cache key.
References: https://todo.sr.ht/~eliasnaur/gio/146
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit replaces the previous opentype.Font with
an implementation that uses the new text shaper. In
order to keep the implementation simple, support for
opentype font collections was dropped. It should be
possible to re-add this support after some changes
to the text shaper's line wrapping algorithm.
To expand on the above, doing proper font fallback with
harfbuzz will require splitting the input text on font
glyph support boundaries, changing the input from a
simple shaping.Input to []shaping.Input with each input
matched against the font that supports its language.
The line wrapping then needs to be able to properly
consume that slice. Since the line wrapping algorithm is
really complex, I'm hoping to defer that modification
until this simple version is accepted.
References: https://todo.sr.ht/~eliasnaur/gio/146
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit updates material.Editor and material.Label to support the
new text shaper. This requires breaking their assumption that glyphs
of font data map 1:1 to runes of text data.
References: https://todo.sr.ht/~eliasnaur/gio/146
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
This commit introduces a new text shaping infrastructure
powered by Benoit Kugler's Go source-port of harfbuzz.
This shaper can properly display complex scripts and RTL
text. This commit changes the signature of the text.Shaper
function, which is a breaking API change.
The new functionality is available via opentype.ParseHarfbuzz,
which configures a text.Shaper leveraging the new backend.
References: https://todo.sr.ht/~eliasnaur/gio/146
Signed-off-by: Chris Waldon <christopher.waldon.dev@gmail.com>
Chris Waldon