* Add support for CSS conic-gradient 'from <angle>' syntax
Implement rotation support for conic gradients by adding the 'from <angle>'
syntax, which rotates the entire gradient by the specified angle.
- Add `from_angle` field to ConicGradient expression
- Parse 'from <angle>' syntax in compiler (defaults to 0deg when omitted)
- Normalize angles to 0-1 range (0.0 = 0°, 1.0 = 360°)
- Add `ConicGradientBrush::rotated_stops()` method that:
* Applies rotation by adding from_angle to each stop position
* Adds boundary stops at 0.0 and 1.0 with interpolated colors
* Handles stops outside [0, 1] range for boundary interpolation
- Update all renderers (Skia, FemtoVG, Qt, Software) to use rotated_stops()
The rotation is applied at render time by the rotated_stops() method,
which ensures all renderers consistently handle the gradient rotation.
* Add screenshot to rotated conic gradient docs example
Wraps the rotated conic gradient example in CodeSnippetMD to automatically
generate and display a visual screenshot of the gradient rotation effect.
This makes it easier for users to understand how the 'from' parameter rotates
the gradient.
* Make ConicGradientBrush fields private
The from_angle and stops fields don't need to be pub since:
- Rust code in the same module can access them without pub
- C++ FFI access works through cbindgen-generated struct (C++ struct members are public by default)
* Optimize ConicGradientBrush::rotated_stops to avoid allocations
- Changed return type from Vec to SharedVector
- When from_angle is zero, returns a clone of internal SharedVector
(only increments reference count instead of allocating new Vec)
- Removed break from duplicate position separation loop to handle
all duplicate pairs, not just the first one
- Updated documentation to match actual implementation
* Remove automatic sorting in ConicGradientBrush::new() to match CSS spec
- CSS conic-gradient does not automatically sort color stops
- Stops are processed in the order specified by the user
- Changed boundary stop interpolation logic to use max_by/min_by
instead of relying on sorted order
- This allows CSS-style hard transitions when stops are out of order
* Move conic gradient rotation processing to construction time
Major changes:
- ConicGradientBrush::new() now applies rotation and boundary stop
processing immediately, instead of deferring to rotated_stops()
- Removed rotated_stops() method - backends now use stops() directly
- Changed to LinearGradientBrush pattern: store angle in first dummy stop
- Added angle() method to retrieve the stored angle
- Maintained #[repr(transparent)] by removing from_angle field
- All backends updated: rotated_stops() -> stops()
- Qt backend
- Skia renderer
- femtovg renderer
- Software renderer
C++ API changes:
- Added FFI function slint_conic_gradient_new() for C++ to call Rust's new()
- Updated make_conic_gradient() to call FFI function instead of manually
constructing SharedVector
- Ensures C++-created gradients get full rotation processing
Benefits:
- Eliminates per-frame rotation calculations
- Reduces memory usage (no from_angle field)
- Consistent with LinearGradientBrush design
- C++ and Rust APIs now produce identical results
* Change ConicGradientBrush::new() from_angle parameter to use degrees
- Changed from_angle parameter from normalized form (0.0-1.0) to degrees
- Matches LinearGradientBrush API convention (angle in degrees)
- Updated internal conversion: from_angle / 360.0 for normalization
- Stores angle as-is in degrees in the first dummy stop
- FFI function slint_conic_gradient_new() passes degrees directly
Example usage:
ConicGradientBrush::new(90.0, stops) // 90 degrees
LinearGradientBrush::new(90.0, stops) // 90 degrees (consistent)
* Fix ConicGradient color transformation methods to preserve angle
Changed brighter(), darker(), transparentize(), and with_alpha() methods
to clone and modify the gradient in-place instead of calling new().
- Clones the existing gradient (preserves angle and rotation)
- Modifies only color stops (skips first stop which contains angle)
- Avoids re-running expensive rotation processing
- Maintains the original angle information
Before: ConicGradientBrush::new(0.0, ...) // Lost angle information
After: Clone + modify colors in-place // Preserves angle
* Use premultiplied alpha interpolation for conic gradient colors
- Changed interpolate_color() to use premultiplied RGBA interpolation
- Updated signature to match Color::mix convention (&Color, factor)
- Added documentation explaining why we can't use Color::mix() here
(Sass algorithm vs CSS gradient color interpolation)
- Reference: https://www.w3.org/TR/css-images-4/#color-interpolation
This ensures correct visual interpolation of semi-transparent colors
in gradient boundaries, following CSS gradient specification.
* Run rustfmt on conic gradient code
* Fix ConicGradientBrush edge cases and add comprehensive tests
- Handle stops that are all below 0.0 or all above 1.0
- Add default transparent gradient when no valid stops remain
- Add 7 unit tests covering basic functionality and edge cases
* Apply clippy suggestion: use retain() instead of filter().collect()
* Fix radial-gradient parsing to allow empty gradients
Allow @radial-gradient(circle) without color stops, fixing syntax test
regression from commit 820ae2b04.
The previous logic required a comma after 'circle', but it should only
error if there's something that is NOT a comma.
* Fix conic-gradient syntax test error markers
Update error markers to match actual compiler error positions.
The 'from 2' case produces two errors:
- One at the @conic-gradient expression level
- One at the literal '2' position
Auto-updated using SLINT_SYNTAX_TEST_UPDATE=1.
* Refactor ConicGradientBrush epsilon adjustment and update tests
- Move epsilon adjustment for first stop into rotation block
(only needed when rotation is applied)
- Update property_view test to reflect boundary stops added by
ConicGradientBrush::new()
* Update conic-gradient screenshot reference image
Update the reference screenshot to match the current rendering output.
The small pixel differences (1% different pixels, max color diff 3.46)
are due to minor rounding differences in the conic gradient implementation.
* Fix ConicGradientBrush C++ FFI to avoid C-linkage return type error
Refactored ConicGradientBrush construction to match LinearGradientBrush
pattern, fixing macOS Clang error about returning C++ types from extern "C"
functions.
Changes:
- Rust: Split ConicGradientBrush::new into simple construction + separate
normalize_stops() and apply_rotation() methods
- Rust: Added FFI functions slint_conic_gradient_normalize_stops() and
slint_conic_gradient_apply_rotation() that take pointers (no return value)
- C++: Construct SharedVector directly in make_conic_gradient(), then call
Rust functions via pointer (matching LinearGradientBrush pattern)
- Optimized both methods to only copy when changes are needed
This resolves the macOS Clang error:
"'slint_conic_gradient_new' has C-linkage specified, but returns incomplete
type 'ConicGradientBrush' which could be incompatible with C"
The new approach maintains ABI compatibility while keeping complex gradient
processing logic in Rust.
* Fix C++ header generation to avoid GradientStop redefinition error
Resolves the macOS CI compilation error where GradientStop and
ConicGradientBrush were being defined in multiple headers
(slint_color_internal.h, slint_image_internal.h, and slint_brush_internal.h).
Changes:
- cbindgen.rs: Add ConicGradientBrush and FFI functions to slint_brush_internal.h include list
- cbindgen.rs: Add GradientStop, ConicGradientBrush, and FFI functions to exclude list for other headers
- slint_color.h: Add forward declaration for ConicGradientBrush
- slint_color.h: Add friend declaration for ConicGradientBrush to allow access to Color::inner
Root cause: After adding extern "C" functions in graphics/brush.rs,
cbindgen automatically detects and tries to include them in all headers
that use graphics/brush.rs as a source. The exclude list + filter logic
ensures these types only appear in slint_brush_internal.h.
This fixes the C++ compilation errors:
- "redefinition of 'GradientStop'"
- "ConicGradientBrush does not name a type"
- "Color::inner is private within this context"
* Prepare ConicGradientBrush FFI for Rust 2024 edition
Update FFI functions to use the new `#[unsafe(no_mangle)]` attribute
syntax and safe function signatures in preparation for Rust 2024 edition.
- Add `#![allow(unsafe_code)]` to graphics module for `#[unsafe(no_mangle)]`
- Add `#[cfg(feature = "ffi")]` to conditionally compile FFI functions
- Change from raw pointers to safe references (&mut)
- Remove manual null checks and unsafe blocks
I kept seeing distracting warnings when working with these testcases,
and it's better to have good examples when writing new testcases.
I didn't touch the issue_*.slint regression tests, so those will
still be testing the old syntax.
Rename grid to grid_simple, otherwise
cargo test -p test-driver-interpreter -- test_interpreter_layout_grid
runs multiple tests, no way to run only that one.
Same for nested_grid.slint given that there's a nested_grid_2.slint
* Change Color type to be f32 internally but no other changes
* Add missing clamp
* Add round function as we're not on MSRV 1.90+
* Prepare for being able to switch between u8s and f32s
* [autofix.ci] apply automated fixes
* Fix Display impl
* Add feature flag for 8-bit color values. Name to be bikeshed
* Fix brighter-darker test
* Update test screenshot
* Remove unused Float trait import
* Add cfg thing for not(cbindgen)
* Change Channel to float in cbindgen
* Change the cpp color type for uint8_t for now
* Opt cpp into 8-bit-color
* Switch feature around
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
This line was added by mistake in a previous commit.
But the feature can't work for C++ and the interpreter for now because
they can't re-use the same binding.
It would also break for eust if there was another layer of two way
binding.
That's because `impl BindingCallable for TwoWayBindingWithMap` doesn't
(and can't) implement intercept_set_binding
The previous code would create many many lambda and if conditions which
would cause nesting to be way too high for big enums.
Also improve the C++ codegen for condition to use the ternary operator
when possible
Fixes#9954
* Add `stroke-line-join` for `Path`
* Add `LineJoin` enum
* Add `stroke-line-join` property for `Path`
* Set line_join in Skia and FemtoVG renders
* Set pen_join_style in Qt backend
* Add example test case
* Docs: Add `stroke-line-join` property for `Path`
... when there are two level of indirection, as it is the case with the
interpreter as it tries to create mapping to Value as one first level of
indirection
Implement a "scroll to make points visible" function to Flickable, automatically scroll to the bounding box of an element when it gains focus.
ChangeLog: When resizing the window, try to keep the focus item visible if it's in a Flickable.
ChangeLog: When focusing an element that's not fully visible, try to scroll a parent Flickable so that it is.
Fixes#3067
* tests: Add a test for another popup-induced panic
* compiler(rust): Make popup window opening and closing more robust
Do not make the generated rust code trigger a panic when the parent no
longer exists.
Fixes: #9722 (rust only)
Co-authored-by: Olivier Goffart <olivier.goffart@slint.dev>
As brought up in 7d038eb9e2, the bug
I was fixing should really have a test for it - so I added one.
Testing the scrolled callback is a bit odd to handle because not
only does each style have a different scroll handle but it's a bit
dubious when/how many scrolled callback emissions there should be.
I was able to find a sweet spot for both of these problems, and
although the test case is a bit vague it does catch when a style
doesn't emit the callback.
* Tools: Remove the unecessary 'FF' from generated colors
When colors in most UI tools are 100% alpha the extra 'FF' is auto cut
off for readability. e.g. #000000FF becomes #000000. Since introducing
the new color pickers this has been the case on the UI side. However the
code generator for gradients was inconsistent and would still add in the
unnecessary 'FF'. This fixes that and makes generated gradient code
tidier.
* Fix correct tests
* Fix
* [autofix.ci] apply automated fixes
* Fix
* Fix
* Fix
---------
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Some warning about unused variable may not be worth trying to silence in
generated code because they usually come from buggy code in the first
place (useless statements)
So whitelist these warning from the test
In code-blocks, only the final expressions value is actually used. All
other expressions must have side effects or are otherwise useless.
This usually indicates an error by the programmer, so emit a warning to
notify the programmer about the issue.
Closes#4954
Example from the associated issue:
This Slint code
```slint
FocusScope {
key-pressed(event) => {
if (event.text == "a") {
accept
}
reject
}
}
```
Looks like it would return accept, but in fact, the statement has no effect.
Changelog: The slint compiler now emits a warning if a statement is without effect
- Respect the padding even for empty layouts
- When there is a non-default alignment, layouts shouldn't have a
max size: Fix the case for empty layout
- Remove max constraint in the orthogonal direction of an empty layout
To implement an external Slint library, the types and components implemented
in the .slint files needs to be exposed through the Rust crate.
A simple example example/app-library is added to demonstrate how to use this feature.
CC #7060
