Is Slint compatible with the espressif command line tool?

[pej-p]

I've been struggling to find a way to build and flash a slint project for the esp32s3 (Lilygo t-display s3). Currently I'm trying with the idf.py tool from espressif. CMakeLists.txt looks as following;

cmake_minimum_required(VERSION 3.21)
include($ENV{IDF_PATH}/tools/cmake/project.cmake)
project(ui LANGUAGES CXX)

find_package(Slint QUIET)
if (NOT Slint_FOUND)
  message("Slint could not be located in the CMake module search path. Downloading it from Git and building it locally")
  include(FetchContent)
  FetchContent_Declare(
    Slint
    GIT_REPOSITORY https://github.com/slint-ui/slint.git
    # `release/1` will auto-upgrade to the latest Slint >= 1.0.0 and < 2.0.0
    # `release/1.0` will auto-upgrade to the latest Slint >= 1.0.0 and < 1.1.0
    GIT_TAG release/1
    SOURCE_SUBDIR api/cpp
  )
  FetchContent_MakeAvailable(Slint)
endif (NOT Slint_FOUND)

add_executable(ui main/main.cpp)
slint_target_sources(ui main/main.slint)
target_link_libraries(ui PRIVATE Slint::Slint)
# On Windows, copy the Slint DLL next to the application binary so that it's found.
if (WIN32)
    add_custom_command(TARGET ui POST_BUILD COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_RUNTIME_DLLS:ui> $<TARGET_FILE_DIR:ui> COMMAND_EXPAND_LISTS)
endif()

If I keep CMakeLists that way, the header file won't be generated in time and I'll get an include error;

-c /home/user/esp/ui/main/main.cpp
/home/user/esp/ui/main/main.cpp:1:10: fatal error: ../build/main.h: No such file or directory
    1 | #include "../build/main.h"
      |          ^~~~~~~~~~~~~~~~~
compilation terminated.
[924/938] Building C object esp-idf/wi...ifi_provisioning.dir/src/manager.c.objninja: build stopped: subcommand failed.

if I move the include($ENV{IDF_PATH}/tools/cmake/project.cmake) the binary will actually be built and is executable, however flashing fails due to a missing file in the build/ directory.

So is it possible to build/flash Slint projects with idf.py? If not, can you point me towards an alternative?

[tronical]

I've never tried to build with idf.py - I've only used the Rust build of Slint on bare metal, without idf. I'm a little sceptical that this can be made to work, but on the other hand it looks like you've come rather far. What should happen with slint_target_sources(ui main/main.slint) is that a rule is generated to invoke the slint-compiler binary to create main.h in the build directory from main.slint - and your main.cpp includes it. What happens if you run ninja main.h in your build directory? Does the file get created?

[pej-p]

I'd also like to try without idf, can you give me instructions on how to do so?

[tronical]

For the Rust build without idf, you can find instructions for ESP32 S3 here: https://github.com/slint-ui/slint/tree/master/examples/mcu-board-support#esp32 . Those are for the S3 Box, so it will most probably not work out of the box on your device. But the code in there might be adaptable, and you can read about the general concept of how to use Slint's Rust API on any MCU here: https://github.com/slint-ui/slint/blob/master/api/rs/slint/mcu.md

[pej-p]

I have trouble executing the command

~/slint$ cargo +esp build -p printerdemo_mcu --target xtensa-esp32s3-none-elf --no-default-features --features=mcu-board-support/esp32-s3-box --release --config examples/mcu-board-support/esp32_s3_box/cargo-config.toml

due to the following dependency conflict;

    Updating crates.io index
error: failed to select a version for `skia-bindings`.
    ... required by package `skia-safe v0.60.0`
    ... which satisfies dependency `skia-safe = "^0.60"` of package `i-slint-renderer-skia v1.0.0`
    ... which satisfies dependency `i-slint-renderer-skia = "=1.0.0"` of package `i-slint-backend-winit v1.0.0`
    ... which satisfies dependency `i-slint-backend-winit = "=1.0.0"` of package `i-slint-backend-selector v1.0.0`
    ... which satisfies dependency `i-slint-backend-selector = "=1.0.0"` of package `slint v1.0.0`
    ... which satisfies dependency `slint = "^1.0.0"` of package `printerdemo_mcu v1.0.3 (/home/user/slint/examples/printerdemo_mcu)`
versions that meet the requirements `=0.60.0` are: 0.60.0

the package `skia-bindings` links to the native library `skia`, but it conflicts with a previous package which links to `skia` as well:
package `skia-bindings v0.62.0`
    ... which satisfies dependency `skia-bindings = "=0.62.0"` (locked to 0.62.0) of package `skia-safe v0.62.0`
    ... which satisfies dependency `skia-safe = "^0.62"` (locked to 0.62.0) of package `i-slint-renderer-skia v1.0.3 (/home/user/slint/internal/renderers/skia)`
    ... which satisfies path dependency `i-slint-renderer-skia` (locked to 1.0.3) of package `i-slint-backend-winit v1.0.3 (/home/user/slint/internal/backends/winit)`
    ... which satisfies path dependency `i-slint-backend-winit` (locked to 1.0.3) of package `i-slint-backend-selector v1.0.3 (/home/user/slint/internal/backends/selector)`
    ... which satisfies path dependency `i-slint-backend-selector` (locked to 1.0.3) of package `slint v1.0.3 (/home/user/slint/api/rs/slint)`
    ... which satisfies path dependency `slint` (locked to 1.0.3) of package `_7guis v1.0.3 (/home/user/slint/examples/7guis)`
Only one package in the dependency graph may specify the same links value. This helps ensure that only one copy of a native library is linked in the final binary. Try to adjust your dependencies so that only one package uses the links ='skia-bindings' value. For more information, see https://doc.rust-lang.org/cargo/reference/resolver.html#links.

failed to select a version for `skia-bindings` which could resolve this conflict

I'm not sure where the conflict is coming from, Cargo.toml and cargo-config.toml is still default;

# Copyright © SixtyFPS GmbH <info@slint-ui.com>
# SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-commercial

[package]
name = "mcu-board-support"
version = "1.0.3"
authors = ["Slint Developers <info@slint-ui.com>"]
edition = "2021"
license = "GPL-3.0-only OR LicenseRef-Slint-commercial"
publish = false
description = "Internal helper that includes support for different MCUs, for use in Slint examples"
repository = "https://github.com/slint-ui/slint"
homepage = "https://slint-ui.com"
links = "mcu_board_support" # just so we can pass metadata to the slint build crate

[lib]
path = "lib.rs"

[features]
pico-st7789 = ["slint/unsafe-single-threaded", "rp-pico", "embedded-hal", "cortex-m-rt", "embedded-alloc", "fugit", "cortex-m", "display-interface", "st7789", "defmt", "defmt-rtt", "shared-bus", "slint/libm", "embedded-dma", "embedded-graphics", "euclid/libm"]
stm32h735g = ["slint/unsafe-single-threaded", "embedded-hal", "cortex-m/critical-section-single-core", "cortex-m-rt","embedded-alloc", "embedded-time", "cortex-m", "stm32h7xx-hal/stm32h735", "defmt", "defmt-rtt", "embedded-display-controller", "ft5336", "panic-probe", "slint/libm", "getrandom"]
esp32-s2-kaluga-1 = ["slint/unsafe-single-threaded", "esp32s2-hal", "embedded-hal", "xtensa-lx-rt/esp32s2", "esp-alloc", "esp-println/esp32s2", "display-interface", "display-interface-spi", "st7789", "slint/libm"]
esp32-s3-box = ["slint/unsafe-single-threaded", "esp32s3-hal", "embedded-hal", "xtensa-lx-rt/esp32s3", "esp-alloc", "esp-println/esp32s3", "esp-backtrace/esp32s3", "display-interface", "display-interface-spi", "mipidsi", "embedded-graphics", "slint/libm", "tt21100"]

[dependencies]
slint = { version = "=1.0.3", path = "../../api/rs/slint", default-features = false, features = ["compat-1-0"] }
i-slint-core-macros = { version = "=1.0.3", path = "../../internal/core-macros" }

derive_more = "0.99.5"
embedded-graphics = { version = "0.7.1", optional = true }
once_cell = { version = "1.9", default-features = false, features = ["alloc", "atomic-polyfill"] }
pin-weak = { version = "1", default-features = false }
rgb = "0.8.27"
cfg-if = "1"

embedded-alloc = { version = "0.5", optional = true }
cortex-m-rt = { version = "0.7", optional = true }
cortex-m = { version = "0.7.2", optional = true }
display-interface = { version = "0.4.1", optional = true }
embedded-hal = { version = "0.2.5", optional = true }
embedded-dma = { version = "0.2.0", optional = true }
# Use a git branch that has DMA support
rp-pico = { version = "0.7.0", optional = true }
fugit = { version = "0.3.6", optional = true }
shared-bus = { version = "0.2", optional = true }
st7789 = { version = "0.7.0", optional = true }
euclid = { version = "0.22", default-features = false, optional = true }

stm32h7xx-hal = { version = "0.13.0", optional = true, features = ["log-rtt", "ltdc", "xspi"] }
getrandom = { version = "0.2", optional = true, default-features = false, features = ["custom"] }
embedded-time = { version = "0.12.0", optional = true }
embedded-display-controller = { version = "0.1.0", optional = true }
# Use upstream git version to enable use of panic-probe (released version enforced panic-semihosting)
ft5336 = { version = "0.1", git = "https://github.com/bobgates/ft5336", rev = "293730a225a68b6364857602f8fb62fd0beb8a26", optional = true }

esp32s2-hal = { version = "0.7", optional = true }
esp32s3-hal = { version = "0.7", optional = true }
xtensa-lx-rt = { version = "0.15", optional = true }
display-interface-spi = { version = "0.4", optional = true }
esp-alloc = { version = "0.2", optional = true, features = ["oom-handler"] }
esp-println = { version = "0.4.0", optional = true }
esp-backtrace = { version = "0.6.0", optional = true, features = ["panic-handler", "print-uart"] }
tt21100 = { version = "0.1", optional = true }

mipidsi = { version = "0.6.0", optional = true }

defmt-rtt = { version = "0.4.0", optional = true }
defmt = { version = "0.3.0", optional = true }
panic-probe = { version = "0.3.0", optional = true, features = ["print-defmt"] }

[build-dependencies]
cfg-if = "1.0.0"

# Copyright © SixtyFPS GmbH <info@slint-ui.com>
# SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-commercial

[target.xtensa-esp32s3-none-elf]
runner = "espflash --monitor"

[build]
rustflags = [
    "-C", "force-frame-pointers",
    "-C", "link-arg=-nostartfiles",
    "-C", "link-arg=-Wl,-Tlinkall.x",
    "-C", "target-feature=-fp",
]
target = "xtensa-esp32s3-none-elf"

[unstable]
build-std = ["core", "alloc"]

[tronical]

You might be pleased to learn that in Slint 1.2.0 we've added support for building with idf.py through the Slint ESP-IDF component.