Configure Meson as the build tool

The meson.build file is partially based on the gtk-rust-template present
at https://gitlab.gnome.org/World/Rust/gtk-rust-template, although
because I am going step by step, I still haven't enabled most of the
data/ dependencies like blueprint-compiler, glib-compile-resources or
glib-compile-schemas. They will be done in separate commits.

In this commit, therefore:

* The README file is updated to reflect how to use Meson to build the
  application. It is clunky, but I bet that it will save in the long
  term.

* A meson.build file is configured to use cargo in order to compile the
  source code. Apparently Meson likes to vendor dependencies, so
  triggering `ninja build` will cause dependencies to be re-downloaded
  and compiled, even if `cargo build` was run before.

* Some support scripts like the dist-vendor.sh script or the git hook
  that prevents committing code if the `cargo fmt` command does not
  approve the code.

README.md

@@ -39,8 +39,10 @@ On future versions, more capabilities will be added:
 
 ## How to build
 
-> These instructions will change very soon once Meson is introduced. Don't get
-> very used to them because they will change.
+Note that compiling via `cargo build` and `cargo run` is not supported anymore,
+since more build steps are required in order to compile the application
+(translate .blp files into .ui files...). While it may work if you run the
+commands on your own, it won't be pretty.
 
 Currently, to build the application you'll have to make sure that the required
 libraries are installed on your system.
@@ -49,18 +51,53 @@ libraries are installed on your system.
 * gtk >= 4.14
 * gtksourceview >= 5.12
 
-To compile the application, run `cargo build`.
+### Meson
 
-To optimize the application, run `cargo build --release`.
+Make sure that you have Meson in your system. For instance,
 
-The binary will be generated at the proper subdirectory inside `target`, or you
-can run it using `cargo run`.
+```sh
+sudo apt install meson
+sudo dnf install meson
+sudo pacman -S meson
+```
 
-Also, if you want to modify the Blueprint files, you are going to need
-**blueprint-compiler >= 0.10**. You might be able to get it from your package
-manager or you can [build it from sources][bp]. Invoke the compiler and make
-sure you update the .ui files from the .blp source files before compiling the
-application.
+Then use the following commands to build and install the application
+
+```sh
+meson setup build
+ninja -C build
+ninja -C build install
+```
+
+To avoid installing system-wide the application, you can use a prefix:
+
+```sh
+meson setup build --prefix=~/.local
+ninja -C build
+ninja -C build install
+```
+
+During development mode, you may also prefer to install into the development
+directory. Because the application may depend on files generated by Meson that
+are installed into specific locations, this may be a required step if you
+suddenly cannot run the application due to missing schemas or resources.
+
+```sh
+meson setup build --prefix=install
+ninja -C build
+ninja -C build install
+install/bin/cartero
+```
+
+**If you plan on contributing to the project**, use the development profile.
+
+```sh
+meson setup build -Dprofile=development
+```
+
+It will also configure a Git hook so that the source code is checked prior to
+authoring a Git commit. The hook runs `cargo fmt` to assert that the code is
+formatted. Read `hooks/pre-commit.hook` to inspect what the script does.
 
 ## Contributing
 

build-aux/dist-vendor.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+# Since Meson invokes this script as
+# "/bin/sh .../dist-vendor.sh DIST SOURCE_ROOT" we can't rely on bash features
+set -eu
+export DIST="$1"
+export SOURCE_ROOT="$2"
+
+cd "$SOURCE_ROOT"
+mkdir "$DIST"/.cargo
+cargo vendor > "$DIST/.cargo/config"
+# Don't combine the previous and this line with a pipe because we can't catch
+# errors with "set -o pipefail"
+sed -i 's/^directory = ".*"/directory = "vendor"/g' "$DIST/.cargo/config"
+# Move vendor into dist tarball directory
+mv vendor "$DIST"

hooks/pre-commit.hook

@@ -0,0 +1,57 @@
+#!/bin/sh
+# Source: https://gitlab.gnome.org/GNOME/fractal/blob/master/hooks/pre-commit.hook
+
+install_rustfmt() {
+    if ! which rustup >/dev/null 2>&1; then
+        curl https://sh.rustup.rs -sSf  | sh -s -- -y
+        export PATH=$PATH:$HOME/.cargo/bin
+        if ! which rustup >/dev/null 2>&1; then
+            echo "Failed to install rustup. Performing the commit without style checking."
+            exit 0
+        fi
+    fi
+
+    if ! rustup component list|grep rustfmt >/dev/null 2>&1; then
+        echo "Installing rustfmt…"
+        rustup component add rustfmt
+    fi
+}
+
+if ! which cargo >/dev/null 2>&1 || ! cargo fmt --help >/dev/null 2>&1; then
+    echo "Unable to check the project’s code style, because rustfmt could not be run."
+
+    if [ ! -t 1 ]; then
+        # No input is possible
+        echo "Performing commit."
+        exit 0
+    fi
+
+    echo ""
+    echo "y: Install rustfmt via rustup"
+    echo "n: Don't install rustfmt and perform the commit"
+    echo "Q: Don't install rustfmt and abort the commit"
+
+    echo ""
+    while true
+    do
+        printf "%s" "Install rustfmt via rustup? [y/n/Q]: "; read yn < /dev/tty
+        case $yn in
+            [Yy]* ) install_rustfmt; break;;
+            [Nn]* ) echo "Performing commit."; exit 0;;
+            [Qq]* | "" ) echo "Aborting commit."; exit 1 >/dev/null 2>&1;;
+            * ) echo "Invalid input";;
+        esac
+    done
+
+fi
+
+echo "--Checking style--"
+cargo fmt --all -- --check
+if test $? != 0; then
+    echo "--Checking style fail--"
+    echo "Please fix the above issues, either manually or by running: cargo fmt --all"
+
+    exit 1
+else
+    echo "--Checking style pass--"
+fi

meson.build

@@ -0,0 +1,65 @@
+# Copyright 2024 the Cartero authors
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+project(
+  'cartero',
+  'rust',
+  version: '0.1',
+  meson_version: '>= 0.59',
+  license: 'GPL-3.0-or-later',
+)
+
+base_id = 'es.danirod.Cartero'
+
+dependency('glib-2.0', version: '>= 2.80')
+dependency('gtk4', version: '>= 4.14')
+dependency('gtksourceview-5', version: '>= 5.12')
+
+cargo = find_program('cargo', required: true)
+
+version = meson.project_version()
+prefix = get_option('prefix')
+bindir = prefix / get_option('bindir')
+
+if get_option('profile') == 'development'
+  profile = 'Devel'
+  vcs_tag = run_command('git', 'rev-parse', '--short', 'HEAD', check: false).stdout().strip()
+  if vcs_tag == ''
+    version_suffix = '-devel'
+  else
+    version_suffix = '-@0@'.format(vcs_tag)
+  endif
+  application_id = '@0@.@1@'.format(base_id, profile)
+else
+  profile = ''
+  version_suffix = ''
+  application_id = base_id
+endif
+
+meson.add_dist_script(
+  'build-aux/dist-vendor.sh',
+  meson.project_build_root() / 'meson-dist' / meson.project_name() + '-' + version,
+  meson.project_source_root()
+)
+
+if get_option('profile') == 'development'
+  # Setup pre-commit hook for ensuring coding style is always consistent
+  message('Setting up git pre-commit hook..')
+  run_command('cp', '-f', 'hooks/pre-commit.hook', '.git/hooks/pre-commit', check: false)
+endif
+
+subdir('src')

meson_options.txt

@@ -0,0 +1,10 @@
+option(
+  'profile',
+  type: 'combo',
+  choices: [
+    'default',
+    'development'
+  ],
+  value: 'default',
+  description: 'The build profile for Cartero. One of "default" or "development".'
+)

src/meson.build

@@ -0,0 +1,48 @@
+# Copyright 2024 the Cartero authors
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+cargo_options = [ '--manifest-path', meson.project_source_root() / 'Cargo.toml' ]
+cargo_options += [ '--target-dir', meson.project_build_root() / 'src' ]
+
+if get_option('profile') == 'default'
+  cargo_options += [ '--release' ]
+  rust_target = 'release'
+  message('Building in release mode')
+else
+  rust_target = 'debug'
+  message('Building in debug mode')
+endif
+
+cargo_env = [ 'CARGO_HOME=' + meson.project_build_root() / 'cargo-home' ]
+
+cargo_build = custom_target(
+  'cargo-build',
+  build_by_default: true,
+  build_always_stale: true,
+  output: meson.project_name(),
+  console: true,
+  install: true,
+  install_dir: bindir,
+  command: [
+    'env',
+    cargo_env,
+    cargo, 'build',
+    cargo_options,
+    '&&',
+    'cp', 'src' / rust_target / meson.project_name(), '@OUTPUT@',
+  ]
+)