[gimp] Add meson_install_subdir script

[Jehan <jehanp src gnome org>]

commit db8922738fe3a2e252825f03232353dc7f28a173
Author: Félix Piédallu <felix piedallu me>
Date:   Fri Aug 30 12:04:28 2019 +0200

    Add meson_install_subdir script

 meson.build                   | 16 ++++++++
 tools/meson_install_subdir.py | 94 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 110 insertions(+)
---
diff --git a/meson.build b/meson.build
index c94244807b..3a1d3fd454 100644
--- a/meson.build
+++ b/meson.build
@@ -1012,6 +1012,7 @@ generate_changelog  = find_program('tools'/'generate_changelog.sh')
 generate_news       = find_program('tools'/'generate-news')
 gimppath2svg        = find_program('tools'/'gimppath2svg.py')
 module_dependencies = find_program('tools'/'module-dependencies.py')
+meson_install_subdir= find_program('tools'/'meson_install_subdir.py')
 
 gimp_mkenums        = find_program('tools'/'gimp-mkenums')
 gimp_mkenums_custom_target_commonargs = [
@@ -1548,6 +1549,21 @@ pkgconfig.generate(libgimpui,
 
 
 
+################################################################################
+# Subdir installations
+
+foreach dir : [
+    { 'dir': 'libgimp',   'deps': libgimp},
+    { 'dir': 'plug-ins', },
+  ]
+  run_target('install-' + dir.get('dir'),
+    command: [
+      meson_install_subdir, '-v', dir.get('dir')
+    ],
+    depends: dir.get('deps', [])
+  )
+endforeach
+
 ################################################################################
 
 final_message = [
diff --git a/tools/meson_install_subdir.py b/tools/meson_install_subdir.py
new file mode 100755
index 0000000000..2118309f82
--- /dev/null
+++ b/tools/meson_install_subdir.py
@@ -0,0 +1,94 @@
+#!/usr/bin/env python3
+
+import sys, os
+from pathlib import Path
+import argparse
+
+import json
+
+import shutil
+
+
+class Singleton(type):
+    _instances = {}
+    def __call__(cls, *args, **kwargs):
+        if cls not in cls._instances:
+            cls._instances[cls] = super(Singleton, cls).__call__(*args, **kwargs)
+        return cls._instances[cls]
+
+def copytree(src, dst, symlinks=False, ignore=None):
+    for item in os.listdir(src):
+        s = os.path.join(src, item)
+        d = os.path.join(dst, item)
+        if os.path.isdir(s):
+            shutil.copytree(s, d, symlinks, ignore)
+        else:
+            shutil.copy2(s, d)
+
+class MesonStatus(metaclass = Singleton):
+    def __init__(self):
+        self.get_build_dir()
+        self.get_meson_info()
+        self.get_meson_installed()
+
+    def get_build_dir(self):
+        self.buildroot = None
+
+        cwd = Path(os.getcwd())
+
+        if (cwd / 'meson-info').exists():
+            self.buildroot = cwd
+
+        with cwd / '_build' as _build:
+            if (_build / 'meson-info').exists():
+                self.buildroot = _build
+
+        if self.buildroot is None:
+            print('Error: build directory was not detected. Are you in it ?')
+
+    def get_meson_info(self):
+        with open(self.buildroot / 'meson-info' / 'meson-info.json') as file:
+            self.meson_info = json.load(file)
+        self.sourceroot = Path(self.meson_info['directories']['source'])
+
+    def get_meson_installed(self):
+        info = self.meson_info['directories']['info']
+        inst = self.meson_info['introspection']['information']['installed']['file']
+
+        with open(Path(info) / inst) as file:
+            self.installed_files = json.load(file)
+
+
+def get_files_of_part(part_name):
+    files_of_part = {}
+    sourcedir = str(MesonStatus().sourceroot / part_name)
+    builddir  = str(MesonStatus().buildroot  / part_name)
+    for file, target in MesonStatus().installed_files.items():
+        if file.startswith(sourcedir + '/') or file.startswith(builddir + '/'):
+            files_of_part[file] = target
+
+    return files_of_part
+
+def install_files(files, verbose):
+    for file in sorted(files.keys()):
+        target = files[file]
+        if verbose: print(file + '  →  ' + target, end='\n')
+
+        if os.path.isdir(file):
+            copytree(file, target)
+        if os.path.isfile(file):
+            shutil.copy(file, target)
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser()
+    parser.add_argument('subdirs', nargs='+')
+    parser.add_argument('--verbose', '-v', action='store_true')
+    args = parser.parse_args()
+
+    verbose = args.verbose
+
+    for subdir in args.subdirs:
+        files = get_files_of_part(subdir)
+        if len(files) == 0:
+            print('Error: subdir %s does not contain any installable file' % subdir)
+        install_files(files, verbose)