New module to find absolute icon paths without the help of qt. Thanks for nothing, qt

engine/findicons.py

@@ -0,0 +1,142 @@
+#! /usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Copyright 2020, Nils Hilbricht, Germany ( https://www.hilbricht.net )
+
+This file is part of the Laborejo Software Suite ( https://www.laborejo.org ),
+
+This 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 <http://www.gnu.org/licenses/>.
+"""
+
+import logging; logger = logging.getLogger(__name__); logger.info("import")
+
+from os import getenv
+import os
+import pathlib
+import re
+
+"""
+https://specifications.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html
+https://specifications.freedesktop.org/icon-theme-spec/icon-theme-spec-latest.html#icon_lookup
+
+$HOME/.icons (for backwards compatibility)
+$XDG_DATA_DIRS/icons
+/usr/share/pixmaps
+"""
+
+SEARCH_DIRECTORIES = [pathlib.Path(pathlib.Path.home(), ".icons")]
+
+XDG_DATA_DIRS = getenv("XDG_DATA_DIRS")  #colon : separated, most likely empty
+if XDG_DATA_DIRS:
+    SEARCH_DIRECTORIES += [pathlib.Path(p, "icons") for p in XDG_DATA_DIRS.split(":")]
+else:
+    #If $XDG_DATA_DIRS is either not set or empty, a value equal to /usr/local/share/:/usr/share/ should be used.
+    SEARCH_DIRECTORIES += [pathlib.Path(p, "icons") for p in "/usr/local/share/:/usr/share/".split(":")]
+
+SEARCH_DIRECTORIES.append(pathlib.Path("/usr/share/pixmaps"))
+
+
+def run_fast_scandir(dir, ext):
+    """
+    https://stackoverflow.com/questions/18394147/recursive-sub-folder-search-and-return-files-in-a-list-python
+    """
+    subfolders, files = [], []
+
+    try:
+        for f in os.scandir(dir):
+            if f.is_dir():
+                subfolders.append(f.path)
+            if f.is_file():
+                if os.path.splitext(f.name)[1].lower() in ext:
+                    files.append(f.path)
+
+        for dir in list(subfolders):
+            sf, f = run_fast_scandir(dir, ext)
+            subfolders.extend(sf)
+            files.extend(f)
+
+    except PermissionError:
+        pass
+
+    except FileNotFoundError:
+        pass
+
+    return subfolders, files
+
+
+def _buildCache()->set:
+    result = []
+    for basePath in SEARCH_DIRECTORIES:
+        forget, files = run_fast_scandir(basePath, [".png", ".xpm", ".svg"])
+        result += files
+
+    #Convert str to real paths
+    result = [pathlib.Path(r) for r in result if pathlib.Path(r).is_file()]
+
+    return set(result)
+
+_cache = _buildCache()
+
+
+rePattern =  re.compile("\d+x\d+") #we don't put .* around this because we are searching for the subpattern
+
+def findIconPath(executableName:str)->list:
+    """Return order is: svg first, then highest resolution first, then the rest unordered.
+    so you can use result[0] for the best variant.
+    It is not guaranteed that [1], or even [0] exists.
+    This is not a sorted list, these extra variants are just added to the front of the list again"""
+
+    executableName = executableName.lower()
+
+    svg = None
+    bestr = 0 #resolution
+    best = None
+
+    result = []
+    for f in _cache:
+        if f.stem == executableName:
+            if f.suffix == ".svg":
+                svg = f
+            else:
+                match = re.search(rePattern, str(f)) #find resolution dir like /48x48/
+                if match:
+                    resolutionAsNumber = int(match.group().split("x")[0])
+                    if resolutionAsNumber > bestr: #new best one
+                        bestr = resolutionAsNumber
+                        best = f
+            result.append(f)
+
+    if best:
+        result.insert(0, best)
+    if svg:
+        result.insert(0, svg)
+
+    return result
+
+if __name__ == "__main__":
+    """Example that tries to find a few icons"""
+
+    print("Search paths:")
+    print(SEARCH_DIRECTORIES)
+    print()
+
+    for exe in ("ZynAddSubFx", "patroneo", "jack_mixer", "carla", "ardour6", "synthv1"):
+        r = findIconPath(exe)
+        if r:
+            print (f"{exe} Best resolution: {r[0]}")
+        else:
+            print (f"{exe}: No icon found ")
+
+
+