Merge: app.nit: Intro the `app_files` annotation, and use it in calculator

Intro `app_files`, an annotation to specify where to find more Android and iOS specific files. This effectively associates resources to a specific Nit module. It can be used to have different icons per branding, or to package graphical assets with a module from the lib.

It is used in the calculator to assign a different icon to the scientific calculator variant.

Pull-Request: #2228
Reviewed-by: Lucas Bajolet <r4pass@hotmail.com>
Reviewed-by: Romain Chanoir <romain.chanoir@viacesi.fr>

diff --combined src/platform/android.nit
index 1e89a84,50a9d09..adb9543
--- 1/src/platform/android.nit
--- 2/src/platform/android.nit
+++ b/src/platform/android.nit
@@@ -104,12 -104,6 +104,12 @@@ class AndroidToolchai
                dir = compile_dir
                if not dir.file_exists then dir.mkdir
  
 +              # Insert an importation of the generated R class to all Java files from the FFI
 +              for mod in compiler.mainmodule.in_importation.greaters do
 +                      var java_ffi_file = mod.java_file
 +                      if java_ffi_file != null then java_ffi_file.add "import {app_package}.R;"
 +              end
 +
                # compile normal C files
                super
  
@@@ -118,7 -112,6 +118,6 @@@
                        if f isa ExternCFile then cfiles.add(f.filename.basename)
                end
  
-               # Is there an icon?
                var project_root = "."
                var mpackage = compiler.mainmodule.first_real_mmodule.mpackage
                if mpackage != null then
@@@ -131,6 -124,35 +130,35 @@@
                        end
                end
  
+               # Set the default pretty application name
+ """<?xml version="1.0" encoding="utf-8"?>
+ <resources>
+     <string name="app_name">{{{app_name}}}</string>
+ </resources>""".write_to_file "{android_project_root}/res/values/strings.xml"
+ 
+               # Copy assets, resources and libs where expected by the SDK
+ 
+               ## Collect path to all possible folder where we can find the `android` folder
+               var app_files = [project_root]
+               app_files.add_all project.files
+ 
+               for path in app_files do
+                       # Copy the assets folder
+                       var assets_dir = path / "assets"
+                       if assets_dir.file_exists then
+                               assets_dir = assets_dir.realpath
+                               toolcontext.exec_and_check(["cp", "-r", assets_dir, android_project_root], "Android project error")
+                       end
+ 
+                       # Copy the whole `android` folder
+                       var android_dir = path / "android"
+                       if android_dir.file_exists then
+                               android_dir = android_dir.realpath
+                               toolcontext.exec_and_check(["cp", "-r", android_dir, root_compile_dir], "Android project error")
+                       end
+               end
+ 
+               # Is there an icon?
                var resolutions = ["ldpi", "mdpi", "hdpi", "xhdpi", "xxhdpi", "xxxhdpi"]
                var icon_available = false
                for res in resolutions do
@@@ -246,7 -268,7 +274,7 @@@ $(call import-module,android/native_app
  
                ### Link to png sources
                # libpng is not available on Android NDK
 -              # FIXME make obtionnal when we have alternatives to mnit
 +              # FIXME make optional when we have alternatives to mnit
                var nit_dir = toolcontext.nit_dir
                var share_dir =  nit_dir/"share/"
                if not share_dir.file_exists then
@@@ -270,40 -292,6 +298,6 @@@
  
                toolcontext.exec_and_check(["ln", "-s", "{share_dir}/libgc/arm/include/gc/",
                        "{compile_dir}/gc"], "Android project error")
- 
-               # Copy assets, resources and libs where expected by the SDK
- 
-               # Link to assets (for mnit and others)
-               var assets_dir = project_root / "assets"
-               if assets_dir.file_exists then
-                       assets_dir = assets_dir.realpath
-                       var target_assets_dir = "{android_project_root}/assets"
-                       if not target_assets_dir.file_exists then
-                               toolcontext.exec_and_check(["ln", "-s", assets_dir, target_assets_dir], "Android project error")
-                       end
-               end
- 
-               # Copy the res folder
-               var res_dir = project_root / "android/res"
-               if res_dir.file_exists then
-                       # copy the res folder to the compile dir
-                       res_dir = res_dir.realpath
-                       toolcontext.exec_and_check(["cp", "-R", res_dir, android_project_root], "Android project error")
-               end
- 
-               if not res_dir.file_exists or not "{res_dir}/values/strings.xml".file_exists then
-                       # Create our own custom `res/values/string.xml` with the App name
- """<?xml version="1.0" encoding="utf-8"?>
- <resources>
-     <string name="app_name">{{{app_name}}}</string>
- </resources>""".write_to_file "{android_project_root}/res/values/strings.xml"
-               end
- 
-               # Copy the libs folder
-               var libs_dir = project_root / "android/libs"
-               if libs_dir.file_exists then
-                       toolcontext.exec_and_check(["cp", "-r", libs_dir, android_project_root], "Android project error")
-               end
        end
  
        redef fun write_makefile(compile_dir, cfiles)