Merge pull request #26057 from asmorkalov:as/android_16k_pages

Android builds update #26057

Fixes https://github.com/opencv/opencv/issues/26027
Should also address https://github.com/opencv/opencv/issues/26542
 
Changes:
- Switched to Android build tools 34, NDK 26d, target API level 34 (required by Google Play).
- Use flexible page size on Android by default to support Android 15+.
- Dummy stub for R and BuildConfig classes for javadoc.
- Java 17 everywhere.
- Strict ndkVersion and ABI list in release package.

Related:
- Docker: https://github.com/opencv-infrastructure/opencv-gha-dockerfile/pull/41
- Pipeline: https://github.com/opencv/ci-gha-workflow/pull/183

Related IPP issue with NDK 27+: https://github.com/opencv/opencv/issues/26072

Google documentation for 16kb pages support : https://developer.android.com/guide/practices/page-sizes?hl=en

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake

platforms/android/aar-template/OpenCV/build.gradle.template

@@ -7,6 +7,7 @@ plugins {
 android {
     namespace 'org.opencv'
     compileSdk ${COMPILE_SDK}
+    ndkVersion "${NDK_VERSION}"
 
     defaultConfig {
         minSdk ${MIN_SDK}

platforms/android/aar-template/build.gradle

@@ -1,5 +1,5 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 plugins {
-    id 'com.android.library' version '7.3.0' apply false
+    id 'com.android.library' version '8.6.0' apply false
     id 'org.jetbrains.kotlin.android' version '1.8.20' apply false
 }

platforms/android/aar-template/gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 #Mon Jul 10 11:57:38 SGT 2023
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.6.3-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.11.1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

platforms/android/build_java_shared_aar.py

@@ -47,6 +47,14 @@ def get_opencv_version(opencv_sdk_path):
         revision = re.search(r'^#define\W+CV_VERSION_REVISION\W+(\d+)$', data, re.MULTILINE).group(1)
         return "%(major)s.%(minor)s.%(revision)s" % locals()
 
+def get_ndk_version(ndk_path):
+    props_path = path.join(ndk_path, "source.properties")
+    with open(props_path, "rt") as f:
+        data = f.read()
+        version = re.search(r'Pkg\.Revision\W+=\W+(\d+\.\d+\.\d+)', data).group(1)
+        return version.strip()
+
+
 def get_compiled_aar_path(path1, path2):
     if path.exists(path1):
         return path1
@@ -70,6 +78,8 @@ def cleanup(paths_to_remove):
 
 def main(args):
     opencv_version = get_opencv_version(args.opencv_sdk_path)
+    ndk_version = get_ndk_version(args.ndk_location)
+    print("Detected ndk_version:", ndk_version)
     abis = os.listdir(path.join(args.opencv_sdk_path, "sdk/native/libs"))
     lib_name = "opencv_java" + opencv_version.split(".")[0]
     final_aar_path = FINAL_AAR_PATH_TEMPLATE.replace("<OPENCV_VERSION>", opencv_version)
@@ -90,6 +100,7 @@ def main(args):
                    "LIB_TYPE": "c++_shared",
                    "PACKAGE_NAME": MAVEN_PACKAGE_NAME,
                    "OPENCV_VERSION": opencv_version,
+                   "NDK_VERSION": ndk_version,
                    "COMPILE_SDK": args.android_compile_sdk,
                    "MIN_SDK": args.android_min_sdk,
                    "TARGET_SDK": args.android_target_sdk,
@@ -170,10 +181,10 @@ def main(args):
 if __name__ == "__main__":
     parser = argparse.ArgumentParser(description="Builds AAR with Java and shared C++ libs from OpenCV SDK")
     parser.add_argument('opencv_sdk_path')
-    parser.add_argument('--android_compile_sdk', default="31")
+    parser.add_argument('--android_compile_sdk', default="34")
     parser.add_argument('--android_min_sdk', default="21")
-    parser.add_argument('--android_target_sdk', default="31")
-    parser.add_argument('--java_version', default="1_8")
+    parser.add_argument('--android_target_sdk', default="34")
+    parser.add_argument('--java_version', default="17")
     parser.add_argument('--ndk_location', default="")
     parser.add_argument('--cmake_location', default="")
     parser.add_argument('--offline', action="store_true", help="Force Gradle use offline mode")

platforms/android/build_sdk.py

@@ -285,7 +285,10 @@ class Builder:
         cmd.append(self.opencvdir)
         execute(cmd)
         # full parallelism for C++ compilation tasks
-        execute([self.ninja_path, "opencv_modules"])
+        build_targets = ["opencv_modules"]
+        if do_install:
+            build_targets.append("opencv_tests")
+        execute([self.ninja_path, *build_targets])
         # limit parallelism for building samples (avoid huge memory consumption)
         if self.no_samples_build:
             execute([self.ninja_path, "install" if (self.debug_info or self.debug) else "install/strip"])
@@ -300,6 +303,14 @@ class Builder:
                     classpaths.append(os.path.join(dir, f))
         srcdir = os.path.join(self.resultdest, 'sdk', 'java', 'src')
         dstdir = self.docdest
+        # HACK: create stubs for auto-generated files to satisfy imports
+        with open(os.path.join(srcdir, 'org', 'opencv', 'BuildConfig.java'), 'wt') as fs:
+            fs.write("package org.opencv;\n public class BuildConfig {\n}")
+            fs.close()
+        with open(os.path.join(srcdir, 'org', 'opencv', 'R.java'), 'wt') as fs:
+            fs.write("package org.opencv;\n public class R {\n}")
+            fs.close()
+
         # synchronize with modules/java/jar/build.xml.in
         shutil.copy2(os.path.join(SCRIPT_DIR, '../../doc/mymath.js'), dstdir)
         cmd = [
@@ -327,9 +338,12 @@ class Builder:
             '-bottom', 'Generated on %s / OpenCV %s' % (time.strftime("%Y-%m-%d %H:%M:%S"), self.opencv_version),
             "-d", dstdir,
             "-classpath", ":".join(classpaths),
-            '-subpackages', 'org.opencv',
+            '-subpackages', 'org.opencv'
         ]
         execute(cmd)
+        # HACK: remove temporary files needed to satisfy javadoc imports
+        os.remove(os.path.join(srcdir, 'org', 'opencv', 'BuildConfig.java'))
+        os.remove(os.path.join(srcdir, 'org', 'opencv', 'R.java'))
 
     def gather_results(self):
         # Copy all files

platforms/android/build_static_aar.py

@@ -7,7 +7,7 @@ import os
 import shutil
 import subprocess
 
-from build_java_shared_aar import cleanup, fill_template, get_compiled_aar_path, get_opencv_version
+from build_java_shared_aar import cleanup, fill_template, get_compiled_aar_path, get_opencv_version, get_ndk_version
 
 
 ANDROID_PROJECT_TEMPLATE_DIR = path.join(path.dirname(__file__), "aar-template")
@@ -103,6 +103,8 @@ def convert_deps_list_to_prefab(linked_libs, opencv_libs, external_libs):
 
 def main(args):
     opencv_version = get_opencv_version(args.opencv_sdk_path)
+    ndk_version = get_ndk_version(args.ndk_location)
+    print("Detected ndk_version:", ndk_version)
     abis = os.listdir(path.join(args.opencv_sdk_path, "sdk/native/libs"))
     final_aar_path = FINAL_AAR_PATH_TEMPLATE.replace("<OPENCV_VERSION>", opencv_version)
     sdk_dir = args.opencv_sdk_path
@@ -121,6 +123,7 @@ def main(args):
                    "LIB_TYPE": "c++_static",
                    "PACKAGE_NAME": MAVEN_PACKAGE_NAME,
                    "OPENCV_VERSION": opencv_version,
+                   "NDK_VERSION": ndk_version,
                    "COMPILE_SDK": args.android_compile_sdk,
                    "MIN_SDK": args.android_min_sdk,
                    "TARGET_SDK": args.android_target_sdk,
@@ -243,9 +246,9 @@ def main(args):
 if __name__ == "__main__":
     parser = argparse.ArgumentParser(description="Builds AAR with static C++ libs from OpenCV SDK")
     parser.add_argument('opencv_sdk_path')
-    parser.add_argument('--android_compile_sdk', default="31")
+    parser.add_argument('--android_compile_sdk', default="34")
     parser.add_argument('--android_min_sdk', default="21")
-    parser.add_argument('--android_target_sdk', default="31")
+    parser.add_argument('--android_target_sdk', default="34")
     parser.add_argument('--java_version', default="1_8")
     parser.add_argument('--ndk_location', default="")
     parser.add_argument('--cmake_location', default="")

platforms/android/default.config.py

@@ -0,0 +1,6 @@
+ABIs = [
+    ABI("2", "armeabi-v7a", None, 21, cmake_vars=dict(ANDROID_ABI='armeabi-v7a with NEON')),
+    ABI("3", "arm64-v8a",   None, 21, cmake_vars=dict(ANDROID_SUPPORT_FLEXIBLE_PAGE_SIZES='ON')),
+    ABI("5", "x86_64",      None, 21, cmake_vars=dict(ANDROID_SUPPORT_FLEXIBLE_PAGE_SIZES='ON')),
+    ABI("4", "x86",         None, 21),
+]