android: gradle-based package and samples

- drop hello-android sample

modules/java/CMakeLists.txt

@@ -3,8 +3,8 @@ if(OPENCV_INITIAL_PASS)
   add_subdirectory(generator)
 endif()
 
-if(APPLE_FRAMEWORK OR WINRT OR NOT PYTHON_DEFAULT_AVAILABLE OR NOT ANT_EXECUTABLE
-    OR NOT (JNI_FOUND OR (ANDROID AND ANDROID_NATIVE_API_LEVEL GREATER 7))
+if(APPLE_FRAMEWORK OR WINRT OR NOT PYTHON_DEFAULT_AVAILABLE OR NOT (ANT_EXECUTABLE OR ANDROID_PROJECTS_BUILD_TYPE STREQUAL "GRADLE")
+    OR NOT (JNI_FOUND OR (ANDROID AND (NOT DEFINED ANDROID_NATIVE_API_LEVEL OR ANDROID_NATIVE_API_LEVEL GREATER 7)))
     OR BUILD_opencv_world
     )
   ocv_module_disable(java)
@@ -55,7 +55,7 @@ macro(copy_common_tests _src_location _dst_location _deps)
 endmacro()
 
 
-add_subdirectory(jni)  # generates ${the_module} target (${the_module}_jni doesn't work properly with Android samples)
+add_subdirectory(jni)  # generates ${the_module} target (${the_module}_jni doesn't work properly with Android non-gradle samples)
 if(ANDROID)
   add_subdirectory(android_sdk)  # generates ${the_module}_android target
 else()

modules/java/android_sdk/CMakeLists.txt

@@ -1,12 +1,11 @@
-if(NOT ANDROID_EXECUTABLE)
-  message(WARNING "'android' tool required to build Android SDK")
-  return()
-endif()
-ocv_assert(ANDROID_TOOLS_Pkg_Revision GREATER 13)
 
 project(${the_module}_android)
 
-set(OPENCV_JAVA_DIR "${OpenCV_BINARY_DIR}/android_sdk" CACHE INTERNAL "")
+if(ANDROID_EXECUTABLE)
+  set(OPENCV_JAVA_DIR "${OpenCV_BINARY_DIR}/android_sdk" CACHE INTERNAL "")
+else()  # gradle
+  set(OPENCV_JAVA_DIR "${ANDROID_BUILD_BASE_DIR}/opencv" CACHE INTERNAL "")
+endif()
 set(OPENCV_ANDROID_LIB_DIR "${OPENCV_JAVA_DIR}" CACHE INTERNAL "")  # for OpenCV samples
 
 file(REMOVE_RECURSE "${OPENCV_JAVA_DIR}")
@@ -15,6 +14,11 @@ set(java_src_dir "${OPENCV_JAVA_DIR}/src")
 file(MAKE_DIRECTORY "${java_src_dir}")
 
 ocv_copyfiles_append_dir(JAVA_SRC_COPY "${OPENCV_JAVA_BINDINGS_DIR}/gen/java" "${java_src_dir}")
+
+if(ANDROID_EXECUTABLE)
+
+ocv_assert(ANDROID_TOOLS_Pkg_Revision GREATER 13)
+
 ocv_copyfiles_append_dir(JAVA_SRC_COPY "${OPENCV_JAVA_BINDINGS_DIR}/gen/android/java" "${java_src_dir}")
 
 # calc default SDK Target
@@ -90,5 +94,57 @@ FILE(MAKE_DIRECTORY \"\$ENV{DESTDIR}\${CMAKE_INSTALL_PREFIX}/${JAVA_INSTALL_ROOT
 FILE(MAKE_DIRECTORY \"\$ENV{DESTDIR}\${CMAKE_INSTALL_PREFIX}/${JAVA_INSTALL_ROOT}/res\")
 " COMPONENT java)
 
+ocv_update(ANDROID_COMPILE_SDK_VERSION "27")
+ocv_update(ANDROID_MIN_SDK_VERSION "14")
+ocv_update(ANDROID_TARGET_SDK_VERSION "21")
 configure_file("${CMAKE_CURRENT_SOURCE_DIR}/build.gradle.in" "${CMAKE_CURRENT_BINARY_DIR}/build.gradle" @ONLY)
 install(FILES "${CMAKE_CURRENT_BINARY_DIR}/build.gradle" DESTINATION ${JAVA_INSTALL_ROOT}/.. COMPONENT java)
+
+
+else()  # gradle build
+#
+# Android Gradle-based project
+#
+
+#TODO: INSTALL ONLY
+ocv_copyfiles_append_dir(JAVA_SRC_COPY "${OPENCV_JAVA_BINDINGS_DIR}/gen/android/java" "${java_src_dir}")
+ocv_copyfiles_append_dir(JAVA_SRC_COPY "${OPENCV_JAVA_BINDINGS_DIR}/gen/android-21/java" "${java_src_dir}")
+
+# copy boilerplate
+set(__base_dir "${CMAKE_CURRENT_SOURCE_DIR}/android_gradle_lib/")
+file(GLOB_RECURSE seed_project_files_rel RELATIVE "${__base_dir}/" "${__base_dir}/*")
+list(REMOVE_ITEM seed_project_files_rel "${ANDROID_MANIFEST_FILE}")
+foreach(file ${seed_project_files_rel})
+  configure_file("${__base_dir}/${file}" "${OPENCV_JAVA_DIR}/${file}" @ONLY)
+  list(APPEND depends "${__base_dir}/${file}")
+  get_filename_component(install_subdir "${file}" PATH)
+  install(FILES "${OPENCV_JAVA_DIR}/${file}" DESTINATION "${JAVA_INSTALL_ROOT}/${install_subdir}" COMPONENT java)
+endforeach()
+
+list(APPEND depends gen_opencv_java_source "${OPENCV_DEPHELPER}/gen_opencv_java_source")
+ocv_copyfiles_add_target(${the_module}_android_source_copy JAVA_SRC_COPY "Copy Java(Andoid SDK) source files" ${depends})
+file(REMOVE "${OPENCV_DEPHELPER}/${the_module}_android_source_copy")  # force rebuild after CMake run
+
+set(depends ${the_module}_android_source_copy "${OPENCV_DEPHELPER}/${the_module}_android_source_copy")
+
+# build jar
+set(AAR_FILE "${OPENCV_JAVA_DIR}/build/outputs/aar/opencv-release.aar")
+ocv_update(OPENCV_GRADLE_VERBOSE_OPTIONS "-i")
+add_custom_command(
+    OUTPUT "${AAR_FILE}" "${OPENCV_DEPHELPER}/${the_module}_android"
+    COMMAND ./gradlew ${OPENCV_GRADLE_VERBOSE_OPTIONS} "opencv:assemble"
+    COMMAND ${CMAKE_COMMAND} -E touch "${OPENCV_DEPHELPER}/${the_module}_android"
+    WORKING_DIRECTORY "${ANDROID_BUILD_BASE_DIR}"
+    DEPENDS ${depends} ${the_module}
+    COMMENT "Building OpenCV Android library project"
+)
+file(REMOVE "${OPENCV_DEPHELPER}/${the_module}_android")  # force rebuild after CMake run
+
+add_custom_target(${the_module}_android ALL DEPENDS "${OPENCV_DEPHELPER}/${the_module}_android" SOURCES "${__base_dir}/${ANDROID_MANIFEST_FILE}")
+
+configure_file("${CMAKE_CURRENT_SOURCE_DIR}/build.gradle.in" "${ANDROID_TMP_INSTALL_BASE_DIR}/opencv/build.gradle" @ONLY)
+install(FILES "${ANDROID_TMP_INSTALL_BASE_DIR}/opencv/build.gradle" DESTINATION ${JAVA_INSTALL_ROOT}/.. COMPONENT java)
+
+install(DIRECTORY "${java_src_dir}" DESTINATION "${JAVA_INSTALL_ROOT}" COMPONENT java)
+
+endif()  # gradle build

modules/java/android_sdk/android_gradle_lib/AndroidManifest.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+      package="org.opencv"
+      android:versionCode="@OPENCV_VERSION_MAJOR@@OPENCV_VERSION_MINOR@@OPENCV_VERSION_PATCH@0"
+      android:versionName="@OPENCV_VERSION@">
+</manifest>

modules/java/android_sdk/android_gradle_lib/build.gradle

@@ -0,0 +1,35 @@
+apply plugin: 'com.android.library'
+
+android {
+    compileSdkVersion @ANDROID_COMPILE_SDK_VERSION@
+    //buildToolsVersion "x.y.z" // not needed since com.android.tools.build:gradle:3.0.0
+
+    defaultConfig {
+        minSdkVersion @ANDROID_MIN_SDK_VERSION@
+        targetSdkVersion @ANDROID_TARGET_SDK_VERSION@
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
+        }
+    }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_6
+        targetCompatibility JavaVersion.VERSION_1_6
+    }
+
+    sourceSets {
+        main {
+            jniLibs.srcDirs = ['../../jni']
+            java.srcDirs = ['src']  // TODO Use original files instead of copied into build directory
+            aidl.srcDirs = ['src']
+            res.srcDirs = ['@OpenCV_SOURCE_DIR@/modules/java/android_sdk/android_gradle_lib/res']
+            manifest.srcFile 'AndroidManifest.xml'
+        }
+    }
+}
+
+dependencies {
+}

modules/java/android_sdk/android_gradle_lib/res/values/attrs.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <declare-styleable name = "CameraBridgeViewBase" >
+       <attr name="show_fps" format="boolean"/>
+       <attr name="camera_id" format="integer" >
+          <enum name="any" value="-1" />
+          <enum name="back" value="99" />
+          <enum name="front" value="98" />
+       </attr>
+    </declare-styleable>
+</resources>

modules/java/android_sdk/build.gradle.in

@@ -81,9 +81,9 @@
 //   splits {
 //       abi {
 //           enable true
+//           universalApk false
 //           reset()
 //           include 'armeabi-v7a' // , 'x86', 'x86_64', 'arm64-v8a'
-//           universalApk false
 //       }
 //   }
 //
@@ -93,12 +93,12 @@ apply plugin: 'com.android.library'
 println "OpenCV: " + project.buildscript.sourceFile
 
 android {
-    compileSdkVersion 27
-    //buildToolsVersion "27.0.3" // not needed since com.android.tools.build:gradle:3.0.0
+    compileSdkVersion @ANDROID_COMPILE_SDK_VERSION@
+    //buildToolsVersion "x.y.z" // not needed since com.android.tools.build:gradle:3.0.0
 
     defaultConfig {
-        minSdkVersion 14
-        targetSdkVersion 21
+        minSdkVersion @ANDROID_MIN_SDK_VERSION@
+        targetSdkVersion @ANDROID_TARGET_SDK_VERSION@
     }
 
     buildTypes {

modules/java/jni/CMakeLists.txt

@@ -13,6 +13,12 @@ foreach(m ${OPENCV_MODULES_BUILD})
   endif()
 endforeach()
 
+if(ANDROID)
+  ocv_update(JNI_OUTPUT_PATH  "${OpenCV_BINARY_DIR}/jni/${ANDROID_NDK_ABI_NAME}")
+else()
+  ocv_update(JNI_OUTPUT_PATH  "${LIBRARY_OUTPUT_PATH}")
+endif()
+
 set(__type MODULE)
 if(BUILD_FAT_JAVA_LIB)
   set(__type SHARED) # samples link to libopencv_java
@@ -60,7 +66,7 @@ endif()
 set_target_properties(${the_module} PROPERTIES
     OUTPUT_NAME "${the_module}${OPENCV_JAVA_LIB_NAME_SUFFIX}"
     ARCHIVE_OUTPUT_DIRECTORY ${LIBRARY_OUTPUT_PATH}
-    LIBRARY_OUTPUT_DIRECTORY ${LIBRARY_OUTPUT_PATH}
+    LIBRARY_OUTPUT_DIRECTORY ${JNI_OUTPUT_PATH}
     RUNTIME_OUTPUT_DIRECTORY ${EXECUTABLE_OUTPUT_PATH}
     DEFINE_SYMBOL CVAPI_EXPORTS
     )