Add script for local Android builds

Similar to the Emscripten scripts, except as a single file. Running this
with `setup` will set up dependencies, then `configure` will run cmake
to configure a Drawpile build. Parameters are passed via environment.

pkg/android/build.bash

@@ -0,0 +1,242 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: MIT
+# Performs local Android builds. Only tested to work on Linux.
+
+carp() {
+    echo "$@" 1>&2
+}
+
+croak() {
+    carp "$@"
+    exit 1
+}
+
+croak_with_usage() {
+    carp
+    carp "Usage:"
+    carp "    $0 setup"
+    carp "        to set up the Android SDK and dependencies"
+    carp "    $0 configure"
+    carp "        to configure the cmake build of Drawpile"
+    carp
+    carp "The following environment variables can be set:"
+    carp "    BUILD_TYPE (release, debug) [$BUILD_TYPE]"
+    carp "    QT_VERSION [$QT_VERSION]"
+    carp "    ANDROID_ABI (armeabi-v7a, arm64-v8a, x86, x86_64) [$ANDROID_ABI]"
+    carp "    ANDROID_BUILD_TOOLS_VERSION [$ANDROID_BUILD_TOOLS_VERSION]"
+    carp "    ANDROID_NDK_VERSION [$ANDROID_NDK_VERSION]"
+    carp "    ANDROID_PLATFORM_VERSION [$ANDROID_PLATFORM_VERSION]"
+    carp "    ANDROID_SDK_DIR [$ANDROID_SDK_DIR]"
+    carp
+    exit 2
+}
+
+install_sdk() {
+    local sdkmanager
+    sdkmanager="$ANDROID_SDK_DIR/cmdline-tools/latest/bin/sdkmanager"
+    if [[ ! -x "$sdkmanager" ]]; then
+        croak "sdkmanager is not an executable file '$sdkmanager'"
+    fi
+    set -xe
+    "$sdkmanager" --install \
+        "build-tools;$ANDROID_BUILD_TOOLS_VERSION" \
+        "ndk;$ANDROID_NDK_VERSION" \
+        'platform-tools' \
+        "platforms;$ANDROID_PLATFORM"
+    set +xe
+}
+
+check_sdk() {
+    local error expected_java_version
+    error=0
+
+    if [[ ! -d $ANDROID_SDK_DIR ]]; then
+        carp "ANDROID_SDK_DIR is not a directory: '$ANDROID_SDK_DIR'"
+        error=1
+    fi
+
+    if [[ ! -d $ANDROID_NDK_DIR ]]; then
+        carp "ANDROID_NDK_DIR is not a directory: '$ANDROID_NDK_DIR'"
+        error=1
+    fi
+
+    if [[ ! -f $ANDROID_TOOLCHAIN_FILE ]]; then
+        carp "ANDROID_TOOLCHAIN_FILE is not a file: '$ANDROID_TOOLCHAIN_FILE'"
+        error=1
+    fi
+
+    case $ANDROID_PLATFORM_VERSION in
+        '34')
+            expected_java_version='17'
+            ;;
+        *)
+            carp "Unknown ANDROID_PLATFORM_VERSION '$ANDROID_PLATFORM_VERSION'"
+            ;;
+    esac
+
+    if [[ -n $expected_java_version ]]; then
+        java_version="$(java -version 2>&1 | perl -0777 -ne '/version\s+"([0-9]+)\./ && print $1')"
+        if [[ "$java_version" != "$expected_java_version" ]]; then
+            carp "Expected Java version '$expected_java_version' for Android $ANDROID_PLATFORM_VERSION, but got '$java_version'"
+            error=1
+        fi
+    fi
+
+    if [[ $error -ne 0 ]]; then
+        exit 1
+    fi
+}
+
+run_build_script() {
+    check_sdk
+    set -xe
+    mkdir -p "$build_source_dir"
+    pushd "$build_source_dir"
+    cmake \
+        -DBUILD_TYPE="$cmake_build_type" \
+        -DCMAKE_PREFIX_PATH="$build_prefix_dir" \
+        -DCMAKE_INSTALL_PREFIX="$build_prefix_dir" \
+        -DANDROID_SDK_ROOT="$ANDROID_SDK_DIR" \
+        -DANDROID_NDK_ROOT="$ANDROID_NDK_DIR" \
+        -DANDROID_ABI="$ANDROID_ABI" \
+        -DANDROID_PLATFORM="$ANDROID_PLATFORM" \
+        -DTARGET_ARCH="$TARGET_ARCH" \
+        -DKEEP_SOURCE_DIRS=ON \
+        -DKEEP_BINARY_DIRS=ON \
+        "$@"
+    popd
+    set +xe
+}
+
+build_qt() {
+    run_build_script \
+        -DQT_VERSION="$QT_VERSION" \
+        -P "$SRC_DIR/.github/scripts/build-qt.cmake"
+}
+
+build_ffmpeg() {
+    run_build_script \
+        -DCMAKE_TOOLCHAIN_FILE="$ANDROID_TOOLCHAIN_FILE" \
+        -P "$SRC_DIR/.github/scripts/build-ffmpeg.cmake"
+}
+
+build_other() {
+    run_build_script \
+        -DCMAKE_TOOLCHAIN_FILE="$ANDROID_TOOLCHAIN_FILE" \
+        -P "$SRC_DIR/.github/scripts/build-other.cmake"
+}
+
+setup() {
+    install_sdk
+    build_qt
+    build_ffmpeg
+    build_other
+    echo
+    echo "Setup for Android complete."
+    echo
+    echo "To configure and build Drawpile now, run:"
+    echo "    $0 configure"
+    echo "    cmake --build $build_dir"
+    echo
+}
+
+configure() {
+    check_sdk
+    set -xe
+    cmake \
+        -DCMAKE_BUILD_TYPE="$cmake_build_type" \
+        -DCMAKE_PREFIX_PATH="$build_prefix_dir" \
+        -DCMAKE_INTERPROCEDURAL_OPTIMIZATION="$cmake_interprocedural_optimization" \
+        -DCMAKE_TOOLCHAIN_FILE="$ANDROID_TOOLCHAIN_FILE" \
+        -DANDROID_ABI="$ANDROID_ABI" \
+        -DANDROID_PLATFORM="$ANDROID_PLATFORM" \
+        -DANDROID_SDK_BUILD_TOOLS_REVISION="$ANDROID_BUILD_TOOLS_VERSION" \
+        -DANDROID_TARGET_SDK_VERSION="$ANDROID_PLATFORM_VERSION" \
+        -DCMAKE_FIND_ROOT_PATH_MODE_PACKAGE=ON \
+        -DCMAKE_FIND_ROOT_PATH_MODE_INCLUDE=BOTH \
+        -DCMAKE_FIND_ROOT_PATH_MODE_LIBRARY=BOTH \
+        -DCMAKE_FIND_ROOT_PATH_MODE_PROGRAM=BOTH \
+        -DBUILTINSERVER=OFF \
+        -DCLANG_TIDY=OFF \
+        -DSERVER=OFF \
+        -DTESTS=OFF \
+        -DTOOLS=OFF \
+        -G Ninja \
+        -S "$SRC_DIR" \
+        -B "$build_dir"
+    set +xe
+}
+
+SCRIPT_DIR="$(readlink -f "$(dirname "$0")")"
+if [[ -z "$SCRIPT_DIR" ]]; then
+    croak "Could not figure out script directory of '$0'"
+fi
+
+: "${BUILD_TYPE:=release}"
+: "${QT_VERSION:=5.15.14}"
+: "${ANDROID_ABI:=arm64-v8a}"
+: "${ANDROID_BUILD_TOOLS_VERSION:=34.0.0-rc3}"
+: "${ANDROID_NDK_VERSION:=27.0.12077973}"
+: "${ANDROID_PLATFORM_VERSION:=34}"
+: "${ANDROID_SDK_DIR=$HOME/Android/Sdk}"
+
+case $ANDROID_ABI in
+    'armeabi-v7a')
+        TARGET_ARCH='arm32'
+        ;;
+    'arm64-v8a')
+        TARGET_ARCH='arm64'
+        ;;
+    'x86')
+        TARGET_ARCH='x86'
+        ;;
+    'x86_64')
+        TARGET_ARCH='x86_64'
+        ;;
+    *)
+        croak "Unknown ANDROID_ABI '$ANDROID_ABI'"
+        ;;
+esac
+
+case $BUILD_TYPE in
+    'debug')
+        cmake_build_type=Debug
+        cmake_interprocedural_optimization=OFF
+        ;;
+    'release')
+        cmake_build_type=Release
+        cmake_interprocedural_optimization=ON
+        ;;
+    *)
+        croak "Unknown BUILD_TYPE '$BUILD_TYPE'"
+        ;;
+esac
+
+build_dir="buildandroid-$ANDROID_ABI-$BUILD_TYPE"
+build_source_dir="$SCRIPT_DIR/build$ANDROID_ABI/$BUILD_TYPE/source"
+build_prefix_dir="$SCRIPT_DIR/build$ANDROID_ABI/$BUILD_TYPE/prefix"
+
+SRC_DIR="$(dirname "$(dirname "$SCRIPT_DIR")")"
+if [[ -z $SRC_DIR ]]; then
+    croak "Couldn't figure out source directory based on '$SCRIPT_DIR'"
+fi
+
+ANDROID_NDK_DIR="$ANDROID_SDK_DIR/ndk/$ANDROID_NDK_VERSION"
+ANDROID_TOOLCHAIN_FILE="$ANDROID_NDK_DIR/build/cmake/android.toolchain.cmake"
+ANDROID_PLATFORM="android-$ANDROID_PLATFORM_VERSION"
+
+if [[ $# -ne 1 ]]; then
+    croak_with_usage
+fi
+
+case $1 in
+    'setup')
+        setup
+        ;;
+    'configure')
+        configure
+        ;;
+    *)
+        croak_with_usage
+        ;;
+esac