Qt: add Android packaging support

Introduce an android directory under qt and allow one to package bitcoin-qt for Android by running make apk.
Add bitcoin-qt Android build instructions.

10 files changed, 123 insertions, 0 deletions

diff --git a/src/qt/android/AndroidManifest.xml b/src/qt/android/AndroidManifest.xml
new file mode 100644
index 0000000000..abb88fe89d
--- /dev/null
+++ b/src/qt/android/AndroidManifest.xml
@@ -0,0 +1,38 @@
+<?xml version='1.0' encoding='utf-8'?>
+<manifest package="org.bitcoincore.qt" xmlns:android="http://schemas.android.com/apk/res/android" android:versionName="1.0" android:versionCode="1" android:installLocation="auto">
+    <uses-sdk android:targetSdkVersion="24"/>
+
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+
+    <uses-feature android:glEsVersion="0x00020000" android:required="true" />
+
+    <supports-screens android:largeScreens="true" android:normalScreens="true" android:anyDensity="true" android:smallScreens="true"/>
+
+    <application android:hardwareAccelerated="true" android:name="org.qtproject.qt5.android.bindings.QtApplication" android:label="Bitcoin Core">
+        <activity android:configChanges="orientation|uiMode|screenLayout|screenSize|smallestScreenSize|layoutDirection|locale|fontScale|keyboard|keyboardHidden|navigation|mcc|mnc|density"
+                  android:name="org.bitcoincore.qt.BitcoinQtActivity"
+                  android:label="Bitcoin Core"
+                  android:icon="@drawable/bitcoin"
+                  android:screenOrientation="unspecified"
+                  android:launchMode="singleTop">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN"/>
+                <category android:name="android.intent.category.LAUNCHER"/>
+            </intent-filter>
+
+            <meta-data android:name="android.app.arguments" android:value="-testnet"/>
+            <meta-data android:name="android.app.lib_name" android:value="bitcoin-qt"/>
+            <meta-data android:name="android.app.repository" android:value="default"/>
+            <meta-data android:name="android.app.bundle_local_qt_libs" android:value="1"/>
+            <meta-data android:name="android.app.use_local_qt_libs" android:value="1"/>
+            <meta-data android:name="android.app.libs_prefix" android:value="/data/local/tmp/qt/"/>
+            <meta-data android:name="android.app.system_libs_prefix" android:value="/system/lib/"/>
+            <meta-data android:name="android.app.background_running" android:value="true"/>
+            <meta-data android:name="android.app.auto_screen_scale_factor" android:value="true"/>
+            <meta-data android:name="android.app.extract_android_style" android:value="default"/>
+    </activity>
+
+    </application>
+</manifest>
diff --git a/src/qt/android/build.gradle b/src/qt/android/build.gradle
new file mode 100644
index 0000000000..4c36e79db8
--- /dev/null
+++ b/src/qt/android/build.gradle
@@ -0,0 +1,52 @@
+buildscript {
+    repositories {
+        google()
+        jcenter()
+    }
+
+    dependencies {
+        classpath 'com.android.tools.build:gradle:3.1.0'
+    }
+}
+
+repositories {
+    google()
+    jcenter()
+}
+
+apply plugin: 'com.android.application'
+
+dependencies {
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+}
+
+android {
+    compileSdkVersion androidCompileSdkVersion.toInteger()
+
+    buildToolsVersion androidBuildToolsVersion
+
+    sourceSets {
+        main {
+            manifest.srcFile 'AndroidManifest.xml'
+            java.srcDirs = [qt5AndroidDir + '/src', 'src', 'java']
+            aidl.srcDirs = [qt5AndroidDir + '/src', 'src', 'aidl']
+            res.srcDirs = [qt5AndroidDir + '/res', 'res']
+            resources.srcDirs = ['src']
+            renderscript.srcDirs = ['src']
+            assets.srcDirs = ['assets']
+            jniLibs.srcDirs = ['libs']
+       }
+    }
+
+    lintOptions {
+        abortOnError false
+    }
+
+    dexOptions {
+        javaMaxHeapSize '4g'
+    }
+
+    defaultConfig {
+        minSdkVersion 24
+    }
+}
diff --git a/src/qt/android/gradle.properties b/src/qt/android/gradle.properties
new file mode 100644
index 0000000000..838870f62d
--- /dev/null
+++ b/src/qt/android/gradle.properties
@@ -0,0 +1,4 @@
+androidBuildToolsVersion=28.0.3
+androidCompileSdkVersion=28
+qt5AndroidDir=new File(".").absolutePath
+org.gradle.jvmargs=-Xmx4608M
diff --git a/src/qt/android/res/drawable-hdpi/bitcoin.png b/src/qt/android/res/drawable-hdpi/bitcoin.png
new file mode 100644
index 0000000000..31a556a35f
--- /dev/null
+++ b/src/qt/android/res/drawable-hdpi/bitcoin.png
diff --git a/src/qt/android/res/drawable-ldpi/bitcoin.png b/src/qt/android/res/drawable-ldpi/bitcoin.png
new file mode 100644
index 0000000000..76d80d4196
--- /dev/null
+++ b/src/qt/android/res/drawable-ldpi/bitcoin.png
diff --git a/src/qt/android/res/drawable-mdpi/bitcoin.png b/src/qt/android/res/drawable-mdpi/bitcoin.png
new file mode 100644
index 0000000000..c2aeab851a
--- /dev/null
+++ b/src/qt/android/res/drawable-mdpi/bitcoin.png
diff --git a/src/qt/android/res/drawable-xhdpi/bitcoin.png b/src/qt/android/res/drawable-xhdpi/bitcoin.png
new file mode 100644
index 0000000000..2bd5e3defc
--- /dev/null
+++ b/src/qt/android/res/drawable-xhdpi/bitcoin.png
diff --git a/src/qt/android/res/drawable-xxhdpi/bitcoin.png b/src/qt/android/res/drawable-xxhdpi/bitcoin.png
new file mode 100644
index 0000000000..d236cf2132
--- /dev/null
+++ b/src/qt/android/res/drawable-xxhdpi/bitcoin.png
diff --git a/src/qt/android/res/drawable-xxxhdpi/bitcoin.png b/src/qt/android/res/drawable-xxxhdpi/bitcoin.png
new file mode 100644
index 0000000000..bb1dbc3554
--- /dev/null
+++ b/src/qt/android/res/drawable-xxxhdpi/bitcoin.png
diff --git a/src/qt/android/src/org/bitcoincore/qt/BitcoinQtActivity.java b/src/qt/android/src/org/bitcoincore/qt/BitcoinQtActivity.java
new file mode 100644
index 0000000000..cf3b4f6668
--- /dev/null
+++ b/src/qt/android/src/org/bitcoincore/qt/BitcoinQtActivity.java
@@ -0,0 +1,29 @@
+package org.bitcoincore.qt;
+
+import android.os.Bundle;
+import android.system.ErrnoException;
+import android.system.Os;
+
+import org.qtproject.qt5.android.bindings.QtActivity;
+
+import java.io.File;
+
+public class BitcoinQtActivity extends QtActivity
+{
+    @Override
+    public void onCreate(Bundle savedInstanceState)
+    {
+        final File bitcoinDir = new File(getFilesDir().getAbsolutePath() + "/.bitcoin");
+        if (!bitcoinDir.exists()) {
+            bitcoinDir.mkdir();
+        }
+
+        try {
+            Os.setenv("QT_QPA_PLATFORM", "android", true);
+        } catch (ErrnoException e) {
+            e.printStackTrace();
+        }
+
+        super.onCreate(savedInstanceState);
+    }
+}