Android: Added sf::getNativeActivity() to retrieve a handle to the current activity

This is only implemented for Android builds and requires the user to include the sub-header specifically. Other platforms will trigger a compiler error, if they try to include this header file.

doc/doxyfile.in

@@ -2377,3 +2377,21 @@ GENERATE_LEGEND        = YES
 # This tag requires that the tag HAVE_DOT is set to YES.
 
 DOT_CLEANUP            = YES
+
+#---------------------------------------------------------------------------
+# SFML specific aliases
+#---------------------------------------------------------------------------
+
+# sfplatform{platform(s)}
+# sfplatform{platform(s), header}
+#
+# Warns the user that some specific class or function is only available on
+# specific platforms.
+#
+# This shouldn't be used for incomplete implementations. It's meant for things
+# that will never appear on another platform, e.g. Android's native activity.
+#
+# If a header is given, the user is informed, that this header must be included
+# for the mentioned element to be defined.
+ALIASES               += sfplatform{1}="<dl class=\"attention\"><dt>Platform Limitation</dt><dd><b>This is only available on \1.</b></dd></dl>"
+ALIASES               += sfplatform{2}="<dl class=\"attention\"><dt>Platform Limitation</dt><dd><b>This is only available on \1</b> and to use it, you'll have to specifically include \2 in your code.</dd></dl>"

examples/android/AndroidManifest.xml

@@ -10,6 +10,8 @@
     <uses-sdk android:minSdkVersion="9"
               android:targetSdkVersion="19" />
 
+    <uses-permission android:name="android.permission.VIBRATE" />
+    
     <application android:label="@string/app_name"
                  android:icon="@drawable/sfml_logo"
                  android:hasCode="false"

examples/android/jni/main.cpp

@@ -4,7 +4,76 @@
 #include <SFML/Audio.hpp>
 #include <SFML/Network.hpp>
 
+// Do we want to showcase direct JNI/NDK interaction?
+// Undefine this to get real cross-platform code.
+#define USE_JNI
 
+#if defined(USE_JNI)
+// These headers are only needed for direct NDK/JDK interaction
+#include <jni.h>
+#include <android/native_activity.h>
+
+// Since we want to get the native activity from SFML, we'll have to use an
+// extra header here:
+#include <SFML/System/NativeActivity.hpp>
+
+// NDK/JNI sub example - call Java code from native code
+int vibrate(sf::Time duration)
+{
+    // First we'll need the native activity handle
+    ANativeActivity *activity = sf::getNativeActivity();
+    
+    // Retrieve the JVM and JNI environment
+    JavaVM* vm = activity->vm;
+    JNIEnv* env = activity->env;
+
+    // First, attach this thread to the main thread
+    JavaVMAttachArgs attachargs;
+    attachargs.version = JNI_VERSION_1_6;
+    attachargs.name = "NativeThread";
+    attachargs.group = NULL;
+    jint res = vm->AttachCurrentThread(&env, &attachargs);
+
+    if (res == JNI_ERR)
+        return EXIT_FAILURE;
+
+    // Retrieve class information
+    jclass natact = env->FindClass("android/app/NativeActivity");
+    jclass context = env->FindClass("android/content/Context");
+    
+    // Get the value of a constant
+    jfieldID fid = env->GetStaticFieldID(context, "VIBRATOR_SERVICE", "Ljava/lang/String;");
+    jobject svcstr = env->GetStaticObjectField(context, fid);
+    
+    // Get the method 'getSystemService' and call it
+    jmethodID getss = env->GetMethodID(natact, "getSystemService", "(Ljava/lang/String;)Ljava/lang/Object;");
+    jobject vib_obj = env->CallObjectMethod(activity->clazz, getss, svcstr);
+    
+    // Get the object's class and retrieve the member name
+    jclass vib_cls = env->GetObjectClass(vib_obj);
+    jmethodID vibrate = env->GetMethodID(vib_cls, "vibrate", "(J)V"); 
+    
+    // Determine the timeframe
+    jlong length = duration.asMilliseconds();
+    
+    // Bzzz!
+    env->CallVoidMethod(vib_obj, vibrate, length);
+
+    // Free references
+    env->DeleteLocalRef(vib_obj);
+    env->DeleteLocalRef(vib_cls);
+    env->DeleteLocalRef(svcstr);
+    env->DeleteLocalRef(context);
+    env->DeleteLocalRef(natact);
+    
+    // Detach thread again
+    vm->DetachCurrentThread();
+}
+#endif
+
+// This is the actual Android example. You don't have to write any platform
+// specific code, unless you want to use things not directly exposed.
+// ('vibrate()' in this example; undefine 'USE_JNI' above to disable it)
 int main(int argc, char *argv[])
 {
     sf::RenderWindow window(sf::VideoMode::getDesktopMode(), "");
@@ -31,23 +100,26 @@ int main(int argc, char *argv[])
 
         while (window.pollEvent(event))
         {
-            if (event.type == sf::Event::Closed)
+            switch (event.type)
             {
-                window.close();
+                case sf::Event::Closed:
+                    window.close();
+                    break;
+                case sf::Event::Resized:
+                    view.setSize(event.size.width, event.size.height);
+                    view.setCenter(event.size.width/2, event.size.height/2);
+                    window.setView(view);
+                    break;
+                case sf::Event::TouchBegan:
+                    if (event.touch.finger == 0)
+                    {
+                        image.setPosition(event.touch.x, event.touch.y);
+#if defined(USE_JNI)
+                        vibrate(sf::milliseconds(10));
+#endif
+                    }
+                    break;
             }
-
-            if (event.type == sf::Event::Resized)
-            {
-                view.setSize(event.size.width, event.size.height);
-                view.setCenter(event.size.width/2, event.size.height/2);
-                window.setView(view);
-            }
-        }
-
-        if (sf::Touch::isDown(0))
-        {
-            sf::Vector2i position = sf::Touch::getPosition(0);
-            image.setPosition(position.x, position.y);
         }
 
         window.clear(sf::Color::White);

include/SFML/System/NativeActivity.hpp

@@ -0,0 +1,62 @@
+////////////////////////////////////////////////////////////
+//
+// SFML - Simple and Fast Multimedia Library
+// Copyright (C) 2007-2015 Laurent Gomila (laurent@sfml-dev.org)
+//
+// This software is provided 'as-is', without any express or implied warranty.
+// In no event will the authors be held liable for any damages arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it freely,
+// subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented;
+//    you must not claim that you wrote the original software.
+//    If you use this software in a product, an acknowledgment
+//    in the product documentation would be appreciated but is not required.
+//
+// 2. Altered source versions must be plainly marked as such,
+//    and must not be misrepresented as being the original software.
+//
+// 3. This notice may not be removed or altered from any source distribution.
+//
+////////////////////////////////////////////////////////////
+
+#ifndef SFML_NATIVEACTIVITY_HPP
+#define SFML_NATIVEACTIVITY_HPP
+
+
+////////////////////////////////////////////////////////////
+// Headers
+////////////////////////////////////////////////////////////
+#include <SFML/System/Export.hpp>
+
+
+#if !defined(SFML_SYSTEM_ANDROID)
+#error NativeActivity.hpp: This header is Android only.
+#endif
+
+
+struct ANativeActivity;
+
+namespace sf
+{
+////////////////////////////////////////////////////////////
+/// \ingroup system
+/// \brief Return a pointer to the Android native activity
+///
+/// You shouldn't have to use this function, unless you want
+/// to implement very specific details, that SFML doesn't
+/// support, or to use a workaround for a known issue.
+///
+/// \return Pointer to Android native activity structure
+///
+/// \sfplatform{Android,SFML/System/NativeActivity.hpp}
+///
+////////////////////////////////////////////////////////////
+SFML_SYSTEM_API ANativeActivity* getNativeActivity();
+
+} // namespace sf
+
+
+#endif // SFML_NATIVEACTIVITY_HPP

src/SFML/System/Android/NativeActivity.cpp

@@ -0,0 +1,39 @@
+////////////////////////////////////////////////////////////
+//
+// SFML - Simple and Fast Multimedia Library
+// Copyright (C) 2007-2015 Laurent Gomila (laurent@sfml-dev.org)
+//
+// This software is provided 'as-is', without any express or implied warranty.
+// In no event will the authors be held liable for any damages arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it freely,
+// subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented;
+//    you must not claim that you wrote the original software.
+//    If you use this software in a product, an acknowledgment
+//    in the product documentation would be appreciated but is not required.
+//
+// 2. Altered source versions must be plainly marked as such,
+//    and must not be misrepresented as being the original software.
+//
+// 3. This notice may not be removed or altered from any source distribution.
+//
+////////////////////////////////////////////////////////////
+
+////////////////////////////////////////////////////////////
+// Headers
+////////////////////////////////////////////////////////////
+#include <SFML/System/NativeActivity.hpp>
+#include <SFML/System/Android/Activity.hpp>
+
+namespace sf
+{
+////////////////////////////////////////////////////////////
+ANativeActivity* getNativeActivity()
+{
+    return priv::getActivity()->activity;
+}
+
+} // namespace sf

src/SFML/System/CMakeLists.txt

@@ -14,6 +14,7 @@ set(SRC
     ${INCROOT}/Lock.hpp
     ${SRCROOT}/Mutex.cpp
     ${INCROOT}/Mutex.hpp
+    ${INCROOT}/NativeActivity.hpp
     ${INCROOT}/NonCopyable.hpp
     ${SRCROOT}/Sleep.cpp
     ${INCROOT}/Sleep.hpp
@@ -75,6 +76,7 @@ else()
         set(PLATFORM_SRC ${PLATFORM_SRC}
             ${SRCROOT}/Android/Activity.hpp
             ${SRCROOT}/Android/Activity.cpp
+            ${SRCROOT}/Android/NativeActivity.cpp
             ${SRCROOT}/Android/ResourceStream.cpp
             ${SRCROOT}/Android/ResourceStream.cpp
         )