support multiple Activities

meson.build

@@ -83,6 +83,7 @@ libtranslationlayer_so = shared_library('translation_layer_main', [
                                                                   	'src/api-impl-jni/android_app_NativeActivity.c',
                                                                   	'src/api-impl-jni/android_opengl_GLES20.c',
                                                                   	'src/api-impl-jni/location/android_location_LocationManager.c',
+                                                                  	'src/api-impl-jni/app/android_app_Activity.c',
                                                                   ] + marshal_files,
                                                                   install: true,
                                                                   install_dir : get_option('libdir') / 'java/dex/android_translation_layer/natives',

src/api-impl-jni/app/android_app_Activity.c

@@ -0,0 +1,99 @@
+#include <gtk/gtk.h>
+
+#include <jni.h>
+
+#include "../defines.h"
+#include "../util.h"
+#include "android_app_Activity.h"
+#include "../generated_headers/android_app_Activity.h"
+
+static GList *activity_backlog = NULL;
+static jobject activity_current = NULL;
+
+static void activity_close(JNIEnv *env, jobject activity) {
+	// in case some exception was left unhandled in native code, print it here so we don't confuse it with an exception thrown by onDestroy
+	if((*env)->ExceptionCheck(env)) {
+		fprintf(stderr, "app_exit: seems there was a pending exception... :");
+		(*env)->ExceptionDescribe(env);
+	}
+
+	/* -- run the main activity's onDestroy -- */
+	(*env)->CallVoidMethod(env, activity, handle_cache.apk_main_activity.onDestroy, NULL);
+	if((*env)->ExceptionCheck(env))
+		(*env)->ExceptionDescribe(env);
+}
+
+static void activity_update_current(JNIEnv *env) {
+	jobject activity_new = activity_backlog ? g_list_first(activity_backlog)->data : NULL;
+
+	if (activity_current != activity_new) {
+		if (activity_current) {
+			(*env)->CallVoidMethod(env, activity_current, handle_cache.apk_main_activity.onPause);
+			if((*env)->ExceptionCheck(env))
+				(*env)->ExceptionDescribe(env);
+
+			(*env)->CallVoidMethod(env, activity_current, handle_cache.apk_main_activity.onStop);
+			if((*env)->ExceptionCheck(env))
+				(*env)->ExceptionDescribe(env);
+		}
+		if (activity_new) {
+			(*env)->CallVoidMethod(env, activity_new, handle_cache.apk_main_activity.onStart);
+			if((*env)->ExceptionCheck(env))
+				(*env)->ExceptionDescribe(env);
+
+			(*env)->CallVoidMethod(env, activity_new, handle_cache.apk_main_activity.onResume);
+			if((*env)->ExceptionCheck(env))
+				(*env)->ExceptionDescribe(env);
+		}
+		activity_current = activity_new;
+	}
+}
+
+void activity_window_ready(void) {
+	JNIEnv *env = get_jni_env();
+
+	for (GList *l = activity_backlog; l != NULL; l = l->next) {
+		(*env)->CallVoidMethod(env, l->data, handle_cache.apk_main_activity.onWindowFocusChanged, true);
+		if((*env)->ExceptionCheck(env))
+			(*env)->ExceptionDescribe(env);
+	}
+}
+
+void activity_close_all(void) {
+	GList *activities, *l;
+	JNIEnv *env = get_jni_env();
+	// local backup of the backlog
+	activities = activity_backlog;
+	// deactivate all activities
+	activity_backlog = NULL;
+	activity_update_current(env);
+	// destroy all activities
+	for (l = activities; l != NULL; l = l->next) {
+		activity_close(env, l->data);
+		_UNREF(l->data);
+	}
+	g_list_free(activities);
+}
+
+void activity_start(JNIEnv *env, jobject activity_object) {
+	/* -- run the activity's onCreate -- */
+	(*env)->CallVoidMethod(env, activity_object, handle_cache.apk_main_activity.onCreate, NULL);
+	if((*env)->ExceptionCheck(env))
+		(*env)->ExceptionDescribe(env);
+
+	activity_backlog = g_list_prepend(activity_backlog, _REF(activity_object));
+	activity_update_current(env);
+}
+
+JNIEXPORT void JNICALL Java_android_app_Activity_nativeFinish(JNIEnv *env, jobject this, jlong window) {
+	activity_backlog = g_list_remove(activity_backlog, this);
+	activity_update_current(env);
+	activity_close(env, this);
+	_UNREF(this);
+	if (activity_backlog == NULL)
+		gtk_window_close(GTK_WINDOW(_PTR(window)));
+}
+
+JNIEXPORT void JNICALL Java_android_app_Activity_nativeStartActivity(JNIEnv *env, jclass class, jobject activity) {
+	activity_start(env, activity);
+}

src/api-impl-jni/app/android_app_Activity.h

@@ -0,0 +1,5 @@
+#include <jni.h>
+
+void activity_start(JNIEnv *env, jobject activity_object);
+void activity_window_ready(void);
+void activity_close_all(void);

src/api-impl-jni/generated_headers/android_app_Activity.h

@@ -0,0 +1,31 @@
+/* DO NOT EDIT THIS FILE - it is machine generated */
+#include <jni.h>
+/* Header for class android_app_Activity */
+
+#ifndef _Included_android_app_Activity
+#define _Included_android_app_Activity
+#ifdef __cplusplus
+extern "C" {
+#endif
+#undef android_app_Activity_MODE_PRIVATE
+#define android_app_Activity_MODE_PRIVATE 0L
+/*
+ * Class:     android_app_Activity
+ * Method:    nativeFinish
+ * Signature: (J)V
+ */
+JNIEXPORT void JNICALL Java_android_app_Activity_nativeFinish
+  (JNIEnv *, jobject, jlong);
+
+/*
+ * Class:     android_app_Activity
+ * Method:    nativeStartActivity
+ * Signature: (Landroid/app/Activity;)V
+ */
+JNIEXPORT void JNICALL Java_android_app_Activity_nativeStartActivity
+  (JNIEnv *, jclass, jobject);
+
+#ifdef __cplusplus
+}
+#endif
+#endif

src/api-impl-jni/util.c

@@ -51,6 +51,8 @@ void set_up_handle_cache(JNIEnv *env)
 	handle_cache.apk_main_activity.onWindowFocusChanged = _METHOD(handle_cache.apk_main_activity.class, "onWindowFocusChanged", "(Z)V");
 	handle_cache.apk_main_activity.onResume = _METHOD(handle_cache.apk_main_activity.class, "onResume", "()V");
 	handle_cache.apk_main_activity.onDestroy = _METHOD(handle_cache.apk_main_activity.class, "onDestroy", "()V");
+	handle_cache.apk_main_activity.onStop = _METHOD(handle_cache.apk_main_activity.class, "onStop", "()V");
+	handle_cache.apk_main_activity.onPause = _METHOD(handle_cache.apk_main_activity.class, "onPause", "()V");
 
 	handle_cache.attribute_set.class = _REF((*env)->FindClass(env, "android/util/AttributeSet"));
 	if((*env)->ExceptionCheck(env))

src/api-impl-jni/util.h

@@ -8,12 +8,13 @@
 struct handle_cache {
 	struct {
 		jclass class;
-		jobject object;
 		jmethodID onCreate;
 		jmethodID onStart;
 		jmethodID onResume;
 		jmethodID onWindowFocusChanged;
 		jmethodID onDestroy;
+		jmethodID onStop;
+		jmethodID onPause;
 	} apk_main_activity;
 	struct {
 		jclass class;
@@ -78,6 +79,8 @@ struct handle_cache {
 
 extern struct handle_cache handle_cache;
 
+JNIEnv * get_jni_env(void);
+
 const char * attribute_set_get_string(JNIEnv *env, jobject attrs, char *attribute, char *schema);
 int attribute_set_get_int(JNIEnv *env, jobject attrs, char *attribute, char *schema, int default_value);
 void set_up_handle_cache(JNIEnv *env);

src/api-impl/android/app/Activity.java

@@ -29,6 +29,7 @@ public class Activity extends Context {
 	LayoutInflater layout_inflater;
 	Window window = new Window();
 	int requested_orientation = -1 /*ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED*/; // dummy
+	private Intent intent;
 
 	/**
 	 * Helper function to be called from native code to construct main activity
@@ -56,6 +57,7 @@ public class Activity extends Context {
 
 	public Activity() {
 		layout_inflater = new LayoutInflater();
+		intent = new Intent();
 	}
 
 	public View root_view;
@@ -77,8 +79,7 @@ public class Activity extends Context {
 	}
 
 	public Intent getIntent() {
-//		return null; // this is the main activity, and it wasn't opened as a result of someone calling "open with"
-		return new Intent(); // seems some apps don't consider this nullable...
+		return intent;
 	}
 
 	public int getRequestedOrientation() {
@@ -223,10 +224,45 @@ public class Activity extends Context {
 
 	public void startActivityForResult(Intent intent, int requestCode) {
 		System.out.println("startActivityForResult(" + intent + ", " + requestCode + ") called, but we don't currently support multiple activities");
-		onActivityResult(requestCode, 0 /*RESULT_CANCELED*/, new Intent()); // RESULT_CANCELED is the only pre-defined return value, so hopefully it works out for us
+		if (intent.getComponent() != null) {
+			try {
+				Class<? extends Activity> cls = Class.forName(intent.getComponent().getClassName()).asSubclass(Activity.class);
+				Constructor<? extends Activity> constructor = cls.getConstructor();
+				Activity activity = constructor.newInstance();
+				activity.intent = intent;
+				activity.window = getWindow();
+				nativeStartActivity(activity);
+			} catch (ClassNotFoundException | NoSuchMethodException | SecurityException | InstantiationException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+				onActivityResult(requestCode, 0 /*RESULT_CANCELED*/, new Intent()); // RESULT_CANCELED is the only pre-defined return value, so hopefully it works out for us
+			}
+		}
+		else {
+			onActivityResult(requestCode, 0 /*RESULT_CANCELED*/, new Intent()); // RESULT_CANCELED is the only pre-defined return value, so hopefully it works out for us
+		}
+	}
+
+	public void startActivity(Intent intent) {
+		System.out.println("startActivity(" + intent + ") called");
+		try {
+			Class<? extends Activity> cls = Class.forName(intent.getComponent().getClassName()).asSubclass(Activity.class);
+			Constructor<? extends Activity> constructor = cls.getConstructor();
+			Activity activity = constructor.newInstance();
+			activity.intent = intent;
+			activity.window = getWindow();
+			nativeStartActivity(activity);
+		} catch (ClassNotFoundException | NoSuchMethodException | SecurityException | InstantiationException | IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+			e.printStackTrace();
+		}
 	}
 
 	public final void showDialog(int id) {
 		System.out.println("Activity.showDialog(" + id + ") called");
 	}
+
+	public void finish() {
+		nativeFinish(getWindow().native_window);
+	}
+
+	private native void nativeFinish(long native_window);
+	private static native void nativeStartActivity(Activity activity);
 }

src/main-executable/main.c

@@ -5,6 +5,7 @@
 
 #include "../api-impl-jni/defines.h"
 #include "../api-impl-jni/util.h"
+#include "../api-impl-jni/app/android_app_Activity.h"
 
 #include <dlfcn.h>
 #include <errno.h>
@@ -34,17 +35,7 @@ GtkWidget *window;
 
 gboolean app_exit(GtkWindow* self, JNIEnv *env) // TODO: do more cleanup?
 {
-	// in case some exception was left unhandled in native code, print it here so we don't confuse it with an exception thrown by onDestroy
-	if((*env)->ExceptionCheck(env)) {
-		fprintf(stderr, "app_exit: seems there was a pending exception... :");
-		(*env)->ExceptionDescribe(env);
-	}
-
-	/* -- run the main activity's onDestroy -- */
-	(*env)->CallVoidMethod(env, handle_cache.apk_main_activity.object, handle_cache.apk_main_activity.onDestroy, NULL);
-	if((*env)->ExceptionCheck(env))
-		(*env)->ExceptionDescribe(env);
-
+	activity_close_all();
 	return false;
 }
 
@@ -128,10 +119,7 @@ JNIEnv* create_vm(char *api_impl_jar, char *apk_classpath, char *microg_apk, cha
 gboolean hacky_on_window_focus_changed_callback(JNIEnv *env)
 {
 	if(gtk_widget_get_width(window) != 0) {
-		(*env)->CallVoidMethod(env, handle_cache.apk_main_activity.object, handle_cache.apk_main_activity.onWindowFocusChanged, true);
-		if((*env)->ExceptionCheck(env))
-			(*env)->ExceptionDescribe(env);
-
+		activity_window_ready();
 		return G_SOURCE_REMOVE;
 	}
 
@@ -170,6 +158,7 @@ static void open(GtkApplication *app, GFile** files, gint nfiles, const gchar* h
 	int errno_libdir;
 	int errno_localdir;
 	int ret;
+	jobject activity_object;
 
 	char *apk_classpath =  g_file_get_path(files[0]);
 	char *apk_name = g_file_get_basename(files[0]);
@@ -364,26 +353,13 @@ static void open(GtkApplication *app, GFile** files, gint nfiles, const gchar* h
 	prepare_main_looper(env);
 
 	// construct main Activity
-	handle_cache.apk_main_activity.object = _REF((*env)->CallStaticObjectMethod(env, handle_cache.apk_main_activity.class,
+	activity_object = (*env)->CallStaticObjectMethod(env, handle_cache.apk_main_activity.class,
 		_STATIC_METHOD(handle_cache.apk_main_activity.class, "createMainActivity", "(Ljava/lang/String;J)Landroid/app/Activity;"),
-		_JSTRING(d->apk_main_activity_class), _INTPTR(window)));
+		_JSTRING(d->apk_main_activity_class), _INTPTR(window));
 	if((*env)->ExceptionCheck(env))
 		(*env)->ExceptionDescribe(env);
 
-	/* -- run the main activity's onCreate -- */
-
-	(*env)->CallVoidMethod(env, handle_cache.apk_main_activity.object, handle_cache.apk_main_activity.onCreate, NULL);
-	if((*env)->ExceptionCheck(env))
-		(*env)->ExceptionDescribe(env);
-
-//	TODO: some apps wait for this to actually do stuff
-	(*env)->CallVoidMethod(env, handle_cache.apk_main_activity.object, handle_cache.apk_main_activity.onStart);
-	if((*env)->ExceptionCheck(env))
-		(*env)->ExceptionDescribe(env);
-
-	(*env)->CallVoidMethod(env, handle_cache.apk_main_activity.object, handle_cache.apk_main_activity.onResume);
-	if((*env)->ExceptionCheck(env))
-		(*env)->ExceptionDescribe(env);
+	activity_start(env, activity_object);
 
 	g_timeout_add(10, G_SOURCE_FUNC(hacky_on_window_focus_changed_callback), env);