ViewTreeObserver: implement onGlobalLayout properly

meson.build

@@ -131,6 +131,7 @@ libtranslationlayer_so = shared_library('translation_layer_main', [
                                                                   	'src/api-impl-jni/views/AndroidLayout.c',
                                                                   	'src/api-impl-jni/views/android_view_View.c',
                                                                   	'src/api-impl-jni/views/android_view_ViewGroup.c',
+                                                                  	'src/api-impl-jni/views/android_view_ViewTreeObserver.c',
                                                                   	'src/api-impl-jni/views/android_view_WindowManagerImpl.c',
                                                                   	'src/api-impl-jni/widgets/WrapperWidget.c',
                                                                   	'src/api-impl-jni/widgets/android_view_SurfaceView.c',

src/api-impl-jni/android_view_Window.c

@@ -53,3 +53,8 @@ JNIEXPORT void JNICALL Java_android_view_Window_set_1layout(JNIEnv *env, jobject
 	if (width > 0 && height > 0)
 		gtk_window_set_default_size(gtk_window, width, height);
 }
+
+JNIEXPORT void JNICALL Java_android_view_Window_set_1jobject(JNIEnv *env, jclass this, jlong window, jobject window_jobj)
+{
+	g_object_set_data(G_OBJECT(window), "jobject", _WEAK_REF(window_jobj));
+}

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

@@ -359,6 +359,14 @@ JNIEXPORT void JNICALL Java_android_view_View_nativeRequestFocus
 JNIEXPORT void JNICALL Java_android_view_View_nativeSetFullscreen
   (JNIEnv *, jobject, jlong, jboolean);
 
+/*
+ * Class:     android_view_View
+ * Method:    native_get_window
+ * Signature: (J)Landroid/view/Window;
+ */
+JNIEXPORT jobject JNICALL Java_android_view_View_native_1get_1window
+  (JNIEnv *, jobject, jlong);
+
 /*
  * Class:     android_view_View
  * Method:    nativeInvalidate

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

@@ -0,0 +1,21 @@
+/* DO NOT EDIT THIS FILE - it is machine generated */
+#include <jni.h>
+/* Header for class android_view_ViewTreeObserver */
+
+#ifndef _Included_android_view_ViewTreeObserver
+#define _Included_android_view_ViewTreeObserver
+#ifdef __cplusplus
+extern "C" {
+#endif
+/*
+ * Class:     android_view_ViewTreeObserver
+ * Method:    native_set_have_global_layout_listeners
+ * Signature: (Z)V
+ */
+JNIEXPORT void JNICALL Java_android_view_ViewTreeObserver_native_1set_1have_1global_1layout_1listeners
+  (JNIEnv *, jobject, jboolean);
+
+#ifdef __cplusplus
+}
+#endif
+#endif

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

@@ -43,6 +43,14 @@ JNIEXPORT void JNICALL Java_android_view_Window_take_1input_1queue
 JNIEXPORT void JNICALL Java_android_view_Window_set_1layout
   (JNIEnv *, jobject, jlong, jint, jint);
 
+/*
+ * Class:     android_view_Window
+ * Method:    set_jobject
+ * Signature: (JLandroid/view/Window;)V
+ */
+JNIEXPORT void JNICALL Java_android_view_Window_set_1jobject
+  (JNIEnv *, jclass, jlong, jobject);
+
 #ifdef __cplusplus
 }
 #endif

src/api-impl-jni/handle_cache.c

@@ -153,4 +153,7 @@ void set_up_handle_cache(JNIEnv *env)
 	handle_cache.parcel.constructor = _METHOD(handle_cache.parcel.class, "<init>", "(JJ)V");
 	handle_cache.parcel.writeParcelable = _METHOD(handle_cache.parcel.class, "writeParcelable", "(Landroid/os/Parcelable;I)V");
 	handle_cache.parcel.readParcelable = _METHOD(handle_cache.parcel.class, "readParcelable", "(Ljava/lang/ClassLoader;)Landroid/os/Parcelable;");
+
+	handle_cache.view_tree_observer.class = _REF((*env)->FindClass(env, "android/view/ViewTreeObserver"));
+	handle_cache.view_tree_observer.dispatchOnGlobalLayout = _METHOD(handle_cache.view_tree_observer.class, "dispatchOnGlobalLayout", "()V");
 }

src/api-impl-jni/handle_cache.h

@@ -166,6 +166,10 @@ struct handle_cache {
 		jmethodID writeParcelable;
 		jmethodID readParcelable;
 	} parcel;
+	struct {
+		jclass class;
+		jmethodID dispatchOnGlobalLayout;
+	} view_tree_observer;
 };
 
 extern struct handle_cache handle_cache;

src/api-impl-jni/views/android_view_View.c

@@ -307,8 +307,10 @@ void _setOnTouchListener(JNIEnv *env, jobject this, GtkWidget *widget)
 		gtk_widget_add_controller(widget, controller);
 		g_object_set_data(G_OBJECT(widget), "on_intercept_touch_listener", controller);
 	}
-	if (!wrapper->needs_allocation && (wrapper->layout_width || wrapper->layout_height))
+
-		gtk_widget_size_allocate(GTK_WIDGET(wrapper), &(GtkAllocation){.x = 0, .y = 0, .width = wrapper->layout_width, .height = wrapper->layout_height}, 0);
+	if (!wrapper->needs_allocation && (wrapper->real_width || wrapper->real_height))
+		gtk_widget_size_allocate(GTK_WIDGET(wrapper), &(GtkAllocation){.x = 0, .y = 0, .width = wrapper->real_width, .height = wrapper->real_height}, 0);
+
 	wrapper->needs_allocation = true;
 	gtk_widget_set_overflow(GTK_WIDGET(wrapper), GTK_OVERFLOW_HIDDEN);
 }
@@ -340,11 +342,6 @@ JNIEXPORT jint JNICALL Java_android_view_View_getWidth(JNIEnv *env, jobject this
 {
 	GtkWidget *widget = GTK_WIDGET(_PTR(_GET_LONG_FIELD(this, "widget")));
 
-/* FIXME: is this needed in Gtk4?
-	GtkAllocation alloc;
-	gtk_widget_get_allocation(widget, &alloc);
-	printf("widget size is currently %dx%d\n", alloc.width, alloc.height);
-*/
 	if (ATL_IS_ANDROID_LAYOUT(gtk_widget_get_layout_manager(widget))) {
 		AndroidLayout *layout = ATL_ANDROID_LAYOUT(gtk_widget_get_layout_manager(widget));
 		return layout->real_width;
@@ -409,8 +406,6 @@ JNIEXPORT void JNICALL Java_android_view_View_native_1setLayoutParams(JNIEnv *en
 	}
 
 	if (weight > 0.f) {
-		printf(":::-: setting weight: %f\n", weight);
-
 		hexpand = TRUE;
 		vexpand = TRUE;
 	}
@@ -534,10 +529,8 @@ JNIEXPORT jlong JNICALL Java_android_view_View_native_1constructor(JNIEnv *env,
 		gtk_widget_add_controller(widget, controller);
 	}
 
-	if (_METHOD(class, "onAttachedToWindow", "()V") != handle_cache.view.onAttachedToWindow)
+	g_signal_connect(wrapper, "map", G_CALLBACK(java_method_cb), handle_cache.view.onAttachedToWindow);
-		g_signal_connect(wrapper, "map", G_CALLBACK(java_method_cb), handle_cache.view.onAttachedToWindow);
+	g_signal_connect(wrapper, "unmap", G_CALLBACK(java_method_cb), handle_cache.view.onDetachedFromWindow);
-	if (_METHOD(class, "onDetachedFromWindow", "()V") != handle_cache.view.onDetachedFromWindow)
-		g_signal_connect(wrapper, "unmap", G_CALLBACK(java_method_cb), handle_cache.view.onDetachedFromWindow);
 
 	return _INTPTR(widget);
 }
@@ -870,8 +863,15 @@ JNIEXPORT void JNICALL Java_android_view_View_native_1keep_1screen_1on(JNIEnv *e
 	}
 }
 
+
 JNIEXPORT jboolean JNICALL Java_android_view_View_nativeIsAttachedToWindow(JNIEnv *env, jobject this, jlong widget_ptr)
 {
 	GtkWidget *widget = GTK_WIDGET(_PTR(widget_ptr));
 	return gtk_widget_get_mapped(widget);
 }
+
+JNIEXPORT jobject JNICALL Java_android_view_View_native_1get_1window(JNIEnv *env, jobject this, jlong widget_ptr)
+{
+	GtkWidget *widget = GTK_WIDGET(_PTR(widget_ptr));
+	return g_object_get_data(G_OBJECT(gtk_widget_get_root(widget)), "jobject");
+}

src/api-impl-jni/views/android_view_ViewTreeObserver.c

@@ -0,0 +1,44 @@
+#include <gtk/gtk.h>
+
+#include "../defines.h"
+#include "../util.h"
+#include "../generated_headers/android_view_ViewTreeObserver.h"
+
+static void on_global_layout_callback(GdkFrameClock *clock, jobject view_tree_observer)
+{
+	JNIEnv *env = get_jni_env();
+	(*env)->CallVoidMethod(env, view_tree_observer, handle_cache.view_tree_observer.dispatchOnGlobalLayout);
+	if((*env)->ExceptionCheck(env)) {
+		(*env)->ExceptionDescribe(env);
+		(*env)->ExceptionClear(env);
+	}
+}
+
+extern GtkWidget *window;
+
+void _gdb_force_java_stack_trace(void);
+
+JNIEXPORT void JNICALL Java_android_view_ViewTreeObserver_native_1set_1have_1global_1layout_1listeners(JNIEnv *env, jobject this, jboolean have_listeners)
+{
+	GtkWidget *window =_PTR(_GET_LONG_FIELD(this, "window"));
+
+	if(!window) {
+		fprintf(stderr, "Java_android_view_ViewTreeObserver_native_1set_1have_1global_1layout_1listeners: no window\n");
+		return;
+	}
+
+	gulong signal_handle = _GET_LONG_FIELD(this, "onGlobalLayout_signal_handle");
+	GdkFrameClock *clock = gtk_widget_get_frame_clock(window);
+
+	if(have_listeners && !signal_handle) {
+		/* this adds our callback before the existing handler, which means we effectively execute before the paint phase (after layout) */
+		signal_handle = g_signal_connect(G_OBJECT(clock), "paint", G_CALLBACK(on_global_layout_callback), _REF(this)); // FIXME: cleanup callback for _UNREF
+		_SET_LONG_FIELD(this, "onGlobalLayout_signal_handle", signal_handle);
+	} else if (!have_listeners && signal_handle) {
+		g_signal_handler_disconnect(G_OBJECT(clock), signal_handle);
+		_SET_LONG_FIELD(this, "onGlobalLayout_signal_handle", 0);
+	} else {
+		fprintf(stderr, "Java_android_view_ViewTreeObserver_native_1set_1have_1global_1layout_1listeners: invalid state: have_listeners: %d, signal_handle: 0x%016w64x\n", have_listeners, signal_handle);
+		exit(1);
+	}
+}

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

@@ -66,7 +66,7 @@ public class Activity extends ContextThemeWrapper implements Window.Callback, La
 		Class<? extends Activity> cls = Class.forName(className).asSubclass(Activity.class);
 		Constructor<? extends Activity> constructor = cls.getConstructor();
 		Activity activity = constructor.newInstance();
-		activity.window.native_window = native_window;
+		activity.window.set_native_window(native_window);
 		activity.intent = intent;
 		activity.attachBaseContext(new Context());
 		activity.setTheme(themeResId);

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

@@ -40,7 +40,7 @@ public class Dialog implements Window.Callback, DialogInterface {
 			window.setBackgroundDrawable(background);
 		ta.recycle();
 
-		window.native_window = nativePtr;
+		window.set_native_window(nativePtr);
 	}
 
 	public Dialog(Context context) {

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

@@ -139,7 +139,7 @@ public class Instrumentation {
 	                            Intent intent, ActivityInfo info, CharSequence title, Activity parent,
 	                            String id, Object lastNonConfigurationInstance) throws InstantiationException, IllegalAccessException {
 		Activity activity = (Activity)clazz.newInstance();
-		activity.getWindow().native_window = Context.this_application.native_window;
+		activity.getWindow().set_native_window(Context.this_application.native_window);
 		Slog.i(TAG, "activity.getWindow().native_window >"+activity.getWindow().native_window+"<");
 		return activity;
 	}
@@ -168,7 +168,7 @@ public class Instrumentation {
 				Constructor<? extends Activity> constructor = cls.getConstructor();
 				final Activity activity = constructor.newInstance();
 				activity.intent = intent;
-				activity.getWindow().native_window = Context.this_application.native_window;
+				activity.getWindow().set_native_window(Context.this_application.native_window);
 				runOnMainSync(new Runnable() {
 					@Override
 					public void run() {

src/api-impl/android/view/View.java

@@ -867,7 +867,7 @@ public class View implements Drawable.Callback {
 	private Context context;
 	private Map<Integer,Object> tags = new HashMap<>();
 	private Object tag;
-	int gravity = -1;  // fallback gravity for layout childs
+	int gravity = -1;  // fallback gravity for layout children
 
 	int measuredWidth = 0;
 	int measuredHeight = 0;
@@ -880,6 +880,8 @@ public class View implements Drawable.Callback {
 	private int scrollX = 0;
 	private int scrollY = 0;
 
+	ViewTreeObserver floating_observer = null;
+
 	public long widget; // pointer
 
 	private int oldWidthMeasureSpec = -1;
@@ -1236,8 +1238,17 @@ public class View implements Drawable.Callback {
 
 	public void setSelected(boolean selected) {}
 
+	public native Window native_get_window(long widget);
 	public ViewTreeObserver getViewTreeObserver() {
-		return new ViewTreeObserver();
+		Window window = native_get_window(widget);
+		if (window != null) {
+			if (window.view_tree_observer == null)
+				window.view_tree_observer = new ViewTreeObserver(window);
+			return window.view_tree_observer;
+		} else {
+			floating_observer = new ViewTreeObserver(null);
+			return floating_observer;
+		}
 	}
 
 	protected void onFinishInflate() {}
@@ -1961,8 +1972,24 @@ public class View implements Drawable.Callback {
 		keepScreenOn = screenOn;
 	}
 
-	protected void onAttachedToWindow() {}
+	protected void onAttachedToWindow() {
-	protected void onDetachedFromWindow() {}
+		if (onAttachStateChangeListener != null) {
+			onAttachStateChangeListener.onViewAttachedToWindow(this);
+		}
+		if (keepScreenOn)
+			native_keep_screen_on(widget, true);
+		if(floating_observer != null) {
+			getViewTreeObserver().merge(floating_observer);
+			floating_observer = null;
+		}
+	}
+	protected void onDetachedFromWindow() {
+		if (onAttachStateChangeListener != null) {
+			onAttachStateChangeListener.onViewDetachedFromWindow(this);
+		}
+		if (keepScreenOn)
+			native_keep_screen_on(widget, false);
+	}
 
 	public void setLayerType(int layerType, Paint paint) {}
 
@@ -2274,4 +2301,8 @@ public class View implements Drawable.Callback {
 	public Bitmap getDrawingCache() { return null; }
 
 	public void announceForAccessibility(CharSequence text) {}
+
+	public WindowInsetsController getWindowInsetsController() {
+		return native_get_window(widget).getInsetsController();
+	}
 }

src/api-impl/android/view/ViewTreeObserver.java

@@ -51,6 +51,11 @@ public final class ViewTreeObserver {
 
 	private boolean mAlive = true;
 
+	// accessed from native code
+	private long onGlobalLayout_signal_handle = 0;
+
+	private long window;
+
 	/**
 	 * Interface definition for a callback to be invoked when the view hierarchy is
 	 * attached to and detached from its window.
@@ -297,10 +302,9 @@ public final class ViewTreeObserver {
 		public void onComputeInternalInsets(InternalInsetsInfo inoutInfo);
 	}
 
-	/**
+	ViewTreeObserver(Window window) {
-	 * Creates a new ViewTreeObserver. This constructor should not be called
+		if(window != null)
-	 */
+			this.window = window.native_window;
-	ViewTreeObserver() {
 	}
 
 	/**
@@ -335,7 +339,10 @@ public final class ViewTreeObserver {
 			}
 		}
 
-		if (observer.mOnGlobalLayoutListeners != null) {
+		if (observer.mOnGlobalLayoutListeners != null && observer.mOnGlobalLayoutListeners.size() > 0) {
+			if(mOnGlobalLayoutListeners == null || mOnGlobalLayoutListeners.size() == 0)
+				native_set_have_global_layout_listeners(true);
+
 			if (mOnGlobalLayoutListeners != null) {
 				mOnGlobalLayoutListeners.addAll(observer.mOnGlobalLayoutListeners);
 			} else {
@@ -495,17 +502,11 @@ public final class ViewTreeObserver {
 			mOnGlobalLayoutListeners = new CopyOnWriteArray<OnGlobalLayoutListener>();
 		}
 
+		if (mOnGlobalLayoutListeners.size() == 0) {
+			native_set_have_global_layout_listeners(true);
+		}
+
 		mOnGlobalLayoutListeners.add(listener);
-
-		// hack: many Applications wait for the global layout before doing anything
-		// so we dispatch the event immediately
-		new Handler(Looper.getMainLooper()).post(new Runnable() {
-			@Override
-			public void run() {
-				listener.onGlobalLayout();
-			}
-		});
-
 	}
 
 	/**
@@ -539,6 +540,9 @@ public final class ViewTreeObserver {
 			return;
 		}
 		mOnGlobalLayoutListeners.remove(victim);
+
+		if(mOnGlobalLayoutListeners.size() == 0)
+			native_set_have_global_layout_listeners(false);
 	}
 
 	/**
@@ -754,6 +758,9 @@ public final class ViewTreeObserver {
 	 * @hide
 	 */
 	private void kill() {
+		/* clear any callbacks */
+		if (mOnGlobalLayoutListeners != null && mOnGlobalLayoutListeners.size() > 0)
+			native_set_have_global_layout_listeners(false);
 		mAlive = false;
 	}
 
@@ -1038,4 +1045,6 @@ public final class ViewTreeObserver {
 			getArray().clear();
 		}
 	}
+
+	private native void native_set_have_global_layout_listeners(boolean have_listeners);
 }

src/api-impl/android/view/Window.java

@@ -10,6 +10,8 @@ public class Window {
 	public static final int FEATURE_OPTIONS_PANEL = 0;
 	public static final int FEATURE_NO_TITLE = 1;
 
+	public ViewTreeObserver view_tree_observer = null;
+
 	public static interface Callback {
 		public void onContentChanged();
 
@@ -41,6 +43,11 @@ public class Window {
 		decorView.setId(android.R.id.content);
 	}
 
+	public void set_native_window(long native_window) {
+		this.native_window = native_window;
+		set_jobject(native_window, this);
+	}
+
 	public void addFlags(int flags) {}
 	public void setFlags(int flags, int mask) {}
 	public void clearFlags(int flags) {}
@@ -64,12 +71,6 @@ public class Window {
 		return decorView;
 	}
 
-	public native void set_widget_as_root(long native_window, long widget);
-	private native void set_title(long native_window, String title);
-
-	public native void take_input_queue(long native_window, InputQueue.Callback callback, InputQueue queue);
-	public native void set_layout(long native_window, int width, int height);
-
 	public void takeInputQueue(InputQueue.Callback callback) {
 		take_input_queue(native_window, callback, new InputQueue());
 	}
@@ -161,4 +162,16 @@ public class Window {
 	public void setEnterTransition(Transition transition) {}
 
 	public void setGravity(int gravity) {}
+
+	public void setDecorFitsSystemWindows(boolean fits) {}
+
+	public WindowInsetsController getInsetsController() {
+		return new InsetsController();
+	}
+
+	public native void set_widget_as_root(long native_window, long widget);
+	private native void set_title(long native_window, String title);
+	public native void take_input_queue(long native_window, InputQueue.Callback callback, InputQueue queue);
+	public native void set_layout(long native_window, int width, int height);
+	private static native void set_jobject(long ptr, Window obj);
 }