From 68c0e69f0ae3e7a803e8ed2f292cd0a6e165ccb6 Mon Sep 17 00:00:00 2001
From: Sylvain Becker <sylvain.becker@gmail.com>
Date: Wed, 9 Jan 2019 22:41:52 +0100
Subject: [PATCH] Android: native_window validity is guaranteed between
 surfaceCreated and Destroyed

It's currently still available after surfaceDestroyed().
And available (but invalid) between surfaceCreated() and surfaceChanged().

Which means ANativewindow_getWidth/Height/Format() fail in those cases.

https://developer.android.com/reference/android/view/SurfaceHolder.html#getSurface()
---
 .../main/java/org/libsdl/app/SDLActivity.java |  2 ++
 src/core/android/SDL_android.c                | 33 +++++++++++++++----
 2 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/android-project/app/src/main/java/org/libsdl/app/SDLActivity.java b/android-project/app/src/main/java/org/libsdl/app/SDLActivity.java
index ac8515d01fc3d..09cafc55790b6 100644
--- a/android-project/app/src/main/java/org/libsdl/app/SDLActivity.java
+++ b/android-project/app/src/main/java/org/libsdl/app/SDLActivity.java
@@ -737,6 +737,7 @@ public static native void onNativeTouch(int touchDevId, int pointerFingerId,
                                             float y, float p);
     public static native void onNativeAccel(float x, float y, float z);
     public static native void onNativeClipboardChanged();
+    public static native void onNativeSurfaceCreated();
     public static native void onNativeSurfaceChanged();
     public static native void onNativeSurfaceDestroyed();
     public static native String nativeGetHint(String name);
@@ -1574,6 +1575,7 @@ public Surface getNativeSurface() {
     @Override
     public void surfaceCreated(SurfaceHolder holder) {
         Log.v("SDL", "surfaceCreated()");
+        SDLActivity.onNativeSurfaceCreated();
     }
 
     // Called when we lose the surface
diff --git a/src/core/android/SDL_android.c b/src/core/android/SDL_android.c
index 7de6b4b1ff81c..8613d45655d2c 100644
--- a/src/core/android/SDL_android.c
+++ b/src/core/android/SDL_android.c
@@ -83,6 +83,9 @@ JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(onNativeResize)(
         jint surfaceWidth, jint surfaceHeight,
         jint deviceWidth, jint deviceHeight, jint format, jfloat rate);
 
+JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(onNativeSurfaceCreated)(
+        JNIEnv *env, jclass jcls);
+
 JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(onNativeSurfaceChanged)(
         JNIEnv *env, jclass jcls);
 
@@ -661,8 +664,25 @@ JNIEXPORT jint JNICALL SDL_JAVA_CONTROLLER_INTERFACE(nativeRemoveHaptic)(
     return Android_RemoveHaptic(device_id);
 }
 
+/* Called from surfaceCreated() */
+JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(onNativeSurfaceCreated)(JNIEnv *env, jclass jcls)
+{
+    SDL_LockMutex(Android_ActivityMutex);
+
+    if (Android_Window && Android_Window->driverdata)
+    {
+        SDL_WindowData *data = (SDL_WindowData *) Android_Window->driverdata;
+
+        data->native_window = Android_JNI_GetNativeWindow();
+        if (data->native_window == NULL) {
+            SDL_SetError("Could not fetch native window from UI thread");
+        }
+    }
+
+    SDL_UnlockMutex(Android_ActivityMutex);
+}
 
-/* Surface Created */
+/* Called from surfaceChanged() */
 JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(onNativeSurfaceChanged)(JNIEnv *env, jclass jcls)
 {
     SDL_LockMutex(Android_ActivityMutex);
@@ -674,10 +694,6 @@ JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(onNativeSurfaceChanged)(JNIEnv *env, j
 
         /* If the surface has been previously destroyed by onNativeSurfaceDestroyed, recreate it here */
         if (data->egl_surface == EGL_NO_SURFACE) {
-            if (data->native_window) {
-                ANativeWindow_release(data->native_window);
-            }
-            data->native_window = Android_JNI_GetNativeWindow();
             data->egl_surface = SDL_EGL_CreateSurface(_this, (NativeWindowType) data->native_window);
         }
 
@@ -687,7 +703,7 @@ JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(onNativeSurfaceChanged)(JNIEnv *env, j
     SDL_UnlockMutex(Android_ActivityMutex);
 }
 
-/* Surface Destroyed */
+/* Called from surfaceDestroyed() */
 JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(onNativeSurfaceDestroyed)(JNIEnv *env, jclass jcls)
 {
     SDL_LockMutex(Android_ActivityMutex);
@@ -708,6 +724,11 @@ JNIEXPORT void JNICALL SDL_JAVA_INTERFACE(onNativeSurfaceDestroyed)(JNIEnv *env,
             data->egl_surface = EGL_NO_SURFACE;
         }
 
+        if (data->native_window) {
+            ANativeWindow_release(data->native_window);
+        }
+        data->native_window = NULL;
+
         /* GL Context handling is done in the event loop because this function is run from the Java thread */
     }