Android: Fixed an OpenGL crash that would occur due to failing to get a pointer to the native window

modules/juce_opengl/native/juce_OpenGL_android.h

@@ -88,7 +88,7 @@ public:
     }
 
     //==============================================================================
-    void initialiseOnRenderThread (OpenGLContext& aContext)
+    bool initialiseOnRenderThread (OpenGLContext& aContext)
     {
         jassert (hasInitialised);
 
@@ -100,9 +100,25 @@ public:
         // get a pointer to the native window
         ANativeWindow* window = nullptr;
         if (jobject jSurface = env->CallObjectMethod (surfaceView.get(), NativeSurfaceView.getNativeSurface))
-            window = ANativeWindow_fromSurface (env, jSurface);
+        {
+            window = ANativeWindow_fromSurface(env, jSurface);
 
-        jassert (window != nullptr);
+            // if we didn't succeed the first time, wait 25ms and try again
+            if (window == nullptr)
+            {
+                Thread::sleep (25);
+                window = ANativeWindow_fromSurface (env, jSurface);
+            }
+        }
+
+        if (window == nullptr)
+        {
+            // failed to get a pointer to the native window after second try so
+            // bail out
+            jassertfalse;
+
+            return false;
+        }
 
         // create the surface
         surface = eglCreateWindowSurface(display, config, window, 0);
@@ -116,6 +132,8 @@ public:
         jassert (context != EGL_NO_CONTEXT);
 
         juceContext = &aContext;
+
+        return true;
     }
 
     void shutdownOnRenderThread()

modules/juce_opengl/native/juce_OpenGL_ios.h

@@ -113,7 +113,7 @@ public:
         [view release];
     }
 
-    void initialiseOnRenderThread (OpenGLContext&) {}
+    bool initialiseOnRenderThread (OpenGLContext&)    { return true; }
 
     void shutdownOnRenderThread()
     {

modules/juce_opengl/native/juce_OpenGL_linux_X11.h

@@ -142,12 +142,14 @@ public:
         XWindowSystem::getInstance()->displayUnref();
     }
 
-    void initialiseOnRenderThread (OpenGLContext& c)
+    bool initialiseOnRenderThread (OpenGLContext& c)
     {
         ScopedXLock xlock (display);
         renderContext = glXCreateContext (display, bestVisual, (GLXContext) contextToShareWith, GL_TRUE);
         c.makeActive();
         context = &c;
+
+        return true;
     }
 
     void shutdownOnRenderThread()

modules/juce_opengl/native/juce_OpenGL_osx.h

@@ -111,12 +111,12 @@ public:
         }
     }
 
-    void initialiseOnRenderThread (OpenGLContext&) {}
-    void shutdownOnRenderThread()               { deactivateCurrentContext(); }
+    bool initialiseOnRenderThread (OpenGLContext&)    { return true; }
+    void shutdownOnRenderThread()                     { deactivateCurrentContext(); }
 
-    bool createdOk() const noexcept             { return getRawContext() != nullptr; }
-    void* getRawContext() const noexcept        { return static_cast<void*> (renderContext); }
-    GLuint getFrameBufferID() const noexcept    { return 0; }
+    bool createdOk() const noexcept                   { return getRawContext() != nullptr; }
+    void* getRawContext() const noexcept              { return static_cast<void*> (renderContext); }
+    GLuint getFrameBufferID() const noexcept          { return 0; }
 
     bool makeActive() const noexcept
     {

modules/juce_opengl/native/juce_OpenGL_win32.h

@@ -89,7 +89,12 @@ public:
         releaseDC();
     }
 
-    void initialiseOnRenderThread (OpenGLContext& c) { context = &c; }
+    bool initialiseOnRenderThread (OpenGLContext& c)
+    {
+        context = &c;
+        return true;
+    }
+
     void shutdownOnRenderThread()           { deactivateCurrentContext(); context = nullptr; }
 
     static void deactivateCurrentContext()  { wglMakeCurrent (0, 0); }

modules/juce_opengl/opengl/juce_OpenGLContext.cpp

@@ -438,7 +438,13 @@ public:
             } while (! mmLock.retryLock());
         }
 
-        initialiseOnThread();
+        if (! initialiseOnThread())
+        {
+            hasInitialised = false;
+
+            return ThreadPoolJob::jobHasFinished;
+        }
+
         hasInitialised = true;
 
         while (! shouldExit())
@@ -468,7 +474,7 @@ public:
         return ThreadPoolJob::jobHasFinished;
     }
 
-    void initialiseOnThread()
+    bool initialiseOnThread()
     {
         // On android, this can get called twice, so drop any previous state..
         associatedObjectNames.clear();
@@ -476,7 +482,9 @@ public:
         cachedImageFrameBuffer.release();
 
         context.makeActive();
-        nativeContext->initialiseOnRenderThread (context);
+
+        if (! nativeContext->initialiseOnRenderThread (context))
+            return false;
 
        #if JUCE_ANDROID
         // On android the context may be created in initialiseOnRenderThread
@@ -506,6 +514,8 @@ public:
 
         if (context.renderer != nullptr)
             context.renderer->newOpenGLContextCreated();
+
+        return true;
     }
 
     void shutdownOnThread()