Merge f9d12435e9 into 31381371e8

src/Magnum/Platform/AndroidApplication.cpp

@@ -121,15 +121,17 @@ bool AndroidApplication::tryCreate(const Configuration& configuration, const GLC
         return false;
     }
 
+    _glConfiguration = glConfiguration;
+
     /* Choose config */
     const EGLint configAttributes[] = {
         EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
-        EGL_RED_SIZE, glConfiguration.colorBufferSize().r(),
-        EGL_GREEN_SIZE, glConfiguration.colorBufferSize().g(),
-        EGL_BLUE_SIZE, glConfiguration.colorBufferSize().b(),
-        EGL_ALPHA_SIZE, glConfiguration.colorBufferSize().a(),
-        EGL_DEPTH_SIZE, glConfiguration.depthBufferSize(),
-        EGL_STENCIL_SIZE, glConfiguration.stencilBufferSize(),
+        EGL_RED_SIZE, _glConfiguration.colorBufferSize().r(),
+        EGL_GREEN_SIZE, _glConfiguration.colorBufferSize().g(),
+        EGL_BLUE_SIZE, _glConfiguration.colorBufferSize().b(),
+        EGL_ALPHA_SIZE, _glConfiguration.colorBufferSize().a(),
+        EGL_DEPTH_SIZE, _glConfiguration.depthBufferSize(),
+        EGL_STENCIL_SIZE, _glConfiguration.stencilBufferSize(),
         EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
         EGL_NONE
     };
@@ -177,6 +179,71 @@ bool AndroidApplication::tryCreate(const Configuration& configuration, const GLC
     return _context->tryCreate(glConfiguration);
 }
 
+bool AndroidApplication::reactivateContext() {
+    /* Choose config */
+    const EGLint configAttributes[] = {
+        EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
+        EGL_RED_SIZE, _glConfiguration.colorBufferSize().r(),
+        EGL_GREEN_SIZE, _glConfiguration.colorBufferSize().g(),
+        EGL_BLUE_SIZE, _glConfiguration.colorBufferSize().b(),
+        EGL_ALPHA_SIZE, _glConfiguration.colorBufferSize().a(),
+        EGL_DEPTH_SIZE, _glConfiguration.depthBufferSize(),
+        EGL_STENCIL_SIZE, _glConfiguration.stencilBufferSize(),
+        EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
+        EGL_NONE
+    };
+    EGLint configCount;
+    EGLConfig config;
+    if (!eglChooseConfig(_display, configAttributes, &config, 1, &configCount)) {
+        Error() << "Platform::AndroidApplication::tryCreate(): cannot choose EGL config:"
+            << Implementation::eglErrorString(eglGetError());
+        return false;
+    }
+
+    /* Resize native window and match it to the selected format */
+    EGLint format;
+    CORRADE_INTERNAL_ASSERT_OUTPUT(eglGetConfigAttrib(_display, config, EGL_NATIVE_VISUAL_ID, &format));
+    ANativeWindow_setBuffersGeometry(_state->window,
+        configuration.size().isZero() ? 0 : configuration.size().x(),
+        configuration.size().isZero() ? 0 : configuration.size().y(), format);
+
+    /* Create surface and context */
+    if (!(_surface = eglCreateWindowSurface(_display, config, _state->window, nullptr))) {
+        Error() << "Platform::AndroidApplication::tryCreate(): cannot create EGL window surface:"
+            << Implementation::eglErrorString(eglGetError());
+        return false;
+    }
+
+    /* Make the context current */
+    CORRADE_INTERNAL_ASSERT_OUTPUT(eglMakeCurrent(_display, _surface, _surface, _glContext));
+    return true;
+}
+
+void AndroidApplication::pauseContext() {
+    /* Pause the context current */
+    CORRADE_INTERNAL_ASSERT_OUTPUT(eglMakeCurrent(_display, nullptr, nullptr, nullptr));
+
+    _application_has_valid_surface = false;
+}
+
+void AndroidApplication::pauseApplication()
+{
+    pauseContext();
+}
+
+void AndroidApplication::resumeApplication()
+{
+    reactivateContext();
+}
+
+bool AndroidApplication::hasValidSurface() {
+    return _application_has_valid_surface;
+}
+
+bool AndroidApplication::hasFocus() {
+    return _application_has_focus;
+}
+
 Vector2i AndroidApplication::framebufferSize() const {
     return {ANativeWindow_getWidth(_state->window),
             ANativeWindow_getHeight(_state->window)};
@@ -215,18 +282,30 @@ void AndroidApplication::commandEvent(android_app* state, int32_t cmd) {
             /* Create the application */
             if(!data.instance) {
                 data.instance = data.instancer(state);
-                data.instance->drawEvent();
             }
+            else {
+                data.instance->resumeApplication();
+            }
+            data.instance->drawEvent();
+            data.instance->_application_has_valid_surface = true;
             break;
 
         case APP_CMD_TERM_WINDOW:
-            /* Destroy the application */
-            data.instance.reset();
+            /* This can occur if: the application is destroyed, or just sent to the background */
+            if (data.instance) {
+                data.instance->pauseApplication();
+            }
             break;
 
         case APP_CMD_GAINED_FOCUS:
+            if (data.instance) {
+                data.instance->_application_has_focus = true;
+            }
+            break;
         case APP_CMD_LOST_FOCUS:
-            /** @todo Make use of these */
+            if (data.instance) {
+                data.instance->_application_has_focus = false;
+            }
             break;
 
         case APP_CMD_CONFIG_CHANGED: {

src/Magnum/Platform/AndroidApplication.h

@@ -346,6 +346,51 @@ class AndroidApplication {
 
         /** @{ @name Screen handling */
 
+        /**
+         * @brief Recreate the OpenGL context
+         *
+         * returns @cpp false @ce if the context cannot be created,
+         * @cpp true @ce otherwise.
+         */
+        bool reactivateContext();
+
+        /**
+         * @brief Pause the OpenGL context
+         * 
+         * 
+         */
+        void pauseContext();
+
+        /**
+         * @brief Pause the Application
+         *
+         * Called when the application is attempted to be terminated or sent to the background
+         */
+        virtual void pauseApplication();
+
+        /**
+         * @brief Resume the Application
+         *
+         * Called when the application comes back to the foreground
+         */
+        virtual void resumeApplication();
+
+        /**
+         * @brief OpenGL surface useability
+         *
+         * returns @cpp false @ce if the surface is not available for rendering
+         * @cpp true @ce otherwise.
+         */
+        bool hasValidSurface();
+
+        /**
+         * @brief Application focus
+         *
+         * returns @cpp false @ce if the application is not focused.
+         * @cpp true @ce otherwise.
+         */
+        bool hasFocus();
+
     public:
         /**
          * @brief Window size
@@ -564,6 +609,11 @@ class AndroidApplication {
         EGLSurface _surface;
         EGLContext _glContext;
 
+        GLConfiguration _glConfiguration;
+
+        bool _application_has_valid_surface = false;
+        bool _application_has_focus = false;
+
         /* We have no way to query previous pointer positions, so we have to
            maintain them like this. For pointers capable of hover (mouse, pen)
            the _previousHoverPointerPosition is used, NaN signalling that the