ANDROID: check for memory allocation errors when resizing the screen

Author: chrisws

src/platform/android/jni/display.cpp

@@ -27,15 +27,15 @@ extern ui::Graphics *graphics;
 Canvas::Canvas() :
   _w(0),
   _h(0),
-  _pixels(NULL),
-  _clip(NULL) {
+  _pixels(nullptr),
+  _clip(nullptr) {
 }
 
 Canvas::~Canvas() {
   delete [] _pixels;
   delete _clip;
-  _pixels = NULL;
-  _clip = NULL;
+  _pixels = nullptr;
+  _clip = nullptr;
 }
 
 bool Canvas::create(int w, int h) {
@@ -108,16 +108,16 @@ void Canvas::setClip(int x, int y, int w, int h) {
     _clip->right = x + w;
     _clip->bottom = y + h;
   } else {
-    _clip = NULL;
+    _clip = nullptr;
   }
 }
 
 //
 // Graphics implementation
 //
 Graphics::Graphics(android_app *app) : ui::Graphics(),
-  _fontBuffer(NULL),
-  _fontBufferB(NULL),
+  _fontBuffer(nullptr),
+  _fontBufferB(nullptr),
   _app(app),
   _w(0),
   _h(0),
@@ -129,8 +129,8 @@ Graphics::~Graphics() {
 
   delete [] _fontBuffer;
   delete [] _fontBufferB;
-  _fontBuffer = NULL;
-  _fontBufferB = NULL;
+  _fontBuffer = nullptr;
+  _fontBufferB = nullptr;
 }
 
 bool Graphics::construct(int fontId) {
@@ -157,16 +157,16 @@ bool Graphics::construct(int fontId) {
 }
 
 void Graphics::redraw() {
-  if (_app->window != NULL && !_paused) {
+  if (_app->window != nullptr && !_paused) {
     ANativeWindow_Buffer buffer;
-    bool locked = ANativeWindow_lock(_app->window, &buffer, NULL) == 0;
+    bool locked = ANativeWindow_lock(_app->window, &buffer, nullptr) == 0;
     if (!locked) {
       trace("Unable to lock window buffer");
     } else {
       if (buffer.format != AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM) {
         ANativeWindow_unlockAndPost(_app->window);
         ANativeWindow_setBuffersGeometry(_app->window, 0, 0, AHARDWAREBUFFER_FORMAT_R8G8B8A8_UNORM);
-        locked = ANativeWindow_lock(_app->window, &buffer, NULL) == 0;
+        locked = ANativeWindow_lock(_app->window, &buffer, nullptr) == 0;
         trace("Restore format %d", locked);
       }
       if (locked) {
@@ -184,11 +184,22 @@ void Graphics::redraw() {
   }
 }
 
-void Graphics::resize() {
-  delete _screen;
-  _screen = new Canvas();
-  _screen->create(_w, _h);
-  _drawTarget = NULL;
+bool Graphics::resize() {
+  bool result;
+  if (_screen == nullptr || _screen->_w != _w || _screen->_h != _h) {
+    Canvas *newScreen = new Canvas();
+    result = newScreen->create(_w, _h);
+    if (result) {
+      delete _screen;
+      _screen = newScreen;
+      _drawTarget = nullptr;
+    } else {
+      trace("Failed to resize canvas");
+    }
+  } else {
+    result = true;
+  }
+  return result;
 }
 
 bool Graphics::loadFonts(int fontId) {

src/platform/android/jni/display.h

@@ -24,7 +24,7 @@ struct Graphics : ui::Graphics {
 
   bool construct(int fontId);
   void redraw();
-  void resize();
+  bool resize();
   void onPaused(bool paused) { _paused=paused; }
   void setSize(int w, int h) { _w = w; _h = h; }
 

src/platform/android/jni/runtime.cpp

@@ -842,8 +842,11 @@ MAEvent Runtime::processEvents(int waitFlag) {
 void Runtime::processEvent(MAEvent &event) {
   switch (event.type) {
   case EVENT_TYPE_SCREEN_CHANGED:
-    _graphics->resize();
-    resize();
+    if (_graphics->resize()) {
+      resize();
+    } else {
+      alert("System error: Failed to resize screen");
+    }
     break;
   case EVENT_TYPE_KEY_PRESSED:
     handleKeyEvent(event);

src/ui/graphics.cpp

@@ -81,9 +81,9 @@ Font::~Font() {
 // Graphics implementation
 //
 Graphics::Graphics() :
-  _screen(NULL),
-  _drawTarget(NULL),
-  _font(NULL) {
+  _screen(nullptr),
+  _drawTarget(nullptr),
+  _font(nullptr) {
   graphics = this;
 }
 
@@ -92,8 +92,8 @@ Graphics::~Graphics() {
 
   FT_Done_FreeType(_fontLibrary);
   delete _screen;
-  graphics = NULL;
-  _screen = NULL;
+  graphics = nullptr;
+  _screen = nullptr;
 }
 
 Font *Graphics::createFont(int style, int size) {
@@ -109,7 +109,7 @@ Font *Graphics::createFont(int style, int size) {
 
 void Graphics::deleteFont(Font *font) {
   if (font == _font) {
-    _font = NULL;
+    _font = nullptr;
   }
   delete font;
 }
@@ -454,7 +454,7 @@ MAHandle Graphics::setDrawTarget(MAHandle maHandle) {
     _drawTarget = (Canvas *)maHandle;
   }
   delete _drawTarget->_clip;
-  _drawTarget->_clip = NULL;
+  _drawTarget->_clip = nullptr;
   return result;
 }