fixed some issues with the software renderer when surfaces are made current.

there was several issues:
- when a surface was made non-current, the last frame wasn't shown and the buffer could stay locked
- when a surface was made current the 2nd time, it would not dequeue a new buffer

now, queue/dequeue are done when the surface is made current.

for this to work, a new query() hook had to be added on android_native_window_t, it allows to retrieve some attributes of a window (currently only width and height).

libs/ui/FramebufferNativeWindow.cpp

@@ -124,6 +124,7 @@ FramebufferNativeWindow::FramebufferNativeWindow()
     android_native_window_t::dequeueBuffer = dequeueBuffer;
     android_native_window_t::lockBuffer = lockBuffer;
     android_native_window_t::queueBuffer = queueBuffer;
+    android_native_window_t::query = query;
 }
 
 FramebufferNativeWindow::~FramebufferNativeWindow() {
@@ -198,6 +199,23 @@ int FramebufferNativeWindow::queueBuffer(android_native_window_t* window,
     return res;
 }
 
+int FramebufferNativeWindow::query(android_native_window_t* window,
+        int what, int* value) 
+{
+    FramebufferNativeWindow* self = getSelf(window);
+    Mutex::Autolock _l(self->mutex);
+    framebuffer_device_t* fb = self->fbDev;
+    switch (what) {
+        case NATIVE_WINDOW_WIDTH:
+            *value = fb->width;
+            return NO_ERROR;
+        case NATIVE_WINDOW_HEIGHT:
+            *value = fb->height;
+            return NO_ERROR;
+    }
+    return BAD_VALUE;
+}
+
 // ----------------------------------------------------------------------------
 }; // namespace android
 // ----------------------------------------------------------------------------