diff options
| -rw-r--r-- | Userland/Libraries/LibGUI/Window.cpp | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/Userland/Libraries/LibGUI/Window.cpp b/Userland/Libraries/LibGUI/Window.cpp index e0c7068d30..6945cb230f 100644 --- a/Userland/Libraries/LibGUI/Window.cpp +++ b/Userland/Libraries/LibGUI/Window.cpp @@ -412,9 +412,19 @@ void Window::handle_multi_paint_event(MultiPaintEvent& event) } else if (m_double_buffering_enabled) { bool was_purged = false; bool bitmap_has_memory = m_back_store->bitmap().set_nonvolatile(was_purged); - if (!bitmap_has_memory || was_purged) { - m_back_store = create_backing_store(event.window_size()); - VERIFY(m_back_store); + if (!bitmap_has_memory) { + // We didn't have enough memory to make the bitmap non-volatile! + // Fall back to single-buffered mode for this window. + // FIXME: Once we have a way to listen for system memory pressure notifications, + // it would be cool to transition back into double-buffered mode once + // the coast is clear. + dbgln("Not enough memory to make backing store non-volatile. Falling back to single-buffered mode."); + m_double_buffering_enabled = false; + m_back_store = move(m_front_store); + created_new_backing_store = true; + } else if (was_purged) { + // The backing store bitmap was cleared, but it does have memory. + // Act as if it's a new backing store so the entire window gets repainted. created_new_backing_store = true; } } @@ -1018,9 +1028,15 @@ void Window::notify_state_changed(Badge<WindowServerConnection>, bool minimized, } else { bool was_purged = false; bool bitmap_has_memory = store->bitmap().set_nonvolatile(was_purged); - if (!bitmap_has_memory || was_purged) { + if (!bitmap_has_memory) { + // Not enough memory to make the bitmap non-volatile. Lose the bitmap and schedule an update. + // Let the paint system figure out what to do. store = nullptr; update(); + } else if (was_purged) { + // The bitmap memory was purged by the kernel, but we have all-new zero-filled pages. + // Schedule an update to regenerate the bitmap. + update(); } } } |