WindowServer: Return richer result when changing resolutions

Now we return a boolean value from set_resolution() in the Compositor
and Screen class. Also, the WindowServer IPC now returns a richer result
after changing the resolution, which can be used in clients later.

Servers/WindowServer/ClientConnection.cpp

@@ -316,8 +316,7 @@ OwnPtr<Messages::WindowServer::GetWallpaperResponse> ClientConnection::handle(co
 
 OwnPtr<Messages::WindowServer::SetResolutionResponse> ClientConnection::handle(const Messages::WindowServer::SetResolution& message)
 {
-    WindowManager::the().set_resolution(message.resolution().width(), message.resolution().height());
-    return make<Messages::WindowServer::SetResolutionResponse>();
+    return make<Messages::WindowServer::SetResolutionResponse>(WindowManager::the().set_resolution(message.resolution().width(), message.resolution().height()), WindowManager::the().resolution());
 }
 
 OwnPtr<Messages::WindowServer::SetWindowTitleResponse> ClientConnection::handle(const Messages::WindowServer::SetWindowTitle& message)

Servers/WindowServer/Compositor.cpp

@@ -397,17 +397,18 @@ void Compositor::run_animations()
     });
 }
 
-void Compositor::set_resolution(int desired_width, int desired_height)
+bool Compositor::set_resolution(int desired_width, int desired_height)
 {
     auto screen_rect = Screen::the().rect();
     if (screen_rect.width() == desired_width && screen_rect.height() == desired_height)
-        return;
+        return true;
 
     // Make sure it's impossible to set an invalid resolution
     ASSERT(desired_width >= 640 && desired_height >= 480);
-    Screen::the().set_resolution(desired_width, desired_height);
+    bool success = Screen::the().set_resolution(desired_width, desired_height);
     init_bitmaps();
     compose();
+    return success;
 }
 
 Gfx::Rect Compositor::current_cursor_rect() const

Servers/WindowServer/Compositor.h

@@ -53,7 +53,7 @@ public:
     void invalidate();
     void invalidate(const Gfx::Rect&);
 
-    void set_resolution(int desired_width, int desired_height);
+    bool set_resolution(int desired_width, int desired_height);
 
     bool set_wallpaper(const String& path, Function<void(bool)>&& callback);
     String wallpaper_path() const { return m_wallpaper_path; }

Servers/WindowServer/Screen.cpp

@@ -68,12 +68,23 @@ Screen::~Screen()
 {
 }
 
-void Screen::set_resolution(int width, int height)
+bool Screen::set_resolution(int width, int height)
 {
     FBResolution resolution { 0, (int)width, (int)height };
     int rc = fb_set_resolution(m_framebuffer_fd, &resolution);
-    ASSERT(rc == 0);
+#ifdef WSSCREEN_DEBUG
+    dbg() << "fb_set_resolution() - return code " << rc;
+#endif
+    if (rc == 0) {
         on_change_resolution(resolution.pitch, resolution.width, resolution.height);
+        return true;
+    }
+    if (rc == -1) {
+        dbg() << "Invalid resolution " << width << "x" << height;
+        on_change_resolution(resolution.pitch, resolution.width, resolution.height);
+        return false;
+    }
+    ASSERT_NOT_REACHED();
 }
 
 void Screen::on_change_resolution(int pitch, int width, int height)

Servers/WindowServer/Screen.h

@@ -40,7 +40,7 @@ public:
     Screen(unsigned width, unsigned height);
     ~Screen();
 
-    void set_resolution(int width, int height);
+    bool set_resolution(int width, int height);
     bool can_set_buffer() { return m_can_set_buffer; }
     void set_buffer(int index);
 

Servers/WindowServer/WindowManager.cpp

@@ -106,9 +106,9 @@ void WindowManager::reload_config(bool set_screen)
 
     m_double_click_speed = m_wm_config->read_num_entry("Input", "DoubleClickSpeed", 250);
 
-    if (set_screen)
-        set_resolution(m_wm_config->read_num_entry("Screen", "Width", 1920),
-            m_wm_config->read_num_entry("Screen", "Height", 1080));
+    if (set_screen) {
+        set_resolution(m_wm_config->read_num_entry("Screen", "Width", 1920), m_wm_config->read_num_entry("Screen", "Height", 1080));
+    }
 
     m_arrow_cursor = get_cursor("Arrow", { 2, 2 });
     m_hand_cursor = get_cursor("Hand", { 8, 4 });
@@ -132,19 +132,32 @@ const Gfx::Font& WindowManager::window_title_font() const
     return Gfx::Font::default_bold_font();
 }
 
-void WindowManager::set_resolution(int width, int height)
+bool WindowManager::set_resolution(int width, int height)
 {
-    Compositor::the().set_resolution(width, height);
+    bool success = Compositor::the().set_resolution(width, height);
     MenuManager::the().set_needs_window_resize();
     ClientConnection::for_each_client([&](ClientConnection& client) {
         client.notify_about_new_screen_rect(Screen::the().rect());
     });
     if (m_wm_config) {
+        if (success) {
             dbg() << "Saving resolution: " << Gfx::Size(width, height) << " to config file at " << m_wm_config->file_name();
             m_wm_config->write_num_entry("Screen", "Width", width);
             m_wm_config->write_num_entry("Screen", "Height", height);
             m_wm_config->sync();
+        } else {
+            dbg() << "Saving fallback resolution: " << resolution() << " to config file at " << m_wm_config->file_name();
+            m_wm_config->write_num_entry("Screen", "Width", resolution().width());
+            m_wm_config->write_num_entry("Screen", "Height", resolution().height());
+            m_wm_config->sync();
         }
+    }
+    return success;
+}
+
+Gfx::Size WindowManager::resolution() const
+{
+    return Screen::the().size();
 }
 
 void WindowManager::add_window(Window& window)

Servers/WindowServer/WindowManager.h

@@ -141,7 +141,8 @@ public:
     const Gfx::Font& font() const;
     const Gfx::Font& window_title_font() const;
 
-    void set_resolution(int width, int height);
+    bool set_resolution(int width, int height);
+    Gfx::Size resolution() const;
 
     void set_active_window(Window*);
     void set_hovered_button(Button*);

Servers/WindowServer/WindowServer.ipc

@@ -74,7 +74,7 @@ endpoint WindowServer = 2
     DismissMenu(i32 menu_id) => ()
 
     AsyncSetWallpaper(String path) =|
-    SetResolution(Gfx::Size resolution) => ()
+    SetResolution(Gfx::Size resolution) => (bool success, Gfx::Size resolution)
     SetWindowIconBitmap(i32 window_id, i32 icon_buffer_id, Gfx::Size icon_size) => ()
 
     GetWallpaper() => (String path)