Taskbar: Don't create buttons for modal windows

Since the user can't really do much with windows that are blocked
by a modal window, there is no point in showing multiple buttons.

Services/Taskbar/TaskbarWindow.cpp

@@ -35,6 +35,7 @@
 #include <LibGUI/Frame.h>
 #include <LibGUI/Painter.h>
 #include <LibGUI/Window.h>
+#include <LibGUI/WindowServerConnection.h>
 #include <LibGfx/Palette.h>
 #include <stdio.h>
 
@@ -74,10 +75,6 @@ TaskbarWindow::TaskbarWindow()
 
     m_default_icon = Gfx::Bitmap::load_from_file("/res/icons/16x16/window.png");
 
-    WindowList::the().aid_create_button = [this](auto& identifier) {
-        return create_button(identifier);
-    };
-
     create_quick_launch_bar();
 }
 
@@ -161,6 +158,67 @@ static bool should_include_window(GUI::WindowType window_type, bool is_frameless
     return window_type == GUI::WindowType::Normal && !is_frameless;
 }
 
+void TaskbarWindow::add_window_button(::Window& window, const WindowIdentifier& identifier)
+{
+    if (window.button())
+        return;
+    window.set_button(create_button(identifier));
+    auto* button = window.button();
+    button->on_click = [window = &window, identifier, button](auto) {
+        // We need to look at the button's checked state here to figure
+        // out if the application is active or not. That's because this
+        // button's window may not actually be active when a modal window
+        // is displayed, in which case window->is_active() would return
+        // false because window is the modal window's owner (which is not
+        // active)
+        if (window->is_minimized() || !button->is_checked()) {
+            GUI::WindowServerConnection::the().post_message(Messages::WindowServer::WM_SetActiveWindow(identifier.client_id(), identifier.window_id()));
+        } else {
+            GUI::WindowServerConnection::the().post_message(Messages::WindowServer::WM_SetWindowMinimized(identifier.client_id(), identifier.window_id(), true));
+        }
+    };
+}
+
+void TaskbarWindow::remove_window_button(::Window& window)
+{
+    auto* button = window.button();
+    if (!button)
+        return;
+    window.set_button(nullptr);
+    button->remove_from_parent();
+}
+
+void TaskbarWindow::update_window_button(::Window& window, bool show_as_active)
+{
+    auto* button = window.button();
+    if (!button)
+        return;
+
+    if (window.is_minimized()) {
+        button->set_foreground_color(Color::DarkGray);
+    } else {
+        button->set_foreground_color(Color::Black);
+    }
+    button->set_text(window.title());
+    button->set_checked(show_as_active);
+}
+
+::Window* TaskbarWindow::find_window_owner(::Window& window) const
+{
+    if (!window.is_modal())
+        return &window;
+
+    ::Window* parent = nullptr;
+    auto* current_window = &window;
+    while (current_window) {
+        parent = WindowList::the().find_parent(*current_window);
+        if (!parent || !parent->is_modal())
+            break;
+        current_window = parent;
+    }
+    return parent;
+}
+
 void TaskbarWindow::wm_event(GUI::WMEvent& event)
 {
     WindowIdentifier identifier { event.client_id(), event.window_id() };
@@ -198,7 +256,8 @@ void TaskbarWindow::wm_event(GUI::WMEvent& event)
         if (auto* window = WindowList::the().window(identifier)) {
             auto buffer = SharedBuffer::create_from_shbuf_id(changed_event.icon_buffer_id());
             ASSERT(buffer);
-            window->button()->set_icon(Gfx::Bitmap::create_with_shared_buffer(Gfx::BitmapFormat::RGBA32, *buffer, changed_event.icon_size()));
+            if (window->button())
+                window->button()->set_icon(Gfx::Bitmap::create_with_shared_buffer(Gfx::BitmapFormat::RGBA32, *buffer, changed_event.icon_size()));
         }
         break;
     }
@@ -217,18 +276,27 @@ void TaskbarWindow::wm_event(GUI::WMEvent& event)
         if (!should_include_window(changed_event.window_type(), changed_event.is_frameless()))
             break;
         auto& window = WindowList::the().ensure_window(identifier);
+        window.set_parent_identifier({ changed_event.parent_client_id(), changed_event.parent_window_id() });
+        if (!window.is_modal())
+            add_window_button(window, identifier);
+        else
+            remove_window_button(window);
         window.set_title(changed_event.title());
         window.set_rect(changed_event.rect());
+        window.set_modal(changed_event.is_modal());
         window.set_active(changed_event.is_active());
         window.set_minimized(changed_event.is_minimized());
         window.set_progress(changed_event.progress());
-        if (window.is_minimized()) {
-            window.button()->set_foreground_color(Color::DarkGray);
-        } else {
-            window.button()->set_foreground_color(Color::Black);
+
+        auto* window_owner = find_window_owner(window);
+        if (window_owner == &window) {
+            update_window_button(window, window.is_active());
+        } else if (window_owner) {
+            // check the window owner's button if the modal's window button
+            // would have been checked
+            ASSERT(window.is_modal());
+            update_window_button(*window_owner, window.is_active());
         }
-        window.button()->set_text(changed_event.title());
-        window.button()->set_checked(changed_event.is_active());
         break;
     }
     default:

Services/Taskbar/TaskbarWindow.h

@@ -42,6 +42,10 @@ private:
     void create_quick_launch_bar();
     void on_screen_rect_change(const Gfx::IntRect&);
     NonnullRefPtr<GUI::Button> create_button(const WindowIdentifier&);
+    void add_window_button(::Window&, const WindowIdentifier&);
+    void remove_window_button(::Window&);
+    void update_window_button(::Window&, bool);
+    ::Window* find_window_owner(::Window&) const;
 
     virtual void wm_event(GUI::WMEvent&) override;
 

Services/Taskbar/WindowIdentifier.h

@@ -30,6 +30,7 @@
 
 class WindowIdentifier {
 public:
+    WindowIdentifier() = default;
     WindowIdentifier(int client_id, int window_id)
         : m_client_id(client_id)
         , m_window_id(window_id)
@@ -44,6 +45,11 @@ public:
         return m_client_id == other.m_client_id && m_window_id == other.m_window_id;
     }
 
+    bool is_valid() const
+    {
+        return m_client_id != -1 && m_window_id != -1;
+    }
+
 private:
     int m_client_id { -1 };
     int m_window_id { -1 };

Services/Taskbar/WindowList.cpp

@@ -25,7 +25,6 @@
  */
 
 #include "WindowList.h"
-#include <LibGUI/WindowServerConnection.h>
 
 WindowList& WindowList::the()
 {
@@ -35,6 +34,19 @@ WindowList& WindowList::the()
     return *s_the;
 }
 
+Window* WindowList::find_parent(const Window& window)
+{
+   if (!window.parent_identifier().is_valid())
+       return nullptr;
+   for (auto& it : m_windows)
+   {
+       auto& w = *it.value;
+       if (w.identifier() == window.parent_identifier())
+           return &w;
+   }
+   return nullptr;
+}
+
 Window* WindowList::window(const WindowIdentifier& identifier)
 {
     auto it = m_windows.find(identifier);
@@ -49,14 +61,6 @@ Window& WindowList::ensure_window(const WindowIdentifier& identifier)
     if (it != m_windows.end())
         return *it->value;
     auto window = make<Window>(identifier);
-    window->set_button(aid_create_button(identifier));
-    window->button()->on_click = [window = window.ptr(), identifier](auto) {
-        if (window->is_minimized() || !window->is_active()) {
-            GUI::WindowServerConnection::the().post_message(Messages::WindowServer::WM_SetActiveWindow(identifier.client_id(), identifier.window_id()));
-        } else {
-            GUI::WindowServerConnection::the().post_message(Messages::WindowServer::WM_SetWindowMinimized(identifier.client_id(), identifier.window_id(), true));
-        }
-    };
     auto& window_ref = *window;
     m_windows.set(identifier, move(window));
     return window_ref;

Services/Taskbar/WindowList.h

@@ -45,7 +45,10 @@ public:
             m_button->remove_from_parent();
     }
 
-    WindowIdentifier identifier() const { return m_identifier; }
+    const WindowIdentifier& identifier() const { return m_identifier; }
+
+    void set_parent_identifier(const WindowIdentifier& parent_identifier) { m_parent_identifier = parent_identifier; }
+    const WindowIdentifier& parent_identifier() const { return m_parent_identifier; }
 
     String title() const { return m_title; }
     void set_title(const String& title) { m_title = title; }
@@ -62,12 +65,16 @@ public:
     void set_minimized(bool minimized) { m_minimized = minimized; }
     bool is_minimized() const { return m_minimized; }
 
+    void set_modal(bool modal) { m_modal = modal; }
+    bool is_modal() const { return m_modal; }
+
     void set_progress(int progress)
     {
         if (m_progress == progress)
             return;
         m_progress = progress;
-        m_button->update();
+        if (m_button)
+            m_button->update();
     }
 
     int progress() const { return m_progress; }
@@ -76,12 +83,14 @@ public:
 
 private:
     WindowIdentifier m_identifier;
+    WindowIdentifier m_parent_identifier;
     String m_title;
     Gfx::IntRect m_rect;
     RefPtr<GUI::Button> m_button;
     RefPtr<Gfx::Bitmap> m_icon;
     bool m_active { false };
     bool m_minimized { false };
+    bool m_modal { false };
     int m_progress { -1 };
 };
 
@@ -96,12 +105,11 @@ public:
             callback(*it.value);
     }
 
+    Window* find_parent(const Window&);
     Window* window(const WindowIdentifier&);
     Window& ensure_window(const WindowIdentifier&);
     void remove_window(const WindowIdentifier&);
 
-    Function<NonnullRefPtr<GUI::Button>(const WindowIdentifier&)> aid_create_button;
-
 private:
     HashMap<WindowIdentifier, NonnullOwnPtr<Window>> m_windows;
 };