WindowServer: Add basic menu applet concept

It's now possible to create a little applet window that sits inside the
system's menubar. This is done using the new CreateMenuApplet IPC call.

So far, it's possible to assign a backing store ID, and to invalidate
rects for repaint. There is no way to get the events from inside the
applet just yet.

This will allow us to move the CPU graph and audio thingy to separate
applet processes. :^)

1 files changed, 45 insertions, 0 deletions

diff --git a/Servers/WindowServer/WSMenuManager.cpp b/Servers/WindowServer/WSMenuManager.cpp
index 5be1a6c5a1..7712bedaf6 100644
--- a/Servers/WindowServer/WSMenuManager.cpp
+++ b/Servers/WindowServer/WSMenuManager.cpp
@@ -129,6 +129,12 @@ void WSMenuManager::draw()
 
     auto& audio_bitmap = m_audio_muted ? *m_muted_bitmap : *m_unmuted_bitmap;
     painter.blit(m_audio_rect.location(), audio_bitmap, audio_bitmap.rect());
+
+    for (auto& applet : m_applets) {
+        if (!applet)
+            continue;
+        draw_applet(*applet);
+    }
 }
 
 void WSMenuManager::tick_clock()
@@ -282,3 +288,42 @@ void WSMenuManager::close_bar()
     close_everyone();
     m_bar_open = false;
 }
+
+void WSMenuManager::add_applet(WSMenuApplet& applet)
+{
+    int right_edge_x = m_audio_rect.x() - 4;
+    for (auto& existing_applet : m_applets) {
+        if (existing_applet)
+            right_edge_x = existing_applet->rect_in_menubar().x() - 4;
+    }
+
+    Rect new_applet_rect(right_edge_x - applet.size().width(), 0, applet.size().width(), applet.size().height());
+    Rect dummy_menubar_rect(0, 0, 0, 18);
+    new_applet_rect.center_vertically_within(dummy_menubar_rect);
+
+    applet.set_rect_in_menubar(new_applet_rect);
+    m_applets.append(applet.make_weak_ptr());
+}
+
+void WSMenuManager::remove_applet(WSMenuApplet& applet)
+{
+    m_applets.remove_first_matching([&](auto& entry) {
+        return &applet == entry.ptr();
+    });
+}
+
+void WSMenuManager::draw_applet(const WSMenuApplet& applet)
+{
+    if (!applet.bitmap())
+        return;
+    Painter painter(*window().backing_store());
+    painter.blit(applet.rect_in_menubar().location(), *applet.bitmap(), applet.bitmap()->rect());
+}
+
+void WSMenuManager::invalidate_applet(WSMenuApplet& applet, const Rect& rect)
+{
+    // FIXME: This should only invalidate the applet's own rect, not the whole menubar.
+    (void)rect;
+    draw_applet(applet);
+    window().invalidate();
+}