Layout panels on top of their launcher icons

ash/wm/panel_layout_manager.cc

Index: ash/wm/panel_layout_manager.cc
diff --git a/ash/wm/panel_layout_manager.cc b/ash/wm/panel_layout_manager.cc
index d793428d12e41b278e119e66eaea1f9dc6ce21d2..54f20bb9209681829f12ce39b4a9cddf8c804674 100644
--- a/ash/wm/panel_layout_manager.cc
+++ b/ash/wm/panel_layout_manager.cc
@@ -36,11 +36,15 @@ namespace internal {
 PanelLayoutManager::PanelLayoutManager(aura::Window* panel_container)
     : panel_container_(panel_container),
       in_layout_(false),
-      dragged_panel_(NULL) {
+      dragged_panel_(NULL),
+      ALLOW_THIS_IN_INITIALIZER_LIST(launcher_icons_observer_(this)){
   DCHECK(panel_container);
 }
 
 PanelLayoutManager::~PanelLayoutManager() {
+  ash::Launcher* launcher = ash::Shell::GetInstance()->launcher();
+  if (launcher != NULL)
+    launcher->RemoveIconsObserver(&launcher_icons_observer_);
 }
 
 void PanelLayoutManager::StartDragging(aura::Window* panel) {
@@ -55,6 +59,10 @@ void PanelLayoutManager::FinishDragging() {
   Relayout();
 }
 
+void PanelLayoutManager::SetLauncher(ash::Launcher* launcher) {
+  launcher->AddIconsObserver(&launcher_icons_observer_);
+}
+
 void PanelLayoutManager::ToggleMinimize(aura::Window* panel) {
   DCHECK(panel->parent() == panel_container_);
   if (panel->GetProperty(aura::client::kShowStateKey) ==
@@ -148,44 +156,51 @@ void PanelLayoutManager::SetChildBounds(aura::Window* child,
 ////////////////////////////////////////////////////////////////////////////////
 // PanelLayoutManager private implementation:
 
+PanelLayoutManager::LauncherIconsObserver::LauncherIconsObserver(
+    PanelLayoutManager* layout_manager)
+    : layout_manager_(layout_manager) {
+}
+
+void PanelLayoutManager::LauncherIconsObserver
+    ::OnLauncherIconPositionsChanged() {
+  layout_manager_->Relayout();
+}
+
 // This is a rough outline of a simple panel layout manager.
 void PanelLayoutManager::Relayout() {
   if (in_layout_)
     return;
   AutoReset<bool> auto_reset_in_layout(&in_layout_, true);
 
-  // Panels are currently laid out just above the launcher (if it exists),
-  // otherwise at the bottom of the root window.
-  int right, bottom;
   ash::Shell* shell = ash::Shell::GetInstance();
-  if (shell->launcher() && shell->launcher()->widget()->IsVisible()) {
-    const gfx::Rect& bounds =
-        shell->launcher()->widget()->GetWindowScreenBounds();
-    right = bounds.width() - 1 - kPanelMarginEdge;
-    bottom = bounds.y() - 1;
-  } else {
-    const gfx::Rect& bounds = panel_container_->GetRootWindow()->bounds();
-    right = bounds.width() - 1 - kPanelMarginEdge;
-    bottom = bounds.bottom() - 1;
-  }
 
-  // Layout the panel windows right to left.
   for (PanelList::iterator iter = panel_windows_.begin();
        iter != panel_windows_.end(); ++iter) {
     aura::Window* panel_win = *iter;
+    gfx::Rect icon_rect =
+        shell->launcher()->GetScreenBoundsOfItemIconForWindow(panel_win);
+
+    if (icon_rect.width() == 0 && icon_rect.height() == 0)

[stevenjb, 2012/04/03 20:59:28]

I believe this happens when the icon is not visible in the Launcher, e.g. it is
in overflow. For now, I think we should hide the panel if that happens. At
minimum we should comment here that we are explicitly doing nothing in that
case.

[Dmitry Lomov (no reviews), 2012/04/03 21:18:23]

Right, and used does not get any notification on incoming chat. I do not think
this is a good UX.
I'll add comment.

+      continue;
+
+    gfx::Point icon_origin = icon_rect.origin();
+    aura::Window::ConvertPointToWindow(panel_container_->GetRootWindow(),
+                                       panel_container_, &icon_origin);

[stevenjb, 2012/04/03 20:59:28]

icon_origin only appears to be needed in the if block below? We should move this
to inside the if().

[Dmitry Lomov (no reviews), 2012/04/03 21:18:23]

You are right.

+
     if (!panel_win->IsVisible())

[stevenjb, 2012/04/03 20:59:28]

We should probably move this early exit up to immediately after line 179? This
doesn't appear to be related to the code immediately above it.

[Dmitry Lomov (no reviews), 2012/04/03 21:18:23]

Right again.

       continue;
-    int x = right - panel_win->bounds().width();
-    int y = bottom - panel_win->bounds().height();
 
     // Do not relayout dragged panel, but pretend it is in place
     if (panel_win != dragged_panel_) {
-      gfx::Rect bounds(x, y,
-                       panel_win->bounds().width(),
-                       panel_win->bounds().height());
+      gfx::Rect current_bounds = panel_win->bounds();
+
+      gfx::Rect bounds(
+          icon_origin.x() + icon_rect.width()/2 - current_bounds.width()/2,
+          icon_origin.y() - current_bounds.height(),
+          current_bounds.width(),
+          current_bounds.height());
       SetChildBoundsDirect(panel_win, bounds);
     }
-    right = x - kPanelMarginMiddle;
   }
 }