Make panel adjust bounds per preferred size change notification on Windows.

chrome/browser/ui/panels/panel_manager.cc

Index: chrome/browser/ui/panels/panel_manager.cc
===================================================================
--- chrome/browser/ui/panels/panel_manager.cc	(revision 95921)
+++ chrome/browser/ui/panels/panel_manager.cc	(working copy)
@@ -16,8 +16,10 @@
 const size_t kInvalidPanelIndex = static_cast<size_t>(-1);
 
 // Minimum width and height of a panel.
-const int kPanelMinWidthPixels = 64;
-const int kPanelMinHeightPixels = 24;
+// Note: The minimum size of a widget (see widget.cc) is fixed to 100x100.
+// TODO(jianli): Need to fix this to support smaller panel.
+const int kPanelMinWidthPixels = 100;
+const int kPanelMinHeightPixels = 100;
 
 // Default width and height of a panel.
 const int kPanelDefaultWidthPixels = 240;
@@ -110,6 +112,7 @@
 
   Panel* panel = new Panel(browser, bounds);
   panels_.push_back(panel);
+  UpdateMaxSizeForAllPanels();
 
   return panel;
 }
@@ -271,6 +274,72 @@
   DelayedRemove();
 }
 
+void PanelManager::OnPreferredWindowSizeChanged(
+    Panel* panel, const gfx::Size& preferred_window_size) {
+  gfx::Rect bounds = panel->GetBounds();
+  int restored_height = panel->GetRestoredHeight();
+
+  // The panel width:
+  // * cannot grow or shrink to go beyond [min_width, max_width]
+  // * cannot grow to take more than the available space and go beyond the left
+  //   of the work area.
+  int new_width = preferred_window_size.width();
+  int max_width = panel->max_size().width();
+  if (new_width > max_width)
+    new_width = max_width;
+  if (new_width - bounds.width() > current_x_)
+    new_width = bounds.width() + current_x_;
+
+  if (new_width > bounds.width() ||
+      (new_width < bounds.width() &&
+        new_width > panel->min_size().width())) {
+    int delta = bounds.width() - new_width;
+    bounds.set_x(bounds.x() + delta);
+    bounds.set_width(new_width);
+
+    // Reposition all the panels on the left.
+    int panel_index = -1;
+    for (int i = 0; i < static_cast<int>(panels_.size()); ++i) {
+      if (panels_[i] == panel) {
+        panel_index = i;
+        break;
+      }
+    }
+    DCHECK(panel_index >= 0);
+    for (int i = static_cast<int>(panels_.size()) -1; i > panel_index;
+         --i) {
+      gfx::Rect this_bounds = panels_[i]->GetBounds();
+      this_bounds.set_x(this_bounds.x() + delta);
+      panels_[i]->SetPanelBounds(this_bounds);
+    }
+  }
+
+  // The panel height:
+  // * cannot grow or shrink to go beyond [min_height, max_height]
+  int new_height = preferred_window_size.height();
+  if (new_height > max_height_)
+    new_height = max_height_;
+
+  if (new_height > restored_height ||
+      (new_height < restored_height &&
+        new_height > panel->min_size().height())) {
+    // If the panel is not expanded, we only need to save the new restored
+    // height.
+    if (panel->expansion_state() == Panel::EXPANDED) {
+      bounds.set_y(bounds.y() - new_height + bounds.height());
+      bounds.set_height(new_height);
+    } else {
+      panel->SetRestoredHeight(new_height);
+    }
+  }
+
+  panel->SetPanelBounds(bounds);
+  current_x_ =
+      panels_.back()->GetBounds().x() - kPanelsHorizontalSpacing;
+
+  UpdateMaxSizeForAllPanels();
+}
+
 bool PanelManager::ShouldBringUpTitleBarForAllMinimizedPanels(
     int mouse_x, int mouse_y) const {
   for (Panels::const_iterator iter = panels_.begin();
@@ -310,6 +379,8 @@
     if (new_bounds != (*iter)->GetBounds())
       (*iter)->SetPanelBounds(new_bounds);
   }
+
+  UpdateMaxSizeForAllPanels();
 }
 
 bool PanelManager::ComputeBoundsForNextPanel(gfx::Rect* bounds,
@@ -356,3 +427,16 @@
        iter != panels_.rend(); ++iter)
     (*iter)->Close();
 }
+
+void PanelManager::UpdateMaxSizeForAllPanels() {
+  for (Panels::const_iterator iter = panels_.begin();
+       iter != panels_.end(); ++iter) {
+    Panel* panel = *iter;
+    // We arrange the panels from right to left on the screen. |current_x_| is
+    // the left-most point that panels occupy to. So we add |current_x_| for all
+    // panels to mean each of them can try to take over this available space.
+    int width_can_grow_to = panel->GetBounds().width() + current_x_;
+    panel->SetMaxSize(
+        gfx::Size(std::min(width_can_grow_to, max_width_), max_height_));
+  }
+}