Fix the problem that notifications and panels overlap.

chrome/browser/notifications/balloon_collection_impl.cc

Index: chrome/browser/notifications/balloon_collection_impl.cc
diff --git a/chrome/browser/notifications/balloon_collection_impl.cc b/chrome/browser/notifications/balloon_collection_impl.cc
index 9d234c222aa41ebe7753061c00b7ec4f1c3bccbc..173c78caba6898a8077e4e7417204a0e0fc3d279 100644
--- a/chrome/browser/notifications/balloon_collection_impl.cc
+++ b/chrome/browser/notifications/balloon_collection_impl.cc
@@ -10,7 +10,13 @@
 #include "chrome/browser/notifications/balloon.h"
 #include "chrome/browser/notifications/balloon_host.h"
 #include "chrome/browser/notifications/notification.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/panels/panel_manager.h"
+#include "chrome/browser/ui/panels/panel.h"
 #include "chrome/browser/ui/window_sizer.h"
+#include "chrome/common/chrome_notification_types.h"
+#include "content/public/browser/notification_registrar.h"
+#include "content/public/browser/notification_service.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/size.h"
 
@@ -27,6 +33,9 @@ const int kMinAllowedBalloonCount = 2;
 // there is a relayout, in milliseconds.
 const int kRepositionDelay = 300;
 
+// The spacing between the balloon and the panel.
+const int kVerticalSpacingBetweenBalloonAndPanel = 5;
+
 }  // namespace
 
 BalloonCollectionImpl::BalloonCollectionImpl()
@@ -35,6 +44,12 @@ BalloonCollectionImpl::BalloonCollectionImpl()
       added_as_message_loop_observer_(false)
 #endif
 {
+  registrar_.Add(this, chrome::NOTIFICATION_PANEL_ADDED,
+                 content::NotificationService::AllSources());
+  registrar_.Add(this, chrome::NOTIFICATION_PANEL_REMOVED,
+                 content::NotificationService::AllSources());
+  registrar_.Add(this, chrome::NOTIFICATION_PANEL_CHANGED_BOUNDS,
+                 content::NotificationService::AllSources());
 
   SetPositionPreference(BalloonCollection::DEFAULT_POSITION);
 }
@@ -153,6 +168,26 @@ const BalloonCollection::Balloons& BalloonCollectionImpl::GetActiveBalloons() {
   return base_.balloons();
 }
 
+void BalloonCollectionImpl::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  gfx::Rect bounds;
+  switch (type) {
+    case chrome::NOTIFICATION_PANEL_CHANGED_BOUNDS:
+      bounds = content::Source<Panel>(source).ptr()->GetBounds();
+      // Fall through.
+    case chrome::NOTIFICATION_PANEL_ADDED:
+    case chrome::NOTIFICATION_PANEL_REMOVED:
+      if (layout_.ComputeOffsetToMoveAbovePanels(bounds))
+        PositionBalloons(true);
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+}
+
 void BalloonCollectionImpl::PositionBalloonsInternal(bool reposition) {
   const Balloons& balloons = base_.balloons();
 
@@ -231,7 +266,9 @@ void BalloonCollectionImpl::HandleMouseMoveEvent() {
 }
 #endif
 
-BalloonCollectionImpl::Layout::Layout() : placement_(INVALID) {
+BalloonCollectionImpl::Layout::Layout()
+    : placement_(INVALID),
+      offset_to_move_above_panels_(0) {
   RefreshSystemMetrics();
 }
 
@@ -245,24 +282,30 @@ void BalloonCollectionImpl::Layout::GetMaxLinearSize(int* max_balloon_size,
 }
 
 gfx::Point BalloonCollectionImpl::Layout::GetLayoutOrigin() const {
+  // For lower-left and lower-right positioning, we need to add an offset
+  // to ensure balloons to stay on top of panels to avoid overlapping.
   int x = 0;
   int y = 0;
   switch (placement_) {
-    case VERTICALLY_FROM_TOP_LEFT:
+    case VERTICALLY_FROM_TOP_LEFT: {
       x = work_area_.x() + HorizontalEdgeMargin();
-      y = work_area_.y() + VerticalEdgeMargin();
+      y = work_area_.y() + VerticalEdgeMargin() + offset_to_move_above_panels_;
       break;
-    case VERTICALLY_FROM_TOP_RIGHT:
+    }
+    case VERTICALLY_FROM_TOP_RIGHT: {
       x = work_area_.right() - HorizontalEdgeMargin();
-      y = work_area_.y() + VerticalEdgeMargin();
+      y = work_area_.y() + VerticalEdgeMargin() + offset_to_move_above_panels_;
       break;
+    }
     case VERTICALLY_FROM_BOTTOM_LEFT:
       x = work_area_.x() + HorizontalEdgeMargin();
-      y = work_area_.bottom() - VerticalEdgeMargin();
+      y = work_area_.bottom() - VerticalEdgeMargin() -
+          offset_to_move_above_panels_;
       break;
     case VERTICALLY_FROM_BOTTOM_RIGHT:
       x = work_area_.right() - HorizontalEdgeMargin();
-      y = work_area_.bottom() - VerticalEdgeMargin();
+      y = work_area_.bottom() - VerticalEdgeMargin() -
+          offset_to_move_above_panels_;
       break;
     default:
       NOTREACHED();
@@ -311,30 +354,21 @@ gfx::Point BalloonCollectionImpl::Layout::NextPosition(
 }
 
 gfx::Point BalloonCollectionImpl::Layout::OffScreenLocation() const {
-  int x = 0;
-  int y = 0;
+  gfx::Point location = GetLayoutOrigin();
   switch (placement_) {
     case VERTICALLY_FROM_TOP_LEFT:
-      x = work_area_.x() + HorizontalEdgeMargin();
-      y = work_area_.y() + kBalloonMaxHeight + VerticalEdgeMargin();
-      break;
-    case VERTICALLY_FROM_TOP_RIGHT:
-      x = work_area_.right() - kBalloonMaxWidth - HorizontalEdgeMargin();
-      y = work_area_.y() + kBalloonMaxHeight + VerticalEdgeMargin();
-      break;
     case VERTICALLY_FROM_BOTTOM_LEFT:
-      x = work_area_.x() + HorizontalEdgeMargin();
-      y = work_area_.bottom() + kBalloonMaxHeight + VerticalEdgeMargin();
+      location.Offset(0, kBalloonMaxHeight);
       break;
+    case VERTICALLY_FROM_TOP_RIGHT:
     case VERTICALLY_FROM_BOTTOM_RIGHT:
-      x = work_area_.right() - kBalloonMaxWidth - HorizontalEdgeMargin();
-      y = work_area_.bottom() + kBalloonMaxHeight + VerticalEdgeMargin();
+      location.Offset(-kBalloonMaxWidth, kBalloonMaxHeight);
       break;
     default:
       NOTREACHED();
       break;
   }
-  return gfx::Point(x, y);
+  return location;
 }
 
 bool BalloonCollectionImpl::Layout::RequiresOffsets() const {
@@ -363,6 +397,68 @@ gfx::Size BalloonCollectionImpl::Layout::ConstrainToSizeLimits(
                std::min(max_balloon_height(), size.height())));
 }
 
+bool BalloonCollectionImpl::Layout::ComputeOffsetToMoveAbovePanels(
+    const gfx::Rect& panel_bounds) {
+  const PanelManager::Panels& panels = PanelManager::GetInstance()->panels();
+  int offset_to_move_above_panels = 0;
+
+  // The offset is the maximum height of panels that could overlap with the
+  // balloons.
+  if (NeedToMoveAboveLeftSidePanels()) {
+    // If the affecting panel does not lie in the balloon area, no need to
+    // update the offset.
+    if (!panel_bounds.IsEmpty() &&
+        (panel_bounds.right() <= work_area_.x() ||
+         panel_bounds.x() >= work_area_.x() + max_balloon_width())) {
+      return false;
+    }
+
+    for (PanelManager::Panels::const_reverse_iterator iter = panels.rbegin();
+         iter != panels.rend(); ++iter) {
+      // No need to check panels beyond the area occupied by the balloons.
+      if ((*iter)->GetBounds().x() >= work_area_.x() + max_balloon_width())

[jennb, 2011/11/11 23:02:43]

FYI, until your overflow changes are in, this will cause balloons to be affected
by tall overflow panels appearing offscreen.

No need to fix now as you're almost done with overflow changes.

+        break;
+
+      int current_height = (*iter)->GetBounds().height();
+      if (current_height > offset_to_move_above_panels)
+        offset_to_move_above_panels = current_height;
+    }
+  } else if (NeedToMoveAboveRightSidePanels()) {
+    // If the affecting panel does not lie in the balloon area, no need to
+    // update the offset.
+    if (!panel_bounds.IsEmpty() &&
+        (panel_bounds.right() <= work_area_.right() - max_balloon_width() ||
+         panel_bounds.x() >= work_area_.right())) {
+      return false;
+    }
+
+    for (PanelManager::Panels::const_iterator iter = panels.begin();
+         iter != panels.end(); ++iter) {
+      // No need to check panels beyond the area occupied by the balloons.
+      if ((*iter)->GetBounds().right() <=
+          work_area_.right() - max_balloon_width())
+        break;
+
+      int current_height = (*iter)->GetBounds().height();
+      if (current_height > offset_to_move_above_panels)
+        offset_to_move_above_panels = current_height;
+    }
+  }
+
+  // Ensure that we have some sort of margin between the 1st balloon and the
+  // panel beneath it even the vertical edge margin is 0 as on Mac.
+  if (offset_to_move_above_panels && !VerticalEdgeMargin())
+    offset_to_move_above_panels += kVerticalSpacingBetweenBalloonAndPanel;
+
+  // If no change is detected, return false to indicate that we do not need to
+  // reposition balloons.
+  if (offset_to_move_above_panels_ == offset_to_move_above_panels)
+    return false;
+
+  offset_to_move_above_panels_ = offset_to_move_above_panels;
+  return true;
+}
+
 bool BalloonCollectionImpl::Layout::RefreshSystemMetrics() {
   bool changed = false;