make BoxLayout use and respect GetHeightForWidth().

ui/views/layout/box_layout.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/layout/box_layout.h"
 
 #include "ui/gfx/insets.h"
 #include "ui/gfx/rect.h"
 #include "ui/views/view.h"
 
@@ skipping 22 matching lines @@
   int y = child_area.y();
 
   int padding = 0;
   if (spread_blank_space_) {
     int total = 0;
     int visible = 0;
     for (int i = 0; i < host->child_count(); ++i) {
       View* child = host->child_at(i);
       if (!child->visible())
         continue;
-      if (orientation_ == kHorizontal)
+      if (orientation_ == kHorizontal) {
         total += child->GetPreferredSize().width() + between_child_spacing_;
-      else
-        total += child->GetPreferredSize().height() + between_child_spacing_;
+      } else {
+        total += child->GetHeightForWidth(child_area.width()) +
+            between_child_spacing_;
+      }
       ++visible;
     }
 
     if (visible) {
       total -= between_child_spacing_;
       if (orientation_ == kHorizontal)
         padding = (child_area.width() - total) / visible;
       else
         padding = (child_area.height() - total) / visible;
 
       if (padding < 0)
         padding = 0;
     }
   }
 
   for (int i = 0; i < host->child_count(); ++i) {
     View* child = host->child_at(i);
     if (child->visible()) {
       gfx::Rect bounds(x, y, child_area.width(), child_area.height());
-      gfx::Size size(child->GetPreferredSize());
       if (orientation_ == kHorizontal) {
-        bounds.set_width(size.width() + padding);
-        x += size.width() + between_child_spacing_ + padding;
+        bounds.set_width(child->GetPreferredSize().width() + padding);
+        x += bounds.width() + between_child_spacing_;
       } else {
-        bounds.set_height(size.height() + padding);
-        y += size.height() + between_child_spacing_ + padding;
+        bounds.set_height(child->GetHeightForWidth(bounds.width()) + padding);
+        y += bounds.height() + between_child_spacing_;
       }
       // Clamp child view bounds to |child_area|.
       bounds.Intersect(child_area);
       child->SetBoundsRect(bounds);
     }
   }
 }
 
 gfx::Size BoxLayout::GetPreferredSize(View* host) {

[sky, 2013/03/13 14:03:03]

You should also override GetPreferredSizeForWidth now.

[Evan Stade, 2013/03/13 23:49:56]

done, although I didn't add an implementation for horizontal layouts, which
would require re-using the code in Layout(). IMO we can cross that bridge when
we come to it.

   gfx::Rect bounds;
-  int position = 0;
-  for (int i = 0; i < host->child_count(); ++i) {
-    View* child = host->child_at(i);
-    if (child->visible()) {
+
+  if (orientation_ == kHorizontal) {
+    int position = 0;
+    for (int i = 0; i < host->child_count(); ++i) {
+      View* child = host->child_at(i);
+      if (!child->visible())
+        continue;
+
       gfx::Size size(child->GetPreferredSize());
-      if (orientation_ == kHorizontal) {
-        gfx::Rect child_bounds(position, 0, size.width(), size.height());
-        bounds.Union(child_bounds);
-        position += size.width();
-      } else {
-        gfx::Rect child_bounds(0, position, size.width(), size.height());
-        bounds.Union(child_bounds);
-        position += size.height();
-      }
-      position += between_child_spacing_;
+      gfx::Rect child_bounds(position, 0, size.width(), size.height());
+      bounds.Union(child_bounds);
+      position += size.width() + between_child_spacing_;
     }
+  } else {
+    int width = 0;
+    for (int i = 0; i < host->child_count(); ++i) {
+      View* child = host->child_at(i);
+      if (!child->visible())
+        continue;
+
+      width = std::max(width, child->GetPreferredSize().width());
+    }
+
+    int height = 0;
+    for (int i = 0; i < host->child_count(); ++i) {
+      View* child = host->child_at(i);
+      if (!child->visible())
+        continue;
+
+      height += child->GetHeightForWidth(width);
+      if (i != 0)
+        height += between_child_spacing_;
+    }
+
+    bounds.set_width(width);
+    bounds.set_height(height);
   }
   gfx::Insets insets(host->GetInsets());
   return gfx::Size(
       bounds.width() + insets.width() + 2 * inside_border_horizontal_spacing_,
       bounds.height() + insets.height() + 2 * inside_border_vertical_spacing_);
 }
 
 } // namespace views