[MacViews] Implement size constraints for app windows.

ui/gfx/mac/nswindow_util.mm

+// Copyright 2015 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.
+
+#import "ui/gfx/mac/nswindow_util.h"
+
+#import "base/mac/mac_util.h"
+#import "base/mac/sdk_forward_declarations.h"
+#include "ui/gfx/geometry/size.h"
+
+namespace {
+
+// The value used to represent an unbounded width or height.
+const int kUnboundedSize = 0;

[tapted, 2015/03/30 06:33:37]

since `const` has internal linkage implicitly, this can be removed from the
anonymous namespace (I'm pretty sure Nico prefers this, and he will probably be
the OWNER reviewer :). But since I suggested an anonymous namespace for the
functions below, in another comment, I'd maybe just keep it for now and see what
nico thinks

+
+}  // namespace
+
+void SetFullScreenCollectionBehavior(NSWindow* window, bool allow_fullscreen) {
+  NSWindowCollectionBehavior behavior = [window collectionBehavior];
+  if (allow_fullscreen)
+    behavior |= NSWindowCollectionBehaviorFullScreenPrimary;
+  else
+    behavior &= ~NSWindowCollectionBehaviorFullScreenPrimary;
+  [window setCollectionBehavior:behavior];
+}
+
+void SetResizableStyleMask(NSWindow* window, bool resizable) {
+  NSUInteger style_mask = [window styleMask];
+  if (resizable)
+    style_mask |= NSResizableWindowMask;
+  else
+    style_mask &= ~NSResizableWindowMask;
+  [window setStyleMask:style_mask];
+}
+
+void ApplySizeConstraints(NSWindow* window,
+                          const gfx::Size& min_size,
+                          const gfx::Size& max_size,
+                          bool can_resize,
+                          bool can_fullscreen) {
+  [window setContentMinSize:NSMakeSize(min_size.width(), min_size.height())];
+
+  CGFloat max_width =
+      max_size.width() == kUnboundedSize ? CGFLOAT_MAX : max_size.width();
+  CGFloat max_height =
+      max_size.height() == kUnboundedSize ? CGFLOAT_MAX : max_size.height();
+  [window setContentMaxSize:NSMakeSize(max_width, max_height)];
+
+  SetResizableStyleMask(window, can_resize);
+  if (base::mac::IsOSSnowLeopard())

[tapted, 2015/03/30 06:33:37]

Maybe a comment why this is snow leopard only (i.e. Apple stopped putting resize
indicators on the UI? - but is there a reason why it's not just set for all OSes
(would it break stuff?)

[jackhou1, 2015/03/31 00:50:42]

Done.

+    [window setShowsResizeIndicator:can_resize];
+
+  // Set the window to participate in Lion Fullscreen mode. Setting this flag
+  // has no effect on Snow Leopard or earlier. UI controls for fullscreen are
+  // only shown for apps that have unbounded size.
+  if (base::mac::IsOSLionOrLater())
+    SetFullScreenCollectionBehavior(window, can_fullscreen);
+
+  [[window standardWindowButton:NSWindowZoomButton] setEnabled:can_fullscreen];
+}