Add ability to set a flag in the Label view class that tells it to

return a preferred size of 0, 0 when the label is not visible.

Review URL: http://codereview.chromium.org/21313

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@9725 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 22 insertions, 0 deletions

diff --git a/chrome/views/label.cc b/chrome/views/label.cc
index bd9ddf61..f0c38d8 100644
--- a/chrome/views/label.cc
+++ b/chrome/views/label.cc
@@ -44,6 +44,7 @@ void Label::Init(const std::wstring& text, const ChromeFont& font) {
   color_ = kEnabledColor;
   horiz_alignment_ = ALIGN_CENTER;
   is_multi_line_ = false;
+  collapse_when_hidden_ = false;
 }
 
 Label::~Label() {
@@ -51,6 +52,15 @@ Label::~Label() {
 
 gfx::Size Label::GetPreferredSize() {
   gfx::Size prefsize;
+
+  // Return a size of (0, 0) if the label is not visible and if the
+  // collapse_when_hidden_ flag is set.
+  // TODO(munjal): This logic probably belongs to the View class. But for now,
+  // put it here since putting it in View class means all inheriting classes
+  // need ot respect the collapse_when_hidden_ flag.
+  if (!IsVisible() && collapse_when_hidden_)
+    return prefsize;
+
   if (is_multi_line_) {
     int w = width(), h = 0;
     ChromeCanvas::SizeStringInt(text_, font_, &w, &h, ComputeMultiLineFlags());
diff --git a/chrome/views/label.h b/chrome/views/label.h
index 385518d..84e685c 100644
--- a/chrome/views/label.h
+++ b/chrome/views/label.h
@@ -143,6 +143,12 @@ class Label : public View {
   virtual bool GetAccessibleState(VARIANT* state);
 #endif  // defined(OS_WIN)
 
+  // Gets/sets the flag to determine whether the label should be collapsed when
+  // it's hidden (not visible). If this flag is true, the label will return a
+  // preferred size of (0, 0) when it's not visible.
+  void set_collapse_when_hidden(bool value) { collapse_when_hidden_ = value; }
+  bool collapse_when_hidden() const { return collapse_when_hidden_; }
+
  private:
   // These tests call CalculateDrawStringParams in order to verify the
   // calculations done for drawing text.
@@ -184,6 +190,10 @@ class Label : public View {
   // Whether the mouse is over this label.
   bool contains_mouse_;
   scoped_ptr<Background> mouse_over_background_;
+  // Whether to collapse the label when it's not visible.
+  bool collapse_when_hidden_;
+
+  DISALLOW_COPY_AND_ASSIGN(Label);
 };
 
 }  // namespace views
diff --git a/chrome/views/link.h b/chrome/views/link.h
index e80b1795..87d7d85 100644
--- a/chrome/views/link.h
+++ b/chrome/views/link.h
@@ -85,6 +85,8 @@ class Link : public Label {
 
   // The color when the link is neither highlighted nor disabled.
   SkColor normal_color_;
+
+  DISALLOW_COPY_AND_ASSIGN(Link);
 };
 
 }  // namespace views