Bug Fix: Scroll View Shows Unnecessary Scrollbar

ui/views/controls/scroll_view.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/controls/scroll_view.h"
 
 #include "base/feature_list.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "ui/events/event.h"
@@ skipping 276 matching lines @@
   if (!is_bounded())
     return View::GetHeightForWidth(width);
 
   gfx::Insets insets = GetInsets();
   width = std::max(0, width - insets.width());
   int height = contents()->GetHeightForWidth(width) + insets.height();
   return std::min(std::max(height, min_height_), max_height_);
 }
 
 void ScrollView::Layout() {
+  gfx::Rect available_rect = GetContentsBounds();
   if (is_bounded()) {
-    int content_width = width();
+    int content_width = available_rect.width();
     int content_height = contents()->GetHeightForWidth(content_width);
     if (content_height > height()) {
       content_width = std::max(content_width - GetScrollBarWidth(), 0);
       content_height = contents()->GetHeightForWidth(content_width);
     }
     if (contents()->bounds().size() != gfx::Size(content_width, content_height))
       contents()->SetBounds(0, 0, content_width, content_height);
   }
 
   // Most views will want to auto-fit the available space. Most of them want to
   // use all available width (without overflowing) and only overflow in
   // height. Examples are HistoryView, MostVisitedView, DownloadTabView, etc.
   // Other views want to fit in both ways. An example is PrintView. To make both
   // happy, assume a vertical scrollbar but no horizontal scrollbar. To override
   // this default behavior, the inner view has to calculate the available space,
   // used ComputeScrollBarsVisibility() to use the same calculation that is done
   // here and sets its bound to fit within.
-  gfx::Rect viewport_bounds = GetContentsBounds();
+  gfx::Rect viewport_bounds = available_rect;
   const int contents_x = viewport_bounds.x();
   const int contents_y = viewport_bounds.y();
   if (viewport_bounds.IsEmpty()) {
     // There's nothing to layout.
     return;
   }
 
   const int header_height =
       std::min(viewport_bounds.height(),
                header_ ? header_->GetPreferredSize().height() : 0);
@@ skipping 257 matching lines @@
                                         contents_viewport_->height());
 
   ScrollToOffset(gfx::ScrollOffset(new_x, new_y));
   UpdateScrollBarPositions();
 }
 
 void ScrollView::ComputeScrollBarsVisibility(const gfx::Size& vp_size,
                                              const gfx::Size& content_size,
                                              bool* horiz_is_shown,
                                              bool* vert_is_shown) const {
+  if (hide_horizontal_scrollbar_) {
+    *horiz_is_shown = false;
+    *vert_is_shown = content_size.height() > vp_size.height();
+    return;
+  }
+
   // Try to fit both ways first, then try vertical bar only, then horizontal
   // bar only, then defaults to both shown.
   if (content_size.width() <= vp_size.width() &&
       content_size.height() <= vp_size.height()) {
     *horiz_is_shown = false;
     *vert_is_shown = false;
   } else if (content_size.width() <= vp_size.width() - GetScrollBarWidth()) {
     *horiz_is_shown = false;
     *vert_is_shown = true;
   } else if (content_size.height() <= vp_size.height() - GetScrollBarHeight()) {
     *horiz_is_shown = true;
     *vert_is_shown = false;
   } else {
     *horiz_is_shown = true;
     *vert_is_shown = true;
   }
-
-  if (hide_horizontal_scrollbar_)
-    *horiz_is_shown = false;
 }
 
 // Make sure that a single scrollbar is created and visible as needed
 void ScrollView::SetControlVisibility(View* control, bool should_show) {
   if (!control)
     return;
   if (should_show) {
     if (!control->visible()) {
       AddChildView(control);
       control->SetVisible(true);
@@ skipping 131 matching lines @@
 
 VariableRowHeightScrollHelper::RowInfo
     FixedRowHeightScrollHelper::GetRowInfo(int y) {
   if (y < top_margin_)
     return RowInfo(0, top_margin_);
   return RowInfo((y - top_margin_) / row_height_ * row_height_ + top_margin_,
                  row_height_);
 }
 
 }  // namespace views