chromium/ui/views/controls/scroll_view.h

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_VIEWS_CONTROLS_SCROLL_VIEW_H_
#define UI_VIEWS_CONTROLS_SCROLL_VIEW_H_

#include <memory>
#include <optional>
#include <utility>

#include "base/callback_list.h"
#include "base/gtest_prod_util.h"
#include "base/memory/raw_ptr.h"
#include "ui/color/color_id.h"
#include "ui/compositor/layer_type.h"
#include "ui/views/controls/focus_ring.h"
#include "ui/views/controls/scrollbar/scroll_bar.h"
#include "ui/views/controls/separator.h"

namespace cc {
struct ElementId;
}

namespace gfx {
class PointF;
class RoundedCornersF;
}

namespace views {
namespace test {
class ScrollViewTestApi;
}

enum class OverflowIndicatorAlignment { … };

/////////////////////////////////////////////////////////////////////////////
//
// ScrollView class
//
// A ScrollView is used to make any View scrollable. The view is added to
// a viewport which takes care of clipping.
//
// In this current implementation both horizontal and vertical scrollbars are
// added as needed.
//
// The scrollview supports keyboard UI and mousewheel.
//
/////////////////////////////////////////////////////////////////////////////

class VIEWS_EXPORT ScrollView : public View, public ScrollBarController { … };

// When building with GCC this ensures that an instantiation of the
// ScrollView::SetContents<View> template is available with which to link.
template View* ScrollView::SetContents<View>(std::unique_ptr<View> a_view);

BEGIN_VIEW_BUILDER(VIEWS_EXPORT, ScrollView, View)
VIEW_BUILDER_VIEW_TYPE_PROPERTY(View, Contents)
VIEW_BUILDER_PROPERTY(ui::LayerType, ContentsLayerType)
VIEW_BUILDER_VIEW_TYPE_PROPERTY(View, Header)
VIEW_BUILDER_PROPERTY(bool, AllowKeyboardScrolling)
VIEW_BUILDER_PROPERTY(std::optional<ui::ColorId>, BackgroundThemeColorId)
VIEW_BUILDER_METHOD(ClipHeightTo, int, int)
VIEW_BUILDER_PROPERTY(ScrollView::ScrollBarMode, HorizontalScrollBarMode)
VIEW_BUILDER_PROPERTY(ScrollView::ScrollBarMode, VerticalScrollBarMode)
VIEW_BUILDER_PROPERTY(bool, TreatAllScrollEventsAsHorizontal)
VIEW_BUILDER_PROPERTY(bool, DrawOverflowIndicator)
VIEW_BUILDER_PROPERTY(std::optional<SkColor>, BackgroundColor)
VIEW_BUILDER_VIEW_PROPERTY(ScrollBar, HorizontalScrollBar)
VIEW_BUILDER_VIEW_PROPERTY(ScrollBar, VerticalScrollBar)
VIEW_BUILDER_PROPERTY(bool, HasFocusIndicator)
END_VIEW_BUILDER

// VariableRowHeightScrollHelper is intended for views that contain rows of
// varying height. To use a VariableRowHeightScrollHelper create one supplying
// a Controller and delegate GetPageScrollIncrement and GetLineScrollIncrement
// to the helper. VariableRowHeightScrollHelper calls back to the
// Controller to determine row boundaries.
class VariableRowHeightScrollHelper { … };

// FixedRowHeightScrollHelper is intended for views that contain fixed height
// height rows. To use a FixedRowHeightScrollHelper delegate
// GetPageScrollIncrement and GetLineScrollIncrement to it.
class FixedRowHeightScrollHelper : public VariableRowHeightScrollHelper { … };

}  // namespace views

DEFINE_VIEW_BUILDER(…)

#endif  // UI_VIEWS_CONTROLS_SCROLL_VIEW_H_