chromium/third_party/blink/renderer/core/frame/visual_viewport.h

/*
 * copyright (c) 2013 google inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_FRAME_VISUAL_VIEWPORT_H_
#define THIRD_PARTY_BLINK_RENDERER_CORE_FRAME_VISUAL_VIEWPORT_H_

#include <memory>

#include "base/notreached.h"
#include "base/task/single_thread_task_runner.h"
#include "third_party/blink/public/mojom/scroll/scroll_into_view_params.mojom-blink-forward.h"
#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/dom/document.h"
#include "third_party/blink/renderer/core/dom/events/event.h"
#include "third_party/blink/renderer/core/scroll/scroll_types.h"
#include "third_party/blink/renderer/core/scroll/scrollable_area.h"
#include "third_party/blink/renderer/platform/graphics/compositor_element_id.h"
#include "third_party/blink/renderer/platform/graphics/paint/property_tree_state.h"
#include "ui/gfx/geometry/rect_f.h"
#include "ui/gfx/geometry/size.h"
#include "ui/gfx/geometry/size_f.h"
#include "ui/gfx/geometry/vector2d_conversions.h"

namespace cc {
class AnimationHost;
class AnimationTimeline;
class SolidColorScrollbarLayer;
}

namespace blink {

enum class PaintPropertyChangeType : unsigned char;
class EffectPaintPropertyNode;
class GraphicsContext;
class LocalFrame;
class Page;
class PaintArtifactCompositor;
class RootFrameViewport;
class ScrollPaintPropertyNode;
class TracedValue;
class TransformPaintPropertyNode;
struct PaintPropertyTreeBuilderFragmentContext;

enum class OverscrollType { … };

// Represents the visual viewport the user is currently seeing the page through.
// This class corresponds to the InnerViewport on the compositor. It is a
// ScrollableArea; it's offset is set through the GraphicsLayer <-> CC sync
// mechanisms. Its contents is the page's main LocalFrameView, which corresponds
// to the outer viewport. The inner viewport is always contained in the outer
// viewport and can pan within it.
//
// When attached, we will create the following layers:
// - scroll_layer_ (transform: scroll_translation_node_)
// - scrollbar_layer_horizontal_ (optional, transform: DET_or_parent)
// - scrollbar_layer_vertical_ (optional, transform: DET_or_parent)
// (DET_or_parent: device_emulation_transform_node_ if exists,
//  or the parent transform state)
//
// After PrePaint, the property trees will look like this:
//
// Transform tree:
//  parent transform state
//  +- device_emulation_transform_node_ (optional)
//     +- overscroll_elasticity_transform_node_
//        +- page_scale_node__
//           +- scroll_translation_node_ (scroll: scroll_node_)
// Effect tree:
//  parent effect state
//  +- horizontal_scrollbar_effect_node_
//  +- vertical_scrollbar_effect_node_
//
// A VisualViewport is created for each blink::Page which means we'll have a
// VisualViewport for each renderer in a page. However, only the VisualViewport
// in the renderer containing the outermost main frame is considered active.
// VisualViewports that are remote to the outermost main frame are considered
// inert; their scale and location values cannot be changed. See the
// IsActiveViewport() method. Many methods in VisualViewport either return
// defaults or expect to never be called from an inert instance.
class CORE_EXPORT VisualViewport : public GarbageCollected<VisualViewport>,
                                   public ScrollableArea { … };

}  // namespace blink

#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_FRAME_VISUAL_VIEWPORT_H_