blob: cc920b882ae8822702cff7a03d9a2dc8598482b6 [file] [log] [blame]
// 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 <memory>
#include "base/macros.h"
#include "ui/compositor/layer_animation_observer.h"
#include "ui/compositor/layer_owner.h"
#include "ui/gfx/geometry/rect.h"
namespace gfx {
struct ShadowDetails;
} // namespace gfx
namespace ui {
class Layer;
// Simple class that draws a drop shadow around content at given bounds.
class Shadow : public ui::ImplicitAnimationObserver, public ui::LayerOwner {
~Shadow() override;
// Initialize for the the given shadow |elevation|. This is passed to
// gfx::ShadowValue::MakeMdShadowValues() and controls the y-offset and blur
// for the shadow style.
void Init(int elevation);
// Exposed to allow setting animation parameters for bounds and opacity
// animations.
ui::Layer* shadow_layer() { return shadow_layer_owner_.layer(); }
ui::Layer* fading_layer() { return fading_layer_owner_.layer(); }
const gfx::Rect& content_bounds() const { return content_bounds_; }
int desired_elevation() const { return desired_elevation_; }
// Moves and resizes the shadow layer to frame |content_bounds|.
// This should be used to adjust the shadow's size and position (rather than
// applying transformations to the `layer()` of this Shadow).
void SetContentBounds(const gfx::Rect& content_bounds);
// Sets the shadow's appearance, animating opacity as necessary.
void SetElevation(int elevation);
// Sets the radius for the rounded corners to take into account when
// adjusting the shadow layer to frame |content_bounds|. 0 or greater.
void SetRoundedCornerRadius(int rounded_corner_radius);
const gfx::ShadowDetails* details_for_testing() const { return details_; }
// ui::ImplicitAnimationObserver overrides:
void OnImplicitAnimationsCompleted() override;
// A shadow layer owner that correctly updates the nine patch layer details
// when it gets recreated.
class ShadowLayerOwner : public ui::LayerOwner {
explicit ShadowLayerOwner(Shadow* owner,
std::unique_ptr<Layer> layer = nullptr);
~ShadowLayerOwner() override;
// ui::LayerOwner:
std::unique_ptr<Layer> RecreateLayer() override;
Shadow* const owner_shadow_;
// Updates the shadow layer and its image to reflect |desired_elevation_|.
void RecreateShadowLayer();
// Updates the shadow layer bounds based on the inteior inset and the current
// |content_bounds_|.
void UpdateLayerBounds();
// The goal elevation, set when the transition animation starts. The elevation
// dictates the shadow's display characteristics and is proportional to the
// size of the blur and its offset. This may not match reality if the window
// isn't big enough to support it.
int desired_elevation_ = 0;
// Rounded corners are drawn on top of the window's content layer,
// we need to exclude them from the occlusion area.
int rounded_corner_radius_ = 2;
// The details of the shadow image that's currently set on |shadow_layer()|.
// This will be null until a positive elevation has been set. Once set, it
// will always point to a global ShadowDetails instance that is guaranteed
// to outlive the Shadow instance. See ui/gfx/shadow_util.h for how these
// ShadowDetails instances are created.
const gfx::ShadowDetails* details_ = nullptr;
// The owner of the actual shadow layer corresponding to a cc::NinePatchLayer.
ShadowLayerOwner shadow_layer_owner_;
// When the elevation changes, the old shadow cross-fades with the new one.
// When non-null, this owns an old |shadow_layer()| that's being animated out.
ui::LayerOwner fading_layer_owner_;
// Bounds of the content that the shadow encloses.
gfx::Rect content_bounds_;
} // namespace ui