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// Copyright 2013 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 "cc/input/top_controls_manager.h"
#include <algorithm>
#include "base/logging.h"
#include "cc/animation/keyframed_animation_curve.h"
#include "cc/animation/timing_function.h"
#include "cc/input/top_controls_manager_client.h"
#include "cc/output/begin_frame_args.h"
#include "cc/trees/layer_tree_impl.h"
#include "ui/gfx/geometry/vector2d_f.h"
#include "ui/gfx/transform.h"
namespace cc {
namespace {
// These constants were chosen empirically for their visually pleasant behavior.
// Contact tedchoc@chromium.org for questions about changing these values.
const int64 kShowHideMaxDurationMs = 200;
}
// static
scoped_ptr<TopControlsManager> TopControlsManager::Create(
TopControlsManagerClient* client,
float top_controls_show_threshold,
float top_controls_hide_threshold) {
return make_scoped_ptr(new TopControlsManager(client,
top_controls_show_threshold,
top_controls_hide_threshold));
}
TopControlsManager::TopControlsManager(TopControlsManagerClient* client,
float top_controls_show_threshold,
float top_controls_hide_threshold)
: client_(client),
animation_direction_(NO_ANIMATION),
permitted_state_(BOTH),
accumulated_scroll_delta_(0.f),
baseline_content_offset_(0.f),
top_controls_show_threshold_(top_controls_hide_threshold),
top_controls_hide_threshold_(top_controls_show_threshold),
pinch_gesture_active_(false) {
CHECK(client_);
}
TopControlsManager::~TopControlsManager() {
}
float TopControlsManager::ControlsTopOffset() const {
return ContentTopOffset() - TopControlsHeight();
}
float TopControlsManager::ContentTopOffset() const {
return TopControlsShownRatio() * TopControlsHeight();
}
float TopControlsManager::TopControlsShownRatio() const {
return client_->CurrentTopControlsShownRatio();
}
float TopControlsManager::TopControlsHeight() const {
return client_->TopControlsHeight();
}
void TopControlsManager::UpdateTopControlsState(TopControlsState constraints,
TopControlsState current,
bool animate) {
DCHECK(!(constraints == SHOWN && current == HIDDEN));
DCHECK(!(constraints == HIDDEN && current == SHOWN));
permitted_state_ = constraints;
// Don't do anything if it doesn't matter which state the controls are in.
if (constraints == BOTH && current == BOTH)
return;
// Don't do anything if there is no change in offset.
float final_shown_ratio = 1.f;
if (constraints == HIDDEN || current == HIDDEN)
final_shown_ratio = 0.f;
if (final_shown_ratio == TopControlsShownRatio())
return;
if (animate) {
SetupAnimation(final_shown_ratio ? SHOWING_CONTROLS : HIDING_CONTROLS);
} else {
ResetAnimations();
client_->SetCurrentTopControlsShownRatio(final_shown_ratio);
}
}
void TopControlsManager::ScrollBegin() {
DCHECK(!pinch_gesture_active_);
ResetAnimations();
ResetBaseline();
}
gfx::Vector2dF TopControlsManager::ScrollBy(
const gfx::Vector2dF& pending_delta) {
if (!TopControlsHeight())
return pending_delta;
if (pinch_gesture_active_)
return pending_delta;
if (permitted_state_ == SHOWN && pending_delta.y() > 0)
return pending_delta;
else if (permitted_state_ == HIDDEN && pending_delta.y() < 0)
return pending_delta;
accumulated_scroll_delta_ += pending_delta.y();
float old_offset = ContentTopOffset();
client_->SetCurrentTopControlsShownRatio(
(baseline_content_offset_ - accumulated_scroll_delta_) /
TopControlsHeight());
// If the controls are fully visible, treat the current position as the
// new baseline even if the gesture didn't end.
if (TopControlsShownRatio() == 1.f)
ResetBaseline();
ResetAnimations();
gfx::Vector2dF applied_delta(0.f, old_offset - ContentTopOffset());
return pending_delta - applied_delta;
}
void TopControlsManager::ScrollEnd() {
DCHECK(!pinch_gesture_active_);
StartAnimationIfNecessary();
}
void TopControlsManager::PinchBegin() {
DCHECK(!pinch_gesture_active_);
pinch_gesture_active_ = true;
StartAnimationIfNecessary();
}
void TopControlsManager::PinchEnd() {
DCHECK(pinch_gesture_active_);
// Pinch{Begin,End} will always occur within the scope of Scroll{Begin,End},
// so return to a state expected by the remaining scroll sequence.
pinch_gesture_active_ = false;
ScrollBegin();
}
void TopControlsManager::MainThreadHasStoppedFlinging() {
StartAnimationIfNecessary();
}
gfx::Vector2dF TopControlsManager::Animate(base::TimeTicks monotonic_time) {
if (!top_controls_animation_ || !client_->HaveRootScrollLayer())
return gfx::Vector2dF();
base::TimeDelta time = monotonic_time - base::TimeTicks();
float old_offset = ContentTopOffset();
client_->SetCurrentTopControlsShownRatio(
top_controls_animation_->GetValue(time));
if (IsAnimationCompleteAtTime(monotonic_time))
ResetAnimations();
gfx::Vector2dF scroll_delta(0.f, ContentTopOffset() - old_offset);
return scroll_delta;
}
void TopControlsManager::ResetAnimations() {
top_controls_animation_ = nullptr;
animation_direction_ = NO_ANIMATION;
}
void TopControlsManager::SetupAnimation(AnimationDirection direction) {
DCHECK_NE(NO_ANIMATION, direction);
DCHECK(direction != HIDING_CONTROLS || TopControlsShownRatio() > 0.f);
DCHECK(direction != SHOWING_CONTROLS || TopControlsShownRatio() < 1.f);
if (top_controls_animation_ && animation_direction_ == direction)
return;
if (!TopControlsHeight()) {
client_->SetCurrentTopControlsShownRatio(
direction == HIDING_CONTROLS ? 0.f : 1.f);
return;
}
top_controls_animation_ = KeyframedFloatAnimationCurve::Create();
base::TimeDelta start_time = base::TimeTicks::Now() - base::TimeTicks();
top_controls_animation_->AddKeyframe(
FloatKeyframe::Create(start_time, TopControlsShownRatio(), nullptr));
float max_ending_ratio = (direction == SHOWING_CONTROLS ? 1 : -1);
top_controls_animation_->AddKeyframe(FloatKeyframe::Create(
start_time + base::TimeDelta::FromMilliseconds(kShowHideMaxDurationMs),
TopControlsShownRatio() + max_ending_ratio,
EaseTimingFunction::Create()));
animation_direction_ = direction;
client_->DidChangeTopControlsPosition();
}
void TopControlsManager::StartAnimationIfNecessary() {
if (TopControlsShownRatio() == 0.f || TopControlsShownRatio() == 1.f)
return;
if (TopControlsShownRatio() >= 1.f - top_controls_hide_threshold_) {
// If we're showing so much that the hide threshold won't trigger, show.
SetupAnimation(SHOWING_CONTROLS);
} else if (TopControlsShownRatio() <= top_controls_show_threshold_) {
// If we're showing so little that the show threshold won't trigger, hide.
SetupAnimation(HIDING_CONTROLS);
} else {
// If we could be either showing or hiding, we determine which one to
// do based on whether or not the total scroll delta was moving up or
// down.
SetupAnimation(accumulated_scroll_delta_ <= 0.f ? SHOWING_CONTROLS
: HIDING_CONTROLS);
}
}
bool TopControlsManager::IsAnimationCompleteAtTime(base::TimeTicks time) {
if (!top_controls_animation_)
return true;
base::TimeDelta animation_time = time - base::TimeTicks();
float new_ratio = top_controls_animation_->GetValue(animation_time);
if ((animation_direction_ == SHOWING_CONTROLS && new_ratio >= 1.f) ||
(animation_direction_ == HIDING_CONTROLS && new_ratio <= 0.f)) {
return true;
}
return false;
}
void TopControlsManager::ResetBaseline() {
accumulated_scroll_delta_ = 0.f;
baseline_content_offset_ = ContentTopOffset();
}
} // namespace cc
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