blob: e24cfa52ca0421db94382351e5264b8b6a9426ff [file] [log] [blame]
// Copyright 2017 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.
#import "ios/chrome/browser/ui/fullscreen/fullscreen_model.h"
#include <algorithm>
#include "base/check_op.h"
#import "ios/chrome/browser/ui/fullscreen/fullscreen_model_observer.h"
#include "ios/chrome/browser/ui/util/ui_util.h"
#if !defined(__has_feature) || !__has_feature(objc_arc)
#error "This file requires ARC support."
#endif
namespace {
// Object that increments |counter| by 1 for its lifetime.
class ScopedIncrementer {
public:
explicit ScopedIncrementer(size_t* counter) : counter_(counter) {
++(*counter_);
}
~ScopedIncrementer() { --(*counter_); }
private:
size_t* counter_;
};
}
FullscreenModel::FullscreenModel() = default;
FullscreenModel::~FullscreenModel() = default;
void FullscreenModel::IncrementDisabledCounter() {
if (++disabled_counter_ == 1U) {
ScopedIncrementer disabled_incrementer(&observer_callback_count_);
for (auto& observer : observers_) {
observer.FullscreenModelEnabledStateChanged(this);
}
// Fullscreen observers are expected to show the toolbar when fullscreen is
// disabled. Update the internal state to match this.
SetProgress(1.0);
UpdateBaseOffset();
}
}
void FullscreenModel::DecrementDisabledCounter() {
DCHECK_GT(disabled_counter_, 0U);
if (!--disabled_counter_) {
ScopedIncrementer enabled_incrementer(&observer_callback_count_);
for (auto& observer : observers_) {
observer.FullscreenModelEnabledStateChanged(this);
}
}
}
void FullscreenModel::ResetForNavigation() {
progress_ = 1.0;
scrolling_ = false;
base_offset_ = NAN;
ScopedIncrementer reset_incrementer(&observer_callback_count_);
for (auto& observer : observers_) {
observer.FullscreenModelWasReset(this);
}
}
void FullscreenModel::IgnoreRemainderOfCurrentScroll() {
if (!scrolling_)
return;
ignoring_current_scroll_ = true;
}
void FullscreenModel::AnimationEndedWithProgress(CGFloat progress) {
DCHECK_GE(progress, 0.0);
DCHECK_LE(progress, 1.0);
// Since this is being set by the animator instead of by scroll events, do not
// broadcast the new progress value.
progress_ = progress;
}
void FullscreenModel::SetCollapsedToolbarHeight(CGFloat height) {
if (AreCGFloatsEqual(collapsed_toolbar_height_, height))
return;
DCHECK_GE(height, 0.0);
collapsed_toolbar_height_ = height;
base_offset_ = NAN;
ScopedIncrementer toolbar_height_incrementer(&observer_callback_count_);
for (auto& observer : observers_) {
observer.FullscreenModelToolbarHeightsUpdated(this);
}
}
CGFloat FullscreenModel::GetCollapsedToolbarHeight() const {
return collapsed_toolbar_height_;
}
void FullscreenModel::SetExpandedToolbarHeight(CGFloat height) {
if (AreCGFloatsEqual(expanded_toolbar_height_, height))
return;
DCHECK_GE(height, 0.0);
expanded_toolbar_height_ = height;
base_offset_ = NAN;
ScopedIncrementer toolbar_height_incrementer(&observer_callback_count_);
for (auto& observer : observers_) {
observer.FullscreenModelToolbarHeightsUpdated(this);
}
}
CGFloat FullscreenModel::GetExpandedToolbarHeight() const {
return expanded_toolbar_height_;
}
void FullscreenModel::SetBottomToolbarHeight(CGFloat height) {
if (AreCGFloatsEqual(bottom_toolbar_height_, height))
return;
DCHECK_GE(height, 0.0);
bottom_toolbar_height_ = height;
base_offset_ = NAN;
ScopedIncrementer toolbar_height_incrementer(&observer_callback_count_);
for (auto& observer : observers_) {
observer.FullscreenModelToolbarHeightsUpdated(this);
}
}
CGFloat FullscreenModel::GetBottomToolbarHeight() const {
return bottom_toolbar_height_;
}
void FullscreenModel::SetScrollViewHeight(CGFloat scroll_view_height) {
scroll_view_height_ = scroll_view_height;
UpdateDisabledCounterForContentHeight();
}
CGFloat FullscreenModel::GetScrollViewHeight() const {
return scroll_view_height_;
}
void FullscreenModel::SetContentHeight(CGFloat content_height) {
content_height_ = content_height;
UpdateDisabledCounterForContentHeight();
}
CGFloat FullscreenModel::GetContentHeight() const {
return content_height_;
}
void FullscreenModel::SetTopContentInset(CGFloat top_inset) {
top_inset_ = top_inset;
}
CGFloat FullscreenModel::GetTopContentInset() const {
return top_inset_;
}
void FullscreenModel::SetYContentOffset(CGFloat y_content_offset) {
CGFloat from_offset = y_content_offset_;
y_content_offset_ = y_content_offset;
switch (ActionForScrollFromOffset(from_offset)) {
case ScrollAction::kUpdateBaseOffset:
UpdateBaseOffset();
break;
case ScrollAction::kUpdateProgress:
UpdateProgress();
break;
case ScrollAction::kUpdateBaseOffsetAndProgress:
UpdateBaseOffset();
UpdateProgress();
break;
case ScrollAction::kIgnore:
// no op.
break;
}
}
CGFloat FullscreenModel::GetYContentOffset() const {
return y_content_offset_;
}
void FullscreenModel::SetScrollViewIsScrolling(bool scrolling) {
if (scrolling_ == scrolling)
return;
scrolling_ = scrolling;
if (scrolling_) {
// Notify observers that the scroll event has begun.
ScopedIncrementer scroll_started_incrementer(&observer_callback_count_);
for (auto& observer : observers_) {
observer.FullscreenModelScrollEventStarted(this);
}
} else {
// Stop ignoring the current scroll.
ignoring_current_scroll_ = false;
// Notify observers that the scroll event has ended.
ScopedIncrementer scroll_ended_incrementer(&observer_callback_count_);
for (auto& observer : observers_) {
observer.FullscreenModelScrollEventEnded(this);
}
}
}
bool FullscreenModel::IsScrollViewScrolling() const {
return scrolling_;
}
void FullscreenModel::SetScrollViewIsZooming(bool zooming) {
zooming_ = zooming;
}
bool FullscreenModel::IsScrollViewZooming() const {
return zooming_;
}
void FullscreenModel::SetScrollViewIsDragging(bool dragging) {
if (dragging_ == dragging)
return;
dragging_ = dragging;
if (dragging_) {
// Update the base offset for each new scroll event.
UpdateBaseOffset();
// Re-rendering events are ignored during scrolls since disabling the model
// mid-scroll leads to choppy animations. If the content was re-rendered
// to be too short to collapse the toolbars, the model should be disabled
// to prevent the subsequent scroll.
UpdateDisabledCounterForContentHeight();
}
}
bool FullscreenModel::IsScrollViewDragging() const {
return dragging_;
}
void FullscreenModel::SetResizesScrollView(bool resizes_scroll_view) {
resizes_scroll_view_ = resizes_scroll_view;
}
bool FullscreenModel::ResizesScrollView() const {
return resizes_scroll_view_;
}
void FullscreenModel::SetWebViewSafeAreaInsets(UIEdgeInsets safe_area_insets) {
if (UIEdgeInsetsEqualToEdgeInsets(safe_area_insets_, safe_area_insets))
return;
safe_area_insets_ = safe_area_insets;
UpdateDisabledCounterForContentHeight();
}
UIEdgeInsets FullscreenModel::GetWebViewSafeAreaInsets() const {
return safe_area_insets_;
}
FullscreenModel::ScrollAction FullscreenModel::ActionForScrollFromOffset(
CGFloat from_offset) const {
// Update the base offset but don't recalculate progress if:
// - the model is disabled,
// - the scroll is not triggered by a user action,
// - the sroll view is zooming,
// - the scroll is triggered from a FullscreenModelObserver callback,
// - there is no toolbar,
// - the scroll offset doesn't change.
if (!enabled() || !scrolling_ || zooming_ || observer_callback_count_ ||
AreCGFloatsEqual(toolbar_height_delta(), 0.0) ||
AreCGFloatsEqual(y_content_offset_, from_offset)) {
return ScrollAction::kUpdateBaseOffset;
}
// Ignore if:
// - explicitly requested via IgnoreRemainderOfCurrentScroll(),
// - the scroll is a bounce-up animation at the top,
// - the scroll is attempting to scroll content up when it already fits,
// - the scroll is attempting to scroll past the bottom of the content when
// the scroll view is being resized (the rebound scroll animation
// interferes with the frame resizing).
bool scrolling_content_down = y_content_offset_ - from_offset < 0.0;
bool scrolling_past_top = y_content_offset_ <= -top_inset_;
bool content_fits = content_height_ <= scroll_view_height_ - top_inset_;
bool scrolling_past_bottom =
y_content_offset_ + scroll_view_height_ + top_inset_ >= content_height_;
if (ignoring_current_scroll_ ||
(scrolling_past_top && !scrolling_content_down) ||
(content_fits && !scrolling_content_down) ||
(resizes_scroll_view_ && scrolling_past_bottom)) {
return ScrollAction::kIgnore;
}
// All other scrolls should result in an updated progress value. If the model
// doesn't have a base offset, it should also be updated.
return has_base_offset() ? ScrollAction::kUpdateProgress
: ScrollAction::kUpdateBaseOffsetAndProgress;
}
void FullscreenModel::UpdateBaseOffset() {
base_offset_ = y_content_offset_ - (1.0 - progress_) * toolbar_height_delta();
}
void FullscreenModel::UpdateProgress() {
CGFloat delta = base_offset_ - y_content_offset_;
SetProgress(1.0 + delta / toolbar_height_delta());
}
void FullscreenModel::UpdateDisabledCounterForContentHeight() {
// Sometimes the content size and scroll view sizes are updated mid-scroll
// such that the scroll view height is updated before the content is re-
// rendered, causing the model to be disabled. These changes should be
// ignored while the content is scrolling.
if (scrolling_)
return;
// The model should be disabled when the content fits.
CGFloat disabling_threshold = scroll_view_height_;
if (resizes_scroll_view_) {
// When Smooth Scrolling is disabled, the scroll view can sometimes be
// resized to account for the viewport insets after the page has been
// rendered, so account for the maximum toolbar insets in the threshold.
disabling_threshold += expanded_toolbar_height_ + bottom_toolbar_height_;
} else {
// After reloads, pages whose viewports fit the screen are sometimes resized
// to account for the safe area insets. Adding these to the threshold helps
// prevent fullscreen from beeing re-enabled in this case.
// TODO(crbug.com/924807): This logic can potentially disable fullscreen for
// short pages in which this bug does not occur. It should be removed once
// the page can be reloaded without resizing.
disabling_threshold += safe_area_insets_.top + safe_area_insets_.bottom;
}
// Don't disable fullscreen if both heights have not been received.
bool areBothHeightsSet = !AreCGFloatsEqual(content_height_, 0.0) &&
!AreCGFloatsEqual(scroll_view_height_, 0.0);
bool disable = areBothHeightsSet && content_height_ <= disabling_threshold;
if (disabled_for_short_content_ == disable)
return;
disabled_for_short_content_ = disable;
if (disable)
IncrementDisabledCounter();
else
DecrementDisabledCounter();
}
void FullscreenModel::SetProgress(CGFloat progress) {
progress = std::min(static_cast<CGFloat>(1.0), progress);
progress = std::max(static_cast<CGFloat>(0.0), progress);
if (AreCGFloatsEqual(progress_, progress))
return;
progress_ = progress;
ScopedIncrementer progress_incrementer(&observer_callback_count_);
for (auto& observer : observers_) {
observer.FullscreenModelProgressUpdated(this);
}
}
void FullscreenModel::OnScrollViewSizeBroadcasted(CGSize scroll_view_size) {
SetScrollViewHeight(scroll_view_size.height);
}
void FullscreenModel::OnScrollViewContentSizeBroadcasted(CGSize content_size) {
SetContentHeight(content_size.height);
}
void FullscreenModel::OnScrollViewContentInsetBroadcasted(
UIEdgeInsets content_inset) {
SetTopContentInset(content_inset.top);
}
void FullscreenModel::OnContentScrollOffsetBroadcasted(CGFloat offset) {
SetYContentOffset(offset);
}
void FullscreenModel::OnScrollViewIsScrollingBroadcasted(bool scrolling) {
SetScrollViewIsScrolling(scrolling);
}
void FullscreenModel::OnScrollViewIsZoomingBroadcasted(bool zooming) {
SetScrollViewIsZooming(zooming);
}
void FullscreenModel::OnScrollViewIsDraggingBroadcasted(bool dragging) {
SetScrollViewIsDragging(dragging);
}
void FullscreenModel::OnCollapsedToolbarHeightBroadcasted(CGFloat height) {
SetCollapsedToolbarHeight(height);
}
void FullscreenModel::OnExpandedToolbarHeightBroadcasted(CGFloat height) {
SetExpandedToolbarHeight(height);
}
void FullscreenModel::OnBottomToolbarHeightBroadcasted(CGFloat height) {
SetBottomToolbarHeight(height);
}