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// Copyright 2014 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 "athena/wm/bezel_controller.h"
#include "ui/aura/window.h"
#include "ui/events/event_handler.h"
#include "ui/gfx/display.h"
#include "ui/gfx/geometry/point_conversions.h"
#include "ui/gfx/screen.h"
#include "ui/wm/core/coordinate_conversion.h"
namespace athena {
namespace {
// Using bezel swipes, the first touch that is registered is usually within
// 5-10 pixels from the edge, but sometimes as far as 29 pixels away.
// So setting this width fairly high for now.
const float kBezelWidth = 20.0f;
const float kScrollDeltaNone = 0;
bool ShouldProcessGesture(ui::EventType event_type) {
return event_type == ui::ET_GESTURE_SCROLL_UPDATE ||
event_type == ui::ET_GESTURE_SCROLL_BEGIN ||
event_type == ui::ET_GESTURE_BEGIN ||
event_type == ui::ET_GESTURE_END;
}
gfx::Display GetDisplay(aura::Window* window) {
gfx::Screen* screen = gfx::Screen::GetScreenFor(window);
return screen->GetDisplayNearestWindow(window);
}
float GetDistance(const gfx::PointF& location,
aura::Window* window,
BezelController::Bezel bezel) {
DCHECK(bezel == BezelController::BEZEL_LEFT ||
bezel == BezelController::BEZEL_RIGHT);
// Convert location from window coordinates to screen coordinates.
gfx::Point point_in_screen(gfx::ToRoundedPoint(location));
wm::ConvertPointToScreen(window, &point_in_screen);
return bezel == BezelController::BEZEL_LEFT
? point_in_screen.x()
: point_in_screen.x() - GetDisplay(window).bounds().width();
}
} // namespace
BezelController::BezelController(aura::Window* container)
: container_(container),
state_(NONE),
scroll_bezel_(BEZEL_NONE),
scroll_target_(NULL),
left_right_delegate_(NULL) {
}
void BezelController::SetState(BezelController::State state) {
// Use SetState(State, float) if |state| is one of the BEZEL_SCROLLING states.
DCHECK_NE(state, BEZEL_SCROLLING_TWO_FINGERS);
DCHECK_NE(state, BEZEL_SCROLLING_ONE_FINGER);
SetState(state, kScrollDeltaNone);
}
void BezelController::SetState(BezelController::State state,
float scroll_delta) {
if (!left_right_delegate_ || state == state_)
return;
if (state == BEZEL_SCROLLING_TWO_FINGERS)
left_right_delegate_->ScrollBegin(scroll_bezel_, scroll_delta);
else if (state_ == BEZEL_SCROLLING_TWO_FINGERS)
left_right_delegate_->ScrollEnd();
state_ = state;
if (state == NONE) {
scroll_bezel_ = BEZEL_NONE;
scroll_target_ = NULL;
}
}
// Only implemented for LEFT and RIGHT bezels ATM.
BezelController::Bezel BezelController::GetBezel(const gfx::PointF& location) {
int screen_width = GetDisplay(container_).bounds().width();
if (location.x() < kBezelWidth) {
return BEZEL_LEFT;
} else if (location.x() > screen_width - kBezelWidth) {
return BEZEL_RIGHT;
} else {
return BEZEL_NONE;
}
}
void BezelController::OnGestureEvent(ui::GestureEvent* event) {
// TODO(mfomitchev): Currently we aren't retargetting or consuming any of the
// touch events. This means that content can prevent the generation of gesture
// events and two-finger scroll won't work. Possible solution to this problem
// is hosting our own gesture recognizer or retargetting touch events at the
// bezel.
if (!left_right_delegate_)
return;
ui::EventType type = event->type();
if (!ShouldProcessGesture(type))
return;
if (scroll_target_ && event->target() != scroll_target_)
return;
const gfx::PointF& event_location = event->location_f();
const ui::GestureEventDetails& event_details = event->details();
int num_touch_points = event_details.touch_points();
float scroll_delta = kScrollDeltaNone;
if (scroll_bezel_ != BEZEL_NONE) {
aura::Window* target_window = static_cast<aura::Window*>(event->target());
scroll_delta = GetDistance(event_location, target_window, scroll_bezel_);
}
if (type == ui::ET_GESTURE_BEGIN) {
if (num_touch_points > 2) {
SetState(IGNORE_CURRENT_SCROLL);
return;
}
BezelController::Bezel event_bezel = GetBezel(event->location_f());
switch (state_) {
case NONE:
scroll_bezel_ = event_bezel;
scroll_target_ = event->target();
if (event_bezel != BEZEL_LEFT && event_bezel != BEZEL_RIGHT)
SetState(IGNORE_CURRENT_SCROLL);
else
SetState(BEZEL_GESTURE_STARTED);
break;
case IGNORE_CURRENT_SCROLL:
break;
case BEZEL_GESTURE_STARTED:
case BEZEL_SCROLLING_ONE_FINGER:
DCHECK_EQ(num_touch_points, 2);
DCHECK(scroll_target_);
DCHECK_NE(scroll_bezel_, BEZEL_NONE);
if (event_bezel != scroll_bezel_) {
SetState(IGNORE_CURRENT_SCROLL);
return;
}
if (state_ == BEZEL_SCROLLING_ONE_FINGER)
SetState(BEZEL_SCROLLING_TWO_FINGERS);
break;
case BEZEL_SCROLLING_TWO_FINGERS:
// Should've exited above
NOTREACHED();
break;
}
} else if (type == ui::ET_GESTURE_END) {
if (state_ == NONE)
return;
CHECK(scroll_target_);
if (num_touch_points == 1) {
SetState(NONE);
} else {
SetState(IGNORE_CURRENT_SCROLL);
}
} else if (type == ui::ET_GESTURE_SCROLL_BEGIN) {
DCHECK(state_ == IGNORE_CURRENT_SCROLL || state_ == BEZEL_GESTURE_STARTED);
if (state_ != BEZEL_GESTURE_STARTED)
return;
if (num_touch_points == 1) {
SetState(BEZEL_SCROLLING_ONE_FINGER, scroll_delta);
return;
}
DCHECK_EQ(num_touch_points, 2);
SetState(BEZEL_SCROLLING_TWO_FINGERS, scroll_delta);
if (left_right_delegate_->CanScroll())
event->SetHandled();
} else if (type == ui::ET_GESTURE_SCROLL_UPDATE) {
if (state_ != BEZEL_SCROLLING_TWO_FINGERS)
return;
left_right_delegate_->ScrollUpdate(scroll_delta);
if (left_right_delegate_->CanScroll())
event->SetHandled();
}
}
} // namespace athena
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