blob: 6ea29de25ac8536fd054b45af307ee58dc5cdebe [file] [log] [blame]
// 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 "content/common/input/gesture_event_stream_validator.h"
#include "base/logging.h"
#include "base/strings/stringprintf.h"
#include "content/common/input/web_input_event_traits.h"
#include "third_party/WebKit/public/web/WebInputEvent.h"
using blink::WebInputEvent;
namespace content {
GestureEventStreamValidator::GestureEventStreamValidator()
: scrolling_(false), pinching_(false), waiting_for_tap_end_(false) {
}
GestureEventStreamValidator::~GestureEventStreamValidator() {
}
bool GestureEventStreamValidator::Validate(const blink::WebGestureEvent& event,
std::string* error_msg) {
DCHECK(error_msg);
error_msg->clear();
if (!WebInputEvent::isGestureEventType(event.type)) {
error_msg->append(base::StringPrintf(
"Invalid gesture type: %s", WebInputEventTraits::GetName(event.type)));
}
switch (event.type) {
case WebInputEvent::GestureScrollBegin:
if (scrolling_)
error_msg->append("Scroll begin during scroll\n");
if (pinching_)
error_msg->append("Scroll begin during pinch\n");
scrolling_ = true;
break;
case WebInputEvent::GestureScrollUpdate:
if (!scrolling_)
error_msg->append("Scroll update outside of scroll\n");
break;
case WebInputEvent::GestureFlingStart:
if (event.sourceDevice == blink::WebGestureDeviceTouchscreen &&
!event.data.flingStart.velocityX &&
!event.data.flingStart.velocityY) {
error_msg->append("Zero velocity touchscreen fling\n");
}
if (!scrolling_)
error_msg->append("Fling start outside of scroll\n");
if (pinching_)
error_msg->append("Flinging while pinching\n");
scrolling_ = false;
break;
case WebInputEvent::GestureScrollEnd:
if (!scrolling_)
error_msg->append("Scroll end outside of scroll\n");
if (pinching_)
error_msg->append("Ending scroll while pinching\n");
scrolling_ = false;
break;
case WebInputEvent::GesturePinchBegin:
if (pinching_)
error_msg->append("Pinch begin during pinch\n");
pinching_ = true;
break;
case WebInputEvent::GesturePinchUpdate:
if (!pinching_)
error_msg->append("Pinch update outside of pinch\n");
break;
case WebInputEvent::GesturePinchEnd:
if (!pinching_)
error_msg->append("Pinch end outside of pinch\n");
pinching_ = false;
break;
case WebInputEvent::GestureTapDown:
if (waiting_for_tap_end_)
error_msg->append("Missing tap ending event before TapDown\n");
waiting_for_tap_end_ = true;
break;
case WebInputEvent::GestureTapUnconfirmed:
if (!waiting_for_tap_end_)
error_msg->append("Missing TapDown event before TapUnconfirmed\n");
break;
case WebInputEvent::GestureTapCancel:
if (!waiting_for_tap_end_)
error_msg->append("Missing TapDown event before TapCancel\n");
waiting_for_tap_end_ = false;
break;
case WebInputEvent::GestureTap:
if (!waiting_for_tap_end_)
error_msg->append("Missing TapDown event before Tap\n");
waiting_for_tap_end_ = false;
break;
case WebInputEvent::GestureDoubleTap:
// DoubleTap gestures may be synthetically inserted, and do not require a
// preceding TapDown.
waiting_for_tap_end_ = false;
break;
default:
break;
}
return error_msg->empty();
}
} // namespace content