chrome/browser/vr/content_input_delegate.cc

// 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.

#include "chrome/browser/vr/content_input_delegate.h"

#include "base/callback_helpers.h"
#include "base/time/time.h"
#include "chrome/browser/vr/platform_input_handler.h"

namespace vr {

ContentInputDelegate::ContentInputDelegate() {}

ContentInputDelegate::ContentInputDelegate(PlatformInputHandler* input_handler)
    : PlatformUiInputDelegate(input_handler) {}

ContentInputDelegate::~ContentInputDelegate() = default;

void ContentInputDelegate::OnFocusChanged(bool focused) {
  // The call below tells the renderer to clear the focused element. Note that
  // we don't need to do anything when focused is true because the renderer
  // already knows about the focused element.
  if (!focused)
    input_handler()->ClearFocusedElement();
}

void ContentInputDelegate::OnWebInputEdited(const EditedText& info,
                                            bool commit) {
  if (!input_handler())
    return;

  last_keyboard_edit_ = info;

  if (commit) {
    input_handler()->SubmitWebInput();
    return;
  }

  input_handler()->OnWebInputEdited(info.GetDiff());
}

void ContentInputDelegate::OnSwapContents(int new_content_id) {
  content_id_ = new_content_id;
}

void ContentInputDelegate::SendGestureToTarget(
    std::unique_ptr<InputEvent> event) {
  if (!event || !input_handler() || ContentGestureIsLocked(event->type()))
    return;

  input_handler()->ForwardEventToContent(std::move(event), content_id_);
}

bool ContentInputDelegate::ContentGestureIsLocked(InputEvent::Type type) {
  // TODO (asimjour) create a new HoverEnter event when we swap webcontents and
  // pointer is on the content quad.
  if (type == InputEvent::kScrollBegin || type == InputEvent::kHoverMove ||
      type == InputEvent::kButtonDown || type == InputEvent::kHoverEnter)
    locked_content_id_ = content_id_;

  return locked_content_id_ != content_id_;
}

void ContentInputDelegate::OnWebInputIndicesChanged(
    int selection_start,
    int selection_end,
    int composition_start,
    int composition_end,
    base::OnceCallback<void(const TextInputInfo&)> callback) {
  // The purpose of this method is to determine if we need to query content for
  // the text surrounding the currently focused web input field.

  // If the changed indices match with that from the last keyboard edit, then
  // this is called in response to the user entering text using the keyboard, so
  // we already know the text and don't need to ask content for it.
  TextInputInfo i = last_keyboard_edit_.current;
  if (i.selection_start == selection_start &&
      i.selection_end == selection_end &&
      i.composition_start == composition_start &&
      i.composition_end == composition_end) {
    base::ResetAndReturn(&callback).Run(i);
    return;
  }

  // If the changed indices are the same as the previous ones, this is probably
  // called as a side-effect of us requesting the text state below, so it's safe
  // to ignore this update. If this is not called as a side-effect of us
  // requesting the text state below, and the indices just happen to match the
  // previous state, it's still okay to ignore this update. Consider the
  // following scenario: 1) State after last request for web input state:
  //     This is a test|
  // 2) JS on the page changed the web input state to:
  //     This blah test|
  // In this case, 2) will trigger this function and we'll ignore it. The next
  // time user types something, we'll calculate the diff from our stale version
  // of the web input state, but because we're committing the delta between the
  // previous and the current keyboard state, the update to content will still
  // be correct. That is, even if the keyboard works with the incorrect version
  // of the text state, the end result is still correct from the user's point of
  // view. This is also how android IME works (it only requests text state when
  // the indices actually change).
  i = pending_text_input_info_;
  if (pending_text_request_state_ != kNoPendingRequest &&
      i.selection_start == selection_start &&
      i.selection_end == selection_end &&
      i.composition_start == composition_start &&
      i.composition_end == composition_end) {
    pending_text_request_state_ = kNoPendingRequest;
    return;
  }

  // The indices changed and we need to query the update state.
  pending_text_input_info_.selection_start = selection_start;
  pending_text_input_info_.selection_end = selection_end;
  pending_text_input_info_.composition_start = composition_start;
  pending_text_input_info_.composition_end = composition_end;
  update_state_callbacks_.emplace(std::move(callback));
  pending_text_request_state_ = kRequested;
  input_handler()->RequestWebInputText(base::BindOnce(
      &ContentInputDelegate::OnWebInputTextChanged, base::Unretained(this)));
}

void ContentInputDelegate::ClearTextInputState() {
  pending_text_request_state_ = kNoPendingRequest;
  pending_text_input_info_ = TextInputInfo();
  last_keyboard_edit_ = EditedText();
}

void ContentInputDelegate::OnWebInputTextChanged(const base::string16& text) {
  pending_text_input_info_.text = text;
  DCHECK(!update_state_callbacks_.empty());

  pending_text_request_state_ = kResponseReceived;
  auto update_state_callback = std::move(update_state_callbacks_.front());
  update_state_callbacks_.pop();
  base::ResetAndReturn(&update_state_callback).Run(pending_text_input_info_);
}

}  // namespace vr