/*
 * Copyright (c) 2020 Samsung Electronics Co., Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#include <dali-toolkit/dali-toolkit.h>
#include <dali/devel-api/actors/actor-devel.h>

using namespace Dali;
using namespace Dali::Toolkit;

namespace
{
const float COLOR_ANIMATION_DURATION(5.0f);
const float OPACITY_ANIMATION_DURATION(1.0f);
} // unnamed namespace

/**
 * @brief An example that shows how to use property notifications.
 *
 * - Creates a text label and sets its text color to black.
 * - Animates the text color of a text label to red.
 * - Sets up a property notification so that we are informed when the color is 50% red.
 * - When we are notified, we start a new animation which animates the text label to transparent.
 */
class PropertyNotificationController : public ConnectionTracker
{
public:
  /**
   * @brief Constructor.
   * @param[in] application A reference to the Application class.
   */
  PropertyNotificationController(Application& application)
  : mApplication(application)
  {
    // Connect to the Application's Init signal
    mApplication.InitSignal().Connect(this, &PropertyNotificationController::Create);
  }

  /**
   * @brief Called to initialise the application content
   * @param[in] application A reference to the Application class.
   */
  void Create(Application& application)
  {
    // Set the window background color and connect to the window's key signal to allow Back and Escape to exit.
    Window window = application.GetWindow();
    window.SetBackgroundColor(Color::WHITE);
    window.KeyEventSignal().Connect(this, &PropertyNotificationController::OnKeyEvent);

    // Create a text label and set the text color to black
    mTextLabel = TextLabel::New("Black to Red Animation\nNew opacity animation at 50% Red");
    mTextLabel.SetProperty(Actor::Property::ANCHOR_POINT, AnchorPoint::CENTER);
    mTextLabel.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::CENTER);
    mTextLabel.SetProperty(TextLabel::Property::MULTI_LINE, true);
    mTextLabel.SetProperty(TextLabel::Property::HORIZONTAL_ALIGNMENT, "CENTER");
    mTextLabel.SetProperty(TextLabel::Property::TEXT_COLOR, Color::BLACK);
    window.Add(mTextLabel);

    // Create an animation and animate the text color to red
    Animation animation = Animation::New(COLOR_ANIMATION_DURATION);
    animation.AnimateTo(Property(mTextLabel, TextLabel::Property::TEXT_COLOR), Color::RED);
    animation.Play();

    // Set up a property notification so we are notified when the red component of the text-color reaches 50%
    PropertyNotification notification = mTextLabel.AddPropertyNotification(TextLabel::Property::TEXT_COLOR_RED, GreaterThanCondition(0.5f));
    notification.NotifySignal().Connect(this, &PropertyNotificationController::RedComponentNotification);
  }

  /**
   * @brief Called when any key event is received
   *
   * Will use this to quit the application if Back or the Escape key is received
   * @param[in] event The key event information
   */
  void OnKeyEvent(const KeyEvent& event)
  {
    if(event.GetState() == KeyEvent::DOWN)
    {
      if(IsKey(event, Dali::DALI_KEY_ESCAPE) || IsKey(event, Dali::DALI_KEY_BACK))
      {
        mApplication.Quit();
      }
    }
  }

  /**
   * @brief Called when the property notification condition is met.
   *
   * In our case, it's when the red component is greater than 50%.
   * Will use this notification to animate the opacity of the text-label to transparent.
   */
  void RedComponentNotification(PropertyNotification& /* source */)
  {
    Animation animation = Animation::New(OPACITY_ANIMATION_DURATION);
    animation.AnimateTo(Property(mTextLabel, Actor::Property::OPACITY), 0.0f);
    animation.Play();
  }

private:
  Application& mApplication;
  TextLabel    mTextLabel;
};

int DALI_EXPORT_API main(int argc, char** argv)
{
  Application                    application = Application::New(&argc, &argv);
  PropertyNotificationController test(application);
  application.MainLoop();
  return 0;
}