Peter M. Groen / dali-demo

/*
 * 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.
 *
 */

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

// INTERNAL INCLUDES
#include "clipping-item-factory.h"
#include "item-view-orientation-constraint.h"

using namespace Dali;
using namespace Dali::Toolkit;

namespace
{
const char* const APPLICATION_TITLE("Clipping Controls");
const Vector3     APPLICATION_TITLE_PARENT_ORIGIN(0.5f, 0.03f, 0.5f); // Set the parent origin to a small percentage below the top (so the demo will scale for different resolutions).

const Vector3 ITEM_VIEW_LAYOUT_SIZE_SCALE(0.75f, 0.5f, 0.75f);
const float   ITEM_VIEW_BORDER_SIZE                       = 2.0f;
const float   ITEM_VIEW_MAXIMUM_ROTATION_IN_DEGREES       = 20.0f;
const float   ITEM_VIEW_LAYOUT_POSITION_CHANGE_MULTIPLIER = 3.0f;
const float   ITEM_VIEW_ROTATION_ANIMATION_TIME           = 0.2f;

const char* const BUTTON_LABEL("Toggle Clipping Mode");
} // unnamed namespace

/**
 * @brief Demonstrates the control clipping of a UI Control.
 *
 * When an Actor is set to clip its children, the renderers have to be added manually in order to specify what its children
 * need to clip to. UI Controls automate the creation of the renderers/visuals when they are set to clip their children.
 *
 * This example displays an item-view whose clipping mode is toggled without the need for adding any renderers to it.
 *
 * Additionally, a constraint is used to modify the item-view's orientation.
 */
class ClippingExample : public ConnectionTracker
{
public:
  /**
   * @brief Constructor.
   * @param[in] application A reference to the Application class.
   */
  ClippingExample(Application& application)
  : mApplication(application)
  {
    // Connect to the Application's Init signal
    mApplication.InitSignal().Connect(this, &ClippingExample::Create);
  }

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

    // Create a TextLabel for the application title.
    Toolkit::TextLabel label = Toolkit::TextLabel::New(APPLICATION_TITLE);
    label.SetProperty(Actor::Property::ANCHOR_POINT, AnchorPoint::TOP_CENTER);
    label.SetProperty(Actor::Property::PARENT_ORIGIN, APPLICATION_TITLE_PARENT_ORIGIN);
    label.SetProperty(Toolkit::TextLabel::Property::HORIZONTAL_ALIGNMENT, "CENTER");
    label.SetProperty(Toolkit::TextLabel::Property::VERTICAL_ALIGNMENT, "CENTER");
    label.SetProperty(Toolkit::TextLabel::Property::TEXT_COLOR, Color::WHITE);
    window.Add(label);

    // Create an item-view which clips its children.
    mItemView = ItemView::New(mClippingItemFactory);
    mItemView.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::CENTER);
    mItemView.SetProperty(Actor::Property::ANCHOR_POINT, AnchorPoint::CENTER);
    mItemView.SetProperty(Actor::Property::CLIPPING_MODE, ClippingMode::CLIP_CHILDREN); // Enable clipping. No need to create any renderers.
    window.Add(mItemView);

    // Create a Spiral Layout and add it to the Item View.
    mItemView.AddLayout(*DefaultItemLayout::New(DefaultItemLayout::SPIRAL));
    window.GetRootLayer().SetProperty(Layer::Property::BEHAVIOR, Layer::LAYER_3D); // The item-view spiral layout requires Layer 3D behaviour.

    // Calculate the size we would like our item-view layout to be, and then activate the layout.
    const Vector2 windowSize = window.GetSize();
    const Vector3 itemViewLayoutSize(ITEM_VIEW_LAYOUT_SIZE_SCALE.x * windowSize.x, ITEM_VIEW_LAYOUT_SIZE_SCALE.y * windowSize.y, ITEM_VIEW_LAYOUT_SIZE_SCALE.z * windowSize.x);
    mItemView.ActivateLayout(0, itemViewLayoutSize, 0.0f);

    // Connect to the scroll started and completed signals to apply orientation constraints & animations.
    mItemView.ScrollStartedSignal().Connect(this, &ClippingExample::ScrollStarted);
    mItemView.ScrollCompletedSignal().Connect(this, &ClippingExample::ScrollCompleted);

    // Create a constraint for the item-view which we apply when we start scrolling and remove when we stop.
    mItemViewOrientationConstraint = Constraint::New<Quaternion>(mItemView, Actor::Property::ORIENTATION, ItemViewOrientationConstraint(ITEM_VIEW_MAXIMUM_ROTATION_IN_DEGREES, ITEM_VIEW_LAYOUT_POSITION_CHANGE_MULTIPLIER));
    mItemViewOrientationConstraint.AddSource(LocalSource(ItemView::Property::LAYOUT_POSITION));

    // Create a border around item-view (as item-view is clipping its children, we should NOT add this as a child of item-view).
    Control border = Control::New();
    border.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::CENTER);
    border.SetProperty(Actor::Property::ANCHOR_POINT, AnchorPoint::CENTER);
    border.SetProperty(Control::Property::BACKGROUND,
                       Property::Map().Add(Toolkit::Visual::Property::TYPE, Visual::BORDER).Add(BorderVisual::Property::COLOR, Color::WHITE).Add(BorderVisual::Property::SIZE, 2.0f).Add(BorderVisual::Property::ANTI_ALIASING, true));
    border.SetProperty(Actor::Property::SIZE, Vector3(itemViewLayoutSize.x + ITEM_VIEW_BORDER_SIZE * 2.0f, itemViewLayoutSize.y + ITEM_VIEW_BORDER_SIZE * 2.0f, itemViewLayoutSize.z + ITEM_VIEW_BORDER_SIZE * 2.0f));
    window.Add(border);

    // Constrain the border's orientation to the orientation of item-view.
    Constraint constraint = Constraint::New<Quaternion>(border, Actor::Property::ORIENTATION, EqualToConstraint());
    constraint.AddSource(Source(mItemView, Actor::Property::ORIENTATION));
    constraint.Apply();

    // Create a button to toggle the clipping mode
    PushButton button = Toolkit::PushButton::New();
    button.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::BOTTOM_CENTER);
    button.SetProperty(Actor::Property::ANCHOR_POINT, AnchorPoint::BOTTOM_CENTER);
    button.SetResizePolicy(ResizePolicy::FILL_TO_PARENT, Dimension::WIDTH);
    button.SetResizePolicy(ResizePolicy::USE_NATURAL_SIZE, Dimension::HEIGHT);
    button.SetProperty(Actor::Property::DRAW_MODE, DrawMode::OVERLAY_2D);
    button.SetProperty(Button::Property::LABEL, BUTTON_LABEL);
    button.ClickedSignal().Connect(this, &ClippingExample::OnButtonClicked);
    window.Add(button);
  }

  /**
   * @brief Called when the item-view starts to scroll.
   *
   * Here we want to apply the item-view constraint.
   */
  void ScrollStarted(const Vector2& /* currentScrollPosition */)
  {
    mItemViewOrientationConstraint.Apply();
  }

  /**
   * @brief Called when the item-view scrolling completes.
   *
   * Here we remove the item-view orientation constraint and perform an animation to return the item-view back to base-rotation.
   */
  void ScrollCompleted(const Vector2& /* currentScrollPosition */)
  {
    Animation animation = Animation::New(ITEM_VIEW_ROTATION_ANIMATION_TIME);
    animation.AnimateTo(Property(mItemView, Actor::Property::ORIENTATION), Quaternion(Degree(0.0f), Vector3::XAXIS), AlphaFunction::EASE_IN_SINE);
    animation.Play();

    mItemViewOrientationConstraint.Remove();
  }

  /**
   * @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_KEY_ESCAPE) || IsKey(event, DALI_KEY_BACK))
      {
        mApplication.Quit();
      }
    }
  }

  /**
   * @brief Called when the button is clicked.
   *
   * Will use this to toggle between the clipping modes.
   * @param[in] button The button that has been clicked.
   */
  bool OnButtonClicked(Toolkit::Button button)
  {
    if(mItemView)
    {
      ClippingMode::Type currentMode = static_cast<ClippingMode::Type>(mItemView.GetProperty(Actor::Property::CLIPPING_MODE).Get<int>());
      mItemView.SetProperty(Actor::Property::CLIPPING_MODE, (currentMode == ClippingMode::CLIP_CHILDREN) ? ClippingMode::DISABLED : ClippingMode::CLIP_CHILDREN);
    }
    return true;
  }

  // Data

  Application&        mApplication;                   ///< Reference to the application class.
  ItemView            mItemView;                      ///< The item view which whose children we would like to clip.
  ClippingItemFactory mClippingItemFactory;           ///< The ItemFactory used to create our items.
  Constraint          mItemViewOrientationConstraint; ///< The constraint used to control the orientation of item-view.
};

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