examples/image-view-alpha-blending/image-view-alpha-blending-example.cpp

   1 /*
   2  * Copyright (c) 2022 Samsung Electronics Co., Ltd.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  *
  16  */
  17
  18 #include <dali-toolkit/dali-toolkit.h>
  19 #include <dali-toolkit/devel-api/image-loader/texture-manager.h>
  20 #include <dali-toolkit/devel-api/visuals/visual-properties-devel.h>
  21
  22 using namespace Dali;
  23
  24 namespace
  25 {
  26 const char* const IMAGE_PATH(DEMO_IMAGE_DIR "gallery-large-20.jpg");
  27 }
  28
  29 class ImageViewAlphaBlendApp : public ConnectionTracker
  30 {
  31 public:
  32   ImageViewAlphaBlendApp(Application& application)
  33   : mApplication(application),
  34     mIndex(0u)
  35   {
  36     // Connect to the Application's Init signal
  37     mApplication.InitSignal().Connect(this, &ImageViewAlphaBlendApp::Create);
  38   }
  39
  40   ~ImageViewAlphaBlendApp()
  41   {
  42     // Nothing to do here;
  43   }
  44
  45 private:
  46   // The Init signal is received once (only) during the Application lifetime
  47   void Create(Application& application)
  48   {
  49     // Get a handle to the window
  50     Window window = application.GetWindow();
  51     window.KeyEventSignal().Connect(this, &ImageViewAlphaBlendApp::OnKeyEvent);
  52     const Vector2 windowSize = window.GetSize();
  53     const bool portraitOrientation = windowSize.width < windowSize.height;
  54     const Property::Index positionProperty = portraitOrientation ? Actor::Property::POSITION_Y : Actor::Property::POSITION_X;
  55
  56     auto  green0    = Vector4(0.f, 1.f, 0.f, 0.25f);
  57     auto  green1    = Vector4(0.f, 0.25f, 0.f, 0.25f);
  58     auto  redGreen0 = CreateTexture(Color::RED, green0);
  59     auto  redGreen1 = CreateTexture(Color::RED, green1);
  60     float imageSize = 512.f;
  61
  62     Toolkit::ImageView imageView0 = CreateImageView(IMAGE_PATH);
  63     imageView0.SetProperty(Actor::Property::SIZE, Vector2(imageSize, imageSize));
  64     imageView0.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::CENTER);
  65     imageView0.SetProperty(positionProperty, -imageSize * 0.5f);
  66     window.Add(imageView0);
  67     Toolkit::ImageView imageView1 = CreateImageView(redGreen0);
  68     imageView1.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::CENTER);
  69     imageView1.SetProperty(Actor::Property::SIZE, Vector2(imageSize, imageSize));
  70     imageView0.Add(imageView1);
  71
  72     Toolkit::ImageView imageView2 = CreateImageView(IMAGE_PATH);
  73     imageView2.SetProperty(Actor::Property::SIZE, Vector2(imageSize, imageSize));
  74     imageView2.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::CENTER);
  75     imageView2.SetProperty(positionProperty, imageSize * 0.5f);
  76     window.Add(imageView2);
  77     Toolkit::ImageView imageView3 = CreateImageView(redGreen1);
  78     imageView3.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::CENTER);
  79     imageView3.SetProperty(Actor::Property::SIZE, Vector2(imageSize, imageSize));
  80     imageView2.Add(imageView3);
  81
  82     imageView2.SetProperty(Toolkit::ImageView::Property::PRE_MULTIPLIED_ALPHA, true);
  83     imageView3.SetProperty(Toolkit::ImageView::Property::PRE_MULTIPLIED_ALPHA, true);
  84
  85     Animation animation = Animation::New(10.f);
  86     animation.AnimateTo(Property(imageView0, Actor::Property::COLOR), Vector4(1.0f, 1.0f, 1.0f, 0.0f), AlphaFunction::BOUNCE, TimePeriod(2.f, 8.f));
  87     animation.AnimateTo(Property(imageView2, Actor::Property::COLOR), Vector4(1.0f, 1.0f, 1.0f, 0.0f), AlphaFunction::BOUNCE, TimePeriod(2.f, 8.f));
  88     animation.SetLooping(true);
  89     animation.Play();
  90   }
  91
  92   void OnKeyEvent(const KeyEvent& event)
  93   {
  94     if(event.GetState() == KeyEvent::DOWN)
  95     {
  96       if(IsKey(event, Dali::DALI_KEY_ESCAPE) || IsKey(event, Dali::DALI_KEY_BACK))
  97       {
  98         mApplication.Quit();
  99       }
 100     }
 101   }
 102
 103   std::string CreateTexture(const Vector4& color1, const Vector4& color2)
 104   {
 105     const auto width       = 2u;
 106     const auto height      = 1u;
 107     auto       size        = width * height * 4;
 108     auto       pixelBuffer = new unsigned char[size];
 109     pixelBuffer[0]         = 0xFF * color1.x;
 110     pixelBuffer[1]         = 0xFF * color1.y;
 111     pixelBuffer[2]         = 0xFF * color1.z;
 112     pixelBuffer[3]         = 0xFF * color1.w;
 113     pixelBuffer[4]         = 0xFF * color2.x;
 114     pixelBuffer[5]         = 0xFF * color2.y;
 115     pixelBuffer[6]         = 0xFF * color2.z;
 116     pixelBuffer[7]         = 0xFF * color2.w;
 117
 118     auto pixelData = PixelData::New(pixelBuffer, size, width, height, Pixel::RGBA8888, PixelData::ReleaseFunction::DELETE_ARRAY);
 119     auto texture   = Texture::New(TextureType::TEXTURE_2D, Pixel::RGBA8888, width, height);
 120     texture.Upload(pixelData);
 121
 122     return Toolkit::TextureManager::AddTexture(texture);
 123   }
 124
 125   template<typename TextT>
 126   Toolkit::ImageView CreateImageView(TextT&& filename)
 127   {
 128     auto imageView = Toolkit::ImageView::New();
 129
 130     Property::Map propertyMap;
 131     propertyMap.Insert(Toolkit::ImageVisual::Property::URL, std::forward<TextT>(filename));
 132     propertyMap.Insert(Toolkit::Visual::Property::TYPE, Toolkit::Visual::IMAGE);
 133     propertyMap.Insert(Toolkit::DevelVisual::Property::VISUAL_FITTING_MODE, Toolkit::DevelVisual::FILL);
 134     imageView.SetProperty(Toolkit::ImageView::Property::IMAGE, propertyMap);
 135
 136     return imageView;
 137   }
 138
 139 private:
 140   Application& mApplication;
 141   unsigned int mIndex;
 142 };
 143
 144 int DALI_EXPORT_API main(int argc, char** argv)
 145 {
 146   Application            application = Application::New(&argc, &argv);
 147   ImageViewAlphaBlendApp test(application);
 148   application.MainLoop();
 149   return 0;
 150 }