Class: QML::ImageProvider

Inherits:
Object
  • Object
show all
Defined in:
lib/qml/image_provider.rb

Overview

ImageProvider is used to provide images manually to QML.

QML requests images to ImageProviders when you use “image:” URL scheme (like “image://my_image_provider/foo.png”) in source specification of Image elements.

Examples:

class MyImageProvider < QML::ImageProvider
  def request(req)
    Thread.new do
      image_data = load_image_data()
      req.finish(image_data)
    end
  end
end
QML.engine.add_image_provider(MyImageProvider.new)

See Also:

Defined Under Namespace

Classes: Callback, Request

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ ImageProvider

Returns a new instance of ImageProvider.



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# File 'lib/qml/image_provider.rb', line 53

def initialize
  @callback = Callback.new(self)
  @qt_image_provider = Plugins.core.createImageProvider(@callback)
  @qt_image_provider.prefer_managed false
end

Instance Attribute Details

#qt_image_provider ⇒ Object (readonly)

Returns the value of attribute qt_image_provider.



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# File 'lib/qml/image_provider.rb', line 51

def qt_image_provider
  @qt_image_provider
end

Instance Method Details

#request(req) ⇒ Object

This method is abstract.

Implement this method to handle image requests from QML.

Call QML::ImageProvider::Request#finish to finish image loading. Image loading should be done asynchnorously because this method is called within the event loop.

Parameters:



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# File 'lib/qml/image_provider.rb', line 67

def request(req)
  fail ::NotImplementedError
end