private void OnCustomStyleResolved(CustomStyleResolvedEvent evt)
{
ICustomStyle styles = evt.customStyle;
if (styles.TryGetValue(_background_image_property, out Texture2D value))
{
// if there is no background image create it
if (_backgroundImage == null)
{
_backgroundImage = TiledImage.CreateBackground(value);
_backgroundImage.AddToClassList("viewport-background");
hierarchy.Add(_backgroundImage);
_backgroundImage.SendToBack();
_backgroundImage.StretchToParentSize();
_contentContainer.RegisterCallback <GeometryChangedEvent>(e => UpdateBackground());
}
else
{
_backgroundImage.SetTexture(value);
}
UpdateBackground();
}
}
// ######################## INITS ######################## //
#region CONSTRUCTORS
public ColorSlider()
{
// load styles
styleSheets.Add(Resources.Load <StyleSheet>("ColorSlider_styles"));
styleSheets.Add(Resources.Load <StyleSheet>("Styles"));
// create and initialize gradient texture
_gradientTexture = new Texture2D(2, 1, TextureFormat.RGBA32, false, QualitySettings.activeColorSpace == ColorSpace.Gamma)
{
hideFlags = HideFlags.HideAndDontSave,
wrapMode = TextureWrapMode.Clamp,
filterMode = FilterMode.Bilinear,
alphaIsTransparency = true
};
_gradientTexture.SetPixel(0, 0, Color.clear);
_gradientTexture.SetPixel(1, 0, Color.clear);
_gradientTexture.Apply();
// set up alpha background
TiledImage background = TiledImage.CreateBackground(Resources.Load <Texture2D>("Images/AlphaCheckerboard"));
background.AddToClassList("unity-base-slider--horizontal");
background.AddToClassList("unity-base-slider__tracker");
background.style.backgroundColor = Color.clear;
// set as child of the first element in the hierarchy of the slider
IEnumerator <VisualElement> children = Children().GetEnumerator();
children.MoveNext();
children.Current.Add(background);
children.Dispose();
background.SendToBack();
// add a field for the value to be displayed
IntegerField valueField = new IntegerField();
valueField.AddToClassList(UssClasses.FILL_HEIGHT);
valueField.AddToClassList("color-slider-value-field");
Add(valueField);
// set up the background of the slider (unity calls this the tracker). This is what holds the gradient texture
VisualElement tracker = this.Q("unity-tracker");
tracker.AddToClassList(UssClasses.FULL);
tracker.AddToClassList(UssClasses.NO_SLICE);
tracker.style.backgroundImage = _gradientTexture;
// set up the handle
VisualElement handle = this.Q("unity-dragger");
handle.AddToClassList("color-slider-handle");
handle.AddToClassList(UssClasses.FILL_HEIGHT);
handle.style.position = Position.Absolute;
#if UNITY_2019_3_OR_NEWER
// remove handle border
VisualElement handleBorder = this.Q("unity-dragger-border");
handleBorder.visible = false;
#endif
// set up the label
labelElement.AddToClassList("color-slider-label");
labelElement.AddToClassList(UssClasses.FILL_HEIGHT);
// register callbacks
this.RegisterValueChangedCallback(evt => valueField.SetValueWithoutNotify((int)evt.newValue));
valueField.RegisterValueChangedCallback(evt =>
{
float clampedValue = Mathf.Clamp(evt.newValue, lowValue, highValue);
valueField.SetValueWithoutNotify((int)clampedValue);
value = clampedValue;
});
}