GradientStopSlider
The GradientStopSlider control allows for adding, changing, and removing the various gradient stops within a GradientBrush, such as a LinearGradientBrush.
Usage
The slider will display a thumb for each GradientStop in the gradient brush. Each stop consists of an offset and Color pair.
Thumbs can be dragged to adjust their offsets and the color for the selected thumb can be changed. When dragging a thumb far above or below the slider, it will turn semi-transparent meaning that it will be removed if it is released at that location. Double click an empty area of the slider track to insert a new thumb.
The GradientStopSlider.ActiveBrush is the property that you apply a two-way binding to whichever Brush-based property that you wish to adjust using the slider.
You also need to add a two-way binding to the SelectedColor property that binds to an external control for altering the color of the selected stop. Any one of the coloring picking controls in this product can be used for this purpose.
Stop Add/Remove Capabilities
The CanAddStops and CanRemoveStops properties can be used to restrict whether stops can be added to or removed from the gradient brush. They are both true by default.
Track Height
The TrackHeight property sets the height of the track, which is the area in which the actual gradient brush is rendered.
Commands for External Buttons
There are several properties that return ICommand and can be utilized by external buttons or menu items:
Simply bind the Command property of an external button or menu item to the appropriate slider property to have them interact with the control.
Reusing Brushes
By default, the brush instance will generally be reused when a gradient stop is added/updated/removed. But this prevents bindings to the ActiveBrush property from updating when using value converters. The CanReuseBrush property can be set to false to force a new brush to be created any time a gradient stop is added/updated/removed, which works around those issues.