// Licensed to the .NET Foundation under one or more agreements. // The .NET Foundation licenses this file to you under the MIT license. // See the LICENSE file in the project root for more information. using System.Globalization; using System.Windows.Data; using MS.Internal; #if RIBBON_IN_FRAMEWORK namespace System.Windows.Controls.Ribbon.Primitives #else namespace Microsoft.Windows.Controls.Ribbon.Primitives #endif { /// <summary> /// Data binding converter to handle the visibility of repeat buttons in scrolling ribbon. /// </summary> public sealed class RibbonScrollButtonVisibilityConverter : IMultiValueConverter { /// <summary> /// Convert a value. Called when moving a value from source to target. /// </summary> /// <param name="values">values as produced by source binding</param> /// <param name="targetType">target type</param> /// <param name="parameter">converter parameter</param> /// <param name="culture">culture information</param> /// <returns> /// Converted value. /// /// System.Windows.DependencyProperty.UnsetValue may be returned to indicate that /// the converter produced no value and that the fallback (if available) /// or default value should be used instead. /// /// Binding.DoNothing may be returned to indicate that the binding /// should not transfer the value or use the fallback or default value. /// </returns> public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture) { // // Parameter Validation // if (parameter == null || values == null || values.Length != 4 || values[0] is not Visibility || values[1] is not double || values[2] is not double || values[3] is not double) { return DependencyProperty.UnsetValue; } if (parameter is not double && parameter is not string) { return DependencyProperty.UnsetValue; } // // Conversion // // If the scroll bar should be visible, then so should our buttons Visibility computedScrollBarVisibility = (Visibility)values[0]; if (computedScrollBarVisibility == Visibility.Visible) { double target; string parameterString = parameter as string; if (parameterString != null) { target = Double.Parse(parameterString, NumberFormatInfo.InvariantInfo); } else { target = (double)parameter; } double offset = (double)values[1]; double extent = (double)values[2]; double viewport = (double)values[3]; // If the extent is less than or close to viewport, then // the scroll buttons should be collapsed if (DoubleUtil.LessThanOrClose(extent, viewport)) { return Visibility.Collapsed; } // Calculate the percent so that we can see if we are near the edge of the range double percent = Math.Min(100.0, Math.Max(0.0, (offset * 100.0 / (extent - viewport)))); if (DoubleUtil.AreClose(percent, target)) { // We are at the end of the range, so no need for this button to be shown return Visibility.Collapsed; } return Visibility.Visible; } return Visibility.Collapsed; } /// <summary> /// Not Supported /// </summary> /// <param name="value">value, as produced by target</param> /// <param name="targetTypes">target types</param> /// <param name="parameter">converter parameter</param> /// <param name="culture">culture information</param> /// <returns>Nothing</returns> public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture) { return new object[] { Binding.DoNothing }; } } } |