// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt) // This code is distributed under the GNU LGPL (for details please see \doc\license.txt) using System; using System.Collections.Generic; using System.Diagnostics; using System.Windows; using System.Windows.Documents; using System.Windows.Input; using System.Windows.Media; using System.Windows.Media.TextFormatting; using System.Windows.Navigation; namespace ICSharpCode.AvalonEdit.Rendering { /// <summary> /// VisualLineElement that represents a piece of text and is a clickable link. /// </summary> public class VisualLineLinkText : VisualLineText { /// <summary> /// Gets/Sets the URL that is navigated to when the link is clicked. /// </summary> public Uri NavigateUri { get; set; } /// <summary> /// Gets/Sets the window name where the URL will be opened. /// </summary> public string TargetName { get; set; } /// <summary> /// Gets/Sets whether the user needs to press Control to click the link. /// The default value is true. /// </summary> public bool RequireControlModifierForClick { get; set; } /// <summary> /// Creates a visual line text element with the specified length. /// It uses the <see cref="ITextRunConstructionContext.VisualLine"/> and its /// <see cref="VisualLineElement.RelativeTextOffset"/> to find the actual text string. /// </summary> public VisualLineLinkText(VisualLine parentVisualLine, int length) : base(parentVisualLine, length) { this.RequireControlModifierForClick = true; } /// <inheritdoc/> public override TextRun CreateTextRun(int startVisualColumn, ITextRunConstructionContext context) { this.TextRunProperties.SetForegroundBrush(context.TextView.LinkTextForegroundBrush); this.TextRunProperties.SetBackgroundBrush(context.TextView.LinkTextBackgroundBrush); this.TextRunProperties.SetTextDecorations(TextDecorations.Underline); return base.CreateTextRun(startVisualColumn, context); } /// <summary> /// Gets whether the link is currently clickable. /// </summary> /// <remarks>Returns true when control is pressed; or when /// <see cref="RequireControlModifierForClick"/> is disabled.</remarks> protected bool LinkIsClickable() { if (NavigateUri == null) return false; if (RequireControlModifierForClick) return (Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control; else return true; } /// <inheritdoc/> protected internal override void OnQueryCursor(QueryCursorEventArgs e) { if (LinkIsClickable()) { e.Handled = true; e.Cursor = Cursors.Hand; } } /// <inheritdoc/> [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1031:DoNotCatchGeneralExceptionTypes", Justification = "I've seen Process.Start throw undocumented exceptions when the mail client / web browser is installed incorrectly")] protected internal override void OnMouseDown(MouseButtonEventArgs e) { if (e.ChangedButton == MouseButton.Left && !e.Handled && LinkIsClickable()) { RequestNavigateEventArgs args = new RequestNavigateEventArgs(this.NavigateUri, this.TargetName); args.RoutedEvent = Hyperlink.RequestNavigateEvent; FrameworkElement element = e.Source as FrameworkElement; if (element != null) { // allow user code to handle the navigation request element.RaiseEvent(args); } if (!args.Handled) { try { Process.Start(this.NavigateUri.ToString()); } catch { // ignore all kinds of errors during web browser start } } e.Handled = true; } } /// <inheritdoc/> protected override VisualLineText CreateInstance(int length) { return new VisualLineLinkText(ParentVisualLine, length) { NavigateUri = this.NavigateUri, TargetName = this.TargetName, RequireControlModifierForClick = this.RequireControlModifierForClick }; } } }
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