source: branches/2929_PrioritizedGrammarEnumeration/HeuristicLab.ExtLibs/HeuristicLab.AvalonEdit/5.0.1/AvalonEdit-5.0.1/CodeCompletion/CompletionWindow.cs @ 15990

// Copyright (c) 2014 AlphaSierraPapa for the SharpDevelop Team
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy of this
// software and associated documentation files (the "Software"), to deal in the Software
// without restriction, including without limitation the rights to use, copy, modify, merge,
// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
// to whom the Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in all copies or
// substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

using System;
using System.Diagnostics;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Data;
using System.Windows.Input;
using System.Windows.Threading;
using ICSharpCode.AvalonEdit.Document;
using ICSharpCode.AvalonEdit.Editing;

namespace ICSharpCode.AvalonEdit.CodeCompletion
{
  /// <summary>
  /// The code completion window.
  /// </summary>
  public class CompletionWindow : CompletionWindowBase
  {
    readonly CompletionList completionList = new CompletionList();
    ToolTip toolTip = new ToolTip();
    
    /// <summary>
    /// Gets the completion list used in this completion window.
    /// </summary>
    public CompletionList CompletionList {
      get { return completionList; }
    }
    
    /// <summary>
    /// Creates a new code completion window.
    /// </summary>
    public CompletionWindow(TextArea textArea) : base(textArea)
    {
      // keep height automatic
      this.CloseAutomatically = true;
      this.SizeToContent = SizeToContent.Height;
      this.MaxHeight = 300;
      this.Width = 175;
      this.Content = completionList;
      // prevent user from resizing window to 0x0
      this.MinHeight = 15;
      this.MinWidth = 30;
      
      toolTip.PlacementTarget = this;
      toolTip.Placement = PlacementMode.Right;
      toolTip.Closed += toolTip_Closed;
      
      AttachEvents();
    }
    
    #region ToolTip handling
    void toolTip_Closed(object sender, RoutedEventArgs e)
    {
      // Clear content after tooltip is closed.
      // We cannot clear is immediately when setting IsOpen=false
      // because the tooltip uses an animation for closing.
      if (toolTip != null)
        toolTip.Content = null;
    }
    
    void completionList_SelectionChanged(object sender, SelectionChangedEventArgs e)
    {
      var item = completionList.SelectedItem;
      if (item == null)
        return;
      object description = item.Description;
      if (description != null) {
        string descriptionText = description as string;
        if (descriptionText != null) {
          toolTip.Content = new TextBlock  {
            Text = descriptionText,
            TextWrapping = TextWrapping.Wrap
          };
        } else {
          toolTip.Content = description;
        }
        toolTip.IsOpen = true;
      } else {
        toolTip.IsOpen = false;
      }
    }
    #endregion
    
    void completionList_InsertionRequested(object sender, EventArgs e)
    {
      Close();
      // The window must close before Complete() is called.
      // If the Complete callback pushes stacked input handlers, we don't want to pop those when the CC window closes.
      var item = completionList.SelectedItem;
      if (item != null)
        item.Complete(this.TextArea, new AnchorSegment(this.TextArea.Document, this.StartOffset, this.EndOffset - this.StartOffset), e);
    }
    
    void AttachEvents()
    {
      this.completionList.InsertionRequested += completionList_InsertionRequested;
      this.completionList.SelectionChanged += completionList_SelectionChanged;
      this.TextArea.Caret.PositionChanged += CaretPositionChanged;
      this.TextArea.MouseWheel += textArea_MouseWheel;
      this.TextArea.PreviewTextInput += textArea_PreviewTextInput;
    }
    
    /// <inheritdoc/>
    protected override void DetachEvents()
    {
      this.completionList.InsertionRequested -= completionList_InsertionRequested;
      this.completionList.SelectionChanged -= completionList_SelectionChanged;
      this.TextArea.Caret.PositionChanged -= CaretPositionChanged;
      this.TextArea.MouseWheel -= textArea_MouseWheel;
      this.TextArea.PreviewTextInput -= textArea_PreviewTextInput;
      base.DetachEvents();
    }
    
    /// <inheritdoc/>
    protected override void OnClosed(EventArgs e)
    {
      base.OnClosed(e);
      if (toolTip != null) {
        toolTip.IsOpen = false;
        toolTip = null;
      }
    }
    
    /// <inheritdoc/>
    protected override void OnKeyDown(KeyEventArgs e)
    {
      base.OnKeyDown(e);
      if (!e.Handled) {
        completionList.HandleKey(e);
      }
    }
    
    void textArea_PreviewTextInput(object sender, TextCompositionEventArgs e)
    {
      e.Handled = RaiseEventPair(this, PreviewTextInputEvent, TextInputEvent,
                                 new TextCompositionEventArgs(e.Device, e.TextComposition));
    }
    
    void textArea_MouseWheel(object sender, MouseWheelEventArgs e)
    {
      e.Handled = RaiseEventPair(GetScrollEventTarget(),
                                 PreviewMouseWheelEvent, MouseWheelEvent,
                                 new MouseWheelEventArgs(e.MouseDevice, e.Timestamp, e.Delta));
    }
    
    UIElement GetScrollEventTarget()
    {
      if (completionList == null)
        return this;
      return completionList.ScrollViewer ?? completionList.ListBox ?? (UIElement)completionList;
    }
    
    /// <summary>
    /// Gets/Sets whether the completion window should close automatically.
    /// The default value is true.
    /// </summary>
    public bool CloseAutomatically { get; set; }
    
    /// <inheritdoc/>
    protected override bool CloseOnFocusLost {
      get { return this.CloseAutomatically; }
    }
    
    /// <summary>
    /// When this flag is set, code completion closes if the caret moves to the
    /// beginning of the allowed range. This is useful in Ctrl+Space and "complete when typing",
    /// but not in dot-completion.
    /// Has no effect if CloseAutomatically is false.
    /// </summary>
    public bool CloseWhenCaretAtBeginning { get; set; }
    
    void CaretPositionChanged(object sender, EventArgs e)
    {
      int offset = this.TextArea.Caret.Offset;
      if (offset == this.StartOffset) {
        if (CloseAutomatically && CloseWhenCaretAtBeginning) {
          Close();
        } else {
          completionList.SelectItem(string.Empty);
        }
        return;
      }
      if (offset < this.StartOffset || offset > this.EndOffset) {
        if (CloseAutomatically) {
          Close();
        }
      } else {
        TextDocument document = this.TextArea.Document;
        if (document != null) {
          completionList.SelectItem(document.GetText(this.StartOffset, offset - this.StartOffset));
        }
      }
    }
  }
}