File size: 4,706 Bytes
8c763fb
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;
using System.Windows;
using System.Windows.Input;

namespace Microsoft.Management.UI.Internal
{
    internal enum LogicalDirection
    {
        None,
        Left,
        Right
    }

    internal static class KeyboardHelp
    {
        /// <summary>
        /// Gets the logical direction for a key, taking into account RTL settings.
        /// </summary>
        /// <param name="element">The element to get FlowDirection from.</param>
        /// <param name="key">The key pressed.</param>
        /// <returns>The logical direction.</returns>
        public static LogicalDirection GetLogicalDirection(DependencyObject element, Key key)
        {
            Debug.Assert(element != null, "element not null");

            bool rightToLeft = IsElementRightToLeft(element);

            switch (key)
            {
                case Key.Right:
                    if (rightToLeft)
                    {
                        return LogicalDirection.Left;
                    }
                    else
                    {
                        return LogicalDirection.Right;
                    }

                case Key.Left:
                    if (rightToLeft)
                    {
                        return LogicalDirection.Right;
                    }
                    else
                    {
                        return LogicalDirection.Left;
                    }

                default:
                    return LogicalDirection.None;
            }
        }

        /// <summary>
        /// Gets the focus direction for a key, taking into account RTL settings.
        /// </summary>
        /// <param name="element">The element to get FlowDirection from.</param>
        /// <param name="key">The key pressed.</param>
        /// <returns>The focus direction.</returns>
        public static FocusNavigationDirection GetNavigationDirection(DependencyObject element, Key key)
        {
            Debug.Assert(element != null, "element not null");
            Debug.Assert(IsFlowDirectionKey(key));

            bool rightToLeft = IsElementRightToLeft(element);

            switch (key)
            {
                case Key.Right:
                    if (rightToLeft)
                    {
                        return FocusNavigationDirection.Left;
                    }
                    else
                    {
                        return FocusNavigationDirection.Right;
                    }

                case Key.Left:
                    if (rightToLeft)
                    {
                        return FocusNavigationDirection.Right;
                    }
                    else
                    {
                        return FocusNavigationDirection.Left;
                    }

                case Key.Down:
                    return FocusNavigationDirection.Down;
                case Key.Up:
                    return FocusNavigationDirection.Up;
                default:
                    Debug.Fail("Non-direction key specified");
                    return FocusNavigationDirection.First;
            }
        }

        /// <summary>
        /// Determines if the control key is pressed.
        /// </summary>
        /// <returns>True if a control is pressed.</returns>
        public static bool IsControlPressed()
        {
            if ((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control)
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        /// <summary>
        /// Determines if the key is a navigation key.
        /// </summary>
        /// <param name="key">The key pressed.</param>
        /// <returns>True if the key is a navigation key.</returns>
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]
        private static bool IsFlowDirectionKey(Key key)
        {
            switch (key)
            {
                case Key.Right:
                case Key.Left:
                case Key.Down:
                case Key.Up:
                    return true;
                default:
                    return false;
            }
        }

        private static bool IsElementRightToLeft(DependencyObject element)
        {
            FlowDirection flowDirection = FrameworkElement.GetFlowDirection(element);
            bool rightToLeft = flowDirection == FlowDirection.RightToLeft;
            return rightToLeft;
        }
    }
}