//------------------------------------------------------------------------------
// <copyright file="TextBoxRenderer.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>                                                                
//------------------------------------------------------------------------------
namespace System.Windows.Forms {
 
    using System;
    using System.Drawing;
    using System.Diagnostics.CodeAnalysis;
    using System.Windows.Forms.Internal;
    using System.Windows.Forms.VisualStyles;
    using Microsoft.Win32;
 
 
    /// <include file='doc\TextBoxRenderer.uex' path='docs/doc[@for="TextBoxRenderer"]/*' />
    /// <devdoc>
    ///    <para>
    ///       This is a rendering class for the TextBox control.
    ///    </para>
    /// </devdoc>
    public sealed class TextBoxRenderer {
 
        //Make this per-thread, so that different threads can safely use these methods.
        [ThreadStatic]
        private static VisualStyleRenderer visualStyleRenderer = null;
        private static readonly VisualStyleElement TextBoxElement = VisualStyleElement.TextBox.TextEdit.Normal;
 
        //cannot instantiate
        private TextBoxRenderer() {
        }
 
        /// <include file='doc\TextBoxRenderer.uex' path='docs/doc[@for="TextBoxRenderer.IsSupported"]/*' />
        /// <devdoc>
        ///    <para>
        ///       Returns true if this class is supported for the current OS and user/application settings, 
        ///       otherwise returns false.
        ///    </para>
        /// </devdoc>
        public static bool IsSupported {
            get {
                return VisualStyleRenderer.IsSupported; // no downlevel support
            }
        }
 
        private static void DrawBackground(Graphics g, Rectangle bounds, TextBoxState state) {
            visualStyleRenderer.DrawBackground(g, bounds);
            if (state != TextBoxState.Disabled) {
                Color windowColor = visualStyleRenderer.GetColor(ColorProperty.FillColor);
                if (windowColor != SystemColors.Window) {
                    Rectangle fillRect = visualStyleRenderer.GetBackgroundContentRectangle(g, bounds);
                    //then we need to re-fill the background.
                    using(SolidBrush brush = new SolidBrush(SystemColors.Window)) {
                        g.FillRectangle(brush, fillRect);
                    }
                }
            }
        }
 
        /// <include file='doc\TextBoxRenderer.uex' path='docs/doc[@for="TextBoxRenderer.DrawTextBox"]/*' />
        /// <devdoc>
        ///    <para>
        ///       Renders a TextBox control.
        ///    </para>
        /// </devdoc>
        [
            SuppressMessage("Microsoft.Design", "CA1011:ConsiderPassingBaseTypesAsParameters") // Using Graphics instead of IDeviceContext intentionally
        ]
        public static void DrawTextBox(Graphics g, Rectangle bounds, TextBoxState state) {
            InitializeRenderer((int)state);
            DrawBackground(g, bounds, state);
        }
 
        /// <include file='doc\TextBoxRenderer.uex' path='docs/doc[@for="TextBoxRenderer.DrawTextBox1"]/*' />
        /// <devdoc>
        ///    <para>
        ///       Renders a TextBox control.
        ///    </para>
        /// </devdoc>
        public static void DrawTextBox(Graphics g, Rectangle bounds, string textBoxText, Font font, TextBoxState state) {
            DrawTextBox(g, bounds, textBoxText, font, TextFormatFlags.TextBoxControl, state);
        }
 
        /// <include file='doc\TextBoxRenderer.uex' path='docs/doc[@for="TextBoxRenderer.DrawTextBox1"]/*' />
        /// <devdoc>
        ///    <para>
        ///       Renders a TextBox control.
        ///    </para>
        /// </devdoc>
        public static void DrawTextBox(Graphics g, Rectangle bounds, string textBoxText, Font font, Rectangle textBounds, TextBoxState state) {
            DrawTextBox(g, bounds, textBoxText, font, textBounds, TextFormatFlags.TextBoxControl, state);
        }
 
        /// <include file='doc\TextBoxRenderer.uex' path='docs/doc[@for="TextBoxRenderer.DrawTextBox2"]/*' />
        /// <devdoc>
        ///    <para>
        ///       Renders a TextBox control.
        ///    </para>
        /// </devdoc>
        public static void DrawTextBox(Graphics g, Rectangle bounds, string textBoxText, Font font, TextFormatFlags flags, TextBoxState state) {
            InitializeRenderer((int)state);
            Rectangle textBounds = visualStyleRenderer.GetBackgroundContentRectangle(g, bounds);
            textBounds.Inflate(-2, -2);
            DrawTextBox(g, bounds, textBoxText, font, textBounds, flags, state);
        }
 
        /// <include file='doc\TextBoxRenderer.uex' path='docs/doc[@for="TextBoxRenderer.DrawTextBox2"]/*' />
        /// <devdoc>
        ///    <para>
        ///       Renders a TextBox control.
        ///    </para>
        /// </devdoc>
        [
            SuppressMessage("Microsoft.Design", "CA1011:ConsiderPassingBaseTypesAsParameters") // Using Graphics instead of IDeviceContext intentionally
        ]
        public static void DrawTextBox(Graphics g, Rectangle bounds, string textBoxText, Font font, Rectangle textBounds, TextFormatFlags flags, TextBoxState state) {
            InitializeRenderer((int)state);
 
            DrawBackground(g, bounds, state);
            Color textColor = visualStyleRenderer.GetColor(ColorProperty.TextColor);
            TextRenderer.DrawText(g, textBoxText, font, textBounds, textColor, flags);
        }
 
 
        private static void InitializeRenderer(int state) {
            if (visualStyleRenderer == null) {
                visualStyleRenderer = new VisualStyleRenderer(TextBoxElement.ClassName, TextBoxElement.Part, state);
            }
            else {
                visualStyleRenderer.SetParameters(TextBoxElement.ClassName, TextBoxElement.Part, state);
            }
        }
    }
}