ButtonStandardAdapter.cs source code in C# .NET

                        Code:
                         / FX-1434 / FX-1434 / 1.0 / untmp / whidbey / REDBITS / ndp / fx / src / WinForms / Managed / System / WinForms / ButtonInternal / ButtonStandardAdapter.cs / 1 / ButtonStandardAdapter.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Windows.Forms.ButtonInternal { 
    using System; 
    using System.Diagnostics;
    using System.Drawing; 
    using System.Windows.Forms.Internal;
    using System.Drawing.Drawing2D;
    using System.Drawing.Imaging;
    using System.Drawing.Text; 
    using System.Windows.Forms;
    using System.Windows.Forms.Layout; 
    using System.Windows.Forms.VisualStyles; 
    using System.Runtime.InteropServices;
    using System.ComponentModel; 
    using System.Diagnostics.CodeAnalysis;


    internal class ButtonStandardAdapter : ButtonBaseAdapter { 

        private const int borderWidth = 2; 
 
        internal ButtonStandardAdapter(ButtonBase control) : base(control) {}
 
        private PushButtonState DetermineState(bool up) {
            PushButtonState state = PushButtonState.Normal;

            if (!up) { 
                state = PushButtonState.Pressed;
            } 
            else if (Control.MouseIsOver) { 
                state = PushButtonState.Hot;
            } 
            else if (!Control.Enabled) {
                state = PushButtonState.Disabled;
            }
            else if (Control.Focused || Control.IsDefault) { 
                state = PushButtonState.Default;
            } 
 
            return state;
        } 

        internal override void PaintUp(PaintEventArgs e, CheckState state) {
            PaintWorker(e, true, state);
        } 

        internal override void PaintDown(PaintEventArgs e, CheckState state) { 
            PaintWorker(e, false, state); 
        }
 
        internal override void PaintOver(PaintEventArgs e, CheckState state) {
            PaintUp(e, state);
        }
 
        private void PaintThemedButtonBackground(PaintEventArgs e, Rectangle bounds, bool up) {
            PushButtonState pbState = DetermineState(up); 
 
            // First handle transparent case
 
            if (ButtonRenderer.IsBackgroundPartiallyTransparent(pbState)) {
                ButtonRenderer.DrawParentBackground(e.Graphics, bounds, Control);
            }
 
            // Now draw the actual themed background
 
            ButtonRenderer.DrawButton(e.Graphics, Control.ClientRectangle, false, pbState); 

            // Now overlay the background image or backcolor (the former overrides the latter), leaving a 
            // margin. We hardcode this margin for now since GetThemeMargins returns 0 all the
            // time.
            //HACK We need to see what's best here.  changing this to HACK because GetThemeMargins simply does not
            // work in some cases. 
            bounds.Inflate(-buttonBorderSize, -buttonBorderSize);
 
 
            //only paint if the user said not to use the themed backcolor.
            if (!Control.UseVisualStyleBackColor) { 
                bool painted = false;
                Color color = Control.BackColor;

                // Note: PaintEvent.HDC == 0 if GDI+ has used the HDC -- it wouldn't be safe for us 
                // to use it without enough bookkeeping to negate any performance gain of using GDI.
                if (color.A == 255 && e.HDC != IntPtr.Zero) { 
 
                    if (DisplayInformation.BitsPerPixel > 8) {
                        NativeMethods.RECT r = new NativeMethods.RECT(bounds.X, bounds.Y, bounds.Right, bounds.Bottom); 
                        SafeNativeMethods.FillRect(new HandleRef(e, e.HDC), ref r, new HandleRef(this, Control.BackColorBrush));
                        painted = true;
                    }
                } 

                if (!painted) { 
                    // don't paint anything from 100% transparent background 
                    //
                    if (color.A > 0) { 
                        if (color.A == 255) {
                            color = e.Graphics.GetNearestColor(color);
                        }
 
                        // Color has some transparency or we have no HDC, so we must
                        // fall back to using GDI+. 
                        // 
                        using (Brush brush = new SolidBrush(color)) {
                            e.Graphics.FillRectangle(brush, bounds); 
                        }
                    }
                }
            } 

            //This code is mostly taken from the non-themed rendering code path. 
            if (Control.BackgroundImage != null && !DisplayInformation.HighContrast) { 
                ControlPaint.DrawBackgroundImage(e.Graphics, Control.BackgroundImage, Color.Transparent, Control.BackgroundImageLayout, Control.ClientRectangle, bounds, Control.DisplayRectangle.Location, Control.RightToLeft);
            } 
        }

        void PaintWorker(PaintEventArgs e, bool up, CheckState state) {
            up = up && state == CheckState.Unchecked; 

            ColorData colors = PaintRender(e.Graphics).Calculate(); 
            LayoutData layout; 
            if (Application.RenderWithVisualStyles) {
                //don't have the text-pressed-down effect when we use themed painting 
                //this is for consistency with win32 app.
                layout = PaintLayout(e, true).Layout();
            }
            else { 
                layout = PaintLayout(e, up).Layout();
            } 
 
            Graphics g = e.Graphics;
 
            Button thisbutton = this.Control as Button;
            if (Application.RenderWithVisualStyles) {
                PaintThemedButtonBackground(e, Control.ClientRectangle, up);
            } 
            else {
                Brush backbrush = null; 
                if (state == CheckState.Indeterminate) { 
                    backbrush = CreateDitherBrush(colors.highlight, colors.buttonFace);
                } 

                try {
                    Rectangle bounds = Control.ClientRectangle;
                    if (up) { 
                        // We are going to draw a 2 pixel border
                        bounds.Inflate(-borderWidth, -borderWidth); // VS Whidbey #459900 
                    } 
                    else {
                        // We are going to draw a 1 pixel border. 
                        bounds.Inflate(-1, -1); // VS Whidbey #503487
                    }

                    PaintButtonBackground(e, bounds, backbrush); 
                }
                finally { 
                    if (backbrush != null) { 
                        backbrush.Dispose();
                        backbrush = null; 
                    }
                }
            }
 
            PaintImage(e, layout);
            //inflate the focus rectangle to be consistent with the behavior of Win32 app 
            if (Application.RenderWithVisualStyles) { 
                layout.focus.Inflate(1, 1);
            } 
            PaintField(e, layout, colors, colors.windowText, true);

            if (!Application.RenderWithVisualStyles) {
                Rectangle r = Control.ClientRectangle; 
                if (Control.IsDefault) {
                    r.Inflate(-1, -1); 
                } 

                DrawDefaultBorder(g, r, colors.windowFrame, this.Control.IsDefault); 

                if (up) {
                    Draw3DBorder(g, r, colors, up);
                } 
                else {
                    // contrary to popular belief, not Draw3DBorder(..., false); 
                    // 
                    ControlPaint.DrawBorder(g, r, colors.buttonShadow, ButtonBorderStyle.Solid);
                } 
            }
        }

        #region Layout 

        protected override LayoutOptions Layout(PaintEventArgs e) { 
            LayoutOptions layout = PaintLayout(e, /* up = */ false); 
            Debug.Assert(layout.GetPreferredSizeCore(LayoutUtils.MaxSize) == PaintLayout(e, /* up = */ true).GetPreferredSizeCore(LayoutUtils.MaxSize),
                "The state of up should not effect PreferredSize"); 
            return layout;
        }

        [SuppressMessage("Microsoft.Performance", "CA1801:AvoidUnusedParameters")]  // removed graphics, may have to put it back 
        private LayoutOptions PaintLayout(PaintEventArgs e, bool up) {
            LayoutOptions layout = CommonLayout(); 
            layout.textOffset        = !up; 
            layout.everettButtonCompat = !Application.RenderWithVisualStyles;
 
            return layout;
        }

        #endregion 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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ButtonStandardAdapter.cs source code in C# .NET

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