FontFamily.cs source code in C# .NET

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/ DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / CommonUI / System / Drawing / Advanced / FontFamily.cs / 1 / FontFamily.cs

                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

/*************************************************************************\ 
* 
* Copyright (c) 1998-1999, Microsoft Corp.  All Rights Reserved.
* 
* Module Name:
*
*   fontfamily.cs
* 
* Abstract:
* 
*   COM+ wrapper for GDI+ FontFamily object 
*
* Revision History: 
*
*   10/04/1999 [...]
*       Created it.
* 
\**************************************************************************/
 
 
/*
* font family object (sdkinc\GDIplusFontFamily.h) 
*/

namespace System.Drawing {
    using System.Text; 
    using System.Runtime.InteropServices;
    using System.Diagnostics; 
    using System; 
    using System.ComponentModel;
    using Microsoft.Win32; 
    using System.Globalization;
    using System.Drawing.Text;
    using System.Drawing;
    using System.Drawing.Internal; 

    /** 
     * Represent a FontFamily object 
     */
    ///  
    /// 
    ///    Abstracts a group of type faces having a
    ///    similar basic design but having certain variation in styles.
    ///  
    public sealed class FontFamily : MarshalByRefObject, IDisposable {
        private const int LANG_NEUTRAL = 0; 
        private IntPtr nativeFamily; 
        private bool createDefaultOnFail;
 
#if DEBUG
        private static object lockObj = new object();
        private static int idCount = 0;
        private int id; 
#endif
 
        ///  
        ///     Sets the GDI+ native family.
        ///  
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2106:SecureAsserts")]
        private void SetNativeFamily( IntPtr family )
        {
            Debug.Assert( this.nativeFamily == IntPtr.Zero, "Setting GDI+ native font family when already initialized." ); 
            Debug.Assert( family != IntPtr.Zero, "Setting GDI+ native font family to null." );
 
            this.nativeFamily = family; 
#if DEBUG
            lock(lockObj){ 
                id = ++idCount;
            }
#endif
        } 

        /// 
        ///     Internal constructor to initialize the native GDI+ font to an existing one. 
        ///     Used to create generic fonts and by FontCollection class.
        /// 
        internal FontFamily(IntPtr family)
        {
            SetNativeFamily( family );
        } 

        ///  
        ///  
        ///    
        ///       Initializes a new instance of the  
        ///       class with the specified name.
        ///
        ///       The  parameter determines how errors are
        ///       handled when creating a font based on a font family that does not exist on the 
        ///       end user's system at run time. If this parameter is true, then a fall-back font
        ///       will always be used instead. If this parameter is false, an exception will be thrown. 
        ///     
        /// 
        internal FontFamily(string name, bool createDefaultOnFail) 
        {
            this.createDefaultOnFail = createDefaultOnFail;
            CreateFontFamily(name, null);
        } 

        ///  
        ///  
        ///    
        ///       Initializes a new instance of the  
        ///       class with the specified name.
        ///    
        /// 
        public FontFamily(string name) 
        {
            CreateFontFamily(name, null); 
        } 

        ///  
        /// 
        ///    Initializes a new instance of the 
        ///    class in the specified  and with the specified name.
        ///  
        public FontFamily(string name, FontCollection fontCollection)
        { 
            CreateFontFamily(name, fontCollection); 
        }
 
        /// 
        ///     Creates the native font family object.
        ///     Note: GDI+ creates singleton font family objects (from the corresponding font file) and reference count them.
        ///  
        private void CreateFontFamily(string name, FontCollection fontCollection)
        { 
            IntPtr fontfamily = IntPtr.Zero; 
            IntPtr nativeFontCollection = (fontCollection == null) ? IntPtr.Zero : fontCollection.nativeFontCollection;
 
            int status = SafeNativeMethods.Gdip.GdipCreateFontFamilyFromName(name, new HandleRef(fontCollection, nativeFontCollection), out fontfamily);

            if (status != SafeNativeMethods.Gdip.Ok)
            { 
                if (createDefaultOnFail)
                { 
                    fontfamily = GetGdipGenericSansSerif();  // This throws if failed. 
                }
                else 
                {
                    // Special case this incredibly common error message to give more information
                    if (status == SafeNativeMethods.Gdip.FontFamilyNotFound)
                    { 
                        throw new ArgumentException(SR.GetString(SR.GdiplusFontFamilyNotFound, name));
                    } 
                    else if (status == SafeNativeMethods.Gdip.NotTrueTypeFont) 
                    {
                        throw new ArgumentException(SR.GetString(SR.GdiplusNotTrueTypeFont, name)); 
                    }
                    else
                    {
                        throw SafeNativeMethods.Gdip.StatusException(status); 
                    }
                } 
            } 

            SetNativeFamily( fontfamily ); 
        }

        /// 
        ///  
        ///    Initializes a new instance of the 
        ///    class from the specified generic font family. 
        ///  
        public FontFamily(GenericFontFamilies genericFamily) {
            IntPtr fontfamily = IntPtr.Zero; 
            int status;

            switch (genericFamily) {
                case GenericFontFamilies.Serif: 
                {
                    status = SafeNativeMethods.Gdip.GdipGetGenericFontFamilySerif(out fontfamily); 
                    break; 
                }
                case GenericFontFamilies.SansSerif: 
                {
                    status = SafeNativeMethods.Gdip.GdipGetGenericFontFamilySansSerif(out fontfamily);
                    break;
                } 
                case GenericFontFamilies.Monospace:
                default: 
                { 
                    status = SafeNativeMethods.Gdip.GdipGetGenericFontFamilyMonospace(out fontfamily);
                    break; 
                }
            }

            if (status != SafeNativeMethods.Gdip.Ok) 
                throw SafeNativeMethods.Gdip.StatusException(status);
 
            SetNativeFamily( fontfamily ); 
        }
 
        /// 
        /// 
        ///    
        ///       Allows an object to free resources before the object is reclaimed by the 
        ///       Garbage Collector ().
        ///     
        ///  
        ~FontFamily()
        { 
            Dispose(false);
        }

        ///  
        ///     The GDI+ native font family.  It is shared by all FontFamily objects with same family name.
        ///  
        internal IntPtr NativeFamily 
        {
            get 
            {
                //Debug.Assert( this.nativeFamily != IntPtr.Zero, "this.nativeFamily == IntPtr.Zero." );
                return this.nativeFamily;
            } 
        }
 
        // The managed wrappers do not expose a Clone method, as it's really nothing more 
        // than AddRef (it doesn't copy the underlying GpFont), and in a garbage collected
        // world, that's not very useful. 

        /// 
        /// 
        ///    [To be supplied.] 
        /// 
        public override bool Equals(object obj) 
        { 

            if (obj == this) 
                return true;

            FontFamily ff = obj as FontFamily;
 
            if (ff == null)
                return false; 
 
            // We can safely use the ptr to the native GDI+ FontFamily because it is common to
            // all objects of the same family (singleton RO object). 
            return ff.NativeFamily == this.NativeFamily;
        }

        ///  
        /// 
        ///    Converts this  to a 
        ///    human-readable string. 
        /// 
        public override string ToString() { 
            return string.Format(CultureInfo.CurrentCulture, "[{0}: Name={1}]", GetType().Name, this.Name);
        }

        ///  
        /// 
        ///    Gets a hash code for this . 
        ///  
        public override int GetHashCode() {
            return this.GetName(LANG_NEUTRAL).GetHashCode(); 
        }

        private static int CurrentLanguage {
            get { 
                return System.Globalization.CultureInfo.CurrentUICulture.LCID;
            } 
        } 

        ///  
        /// 
        ///    Disposes of this .
        /// 
        public void Dispose() { 
            Dispose(true);
            GC.SuppressFinalize(this); 
        } 

        void Dispose(bool disposing) 
        {
            if (this.nativeFamily != IntPtr.Zero)
            {
                try 
                {
#if DEBUG 
                    int status = 
#endif
                    SafeNativeMethods.Gdip.GdipDeleteFontFamily(new HandleRef(this, this.nativeFamily)); 
#if DEBUG
                    Debug.Assert(status == SafeNativeMethods.Gdip.Ok, "GDI+ returned an error status: " + status.ToString(CultureInfo.InvariantCulture));
#endif
                } 
                catch (Exception ex)
                { 
                    if (ClientUtils.IsCriticalException(ex)) 
                    {
                        throw; 
                    }

                    Debug.Fail("Exception thrown during Dispose: " + ex.ToString());
                } 
                finally
                { 
                    this.nativeFamily = IntPtr.Zero; 
                }
            } 
        }

        /// 
        ///  
        ///    Gets the name of this .
        ///  
        public String Name 
        {
            get 
            {
                return GetName(CurrentLanguage);
            }
        } 

        ///  
        ///  
        ///    
        ///       Retuns the name of this  in 
        ///       the specified language.
        ///    
        /// 
        public String GetName(int language) 
        {
            // LF_FACESIZE is 32 
            StringBuilder name = new StringBuilder(32); 

            int status = SafeNativeMethods.Gdip.GdipGetFamilyName(new HandleRef(this, this.NativeFamily), name, language); 

            if (status != SafeNativeMethods.Gdip.Ok)
                throw SafeNativeMethods.Gdip.StatusException(status);
 
            return name.ToString();
        } 
 

        ///  
        /// 
        ///    Returns an array that contains all of the
        ///  objects associated with the current graphics
        ///    context. 
        /// 
        public static FontFamily[] Families { 
            get { 
                IntPtr screenDC = UnsafeNativeMethods.GetDC(NativeMethods.NullHandleRef);
                FontFamily[] result = null; 
                try {
                    Graphics graphics = Graphics.FromHdcInternal(screenDC);
                    try {
                        result = GetFamilies(graphics); 
                    }
                    finally { 
                        graphics.Dispose(); 
                    }
                } 
                finally {
                    UnsafeNativeMethods.ReleaseDC(NativeMethods.NullHandleRef, new HandleRef(null, screenDC));
                }
                return result; 
            }
        } 
 
         /// 
        ///  
        ///    
        ///       Gets a generic SansSerif .
        ///    
        ///  
        public static FontFamily GenericSansSerif {
            get { 
                return new FontFamily(GetGdipGenericSansSerif()); 
            }
        } 

        private static IntPtr GetGdipGenericSansSerif() {
            IntPtr fontfamily = IntPtr.Zero;
 
            int status = SafeNativeMethods.Gdip.GdipGetGenericFontFamilySansSerif(out fontfamily);
 
            if (status != SafeNativeMethods.Gdip.Ok) 
                throw SafeNativeMethods.Gdip.StatusException(status);
 
            return fontfamily;
        }

        ///  
        /// 
        ///    Gets a generic Serif . 
        ///  
        public static FontFamily GenericSerif {
            get { 
                return new FontFamily(GetNativeGenericSerif());
            }
        }
 
        private static IntPtr GetNativeGenericSerif() {
            IntPtr fontfamily = IntPtr.Zero; 
 
            int status = SafeNativeMethods.Gdip.GdipGetGenericFontFamilySerif(out fontfamily);
 
            if (status != SafeNativeMethods.Gdip.Ok)
                throw SafeNativeMethods.Gdip.StatusException(status);

            return fontfamily; 
        }
 
        ///  
        /// 
        ///    Gets a generic monospace . 
        /// 
        public static FontFamily GenericMonospace {
            get {
                return new FontFamily(GetNativeGenericMonospace()); 
            }
        } 
 
        private static IntPtr GetNativeGenericMonospace() {
            IntPtr fontfamily = IntPtr.Zero; 

            int status = SafeNativeMethods.Gdip.GdipGetGenericFontFamilyMonospace(out fontfamily);

            if (status != SafeNativeMethods.Gdip.Ok) 
                throw SafeNativeMethods.Gdip.StatusException(status);
 
            return fontfamily; 
        }
 
        // No longer support in FontFamily
        // Obsolete API and need to be removed later
        //
        ///  
        /// 
        ///     
        ///       Returns an array that contains all of the  objects associated with 
        ///       the specified graphics context.
        ///     
        /// 
        public static FontFamily[] GetFamilies(Graphics graphics) {
            if (graphics == null)
                throw new ArgumentNullException("graphics"); 

            return new InstalledFontCollection().Families; 
        } 

        ///  
        /// 
        ///    Indicates whether the specified  is
        ///    available.
        ///  
        public bool IsStyleAvailable(FontStyle style) {
            int bresult; 
 
            int status = SafeNativeMethods.Gdip.GdipIsStyleAvailable(new HandleRef(this, this.NativeFamily), style, out bresult);
 
            if (status != SafeNativeMethods.Gdip.Ok)
                throw SafeNativeMethods.Gdip.StatusException(status);

            return bresult != 0; 
        }
 
        ///  
        /// 
        ///    Gets the size of the Em square for the 
        ///    specified style in font design units.
        /// 
        public int GetEmHeight(FontStyle style) {
            int result = 0; 

            int status = SafeNativeMethods.Gdip.GdipGetEmHeight(new HandleRef(this, this.NativeFamily), style, out result); 
 
            if (status != SafeNativeMethods.Gdip.Ok)
                throw SafeNativeMethods.Gdip.StatusException(status); 

            return result;
        }
 

        ///  
        ///  
        ///    
        ///       Returns the ascender metric for Windows. 
        ///    
        /// 
        public int GetCellAscent(FontStyle style) {
            int result = 0; 

            int status = SafeNativeMethods.Gdip.GdipGetCellAscent(new HandleRef(this, this.NativeFamily), style, out result); 
 
            if (status != SafeNativeMethods.Gdip.Ok)
                throw SafeNativeMethods.Gdip.StatusException(status); 

            return result;
        }
 
        /// 
        ///  
        ///     
        ///       Returns the descender metric for Windows.
        ///     
        /// 
        public int GetCellDescent(FontStyle style) {
            int result = 0;
 
            int status = SafeNativeMethods.Gdip.GdipGetCellDescent(new HandleRef(this, this.NativeFamily), style, out result);
 
            if (status != SafeNativeMethods.Gdip.Ok) 
                throw SafeNativeMethods.Gdip.StatusException(status);
 
            return result;
        }

        ///  
        /// 
        ///    Returns the distance between two 
        ///    consecutive lines of text for this  with the specified . 
        /// 
        public int GetLineSpacing(FontStyle style) { 
            int result = 0;

            int status = SafeNativeMethods.Gdip.GdipGetLineSpacing(new HandleRef(this, this.NativeFamily), style, out result);
 
            if (status != SafeNativeMethods.Gdip.Ok)
                throw SafeNativeMethods.Gdip.StatusException(status); 
 
            return result;
        } 
    }
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007. 
// Copyright (c) Microsoft Corporation. All rights reserved.
                        

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