C# Backends.ImageDescription类代码示例

		public void SetImage (ImageDescription image)
		{
			Gtk.ImageMenuItem it = item as Gtk.ImageMenuItem;
			if (it == null)
				return;
			if (!image.IsNull) {
				if (defImage == null)
					item.StateChanged += ImageMenuItemStateChanged;
				defImage = image;
				selImage = new ImageDescription {
					Backend = image.Backend,
					Size = image.Size,
					Alpha = image.Alpha,
					Styles = image.Styles.Add ("sel")
				};
				var img = new ImageBox (context, image);
				img.ShowAll ();
				it.Image = img;
				GtkWorkarounds.ForceImageOnMenuItem (it);
			} else {
				if (defImage.HasValue) {
					item.StateChanged -= ImageMenuItemStateChanged;
					defImage = selImage = null;
				}
				it.Image = null;
			}
		}

 public override object Create(ImageDescription img)
 {
     NSImage nimg = img.ToNSImage ();
     return new ImagePatternInfo () {
         Image = nimg
     };
 }

 void Draw(object ctx, Rectangle bounds, ImageDescription idesc, Toolkit toolkit)
 {
     var c = new Context (ctx, toolkit);
     if (idesc.Styles != StyleSet.Empty)
         c.SetStyles (idesc.Styles);
     c.Reset (null);
     c.Save ();
     c.GlobalAlpha = idesc.Alpha;
     OnDraw (c, bounds);
     c.Restore ();
 }

		public void SetImage (ImageDescription image)
		{
			Gtk.ImageMenuItem it = item as Gtk.ImageMenuItem;
			if (it == null)
				return;
			if (!image.IsNull) {
				var img = new ImageBox (context, image);
				img.ShowAll ();
				it.Image = img;
				GtkWorkarounds.ForceImageOnMenuItem (it);
			}
			else
				it.Image = null;
		}

        public void Draw(ApplicationContext actx, SWM.DrawingContext dc, double scaleFactor, double x, double y, ImageDescription idesc)
        {
            if (drawCallback != null) {
                DrawingContext c = new DrawingContext (dc, scaleFactor);
                actx.InvokeUserCode (delegate {
                    drawCallback (c, new Rectangle (x, y, idesc.Size.Width, idesc.Size.Height), idesc, actx.Toolkit);
                });
            }
            else {
                if (idesc.Alpha < 1)
                    dc.PushOpacity (idesc.Alpha);

                var f = GetBestFrame (actx, scaleFactor, idesc.Size.Width, idesc.Size.Height, false);
                var bmpImage = f as BitmapSource;

                // When an image is a single bitmap that doesn't have the same intrinsic size as the drawing size, dc.DrawImage makes a very poor job of down/up scaling it.
                // Thus we handle this manually by using a TransformedBitmap to handle the conversion in a better way when it's needed.

                var scaledWidth = idesc.Size.Width * scaleFactor;
                var scaledHeight = idesc.Size.Height * scaleFactor;
                if (bmpImage != null && (Math.Abs (bmpImage.PixelHeight - scaledHeight) > 0.001 || Math.Abs (bmpImage.PixelWidth - scaledWidth) > 0.001))
                    f = new TransformedBitmap (bmpImage, new ScaleTransform (scaledWidth / bmpImage.PixelWidth, scaledHeight / bmpImage.PixelHeight));

                dc.DrawImage (f, new Rect (x, y, idesc.Size.Width, idesc.Size.Height));

                if (idesc.Alpha < 1)
                    dc.Pop ();
            }
        }

		public void SetIcon(ImageDescription icon)
		{
			Window.IconList = ((GtkImage)icon.Backend).Frames.Select (f => f.Pixbuf).ToArray ();
		}

        public override void DrawImage(object backend, ImageDescription img, double x, double y)
        {
            CairoContextBackend ctx = (CairoContextBackend)backend;

            img.Alpha *= ctx.GlobalAlpha;
            var pix = (Xwt.GtkBackend.GtkImage) img.Backend;

            pix.Draw (ApplicationContext, ctx.Context, ctx.ScaleFactor, x, y, img);
        }

 public void SetIcon(ImageDescription imageBackend)
 {
     window.Icon = imageBackend.ToImageSource ();
 }

 public override void DrawImage(object backend, ImageDescription img, double x, double y)
 {
     var srcRect = new Rectangle (Point.Zero, img.Size);
     var destRect = new Rectangle (x, y, img.Size.Width, img.Size.Height);
     DrawImage (backend, img, srcRect, destRect);
 }

		public override object Create (ImageDescription img)
		{
			return new ImagePattern (ApplicationContext, img);
		}

		public abstract object Create (ImageDescription img);

 public void SetImage(ImageDescription imageBackend)
 {
     if (imageBackend.IsNull)
         this.menuItem.Icon = null;
     else
         this.menuItem.Icon = new ImageBox (Context) { ImageSource = imageBackend };
 }

 Gdk.Pixbuf RenderFrame(ApplicationContext actx, double scaleFactor, double width, double height)
 {
     using (var sf = new Cairo.ImageSurface (Cairo.Format.ARGB32, (int)(width * scaleFactor), (int)(height * scaleFactor)))
     using (var ctx = new Cairo.Context (sf)) {
         ImageDescription idesc = new ImageDescription () {
             Alpha = 1,
             Size = new Size (width * scaleFactor, height * scaleFactor)
         };
         Draw (actx, ctx, 1, 0, 0, idesc);
         var f = new ImageFrame (ImageBuilderBackend.CreatePixbuf (sf), (int)width, (int)height);
         AddFrame (f);
         return f.Pixbuf;
     }
 }

 void DrawPixbuf(Cairo.Context ctx, Gdk.Pixbuf img, double x, double y, ImageDescription idesc)
 {
     ctx.Save ();
     ctx.Translate (x, y);
     ctx.Scale (idesc.Size.Width / (double)img.Width, idesc.Size.Height / (double)img.Height);
     Gdk.CairoHelper.SetSourcePixbuf (ctx, img, 0, 0);
     if (idesc.Alpha == 1)
         ctx.Paint ();
     else
         ctx.PaintWithAlpha (idesc.Alpha);
     ctx.Restore ();
 }

		public void SetIcon (ImageDescription icon)
		{
		}