Simple SVG Editor

goodwangLib 2012-01-09

展开全文

SvgPaint is the simplest SVG editor. This application is a combination of two projects from The Code Project: DrawTools by Alex Fry and SVGPad by Maurizio Bigoloni. This application implements only trivial graphics elements from SVG format, no rendering, no transforming, etc.

How It Works

SvgLib reads and parses the Svg file and creates object SvgDoc with SvgElements.

Then, from SvgElements, create the DrawObjects, objects by DrawObject library.

After editing using the DrawTools library, the graphics objects may be saved in the edited Svg file.

I do not use serialization because it is used in the DrawTools project. I added to DrawObjects static methods that create an XML string with graphic elements in Svg format.

I also added a few graphics classes into used projects:

SvgPolyline into SvgPad
DrawText, DrawImage into DrawTools

Moreover, I added scaling capability and filling.

How to Transform Svg Elements to Draw Objects

After created SvgDoc, calling recursing method AddFromSvg() (beginning from root element), that, for all Svg elements, calls static method CreateDrawObject() of the DrawObject class:

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public void AddFromSvg(SvgElement ele) 
{ 
	while (ele != null) 
	{ 
		DrawObject o = this.CreateDrawObject(ele); 
		if (o != null) 
			Add(o); 
		SvgElement child = ele.getChild(); 
		while (child != null) 
		{ 
			AddFromSvg(child); 
			child = child.getNext(); 
		} 
		ele = ele.getNext(); 
	} 
}

The method CreateDrawObject() of basic class DrawObject has input parameter SvgElement and calls static method Create() of inherited draw objects that create themselves.

Then, the new draw objects add to GraphicsList object:

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DrawObject CreateDrawObject(SvgElement svge) 
{ 
	DrawObject o = null; 
	switch (svge.getElementType()) 
	{ 
		case SvgElement._SvgElementType.typeLine: 
			o = DrawLine.Create((SvgLine )svge); 
			break; 
		case SvgElement._SvgElementType.typeRect: 
			o = DrawRectangle.Create((SvgRect )svge); 
			break; 
		case SvgElement._SvgElementType.typeEllipse: 
			o = DrawEllipse.Create((SvgEllipse )svge); 
			break; 
		case SvgElement._SvgElementType.typePolyline: 
			o = DrawPolygon.Create((SvgPolyline )svge); 
			break; 
		case SvgElement._SvgElementType.typeImage: 
			o = DrawImage.Create((SvgImage )svge); 
			break; 
		case SvgElement._SvgElementType.typeText: 
			o = DrawText.Create((SvgText )svge); 
			break; 
		case SvgElement._SvgElementType.typeGroup: 
			o = CreateGroup((SvgGroup )svge); 
			break; 
		default: 
		break; 
	} 
	return o; 
}