Implement DocumentView.

src/document/DocumentView.js

@@ -0,0 +1,97 @@
+DocumentView = Base.extend({
+	beans: true,
+
+	initialize: function(document) {
+		this.document = document;
+		this._bounds = this.document.bounds.clone();
+		this.matrix = new Matrix();
+		this._zoom = 1;
+		this._center = this._bounds.center;
+	},
+	
+	// TODO: test this.
+	getCenter: function() {
+		return this._center;
+	},
+	
+	setCenter: function() {
+		var center = Point.read(arguments);
+		if (center) {
+			var delta = center.subtract(this._center);
+			this.scrollBy(delta);
+			this._center = center;
+		}
+	},
+	
+	getZoom: function() {
+		return this._zoom;
+	},
+	
+	setZoom: function(zoom) {
+		// TODO: clamp the view between 1/32 and 64?
+		var mx = new Matrix();
+		mx.scale(zoom / this._zoom, this.center);
+		this.transform(mx);
+		this._zoom = zoom;
+	},
+	
+	scrollBy: function() {
+		var point = Point.read(arguments).negate();
+		var mx = new Matrix().translate(point);
+		this.transform(mx);
+	},
+	
+	getBounds: function() {
+		return this._bounds;
+	},
+	
+	// TODO:
+	// setBounds: function(rect) {
+	// 
+	// },
+	
+	// TODO: getInvalidBounds
+	// TODO: invalidate(rect)
+	// TODO: style: artwork / preview / raster / opaque / ink
+	// TODO: getShowGrid
+	// TODO: getMousePoint
+	// TODO: artworkToView(rect)
+	artworkToView: function(point) {
+		return this.matrix.transform(point);
+	},
+	
+	viewToArtwork: function(point) {
+		// TODO: cache the inverse matrix:
+		return this.matrix.createInverse().transform(point);
+	},
+	
+	// TODO: inherit this code somehow?
+	transform: function(matrix, flags) {
+		var width = this.document.bounds.width;
+		var height = this.document.bounds.height;
+		var x = width * -0.5;
+		var y = height * -0.5;
+		var coords = [
+			x, y,
+			x + width, y,
+			x + width, y + height,
+			x, y + height];
+		this.matrix.preConcatenate(matrix);
+		this.matrix.createInverse().transform(coords, 0, coords, 0, 4);
+		var xMin = coords[0], xMax = coords[0];
+		var yMin = coords[1], yMax = coords[1];
+		for (var i = 2; i < 8; i += 2) {
+			var x = coords[i];
+			var y = coords[i + 1];
+			xMin = Math.min(x, xMin);
+			xMax = Math.max(x, xMax);
+			yMin = Math.min(y, yMin);
+			yMax = Math.max(y, yMax);
+		};
+		var bounds = this._bounds;
+		bounds.x = xMin;
+		bounds.y = yMin;
+		bounds.width = xMax - xMin;
+		bounds.height = yMax - yMin;
+	}
+});