paper.js/src/item/Item.js

Item = Base.extend({
	beans: true,

	initialize: function() {
		this.parent = Paper.document.activeLayer;
		this.parent.children.push(this);
	},
	
	/**
	 * When passed a document, copies the item to the document,
	 * or duplicates it within the same document. When passed an item,
	 * copies the item into the specified item.
	 * 
	 * @param document the document to copy the item to
	 * @return the new copy of the item
	 */
	
	copyTo: function(itemOrDocument) {
		var copy = Base.clone(this);
		if (itemOrDocument.layers) {
			copy.parent = itemOrDocument.activeLayer;
			itemOrDocument.activeLayer.appendTop(copy);
		} else {
			copy.parent = itemOrDocument;
			itemOrDocument.appendTop(copy);
		}
		return copy;
	},
	
	/**
	 * Clones the item within the same document.
	 * 
	 * @return the newly cloned item
	 */
	
	clone: function() {
		return this.copyTo(this.parent);
	},
	
	/**
	 * Specifies whether the item is locked.
	 * 
	 * Sample code:
	 * <code>
	 * var path = new Path();
	 * print(path.locked) // false
	 * path.locked = true; // Locks the path
	 * </code>
	 * 
	 * @return {@true if the item is locked}
	 */
	
	locked: false,
	
	/**
	 * Specifies whether the item is visible.
	 * 
	 * Sample code:
	 * <code>
	 * var path = new Path();
	 * print(path.visible) // true
	 * path.visible = false; // Hides the path
	 * </code>
	 * 
	 * @return {@true if the item is visible}
	 */
	
	visible: true,
	
	/**
	 * The opacity of the item.
	 * 
	 * Sample code:
	 * <code>
	 * // Create a circle at position { x: 10, y: 10 } 
	 * var circle = new Path.Circle(new Point(10, 10), 10);
	 * 
	 * // Change the opacity of the circle to 50%:
	 * circle.opacity = 0.5;
	 * </code>
	 * 
	 * @return the opacity of the item as a value between 0 and 1.
	 */
	
	opacity: 1,
	
	/**
	 * Specifies whether the item is hidden.
	 * 
	 * Sample code:
	 * <code>
	 * var path = new Path();
	 * print(path.hidden); // false
	 * path.hidden = true; // Hides the path
	 * </code>
	 * 
	 * @return {@true if the item is hidden}
	 * 
	 * @jshide
	 */
	
	isHidden: function() {
		return !this.visible;
	},
	
	setHidden: function(hidden) {
		this.setVisible(!hidden);
	},
	
	/**
	 * Specifies whether the item defines a clip mask. This can only be set on
	 * paths, compound paths, and text frame objects, and only if the item is
	 * already contained within a clipping group.
	 * 
	 * Sample code:
	 * <code>
	 * var group = new Group();
	 * group.appendChild(path);
	 * group.clipped = true;
	 * path.clipMask = true;
	 * </code>
	 * 
	 * @return {@true if the item defines a clip mask}
	 */
	isClipMask: function() {
		return this.clipMask;
	},
	
	setClipMask: function(clipMask) {
		this.clipMask = clipMask;
		if (this.clipMask) {
			this.fillColor = null;
			this.strokeColor = null;
		}
	},
	
	/**
	 * The first item contained within this item.
	 */
	getFirstChild: function() {
		if (this.children.length > 0)
			return this.children[0];
	},

	/**
	 * The last item contained within this item.
	 */
	getLastChild: function() {
		if (this.children.length > 0)
			return this.children[this.children.length - 1];
	},
	
	/**
	 * The next item on the same level as this item.
	 */
	getNextSibling: function() {
		if (this.parent) {
			var index = this.index + 1;
			if (index < this.parent.children.length)
				return this.parent.children[index];
		}
	},

	/**
	 * The previous item on the same level as this item.
	 */
	getPreviousSibling: function() {
		if (this.parent) {
			var index = this.index - 1;
			if (index <= 0)	
				return this.parent.children[index];
		}
	},

	/**
	 * The index of this item within the list of it's parent's children.
	 */
	getIndex: function() {
		// TODO: Relying on indexOf() here is slow, especially since it is
		// used for getPrevious/NextSibling(). 
		// We need linked lists instead.
		return this.parent.children.indexOf(this);
	},
	
	/**
	* Removes the item from its parent's children list.
	*/
	removeFromParent: function() {
		if (this.parent)
			this.parent.children.splice(this.index, 1);
		this.parent = null;
	},
	
	/**
	* Removes the item.
	*/	
	remove: function() {
		this.removeFromParent();
	},
	
	/**
	 * {@grouptitle Tests}
	 * 
	 * Checks if the item contains any children items.
	 * 
	 * @return {@true if it has one or more children}
	 */
	hasChildren: function() {
		return this.children && this.children.length;
	},
	
	/**
	 * Checks whether the item is editable.
	 * 
	 * @return {@true when neither the item, nor it's parents are locked or
	 * hidden}
	 */
	isEditable: function() {
		var parent = this;
		while(parent) {
			if (parent.hidden || parent.locked)
				return false;
			parent = parent.parent;
		}
		return true;
	},
	
	/**
	 * {@grouptitle Hierarchy Operations}
	 * 
	 * Inserts the specified item as a child of the item by appending it to the
	 * list of children and moving it above all other children. You can use this
	 * function for groups, compound paths and layers.
	 * 
	 * Sample code:
	 * <code>
	 * var group = new Group();
	 * var path = new Path();
	 * group.appendTop(path);
	 * print(path.isDescendant(group)); // true
	 * </code>
	 * 
	 * @param item The item that will be appended as a child
	 */
	appendTop: function(item) {
		item.removeFromParent();
		this.children.push(item);
		item.parent = this;
		item.document = this.document;
	},
	
	/**
	 * Inserts the specified item as a child of this item by appending it to the
	 * list of children and moving it below all other children. You can use this
	 * function for groups, compound paths and layers.
	 * 
	 * Sample code:
	 * <code>
	 * var group = new Group();
	 * var path = new Path();
	 * group.appendBottom(path);
	 * print(path.isDescendant(group)); // true
	 * </code>
	 * 
	 * @param item The item that will be appended as a child
	 */
	appendBottom: function(item) {
		item.removeFromParent();
		this.children.splice(0, 0, item);
		item.parent = this;
		item.document = this.document;
	},
	
	/**
	 * A link to {@link #appendTop}
	 * 
	 * @deprecated use {@link #appendTop} or {@link #appendBottom} instead.
	 */
	appendChild: function(item) {
		return this.appendTop(item);
	},
	
	/**
	 * Moves this item above the specified item.
	 * 
	 * Sample code:
	 * <code>
	 * var firstPath = new Path();
	 * var secondPath = new Path();
	 * print(firstPath.isAbove(secondPath)); // false
	 * firstPath.moveAbove(secondPath);
	 * print(firstPath.isAbove(secondPath)); // true
	 * </code>
	 * 
	 * @param item The item above which it should be moved
	 * @return true if it was moved, false otherwise
	 */
	moveAbove: function(item) {
		// first remove the item from its parent's children list
		this.removeFromParent();
		item.parent.children.splice(item.index + 1, 0, this);
		this.parent = item.parent;
		this.document = item.document;
		return true;
	},
	
	/**
	 * Moves the item below the specified item.
	 * 
	 * Sample code:
	 * <code>
	 * var firstPath = new Path();
	 * var secondPath = new Path();
	 * print(secondPath.isBelow(firstPath)); // false
	 * secondPath.moveBelow(firstPath);
	 * print(secondPath.isBelow(firstPath)); // true
	 * </code>
	 * 
	 * @param item the item below which it should be moved
	 * @return true if it was moved, false otherwise
	 */
	moveBelow: function(item) {
		// first remove the item from its parent's children list
		this.removeFromParent();
		item.parent.children.splice(item.index - 1, 0, this);
		this.parent = item.parent;
		this.document = item.document;
		return true;
	},
	
	// TODO: this is confusing the beans
	// isParent: function(item) {
	// 	return this.parent == item;
	// },
	
	isChild: function(item) {
		return item.parent == this;
	},
	
	/**
	 * Checks if the item is contained within the specified item.
	 * 
	 * Sample code:
	 * <code>
	 * var group = new Group();
	 * var path = new Path();
	 * group.appendTop(path);
	 * print(path.isDescendant(group)); // true
	 * </code>
	 * 
	 * @param item The item to check against
	 * @return {@true if it is inside the specified item}
	 */
	isDescendant: function(item) {
		var parent = this;
		while(parent) {
			if (parent == item)
				return true;
			parent = parent.parent;
		}
		return false;
	},
	
	/**
	 * Checks if the item is an ancestor of the specified item.
	 * 
	 * Sample code:
	 * <code>
	 * var group = new Group();
	 * var path = new Path();
	 * group.appendChild(path);
	 * print(group.isAncestor(path)); // true
	 * print(path.isAncestor(group)); // false
	 * </code>
	 * 
	 * @param item the item to check against
	 * @return {@true if the item is an ancestor of the specified item}
	 */
	isAncestor: function(item) {
		var parent = item;
		while(parent) {
			if (parent == this)
				return true;
			parent = parent.parent;
		}
		return false;
	},

	getBounds: function() {
		// TODO: Implement
		return new Rectangle();
	},

	setBounds: function(rect) {
		var bounds = this.bounds;
		rect = Rectangle.read(arguments);
		var matrix = new Matrix();
		// Read this from bottom to top:
		// Translate to new center:
		var center = rect.center;
		matrix.translate(center);
		// Scale to new Size, if size changes and avoid divisions by 0:
		if (rect.width != bounds.width || rect.height != bounds.height) {
			matrix.scale(
					bounds.width != 0 ? rect.width / bounds.width : 1,
					bounds.height != 0 ? rect.height / bounds.height : 1);
		}
		// Translate to center:
		center = bounds.center;
		matrix.translate(-center.x, -center.y);
		// Now execute the transformation:
		transform(matrix);
	},

	/**
	 * The item's position within the art board. This is the
	 * {@link Rectangle#getCenter()} of the {@link Item#getBounds()} rectangle.
	 * 
	 * Sample code:
	 * <code>
	 * // Create a circle at position { x: 10, y: 10 }
	 * var circle = new Path.Circle(new Point(10, 10), 10);
	 * 
	 * // Move the circle to { x: 20, y: 20 }
	 * circle.position = new Point(20, 20);
	 * 
	 * // Move the circle 10 points to the right
	 * circle.position += new Point(10, 0);
	 * print(circle.position); // { x: 30, y: 20 }
	 * </code>
	 */
	getPosition: function() {
		return this.bounds.center;
	},

	setPosition: function(point) {
		translate(point.subtract(this.position));
	},

	/**
	 * @param flags: Array of any of the following: 'objects', 'children',
	 *     'fill-gradients', 'fill-patterns', 'stroke-patterns', 'lines'. 
	 *     Default: ['objects', 'children']
	 */
	transform: function(matrix, flags) {
		// TODO: Walk DOM and call transform on chidren, depending on flags
		// TODO: Handle flags, add TransformFlag class and convert to bit mask
		// for quicker checking
		if (this.transformContent)
			this.transformContent(matrix, flags);
		if (this.children) {
			for (var i = 0, l = this.children.length; i < l; i++) {
				var child = this.children[i];
				child.transform(matrix, flags);
			}
		}
	},

/*
	transformContent: function(matrix, flags) {
		// The code that performs the actual transformation of content,
		// if defined. Item itself does not define this.
	},
*/
	/**
	 * Translates (moves) the item by the given offset point.
	 * 
	 * Sample code:
	 * <code>
	 * // Create a circle at position { x: 10, y: 10 } 
	 * var circle = new Path.Circle(new Point(10, 10), 10);
	 * circle.translate(new Point(5, 10));
	 * print(circle.position); // {x: 15, y: 20}
	 * </code>
	 * 
	 * Alternatively you can also add to the {@link #getPosition()} of the item:
	 * <code>
	 * // Create a circle at position { x: 10, y: 10 } 
	 * var circle = new Path.Circle(new Point(10, 10), 10);
	 * circle.position += new Point(5, 10);
	 * print(circle.position); // {x: 15, y: 20}
	 * </code>
	 * 
	 * @param delta
	 */
	translate: function(delta) {
		var mx = new Matrix();
		mx.translate.apply(mx, arguments);
		this.transform(mx);
	},

	/**
	 * {@grouptitle Transform Functions}
	 * 
	 * Scales the item by the given values from its center point, or optionally
	 * by a supplied point.
	 * 
	 * @param sx
	 * @param sy
	 * @param center {@default the center point of the item}
	 * 
	 * @see Matrix#scale(double, double, Point center)
	 */
	scale: function(sx, sy /* | scale */, center) {
		// TODO: Make single scale parameter work, and still pass center
		// or position
		this.transform(new Matrix().scale(sx, sy, center || this.position));
	},

	/**
	 * Rotates the item by a given angle around the given point.
	 * 
	 * Angles are oriented clockwise and measured in degrees by default. Read
	 * more about angle units and orientation in the description of the
	 * {@link com.scriptographer.ai.Point#getAngle()} property.
	 * 
	 * @param angle the rotation angle
	 * @see Matrix#rotate(double, Point)
	 */
	rotate: function(angle, center) {
		this.transform(new Matrix().rotate(angle, center || this.position));
	},

	/**
	 * Shears the item with a given amount around its center point.
	 * 
	 * @param shx
	 * @param shy
	 * @see Matrix#shear(double, double)
	 */
	shear: function(shx, shy, center) {
		// TODO: Add support for center ack to Scriptographer too!
		this.transform(new Matrix().shear(shx, shy, center || this.position));
	}
});