gistfile1.js

var behaviours = {
	select: {
		onstart: function(p) {
			var viewer = this.workspace.viewer;
			this.from = {
				x: p.x - (p.x % viewer.gridSize),
				y: p.y - (p.y % viewer.gridSize)
			};
			viewer.unselect();
		},
		onresume: function(p) {
			var from = this.from;
			if (from) {
				var viewer = this.workspace.viewer;
				var compo = viewer.compo;
				this.mousemoved = true;
				var to = {
					x: p.x - (p.x % viewer.gridSize),
					y: p.y - (p.y % viewer.gridSize)
				};
				if (from.x <= to.x) {
					to.x += viewer.gridSize;
				}
				if (to.x < 0) {
					to.x = 0;
				} else if (compo.width < to.x) {
					to.x = compo.width - compo.width % viewer.gridSize;
				}
				if (from.y <= to.y) {
					to.y += viewer.gridSize;
				}
				if (to.y < 0) {
					to.y = 0;
				} else if (compo.height < to.y) {
					to.y = compo.height - compo.height % viewer.gridSize;
				}
				viewer.select(from.x, from.y, to.x, to.y);
			}
		},
		onfinish: function(p) {
			var from = this.from;
			if (from) {
				var viewer = this.workspace.viewer;
				if (this.mousemoved) {
					var compo = viewer.compo;
					var to = {
						x: p.x - (p.x % viewer.gridSize),
						y: p.y - (p.y % viewer.gridSize)
					};
					if (from.x <= to.x) {
						to.x += viewer.gridSize;
					}
					if (to.x < 0) {
						to.x = 0;
					} else if (compo.width < to.x) {
						to.x = compo.width - compo.width % viewer.gridSize;
					}
					if (from.y <= to.y) {
						to.y += viewer.gridSize;
					}
					if (to.y < 0) {
						to.y = 0;
					} else if (compo.height < to.y) {
						to.y = compo.height - compo.height % viewer.gridSize;
					}
					viewer.select(from.x, from.y, to.x, to.y);
				} else {
					viewer.unselect();
				}
				delete this.mousemoved;
				delete this.from;
			}
		}
	}
};