How can I combine objects in the Raphael javascript library?

Question

Sorry for a long question but here goes. I am trying to modify the drag shapes around demo here:

http://raphaeljs.com/graffle.html

The demo works fine. What I want to do is put words inside the shapes and move the shape and text around as a composite single object.

Here is the code for creating the objects:

window.onload = function () {     var dragger = function () {         this.ox = this.type == "rect" ? this.attr("x") : this.attr("cx");         this.oy = this.type == "rect" ? this.attr("y") : this.attr("cy");         this.animate({"fill-opacity": .2}, 500);     },         move = function (dx, dy) {             var att = this.type == "rect" ? {x: this.ox + dx, y: this.oy + dy} : {cx: this.ox + dx, cy: this.oy + dy};             this.attr(att);             for (var i = connections.length; i--;) {                 r.connection(connections[i]);             }             r.safari();         },         up = function () {             this.animate({"fill-opacity": 0}, 500);         },         r = Raphael("holder", 640, 480),         connections = [],         shapes = [  r.ellipse(190, 100, 30, 20),                     r.rect(290, 80, 60, 40, 10),                     r.rect(290, 180, 60, 40, 2),                     r.ellipse(450, 100, 20, 20)                 ];     for (var i = 0, ii = shapes.length; i < ii; i++) {         var color = Raphael.getColor();         shapes[i].attr({fill: color, stroke: color, "fill-opacity": 0, "stroke-width": 2, cursor: "move"});         shapes[i].drag(move, dragger, up);     }     connections.push(r.connection(shapes[0], shapes[1], "#fff"));     connections.push(r.connection(shapes[1], shapes[2], "#fff", "#fff|5"));     connections.push(r.connection(shapes[1], shapes[3], "#000", "#fff")); }; 

I tried something like this:

 myWords = [ r.text(190, 100,  "Hello"),       r.text(480,100, "Good Bye")     ]; 

and made adjustments elsewhere so that it would work, but then it just moves text and shapes but the shape and text are never seen as a whole. I can move the text separate from the shape and vice versa. I need them to be one object. so they move together. How can I do that? Thank you for any help.

EDIT:

I tried this:

  st.push(r.text (190, 100, "node1"), r.ellipse(190, 100, 30, 20)),   st.push(r.text (290, 80, "Center"), r.rect(290, 80, 60, 40, 10)),   st.push(r.text (290, 180, "node2"), r.rect(290, 180, 60, 40, 2)),   st.push(r.text (450, 100, "node3"), r.ellipse(450, 100, 20, 20)) 

But the text and shape did not stay together when I moved the shape. The text just stayed still.

EDIT: I cannot get the stock demo at http://raphaeljs.com/graffle.html to work with Chrome. IE it works.

Answer 1

Did major edit to associate elements in a more elegant way.

---

Sets are good for grouping Raphael objects, but sets do not create their own elements, so you cannot drag and drop a set, since when you click on the canvas you either select the shape or the text, but never the set (since there is no set element).

Here is a simple jsFiddle showing the properties of a set. Note that a set has no x or y properties.

From the Raphael documentation:

[A set c]reates array-like object to keep and operate couple of elements at once. Warning: it doesn’t create any elements for itself in the page.

The simple work around is to make both the text and shape separately draggable. Then move the associated text along with the shape... and the associated shape along with the text.

Associating objects like this is simple... create a property. In this case each shape and each text has a property called .pair which is a reference to the associated element.

Here's how it's done:

var i, ii, tempS, tempT      shapes = [  ... ],      texts = [  ... ]; for (i = 0, ii = shapes.length; i < ii; i++) {     tempS = shapes[i].attr( ... );     tempT = texts[i].attr( ...);        // Make all the shapes and texts dragable     shapes[i].drag(move, dragger, up);     texts[i].drag(move, dragger, up);        // Associate the elements     tempS.pair = tempT;     tempT.pair = tempS; } 

And then in the drag and drop code, which is the move(), dragger(), and up() functions you have to make sure to deal with both the clicked on element and its associated element.

For example here is the pertinent part of the move() function. Note that text can be dealt with in the same way as rectangle (by changing attributes x and y), so the false condition in each of the Javascript conditional operators below handles both the case for rectangle and for text

move = function (dx, dy) {        // Move main element     var att = this.type == "ellipse" ?                             {cx: this.ox + dx, cy: this.oy + dy} :                             {x: this.ox + dx, y: this.oy + dy};     this.attr(att);        // Move paired element     att = this.pair.type == "ellipse" ?                              {cx: this.pair.ox + dx, cy: this.pair.oy + dy} :                              {x: this.pair.ox + dx, y: this.pair.oy + dy};     this.pair.attr(att);     ... } 

And below is the full working code:

Working jsFiddle example of draggable text and shapes

Raphael.fn.connection = function (obj1, obj2, line, bg) {     if (obj1.line && obj1.from && obj1.to) {         line = obj1;         obj1 = line.from;         obj2 = line.to;     }     var bb1 = obj1.getBBox(),         bb2 = obj2.getBBox(),         p = [{x: bb1.x + bb1.width / 2, y: bb1.y - 1},         {x: bb1.x + bb1.width / 2, y: bb1.y + bb1.height + 1},         {x: bb1.x - 1, y: bb1.y + bb1.height / 2},         {x: bb1.x + bb1.width + 1, y: bb1.y + bb1.height / 2},         {x: bb2.x + bb2.width / 2, y: bb2.y - 1},         {x: bb2.x + bb2.width / 2, y: bb2.y + bb2.height + 1},         {x: bb2.x - 1, y: bb2.y + bb2.height / 2},         {x: bb2.x + bb2.width + 1, y: bb2.y + bb2.height / 2}],         d = {}, dis = [];     for (var i = 0; i < 4; i++) {         for (var j = 4; j < 8; j++) {             var dx = Math.abs(p[i].x - p[j].x),                 dy = Math.abs(p[i].y - p[j].y);             if ((i == j - 4) || (((i != 3 && j != 6) || p[i].x < p[j].x) && ((i != 2 && j != 7) || p[i].x > p[j].x) && ((i != 0 && j != 5) || p[i].y > p[j].y) && ((i != 1 && j != 4) || p[i].y < p[j].y))) {                 dis.push(dx + dy);                 d[dis[dis.length - 1]] = [i, j];             }         }     }     if (dis.length == 0) {         var res = [0, 4];     } else {         res = d[Math.min.apply(Math, dis)];     }     var x1 = p[res[0]].x,         y1 = p[res[0]].y,         x4 = p[res[1]].x,         y4 = p[res[1]].y;     dx = Math.max(Math.abs(x1 - x4) / 2, 10);     dy = Math.max(Math.abs(y1 - y4) / 2, 10);     var x2 = [x1, x1, x1 - dx, x1 + dx][res[0]].toFixed(3),         y2 = [y1 - dy, y1 + dy, y1, y1][res[0]].toFixed(3),         x3 = [0, 0, 0, 0, x4, x4, x4 - dx, x4 + dx][res[1]].toFixed(3),         y3 = [0, 0, 0, 0, y1 + dy, y1 - dy, y4, y4][res[1]].toFixed(3);     var path = ["M", x1.toFixed(3), y1.toFixed(3), "C", x2, y2, x3, y3, x4.toFixed(3), y4.toFixed(3)].join(",");     if (line && line.line) {         line.bg && line.bg.attr({path: path});         line.line.attr({path: path});     } else {         var color = typeof line == "string" ? line : "#000";         return {             bg: bg && bg.split && this.path(path).attr({stroke: bg.split("|")[0], fill: "none", "stroke-width": bg.split("|")[1] || 3}),             line: this.path(path).attr({stroke: color, fill: "none"}),             from: obj1,             to: obj2         };     } };  var el; window.onload = function () {     var color, i, ii, tempS, tempT,         dragger = function () {                 // Original coords for main element             this.ox = this.type == "ellipse" ? this.attr("cx") : this.attr("x");             this.oy = this.type == "ellipse" ? this.attr("cy") : this.attr("y");             if (this.type != "text") this.animate({"fill-opacity": .2}, 500);                  // Original coords for pair element             this.pair.ox = this.pair.type == "ellipse" ? this.pair.attr("cx") : this.pair.attr("x");             this.pair.oy = this.pair.type == "ellipse" ? this.pair.attr("cy") : this.pair.attr("y");             if (this.pair.type != "text") this.pair.animate({"fill-opacity": .2}, 500);                     },         move = function (dx, dy) {                 // Move main element             var att = this.type == "ellipse" ? {cx: this.ox + dx, cy: this.oy + dy} :                                                 {x: this.ox + dx, y: this.oy + dy};             this.attr(att);                  // Move paired element             att = this.pair.type == "ellipse" ? {cx: this.pair.ox + dx, cy: this.pair.oy + dy} :                                                 {x: this.pair.ox + dx, y: this.pair.oy + dy};             this.pair.attr(att);                              // Move connections             for (i = connections.length; i--;) {                 r.connection(connections[i]);             }             r.safari();         },         up = function () {                 // Fade original element on mouse up             if (this.type != "text") this.animate({"fill-opacity": 0}, 500);                  // Fade paired element on mouse up             if (this.pair.type != "text") this.pair.animate({"fill-opacity": 0}, 500);                     },         r = Raphael("holder", 640, 480),         connections = [],         shapes = [  r.ellipse(190, 100, 30, 20),                     r.rect(290, 80, 60, 40, 10),                     r.rect(290, 180, 60, 40, 2),                     r.ellipse(450, 100, 20, 20)                 ],         texts = [   r.text(190, 100, "One"),                     r.text(320, 100, "Two"),                     r.text(320, 200, "Three"),                     r.text(450, 100, "Four")                 ];     for (i = 0, ii = shapes.length; i < ii; i++) {         color = Raphael.getColor();         tempS = shapes[i].attr({fill: color, stroke: color, "fill-opacity": 0, "stroke-width": 2, cursor: "move"});         tempT = texts[i].attr({fill: color, stroke: "none", "font-size": 15, cursor: "move"});         shapes[i].drag(move, dragger, up);         texts[i].drag(move, dragger, up);          // Associate the elements         tempS.pair = tempT;         tempT.pair = tempS;     }     connections.push(r.connection(shapes[0], shapes[1], "#fff"));     connections.push(r.connection(shapes[1], shapes[2], "#fff", "#fff|5"));     connections.push(r.connection(shapes[1], shapes[3], "#000", "#fff")); };​ 

---

For completeness here is the code for the linked to jsFiddle for showing the properties of a set:

window.onload = function () {     var paper = Raphael("canvas", 320, 200),         st = paper.set(),          propArr = [];      st.push(         paper.circle(10, 10, 5),         paper.circle(30, 10, 5)     );      st.attr({fill: "red"});      for(var prop in st) {         if (st.hasOwnProperty(prop)) {             // handle prop as required             propArr.push(prop + " : " + st[prop]);         }     }     alert(propArr.join("\n")); };​  // Output: // 0 : Raphael's object // 1 : Raphael's object // items : Raphael's object,Raphael's object // length : 2 // type : set