paint_client_backup.js

window.onload = load;

var canvas_size = 200;
var cell_size = 3; // Each cell is 3x3 pixels.

var pen_color = "black";
var pen_size = 8; // This must always be a multiple of 4.
var brushSizeSelectors;

var changedCells = [];
var clickedCells = [];
var lastCell = [];

var canvas_mouse_x = 0;
var canvas_mouse_y = 0;
var canvas_left_x = 0;
var canvas_top_y = 0;

var table, canvasOverlay;
var clickDownFlag = false;
var clickDragFlag = false;

var tableArray = [];

function load()
{
  console.log("Loaded");
  setupTable();
  setupCanvasOverlay();
  addMouseListener();
  setupColorSelectors();
  window.setInterval(pollColors, 200);
  window.setTimeout(
    function() { window.setInterval(sendColors, 100); },
    100
  );
}

function setupTable()
{
  table = document.getElementById("tbody");
  for(var i = 0; i < canvas_size; i++)
  {
    var rowArray = [];
    var row = document.createElement("tr");
    for (var j = 0; j < canvas_size; j++)
    {
      var cell = document.createElement("td");
      cell.x = i;
      cell.y = j;
      cell.lastUpdated = new Date().getTime();
      cell.style.backgroundColor = "#ffffff";
      // cell.addEventListener("mousedown", changeCell(i, j, this.style.backgroundColor));
      row.appendChild(cell);
      rowArray.push(cell);
    }
    table.appendChild(row);
    tableArray.push(rowArray);
  }
}

function setupCanvasOverlay()
{
  canvasOverlay = document.getElementById("canvas_overlay");
  canvas_left_x = canvasOverlay.getBoundingClientRect().left;
  canvas_top_y = canvasOverlay.getBoundingClientRect().top;

  /* This mouse drag detection code adapted from:
   * http://stackoverflow.com/a/6042235/3673087 */

  canvasOverlay.addEventListener("mousedown", function() {
      clickDownFlag = true;
      clickDragFlag = false;
      clickCell();
  }, true);
  canvasOverlay.addEventListener("mousemove", function() {
      clickDragFlag = true;
      if(clickDownFlag) {
        clickCell();
      }
  }, true);
  document.addEventListener("mouseup", function() {
      if(!clickDragFlag || !clickDownFlag) {
          console.log("click");
      }
      else if(clickDragFlag && clickDownFlag) {
          clickCell();
          console.log("drag");
      }
      changeClickedCells();
      clickDownFlag = false;
  }, true);
}

function addMouseListener()
{
  document.addEventListener("mousemove", function(e) {
    var mouse_x = e.pageX || e.clientX;
    var mouse_y = e.pageY || e.clientY;
    canvas_mouse_x = Math.max(Math.floor(mouse_x - canvas_left_x), 0);
    canvas_mouse_y = Math.max(Math.floor(mouse_y - canvas_top_y), 0);
  }, false);
}

function setupColorSelectors()
{
  var colorSelectors = document.getElementsByClassName("selector");
  for(var i=0; i<colorSelectors.length; i++) {
    if(i !== colorSelectors.length - 1) {
      colorSelectors.item(i).onclick = changePenColor;
    } else {
      colorSelectors.item(i).onclick = openColorInput;
      colorSelectors.item(i).getElementsByTagName("input").item(0).oninput = changePenColorInput;
    }
  }
  var clearButton = document.getElementById("clear");
  clearButton.onclick = clearCanvas;
  brushSizeSelectors = document.getElementsByClassName("brush");
  for(i=0; i<brushSizeSelectors.length; i++) {
    brushSizeSelectors.item(i).onclick = changePenSize;
  }
}

function changePenColor()
{
  pen_color = this.style.backgroundColor;
  console.log("Changed pen color to " + pen_color);
}

function openColorInput()
{
  console.log("Detected color input click.");
  this.getElementsByTagName("input").item(0).click();
}

function changePenColorInput(e)
{
  pen_color = this.value;
  this.parentNode.style.backgroundColor = pen_color;
  console.log("Changed pen color to " + pen_color);
}

function changePenSize()
{
  pen_size = parseInt(this.getAttribute("data-size"));
  for(var i=0; i<brushSizeSelectors.length; i++) {
    var brush = brushSizeSelectors.item(i);
    if(brush === this) {
      brush.className = "brush selected";
    } else {
      brush.className = "brush";
    }
  }
}

function clearCanvas()
{
  var send_change = new XMLHttpRequest();
  send_change.open("get", "clear_canvas");
  send_change.send();
}

function clickCell()
{
  var x = Math.round(canvas_mouse_x/cell_size);
  var y = Math.round(canvas_mouse_y/cell_size);
  var c = pen_color;
  var cellIndex = x + (pen_size/4 - i);
  var rowIndex = y + (pen_size/4 - j);
  for(var i=0; i<pen_size/2; i++) {
    for(var j=0; j<pen_size/2; j++) {
      try {
        var tableCell = tableArray[rowIndex][cellIndex];
        //console.log(tableCell);
        tableCell.style.backgroundColor = c;
        tableCell.lastUpdated = new Date().getTime();
        if(clickedCells.indexOf(tableCell) === -1)
        {
          clickedCells.push(tableCell); //,pen color?
        }

      } catch(e) {
        console.log("Error: Couldn't paint cell ["+rowIndex+", "+cellIndex+"]:"+e);
      }
    }
  }
  smooth([rowIndex,cellIndex]);
  lastCell = [rowIndex,cellIndex];
}

function changeClickedCells()
{
  // console.log("MOUSEUP. Clicked "+clickedCells.length+" cells.");
  for(var i=0; i<clickedCells.length; i++) {
    changedCells.push(clickedCells[i]);
  }
  clickedCells = [];
}

function sendColors()
{
  // console.log("Sending colors.");
  if(changedCells.length > 0) {
    var url = "change_cells?";
    var i;
    for(i=0; i<changedCells.length; i++) {
      var cell = changedCells[i];
      //console.log(cell);
      //newColorHash = cell.style.backgroundColor;
      //newColor = newColorHash.replace("#","");
      //console.log(cell.x);
      var newData = "c"+i+"="+cell.x+"-"+cell.y+"-"+pen_color+"&";
      url += newData;
    }
    // console.log("SENDING. Url has "+i+" cells.");
    changedCells = [];
    var send_change = new XMLHttpRequest();
    send_change.open("get", url);
    send_change.send();
  }
}

function pollColors()
{
  // console.log("Polling colors.");
  var request_colors = new XMLHttpRequest();
  request_colors.startTime = new Date().getTime();
  request_colors.onload = colorsListener;
  request_colors.open( "get", "get_changed_cells" );
  request_colors.send();
}

function colorsListener()
{
  this.endTime = new Date().getTime();
  // console.log("Request load time: "+(this.endTime-this.startTime)+". Parsing response...");
  var canvas = JSON.parse(this.responseText);
  var cellCount = 0;
  var changedCellCount = 0;
  if(canvas instanceof Array) {
    for(var i=0; i<canvas.length; i++) {
      var canvasRow = canvas[i];
      var tableRow = tableArray[i];
      if(tableRow && canvasRow instanceof Array) {
        for(var j=0; j<canvasRow.length; j++) {
          var cellColor = canvasRow[j];
          var tableCell = tableRow[j];
          if(tableCell) {
            cellCount++;
            var currentColor = tableCell.style.backgroundColor;
            if(!colorsSame(currentColor, cellColor) &&
                this.startTime - tableCell.lastUpdated > 0 &&
                changedCells.indexOf(tableCell) === -1 &&
                clickedCells.indexOf(tableCell) === -1) {

              changedCellCount++;
              tableCell.style.backgroundColor = cellColor;

            } else {
              // console.log("Warning: Cell ["+i+", "+j+"] has been updated on the client more recently than the server. Won't overwrite.");
            }
          } else {
            console.log("Error: Response did not match table cell.");
          }
        }
      } else {
        console.log("Error: Response was not a multidimensional array.");
      }
    }
  } else {
    console.log("Error: Response was not an array.");
  }
  // console.log("DONE PARSING. Response changed "+changedCellCount+" cells ("+cellCount+" total).");
}

function colorsSame(color1, color2) {
  var same = false;
  if(color1 === color2) {
    same = true;
  } else {
    if(color1.toString().indexOf("#") > -1 && color2.toString().indexOf("rgb") > -1) {
      color1 = hexToRgb(color1);
    } else if(color2.toString().indexOf("#") > -1 && color1.toString().indexOf("rgb") > -1) {
      color2 = hexToRgb(color2);
    }
    if(color1 === color2) {
      same = true;
    }
  }
  return same;
}

/* This function from http://stackoverflow.com/a/5624139/3673087 */
function hexToRgb(hex) {
    var result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
    return result ?
        "rgb(" + parseInt(result[1], 16) + ", " +
        parseInt(result[2], 16) + ", " +
        parseInt(result[3], 16) + ")"
    : null;
}

function smooth(newCell)
{
  //console.log("new:"+newCell+"old:"+lastCell);
  var pen_radius = pen_size/2;
  var right, down;
  if (Math.abs(newCell[0]-lastCell[0]) <= pen_size && Math.abs(newCell[1]-lastCell[1]) <= pen_size)
  {
    return;
  }
  /*if (lastCell = [])
  {
    lastCell = newCell;
    return;
  }*/
  else
  {
    //console.log(lastCell)
    if (clickDragFlag)
    {
      var slope = (newCell[0]-lastCell[0])/(newCell[1]-lastCell[1]);
      if(!isFinite(slope) || slope  > 15 || slope < -15)
      {
        for (i = 1; i < Math.abs(newCell[0]-lastCell[0]); i++)
        {
          if(newCell[0]-lastCell[0] > 0)
          {
            var new1 = lastCell[1];
            var new0 = lastCell[0] + i;
          }
          else if (newCell[0]-lastCell[0] < 0)
          {
            var new1 = lastCell[1];
            var new0 = lastCell[0] - i;
          }
        }
      }
      if(isFinite(slope) && !isNaN(slope))
      {
        console.log("x: "+(newCell[0]-lastCell[0])+" y: "+(newCell[1]-lastCell[1]));
        for (i = 1; i < Math.abs(newCell[1]-lastCell[1]); i++)
        {
          if ((newCell[0]-lastCell[0])>0 && (newCell[1]-lastCell[1])>0)
          {
            var new0 = Math.floor(lastCell[0]+(slope*i));
            var new1 = Math.floor(lastCell[1]+i);
          }
          //console.log(i+"[0]:"+new0);
          else if ((newCell[0]-lastCell[0])<0 && (newCell[1]-lastCell[1])>0)
          {
            var new0 = Math.floor(lastCell[0]+(slope*i));
            var new1 = Math.floor(lastCell[1]+i);
          }
          else if((newCell[0]-lastCell[0])<0 && (newCell[1]-lastCell[1])<0)
          {
            var new0 = Math.floor(lastCell[0]+(slope*(-i)));
            var new1 = Math.floor(lastCell[1]-i);
          }
          else if((newCell[0]-lastCell[0])>0 && (newCell[1]-lastCell[1])<0)
          {
            var new0 = Math.floor(lastCell[0]+(slope*(-i)));
            var new1 = Math.floor(lastCell[1]-i);
          }
          //console.log("[1]:"+new1);
          /*try{
            var tableCell = tableArray[new0][new1];
            tableCell.style.backgroundColor = pen_color;
            tableCell.lastUpdated = new Date().getTime();
            console.log(tableCell);
            clickedCells.push(tableCell, pen_color);
          }
          catch(e)
          {
            console.log("Couldn't paint cell")
          }*/

          /*for(var i=0; i<pen_radius; i++) {
            for(var j=0; j<pen_radius; j++) {
              var cellIndex = new1 + (pen_size/4 - i);
              var rowIndex = new0 + (pen_size/4 - j);
              try {
                var tableCell = tableArray[rowIndex][cellIndex];
                tableCell.style.backgroundColor = pen_color;
                tableCell.lastUpdated = new Date().getTime();
                clickedCells.push(tableCell);

              } catch(e) {
                console.log("Error: Couldn't paint cell ["+rowIndex+", "+cellIndex+"].");
              }
            }
          }*/
          console.log("0:"+new0+" 1:"+new1);
          var url = "build_array?zero="+new0+"&one="+new1+"&color="+pen_color+"&size="+pen_radius;
          var build_array = new XMLHttpRequest;
          build_array.onload = colorsListener;
          build_array.open("get", url);
          build_array.send();
        }
      }
    }
  }
}