Huge Google Maps Controls (Possible Bug)

var map = null;
var chicago = new google.maps.LatLng(41.850033, -87.6500523);

/**
 * The HomeControl adds a control to the map that simply
 * returns the user to Chicago. This constructor takes
 * the control DIV as an argument.
 * @constructor
 */
function HomeControl(controlDiv, map) {

  // Set CSS styles for the DIV containing the control
  // Setting padding to 5 px will offset the control
  // from the edge of the map
  controlDiv.style.padding = '5px';

  // Set CSS for the control border
  var controlUI = document.createElement('div');
  controlUI.style.backgroundColor = 'white';
  controlUI.style.borderStyle = 'solid';
  controlUI.style.borderWidth = '2px';
  controlUI.style.cursor = 'pointer';
  controlUI.style.textAlign = 'center';
  controlUI.title = 'Click to set the map to Home';
  controlDiv.appendChild(controlUI);

  // Set CSS for the control interior
  var controlText = document.createElement('div');
  controlText.style.fontFamily = 'Arial,sans-serif';
  controlText.style.fontSize = '12px';
  controlText.style.paddingLeft = '4px';
  controlText.style.paddingRight = '4px';
  controlText.innerHTML = '<b>Home</b>';
  controlUI.appendChild(controlText);

  // Setup the click event listeners: simply set the map to
  // Chicago
  google.maps.event.addDomListener(controlUI, 'click', function() {
    map.setCenter(chicago)
  });

}

function initialize() {
  // Create the DIV to hold the control and
  // call the HomeControl() constructor passing
  // in this DIV.
  var homeControlDiv = document.createElement('div');


  var mapDiv = document.getElementById('map-canvas');
  var mapOptions = {
    zoom: 12,
    center: chicago,
    disableDefaultUI: true,
    mapTypeControl: true,
    mapTypeControlOptions: {
      style: google.maps.MapTypeControlStyle.HORIZONTAL_BAR,
      position: google.maps.ControlPosition.RIGHT_TOP
    },
    scaleControl: true,
    panControl: false,
    streetViewControl: true,
    streetViewControlOptions: {
      position: google.maps.ControlPosition.LEFT_TOP
    },
    zoomControl: true,
    zoomControlOptions: {
      position: google.maps.ControlPosition.LEFT_TOP
    }
  }

  map = new google.maps.Map(mapDiv, mapOptions);
  var PanControl = new geocodezip.web.PanControl(map);
  PanControl.index = -2;
  var homeControl = new HomeControl(homeControlDiv, map);
  homeControlDiv.index = -1;
  map.controls[google.maps.ControlPosition.LEFT_TOP].push(PanControl);
  map.controls[google.maps.ControlPosition.LEFT_TOP].push(homeControlDiv);

}

google.maps.event.addDomListener(window, 'load', initialize);

/**
 * @param {string} tagName
 * @param {Object.<string, string>} properties
 * @returns {Node}
 */
function CreateElement(tagName, properties) {
  var elem = document.createElement(tagName);
  for (var prop in properties) {
    if (prop == "style")
      elem.style.cssText = properties[prop];
    else if (prop == "class")
      elem.className = properties[prop];
    else
      elem.setAttribute(prop, properties[prop]);
  }
  return elem;
}

/**
 * @constructor
 * @param {google.maps.Map} map
 */
function PanControl(map) {
  this.map = map;
  this.originalCenter = map.getCenter();

  var t = this;
  var panContainer = CreateElement("div", {
    'style': "position: relative; padding: 5px;"
  });

  //Pan Controls
  var PanContainer = CreateElement("div", {
    'style': "position: relative; left: 2px; top: 5px; width: 56px; height: 56px; padding: 5px; overflow: hidden;"
  });
  panContainer.appendChild(PanContainer);
  var div = CreateElement("div", {
    'style': "width: 56px; height: 56px; overflow: hidden;"
  });
  div.appendChild(CreateElement("img", {
    'alt': ' ',
    'src': 'http://maps.gstatic.com/intl/en_ALL/mapfiles/mapcontrols3d5.png',
    'style': "position: absolute; left: 0px; top: -1px; -moz-user-select: none; border: 0px none; padding: 0px; margin: 0px; width: 59px; height: 492px;"
  }));
  PanContainer.appendChild(div);

  div = CreateElement("div", {
    'style': "position: absolute; left: 0px; top: 19px; width: 18.6667px; height: 18.6667px; cursor: pointer;",
    'title': 'Pan left'
  });
  google.maps.event.addDomListener(div, "click", function() {
    t.pan(PanDirection.LEFT);
  });
  PanContainer.appendChild(div);
  div = CreateElement("div", {
    'style': "position: absolute; left: 37px; top: 19px; width: 18.6667px; height: 18.6667px; cursor: pointer;",
    'title': 'Pan right'
  });
  google.maps.event.addDomListener(div, "click", function() {
    t.pan(PanDirection.RIGHT);
  });
  PanContainer.appendChild(div);
  div = CreateElement("div", {
    'style': "position: absolute; left: 19px; top: 0px; width: 18.6667px; height: 18.6667px; cursor: pointer;",
    'title': 'Pan up'
  });
  google.maps.event.addDomListener(div, "click", function() {
    t.pan(PanDirection.UP);
  });
  PanContainer.appendChild(div);
  div = CreateElement("div", {
    'style': "position: absolute; left: 19px; top: 37px; width: 18.6667px; height: 18.6667px; cursor: pointer;",
    'title': 'Pan down'
  });
  google.maps.event.addDomListener(div, "click", function() {
    t.pan(PanDirection.DOWN);
  });
  PanContainer.appendChild(div);
  div = CreateElement("div", {
    'style': "position: absolute; left: 19px; top: 19px; width: 18.6667px; height: 18.6667px; cursor: pointer;",
    'title': 'Reset center'
  });
  google.maps.event.addDomListener(div, "click", function() {
    t.map.setCenter(t.originalCenter);
  });
  PanContainer.appendChild(div);

  return panContainer;
}

/** @param {PanDirection} direction */
PanControl.prototype.pan = function(direction) {
  var panDistance = 50;
  if (direction == PanDirection.UP || direction == PanDirection.DOWN) {
    panDistance = Math.round(this.map.getDiv().offsetHeight / 2);
    this.map.panBy(0, direction == PanDirection.DOWN ? panDistance : -1 * panDistance);
  } else {
    panDistance = Math.round(this.map.getDiv().offsetWidth / 2);
    this.map.panBy(direction == PanDirection.RIGHT ? panDistance : -1 * panDistance, 0);
  }
}

/** @enum */
var PanDirection = {
  LEFT: 0,
  RIGHT: 1,
  UP: 3,
  DOWN: 4
}

window["geocodezip"] = window["geocodezip"] || {};
window["geocodezip"]["web"] = window["geocodezip"]["web"] || {};
window["geocodezip"]["web"]["PanControl"] = PanControl;

html,
body,
#map-canvas {
  height: 100%;
  margin: 0px;
  padding: 0px
}

<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCkUOdZ5y7hMm0yrcCQoCvLwzdM6M8s5qk"></script>

<div id="map-canvas"></div>

Google Maps API - Customising the Appearance of certain controls

It turns it was an issue with the latest 3.34 release of the Google Maps JavaScript API. I've managed to revert to the previous version for now, e.g. http://maps.google.com/maps/api/js?v=3.33&key=xxxxxxx

Google Maps v3 performance issues

The reason for that is that google maps api it's not the same javascript as google maps application is using.

If you take a look at the resulting map you can see that your map created with the api, is created by multiple divs, each div is one map tile image.
During zooming every single tile has to be re-rendered with a new image.
Also in the network tab you can see that you are downloading map tiles as images.

On the other hand, google maps application has one canvas element, and during zooming you are not downloading images but vector data (in some google format kind) and they are rendered into the canvas. Canvas object is natively supported and is less expensive than replacing images using DOM elements.

---

Related Topics