path: root/src/svgpan.js

/**
 * The code below is based on SVGPan Library 1.2 and was modified for doxygen
 * to support both zooming and panning via the mouse and via embedded bottons.
 *
 * This code is licensed under the following BSD license:
 *
 * Copyright 2009-2010 Andrea Leofreddi <a.leofreddi@itcharm.com>. All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 * 
 *    1. Redistributions of source code must retain the above copyright notice, this list of
 *       conditions and the following disclaimer.
 * 
 *    2. Redistributions in binary form must reproduce the above copyright notice, this list
 *       of conditions and the following disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY Andrea Leofreddi ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL Andrea Leofreddi OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * The views and conclusions contained in the software and documentation are those of the
 * authors and should not be interpreted as representing official policies, either expressed
 * or implied, of Andrea Leofreddi.
 */

var root = document.documentElement;
var state = 'none';
var stateOrigin;
var stateTf = root.createSVGMatrix();
var cursorGrab = ' url("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAA4AAAAOCAMAAAAolt3jAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAAAlQTFRFAAAA////////c3ilYwAAAAN0Uk5T//8A18oNQQAAAD1JREFUeNp0zlEKACAIA9Bt9z90bZBZkQj29qFBEuBOzQHSnWTTyckEfqUuZgFvslH4ch3qLCO/Kr8cAgwATw4Ax6XRCcoAAAAASUVORK5CYII="), move';
var zoomSteps = 10;
var zoomInFactor;
var zoomOutFactor;
var windowWidth;
var windowHeight;
var svgDoc;
var minZoom;
var maxZoom;
if (!window) window=this;

/**
 * Show the graph in the middle of the view, scaled to fit 
 */
function show()
{
  if (window.innerHeight) // Firefox
  {
    windowWidth = window.innerWidth;
    windowHeight = window.innerHeight;
  }
  else if (document.documentElement.clientWidth) // Chrome/Safari
  {
    windowWidth = document.documentElement.clientWidth
    windowHeight = document.documentElement.clientHeight
  }
  if (!windowWidth || !windowHeight) // failsafe
  {
    windowWidth = 800;
    windowHeight = 600;
  }
  minZoom = Math.min(Math.min(viewHeight,windowHeight)/viewHeight,Math.min(viewWidth,windowWidth)/viewWidth);
  maxZoom = minZoom+1.5;
  zoomInFactor = Math.pow(maxZoom/minZoom,1.0/zoomSteps);
  zoomOutFactor = 1.0/zoomInFactor;

  var g = svgDoc.getElementById('viewport');
  try
  {
    var bb = g.getBBox(); // this can throw an exception if css { display: none }
    var tx = (windowWidth-viewWidth*minZoom+8)/(2*minZoom);
    var ty = viewHeight+(windowHeight-viewHeight*minZoom)/(2*minZoom);
    var a = 'scale('+minZoom+') rotate(0) translate('+tx+' '+ty+')';
    g.setAttribute('transform',a);
  }
  catch(e) {}
}

/**
 * Register handlers
 */
function init(evt) 
{
  svgDoc = evt.target.ownerDocument;
  if (top.window && top.window.registerShow) // register show function in html doc for dynamic sections
  {
    top.window.registerShow(sectionId,show);
  }
  show();

  setAttributes(root, {
     "onmousedown" : "handleMouseDown(evt)",
     "onmousemove" : "handleMouseMove(evt)",
     "onmouseup"   : "handleMouseUp(evt)"
  });

  if (window.addEventListener)
  {
    if (navigator.userAgent.toLowerCase().indexOf('webkit') >= 0 || 
        navigator.userAgent.toLowerCase().indexOf("opera") >= 0 || 
        navigator.appVersion.indexOf("MSIE") != -1)
    {
      window.addEventListener('mousewheel', handleMouseWheel, false); // Chrome/Safari/IE9
    }
    else
    {
      window.addEventListener('DOMMouseScroll', handleMouseWheel, false); // Others
    }
  }
}

window.onresize=function()
{
  if (svgDoc) { show(); }
}

/**
 * Instance an SVGPoint object with given event coordinates.
 */
function getEventPoint(evt) 
{
  var p = root.createSVGPoint();
  p.x = evt.clientX;
  p.y = evt.clientY;
  return p;
}

/**
 * Sets the current transform matrix of an element.
 */
function setCTM(element, matrix) 
{
  var s = "matrix(" + matrix.a + "," + matrix.b + "," + matrix.c + "," + matrix.d + "," + matrix.e + "," + matrix.f + ")";
  element.setAttribute("transform", s);
}

/**
 * Sets attributes of an element.
 */
function setAttributes(element, attributes)
{
  for (i in attributes)
    element.setAttributeNS(null, i, attributes[i]);
}

function doZoom(g,point,zoomFactor)
{
  var p = point.matrixTransform(g.getCTM().inverse());
  var k = root.createSVGMatrix().translate(p.x, p.y).scale(zoomFactor).translate(-p.x, -p.y);
  var n = g.getCTM().multiply(k);
  var s = Math.max(n.a,n.d);
  if      (s>maxZoom) n=n.translate(p.x,p.y).scale(maxZoom/s).translate(-p.x,-p.y);
  else if (s<minZoom) n=n.translate(p.x,p.y).scale(minZoom/s).translate(-p.x,-p.y);
  setCTM(g, n);
  stateTf = stateTf.multiply(n.inverse());
}

/**
 * Handle mouse move event.
 */
function handleMouseWheel(evt) 
{
  if (!evt) evt = window.evt;
  if (!evt.shiftKey) return; // only zoom when shift is pressed
  if (evt.preventDefault) evt.preventDefault();
  evt.returnValue = false;

  if (state!='pan')
  {
    var delta;
    if (evt.wheelDelta)
    {
      delta = evt.wheelDelta / 7200; // Opera/Chrome/IE9/Safari
    }
    else
    {
      delta = evt.detail / -180; // Mozilla
    }
    var svgDoc = evt.target.ownerDocument;
    var g = svgDoc.getElementById("viewport");
    var p = getEventPoint(evt);
    doZoom(g,p,1+delta);
  }
}

/**
 * Handle mouse move event.
 */
function handleMouseMove(evt) 
{
  if(evt.preventDefault)
    evt.preventDefault();

  evt.returnValue = false;

  var g = svgDoc.getElementById("viewport");

  if (state == 'pan') 
  {
    // Pan mode
    var p = getEventPoint(evt).matrixTransform(stateTf);
    setCTM(g,stateTf.inverse().translate(p.x - stateOrigin.x, p.y - stateOrigin.y));
  } 
}

/**
 * Handle click event.
 */
function handleMouseDown(evt) 
{
  if(evt.preventDefault)
    evt.preventDefault();
  evt.returnValue = false;
  var g = svgDoc.getElementById("viewport");
  state = 'pan';
  stateTf = g.getCTM().inverse();
  stateOrigin = getEventPoint(evt).matrixTransform(stateTf);
  g.style.cursor = cursorGrab;
}

/**
 * Handle mouse button release event.
 */
function handleMouseUp(evt) 
{
  if (evt.preventDefault) evt.preventDefault();
  evt.returnValue = false;
  var g = svgDoc.getElementById("viewport");
  g.style.cursor = "default";
  // Quit pan mode
  state = '';
}

/**
 * Dumps a matrix to a string (useful for debug).
 */
function dumpMatrix(matrix) 
{
  var s = "[ " + matrix.a + ", " + matrix.c + ", " + matrix.e + "\n  " + matrix.b + ", " + matrix.d + ", " + matrix.f + "\n  0, 0, 1 ]";
  return s;
}

/**
 * Handler for pan buttons
 */
function handlePan(x,y)
{
  var g = svgDoc.getElementById("viewport");
  setCTM(g,g.getCTM().translate(x*20/minZoom,y*20/minZoom));
}

/**
 * Handle reset button
 */
function handleReset()
{
  show();
}

/**
 * Handler for zoom buttons
 */
function handleZoom(evt,direction)
{
  var g = svgDoc.getElementById("viewport");
  var factor = direction=='in' ? zoomInFactor : zoomOutFactor;
  var m = g.getCTM();
  var p = root.createSVGPoint();
  p.x = windowWidth/2;
  p.y = windowHeight/2;
  doZoom(g,p,factor);
}