workspace/plasma/scriptengines/webkit/dashboard/AppleClasses/AppleScrollArea.js

   1 /*
   2  * Copyright 2008 Stefan Buller <hikingpete@cain.afraid.org>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) version 3, or any
   8  * later version accepted by the membership of KDE e.V. (or its
   9  * successor approved by the membership of KDE e.V.), which shall
  10  * act as a proxy defined in Section 6 of version 3 of the license.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 function AppleScrollArea(content) {
  22         for (var i = 0; i < arguments.length; i++) {
  23                 this.addScrollbar(arguments[i]);
  24         }
  25         var that=this;
  26         var handler=function(e) {
  27                 switch(e.which) {
  28                         case 37: //left
  29                                 that.horizontalScrollTo(that.content.scrollLeft -
  30                                                 that.singlepressScrollPixels);
  31                                 break;
  32                         case 38: //up
  33                                 that.verticalScrollTo(that.content.scrollTop -
  34                                                 that.singlepressScrollPixels);
  35                                 break;
  36                         case 39: //right
  37                                 that.horizontalScrollTo(that.content.scrollLeft +
  38                                                 that.singlepressScrollPixels);
  39                                 break;
  40                         case 40: //down
  41                                 that.verticalScrollTo(that.content.scrollTop +
  42                                                 that.singlepressScrollPixels);
  43                                 break;
  44                         default:
  45                                 //the event may contiue to propagate
  46                                 return true;
  47                 }
  48                 //arrest propagation
  49                 return false;
  50         }
  51         content.addEventListener('keydown',handler,false);
  52
  53         //Apple mandated properties that must be reacted to.
  54         this.scrollsVertically = false;
  55         this.scrollsHorizontally = false;
  56         this.singlepressScrollPixels = 10; //Somebody change this. Please.
  57
  58         //Apple mandated properties that are `read only'.
  59         this.viewHeight = content.clientHeight;
  60         this.viewToContentHeightRatio = content.clientHeight / content.scrollHeight;
  61         this.viewWidth = content.clientWidth;
  62         this.viewToContentWidthRatio = content.clientWidth / content.scrollWidth;
  63         //I'm worried that the scrollHeight/Width could change on me. If that turns
  64         //out to be a problem, then getters would be the way to go.
  65
  66         //extras
  67         this.scrollbars = [];
  68         this.content = content;
  69 }
  70
  71 AppleScrollArea.prototype.addScrollbar = function(scrollbar) {
  72         this.scrollbars.push(scrollbar);
  73         scrollbar.setScrollArea(this);
  74 }
  75
  76 AppleScrollArea.prototype.removeScrollbar = function(scrollbar) {
  77         this.scrollbars.filter(function(element){return (element === scrollbar);});
  78         scrollbar.setScrollArea(null); //Just a guess. This might not be right.
  79 }
  80
  81 AppleScrollArea.prototype.remove = function() {
  82         //Remove the div, or remove the effects of AppleScrollArea?
  83         //Perhaps this can all be replaced with a simple removeChild()
  84         content.scrollTop = 0;
  85         content.scrollLeft = 0;
  86         for (var i = 0; i < this.scrollbars.length; i++) {
  87                 this.scrollbars[i].remove();
  88                 delete this.scrollbars[i];
  89         }
  90         delete this;
  91 }
  92
  93 AppleScrollArea.prototype.reveal = function(element) {
  94         //First we find it
  95         var distX = 0;
  96         var distY = 0;
  97         var el = element;
  98         while (el !== this.content) {
  99                 distX += (+el.offsetTop);
 100                 distY += (+el.offsetLeft);
 101                 el = el.parentNode;
 102                 if (el == null) {
 103                         throw "Target element not in ScrollArea.";
 104                 }
 105         }
 106
 107         this.verticalScrollTo(distY);
 108         this.horizontalScrollTo(distX);
 109 }
 110
 111 AppleScrollArea.prototype.focus = function() {
 112         this.content.focus();
 113 }
 114
 115 AppleScrollArea.prototype.blur = function() {
 116         this.content.blur();
 117 }
 118
 119 AppleScrollArea.prototype.verticalScrollTo = function(position) {
 120         this.scrollTop = position;
 121 }
 122
 123 AppleScrollArea.prototype.horizontalScrollTo = function(position) {
 124         this.scrollLeft = position;
 125 }
 126
 127