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1 // A source of tile images of a specific width/height, zoom level range, and some other attributes |
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2 var Source = Class.create({ |
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3 initialize: function (path, tile_width, tile_height, zoom_min, zoom_max) { |
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4 this.path = path; |
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5 this.tile_width = tile_width; |
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6 this.tile_height = tile_height; |
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7 this.zoom_min = zoom_min; |
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8 this.zoom_max = zoom_max; |
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9 |
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10 this.refresh = false; |
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11 this.opt_key = this.opt_value = null; |
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12 }, |
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13 |
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14 // build a URL for the given tile image |
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15 build_url: function (col, row, zl, sw, sh) { |
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16 // two-bit hash (0-4) based on the (col, row) |
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17 var hash = ( (col % 2) << 1 | (row % 2) ) + 1; |
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18 |
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19 // the subdomain to use |
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20 var subdomain = ""; |
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21 |
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22 if (0) |
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23 subdomain = "tile" + hash + "."; |
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24 |
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25 // the (x, y) co-ordinates |
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26 var x = col * this.tile_width; |
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27 var y = row * this.tile_height; |
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28 |
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29 var url = this.path + "?x=" + x + "&y=" + y + "&z=" + zl + "&sw=" + sw + "&sh=" + sh; |
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30 |
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31 if (this.refresh) |
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32 url += "&ts=" + new Date().getTime(); |
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33 |
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34 if (this.opt_key && this.opt_value) |
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35 url += "&" + this.opt_key + "=" + this.opt_value; |
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36 |
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37 return url; |
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38 }, |
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39 }); |
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40 |
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41 // a viewport that contains a substrate which contains several zoom layers which contain many tiles |
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42 var Viewport = Class.create({ |
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43 initialize: function (source, viewport_id) { |
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44 this.source = source; |
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45 |
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46 this.id = viewport_id; |
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47 this.div = $(viewport_id); |
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48 this.substrate = this.div.down("div.substrate"); |
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49 |
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50 // the stack of zoom levels |
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51 this.zoom_layers = []; |
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52 |
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53 // pre-populate the stack |
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54 for (var zoom_level = source.zoom_min; zoom_level <= source.zoom_max; zoom_level++) { |
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55 var zoom_layer = new ZoomLayer(source, zoom_level); |
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56 |
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57 this.substrate.appendChild(zoom_layer.div); |
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58 this.zoom_layers[zoom_level] = zoom_layer; |
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59 } |
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60 |
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61 // make the substrate draggable |
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62 this.draggable = new Draggable(this.substrate, { |
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63 onStart: this.on_scroll_start.bind(this), |
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64 onDrag: this.on_scroll_move.bind(this), |
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65 onEnd: this.on_scroll_end.bind(this), |
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66 }); |
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67 |
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68 // event handlers |
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69 Event.observe(this.substrate, "dblclick", this.on_dblclick.bindAsEventListener(this)); |
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70 Event.observe(this.substrate, "mousewheel", this.on_mousewheel.bindAsEventListener(this)); |
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71 Event.observe(this.substrate, "DOMMouseScroll", this.on_mousewheel.bindAsEventListener(this)); // mozilla |
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72 Event.observe(document, "resize", this.on_resize.bindAsEventListener(this)); |
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73 |
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74 // load initial view |
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75 this.update_size(); |
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76 |
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77 // this sets the scroll offsets, zoom level, and loads the tiles |
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78 this.zoom_to(0, 0, 0); |
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79 }, |
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80 |
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81 /* event handlers */ |
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82 |
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83 // window resized |
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84 on_resize: function (ev) { |
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85 this.update_size(); |
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86 this.update_tiles(); |
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87 }, |
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88 |
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89 // double-click handler |
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90 on_dblclick: function (ev) { |
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91 var offset = this.event_offset(ev); |
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92 |
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93 this.zoom_center_to( |
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94 this.scroll_x + offset.x, |
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95 this.scroll_y + offset.y, |
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96 1 // zoom in |
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97 ); |
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98 }, |
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99 |
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100 // mousewheel handler |
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101 on_mousewheel: function (ev) { |
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102 // this works in very weird ways, so it's based on code from http://adomas.org/javascript-mouse-wheel/ |
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103 // (it didn't include any license, so this is written out manually) |
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104 var delta; |
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105 |
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106 // this is browser-dependant... |
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107 if (ev.wheelDelta) { |
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108 // IE + Opera |
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109 delta = ev.wheelDelta; |
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110 |
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111 if (window.opera) { |
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112 // Opera, but apparently not newer versions? |
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113 //delta = -delta; |
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114 } |
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115 |
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116 } else if (ev.detail) { |
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117 // Mozilla |
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118 delta = -ev.detail; |
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119 |
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120 } else { |
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121 // mousewheel not supported... |
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122 return; |
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123 |
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124 } |
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125 |
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126 // don't scroll the page |
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127 if (ev.preventDefault) |
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128 ev.preventDefault(); |
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129 |
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130 // delta > 0 : scroll up, zoom in |
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131 // delta < 0 : scroll down, zoom out |
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132 delta = delta < 0 ? -1 : 1; |
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133 |
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134 // Firefox's DOMMouseEvent's pageX/Y attributes are broken. layerN is for mozilla, offsetN for IE, seems to work |
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135 |
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136 // absolute location of the cursor |
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137 var x = parseInt(ev.target.style.left) + (ev.layerX ? ev.layerX : ev.offsetX); |
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138 var y = parseInt(ev.target.style.top) + (ev.layerY ? ev.layerY : ev.offsetY); |
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139 |
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140 // zoom \o/ |
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141 this.zoom_center_to(x, y, delta); |
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142 }, |
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143 |
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144 // substrate scroll was started |
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145 on_scroll_start: function (ev) { |
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146 |
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147 }, |
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148 |
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149 // substrate was scrolled, update scroll_{x,y}, and then update tiles after 100ms |
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150 on_scroll_move: function (ev) { |
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151 this.update_scroll(); |
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152 this.update_after_timeout(); |
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153 }, |
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154 |
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155 // substrate scroll was ended, update tiles now |
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156 on_scroll_end: function (ev) { |
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157 this.update_now(); |
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158 }, |
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159 |
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160 /* get state */ |
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161 |
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162 // return the absolute (x, y) coords of the given event inside the viewport |
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163 event_offset: function (ev) { |
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164 var offset = this.div.cumulativeOffset(); |
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165 |
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166 return { |
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167 x: ev.pointerX() - offset.left, |
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168 y: ev.pointerY() - offset.top |
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169 }; |
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170 }, |
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171 |
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172 /* modify state */ |
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173 |
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174 // scroll the view to place the given absolute (x, y) co-ordinate at the top left |
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175 scroll_to: function (x, y) { |
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176 // update it via the style |
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177 this.substrate.style.top = "-" + y + "px"; |
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178 this.substrate.style.left = "-" + x + "px"; |
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179 |
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180 // update these as well |
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181 this.scroll_x = x; |
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182 this.scroll_y = y; |
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183 }, |
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184 |
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185 // scroll the view to place the given absolute (x, y) co-ordinate at the center |
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186 scroll_center_to: function (x, y) { |
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187 return this.scroll_to( |
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188 x - this.center_offset_x, |
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189 y - this.center_offset_y |
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190 ); |
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191 }, |
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192 |
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193 // zoom à la delta such that the given (zoomed) absolute (x, y) co-ordinates will be at the top left |
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194 zoom_scaled: function (x, y, delta) { |
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195 if (!this.update_zoom(delta)) |
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196 return false; |
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197 |
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198 // scroll to the new position |
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199 this.scroll_to(x, y); |
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200 |
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201 // update view |
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202 // XXX: ... |
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203 this.update_after_timeout(); |
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204 |
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205 return true; |
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206 }, |
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207 |
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208 // zoom à la delta such that the given (current) absolute (x, y) co-ordinates will be at the top left |
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209 zoom_to: function (x, y, delta) { |
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210 return this.zoom_scaled( |
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211 scaleByZoomDelta(x, delta), |
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212 scaleByZoomDelta(y, delta), |
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213 delta |
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214 ); |
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215 }, |
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216 |
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217 // zoom à la delta such that the given (current) absolute (x, y) co-ordinates will be at the center |
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218 zoom_center_to: function (x, y, delta) { |
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219 return this.zoom_scaled( |
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220 scaleByZoomDelta(x, delta) - this.center_offset_x, |
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221 scaleByZoomDelta(y, delta) - this.center_offset_y, |
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222 delta |
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223 ); |
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224 }, |
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225 |
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226 |
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227 /* update view/state to reflect reality */ |
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228 |
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229 // figure out the viewport dimensions |
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230 update_size: function () { |
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231 this.view_width = this.div.getWidth(); |
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232 this.view_height = this.div.getHeight(); |
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233 |
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234 this.center_offset_x = Math.floor(this.view_width / 2); |
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235 this.center_offset_y = Math.floor(this.view_height / 2); |
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236 }, |
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237 |
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238 // figure out the scroll offset as absolute pixel co-ordinates at the top left |
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239 update_scroll: function() { |
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240 this.scroll_x = -parseInt(this.substrate.style.left); |
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241 this.scroll_y = -parseInt(this.substrate.style.top); |
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242 }, |
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243 |
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244 // wiggle the ZoomLevels around to match the current zoom level |
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245 update_zoom: function(delta) { |
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246 if (!this.zoom_layer) { |
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247 // first zoom operation |
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248 |
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249 // is the new zoom level valid? |
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250 if (!this.zoom_layers[delta]) |
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251 return false; |
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252 |
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253 // set the zoom layyer |
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254 this.zoom_layer = this.zoom_layers[delta]; |
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255 |
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256 // enable it |
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257 this.zoom_layer.enable(11); |
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258 |
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259 // no need to .update_tiles or anything like that |
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260 |
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261 } else { |
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262 // is the new zoom level valid? |
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263 if (!this.zoom_layers[this.zoom_layer.level + delta]) |
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264 return false; |
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265 |
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266 var zoom_old = this.zoom_layer; |
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267 var zoom_new = this.zoom_layers[this.zoom_layer.level + delta]; |
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268 |
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269 // XXX: ugly hack |
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270 if (this.zoom_timer) { |
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271 clearTimeout(this.zoom_timer); |
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272 this.zoom_timer = null; |
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273 } |
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274 |
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275 // get other zoom layers out of the way |
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276 this.zoom_layers.each(function (zl) { |
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277 zl.disable(); |
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278 }); |
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279 |
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280 // update the zoom layer |
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281 this.zoom_layer = zoom_new; |
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282 |
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283 // apply new z-indexes, preferr the current one over the new one |
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284 zoom_new.enable(11); |
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285 zoom_old.enable(10); |
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286 |
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287 // resize the tiles in the two zoom layers |
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288 zoom_new.update_tiles(zoom_new.level); |
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289 zoom_old.update_tiles(zoom_old.level); |
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290 |
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291 // XXX: ugly hack |
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292 this.zoom_timer = setTimeout(function () { zoom_old.disable()}, 1000); |
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293 } |
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294 |
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295 return true; |
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296 }, |
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297 |
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298 // ensure that all tiles that are currently visible are loaded |
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299 update_tiles: function() { |
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300 // short names for some vars... |
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301 var x = this.scroll_x; |
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302 var y = this.scroll_y; |
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303 var sw = this.view_width; |
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304 var sh = this.view_height; |
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305 var tw = this.source.tile_width; |
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306 var th = this.source.tile_height; |
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307 var zl = this.zoom_layer.level; |
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308 |
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309 // figure out what set of columns are visible |
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310 var start_col = Math.max(0, Math.floor(x / tw)); |
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311 var start_row = Math.max(0, Math.floor(y / th)); |
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312 var end_col = Math.floor((x + sw) / tw); |
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313 var end_row = Math.floor((y + sh) / th); |
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314 |
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315 // loop through all those tiles |
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316 for (var col = start_col; col <= end_col; col++) { |
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317 for (var row = start_row; row <= end_row; row++) { |
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318 // the tile's id |
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319 var id = "tile_" + this.zoom_layer.level + "_" + col + "_" + row; |
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320 |
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321 // does the element exist already? |
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322 var t = $(id); |
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323 |
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324 if (!t) { |
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325 // build a new tile |
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326 t = Builder.node("img", { |
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327 src: this.source.build_url(col, row, zl, sw, sh), |
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328 id: id, |
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329 title: "(" + col + ", " + row + ")", |
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330 // style set later |
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331 } |
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332 ); |
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333 |
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334 // set the CSS style stuff |
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335 t.style.top = th * row; |
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336 t.style.left = tw * col; |
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337 t.style.display = "none"; |
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338 |
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339 // wait for it to load |
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340 Event.observe(t, "load", _tile_loaded.bindAsEventListener(t)); |
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341 |
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342 // store the col/row |
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343 t.__col = col; |
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344 t.__row = row; |
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345 |
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346 // add it to the zoom layer |
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347 this.zoom_layer.add_tile(t); |
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348 |
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349 } else if (this.source.reload) { |
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350 // force the tile to reload |
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351 touch_tile(t, col, row); |
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352 |
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353 } |
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354 } |
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355 } |
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356 |
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357 /* XXX: fixme |
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358 // update the link-to-this-page thing |
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359 document.location.hash = "#goto_" + (x + g_w_half) + ":" + g_w + "_" + (y + g_h_half) + ":" + g_h + "_" + g_z; |
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360 */ |
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361 |
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362 }, |
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363 |
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364 // do update_tiles after 100ms, unless we are called again |
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365 update_after_timeout: function () { |
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366 this._update_idle = false; |
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367 |
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368 if (this._update_timeout) |
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369 clearTimeout(this._update_timeout); |
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370 |
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371 this._update_timeout = setTimeout(this._update_timeout_trigger.bind(this), 100); |
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372 }, |
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373 |
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374 _update_timeout_trigger: function () { |
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375 this._update_idle = true; |
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376 |
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377 this.update_tiles(); |
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378 }, |
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379 |
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380 // call update_tiles if it hasn't been called due to update_after_timeout |
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381 update_now: function () { |
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382 if (this._update_timeout) |
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383 clearTimeout(this._update_timeout); |
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384 |
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385 if (!this._update_idle) |
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386 this.update_tiles(); |
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387 }, |
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388 |
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389 }); |
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390 |
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391 // used by Viewport.update_tiles to make a tile visible after it has loaded |
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392 function _tile_loaded (ev) { |
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393 this.style.display = "block"; |
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394 } |
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395 |
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396 // a zoom layer containing the tiles for one zoom level |
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397 var ZoomLayer = Class.create({ |
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398 initialize: function (source, zoom_level) { |
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399 this.source = source; |
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400 this.level = zoom_level; |
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401 this.div = Builder.node("div", { id: "zl_" + this.level, style: "position: relative; display: none;"}); |
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402 |
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403 // our tiles |
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404 this.tiles = []; |
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405 }, |
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406 |
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407 // add a tile to this zoom layer |
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408 add_tile: function (tile) { |
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409 this.div.appendChild(tile); |
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410 this.tiles.push(tile); |
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411 }, |
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412 |
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413 // make this zoom layer visible with the given z-index |
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414 enable: function (z_index) { |
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415 this.div.style.zIndex = z_index; |
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416 this.div.show(); |
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417 }, |
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418 |
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419 // hide this zoom layer |
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420 disable: function (z_index) { |
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421 this.div.hide(); |
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422 }, |
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423 |
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424 // update the tiles in this zoom layer so that they are in the correct position and of the correct size when |
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425 // viewed with the given zoom level |
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426 update_tiles: function (zoom_level) { |
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427 var zd = zoom_level - this.level; |
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428 |
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429 var tw = scaleByZoomDelta(this.source.tile_width, zd); |
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430 var th = scaleByZoomDelta(this.source.tile_height, zd); |
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431 |
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432 var tiles = this.tiles; |
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433 var tiles_len = tiles.length; |
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434 var t, ts; |
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435 |
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436 for (var i = 0; i < tiles_len; i++) { |
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437 t = tiles[i]; |
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438 ts = t.style; |
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439 |
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440 ts.width = tw; |
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441 ts.height = th; |
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442 ts.top = th*t.__row; |
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443 ts.left = tw*t.__col; |
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444 } |
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445 }, |
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446 |
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447 |
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448 |
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449 }); |
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450 |
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451 // scale the given co-ordinate by a zoom delta. If we zoom in (dz > 0), n will become larger, and if we zoom |
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452 // out (dz < 0), n will become smaller. |
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453 function scaleByZoomDelta (n, dz) { |
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454 if (dz > 0) |
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455 return n << dz; |
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456 else |
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457 return n >> -dz; |
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458 } |
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459 |