--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/static/tiles.js Tue May 05 19:37:32 2009 +0300
@@ -0,0 +1,473 @@
+// A source of tile images of a specific width/height, zoom level range, and some other attributes
+var Source = Class.create({
+ initialize: function (path, tile_width, tile_height, zoom_min, zoom_max) {
+ // relative path?
+ if (path.substring(0, 1) != "/") {
+ // current document path
+ _path = document.location.pathname;
+
+ // as relative
+ _path = _path.substring(0, _path.lastIndexOf("/"));
+
+ // conact to make absolute path
+ path = _path + "/" + path
+
+ }
+
+ // store
+ this.path = path;
+ this.tile_width = tile_width;
+ this.tile_height = tile_height;
+ this.zoom_min = zoom_min;
+ this.zoom_max = zoom_max;
+
+ this.refresh = false;
+ this.opt_key = this.opt_value = null;
+ },
+
+ // build a URL for the given tile image
+ build_url: function (col, row, zl, sw, sh) {
+ // two-bit hash (0-4) based on the (col, row)
+ var hash = ( (col % 2) << 1 | (row % 2) ) + 1;
+
+ // the subdomain to use
+ var subdomain = "";
+
+ if (0)
+ subdomain = "tile" + hash + ".";
+
+ // the (x, y) co-ordinates
+ var x = col * this.tile_width;
+ var y = row * this.tile_height;
+
+ var url = "http://" + subdomain + document.location.host + this.path + "?x=" + x + "&y=" + y + "&z=" + zl + "&sw=" + sw + "&sh=" + sh;
+
+ if (this.refresh)
+ url += "&ts=" + new Date().getTime();
+
+ if (this.opt_key && this.opt_value)
+ url += "&" + this.opt_key + "=" + this.opt_value;
+
+ return url;
+ },
+});
+
+// a viewport that contains a substrate which contains several zoom layers which contain many tiles
+var Viewport = Class.create({
+ initialize: function (source, viewport_id) {
+ this.source = source;
+
+ this.id = viewport_id;
+ this.div = $(viewport_id);
+ this.substrate = this.div.down("div.substrate");
+
+ // the stack of zoom levels
+ this.zoom_layers = [];
+
+ // pre-populate the stack
+ for (var zoom_level = source.zoom_min; zoom_level <= source.zoom_max; zoom_level++) {
+ var zoom_layer = new ZoomLayer(source, zoom_level);
+
+ this.substrate.appendChild(zoom_layer.div);
+ this.zoom_layers[zoom_level] = zoom_layer;
+ }
+
+ // make the substrate draggable
+ this.draggable = new Draggable(this.substrate, {
+ onStart: this.on_scroll_start.bind(this),
+ onDrag: this.on_scroll_move.bind(this),
+ onEnd: this.on_scroll_end.bind(this),
+ });
+
+ // event handlers
+ Event.observe(this.substrate, "dblclick", this.on_dblclick.bindAsEventListener(this));
+ Event.observe(this.substrate, "mousewheel", this.on_mousewheel.bindAsEventListener(this));
+ Event.observe(this.substrate, "DOMMouseScroll", this.on_mousewheel.bindAsEventListener(this)); // mozilla
+ Event.observe(document, "resize", this.on_resize.bindAsEventListener(this));
+
+ // load initial view
+ this.update_size();
+
+ // this sets the scroll offsets, zoom level, and loads the tiles
+ this.zoom_to(0, 0, 0);
+ },
+
+ /* event handlers */
+
+ // window resized
+ on_resize: function (ev) {
+ this.update_size();
+ this.update_tiles();
+ },
+
+ // double-click handler
+ on_dblclick: function (ev) {
+ var offset = this.event_offset(ev);
+
+ this.zoom_center_to(
+ this.scroll_x + offset.x,
+ this.scroll_y + offset.y,
+ 1 // zoom in
+ );
+ },
+
+ // mousewheel handler
+ on_mousewheel: function (ev) {
+ // this works in very weird ways, so it's based on code from http://adomas.org/javascript-mouse-wheel/
+ // (it didn't include any license, so this is written out manually)
+ var delta;
+
+ // this is browser-dependant...
+ if (ev.wheelDelta) {
+ // IE + Opera
+ delta = ev.wheelDelta;
+
+ if (window.opera) {
+ // Opera, but apparently not newer versions?
+ //delta = -delta;
+ }
+
+ } else if (ev.detail) {
+ // Mozilla
+ delta = -ev.detail;
+
+ } else {
+ // mousewheel not supported...
+ return;
+
+ }
+
+ // don't scroll the page
+ if (ev.preventDefault)
+ ev.preventDefault();
+
+ // delta > 0 : scroll up, zoom in
+ // delta < 0 : scroll down, zoom out
+ delta = delta < 0 ? -1 : 1;
+
+ // Firefox's DOMMouseEvent's pageX/Y attributes are broken. layerN is for mozilla, offsetN for IE, seems to work
+
+ // absolute location of the cursor
+ var x = parseInt(ev.target.style.left) + (ev.layerX ? ev.layerX : ev.offsetX);
+ var y = parseInt(ev.target.style.top) + (ev.layerY ? ev.layerY : ev.offsetY);
+
+ // zoom \o/
+ this.zoom_center_to(x, y, delta);
+ },
+
+ // substrate scroll was started
+ on_scroll_start: function (ev) {
+
+ },
+
+ // substrate was scrolled, update scroll_{x,y}, and then update tiles after 100ms
+ on_scroll_move: function (ev) {
+ this.update_scroll();
+ this.update_after_timeout();
+ },
+
+ // substrate scroll was ended, update tiles now
+ on_scroll_end: function (ev) {
+ this.update_now();
+ },
+
+ /* get state */
+
+ // return the absolute (x, y) coords of the given event inside the viewport
+ event_offset: function (ev) {
+ var offset = this.div.cumulativeOffset();
+
+ return {
+ x: ev.pointerX() - offset.left,
+ y: ev.pointerY() - offset.top
+ };
+ },
+
+ /* modify state */
+
+ // scroll the view to place the given absolute (x, y) co-ordinate at the top left
+ scroll_to: function (x, y) {
+ // update it via the style
+ this.substrate.style.top = "-" + y + "px";
+ this.substrate.style.left = "-" + x + "px";
+
+ // update these as well
+ this.scroll_x = x;
+ this.scroll_y = y;
+ },
+
+ // scroll the view to place the given absolute (x, y) co-ordinate at the center
+ scroll_center_to: function (x, y) {
+ return this.scroll_to(
+ x - this.center_offset_x,
+ y - this.center_offset_y
+ );
+ },
+
+ // zoom à la delta such that the given (zoomed) absolute (x, y) co-ordinates will be at the top left
+ zoom_scaled: function (x, y, delta) {
+ if (!this.update_zoom(delta))
+ return false;
+
+ // scroll to the new position
+ this.scroll_to(x, y);
+
+ // update view
+ // XXX: ...
+ this.update_after_timeout();
+
+ return true;
+ },
+
+ // zoom à la delta such that the given (current) absolute (x, y) co-ordinates will be at the top left
+ zoom_to: function (x, y, delta) {
+ return this.zoom_scaled(
+ scaleByZoomDelta(x, delta),
+ scaleByZoomDelta(y, delta),
+ delta
+ );
+ },
+
+ // zoom à la delta such that the given (current) absolute (x, y) co-ordinates will be at the center
+ zoom_center_to: function (x, y, delta) {
+ return this.zoom_scaled(
+ scaleByZoomDelta(x, delta) - this.center_offset_x,
+ scaleByZoomDelta(y, delta) - this.center_offset_y,
+ delta
+ );
+ },
+
+
+ /* update view/state to reflect reality */
+
+ // figure out the viewport dimensions
+ update_size: function () {
+ this.view_width = this.div.getWidth();
+ this.view_height = this.div.getHeight();
+
+ this.center_offset_x = Math.floor(this.view_width / 2);
+ this.center_offset_y = Math.floor(this.view_height / 2);
+ },
+
+ // figure out the scroll offset as absolute pixel co-ordinates at the top left
+ update_scroll: function() {
+ this.scroll_x = -parseInt(this.substrate.style.left);
+ this.scroll_y = -parseInt(this.substrate.style.top);
+ },
+
+ // wiggle the ZoomLevels around to match the current zoom level
+ update_zoom: function(delta) {
+ if (!this.zoom_layer) {
+ // first zoom operation
+
+ // is the new zoom level valid?
+ if (!this.zoom_layers[delta])
+ return false;
+
+ // set the zoom layyer
+ this.zoom_layer = this.zoom_layers[delta];
+
+ // enable it
+ this.zoom_layer.enable(11);
+
+ // no need to .update_tiles or anything like that
+
+ } else {
+ // is the new zoom level valid?
+ if (!this.zoom_layers[this.zoom_layer.level + delta])
+ return false;
+
+ var zoom_old = this.zoom_layer;
+ var zoom_new = this.zoom_layers[this.zoom_layer.level + delta];
+
+ // XXX: ugly hack
+ if (this.zoom_timer) {
+ clearTimeout(this.zoom_timer);
+ this.zoom_timer = null;
+ }
+
+ // get other zoom layers out of the way
+ this.zoom_layers.each(function (zl) {
+ zl.disable();
+ });
+
+ // update the zoom layer
+ this.zoom_layer = zoom_new;
+
+ // apply new z-indexes, preferr the current one over the new one
+ zoom_new.enable(11);
+ zoom_old.enable(10);
+
+ // resize the tiles in the two zoom layers
+ zoom_new.update_tiles(zoom_new.level);
+ zoom_old.update_tiles(zoom_old.level);
+
+ // XXX: ugly hack
+ this.zoom_timer = setTimeout(function () { zoom_old.disable()}, 1000);
+ }
+
+ return true;
+ },
+
+ // ensure that all tiles that are currently visible are loaded
+ update_tiles: function() {
+ // short names for some vars...
+ var x = this.scroll_x;
+ var y = this.scroll_y;
+ var sw = this.view_width;
+ var sh = this.view_height;
+ var tw = this.source.tile_width;
+ var th = this.source.tile_height;
+ var zl = this.zoom_layer.level;
+
+ // figure out what set of columns are visible
+ var start_col = Math.max(0, Math.floor(x / tw));
+ var start_row = Math.max(0, Math.floor(y / th));
+ var end_col = Math.floor((x + sw) / tw);
+ var end_row = Math.floor((y + sh) / th);
+
+ // loop through all those tiles
+ for (var col = start_col; col <= end_col; col++) {
+ for (var row = start_row; row <= end_row; row++) {
+ // the tile's id
+ var id = "tile_" + this.zoom_layer.level + "_" + col + "_" + row;
+
+ // does the element exist already?
+ var t = $(id);
+
+ if (!t) {
+ // build a new tile
+ t = Builder.node("img", {
+ src: this.source.build_url(col, row, zl, sw, sh),
+ id: id,
+ title: "(" + col + ", " + row + ")",
+ // style set later
+ }
+ );
+
+ // set the CSS style stuff
+ t.style.top = th * row;
+ t.style.left = tw * col;
+ t.style.display = "none";
+
+ // wait for it to load
+ Event.observe(t, "load", _tile_loaded.bindAsEventListener(t));
+
+ // store the col/row
+ t.__col = col;
+ t.__row = row;
+
+ // add it to the zoom layer
+ this.zoom_layer.add_tile(t);
+
+ } else if (this.source.reload) {
+ // force the tile to reload
+ touch_tile(t, col, row);
+
+ }
+ }
+ }
+
+/* XXX: fixme
+ // update the link-to-this-page thing
+ document.location.hash = "#goto_" + (x + g_w_half) + ":" + g_w + "_" + (y + g_h_half) + ":" + g_h + "_" + g_z;
+*/
+
+ },
+
+ // do update_tiles after 100ms, unless we are called again
+ update_after_timeout: function () {
+ this._update_idle = false;
+
+ if (this._update_timeout)
+ clearTimeout(this._update_timeout);
+
+ this._update_timeout = setTimeout(this._update_timeout_trigger.bind(this), 100);
+ },
+
+ _update_timeout_trigger: function () {
+ this._update_idle = true;
+
+ this.update_tiles();
+ },
+
+ // call update_tiles if it hasn't been called due to update_after_timeout
+ update_now: function () {
+ if (this._update_timeout)
+ clearTimeout(this._update_timeout);
+
+ if (!this._update_idle)
+ this.update_tiles();
+ },
+
+});
+
+// used by Viewport.update_tiles to make a tile visible after it has loaded
+function _tile_loaded (ev) {
+ this.style.display = "block";
+}
+
+// a zoom layer containing the tiles for one zoom level
+var ZoomLayer = Class.create({
+ initialize: function (source, zoom_level) {
+ this.source = source;
+ this.level = zoom_level;
+ this.div = Builder.node("div", { id: "zl_" + this.level, style: "position: relative; display: none;"});
+
+ // our tiles
+ this.tiles = [];
+ },
+
+ // add a tile to this zoom layer
+ add_tile: function (tile) {
+ this.div.appendChild(tile);
+ this.tiles.push(tile);
+ },
+
+ // make this zoom layer visible with the given z-index
+ enable: function (z_index) {
+ this.div.style.zIndex = z_index;
+ this.div.show();
+ },
+
+ // hide this zoom layer
+ disable: function (z_index) {
+ this.div.hide();
+ },
+
+ // update the tiles in this zoom layer so that they are in the correct position and of the correct size when
+ // viewed with the given zoom level
+ update_tiles: function (zoom_level) {
+ var zd = zoom_level - this.level;
+
+ var tw = scaleByZoomDelta(this.source.tile_width, zd);
+ var th = scaleByZoomDelta(this.source.tile_height, zd);
+
+ var tiles = this.tiles;
+ var tiles_len = tiles.length;
+ var t, ts;
+
+ for (var i = 0; i < tiles_len; i++) {
+ t = tiles[i];
+ ts = t.style;
+
+ ts.width = tw;
+ ts.height = th;
+ ts.top = th*t.__row;
+ ts.left = tw*t.__col;
+ }
+ },
+
+
+
+});
+
+// scale the given co-ordinate by a zoom delta. If we zoom in (dz > 0), n will become larger, and if we zoom
+// out (dz < 0), n will become smaller.
+function scaleByZoomDelta (n, dz) {
+ if (dz > 0)
+ return n << dz;
+ else
+ return n >> -dz;
+}
+