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Refactored the code based on review comments

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achu1998 2025-04-17 01:32:51 +09:30
parent 8bcd611a33
commit 9f86a1fe08
2 changed files with 50 additions and 16 deletions
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4
src/tiledimage.js
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@ -267,9 +267,7 @@ $.extend($.TiledImage.prototype, $.EventSource.prototype, /** @lends OpenSeadrag
if (this.getFullyLoaded()) {
setTimeout(callback, 1); // Asynchronous execution
} else {
this.addOnceHandler('fully-loaded-change', function() {
callback.call(this); // Maintain context
});
this.addOnceHandler('fully-loaded-change', callback); // Maintain context
}
},

62
src/viewer.js
View file

@ -366,7 +366,20 @@ $.Viewer = function( options ) {
viewer: this
});
var self = this; // Capture viewer instance
/**
* Handles 'add-item' events from the viewer's world.
* - Attaches a 'fully-loaded-change' event handler to the newly added TiledImage.
* - The handler monitors the TiledImage's loading state and, when triggered,
* checks whether all TiledImages in the viewer are fully loaded.
* - If the aggregate fully-loaded state changes, raises a 'fully-loaded-change'
* event at the viewer level with the new state.
* - The handler reference is stored on the TiledImage instance for proper
* cleanup when the TiledImage is removed (see the corresponding 'remove-item' handler).
* @function
* @listens OpenSeadragon.World#add-item
* @param {Object} event - Event object containing the added TiledImage
* @param {OpenSeadragon.TiledImage} event.item - Newly added TiledImage instance
*/
this.world.addHandler('add-item', function(event) {
// For backwards compatibility, we maintain the source property
_this.source = _this.world.getItemAt(0).source;
@ -377,21 +390,42 @@ $.Viewer = function( options ) {
_this._updateRequestId = scheduleUpdate( _this, updateMulti );
}
// Attaches a handler to monitor individual TiledImage loading states
// propagate aggregate viewer-level fully-loaded status changes.
var tiledImage = event.item;
tiledImage.addHandler('fully-loaded-change', function() {
// Check aggregate loading state across all TiledImages
var newFullyLoaded = self.areAllFullyLoaded();
// Only trigger event if viewer's loading state has changed
if (newFullyLoaded !== self._fullyLoaded) {
self._fullyLoaded = newFullyLoaded;
self.raiseEvent('fully-loaded-change', { fullyLoaded: newFullyLoaded });
var fullyLoadedHandler = function() {
var newFullyLoaded = _this._areAllFullyLoaded();
if (newFullyLoaded !== _this._fullyLoaded) {
_this._fullyLoaded = newFullyLoaded;
_this.raiseEvent('fully-loaded-change', { fullyLoaded: newFullyLoaded });
}
});
};
tiledImage._fullyLoadedHandler = fullyLoadedHandler;
tiledImage.addHandler('fully-loaded-change', fullyLoadedHandler);
});
/**
* Handles 'remove-item' events from the viewer's world.
*
* - Safely removes the 'fully-loaded-change' event handler previously attached to the TiledImage
* when it was added, preventing memory leaks and unintended event firing after removal.
* - Deletes the handler reference from the TiledImage instance for cleanliness.
* - Maintains backwards compatibility by updating the viewer's `source` property
* to reflect the current first item in the world, or null if empty.
* - Forces a redraw of the viewer to ensure visual consistency after item removal.
*
* @function
* @listens OpenSeadragon.World#remove-item
* @param {Object} event - Event object containing the removed TiledImage
* @param {OpenSeadragon.TiledImage} event.item - TiledImage instance being removed
*/
this.world.addHandler('remove-item', function(event) {
var tiledImage = event.item;
// SAFE cleanup with existence check
if (tiledImage._fullyLoadedHandler) {
tiledImage.removeHandler('fully-loaded-change', tiledImage._fullyLoadedHandler);
delete tiledImage._fullyLoadedHandler; // Remove the reference
}
// For backwards compatibility, we maintain the source property
if (_this.world.getItemCount()) {
_this.source = _this.world.getItemAt(0).source;
@ -580,9 +614,11 @@ $.extend( $.Viewer.prototype, $.EventSource.prototype, $.ControlDock.prototype,
/**
* Checks whether all TiledImage instances in the viewer's world are fully loaded.
* This determines if the entire viewer content is ready for optimal display without partial tile loading.
* @returns {Boolean} True if all TiledImages report being fully loaded, false if any image still has pending tiles
* @private
* @returns {Boolean} True if all TiledImages report being fully loaded,
* false if any image still has pending tiles
*/
areAllFullyLoaded: function() {
_areAllFullyLoaded: function() {
var tiledImage;
var count = this.world.getItemCount();