Delete cache image when image annotation position changes

chrome/content/zotero/xpcom/annotations.js

@@ -57,6 +57,7 @@ Zotero.Annotations = new function () {
 		await Zotero.File.createDirectoryIfMissingAsync(file, { from: cacheDir });
 		
 		file = OS.Path.join(file, item.key + '.png');
+		Zotero.debug("Creating annotation cache file " + file);
 		await Zotero.File.putContentsAsync(file, blob);
 		await Zotero.File.setNormalFilePermissions(file);
 		
@@ -66,6 +67,7 @@ Zotero.Annotations = new function () {
 	
 	this.removeCacheImage = async function ({ libraryID, key }) {
 		var path = this.getCacheImagePath({ libraryID, key });
+		Zotero.debug("Deleting annotation cache file " + path);
 		await OS.File.remove(path, { ignoreAbsent: true });
 	};
 	
@@ -103,12 +105,6 @@ Zotero.Annotations = new function () {
 	};
 	
 	
-	this.positionEquals = function (position1, position2) {
-		return position1.pageIndex == position2.pageIndex
-			&& JSON.stringify(position1.rects) == JSON.stringify(position2.rects);
-	};
-	
-	
 	this.toJSON = async function (item) {
 		var o = {};
 		o.libraryID = item.libraryID;
@@ -203,13 +199,6 @@ Zotero.Annotations = new function () {
 		item.annotationPageLabel = json.pageLabel;
 		item.annotationSortIndex = json.sortIndex;
 		
-		if (item.annotationType == 'image' && item.annotationPosition) {
-			var currentPosition = JSON.parse(item.annotationPosition);
-			if (!this.positionEquals(currentPosition, json.position)) {
-				await this.removeCacheImage(item);
-			}
-		}
-
 		item.annotationPosition = JSON.stringify(Object.assign({}, json.position));
 		// TODO: Can colors be set?
 		item.setTags((json.tags || []).map(t => ({ tag: t.name })));

chrome/content/zotero/xpcom/data/item.js

@@ -1833,6 +1833,15 @@ Zotero.Item.prototype._saveData = Zotero.Promise.coroutine(function* (env) {
 		
 		// Clear cached child items of the parent attachment
 		reloadParentChildItems[parentItemID] = true;
+		
+		// Mark cache image for deletion when image annotation position changes
+		if (!isNew && type == 'image' && this._hasFieldChanged('annotationPosition')) {
+			let libraryID = this.libraryID;
+			let key = this.key;
+			Zotero.DB.addCurrentCallback("commit", function () {
+				Zotero.Annotations.removeCacheImage({ libraryID, key });
+			}.bind(this));
+		}
 	}
 	
 	// Add to new collections

test/tests/itemTest.js

@@ -1304,6 +1304,29 @@ describe("Zotero.Item", function () {
 					imageData
 				);
 			});
+			
+			it("should remove cached image for an annotation item when position changes", async function () {
+				var attachment = await importFileAttachment('test.pdf');
+				var annotation = await createAnnotation('image', attachment);
+				
+				// Get Blob from file and attach it
+				var path = OS.Path.join(getTestDataDirectory().path, 'test.png');
+				var imageData = await Zotero.File.getBinaryContentsAsync(path);
+				var array = new Uint8Array(imageData.length);
+				for (let i = 0; i < imageData.length; i++) {
+					array[i] = imageData.charCodeAt(i);
+				}
+				var blob = new Blob([array], { type: 'image/png' });
+				var file = await Zotero.Annotations.saveCacheImage(annotation, blob);
+				
+				assert.isTrue(await OS.File.exists(file));
+				
+				var position = JSON.parse(annotation.annotationPosition);
+				position.rects[0][0] = position.rects[0][0] + 1;
+				annotation.annotationPosition = JSON.stringify(position);
+				await annotation.saveTx();
+				assert.isFalse(await OS.File.exists(file));
+			});
 		});
 		
 		describe("#getAnnotations()", function () {