Add support for displaying images

3 files changed, 193 insertions, 5 deletions

diff --git a/ext/mixed/js/display-generator.js b/ext/mixed/js/display-generator.js
index 0f991362..a2b2b139 100644
--- a/ext/mixed/js/display-generator.js
+++ b/ext/mixed/js/display-generator.js
@@ -22,7 +22,8 @@
  */
 
 class DisplayGenerator {
-    constructor() {
+    constructor({mediaLoader}) {
+        this._mediaLoader = mediaLoader;
         this._templateHandler = null;
         this._termPitchAccentStaticTemplateIsSetup = false;
     }
@@ -176,16 +177,30 @@ class DisplayGenerator {
         const onlyListContainer = node.querySelector('.term-definition-disambiguation-list');
         const glossaryContainer = node.querySelector('.term-glossary-list');
 
-        node.dataset.dictionary = details.dictionary;
+        const dictionary = details.dictionary;
+        node.dataset.dictionary = dictionary;
 
         this._appendMultiple(tagListContainer, this._createTag.bind(this), details.definitionTags);
         this._appendMultiple(onlyListContainer, this._createTermDisambiguation.bind(this), details.only);
-        this._appendMultiple(glossaryContainer, this._createTermGlossaryItem.bind(this), details.glossary);
+        this._appendMultiple(glossaryContainer, this._createTermGlossaryItem.bind(this), details.glossary, dictionary);
 
         return node;
     }
 
-    _createTermGlossaryItem(glossary) {
+    _createTermGlossaryItem(glossary, dictionary) {
+        if (typeof glossary === 'string') {
+            return this._createTermGlossaryItemText(glossary);
+        } else if (typeof glossary === 'object' && glossary !== null) {
+            switch (glossary.type) {
+                case 'image':
+                    return this._createTermGlossaryItemImage(glossary, dictionary);
+            }
+        }
+
+        return null;
+    }
+
+    _createTermGlossaryItemText(glossary) {
         const node = this._templateHandler.instantiate('term-glossary-item');
         const container = node.querySelector('.term-glossary');
         if (container !== null) {
@@ -194,6 +209,68 @@ class DisplayGenerator {
         return node;
     }
 
+    _createTermGlossaryItemImage(data, dictionary) {
+        const {path, width, height, preferredWidth, preferredHeight, title, description, pixelated} = data;
+
+        const usedWidth = (
+            typeof preferredWidth === 'number' ?
+            preferredWidth :
+            width
+        );
+        const aspectRatio = (
+            typeof preferredWidth === 'number' &&
+            typeof preferredHeight === 'number' ?
+            preferredWidth / preferredHeight :
+            width / height
+        );
+
+        const node = this._templateHandler.instantiate('term-glossary-item-image');
+        node.dataset.path = path;
+        node.dataset.dictionary = dictionary;
+        node.dataset.imageLoadState = 'not-loaded';
+
+        const imageContainer = node.querySelector('.term-glossary-image-container');
+        imageContainer.style.width = `${usedWidth}em`;
+        if (typeof title === 'string') {
+            imageContainer.title = title;
+        }
+
+        const aspectRatioSizer = node.querySelector('.term-glossary-image-aspect-ratio-sizer');
+        aspectRatioSizer.style.paddingTop = `${aspectRatio * 100.0}%`;
+
+        const image = node.querySelector('img.term-glossary-image');
+        const imageLink = node.querySelector('.term-glossary-image-link');
+        image.dataset.pixelated = `${pixelated === true}`;
+
+        if (this._mediaLoader !== null) {
+            this._mediaLoader.loadMedia(
+                path,
+                dictionary,
+                (url) => this._setImageData(node, image, imageLink, url, false),
+                () => this._setImageData(node, image, imageLink, null, true)
+            );
+        }
+
+        if (typeof description === 'string') {
+            const container = node.querySelector('.term-glossary-image-description');
+            this._appendMultilineText(container, description);
+        }
+
+        return node;
+    }
+
+    _setImageData(container, image, imageLink, url, unloaded) {
+        if (url !== null) {
+            image.src = url;
+            imageLink.href = url;
+            container.dataset.imageLoadState = 'loaded';
+        } else {
+            image.removeAttribute('src');
+            imageLink.removeAttribute('href');
+            container.dataset.imageLoadState = unloaded ? 'unloaded' : 'load-error';
+        }
+    }
+
     _createTermDisambiguation(disambiguation) {
         const node = this._templateHandler.instantiate('term-definition-disambiguation');
         node.dataset.term = disambiguation;
diff --git a/ext/mixed/js/display.js b/ext/mixed/js/display.js
index c2284ffe..9587ec3b 100644
--- a/ext/mixed/js/display.js
+++ b/ext/mixed/js/display.js
@@ -20,6 +20,7 @@
  * DOM
  * DisplayContext
  * DisplayGenerator
+ * MediaLoader
  * WindowScroll
  * apiAudioGetUri
  * apiBroadcastTab
@@ -62,7 +63,8 @@ class Display {
         this.clickScanPrevent = false;
         this.setContentToken = null;
 
-        this.displayGenerator = new DisplayGenerator();
+        this.mediaLoader = new MediaLoader();
+        this.displayGenerator = new DisplayGenerator({mediaLoader: this.mediaLoader});
         this.windowScroll = new WindowScroll();
 
         this._onKeyDownHandlers = new Map([
@@ -479,6 +481,8 @@ class Display {
         const token = {}; // Unique identifier token
         this.setContentToken = token;
         try {
+            this.mediaLoader.unloadAll();
+
             switch (type) {
                 case 'terms':
                     await this.setContentTerms(details.definitions, details.context, token);
diff --git a/ext/mixed/js/media-loader.js b/ext/mixed/js/media-loader.js
new file mode 100644
index 00000000..c89c4f12
--- /dev/null
+++ b/ext/mixed/js/media-loader.js
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2020  Yomichan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/* global
+ * apiGetMedia
+ */
+
+class MediaLoader {
+    constructor() {
+        this._token = {};
+        this._mediaCache = new Map();
+        this._loadMediaData = [];
+    }
+
+    async loadMedia(path, dictionaryName, onLoad, onUnload) {
+        const token = this.token;
+        const data = {onUnload, loaded: false};
+
+        this._loadMediaData.push(data);
+
+        const media = await this.getMedia(path, dictionaryName);
+        if (token !== this.token) { return; }
+
+        onLoad(media.url);
+        data.loaded = true;
+    }
+
+    unloadAll() {
+        for (const {onUnload, loaded} of this._loadMediaData) {
+            if (typeof onUnload === 'function') {
+                onUnload(loaded);
+            }
+        }
+        this._loadMediaData = [];
+
+        for (const map of this._mediaCache.values()) {
+            for (const {url} of map.values()) {
+                if (url !== null) {
+                    URL.revokeObjectURL(url);
+                }
+            }
+        }
+        this._mediaCache.clear();
+
+        this._token = {};
+    }
+
+    async getMedia(path, dictionaryName) {
+        let cachedData;
+        let dictionaryCache = this._mediaCache.get(dictionaryName);
+        if (typeof dictionaryCache !== 'undefined') {
+            cachedData = dictionaryCache.get(path);
+        } else {
+            dictionaryCache = new Map();
+            this._mediaCache.set(dictionaryName, dictionaryCache);
+        }
+
+        if (typeof cachedData === 'undefined') {
+            cachedData = {
+                promise: null,
+                data: null,
+                url: null
+            };
+            dictionaryCache.set(path, cachedData);
+            cachedData.promise = this._getMediaData(path, dictionaryName, cachedData);
+        }
+
+        return cachedData.promise;
+    }
+
+    async _getMediaData(path, dictionaryName, cachedData) {
+        const token = this._token;
+        const data = (await apiGetMedia([{path, dictionaryName}]))[0];
+        if (token === this._token && data !== null) {
+            const sourceArrayBuffer = this._base64ToArrayBuffer(data.source);
+            const blob = new Blob([sourceArrayBuffer], {type: data.mediaType});
+            const url = URL.createObjectURL(blob);
+            cachedData.data = data;
+            cachedData.url = url;
+        }
+        return cachedData;
+    }
+
+    _base64ToArrayBuffer(source) {
+        const binarySource = window.atob(source);
+        const length = binarySource.length;
+        const array = new Uint8Array(length);
+        for (let i = 0; i < length; ++i) {
+            array[i] = binarySource.charCodeAt(i);
+        }
+        return array.buffer;
+    }
+}