Move structured-content generation code into a separate file (#1757)

1 files changed, 213 insertions, 0 deletions

diff --git a/ext/js/display/structured-content-generator.js b/ext/js/display/structured-content-generator.js
new file mode 100644
index 00000000..cd4ea091
--- /dev/null
+++ b/ext/js/display/structured-content-generator.js
@@ -0,0 +1,213 @@
+/*
+ * Copyright (C) 2021  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/>.
+ */
+
+class StructuredContentGenerator {
+    constructor(templates, mediaLoader, document) {
+        this._templates = templates;
+        this._mediaLoader = mediaLoader;
+        this._document = document;
+    }
+
+    createStructuredContent(content, dictionary) {
+        if (typeof content === 'string') {
+            return this._createTextNode(content);
+        }
+        if (!(typeof content === 'object' && content !== null)) {
+            return null;
+        }
+        if (Array.isArray(content)) {
+            const fragment = this._createDocumentFragment();
+            for (const item of content) {
+                const child = this.createStructuredContent(item, dictionary);
+                if (child !== null) { fragment.appendChild(child); }
+            }
+            return fragment;
+        }
+        const {tag} = content;
+        switch (tag) {
+            case 'br':
+                return this._createStructuredContentElement(tag, content, dictionary, 'simple', false, false);
+            case 'ruby':
+            case 'rt':
+            case 'rp':
+                return this._createStructuredContentElement(tag, content, dictionary, 'simple', true, false);
+            case 'table':
+                return this._createStructuredContentTableElement(tag, content, dictionary);
+            case 'thead':
+            case 'tbody':
+            case 'tfoot':
+            case 'tr':
+                return this._createStructuredContentElement(tag, content, dictionary, 'table', true, false);
+            case 'th':
+            case 'td':
+                return this._createStructuredContentElement(tag, content, dictionary, 'table-cell', true, true);
+            case 'div':
+            case 'span':
+                return this._createStructuredContentElement(tag, content, dictionary, 'simple', true, true);
+            case 'img':
+                return this.createDefinitionImage(content, dictionary);
+        }
+        return null;
+    }
+
+    createDefinitionImage(data, dictionary) {
+        const {
+            path,
+            width,
+            height,
+            preferredWidth,
+            preferredHeight,
+            title,
+            pixelated,
+            imageRendering,
+            appearance,
+            background,
+            collapsed,
+            collapsible,
+            verticalAlign,
+            sizeUnits
+        } = data;
+
+        const hasPreferredWidth = (typeof preferredWidth === 'number');
+        const hasPreferredHeight = (typeof preferredHeight === 'number');
+        const aspectRatio = (
+            hasPreferredWidth && hasPreferredHeight ?
+            preferredWidth / preferredHeight :
+            width / height
+        );
+        const usedWidth = (
+            hasPreferredWidth ?
+            preferredWidth :
+            (hasPreferredHeight ? preferredHeight * aspectRatio : width)
+        );
+
+        const node = this._templates.instantiate('gloss-item-image');
+        const imageContainer = node.querySelector('.gloss-image-container');
+        const aspectRatioSizer = node.querySelector('.gloss-image-aspect-ratio-sizer');
+        const image = node.querySelector('.gloss-image');
+        const imageBackground = node.querySelector('.gloss-image-background');
+
+        node.dataset.path = path;
+        node.dataset.dictionary = dictionary;
+        node.dataset.imageLoadState = 'not-loaded';
+        node.dataset.hasAspectRatio = 'true';
+        node.dataset.imageRendering = typeof imageRendering === 'string' ? imageRendering : (pixelated ? 'pixelated' : 'auto');
+        node.dataset.appearance = typeof appearance === 'string' ? appearance : 'auto';
+        node.dataset.background = typeof background === 'boolean' ? `${background}` : 'true';
+        node.dataset.collapsed = typeof collapsed === 'boolean' ? `${collapsed}` : 'false';
+        node.dataset.collapsible = typeof collapsible === 'boolean' ? `${collapsible}` : 'true';
+        if (typeof verticalAlign === 'string') {
+            node.dataset.verticalAlign = verticalAlign;
+        }
+        if (typeof sizeUnits === 'string' && (hasPreferredWidth || hasPreferredHeight)) {
+            node.dataset.sizeUnits = sizeUnits;
+        }
+
+        imageContainer.style.width = `${usedWidth}em`;
+        if (typeof title === 'string') {
+            imageContainer.title = title;
+        }
+
+        aspectRatioSizer.style.paddingTop = `${aspectRatio * 100.0}%`;
+
+        if (this._mediaLoader !== null) {
+            this._mediaLoader.loadMedia(
+                path,
+                dictionary,
+                (url) => this._setImageData(node, image, imageBackground, url, false),
+                () => this._setImageData(node, image, imageBackground, null, true)
+            );
+        }
+
+        return node;
+    }
+
+    // Private
+
+    _createElement(tagName) {
+        return this._document.createElement(tagName);
+    }
+
+    _createTextNode(data) {
+        return this._document.createTextNode(data);
+    }
+
+    _createDocumentFragment() {
+        return this._document.createDocumentFragment();
+    }
+
+    _setImageData(node, image, imageBackground, url, unloaded) {
+        if (url !== null) {
+            image.src = url;
+            node.href = url;
+            node.dataset.imageLoadState = 'loaded';
+            imageBackground.style.setProperty('--image', `url("${url}")`);
+        } else {
+            image.removeAttribute('src');
+            node.removeAttribute('href');
+            node.dataset.imageLoadState = unloaded ? 'unloaded' : 'load-error';
+            imageBackground.style.removeProperty('--image');
+        }
+    }
+
+    _createStructuredContentTableElement(tag, content, dictionary) {
+        const container = this._createElement('div');
+        container.classList = 'gloss-sc-table-container';
+        const table = this._createStructuredContentElement(tag, content, dictionary, 'table', true, false);
+        container.appendChild(table);
+        return container;
+    }
+
+    _createStructuredContentElement(tag, content, dictionary, type, hasChildren, hasStyle) {
+        const node = this._createElement(tag);
+        node.className = `gloss-sc-${tag}`;
+        switch (type) {
+            case 'table-cell':
+                {
+                    const {colSpan, rowSpan} = content;
+                    if (typeof colSpan === 'number') { node.colSpan = colSpan; }
+                    if (typeof rowSpan === 'number') { node.rowSpan = rowSpan; }
+                }
+                break;
+        }
+        if (hasStyle) {
+            const {style} = content;
+            if (typeof style === 'object' && style !== null) {
+                this._setStructuredContentElementStyle(node, style);
+            }
+        }
+        if (hasChildren) {
+            const child = this.createStructuredContent(content.content, dictionary);
+            if (child !== null) { node.appendChild(child); }
+        }
+        return node;
+    }
+
+    _setStructuredContentElementStyle(node, contentStyle) {
+        const {style} = node;
+        const {fontStyle, fontWeight, fontSize, textDecorationLine, verticalAlign} = contentStyle;
+        if (typeof fontStyle === 'string') { style.fontStyle = fontStyle; }
+        if (typeof fontWeight === 'string') { style.fontWeight = fontWeight; }
+        if (typeof fontSize === 'string') { style.fontSize = fontSize; }
+        if (typeof verticalAlign === 'string') { style.verticalAlign = verticalAlign; }
+        if (typeof textDecorationLine === 'string') {
+            style.textDecoration = textDecorationLine;
+        } else if (Array.isArray(textDecorationLine)) {
+            style.textDecoration = textDecorationLine.join(' ');
+        }
+    }
+}