move Display context to a new class

ext/bg/js/search.js

@@ -220,6 +220,7 @@ class DisplaySearch extends Display {
                 const {definitions} = await apiTermsFind(query, details, this.optionsContext);
                 this.setContentTerms(definitions, {
                     focus: false,
+                    disableHistory: true,
                     sentence: {text: query, offset: 0},
                     url: window.location.href
                 });

ext/bg/search.html

@@ -71,6 +71,7 @@
         <script src="/fg/js/source.js"></script>
         <script src="/fg/js/util.js"></script>
         <script src="/mixed/js/audio.js"></script>
+        <script src="/mixed/js/display-context.js"></script>
         <script src="/mixed/js/display.js"></script>
         <script src="/mixed/js/japanese.js"></script>
         <script src="/mixed/js/scroll.js"></script>

ext/fg/float.html

@@ -39,6 +39,7 @@
         <script src="/fg/js/document.js"></script>
         <script src="/fg/js/source.js"></script>
         <script src="/mixed/js/audio.js"></script>
+        <script src="/mixed/js/display-context.js"></script>
         <script src="/mixed/js/display.js"></script>
         <script src="/mixed/js/scroll.js"></script>
 

ext/mixed/js/display-context.js

@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) 2019  Alex Yatskov <alex@foosoft.net>
+ * Author: Alex Yatskov <alex@foosoft.net>
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+
+class DisplayContext {
+    constructor(type, definitions, context) {
+        this.type = type;
+        this.definitions = definitions;
+        this.context = context;
+    }
+
+    get(key) {
+        return this.context[key];
+    }
+
+    set(key, value) {
+        this.context[key] = value;
+    }
+
+    update(data) {
+        Object.assign(this.context, data);
+    }
+
+    get previous() {
+        return this.context.previous;
+    }
+
+    get next() {
+        return this.context.next;
+    }
+
+    static push(self, type, definitions, context) {
+        const newContext = new DisplayContext(type, definitions, context);
+        if (self !== null) {
+            newContext.update({previous: self});
+            self.update({next: newContext});
+        }
+        return newContext;
+    }
+}

ext/mixed/js/display.js

@@ -64,27 +64,17 @@ class Display {
         try {
             e.preventDefault();
             if (!this.context) { return; }
-            this.context.details.context.next = null;
 
             const link = e.target;
-            const {type, details} = this.context;
+            this.context.update({
-            const context = {
-                source: {
-                    type,
-                    details: {
-                        definitions: this.definitions,
-                        context: Object.assign({}, details.context, {
                 index: this.entryIndexFind(link),
                 scroll: this.windowScroll.y
-                        })
+            });
-                    }
+            const context = {
-                },
+                sentence: this.context.get('sentence'),
-                sentence: details.context.sentence,
+                url: this.context.get('url')
-                url: details.context.url
             };
 
-            this.windowScroll.toY(0);
-
             const definitions = await apiKanjiFind(link.textContent, this.getOptionsContext());
             this.setContentKanji(definitions, context);
         } catch (error) {
@@ -111,7 +101,7 @@ class Display {
     async onTermLookup(e, {disableScroll, selectText, disableHistory}={}) {
         try {
             if (!this.context) { return; }
-            this.context.details.context.next = null;
+
             const termLookupResults = await this.termLookup(e);
             if (!termLookupResults) { return; }
             const {textSource, definitions} = termLookupResults;
@@ -119,29 +109,29 @@ class Display {
             const scannedElement = e.target;
             const sentence = docSentenceExtract(textSource, this.options.anki.sentenceExt);
 
-            const {type, details} = this.context;
             const context = {
-                source: disableHistory ? details.context.source : {
+                disableScroll,
-                    type,
+                disableHistory,
-                    details: {
+                sentence,
-                        definitions: this.definitions,
+                url: this.context.get('url')
-                        context: Object.assign({}, details.context, {
+            };
+            if (disableHistory) {
+                Object.assign(context, {
+                    previous: this.context.previous,
+                    next: this.context.next
+                });
+            } else {
+                this.context.update({
                     index: this.entryIndexFind(scannedElement),
                     scroll: this.windowScroll.y
-                        })
+                });
+                Object.assign(context, {
+                    previous: this.context
+                });
             }
-                },
-                disableScroll,
-                sentence,
-                url: details.context.url
-            };
 
             this.setContentTerms(definitions, context);
 
-            if (!disableScroll) {
-                this.windowScroll.toY(0);
-            }
-
             if (selectText) {
                 textSource.select();
             }
@@ -354,16 +344,18 @@ class Display {
             }
 
             this.definitions = definitions;
-            this.context = {
+            if (context.disableHistory) {
-                type: 'terms',
+                delete context.disableHistory;
-                details: {definitions, context}
+                this.context = new DisplayContext('terms', definitions, context);
-            };
+            } else {
+                this.context = DisplayContext.push(this.context, 'terms', definitions, context);
+            }
 
             const sequence = ++this.sequence;
             const params = {
                 definitions,
-                source: context.source,
+                source: this.context.previous,
-                next: context.next,
+                next: this.context.next,
                 addable: options.anki.enable,
                 grouped: options.general.resultOutputMode === 'group',
                 merged: options.general.resultOutputMode === 'merge',
@@ -383,6 +375,7 @@ class Display {
             if (!disableScroll) {
                 this.entryScrollIntoView(index || 0, scroll);
             } else {
+                delete context.disableScroll;
                 this.entrySetCurrent(index || 0);
             }
 
@@ -412,16 +405,18 @@ class Display {
             }
 
             this.definitions = definitions;
-            this.context = {
+            if (context.disableHistory) {
-                type: 'kanji',
+                delete context.disableHistory;
-                details: {definitions, context}
+                this.context = new DisplayContext('kanji', definitions, context);
-            };
+            } else {
+                this.context = DisplayContext.push(this.context, 'kanji', definitions, context);
+            }
 
             const sequence = ++this.sequence;
             const params = {
                 definitions,
-                source: context.source,
+                source: this.context.previous,
-                next: context.next,
+                next: this.context.next,
                 addable: options.anki.enable,
                 debug: options.general.debugInfo
             };
@@ -531,28 +526,33 @@ class Display {
     }
 
     sourceTermView() {
-        if (!this.context || !this.context.details.context.source) { return; }
+        if (!this.context || !this.context.previous) { return; }
-        const {type, details} = this.context;
+        this.context.update({
-        const sourceContext = details.context.source;
-        sourceContext.details.context.next = {
-            type,
-            details: {
-                definitions: this.definitions,
-                context: Object.assign({}, details.context, {
             index: this.index,
             scroll: this.windowScroll.y
-                })
+        });
-            }
+        const previousContext = this.context.previous;
+        previousContext.set('disableHistory', true);
+        const details = {
+            definitions: previousContext.definitions,
+            context: previousContext.context
         };
-        this.setContent(sourceContext.type, sourceContext.details);
+        this.setContent(previousContext.type, details);
     }
 
     nextTermView() {
-        if (!this.context.details.context.next) { return; }
+        if (!this.context || !this.context.next) { return; }
-        this.context.details.context.index = this.index;
+        this.context.update({
-        this.context.details.context.scroll = this.windowScroll.y;
+            index: this.index,
-        const {type, details} = this.context.details.context.next;
+            scroll: this.windowScroll.y
-        this.setContent(type, details);
+        });
+        const nextContext = this.context.next;
+        nextContext.set('disableHistory', true);
+        const details = {
+            definitions: nextContext.definitions,
+            context: nextContext.context
+        };
+        this.setContent(nextContext.type, details);
     }
 
     noteTryAdd(mode) {