From ad17b0603bfcbb6be54fd4941b6a7ca4195947fc Mon Sep 17 00:00:00 2001
From: Alex Yatskov <alex@foosoft.net>
Date: Sat, 18 Mar 2017 17:40:48 -0700
Subject: [PATCH] scrolling

---
 ext/fg/frame.html       |  3 ++-
 ext/mixed/css/frame.css |  5 ++++
 ext/mixed/js/display.js | 53 ++++++++++++++++++++++++++++++++++-------
 3 files changed, 52 insertions(+), 9 deletions(-)

diff --git a/ext/fg/frame.html b/ext/fg/frame.html
index d915281c..c593db8d 100644
--- a/ext/fg/frame.html
+++ b/ext/fg/frame.html
@@ -8,7 +8,8 @@
         <link rel="stylesheet" href="/mixed/css/frame.css">
         <style type="text/css">
             .entry {
-                padding: 10px;
+                padding-left: 10px;
+                padding-right: 10px;
             }
         </style>
     </head>
diff --git a/ext/mixed/css/frame.css b/ext/mixed/css/frame.css
index 78108dd5..a425aca8 100644
--- a/ext/mixed/css/frame.css
+++ b/ext/mixed/css/frame.css
@@ -51,6 +51,11 @@ hr {
  * Entries
  */
 
+.entry {
+    padding-top: 10px;
+    padding-bottom: 10px;
+}
+
 .tag-default {
     background-color: #8a8a91;
 }
diff --git a/ext/mixed/js/display.js b/ext/mixed/js/display.js
index d90cf897..11df7208 100644
--- a/ext/mixed/js/display.js
+++ b/ext/mixed/js/display.js
@@ -24,6 +24,9 @@ class Display {
         this.definitions = [];
         this.audioCache = {};
         this.sequence = 0;
+        this.index = 0;
+
+        $(document).keydown(this.onKeyDown.bind(this));
     }
 
     definitionAdd(definition, mode) {
@@ -47,6 +50,8 @@ class Display {
     }
 
     showTermDefs(definitions, options, context) {
+        window.focus();
+
         this.spinner.hide();
         this.definitions = definitions;
 
@@ -68,13 +73,8 @@ class Display {
         this.templateRender('terms.html', params).then(content => {
             this.container.html(content);
 
-            let offset = 0;
-            if (context && context.hasOwnProperty('index') && context.index < definitions.length) {
-                const entry = $('.entry').eq(context.index);
-                offset = entry.offset().top;
-            }
-
-            window.scrollTo(0, offset);
+            const index = context && context.hasOwnProperty('index') ? context.index : 0;
+            this.entryScroll(index);
 
             $('.action-add-note').click(this.onActionAddNote.bind(this));
             $('.action-play-audio').click(e => {
@@ -102,6 +102,8 @@ class Display {
     }
 
     showKanjiDefs(definitions, options, context) {
+        window.focus();
+
         this.spinner.hide();
         this.definitions = definitions;
 
@@ -121,7 +123,9 @@ class Display {
 
         this.templateRender('kanji.html', params).then(content => {
             this.container.html(content);
-            window.scrollTo(0, 0);
+
+            const index = context && context.hasOwnProperty('index') ? context.index : 0;
+            this.entryScroll(index);
 
             $('.action-add-note').click(this.onActionAddNote.bind(this));
             $('.source-term').click(e => {
@@ -158,6 +162,23 @@ class Display {
         });
     }
 
+    entryScroll(index, smooth) {
+        if (index < 0 || index >= this.definitions.length) {
+            return;
+        }
+
+        const body = $('body').stop();
+        const entry = $('.entry').eq(index);
+
+        if (smooth) {
+            body.animate({scrollTop: entry.offset().top}, 200);
+        } else {
+            body.scrollTop(entry.offset().top);
+        }
+
+        this.index = index;
+    }
+
     onActionAddNote(e) {
         e.preventDefault();
         this.spinner.show();
@@ -184,6 +205,22 @@ class Display {
         }).catch(this.handleError.bind(this)).then(() => this.spinner.hide());
     }
 
+    onKeyDown(e) {
+        if (e.keyCode === 36 /* home */) {
+            e.preventDefault();
+            this.entryScroll(0, true);
+        } else if (e.keyCode === 35 /* end */) {
+            e.preventDefault();
+            this.entryScroll(this.definitions.length - 1, true);
+        } if (e.keyCode === 38 /* up */) {
+            e.preventDefault();
+            this.entryScroll(this.index - 1, true);
+        } else if (e.keyCode === 40 /* down */) {
+            e.preventDefault();
+            this.entryScroll(this.index + 1, true);
+        }
+    }
+
     static audioPlay(definition, cache) {
         for (const key in cache) {
             const audio = cache[key];