From d640a8ee221c26ad4612595157e6cbe9f0fd5709 Mon Sep 17 00:00:00 2001
From: Jasper van Merle <jaspervmerle@gmail.com>
Date: Mon, 28 Jan 2019 17:51:28 +0100
Subject: [PATCH 1/3] Set favicon to documentation icon on open

---
 .../javascripts/views/sidebar/doc_list.coffee | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/assets/javascripts/views/sidebar/doc_list.coffee b/assets/javascripts/views/sidebar/doc_list.coffee
index c72877a8..d24c2476 100644
--- a/assets/javascripts/views/sidebar/doc_list.coffee
+++ b/assets/javascripts/views/sidebar/doc_list.coffee
@@ -94,6 +94,8 @@ class app.views.DocList extends app.View
     $.stopEvent(event)
     doc = app.docs.findBy 'slug', event.target.getAttribute('data-slug')
 
+    @setFaviconForDoc(doc)
+
     if doc and not @lists[doc.slug]
       @lists[doc.slug] = if doc.types.isEmpty()
         new app.views.EntryList doc.entries.all()
@@ -111,6 +113,29 @@ class app.views.DocList extends app.View
       delete @lists[doc.slug]
     return
 
+  setFaviconForDoc: (doc) ->
+    link = $("a._list-item[data-slug='#{doc.slug}']")
+    styles = window.getComputedStyle(link, ':before')
+
+    bgUrl = styles['background-image'].slice(5, -2)
+    bgSize = if bgUrl.includes('@2x') then 32 else 16
+    bgPositions = styles['background-position'].split(' ')
+    bgX = parseInt(bgPositions[0].slice(0, -2))
+    bgY = parseInt(bgPositions[1].slice(0, -2))
+
+    img = new Image()
+    img.src = bgUrl
+    img.onload = () =>
+      canvas = document.createElement('canvas')
+
+      canvas.width = bgSize
+      canvas.height = bgSize
+      canvas.getContext('2d').drawImage(img, bgX, bgY)
+
+      $('link[rel="icon"]').href = canvas.toDataURL()
+      return
+    return
+
   select: (model) ->
     @listSelect.selectByHref model?.fullPath()
     return

From c36478ce8265e480e4a0e759d1836ffdb07ced76 Mon Sep 17 00:00:00 2001
From: Jasper van Merle <jaspervmerle@gmail.com>
Date: Fri, 1 Feb 2019 09:30:19 +0100
Subject: [PATCH 2/3] Set favicon to the icon of the currently shown docs

---
 assets/javascripts/lib/favicon.coffee         | 53 +++++++++++++++++++
 .../javascripts/views/content/content.coffee  |  3 ++
 .../views/content/entry_page.coffee           |  1 +
 .../views/content/type_page.coffee            |  1 +
 .../javascripts/views/sidebar/doc_list.coffee | 25 ---------
 5 files changed, 58 insertions(+), 25 deletions(-)
 create mode 100644 assets/javascripts/lib/favicon.coffee

diff --git a/assets/javascripts/lib/favicon.coffee b/assets/javascripts/lib/favicon.coffee
new file mode 100644
index 00000000..aa319e27
--- /dev/null
+++ b/assets/javascripts/lib/favicon.coffee
@@ -0,0 +1,53 @@
+defaultUrl = null
+currentSlug = null
+
+imageCache = {}
+urlCache = {}
+
+withImage = (url, action) ->
+  if imageCache[url]
+    action(imageCache[url])
+  else
+    img = new Image()
+    img.src = url
+    img.onload = () =>
+      imageCache[url] = img
+      action(img)
+
+@setFaviconForDoc = (doc) ->
+  return if currentSlug == doc.slug
+
+  favicon = $('link[rel="icon"]')
+
+  if urlCache[doc.slug]
+    favicon.href = urlCache[doc.slug]
+    currentSlug = doc.slug
+    return
+
+  styles = window.getComputedStyle($("._icon-#{doc.slug}"), ':before')
+
+  bgUrl = styles['background-image'].slice(5, -2)
+  bgSize = if bgUrl.includes('@2x') then 32 else 16
+  bgX = parseInt(styles['background-position-x'].slice(0, -2))
+  bgY = parseInt(styles['background-position-y'].slice(0, -2))
+
+  withImage(bgUrl, (img) ->
+    canvas = document.createElement('canvas')
+
+    canvas.width = bgSize
+    canvas.height = bgSize
+    canvas.getContext('2d').drawImage(img, bgX, bgY)
+
+    if defaultUrl == null
+      defaultUrl = favicon.href
+
+    urlCache[doc.slug] = canvas.toDataURL()
+    favicon.href = urlCache[doc.slug]
+
+    currentSlug = doc.slug
+  )
+
+@resetFavicon = () ->
+  if defaultUrl != null and currentSlug != null
+    $('link[rel="icon"]').href = defaultUrl
+    currentSlug = null
diff --git a/assets/javascripts/views/content/content.coffee b/assets/javascripts/views/content/content.coffee
index 8c5ba874..4e01733e 100644
--- a/assets/javascripts/views/content/content.coffee
+++ b/assets/javascripts/views/content/content.coffee
@@ -153,6 +153,9 @@ class app.views.Content extends app.View
     return
 
   afterRoute: (route, context) =>
+    if route != 'entry' and route != 'type'
+      resetFavicon()
+
     switch route
       when 'root'
         @show @rootPage
diff --git a/assets/javascripts/views/content/entry_page.coffee b/assets/javascripts/views/content/entry_page.coffee
index beae4d77..00762fa6 100644
--- a/assets/javascripts/views/content/entry_page.coffee
+++ b/assets/javascripts/views/content/entry_page.coffee
@@ -40,6 +40,7 @@ class app.views.EntryPage extends app.View
     if app.disabledDocs.findBy 'slug', @entry.doc.slug
       @hiddenView = new app.views.HiddenPage @el, @entry
 
+    setFaviconForDoc(@entry.doc)
     @delay @polyfillMathML
     @trigger 'loaded'
     return
diff --git a/assets/javascripts/views/content/type_page.coffee b/assets/javascripts/views/content/type_page.coffee
index 147fa7ed..ef360c14 100644
--- a/assets/javascripts/views/content/type_page.coffee
+++ b/assets/javascripts/views/content/type_page.coffee
@@ -9,6 +9,7 @@ class app.views.TypePage extends app.View
 
   render: (@type) ->
     @html @tmpl('typePage', @type)
+    setFaviconForDoc(@type.doc)
     return
 
   getTitle: ->
diff --git a/assets/javascripts/views/sidebar/doc_list.coffee b/assets/javascripts/views/sidebar/doc_list.coffee
index d24c2476..c72877a8 100644
--- a/assets/javascripts/views/sidebar/doc_list.coffee
+++ b/assets/javascripts/views/sidebar/doc_list.coffee
@@ -94,8 +94,6 @@ class app.views.DocList extends app.View
     $.stopEvent(event)
     doc = app.docs.findBy 'slug', event.target.getAttribute('data-slug')
 
-    @setFaviconForDoc(doc)
-
     if doc and not @lists[doc.slug]
       @lists[doc.slug] = if doc.types.isEmpty()
         new app.views.EntryList doc.entries.all()
@@ -113,29 +111,6 @@ class app.views.DocList extends app.View
       delete @lists[doc.slug]
     return
 
-  setFaviconForDoc: (doc) ->
-    link = $("a._list-item[data-slug='#{doc.slug}']")
-    styles = window.getComputedStyle(link, ':before')
-
-    bgUrl = styles['background-image'].slice(5, -2)
-    bgSize = if bgUrl.includes('@2x') then 32 else 16
-    bgPositions = styles['background-position'].split(' ')
-    bgX = parseInt(bgPositions[0].slice(0, -2))
-    bgY = parseInt(bgPositions[1].slice(0, -2))
-
-    img = new Image()
-    img.src = bgUrl
-    img.onload = () =>
-      canvas = document.createElement('canvas')
-
-      canvas.width = bgSize
-      canvas.height = bgSize
-      canvas.getContext('2d').drawImage(img, bgX, bgY)
-
-      $('link[rel="icon"]').href = canvas.toDataURL()
-      return
-    return
-
   select: (model) ->
     @listSelect.selectByHref model?.fullPath()
     return

From 14e49f7014523a807d01df4b04ae470c3da6c2e9 Mon Sep 17 00:00:00 2001
From: Jasper van Merle <jaspervmerle@gmail.com>
Date: Sat, 16 Feb 2019 23:41:06 +0100
Subject: [PATCH 3/3] Use GitHub's parent-child style

---
 assets/javascripts/lib/favicon.coffee | 36 +++++++++++++++++----------
 1 file changed, 23 insertions(+), 13 deletions(-)

diff --git a/assets/javascripts/lib/favicon.coffee b/assets/javascripts/lib/favicon.coffee
index aa319e27..f42b1281 100644
--- a/assets/javascripts/lib/favicon.coffee
+++ b/assets/javascripts/lib/favicon.coffee
@@ -19,6 +19,9 @@ withImage = (url, action) ->
 
   favicon = $('link[rel="icon"]')
 
+  if defaultUrl == null
+    defaultUrl = favicon.href
+
   if urlCache[doc.slug]
     favicon.href = urlCache[doc.slug]
     currentSlug = doc.slug
@@ -27,24 +30,31 @@ withImage = (url, action) ->
   styles = window.getComputedStyle($("._icon-#{doc.slug}"), ':before')
 
   bgUrl = styles['background-image'].slice(5, -2)
-  bgSize = if bgUrl.includes('@2x') then 32 else 16
-  bgX = parseInt(styles['background-position-x'].slice(0, -2))
-  bgY = parseInt(styles['background-position-y'].slice(0, -2))
+  sourceSize = if bgUrl.includes('@2x') then 32 else 16
+  sourceX = Math.abs(parseInt(styles['background-position-x'].slice(0, -2)))
+  sourceY = Math.abs(parseInt(styles['background-position-y'].slice(0, -2)))
 
-  withImage(bgUrl, (img) ->
-    canvas = document.createElement('canvas')
+  withImage(bgUrl, (docImg) ->
+    withImage(defaultUrl, (defaultImg) ->
+      size = defaultImg.width
 
-    canvas.width = bgSize
-    canvas.height = bgSize
-    canvas.getContext('2d').drawImage(img, bgX, bgY)
+      canvas = document.createElement('canvas')
+      ctx = canvas.getContext('2d')
 
-    if defaultUrl == null
-      defaultUrl = favicon.href
+      canvas.width = size
+      canvas.height = size
+      ctx.drawImage(defaultImg, 0, 0)
 
-    urlCache[doc.slug] = canvas.toDataURL()
-    favicon.href = urlCache[doc.slug]
+      docIconPercentage = 65
+      destinationCoords = size / 100 * (100 - docIconPercentage)
+      destinationSize = size / 100 * docIconPercentage
+      ctx.drawImage(docImg, sourceX, sourceY, sourceSize, sourceSize, destinationCoords, destinationCoords, destinationSize, destinationSize)
 
-    currentSlug = doc.slug
+      urlCache[doc.slug] = canvas.toDataURL()
+      favicon.href = urlCache[doc.slug]
+
+      currentSlug = doc.slug
+    )
   )
 
 @resetFavicon = () ->