Updated commit diff view with some minor visual modifications

Prepared diff view for multiple view modes

Converted commits.js to coffeescript
image info in separate coffeescript file

Added swipe view mode

Added onion skin viewMode

app/assets/javascripts/commit/file.js.coffee

@@ -0,0 +1,7 @@
+class CommitFile
+  
+  constructor: (file) ->
+    if $('.image', file).length
+      new ImageFile(file)
+        
+this.CommitFile = CommitFile

app/assets/javascripts/commit/image-file.js.coffee

@@ -0,0 +1,128 @@
+class ImageFile
+
+  # Width where images must fits in, for 2-up this gets divided by 2
+  @availWidth = 900
+  @viewModes = ['two-up', 'swipe']
+
+  constructor: (@file) ->
+    # Determine if old and new file has same dimensions, if not show 'two-up' view
+    this.requestImageInfo $('.two-up.view .frame.deleted img', @file), (deletedWidth, deletedHeight) =>
+      this.requestImageInfo $('.two-up.view .frame.added img', @file), (width, height) =>
+        if width == deletedWidth && height == deletedHeight
+          this.initViewModes()
+        else
+          this.initView('two-up')
+
+  initViewModes: ->
+    viewMode = ImageFile.viewModes[0]
+
+    $('.view-modes', @file).removeClass 'hide'
+    $('.view-modes-menu', @file).on 'click', 'li', (event) =>
+      unless $(event.currentTarget).hasClass('active')
+        this.activateViewMode(event.currentTarget.className)
+
+    this.activateViewMode(viewMode)
+
+  activateViewMode: (viewMode) ->
+    $('.view-modes-menu li', @file)
+      .removeClass('active')
+      .filter(".#{viewMode}").addClass 'active'
+    $(".view:visible:not(.#{viewMode})", @file).fadeOut 200, =>
+      $(".view.#{viewMode}", @file).fadeIn(200)
+      this.initView viewMode
+
+  initView: (viewMode) ->
+    this.views[viewMode].call(this)
+
+  prepareFrames = (view) ->
+    maxWidth = 0
+    maxHeight = 0
+    $('.frame', view).each (index, frame) =>
+      width = $(frame).width()
+      height = $(frame).height()
+      maxWidth = if width > maxWidth then width else maxWidth
+      maxHeight = if height > maxHeight then height else maxHeight
+    .css
+      width: maxWidth
+      height: maxHeight
+    
+    [maxWidth, maxHeight]
+
+  views: 
+    'two-up': ->
+      $('.two-up.view .wrap', @file).each (index, wrap) =>
+        $('img', wrap).each ->
+          currentWidth = $(this).width()
+          if currentWidth > ImageFile.availWidth / 2
+            $(this).width ImageFile.availWidth / 2
+
+        this.requestImageInfo $('img', wrap), (width, height) ->
+          $('.image-info .meta-width', wrap).text "#{width}px"
+          $('.image-info .meta-height', wrap).text "#{height}px"
+          $('.image-info', wrap).removeClass('hide')
+
+    'swipe': ->
+      maxWidth = 0
+      maxHeight = 0
+
+      $('.swipe.view', @file).each (index, view) =>
+
+        [maxWidth, maxHeight] = prepareFrames(view)
+
+        $('.swipe-frame', view).css
+          width: maxWidth + 16
+          height: maxHeight + 28
+
+        $('.swipe-wrap', view).css
+          width: maxWidth + 1
+          height: maxHeight + 2
+
+        $('.swipe-bar', view).css
+          left: 0
+        .draggable
+          axis: 'x'
+          containment: 'parent'
+          drag: (event) ->
+            $('.swipe-wrap', view).width (maxWidth + 1) - $(this).position().left
+          stop: (event) ->
+            $('.swipe-wrap', view).width (maxWidth + 1) - $(this).position().left
+
+    'onion-skin': ->
+      maxWidth = 0
+      maxHeight = 0
+
+      dragTrackWidth = $('.drag-track', @file).width() - $('.dragger', @file).width()
+
+      $('.onion-skin.view', @file).each (index, view) =>
+
+        [maxWidth, maxHeight] = prepareFrames(view)
+
+        $('.onion-skin-frame', view).css
+          width: maxWidth + 16
+          height: maxHeight + 28
+
+        $('.swipe-wrap', view).css
+          width: maxWidth + 1
+          height: maxHeight + 2
+        
+        $('.dragger', view).css
+          left: dragTrackWidth
+        .draggable
+          axis: 'x'
+          containment: 'parent'
+          drag: (event) ->
+            $('.frame.added', view).css('opacity', $(this).position().left / dragTrackWidth)
+          stop: (event) ->
+            $('.frame.added', view).css('opacity', $(this).position().left / dragTrackWidth)
+        
+      
+
+  requestImageInfo: (img, callback) ->
+    domImg = img.get(0)
+    if domImg.complete
+      callback.call(this, domImg.naturalWidth, domImg.naturalHeight)
+    else
+      img.on 'load', =>
+        callback.call(this, domImg.naturalWidth, domImg.naturalHeight)
+
+this.ImageFile = ImageFile