[WIP] Add options to automatically open and close previews

lib/main.coffee

@@ -12,6 +12,7 @@ module.exports =
   activate: ->
     @disposables = new CompositeDisposable()
     @commandSubscriptions = new CompositeDisposable()
+    @destroyedItems = new Set()
 
     @disposables.add atom.config.observe 'markdown-preview.grammars', (grammars) =>
       @commandSubscriptions.dispose()
@@ -59,6 +60,40 @@ module.exports =
       else
         @createMarkdownPreviewView(filePath: path)
 
+    @disposables.add atom.workspace.getCenter().onDidStopChangingActivePaneItem (item) =>
+      editor = atom.workspace.getActiveTextEditor()
+      return if @lastActiveEditor is editor
+
+      if atom.config.get('markdown-preview.automaticallyClosePreview') and @lastActiveEditor
+        # Do not close preview if we change focus from the editor to the preview itself
+        unless isMarkdownPreviewView(item) and item.editorId is @lastActiveEditor.id.toString()
+          @removePreviewForEditor(@lastActiveEditor)
+
+      @lastActiveEditor = editor
+
+      if editor? and atom.config.get('markdown-preview.automaticallyOpenPreview')
+        uri = @uriForEditor(editor)
+        return if atom.workspace.paneForURI(uri)? # Preview already exists
+
+        openPreview = true
+        @destroyedItems.forEach (destroyedItem) ->
+          return unless isMarkdownPreviewView(destroyedItem) and openPreview
+          # Do not open preview for a text editor whose preview we just closed
+          openPreview = false if destroyedItem.editorId is editor.id.toString()
+
+        @destroyedItems.clear()
+        return unless openPreview
+
+        grammars = atom.config.get('markdown-preview.automaticPreviewGrammars') ? []
+        return unless editor.getGrammar().scopeName in grammars
+
+        @addPreviewForEditor(editor, atom.workspace.paneForItem(item))
+
+    @disposables.add atom.workspace.getCenter().onDidDestroyPaneItem ({item}) =>
+      @destroyedItems.add(item) unless item is @lastRemovedPreview
+      if atom.config.get('markdown-preview.automaticallyClosePreview')
+        @removePreviewForEditor(item) if atom.workspace.isTextEditor(item)
+
   deactivate: ->
     @disposables.dispose()
     @commandSubscriptions.dispose()
@@ -88,14 +123,15 @@ module.exports =
     uri = @uriForEditor(editor)
     previewPane = atom.workspace.paneForURI(uri)
     if previewPane?
-      previewPane.destroyItem(previewPane.itemForURI(uri))
+      @lastRemovedPreview = previewPane.itemForURI(uri)
+      previewPane.destroyItem(@lastRemovedPreview)
       true
     else
       false
 
-  addPreviewForEditor: (editor) ->
+  addPreviewForEditor: (editor, previousActivePane) ->
     uri = @uriForEditor(editor)
-    previousActivePane = atom.workspace.getActivePane()
+    previousActivePane ?= atom.workspace.getActivePane()
     options =
       searchAllPanes: true
     if atom.config.get('markdown-preview.openPreviewInSplitPane')

package.json

@@ -23,28 +23,52 @@
     "MarkdownPreviewView": "createMarkdownPreviewView"
   },
   "configSchema": {
-    "breakOnSingleNewline": {
-      "type": "boolean",
-      "default": false,
-      "description": "In Markdown, a single newline character doesn't cause a line break in the generated HTML. In GitHub Flavored Markdown, that is not true. Enable this config option to insert line breaks in rendered HTML for single newlines in Markdown source."
-    },
     "liveUpdate": {
       "type": "boolean",
+      "order": 0,
       "default": true,
       "description": "Re-render the preview as the contents of the source changes, without requiring the source buffer to be saved. If disabled, the preview is re-rendered only when the buffer is saved to disk."
     },
+    "useGitHubStyle": {
+      "title": "Use GitHub.com style",
+      "type": "boolean",
+      "order": 1,
+      "default": false,
+      "description": "Use the same CSS styles for preview as the ones used on GitHub.com."
+    },
     "openPreviewInSplitPane": {
       "type": "boolean",
+      "order": 2,
       "default": true,
       "description": "Open the preview in a split pane. If disabled, the preview is opened in a new tab in the same pane."
     },
+    "automaticallyOpenPreview": {
+      "type": "boolean",
+      "order": 3,
+      "default": false,
+      "description": "Automatically open the preview when a Markdown file is focused."
+    },
+    "automaticallyClosePreview": {
+      "type": "boolean",
+      "order": 4,
+      "default": false,
+      "description": "Automatically close the preview when its corresponding file is no longer focused."
+    },
+    "breakOnSingleNewline": {
+      "type": "boolean",
+      "order": 5,
+      "default": false,
+      "description": "In Markdown, a single newline character doesn't cause a line break in the generated HTML. In GitHub Flavored Markdown, that is not true. Enable this config option to insert line breaks in rendered HTML for single newlines in Markdown source."
+    },
     "allowUnsafeProtocols": {
       "type": "boolean",
+      "order": 6,
       "default": false,
       "description": "Allow HTML attributes to use protocols normally considered unsafe such as `file://` and absolute paths on Windows."
     },
     "grammars": {
       "type": "array",
+      "order": 7,
       "default": [
         "source.gfm",
         "source.litcoffee",
@@ -55,11 +79,14 @@
       ],
       "description": "List of scopes for languages for which previewing is enabled. See [this README](https://github.com/atom/spell-check#spell-check-package-) for more information on finding the correct scope for a specific language."
     },
-    "useGitHubStyle": {
-      "title": "Use GitHub.com style",
-      "type": "boolean",
-      "default": false,
-      "description": "Use the same CSS styles for preview as the ones used on GitHub.com."
+    "automaticPreviewGrammars": {
+      "type": "array",
+      "order": 8,
+      "default": [
+        "source.gfm",
+        "source.litcoffee"
+      ],
+      "description": "Only automatically open previews for the given list of scopes."
     }
   }
 }