Improve project handling

Keep track of GitKraken instances; either spawn one per project or limit to a single instance.

Signed-off-by: Daniel Bayley <daniel.bayley@me.com>

README.md

 [Atom] + [GitKraken]
 ====================
-Open the current Atom project in [GitKraken](http://gitkraken.com). This can be activated from the Packages menu, command palette, tree view or the git branch indicator in the status bar.
+Open the current [Atom] project in _[GitKraken]_.
+
+This can be activated from the _Packages_ menu, _command palette_, from the context menu on the root project folder in _tree view_, or the git _branch_ indicator in the _status bar_.
+
+An instance of _GitKraken_ will be spawned for each project by default, but can be configured in the package settings to only ever run a single instance of the application.
 
 Install
 -------
-`apm install gitkraken` or search "gitkraken" under packages within Atom.
+`apm install gitkraken` or search "kraken" under packages within Atom.
 
 License
 -------

index.coffee

-{exec} = require 'child_process'
+{execSync, exec} = require 'child_process'
+{writeFile, unlink} = require 'fs'
 
+tmp = '/tmp/GitKraken.json'
+id = 'com.axosoft.GitKraken'
+selector = '[class^="status-bar"] .git-branch'
+
+#-------------------------------------------------------------------------------
 module.exports =
 	#os: process.platform
 	#timeout:
 		#timeout: 10000
 		#killSignal: 'SIGKILL'
-	selector: '[class^="status-bar"] .git-branch'
-
 	subs: null
 	activate: ->
-		SubAtom = require 'sub-atom' # {CompositeDisposable} = require 'atom'
-		@subs = new SubAtom #CompositeDisposable
+		SubAtom = require 'sub-atom'
+		@subs = new SubAtom
 #-------------------------------------------------------------------------------
 
 		@subs.add atom.commands.add 'atom-workspace',
 			'gitkraken:release': => @open()
 
 		atom.packages.onDidActivateInitialPackages =>
-			@subs.add 'status-bar','click', @selector, @open
+			@subs.add 'status-bar','click', selector, @open
 
+#-------------------------------------------------------------------------------
 	open: ->
 		{path} = atom.project.getDirectories()[0]
-		exec "open -b com.axosoft.GitKraken --args -p '#{path}'" #, @timeout
+
+		if atom.config.get 'gitkraken.singleInstance'
+			exec "pkill GitKraken; sleep .1 && open -Fb #{id} --args -p '#{path}'" #, @timeout
+		else
+			projects = {}
+			try
+				projects = require tmp
+				execSync "ps #{projects[path]} | grep -q GitKraken &&
+					open -b #{id} --args -p '#{path}'"
+			catch
+				pid = execSync "open -nb #{id} --args -p '#{path}' & echo $!"
+				projects[path] = (parseInt pid) + 1
+				writeFile tmp, JSON.stringify projects
 
 #-------------------------------------------------------------------------------
-	deactivate: -> @subs.dispose()
+	deactivate: ->
+		@subs.dispose()
+		unlink tmp

package.json

@@ -22,10 +22,17 @@
   "os": [
     "darwin"
   ],
+  "dependencies": {
+    "sub-atom": "^1.1.0"
+  },
   "engines": {
     "atom": "*"
   },
-  "dependencies": {
-    "sub-atom": "^1.1.0"
+  "configSchema": {
+    "singleInstance": {
+      "description": "Limit to a single instance of the application, else spawn one per project.",
+      "type": "boolean",
+      "default": false
+    }
   }
 }