apps: more intelligent application choosing

ranger can now check whether an application is installed
on the system and choose the best available application out of
a list. ("either" method)

3 files changed, 73 insertions, 6 deletions

diff --git a/ranger/applications.py b/ranger/applications.py
index 5f267a42..e5a5fc4e 100644
--- a/ranger/applications.py
+++ b/ranger/applications.py
@@ -19,12 +19,14 @@ This module faciliates starting of new processes.
 import os, sys
 from ranger.ext.waitpid_no_intr import waitpid_no_intr
 from subprocess import Popen, PIPE
+from ranger.ext.iter_tools import flatten
+from ranger.shared import FileManagerAware
 
 devnull = open(os.devnull, 'a')
 
 ALLOWED_FLAGS = 'sdpSDP'
 
-class Applications(object):
+class Applications(FileManagerAware):
 	"""
 	This class contains definitions on how to run programs and should
 	be extended in ranger.defaults.apps
@@ -59,6 +61,30 @@ class Applications(object):
 		return ('vim', ) + tuple(context)
 	"""
 
+	def _meets_dependencies(self, fnc):
+		try:
+			deps = fnc.dependencies
+		except AttributeError:
+			return True
+
+		for dep in deps:
+			if hasattr(dep, 'dependencies') \
+			and not self._meets_dependencies(dep):
+				return False
+			if dep not in self.fm.executables:
+				return False
+
+		return True
+
+	def either(self, context, *args):
+		for app in args:
+			try:
+				application_handler = getattr(self, 'app_' + app)
+			except AttributeError:
+				continue
+			if self._meets_dependencies(application_handler):
+				return application_handler(context)
+
 	def app_self(self, context):
 		"""Run the file itself"""
 		return "./" + context.file.basename
@@ -268,4 +294,11 @@ def tup(*args):
 	is equivalent to:
 	tup('a', *some_iterator)
 	"""
-	return tuple(args)
+	return args
+
+def depends_on(*args):
+	args = tuple(flatten(args))
+	def decorator(fnc):
+		fnc.dependencies = args
+		return fnc
+	return decorator
diff --git a/ranger/defaults/apps.py b/ranger/defaults/apps.py
index 5117a027..5c4174ab 100644
--- a/ranger/defaults/apps.py
+++ b/ranger/defaults/apps.py
@@ -12,6 +12,7 @@
 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 # OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
+import os
 from re import compile, VERBOSE
 from ranger.applications import *
 
@@ -27,7 +28,7 @@ class CustomApplications(Applications):
 
 		if f.extension is not None:
 			if f.extension in ('pdf'):
-				return self.app_apvlv(c)
+				return self.either(c, 'evince', 'apvlv')
 			if f.extension in ('swc', 'smc'):
 				return self.app_zsnes(c)
 
@@ -41,7 +42,7 @@ class CustomApplications(Applications):
 		if f.video or f.audio:
 			if f.video:
 				c.flags += 'd'
-			return self.app_mplayer(c)
+			return self.either(c, 'mplayer', 'totem')
 		
 		if f.image:
 			return self.app_feh(c)
@@ -53,22 +54,35 @@ class CustomApplications(Applications):
 	def app_pager(self, c):
 		return tup('less', *c)
 
+	@depends_on('vim')
 	def app_vim(self, c):
 		return tup('vim', *c)
 
-	app_editor = app_vim
+	def app_editor(self, c):
+		default_editor = os.environ['EDITOR']
+		parts = default_editor.split()
+		exe_name = os.path.basename(parts[0])
+		log(exe_name)
 
+		if exe_name in self.fm.executables:
+			return tuple(parts) + tuple(c)
+
+		else:
+			return self.either(c, 'vim', 'emacs', 'nano')
+
+	@depends_on(app_editor, Applications.app_self)
 	def app_edit_or_run(self, c):
 		if c.mode is 1:
 			return self.app_self(c)
 		return self.app_editor(c)
 
+	@depends_on('mplayer')
 	def app_mplayer(self, c):
 		if c.mode is 1:
 			return tup('mplayer', *c)
 
 		elif c.mode is 2:
-			args = "mplayer -fs -sid 0 -vfm ffmpeg -lavdopts" \
+			args = "mplayer -fs -sid 0 -vfm ffmpeg -lavdopts " \
 					"lowres=1:fast:skiploopfilter=all:threads=8".split()
 			args.extend(c)
 			return tup(*args)
@@ -79,6 +93,7 @@ class CustomApplications(Applications):
 		else:
 			return tup('mplayer', '-fs', *c)
 
+	@depends_on('feh')
 	def app_feh(self, c):
 		arg = {1: '--bg-scale', 2: '--bg-tile', 3: '--bg-center'}
 
@@ -90,16 +105,19 @@ class CustomApplications(Applications):
 			return tup('gimp', *c)
 		return tup('feh', *c)
 
+	@depends_on('aunpack')
 	def app_aunpack(self, c):
 		if c.mode is 0:
 			c.flags += 'p'
 			return tup('aunpack', '-l', c.file.path)
 		return tup('aunpack', c.file.path)
 	
+	@depends_on('apvlv')
 	def app_apvlv(self, c):
 		c.flags += 'd'
 		return tup('apvlv', *c)
 
+	@depends_on('make')
 	def app_make(self, c):
 		if c.mode is 0:
 			return tup("make")
@@ -108,12 +126,15 @@ class CustomApplications(Applications):
 		if c.mode is 2:
 			return tup("make", "clear")
 	
+	@depends_on('firefox')
 	def app_firefox(self, c):
 		return tup("firefox")
 
+	@depends_on('javac')
 	def app_javac(self, c):
 		return tup("javac", *c)
 	
+	@depends_on('java')
 	def app_java(self, c):
 		def strip_extensions(file):
 			if '.' in file.basename:
@@ -122,15 +143,19 @@ class CustomApplications(Applications):
 		files_without_extensions = map(strip_extensions, c.files)
 		return tup("java", files_without_extensions)
 	
+	@depends_on('zsnes')
 	def app_zsnes(self, c):
 		return tup("zsnes", c.file)
 	
+	@depends_on('evince')
 	def app_evince(self, c):
 		return tup("evince", *c)
 	
+	@depends_on('wine')
 	def app_wine(self, c):
 		return tup("wine", c.file)
 
+	@depends_on('totem')
 	def app_totem(self, c):
 		if c.mode is 0:
 			return tup("totem", "--fullscreen", *c)
diff --git a/ranger/fm.py b/ranger/fm.py
index 3471dcd4..7993a207 100644
--- a/ranger/fm.py
+++ b/ranger/fm.py
@@ -18,6 +18,7 @@ from collections import deque
 from ranger.actions import Actions
 from ranger.container import Bookmarks
 from ranger.ext.relpath import relpath_conf
+from ranger.ext.get_executables import get_executables
 from ranger import __version__
 from ranger.fsobject import Loader
 
@@ -36,11 +37,19 @@ class FM(Actions):
 		self.bookmarks = bookmarks
 		self.tags = tags
 		self.loader = Loader()
+		self._executables = None
 		self.apps = self.settings.apps.CustomApplications()
 
 		from ranger.shared import FileManagerAware
 		FileManagerAware.fm = self
 
+	def get_executables(self):
+		if self._executables is None:
+			self._executables = get_executables()
+		return self._executables
+
+	executables = property(get_executables)
+
 	def initialize(self):
 		"""If ui/bookmarks are None, they will be initialized here."""
 		from ranger.fsobject.directory import Directory